KR20190099523A - Shape Adaptive Rope Flexible Supercapacitor - Google Patents

Abstract

(a) a first conductive porous rod having pores and a first electrode active material (eg, activated carbon or an isolated graphene sheet) present in the pores of the first porous rod and a first mixture of first electrolyte 1 electrode; (b) a porous separator casing the first electrode to form a separator-protected first electrode; (c) a second electrode comprising a second conductive porous bar having pores and a second mixture of the second electrode active material and the second electrolyte present in the pores of the second porous bar; And (d) a protective sheath surrounding the casing or casing of the braid or yarn, wherein the separator-protected first and second electrodes are combined to form a braid or twisted yarn.

Description

Shape Adaptive Rope Flexible Supercapacitor

Cross Reference to Related Application

This application claims priority to US Patent Application 15 / 398,416, filed January 4, 2017, and US Patent Application 15 / 398,421, filed January 4, 2017, which is incorporated herein by reference. .

Technical field

The present invention relates generally to the field of supercapacitors or ultracapacitors, and more particularly to rope-type supercapacitors that are flexible and shape-conformal.

Conventional supercapacitors and batteries (e.g., 18650 type cylindrical cells, rectangular pouch cells, and square cells) are mechanically rigid, and these non-flexible features can be adapted for use in confined spaces or for use in wearable devices, or The possibilities have been severely limited. Shape adaptive flexible power sources can be used to overcome these design limitations. This new power source will enable the development of next generation electronic devices such as smart mobile devices, roll-up displays, wearable devices, and biomedical sensors. The shape adaptive flexible power source will also save the weight and space of the electric vehicle.

Electrochemical capacitors (EC), also known as ultracapacitors or supercapacitors, are being considered for use in hybrid electric vehicles (EVs), where the electrochemical capacitors are best used to make cell-power differences commercially viable. A large technical obstacle, which can assist the battery used in electric vehicles to provide the burst of power required for rapid acceleration, will still be used for driving, but (the ability to release energy much faster than the battery). Supercapacitors will have an effect whenever the vehicle needs to be accelerated for joining, passing, emergency maneuvers, and hill climbing. The EC must also store enough energy to provide an acceptable driving range. To be cost, volume, and weight effective relative to additional cell capacity, they must combine adequate energy density (volume and weight) and power density with long cycle life, and must also meet cost goals.

EC is also accepted in the electronics industry as system designers become familiar with the attributes and benefits of EC. EC was originally developed to provide a large burst of driving energy for orbital lasers. In complementary metal oxide semiconductor (CMOS) memory backup applications, for example, one parrot EC with a volume of only 1/2 cubic inch can replace nickel-cadmium or lithium cells and can provide months of backup power. Can provide. For a given applied voltage, the energy stored in the EC associated with a given charge is half the energy that can be stored in the corresponding cell system for the same charge path. Nevertheless, EC is an extremely attractive power source. Compared to batteries, they do not require maintenance, provide much higher cycle life, require very simple charging circuits, have no "memory effect" and are generally much safer. Physical rather than chemical energy storage is a major cause of their safe operation and exceptionally high cycle life. Perhaps most importantly, the capacitor provides a higher power density than the cell.

The high volumetric capacitance density of EC (10-100 times larger than conventional capacitors) compared to conventional capacitors results from the use of porous electrodes to create a very effective "plate area" and from storing energy in the diffusion bilayer. Is derived. These bilayers, which are made naturally at the solid-electrolyte interface when voltage is added, have only a thickness of about 1 nm, thus forming a very effective "plate separation". Such supercapacitors are generally referred to as electric double layer capacitors (EDLC). Bilayer capacitors are based on high surface area electrode materials, such as activated carbon, immersed in a liquid electrolyte. Polarized bilayers are formed at the electrode-electrolyte interface providing high capacitance. This means that the noncapacitance of the supercapacitor is directly proportional to the specific surface area of the electrode material. This surface area must be accessible by the electrolyte and the resulting interfacial region must be large enough to accommodate the so-called electrical double layer charges.

In some ECs, the stored energy is further increased by the pseudocapacitance effect, which again occurs at the solid-electrolyte interface due to electrochemical phenomena such as redox charge transfer.

However, there are some serious technical issues associated with the latest technologies in EC or supercapacitors:

(1) With EC based on activated carbon electrodes, the experimentally measured capacitance is always much lower than the geometric capacitance calculated from the measured surface area and width of the dipole layer. For very high surface areas of carbon, typically only about 10 to 20 percent of the "theoretical" capacitance has been observed. This disappointing performance is related to the presence of micropores (less than 2 nm, usually less than 1 nm), which means that inaccessibility to some pores of the electrolyte, lack of wetness, and / or oppositely charged surfaces are less than about 1 to 2 nm. This is due to the inability to successfully form the bilayer in the distant pores. In activated carbon, depending on the carbon source and the heat treatment temperature, surprising amounts of surface may be such microporous shapes.

(2) Despite the high weight capacities at the electrode level (based only on the active material weight) as often claimed in the publications and patent literature, these electrodes unfortunately have a high capacity or pack level (total cell) in the supercapacitor cell. Energy storage device) by weight or pack weight). This is due to the idea in these reports that the actual mass feed of the electrode and the apparent density for the active material are too low. In most cases, the active material mass supply (area density) of the electrode is significantly lower than 10 mg / cm ² (area density = amount of active material per electrode cross-sectional area along the electrode thickness direction) and the apparent bulk density or tap density of the active material is In the case of large particles of activated carbon, it is usually less than 0.75 g / cm ^-3 (more typically less than 0.5 g / cm ^-3 , most typically less than 0.3 g / cm ^-3 ).

The low mass feed is mainly due to the inability to obtain thicker (thicker than 100-200 μm) electrodes using conventional slurry coating procedures. This is not as trivial as one might think, and in practice, electrode thickness is not a design parameter that can be arbitrarily changed freely to optimize cell performance. In contrast, thicker samples tend to be extremely brittle or poor in structural integrity, and will also require the use of large amounts of binder resin. These problems are particularly acute for electrodes based on graphene materials. It has not previously been possible to produce very porous graphene-based electrodes that are thicker than 150 μm and have pores in which the liquid electrolyte remains fully accessible. Low area density and low volume density (related to thin electrodes and poor packing density) result in a relatively low volumetric capacity and low volumetric energy density of the supercapacitor cell.

As the demand for smaller portable energy storage systems increases, there is a great interest in increasing the utilization of the volume of energy storage devices. New electrode materials and designs that allow for high volumetric capacitance and high mass feed are essential for achieving improved cell volumetric capacitance and energy density.

(3) Over the past decade, electrode materials with increased volumetric capacitance have been developed using materials based on porous carbon such as graphene, carbon nanotube-based composites, porous graphite oxide, and porous mesocarbons. Much work has been done to accomplish this. These experimental supercapacitors featuring such electrode materials can be charged and discharged at high speed and also exhibit large volume electrode capacitance (100-200 F / cm ³ , in most cases based on electrode volume), Their typical 1 mg / cm ² Active material mass feeds of less than 0.2 g / cm ^-3 , tap density of less than 0.2 g / cm ^-3 , and electrode thicknesses of tens of micrometers or less (<< 100 μm) are most commercially available electrochemical capacitors (ie, 10 mg / cm ² , 100-200 μm), which is significantly lower than those used, resulting in a relatively low area and volume capacitance and low volume energy density.

(4) In the case of graphene supercapacitors, there are additional problems to be solved, which are described below:

Nanographene materials have recently been found to exhibit particularly high thermal conductivity, high electrical conductivity, and high strength. Another outstanding feature of graphene is its particularly high specific surface area. The single graphene sheet is approximately 2,675 m ² / g (by liquid electrolyte) in contrast to the approximately 1,300 m ² / g outer surface area provided by the corresponding single wall CNT (inner surface is inaccessible by electrolyte). Accessible) outside specific surface area. The electrical conductivity of graphene is slightly higher than CNTs.

Applicants (A. Zhamu and B. Z. Jang) and their colleagues first studied nanomaterials based on graphene and other nanographite for supercapacitor applications [see references 1 to 5 below; The first patent application was filed in 2006 and issued in 2009]. Since 2008, researchers have begun to realize the importance of nanographene materials for supercapacitor applications.

List of references:

One. Lulu Song, A. Zhamu, Jiusheng Guo, and B. Z. Jang "Nano-scaled Graphene Plate Nanocomposites for Supercapacitor Electrodes" US Pat. No. 7,623,340 (11/24/2009).

2. Aruna Zhamu and Bor Z. Jang, "Process for Producing Nano-scaled Graphene Platelet Nanocomposite Electrodes for Supercapacitors," U.S. Patent Appl. No. 11 / 906,786 (10/04/2007).

3. Aruna Zhamu and Bor Z. Jang, "Graphite-Carbon Composite Electrodes for Supercapacitors" US Pat. Appl. No. 11 / 895,657 (08/27/2007).

4. Aruna Zhamu and Bor Z. Jang, "Method of Producing Graphite-Carbon Composite Electrodes for Supercapacitors" US Pat. Appl. No. 11 / 895,588 (08/27/2007).

5. Aruna Zhamu and Bor Z. Jang, "Graphene Nanocomposites for Electrochemical Cell Electrodes," U.S. Patent Appl. No. 12 / 220,651 (07/28/2008).

2.2 g/cm³, l = 100 nm, w = 100 nm, 및 t = 0.34 nm(단일 층)을 이용하여, 본 발명자들은 2,675 m²/g이라는 인상적인 S/m 값을 얻었으며, 이는 대부분의 상업적으로 입수가능한 카본블랙 또는 최신 기술의 수퍼커패시터에서 사용된 활성탄 물질보다 훨씬 더 크다. 두 개의 단일층 그래핀 시트가 적층되어 이중층 그래핀을 형성한다면, 비표면적은 1,345 m²/g으로 감소된다. 3층 그래핀의 경우, t =1 nm이고, S/m = 906 m²/g이다. 더 많은 층이 함께 적층된 경우, 비표면적은 더 현저히 감소될 것이다.However, each nanographene sheet tends to re-lay itself, effectively reducing the specific surface area that the electrolyte in the supercapacitor electrode can access. The importance of this graphene sheet overlap problem can be illustrated as follows: l (length) Х w (width) For nanographene platelets with a size of Х t (thickness) and a density ρ, the predicted surface area per unit mass is S / m = (2 / ρ) (1 / l + 1 / w + 1 / t ). ρ

Using 2.2 g / cm ³ , l = 100 nm, w = 100 nm, and t = 0.34 nm (single layer), we obtained an impressive S / m value of 2,675 m ² / g, which is the most It is much larger than the activated carbon materials used in commercially available carbon black or state of the art supercapacitors. If two single layer graphene sheets are stacked to form double layer graphene, the specific surface area is reduced to 1345 m ² / g. For three-layer graphene, t = 1 nm and S / m = 906 m ² / g. If more layers are stacked together, the specific surface area will be significantly reduced.

These calculations suggest that it is very important to find a way to prevent individual graphene sheets from relaminating, and even if they are partially relaminated, the resulting multilayer structure will still have inner layer pores of the appropriate size. These pores must be large enough to allow access by the electrolyte and to allow the formation of an electric double layer charge, which typically requires a pore size of at least 1 nm, more preferably at least 2 nm. However, these pore or internal graphene spaces must also be small enough to ensure a large tap density. Unfortunately, the typical tap density of graphene-based electrodes is less than 0.3 g / cm ³ , most typically << 0.1 g / cm ³ . The requirements of large pore sizes and high porosity levels and of high tap density are generally considered mutually exclusive in supercapacitors.

Another major technical obstacle to the use of graphene sheets as supercapacitor electrode active materials is that thicker active material layers can be deposited on the surface of a solid current collector (eg Al foil) using conventional graphene-solvent slurry coating procedures. Difficult to deposit on. In such electrodes, graphene electrodes typically require large amounts of binder resin (and thus significantly reduced active material ratio to inert or overhead material / component). In addition, any electrode made in this manner thicker than 50 μm is brittle and weak. There was no effective solution to this problem.

Thus, high active material mass feed (high area density), active material with high apparent density (high tap density), high electrode thickness without significantly reducing electron and ion transport rates (eg, without long electron transport distance), There is a clear and urgent need for supercapacitors with high volumetric capacitance, and high volumetric energy density. In the case of graphene-based electrodes, problems such as the relamination of graphene sheets, the demand for a large proportion of the binder resin, and the difficulty in producing thick graphene electrode layers must also be overcome.

Additionally, thick electrodes in conventional supercapacitors are also mechanically robust, but not flexible, not bendable, and do not adapt to the desired shape. As such, high volume / weight energy densities and mechanical flexibility appear to be mutually exclusive in conventional supercapacitors.

As the demand for smaller portable energy storage systems increases, there is a great interest in increasing the utilization of the volume of supercapacitors. New electrode materials and designs that enable high volume capacity and high mass feed are essential for achieving improved cell volume capacity and energy density for supercapacitors.

Thus, active materials with high active material mass feed (high area density), high apparent density (high tap density), without significantly reducing electron and ion transport rates (eg, without high electron transport resistance or long ion diffusion paths) There is a clear and urgent need for supercapacitors with high electrode thickness, high weight energy density, and high volumetric energy density. These properties must be achieved, with improved flexibility and shape adaptability of the resulting supercapacitors.

The present invention combines filament or rod anode and cathode electrodes that combine to form a braid or twist yarn shape (e.g., 2-ply, 3-ply, 4-ply, 5-ply yarn or braid, etc.). A rope-type supercapacitor is provided. The supercapacitor may be an electric double layer capacitor (EDLC, symmetrical or asymmetrical), pseudocapacitor, lithium ion capacitor, or sodium ion capacitor. Lithium ion capacitors or sodium ion capacitors may be used to pre-lithiated or pre-sodiumated anode active materials (i.e., terrestrial anodes) and cathodes (i.e., EDLC type cathodes) containing high surface area carbon materials such as activated carbon or graphene sheets. It contains.

The supercapacitor comprises (a) a first electrically conductive porous rod (or filament) having pores, and a first mixture of the first electrode active material and the first electrolyte, the first mixture comprising a first porous rod (eg For example, the first electrode, which is present in the pores of the filament-shaped foam; (b) a porous separator surrounding or encasing the first electrode to form a separator-protected first electrode; (c) a second electrically conductive porous rod having pores (e.g., filament shaped foam), and a second mixture of a second electrode active material and a second electrolyte, wherein the second mixture is formed of a second porous rod A second electrode, present in the pores, wherein the separator-protected first and second electrodes are combined in a helical manner to form a braid or twisted yarn; And (d) a protective casing or sheath surrounding or casing the braid or yarn. The second electrolyte may be the same or different than the first electrolyte. The pores in the first or second electrode preferably contain pores connected to one another and the porous rod / filament is preferably an open-cell foam.

The first active material and / or the second active material contain a plurality of particles of carbon material and / or a plurality of isolated graphene sheets, wherein the plurality of graphene sheets are single layer graphene or 1 to 10 graphene faces each, respectively. Containing a hydrophobic layer of graphene, wherein the plurality of particles of carbon material or graphene sheet have a specific surface area of at least 500 m ² / g (preferably greater than 1,000 m ² / g, more preferably measured in the dry state) Is greater than 2,000 m ² / g). These isolated graphene sheets are not part of the graphene foam (where the porous rod is for graphene-based foam structures). These isolated graphene sheets are true electrode active materials, separately or in addition to the porous rod.

In some preferred embodiments, the first or second electrode active material contains activated carbon particles or isolated graphene sheets having a length or width less than 1 μm for easy impregnation into the pores of the first or second electrode, The graphene sheet includes pristine graphene, graphene oxide, reduced graphene oxide, graphene fluoride, nitrogenated or nitrogen doped graphene, hydrogenated or hydrogen doped graphene, boron doped graphene, chemical Functionalized graphene, or a combination thereof.

In some embodiments, the first or second electrode may further contain a redox pair partner material selected from metal oxides, conductive polymers, organic materials, non-graphene carbon materials, inorganic materials, or combinations thereof. . The partner material is combined with graphene or activated carbon to form redox pairs to provide pseudocapacitance.

In certain embodiments, the first or second electrode, (a) graphene sheet alone; (b) graphene sheets mixed with a porous carbon material (eg, activated carbon); (c) graphene sheets mixed with partner material to form redox pairs with graphene sheets to develop pseudocapacitance; Or (d) a porous carbon material and a graphene sheet mixed with a graphene sheet or a partner material forming a redox pair with the porous carbon material to develop pseudocapacitance as the only electrode active material in the first or second electrode and There is no other electrode active material in the first or second electrode.

The supercapacitor of the present invention may further include a porous separator surrounding or casing the second electrode to form a separator-protected second electrode. As such, both the first and second electrodes, each with an active material-electrolyte mixture pre-impregnated into the pores of the porous rod, are cascaded by the porous separator before braiding or twisting together to form braids or twisted yarns. Preferably, the two electrodes are packed as closely as possible to maximize the contact or interface area between the electrodes.

In certain embodiments, the rope-type supercapacitor further comprises a third electrolyte disposed between the braid or yarn and the protective sheath. The third electrolyte may be the same as or different from the first electrolyte or the second electrolyte.

In such a supercapacitor, the first electrode may be a negative electrode (or anode) and the second electrode may be a positive electrode (or cathode). Alternatively, the second electrode is a negative electrode or anode and the first electrode is a positive electrode or cathode.

The supercapacitor may include a plurality of first electrodes and / or a plurality of second electrodes. That is, the supercapacitors may have a plurality of anodes and / or a plurality of cathode filaments / rods that are combined together to form a braid or twisted structure. At least one electrode is an anode and at least one electrode is a cathode.

In certain embodiments, rope-type supercapacitors have a length and diameter or thickness with a length to diameter or length to thickness aspect ratio of at least 5, preferably at least 10, and more preferably at least 20.

In some embodiments, the supercapacitor comprises (a) a first electrically conductive rod (not a porous foam) and a first mixture of the first electrode active material and the first electrolyte, wherein the first mixture is on the first electrode rod. Or deposited in the first electrode; (b) a porous separator surrounding or casing the first electrode to form a separator-protected first electrode; (c) a second electrically conductive rod that is porous and has pores and a second mixture of the second electrode active material and the second electrolyte, wherein the second mixture is present in the pores of the porous second rod and is separator-protected The first electrode and the second electrode being twisted together or combined in a spiral or twisted manner to form a braid or twisted yarn; And (d) a protective casing or sheath surrounding or casing the yarn or braid.

The first active material and / or the second active material has a high specific surface area (500 m ² / g or more, preferably more than 1,000 m ² / g, more preferably more than 2,000 m ² / g) of a plurality of particles of carbon Material and / or a plurality of isolated graphene sheets. Again, these isolated graphene sheets are not part of the graphene foam (if the porous rod is a graphene-based foam structure). These isolated graphene sheets are truly electrode active materials separately from, or in addition to, the porous rod. In addition, the first or second electrode may further contain a redox pair partner material selected from metal oxides, conductive polymers, organic materials, non-graphene carbon materials, inorganic materials, or combinations thereof. The partner material is combined with graphene or activated carbon to form redox pairs to provide pseudocapacitance.

Likewise, the supercapacitor of the present invention may further include a porous separator that surrounds or casks the second electrode to form a separator-protected second electrode. In certain embodiments, the supercapacitor further comprises a third electrolyte disposed between the braid or yarn and the protective sheath. The third electrolyte may be the same as or different from the first electrolyte or the second electrolyte.

In some embodiments of the invention, the first or second electrode (but not both) comprises a conductive rod (not a foam) and the first or second mixture is coated or deposited on the surface of such conductive rod. Such rods may simply be metal wires, conductive polymer fibers or yarns, carbon or graphite fibers or yarns, multiple wires, fibers or yarns.

In certain embodiments, the rope-shaped supercapacitor has a first end and a second end, and the first electrode is at least one metal wire, conductive carbon / graphite fiber, or embedded in, connected to, or integrated with the first electrode. And a first terminal connector comprising conductive polymer fibers. In certain preferred embodiments, the at least one metal wire, conductive carbon / graphite fibers, or conductive polymer fibers run approximately from the first end to the second end. Preferably, the wire or fiber protrudes from the first or second end to be a terminal tab for connecting to an electronic device or an external circuit or load.

Alternatively or additionally, the rope-shaped supercapacitor has a first end and a second end, the second electrode comprising at least one metal wire, conductive carbon / graphite fibers, embedded, connected or integrated in the second electrode, Or a second terminal connector comprising conductive polymer fibers. In certain embodiments, the at least one metal wire, conductive carbon / graphite fibers, or conductive polymer fibers run approximately from the first end to the second end. Preferably, the wire or fiber protrudes from the first or second end to be a terminal tab for connecting to an electronic device or an external circuit or load.

The first or second electrically conductive porous rod can be a metal foam, metal web, metal fiber mat, metal nanowire mat, metal wire braid, conductive polymer fiber mat, conductive polymer foam, conductive polymer fiber braid, conductive polymer coated fiber foam, From carbon foam, graphite foam, carbon aerogel, graphene aerogel, carbon zero gel, graphene foam, graphene oxide foam, reduced graphene oxide foam, carbon fiber foam, graphite fiber foam, exfoliated graphite foam, or combinations thereof It may contain the porous foam of choice. These foams can be made into shape adaptable structures that deform very well.

These foam structures are readily available at porosity levels of greater than 50%, usually preferably greater than 70%, more typically greater than 80%, even more usually preferably greater than 90%, most preferably greater than 95%. (Graphene aerogels can exceed 99% porosity levels). The skeletal structure (pore walls) of these foams form a 3D network of electron conduction paths, while the pores will receive a large portion of the electrode active material (anode active material of anode or cathode active material of cathode) without the use of conductive additives or binder resins. Can be.

The foam rods / filaments may have a cross section of circular, oval, rectangular, square, hexagonal, hollow, or irregular shapes. There is no particular limitation on the cross-sectional shape of the foam structure. Supercapacitors have a length and diameter or thickness and aspect ratio (length / thickness or length / diameter ratio) of greater than 10, preferably greater than 15, more preferably greater than 20, more preferably greater than 30, even more Preferably it has a rope shape of more than 50 or 100. There is no restriction on the length or diameter (or thickness) of the rope cell. The thickness or diameter is usually preferably 100 nm to 10 cm, more preferably 1 μm to 1 cm, most typically 10 μm to 1 mm. The length can range from 1 μm to tens of meters or (if desired) even hundreds of meters.

In certain embodiments of the invention, the supercapacitor comprises (a) particles of natural graphite, artificial graphite, mesocarbon microbeads (MCMB), and carbon; (b) silicon (Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), zinc (Zn), aluminum (Al), nickel (Ni), cobalt ( Co), manganese (Mn), titanium (Ti), iron (Fe), and cadmium (Cd); (c) stoichiometric or nonstoichiometric alloys or intermetallic compounds of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, or Cd with other elements; (d) oxides, carbides, nitrides, sulfides, phosphides, seleniums of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Fe, Ni, Co, Ti, Mn, or Cd, and mixtures or complexes thereof Cargo, and telluride; And a lithium ion capacitor or sodium ion capacitor having an anode active material selected from the group consisting of a prelithiated or presodiumated form of a combination thereof.

Lithium ion capacitors or sodium ion capacitors are anode active materials, pure graphene, graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated From prelithiated or pre-sodiumated forms of graphene, boron doped graphene, nitrogen doped graphene, chemically functionalized graphene, physically or chemically activated or etched forms thereof, or combinations thereof Optionally, it may contain prelithiated or pre-sodiumated graphene sheets.

In some embodiments, the supercapacitors are petroleum coke, carbon black, amorphous carbon, activated carbon, hard carbon, soft carbon, template carbon, hollow carbon nanowires, hollow carbon spheres, sodium titanate, NaTi ₂ (PO ₄ ) ₃ , Na ₂ Ti ₃ O ₇ , Na ₂ C ₈ H ₄ O ₄ , Na ₂ TP, Na _x TiO ₂ (x = 0.2 to 1.0), Na ₂ C ₈ H ₄ O ₄ , carboxylate, C ₈ H ₄ Na ₂ O ₄ , C ₈ H ₆ O ₄ , C ₈ H ₅ NaO ₄ , C ₈ Na ₂ F ₄ O ₄ , C ₁₀ H ₂ Na ₄ O ₈ , C ₁₄ H ₄ O ₆ , C ₁₄ H ₄ Na ₄ O ₈ , or a sodium ion capacitor having an anode active material selected from the combination thereof.

In some preferred embodiments, the second or first electrode active material is lithium cobalt oxide, doped lithium cobalt oxide, lithium nickel oxide, doped lithium nickel oxide, lithium manganese oxide, doped lithium manganese oxide, lithium vanadium oxide, doped Lithium intercalation compounds selected from the group consisting of lithium vanadium oxide, lithium mixed metal oxide, lithium iron phosphate, lithium vanadium phosphate, lithium manganese phosphate, lithium mixed metal phosphate, metal sulfides, lithium selenide, lithium polysulfide and combinations thereof It contains a lithium absorbing compound.

-MnO₂, Na_xK_(1-x)MnO₂, Na_{0 . 44}MnO₂, Na₀.₄₄MnO₂/C, Na₄Mn₉O₁₈, NaFe₂Mn(PO₄)₃, Na₂Ti₃O₇, Ni_{1 / 3}Mn_{1 / 3}Co_{1 / 3}O₂, Cu_{0 . 56}Ni₀.₄₄HCF, NiHCF, Na_xMnO₂, NaCrO₂, KCrO₂, Na₃Ti₂(PO₄)₃, NiCo₂O₄, Ni₃S₂/FeS₂, Sb₂O₄, Na₄Fe(CN)₆/C, NaV_{1 - x}Cr_xPO₄F, Se_zS_y(y/z = 0.01 내지 100), Se, 나트륨 폴리설파이드, 황, 알루오석, 또는 이들의 조합으로부터 선택되는 나트륨 삽입 화합물 또는 칼륨 삽입 화합물을 함유한다(x는 0.1 내지 1.0임).In certain embodiments, the second or first electrode active material is NaFePO ₄ , Na _(1-x) K _x PO ₄ , KFePO ₄ , Na _0.7 FePO ₄ , Na _{1 . 5 VOPO 4 F 0 .5, Na} 3 V 2 (PO 4) 3, Na 3 V 2 (PO 4) 2 F 3, Na 2 FePO 4 F, NaFeF 3, NaVPO 4 F, KVPO 4 F, Na 3 V ₂ (PO ₄ ) ₂ F ₃ , Na _{1 . 5 VOPO 4 F 0 .5, Na} 3 V 2 (PO 4) 3, NaV 6 O 15, Na x VO 2, Na 0. ₃₃ V ₂ O ₅ , Na _x CoO ₂ , Na _2/3 [Ni _1/3 Mn _2/3 ] O ₂ , Na _x (Fe _1/2 Mn _1/2 ) O ₂ , Na _x MnO ₂ ,

-MnO ₂ , Na _x K _(1-x) MnO ₂ , Na _{0 . 44} MnO ₂ , Na ₀ . _{44 MnO 2 / C, Na 4} Mn 9 O 18, NaFe 2 Mn (PO 4) 3, Na 2 Ti 3 O 7, Ni 1/3 Mn 1/3 Co 1/3 O 2, Cu 0. ₅₆ Ni ₀ . ₄₄ HCF, NiHCF, Na _x MnO ₂ , NaCrO ₂ , KCrO ₂ , Na ₃ Ti ₂ (PO ₄ ) ₃ , NiCo ₂ O ₄ , Ni ₃ S ₂ / FeS ₂ , Sb ₂ O ₄ , Na ₄ Fe (CN) _{6 / C, NaV 1 - x} Cr x PO 4 F, Se z S y (y / z = 0.01 to 100), Se, sodium polysulfide, sulfur, aluminate ohseok, or a sodium insertion compound, or selected from combinations of these Potassium insertion compound ( x is from 0.1 to 1.0).

The first electrolyte and / or the second electrolyte may contain a lithium salt or sodium salt dissolved in a liquid solvent, and the liquid solvent is water, an organic solvent, an ionic liquid, or a mixture of an organic solvent and an ionic liquid. The liquid solvent may be mixed with the polymer to form a polymer gel.

Preferably, the first electrolyte and / or the second electrolyte is greater than 2.5 M (preferably greater than 3.0 M, more preferably greater than 3.5 M, even more preferably greater than 5.0 M, even more preferably greater than 7.0 M, Most preferably it contains a lithium salt or sodium salt dissolved in a liquid solvent having a salt concentration above 10 M, up to 15 M).

In the alkali metal battery of the present invention, the electrically conductive porous rod of the first or second electrode has at least 90% by volume of pores, and the first or second electrode has a diameter or thickness of 200 μm or more or at least of the entire battery cell. The active material mass supply amount (anode or cathode active material) occupies 30% by weight or volume%, or the sum of the first electrode active material and the second electrode active material comprises at least 50% by weight or volume% of the entire battery cell.

In some preferred embodiments, the first or second electrically conductive porous rod has at least 95% by volume pores and the first or second electrode has a diameter or thickness of at least 300 μm or at least 35% by weight of the entire battery cell or It has an active material mass supply amount that occupies volume%, or the sum of the first electrode active material and the second electrode active material accounts for at least 60 wt% or volume% of the entire battery cell.

In some preferred embodiments, the first or second electrode active material comprises an alkali metal insertion compound or an alkali metal absorbing compound selected from inorganic materials, organic or polymeric materials, metal oxides / phosphates / sulfides, or combinations thereof. This compound may be an anode active material (eg lithium titanate or lithiated graphite) in a lithium ion capacitor, the cathode being of EDLC type (eg activated carbon) with a high specific surface area. Metal oxides / phosphates / sulfides are VO ₂ , Li _x VO ₂ , V ₂ O ₅ , Li _x V ₂ O ₅ , V ₃ O ₈ , Li _x V ₃ O ₈ , Li _x V ₃ O ₇ , V ₄ O ₉ Vanadium oxide selected from the group consisting of Li _x V ₄ O ₉ , V ₆ O ₁₃ , Li _x V ₆ O ₁₃ , doped forms thereof, derivatives thereof, and combinations thereof (wherein 0.1 <x <5).

This compound may be an inorganic material selected from transition metal dichalcogenides, transition metal trichalcogenides, or combinations thereof. Preferably, the inorganic material is selected from TiS ₂ , TaS ₂ , MoS ₂ , NbSe ₃ , MnO ₂ , CoO ₂ , iron oxide, vanadium oxide, or a combination thereof. In some specific embodiments, the inorganic material comprises (a) bismuth selenide or bismuth telluride, (b) transition metal dichalcogenide or trichalcogenide, (c) niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium Sulfides, selenides, or tellurides of cobalt, manganese, iron, nickel or transition metals; (d) boron nitride, or (e) combinations thereof.

The redox pair partner material may be selected from alkali metal insertion compounds or alkali metal absorbing compounds selected from metal carbides, metal nitrides, metal borides, metal dichalcogenides, or combinations thereof. More specifically, the cathode is an oxide of niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, vanadium, chromium, cobalt, manganese, iron or nickel, which is nanowire, nanodisk, nanoribbon, or nanoplate shaped, It contains an alkali metal insertion compound or an alkali metal absorbing compound, selected from dichalcogenides, trichalcogenides, sulfides, selenides, or tellurides.

In some embodiments, the redox pair partner material comprises (a) bismuth selenide or bismuth telluride, (b) transition metal dichalcogenide or trichalcogenide, (c) niobium, zirconium, molybdenum, hafnium, tantalum, Sulfides, selenides, or tellurides of tungsten, titanium, cobalt, manganese, iron or nickel, or transition metals; (d) a nanodisk, nanoplate, nanocoating or nanosheet of inorganic material selected from boron nitride, or (e) combinations thereof, wherein the disc, plate, or sheet is used to ensure a high specific surface area. It has a thickness of less than 100 nm (preferably less than 10 nm, more preferably less than 3 nm).

1A shows an anode current collector (eg, carbon-coated Al foil), an anode electrode (eg, a layer of activated carbon particles and conductive additives bound by a resin binder), a porous separator, a cathode electrode (eg For example, a schematic of a prior art supercapacitor, consisting of activated carbon particles and a layer of conductive additives, bonded by a resin binder, and a cathode current collector (eg, Al foil).
1B is a schematic diagram of a method for manufacturing a rope-shaped, flexible shape adaptive supercapacitor.
1C is four examples of procedures for manufacturing electrodes (rod-shaped anodes or cathodes) in a continuous automated manner.
1D is a schematic diagram of the process of the present invention for continuously producing an alkali metal-ion battery electrode.
2 is an electron microscope image of an isolated graphene sheet.
3A is an example of a conductive porous layer (metal grid / mesh and carbon nanofiber mat).
3B is an example of a conductive porous layer (graphene foam and carbon foam).
3C is an example of a conductive porous layer (graphite foam and Ni foam).
3D is an example of a conductive porous layer (Cu foam and stainless steel foam).
FIG. 4A shows a process commonly used to prepare exfoliated graphite, expanded graphite flakes (greater than 100 nm thick) and graphene sheets (less than 100 nm thick, more typically less than 10 nm thick, which may be as thin as 0.34 nm). Schematic diagram.
4B is a schematic diagram illustrating a manufacturing process of exfoliated graphite, expanded graphite flakes, and isolated graphene sheets.
FIG. 5 is a ragon diagram (weight and volumetric power density versus energy density) of a symmetric supercapacitor (EDLC) cell containing a reduced graphene oxide (RGO) sheet and an EMIMBF ₄ ionic liquid electrolyte as electrode active material. Data was obtained from both rope-type supercapacitors and prior art supercapacitors prepared by conventional electrode slurry coating for comparison.
FIG. 6 is a Ragon diagram (weight and volumetric power density vs. energy density) of a symmetric supercapacitor (EDLC) cell containing activated carbon (AC) particles and an organic liquid electrolyte as electrode active material.
FIG. 7A is a Ragon diagram (weight and volumetric power density versus energy density) of a lithium ion capacitor (LIC) cell containing a pure graphene sheet and a lithium salt-PC / DEC organic liquid electrolyte as electrode active material.
FIG. 7B is a Ragon plot (weight and volumetric power density versus energy density) of a sodium ion capacitor (NIC) cell containing a pure graphene sheet and sodium salt-PC / DEC organic liquid electrolyte as electrode active material.
FIG. 8 is a plot of cell-level weight and volumetric energy density over a range of achievable electrode diameters of AC-based EDLC supercapacitors made through conventional methods and methods of the present invention. Using the method of the present invention, there is no theoretical limit on the electrode diameter that can be achieved. Typically, the substantial electrode thickness is between 10 μm and 5,000 μm, more typically between 100 μm and 1,000 μm and most typically between 200 μm and 800 μm.
9 is an RGO-based EDLC supercapacitor (organic liquid electrolyte) prepared by a conventional method and a rope-shaped cell prepared by the method of the present invention (easily achieves an electrode tap density of about 0.75 g / cm ³ ). Is a plot of cell level weight and volume energy density over a range of electrode thicknesses that can be achieved.
10 is achievable electrode thickness ranges of pure graphene-based EDLC supercapacitors (organic liquid electrolyte) and rope-shaped cells (approximately 0.85 g / cm ³ electrode tab density) prepared by conventional methods. Plot of cell level weight and volume energy density for.
FIG. 11 shows achievable electrode thicknesses of pure graphene-based EDLC supercapacitors (ionic liquid electrolytes) prepared by conventional methods and rope-shaped cells (electrode tap density of approximately 0.85 g / cm ³ ) by the method of the present invention. Plot of cell level weight and volume energy density over range.
12 is a plot of cell level weight energy density versus active material ratio (active material weight / total cell weight) achievable for activated carbon based EDLC supercapacitors (using organic liquid electrolyte).
FIG. 13 is a plot of cell-level weight energy density versus achievable active material ratio (active material weight / total cell weight) in a supercapacitor cell for a series of two pure graphene-based EDLC supercapacitors, both with organic liquid electrolyte. .

The present invention relates to shape adaptive rope-like flexible supercapacitors which exhibit particularly high volumetric energy density and high weight energy density compared to conventional supercapacitors. Such supercapacitors may be EDLC supercapacitors (symmetric or asymmetrical), redox or pseudocapacitors, lithium ion capacitors (not lithium ion cells), or sodium ion capacitors (not sodium ion cells). Supercapacitors are based on aqueous electrolytes, non-aqueous or organic electrolytes, gel electrolytes, ionic liquid electrolytes, or mixtures of organic and ionic liquids.

As schematically illustrated in FIG. 1A, prior art supercapacitor cells typically comprise an anode current collector 202 (eg, 12 to 15 μm thick Al foil), an anode active material layer coated on the current collector ( 204 (containing an anode active material 232 such as activated carbon particles, and a conductive additive bonded by a resin binder such as PVDF), a porous separator 230, a cathode active material layer 208 (cathode active material such as activated carbon particles 234) , And conductive additives all bound by a resin binder, not shown), cathode current collector 206 (eg, Al foil), and anode active material layer 204 (also referred to simply as " anode layer "). And a liquid electrolyte disposed on both the cathode active material layer 208 (or simply " cathode layer "). The entire cell is cascaded in a protective housing, such as an envelope of thin plastic-aluminum foil laminate substrate. Prior art supercapacitor cells are typically manufactured by a method comprising the following steps:

a) The first step involves mixing particles of an anode active material (e.g. activated carbon), a conductive filler (e.g. graphite flakes), a resin binder (e.g. PVDF) in a solvent (e.g. NMP). To form an anode slurry. Individually, particles of cathode active material (e.g., activated carbon), conductive filler (e.g., acetylene black), resin binder (e.g., PVDF) are mixed and dispersed in a solvent (e.g., NMP) Form a cathode slurry.

b) The second step is coating this anode layer by coating the anode slurry on one or both of the primary surfaces of the anode current collector (eg Cu or Al foil) and vaporizing the solvent (eg NMP) Drying to form a dry anode electrode coated on Cu or Al foil. Likewise, the cathode slurry is coated and dried to form a dry cathode electrode coated on Al foil.

c) The third step involves laminating the anode / Al foil sheet, the porous separator layer, and the cathode / Al foil sheet together to form a three or five layer assembly, which is cut or cut and laminated to the desired size (one of the shape By way of example) forming a rectangular structure or winding it into a cylindrical cell structure.

d) The rectangular or cylindrical laminate structure is then placed in an aluminum-plastic laminate sheath or steel casing.

e) A liquid electrolyte is then injected into the laminated structure to produce a supercapacitor cell.

There are some serious problems associated with this conventional method and the resulting supercapacitor cell:

1) It is very difficult to produce electrode layers (anode layers or cathode layers) based on activated carbon thicker than 100 μm, and it is practically impossible or impractical to produce electrode layers thicker than 200 μm. There are several reasons for this:

a. 100 μm thick electrodes typically require 30 to 50 meter long heating zones in slurry coating equipment, which is too time consuming, too energy intensive and not cost-effective.

b. Thicker electrodes tend to peel and crack.

c. For some electrode active materials, such as graphene sheets, it was not possible to produce electrodes thicker than 50 μm continuously in actual manufacturing environments. Although some thicker electrodes are a concept that has been claimed in published or patent literature; These electrodes were made on a small scale in the laboratory. In a laboratory situation, new material could have been added to the layer repeatedly, possibly by incorporating the layer manually to increase the thickness of the electrode. However, even with such a manual procedure (difficult to mass produce), the resulting electrode is very brittle and brittle.

d. This problem is worse for graphene-based electrodes because repeated compaction leads to re-lamination of the graphene sheet, and thus to a significantly reduced specific surface area and reduced non-electrostatic capacity.

2) Using conventional methods, the actual mass feed of the electrode and the apparent density for the active material are too low, as depicted in FIG. 1A. In most cases, the active material mass supply (area density) of the electrode is significantly lower than 10 mg / cm ² , and the apparent bulk density or tap density of the active material is typically 0.75 g / cm, even for particles of relatively large activated carbon. Less than ³ (more typically less than 0.5 g / cm ³ , most typically less than 0.3 g / cm ³ ). Additionally, there are other inert materials (eg, conductive additives and resin binders) that add additional weight and volume to the electrode without contributing to cell capacity. Such low area density and low volume density result in relatively low volumetric capacity and low volumetric energy density.

3) The conventional process requires dispersing the electrode active material (anode active material and cathode active material) in a liquid solvent (for example, NMP) to prepare a slurry, and when coating the current collector surface, the liquid solvent dries the electrode layer. To be removed. When the anode layer and the cathode layer are laminated together with the separator layer and packaged in a housing to prepare a supercapacitor cell, a liquid electrolyte is injected into the cell. In practice, the two electrodes are wetted, then the electrodes are dried and finally wet again. This wet-dry-wet process does not seem to be a good process at all.

4) NMP is not an environmentally friendly solvent; It is known to cause potentially birth defects.

5) Current supercapacitors (eg symmetric supercapacitors or electric double layer capacitors, EDLCs) still suffer from relatively low weight energy density and low volumetric energy density. Commercially available EDLCs show a weight energy density of approximately 6 Wh / kg, and no experimental EDLC cells show higher energy densities than 10 Wh / kg (based on total cell weight) at room temperature. . Experimental supercapacitors exhibit large volume electrode capacities (100-200 F / cm ³ in most cases) at the electrode level (not at the cell level), but their typical mass feeds of active materials below 1 mg / cm ² , Tap densities of less than 0.1 g / cm ^-3 , and electrode thicknesses of several tens of micrometers or less remain significantly lower than those used in most commercially available electrochemical capacitors, the energy storage device being the cell (device) weight It has relatively low area and volume capacity and low volume energy density.

In the literature, the energy density data reported based on the active material weight alone or on the electrode weight cannot be converted directly to the energy density of the actual supercapacitor cell or device. The weight of "overhead weight" or other device components (binder, conductive additive, current collector, separator, electrolyte, and packaging) should also be considered. In conventional manufacturing methods, the result is that the ratio of active material is less than 30% by weight of the total cell weight (in some cases, for example less than 15% for graphene-based active materials).

The present invention provides a method of making a shape adaptive flexible supercapacitor having a rope type, high active material mass feed, low overhead weight and volume, high weight energy density, and high bulk energy density. In addition, the manufacturing cost of the supercapacitors produced by the process of the present invention can be significantly lower than those by conventional methods and are much better environmentally.

In one embodiment of the present invention, as illustrated in FIG. 1C, the rope-type supercapacitor of the present invention containing a braided or yarn-shaped electrode is characterized in that it is smaller than the pore size of the first electrode active material (eg, the porous rod). Electrically conductive porous rod (eg, carbon foam, graphene foam, metal nano) having pores partially or fully supplied with a mixture of activated carbon particles or an isolated / separated graphene sheet having a size and a first electrolyte Wire mat, etc.), which may include a first step of supplying the first electrode 11. Conductive additives or resin binders may optionally be added to the mixture, but this is not necessary or even undesirable. The first electrode 11 may optionally contain an end portion 13 of the active material member electrolyte member, which may serve as a terminal tab for connecting a supercapacitor to an external load. The first electrode may have a cross section of any shape, for example round, rectangular, elliptical, square, hexagonal, hollow, or irregularly shaped.

Alternatively, in the first step, the first electrode comprises a conductive rod (not a porous foam) and the first mixture is coated or deposited on the surface of the conductive rod. This rod can be as simple as a metal wire, conductive polymer fiber or yarn, carbon or graphite fiber or yarn, or a plurality of thin wires, fibers, or yarns. In this state, however, the second electrode must comprise a porous foam structure.

The second step is to wrap the first electrode 11 with a thin porous separator 15 (e.g., porous plastic film, paper, fiber mat, nonwoven, glass fiber cloth, etc.) permeable to ions in the electrolyte, or Casing. This step can be as simple as wrapping the first electrode entirely with a thin, porous plastic tape, or slightly more than one wheel, or spirally. The main purpose is to electrically isolate the anode and cathode to prevent internal short circuits. The porous separator layer can simply be deposited around the first electrode by spraying, printing, coating, dip casting, or the like.

The third step includes preparing a second electrode 17 comprising a mixture of a second active material and a second electrolyte, and optionally a conductive additive or resin binder (not required, but not preferred). The second electrode 17 may optionally contain an end portion of the active material member electrolyte member, which may serve as a terminal tab for connecting to an external load. The second electrode may optionally be cascaded or enclosed by, but preferably by the porous separator layer 18.

This second electrode, with or without a casing porous separator layer, is made of double-ply twisted yarn or braid in combination with the first electrode using a braiding or yarn-making procedure. If the first electrode is an anode, the second electrode is a cathode; The reverse is also possible. The yarn or braid may contain one single cathode or multiple anodes in combination with multiple cathodes (ie, multiple filaments or rods each containing an anode active material and an electrolyte). The yarn or braid may contain a plurality of cathodes (ie, a plurality of filaments or rods each containing a cathode active material and an electrolyte) in combination with one single anode or a plurality of anode filaments. As a final step, this braid or yarn structure is cased or protected by an electrically insulated protective casing or sheath 19 (eg a plastic sheath or rubber shell).

It may be noted that some additional electrolyte may be incorporated between the n-ply braid / yarn (n ≧ 2) and the protective sheath. However, this is not necessary because all electrode rods or filaments already contain active materials and electrolytes in their pores.

In some embodiments, one of the electrodes comprises a porous rod having pores for receiving the active material-electrolyte mixture, and at least one of the electrodes has a non-porous rod (filament, fiber having an active material-electrolyte mixture coated on its surface) , Wire, etc.).

The electrodes of this supercapacitor can be produced in a roll-to-roll manner. In one embodiment, as illustrated in FIGS. 1C and 1D, the method of the present invention provides an electrically conductive porous rod / filament (eg, 304, 310, 322, or 330) from a feeder roller (not shown). Continuously feeding into the active material impregnation region, wherein the wetted active material-electrolyte mixture (eg, (306a, 306b,) containing an electrode active material (eg, activated carbon particles and / or graphene sheets) and an electrolyte Slurries, suspensions, or gel-like agglomerates, such as 312a, 312b) are well mixed together and optional conductive additives are transferred to the porous surface of the porous layer (eg, in schematic A and schematic B, respectively, in FIG. 1C). (304 or 310)). Using schematic A as an example, the wetted active material-electrolyte mixture 306a, 306b is forcibly impregnated into the porous layer from both sides using one or two pairs of rollers 302a, 302b, 302c and 302d An active electrode 308 (anode or cathode) is formed. The conductive porous layer contains interconnected electron-conducting pathways and preferably at least 70% by volume (preferably greater than 80%, more preferably greater than 90%) pores. Foam rods / filaments typically have a pore volume of 50% to approximately 99%.

In schematic B, two feeder rollers 316a and 316b are used to successively release two protective films 314a and 314b supporting the wet active material-electrolyte mixture rods / filaments 312a and 312b. These wet active material-electrolyte mixture rods / filaments 312a, 312b may be protected (supported) films 314a, 314b using a variety of procedures (eg, those well known in the art, such as printing, spraying, casting, coating, etc.). Can be delivered. As the conductive porous layer 110 moves through the gap between two sets of rollers 318a, 318b, 318c, 318d, the wet active material-electrolyte mixture is impregnated into the pores of the porous rod or filament 310, The active material electrode 320 (anode or cathode electrode) which is tentatively covered by the two protective films 314a and 314b is formed.

As another example of schematic C, two spraying devices 324a, 324b are used to distribute the wetted active material-electrolyte mixture 325a, 325b to two opposing porous surfaces of the conductive porous layer 322. The wet active material-electrolyte mixture is forcibly impregnated the porous rod from both sides using a pair or two pairs of rollers to form the impregnated active electrode 326 (anode or cathode). Likewise, in schematic D, two spraying devices 332a, 332b are used to distribute the wetted active material-electrolyte mixture 333a, 333b to the porous surface of the conductive porous rod 330. The wet active material-electrolyte mixture is forcibly impregnated the porous rod using a pair or two pairs of rollers to form an impregnated active electrode 338 (anode or cathode).

As another example, as illustrated in schematic E of FIG. 1D, the electrode manufacturing process begins by continuously feeding the conductive porous rod 356 from the feed roller 340. Porous rod 356 is guided by roller 342 and immersed in wet active material-electrolyte mixture material 346 (slurry, suspension, gel, etc.) in vessel 344. As the active material-electrolyte mixture moves toward roller 342b, it begins to impregnate the pores of the porous rod 356 and is fed out of the container into the gap between the two rollers 348a, 348b. Two protective films 350a and 350b are simultaneously supplied from two respective rollers 352a and 352b, covering the impregnated porous rod 354, which is continuously recovered on the rotating drum (winding roller 355). Can be. This process can be applied to both anode and cathode electrodes.

The resulting electrode rod or filament (anode or cathode electrode) may have a thickness or diameter of 100 nm to several centimeters (or more, if desired). In the case of micro cables (eg, as flexible power sources for microelectronic devices), the thickness or diameter of the electrodes is between 100 nm and 100 μm, more typically between 1 μm and 50 μm, most typically between 10 μm and 30 μm. to be. In the case of macroscopic shape adaptive flexible cable cells (eg for use in confined spaces of electric vehicles (EVs)), the electrodes are typically and preferably at least 100 μm (preferably greater than 200 μm, more preferably More than 300 μm, more preferably more than 400 μm, even more preferably more than 500 μm, more than 600 μm, or even more than 1,000 μm) and there is no theoretical limit to the electrode thickness.

The above are only a few examples to illustrate how the shape-adaptive rope type flexible alkali metal cell of the present invention can be manufactured. These examples should not be used to limit the scope of the present invention.

The electrically conductive porous rods or filaments may be metal foams, metal webs or screens, perforated metal sheet-based structures, metal fiber mats, metal nanowire mats, conductive polymer nanofiber mats, conductive polymer foams, conductive polymer-coated fiber foams, carbon Selected from foam, graphite foam, carbon aerogel, carbon zero gel, graphene airgel, graphene foam, graphene oxide foam, reduced graphene oxide foam, carbon fiber foam, graphite fiber foam, exfoliated graphite foam, or combinations thereof Can be. Porous rods or filaments must be made of electrically conductive materials (such as porous mats, screens / grids, nonwovens, foams, etc.) such as carbon, graphite, metals, metal-coated fibers, conductive polymers, or conductive polymer-coated fibers. . Examples of conductive porous layers are shown in FIGS. 3A, 3B, 3C, and 3D. The porosity level should be at least 50% by volume, preferably greater than 70% by volume, more preferably greater than 90% by volume and most preferably greater than 95% by volume. The backbone of the foam or foam wall forms the entire 3D network of electron-conducting paths.

It may be noted that the graphene or graphene oxide material in the graphene foam, graphene oxide foam, or graphene airgel foam structure constitutes the pore wall of the foam. Such graphene or graphene oxide materials of this shape do not contain isolated or separated graphene sheets. Such graphene or graphene oxide material in the foam is not part of the active material-electrolyte mixture impregnated into the pores of the foam. This mixture may contain activated carbon particles or isolated graphene sheets that are not part of the foam structure. These activated carbon particles or isolated graphene sheets are primary electrode active materials of supercapacitors.

These foam structures can be readily produced in any cross-sectional shape. They can also be very flexible; Typically, nonmetallic foams are more flexible than metal foams. However, metal nanofibers can be made into highly flexible foams. Since the electrolyte is in a liquid or gel state, the resulting cable cell can be very flexible and can be made to essentially conform to any unique shape. Even when the salt concentration in the liquid solvent is high (for example 2.5 M to 15 M), the foamed structure containing the electrolyte inside the pores can still be deformed, bent, twisted and matched to the unusual shape. Can be.

In some embodiments, the electrically conductive porous rod in the first or second electrode is a conductive polymer fiber mat, a carbon / graphite fiber mat, a fiber tow with pores between the fibers, a conductive fiber knit structure or a plurality of fibers or It contains a nonwoven structure having pores. Many of these fibers may contain conductive polymer fibers, metal coated fibers, carbon coated polymer fibers, carbon fibers, or graphite fibers.

Preferably, substantially all pores in the original conductive porous rod or filament are filled with an electrode active material (anode or cathode), an electrolyte, and an optional conductive additive (no binder resin required). Because of the large amount of pores present (more typically 70-99% or preferably more typically 85% -99%) relative to the pore walls or conductive paths (1-30%), very little space is wasted (“Wasted” means not occupied by the electrode active material and the electrolyte), resulting in a high ratio of electrode active material-electrolyte mixture (high active material feed mass).

In this supercapacitor electrode configuration (e.g., Figure 1b), there are pore walls everywhere throughout the entire electrode structure, so that the electrons have a short distance (on average half the pore size, e.g., before being collected by the pore wall). Just move in nanometers or micrometers (conductive foam acts as a current collector). These pore walls form a 3D network of interconnected electron transfer paths with minimal resistance. In addition, at each anode electrode or cathode electrode, all electrode active material particles are pre-dispersed in the liquid electrolyte (no wettability problem), which is common for electrodes made by conventional processes of wet coating, drying, packing, and electrolyte injection. Eliminate the presence of dry pockets that exist. Thus, the process of the present invention brings an unexpected advantage over the conventional supercapacitor cell manufacturing process.

In a preferred embodiment, the graphene electrode active material (instead of activated carbon) is pure graphene, graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, Nitrogenated graphene, chemically functionalized graphene, or a combination thereof. Starting graphite materials for the production of any one of the graphene materials are natural graphite, artificial graphite, mesophase carbon, mesophase pitch, mesocarbon microbeads, soft carbon, hard carbon, coke, carbon fiber, carbon Nanofibers, carbon nanotubes, or combinations thereof.

The invention also provides a lithium ion capacitor (LIC) or sodium ion capacitor (NIC), wherein at least one of the two electrodes in the cell is produced by the method of the invention. More preferably, both anode and cathode electrodes for the LIC or NIC of the invention are prepared by the method of the invention described above. This method of the present invention comprises the steps of (A) continuously feeding the electrically conductive porous rod / filament into the anode material impregnation region, wherein the conductive porous rod / filament has a porous surface and is interconnected electron-conducting pathway, preferably Contains at least 70% by volume pores; And (B) impregnating a wet anode active material-electrolyte mixture from at least one porous surface into an electrically conductive porous rod to form an electrode. For example, a wet anode active material mixture may be prelithiated or presodiumated of graphite particles, carbon particles, Si nanoparticles, Sn nanoparticles, or any other anode active material commonly used for lithium ion batteries or sodium ion batteries. An anode active material and a liquid electrolyte which are preferably selected from the forms. These anode active materials can be prepared in the form of fine particles, wherein the plurality of particles together with the conductive additive particles are easily mixed with the liquid electrolyte to form a wet anode active material mixture (e.g. in the form of a slurry) for impregnation into the conductive porous layer. Can be formed. Corresponding cathodes may contain active materials of the EDLC type (eg, activated carbon or isolated graphene sheets), with or without redox pair partner materials (eg, inherently conductive conjugate polymers or transition metal oxides). Can be.

In lithium ion capacitors (LIC), the anode active material includes (a) prelithiated particles of natural graphite, artificial graphite, mesocarbon microbeads (MCMB), and carbon; (b) silicon (Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), zinc (Zn), aluminum (Al), nickel (Ni), cobalt ( Prelithiated particles or coatings of Co), manganese (Mn), titanium (Ti), iron (Fe), and cadmium (Cd); (c) stoichiometric or nonstoichiometric prelithiated alloys or intermetallic compounds of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, or Cd with other elements; (d) prelithiated oxides, carbides, nitrides, sulfides of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Fe, Ni, Co, Ti, Mn, or Cd, and mixtures or composites thereof; Phosphides, selenides, and tellurides; And (e) prelithiated graphene sheets; And combinations thereof. Prelithiation can be accomplished electrochemically using small mass graphene sheets as working electrodes and lithium metal as counter electrodes. Prelithiation can also be achieved by adding lithium powder or chips into the liquid electrolyte along with the anode active material (eg Si particles) and conductive additive particles.

In sodium ion capacitors, the anode active material is a petroleum coke, carbon black, amorphous carbon, activated carbon, hard carbon, soft carbon, template carbon, hollow carbon nanowires, hollow carbon spheres, or pre-sodiumated forms of titanate, or NaTi ₂ ( PO ₄ ) ₃ , Na ₂ Ti ₃ O ₇ , Na ₂ C ₈ H ₄ O ₄ , Na ₂ TP, Na _x TiO ₂ (x = 0.2 to 1.0), Na ₂ C ₈ H ₄ O ₄ , carboxylate Substance, C ₈ H ₄ Na ₂ O ₄ , C ₈ H ₆ O ₄ , C ₈ H ₅ NaO ₄ , C ₈ Na ₂ F ₄ O ₄ , C ₁₀ H ₂ Na ₄ O ₈ , C ₁₄ H ₄ O ₆ , C ₁₄ H ₄ Na ₄ O ₈ , or a combination thereof.

In sodium ion capacitors, the anode active material contains a sodium insertion compound selected from the following group of materials: (a) sodium doped silicon (Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb) ), Bismuth (Bi), zinc (Zn), aluminum (Al), titanium (Ti), cobalt (Co), nickel (Ni), manganese (Mn), cadmium (Cd), and mixtures thereof; (b) sodium-containing alloys or intermetallic compounds of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Ti, Co, Ni, Mn, Cd, and mixtures thereof; (c) Sodium-containing oxides, carbides, nitrides, sulfides, phosphides, seleniums of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Fe, Ti, Co, Ni, Mn, Cd, and mixtures or composites thereof Cargo, telluride, or antimony cargo; (d) sodium salts; And (e) graphene sheets preloaded with sodium or potassium. Pre-sodiumation can be accomplished electrochemically by using small mass graphene sheets as working electrodes and sodium metal as counter electrodes. Pre-sodiumation may also be achieved by adding lithium powder or chips into the liquid electrolyte along with the anode active material (eg Sn particles) and conductive additive particles.

Bulk natural graphite is a 3-D graphite material having each graphite particle composed of a plurality of grains (graphite single crystal or microcrystal) having grain boundaries (amorphous or missing regions) that separate the boundaries of neighboring graphite single crystals. Each grain consists of a plurality of graphene faces oriented parallel to each other. In graphite microcrystals, the graphene plane consists of carbon atoms occupying a two-dimensional hexagonal lattice. In certain grains or single crystals, the graphene faces are stacked and bonded through van der Waals forces in the crystallographic c -direction (perpendicular to the graphene plane or base plane). All graphene faces in one grain are parallel to each other, but typically the graphene faces in one grain and the graphene faces in adjacent grains are inclined in different orientations. That is, the orientations of the various crystal grains in the graphite particles are usually different from each other.

If the interplanetary van der Waals forces can be overcome, the graphene plane, which is a component of the graphite microcrystals in natural or artificial graphite particles, is stripped and extracted or isolated to obtain individual graphene sheets of hexagonal carbon atoms, which are monoatomic thick. Can be. Individual graphene faces of carbon atoms isolated are generally referred to as single layer graphene. Stacks of multiple graphene planes coupled through van der Waals forces in the thickness direction with a graphene interplanar spacing of approximately 0.3354 nm are generally referred to as multilayer graphene. Multilayer graphene plates have up to 300 layers of graphene faces (less than 100 nm thick), but typically have up to 30 graphene faces (less than 10 nm thick), and even more typically up to 20 graphene faces. It has a fin face (less than 7 nm thick), most commonly no more than 10 graphene faces (commonly referred to in science as the few-layer graphene). Single layer graphene and multilayer graphene sheets are collectively referred to as " nanographene plates " (NGP) as shown in FIG. Graphene sheets / plates (collectively NGP) are a new class of carbon nanomaterials (2-D nanocarbons) distinguished from 0-D fullerenes, 1-D CNTs or CNFs, and 3-D graphite. To define the claims and as generally understood in the art, the graphene material (isolated graphene sheet) is not (and does not include) carbon nanotubes (CNT) or carbon nanofibers (CNF). .

The research group played a pioneering role in the development of graphene materials and related manufacturing processes in the early years of 2002: (1) B. Z. Jang and W. C. Huang, "Nano-scaled Graphene Plates," U.S. Pat. No. 7,071,258 (07/04/2006), application submitted on October 21, 2002; (2) B. Z. Jang, et al. "Process for Producing Nano-scaled Graphene Plates," U.S. Patent Application No. 10 / 858,814 (06/03/2004); And (3) B. Z. Jang, A. Zhamu, and J. Guo, "Process for Producing Nano-scaled Platelets and Nanocomposite," US Pat. Application No. 11 / 509,424 (08/25/2006).

In one process, the graphene material, as illustrated in FIGS. 4A and 4B (Schematic), inserts natural graphite particles with a strong acid and / or oxidant to incorporate graphite intercalation compounds (GIC) or graphite oxides (GO). Obtained by The presence of species or functional groups in the interstitial spaces between the graphene planes in GIC or GO increases the gap between graphenes ( d _{002 as} measured by X-ray diffraction), otherwise along the c axis direction Significantly reduces the van der Waals forces that bind the graphene faces together. GIC or GO is in most cases produced by immersing natural graphite powder (100 in FIG. 4B) in a mixture of sulfuric acid, nitric acid (oxidant), and another oxidant (eg, potassium permanganate or sodium perchlorate). If oxidant is present during the insertion process, the resulting GIC 102 is actually some type of graphite oxide (GO) particles. This GIC or GO is then repeatedly washed and washed in water to remove excess acid, resulting in a graphite oxide suspension or dispersion containing visually identifiable discrete graphite oxide particles dispersed in water. To prepare the graphene material, after this cleaning step, one of the two processing paths outlined below can be followed.

범위의 온도에 대략 30초 내지 2분 동안 노출시키면, GIC는 30 내지 300배로 급속한 부피 팽창을 겪어, 박리되었지만 크게 분리되지 않은 상호 연결된 상태의 흑연 플레이크의 집합체인 "흑연 웜(graphite worm)"(104)을 형성한다.Path 1 includes removing water from the suspension to obtain "expandable graphite" which is essentially a large amount of dried GIC or dried graphite oxide particles. 800 to 1,050 for expandable graphite

When exposed to temperatures in the range of approximately 30 seconds to 2 minutes, the GIC undergoes a rapid volume expansion of 30 to 300 times, causing the "graphite worm", which is a collection of interconnected graphite flakes that have been peeled off but not largely separated ( 104).

In path 1A, these graphite worms (a network of exfoliated graphite or “interconnected / unseparated graphite flakes”) are recompressed and are typically flexible graphite having a thickness ranging from 0.1 mm (100 μm) to 0.5 mm (500 μm) Sheet or foil 106 may be obtained. Alternatively, low intensity air mills or shears may be used for the purpose of producing so-called "expanded graphite flakes" 108 (hence by definition not nanomaterials) containing graphite flakes or plates thicker than 100 nm. You can choose to simply destroy the graphite worm.

In Route 1B, as disclosed in Applicant's U.S. Application No. 10 / 858,814 (June 3, 2004), exfoliated graphite is used (eg, using an ultrasonicator, high shear mixer, high intensity air jet mill, or high energy ball mill). ) High strength mechanical shearing to form separate monolayer and multilayer graphene sheets (collectively NGP 112). Single layer graphene may be as thin as 0.34 nm, while multilayer graphene may have a thickness of less than 100 nm, but more typically less than 10 nm (generally referred to as hydrophobic graphene). Papermaking processes can be used to make a number of graphene sheets or plates into NGP paper sheets. This NGP paper sheet is an example of a porous graphene structure layer used in the process of the present invention.

Path 2 involves sonicating the graphite oxide suspension (eg, graphite oxide particles dispersed in water) for the purpose of separating / isolating the individual graphene oxide sheets from the graphite oxide particles. This is based on the concept that the intergraphene interplanar separation increased from 0.3354 nm in natural graphite to 0.6 to 1.1 nm in highly oxidized graphite oxide, significantly weakening the van der Waals forces that bond adjacent surfaces to each other. The ultrasonic power may be sufficient to further separate the graphene face sheet to form a fully separated, isolated, or discrete graphene oxide (GO) sheet. These graphene oxide sheets are then chemically or thermally reduced, typically with an oxygen content of 0.001% to 10% by weight, more typically 0.01% to 5% by weight, most typically less than 2% by weight. A "reduced graphene oxide" (RGO) with oxygen can be obtained.

In order to define the claims of the present application, NGP or graphene materials are single and multilayer (typically less than 10 layers) pure graphene, graphene oxide, reduced graphene oxide (RGO), graphene fluoride Diacids of graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, chemically functionalized graphene, doped (eg doped with B or N) graphene Sheet / plate. Pure graphene has essentially 0% oxygen. RGO typically has an oxygen content of 0.001% to 5% by weight. Graphene oxide (including RGO) may have from 0.001% to 50% by weight of oxygen. In addition to pure graphene, all graphene materials have from 0.001% to 50% by weight of non-carbon elements (eg, O, H, N, B, F, Cl, Br, I, etc.). Such materials are referred to herein as non-pure graphene materials.

Pure graphene in smaller discrete graphene sheets (typically 0.3 μm to 10 μm) can be produced by supercritical fluid exfoliation of graphite particles or direct sonication (also known as liquid exfoliation or preparation). Such processes are well known in the art.

Graphene oxide (GO) is the desired temperature of a powder or filament of a starting graphite material (eg a natural graphite powder) in an oxidizing liquid medium (eg, a mixture of sulfuric acid, nitric acid, and potassium permanganate) in a reaction vessel. Can be obtained by soaking for a period of time (typically 0.5 to 96 hours depending on the nature of the starting material and the type of oxidant used). As mentioned above, the resulting graphite oxide particles may then be subjected to thermal peeling or ultrasonic-induced peeling to produce an isolated GO sheet. These GO sheets can then be converted to various graphene materials by substituting -OH groups with other chemical groups (eg -Br, NH _2, etc.).

Graphene fluoride or graphene fluoride is used herein as an example of a group of halogenated graphene materials. There are two different approaches for preparing graphene fluoride. (1) Fluorination of presynthesized graphene: This approach involves treating graphene prepared by mechanical exfoliation or CVD growth with a fluorinating agent, such as XeF ₂ , or an F-based plasma; (2) Peeling of the multilayer graphite fluoride: Both mechanical peeling and liquid phase peeling of the graphite fluoride can be easily achieved.

At high temperatures, F ₂ interacts with graphite to form covalent graphite fluorides (CF) _n or (C ₂ F) _n , whereas at low temperatures, graphite intercalation compounds (GIC) C _x F (2 ≦ x ≦ 24) are formed. . Since the carbon atom at (CF) _n is sp3-hybridized, the fluorocarbon layer is a waveform consisting of trans-linked cyclohexane chains. In (C ₂ F) _n only half of the C atoms are fluorinated and all pairs of adjacent carbon sheets are connected to each other by CC covalent bonds. A systematic study of the fluorination reaction indicates that the resulting F / C ratio is highly dependent on the fluorination temperature, the partial pressure of fluorine in the fluorination gas, and the physical properties of the graphite precursor (including degree of graphitization, particle size and specific surface area). appear. Most available literature includes fluorination with F ₂ gas (sometimes in the presence of fluoride), but other fluorides may be used in addition to fluorine (F ₂ ).

In order to peel off the layered precursor material in the state of individual layers or minority layers, it is necessary to overcome the attraction between adjacent layers and to further stabilize these layers. This can be achieved by covalent modification of the graphene surface by functional groups or by non-covalent modification using specific solvents, surfactants, polymers, or donor-receptor aromatic molecules. The liquid phase stripping process includes sonication of graphite fluoride in a liquid medium.

에서 암모니아에 노출시켜 수행될 수 있다. 질소화 그래핀은 또한 저온에서 수열법에 의해, 예를 들어, GO와 암모니아를 오토클레이브에서 밀봉한 다음 온도를 150 내지 250

로 증가시켜 형성될 수 있다. 질소 도핑된 그래핀의 합성을 위한 기타 다른 방법은 그래핀에 대한 질소 플라즈마 처리, 암모니아의 존재 하에서의 흑연 전극 간의 아크-방전, CVD 조건 하에서의 그래핀 산화물의 암모니아 분해, 및 상이한 온도에서의 그래핀 산화물과 요소의 수열 처리를 포함한다.Nitriding of graphene can lead to high temperature (200 to 400)

It can be carried out by exposure to ammonia at. Nitrogenated graphene can also be hydrothermally sealed at low temperatures, for example by sealing GO and ammonia in an autoclave and then raising the temperature from 150 to 250.

It can be formed by increasing. Other methods for the synthesis of nitrogen doped graphene include nitrogen plasma treatment of graphene, arc-discharge between graphite electrodes in the presence of ammonia, ammonia decomposition of graphene oxide under CVD conditions, and graphene oxide at different temperatures. And hydrothermal treatment of urea.

The foregoing features are further described and described in detail as follows: As illustrated in FIG. 4B, the graphite particles (eg, 100) are typically composed of many graphite microcrystals or grains. Graphite microcrystals consist of a layered plane of hexagonal networks of carbon atoms. These layered planes of hexagonally arranged carbon atoms are substantially flat and are oriented or aligned such that they are substantially parallel and equidistant from one another in certain microcrystals. The hexagonal carbon atoms layer, generally referred to as graphene layer or base surface, is weakly bound to each other in the thickness direction (crystallographic c- axis direction) by weak van der Waals forces, and the group of graphene layers is microcrystalline. Are arranged. Graphite microcrystalline structures are generally characterized in terms of two axes or directions, namely the c-axis direction and the a- axis (or b- axis) direction. The c axis is in a direction perpendicular to the base surface. The a or b axis is in a direction parallel to the base plane (perpendicular to the c axis direction).

The higher order graphite particles are crystallites of considerable size with a length L _a along the a -axis direction crystallographically, a width L _b along the b -axis direction crystallographically, and a thickness L _c along the crystallographic c -axis direction. Can be made with a crystal. The constituent graphene faces of the microcrystals are highly aligned or oriented with respect to each other, so that these anisotropic structures give rise to many highly directional properties. For example, the thermal and electrical conductivity of microcrystals is large along the plane direction ( a- or b -axis direction), but relatively low in the vertical direction ( c -axis). As illustrated in the upper left portion of FIG. 4B, different microcrystals in the graphite particles are typically oriented in different directions, and thus the properties of the multi-microcrystalline graphite particles are the direction average values of all component microcrystals.

Due to the weak van der Waals forces that bond the parallel graphene layers, the natural graphite is treated to allow the graphene interlayer spacing to be significantly widened to provide significant expansion in the c- axis direction, thereby substantially maintaining the layered properties of the carbon layer. Expanded graphite structures can be formed. Processes for producing flexible graphite are well known in the art. Generally, flakes of natural graphite (eg, 100 in FIG. 4B) are intercalated in an acidic solution to produce graphite intercalation compounds (GIC, 102). GIC is washed, dried and then exfoliated by exposure to high temperatures for a short time. This causes the flakes to expand or delaminate up to 80 to 300 times their original dimensions in the c- axis direction of the graphite. The exfoliated graphite flakes are generally referred to as graphite worms 104 because they are worm-shaped in appearance. Such largely expanded graphite flake worms are agglomerated or integrated sheets of expanded graphite, such as webs, papers, strips, tapes, foils, which have a density of typically about 0.04 to 2.0 g / cm ³ in most applications. , Mat, or the like (commonly referred to as "flexible graphite" 106), without the use of a binder.

Acids such as sulfuric acid are not the only type of intercalating agent (insert) that penetrates into the spaces between the graphene faces to obtain GIC. Many other types of intercalating agents, such as alkali metals (Li, K, Na, Cs, and their alloys or eutectics) can be used to insert graphite into stage 1, stage 2, stage 3, and the like. have. Stage n means that there is one layer of insert for every n graphene faces. For example, a stage-1 potassium-inserted GIC means that there is one K layer for every graphene face, or the G / K / G / K / G / KG ... sequence (G is the graphene face and K Is a potassium atom plane), meaning that one layer of K atoms can be found between two adjacent graphene planes. Stage-2 GIC will have the order GG / K / GG / K / GG / K / GG ... Stage-3 GIC will have the order GGG / K / GGG / K / GGG ... . These GICs may then be contacted with water or a water-alcohol mixture to produce exfoliated graphite and / or separated / isolated graphene sheets.

The exfoliated graphite worms are subjected to high-strength mechanical shear / separation using high-intensity air jet mills, high-intensity ball mills, or ultrasonic devices so that all graphene plates are thinner than 100 nm, mostly thinner than 10 nm, and in many cases single layer graphene. Nanographene plates (NGP) can be produced (also illustrated as 112 in FIG. 4B). NGP consists of a graphene sheet or a plurality of graphene sheets, each sheet having a two-dimensional hexagonal structure of carbon atoms. Large quantities of several NGPs (including single and / or minor layer graphene or discrete sheets / plates of graphene oxide) can be made into graphene films / paper (114 in FIG. 4B) using a film or paper making process. have. Alternatively, using low intensity shear, the graphite worms tend to separate into so-called expanded graphite flakes (108 in FIG. 4B) having a thickness greater than 100 nm. These flakes can be formed of graphite paper or mat 106 using a paper or mat manufacturing process, with or without a resin binder.

Although individual graphene sheets have a particularly high specific surface area, graphene sheets tend to re-laminate together or overlap each other, resulting in a sharp reduction in non-electrostatic capacity due to a significant reduction in the specific surface area accessible by the electrolyte. Is reduced. This re-lamination tendency is especially severe during the supercapacitor cell electrode production process. In this process, together with other conductive additives and resin binders (e.g. PVDF), the graphene sheets are dispersed in a solvent (usually NMP) to form a slurry, which is then subjected to a solid current collector (e.g. Al On the surface of the foil). The solvent is then removed (vaporized) to form a dry layer of the active material electrode, which is fed through a pair of rollers in the compactor to harden the electrode layer. These drying and pressing procedures lead to severe graphene relamination. In many scientific reports, it has been found that the graphene sheet in its original powder form exhibits an exceptionally high specific surface area, but the resulting electrode only unexpectedly exhibits a lower non-electrostatic capacity. Theoretically, the maximum non-electromagnetic capacity of single layer graphene supercapacitors is as high as 550 F / g (based on EDLC structure, no redox pair or pseudocapacitance), but the experimentally achieved values are only 90 to 170 F / was in the range of g. This is a longstanding problem in the field of supercapacitors.

The present invention provides a very innovative and clear process to overcome this graphene sheet relamination problem. The process of the present invention completely eliminates the need to undergo slurry coating, drying, and compression procedures. Instead of forming a slurry containing an environmentally undesirable solvent (ie, NMP), the method involves dispersing the graphene sheet in a liquid electrolyte to form a slurry of the electrode active material-liquid electrolyte mixture. This mixture slurry is then injected into the pores of the current collector based on the conductive foam; Subsequent drying and compaction is not required, and there is very little or no chance that the graphene sheets will relaminate together. In addition, the graphene sheets are already predispersed in the liquid electrolyte, which essentially means that all graphene surfaces are naturally accessible to the electrolyte, leaving no “dry pockets”. This method also enables the inventors to pack the graphene sheets (with electrolyte in between) in a highly dense manner, which leads to unexpectedly high electrode active material tap densities.

The graphene sheets used in the aforementioned methods, separately or in combination, can be treated as follows:

(a) Chemical functionalization or doping with atoms, ions, or molecular species. Useful surface functionalities can include quinones, hydroquinones, quaternized aromatic amines, mercaptans, or disulfides. This class of functional groups can impart pseudocapacitance to graphene-based supercapacitors.

(b) coated or grafted with an inherently conductive polymer (conductive polymers such as polyacetylene, polypyrrole, polyaniline, polythiophene, and derivatives thereof are good choices for use in the present invention); These treatments are intended to further increase capacitance values through pseudocapacitive effects such as redox reactions.

(c) transition metal oxides or sulfides, such as RuO ₂ , TiO ₂ , MnO ₂ , Cr ₂ O ₃ , and Co, for the purpose of forming redox pairs using graphene sheets to impart similar capacitances to the electrodes. Deposition with ₂ O ₃ ; And

(d) Activation treatments (similar to the activation of carbon black materials) create additional surfaces and possibly impart chemical functionalities to these surfaces. The activation treatment can be accomplished through CO ₂ physical activation, KOH chemical activation, or exposure to nitric acid, fluorine, or ammonia plasma.

The inventors have found that a wide variety of two-dimensional (2D) inorganic materials can be used in the supercapacitors of the invention produced by the active material-electrolyte mixture impregnation process of the invention. Layered materials represent various sources of 2D systems that can exhibit unexpected electronic properties and high specific surface areas that are important in supercapacitor applications. Graphite is the best known layered material, but the transition metal dichalcogenide (TMD), transition metal oxide (TMO), and a wide variety of other compounds such as BN, Bi ₂ Te ₃ , and Bi ₂ Se ₃ , also possible 2D materials It is a source.

Non-graphene 2D nanomaterials, monolayers or hydrophobic layers (up to 20 layers) can be prepared by several methods: mechanical cutting, laser ablation (eg, ablation of TMD to monolayer using laser pulses), Liquid phase separation, and thin film techniques such as PVD (eg sputtering), evaporation, vapor phase epitaxy, liquid phase epitaxy, chemical vapor phase epitaxy, molecular beam epitaxy (MBE), atomic layer epitaxy (ALE), and their Synthesis by Plasma-Assisted Form.

The inventors surprisingly find that when most of these inorganic materials are 2D nanodisk, nanoplate, nanobelt, or nanoribbon shapes, these inorganic materials are usually electrically nonconductive and thus are not considered candidate supercapacitor electrode materials. , It was found to exhibit significant EDLC values. Supercapacitive values are particularly high when these 2D nanomaterials are used in combination with small amounts of nanographene sheets (especially monolayer graphene). The required monolayer graphene may be 0.1 wt% to 50 wt%, more preferably 0.5 wt% to 25 wt%, most preferably 1 wt% to 15 wt%.

In the present invention, there is no limitation on the type of liquid electrolyte that can be used in the supercapacitors: aqueous, organic, gel, and ionic liquids. Typically, electrolytes for supercapacitors consist of dissolved chemicals (eg, salts) that decompose into solvents and positive ions (cations) and negative ions (anions), making the electrolyte electrically conductive. The more ions the electrolyte contains, the better its conductivity, which also affects the capacitance. In supercapacitors, the electrolyte provides molecules for separating monolayers in the Helmholtz bilayer (electrical bilayer) and delivers ions for pseudocapacitance.

Water is a relatively good solvent for dissolving inorganic chemicals. Acids such as sulfuric acid (H ₂ SO ₄ ), alkalis such as potassium hydroxide (KOH), or quaternary phosphonium salts, sodium perchlorate (NaClO ₄ ), lithium perchlorate (LiClO ₄ ) or lithium hexafluoride arsenate (LiAsF _When added together with a salt such as ₆ ), water gives a relatively high conductivity value. Aqueous electrolytes have a decomposition voltage of 1.15 V per electrode and a relatively low operating temperature range. Supercapacitors based on water electrolytes exhibit low energy density.

Alternatively, the electrolyte may be an organic solvent such as acetonitrile, propylene carbonate, tetrahydrofuran, diethyl carbonate, γ-butyrolactone, and tetraethylammonium tetrafluoroborate (N (Et) ₄ BF ₄ ) or triethyl It may contain a solute having a quaternary ammonium salt or alkyl ammonium salt such as (methyl) tetrafluoroborate (NMe (Et) ₃ BF ₄ ). Organic electrolytes are more expensive than aqueous electrolytes, but they have a higher decomposition voltage (2.7 V capacitor voltage), and a higher temperature range, typically 1.35 V per electrode. Lower electrical conductivity (10-60 mS / cm) of the organic solvent leads to lower power density, but higher energy density, because the energy density is proportional to the square of the voltage.

미만이면 염은 이온성 액체로 간주된다. 융점이 실온(25℃ 이하인 경우, 염은 실온 이온성 액체(RTIL)로 지칭된다. IL 염은 큰 양이온과 전하-비편재화 음이온의 조합으로 인한 약한 상호작용을 특징으로 한다. 그 결과 유연성(음이온) 및 비대칭성(양이온)으로 인해 결정화 경향이 낮아진다.Ionic liquids consist only of ions. Ionic liquids are low melting salts that are in the molten or liquid state when they are above a predetermined temperature. For example, the melting point is 100

If less than salt is considered an ionic liquid. If the melting point is room temperature (up to 25 ° C.), the salt is referred to as room temperature ionic liquid (RTIL) .IL salts are characterized by a weak interaction due to the combination of large cations and charge-unlocalized anions. ) And asymmetry (cationic) lowers the tendency of crystallization.

Commonly known ionic liquids are formed by the combination of 1-ethyl-3-methylimidazolium (EMI) cations with N , N -bis (trifluoromethane) sulfonamide (TFSI) anions. This combination provides a fluid with ionic conductivity comparable to many organic electrolyte solutions and low decomposition tendencies up to about 300-400 ° C. and low vapor pressure. This generally means low volatility and nonflammability and therefore means a much safer electrolyte for batteries.

Basically, ionic liquids consist of organic ions which are subjected to an essentially unlimited number of structural modifications due to the ease of preparation of a wide variety of components. Thus, various types of salts can be used to design ionic liquids with desired properties for a given application. These include, inter alia, imidazolium, pyrrolidinium and quaternary ammonium salts as cations, and bis (trifluoromethanesulfonyl) imides as anions, bis (fluorosulfonyl) imides, and hexafluorophosphate do. Ionic liquids are divided into different classes based on their composition, basically including the aprotic, proton and zwitterionic types, each of which is suitable for a particular application.

Common cations of room temperature ionic liquids (RTIL) include tetraalkylammonium, di-, tri-, and tetra-alkylimidazolium, alkylpyridinium, dialkylpyrrolidinium, dialkylpiperidinium, tetraalkylphosphonium, And trialkylsulfonium. Common anions RTIL is ^{_{BF 4 -, B (CN)}} 4 -, CH 3 BF 3 -, CH 2 CHBF 3 -, CF 3 BF 3 -, C 2 F 5 BF 3 -, n -C 3 F 7 BF 3 _{^{-, n -C 4 F 9 BF}} 3 -, PF 6 -, CF 3 CO 2 -, CF 3 SO 3 -, N (SO 2 CF 3) 2 -, N (COCF 3) (SO 2 CF 3) - _{, N (SO 2 F) 2} -, N (CN) 2 -, C (CN) 3 -, SCN -, SeCN -, CuCl 2 -, AlCl 4 -, F (HF) 2.3 - and the like, but this It is not limited. Relatively speaking, imidazole ryumgye or sulfo nyumgye cations and complex halide anions, such as _{^{AlCl 4 -, BF 4 -,}} CF 3 CO 2 -, CF 3 SO 3 -, NTf 2 -, N (SO 2 F) 2 -, Or a combination of F (HF) _2.3 ⁻ results in an RTIL with good functional conductivity.

RTIL has high intrinsic ionic conductivity, high thermal stability, low volatility, low (substantially zero) vapor pressure, nonflammability, ability to hold liquids over a wide temperature range above and below room temperature, high polarity, high viscosity, and extensive electrical It may have conventional properties such as chemical windows. Except for the high viscosity, these properties are desirable attributes when using RTIL as an electrolyte component (salt and / or solvent) in a supercapacitor.

For the production of quasi-capacitors (supercapacitors that act on the development of quasi-capacitance through the formation of redox pairs), the anode active material or cathode active material is composed of graphene sheets and metal oxides, conductive polymers, organic materials, non-graphene carbon It can be designed to contain a redox pair partner material selected from materials, inorganic materials, or combinations thereof. Many materials that are capable of mating with reduced graphene oxide sheets are well known in the art. In this study, we found that graphene halides (eg, graphene fluorides), graphene hydrides, and nitrified graphene work with a wide variety of partner materials to form redox pairs for pseudocapacitance development. I realized I could.

For example, metal oxides or inorganic materials that play such roles include RuO ₂ , IrO ₂ , NiO, MnO ₂ , VO ₂ , V ₂ O ₅ , V ₃ O ₈ , TiO ₂ , Cr ₂ O ₃ , Co ₂ O ₃ , Co ₃ O ₄ , PbO ₂ , Ag ₂ O, MoC _x , Mo ₂ N, or a combination thereof. In general, the inorganic material may be selected from metal carbides, metal nitrides, metal borides, metal dichalcogenides, or combinations thereof. Preferably, the desired metal oxide or inorganic material is niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, vanadium, chromium, cobalt, manganese, iron, which is nanowire, nanodisk, nanoribbon, or nanoplate shaped. Or oxides of nickel, dichalcogenide, trichalcogenide, sulfides, selenides, or tellurides. These materials may be in the form of a simple mixture with a sheet of graphene material, but are preferably formed of a wetted active material mixture (eg in the form of a slurry) and before being impregnated into the pores of the conductive porous layer. It may be in the form of nanoparticles or nano-coating physically or chemically bonded to the surface of the.

The rope-shaped cell of the present invention has many unique features, some of which are summarized below:

By definition, a rope-type supercapacitor means a supercapacitor containing at least a rod or filament shaped anode and a rod or filament shaped cathode, combined in braid or twisted yarn. Supercapacitors have a length and diameter or thickness, with an aspect ratio (length to diameter or length to thickness ratio) of at least 10, preferably at least 20. Rope type supercapacitors may have a length greater than 1 m, or even greater than 100 m. The length may be as short as 1 μm, but typically 10 μm to 10 m, more typically micrometers to several meters. Indeed, there is no theoretical limit to the length of this type of rope type supercapacitor.

The rope-type supercapacitor of the present invention is very flexible and can be easily bent to have a radius of curvature greater than 10 cm. The supercapacitor can be bent to substantially conform to the shape of the interior space or interior compartment of the vehicle. The empty space or interior compartment may be a trunk, a door, a hatch, a spare tire compartment, an area under the seat or an area under the dashboard. The supercapacitor is detachable from the vehicle and can be bent to conform to the shape of other voids or interior compartments.

One or more units of the rope-type supercapacitors of the present invention may comprise clothing, belts, carrying straps, luggage straps, weapon straps, instrument straps, helmets, hats, boots, foot covers, gloves, wrist covers, watch bands, It can be integrated into jewelry articles, animal collars or animal harnesses.

One or more units of the rope-type supercapacitor of the present invention may be a garment, belt, carrying strap, baggage strap, weapon strap, instrument strap, helmet, hat, boots, foot cover, gloves, wrist cover, watch band, jewelry article, animal It can be detachably integrated into a collar or animal harness.

In addition, the rope supercapacitors of the invention correspond to the inner radius of the hollow bicycle frame.

Hereinafter, the inventors have provided examples for several different types of anode active materials, cathode active materials, and conductive porous rods (eg, graphite foams, graphene foams, and metal foams) to illustrate the best embodiments of the present invention. To provide. These exemplary embodiments and other parts and figures herein are suitably suitable to enable those skilled in the art to practice the invention, either individually or in combination. However, these examples should not be construed as limiting the scope of the invention.

Example 1 Illustrative Examples of Electrically Conductive Porous Rods or Filaments as Porous Current Collectors for Accommodating an Active Material-Electrolyte Mixture

For use as a conductive porous rod at the anode or cathode, various types of metal foams (which serve as current collectors), carbon foams, and fine metal webs such as Ni foams, Cu foams, Al foams, Ti foams, Ni Mesh / web, stainless steel fiber mesh and the like are commercially available. Metal-coated polymer foams and carbon foams can also be used as current collectors. In making the flexible supercapacitors of the macroscopic shape adaptive rope type, the most preferable thickness / diameter range of such conductive porous rods is 50 to 1000 μm, preferably 100 to 800 μm, more preferably 200 to 600 μm. In preparing microscopic rope-shaped supercapacitors (eg, having a diameter of 100 nm to 100 μm), graphene foams, graphene airgel foams, porous carbon fibers ( For example, electrospinning of polymer fibers, carbonization of polymer fibers, and activation of the resulting carbon fibers), and porous graphite fibers can be used.

Example 2: Ni foam and CVD graphene foam-based porous rod supported on Ni foam mold

에서 CH₄를 분해함으로써 니켈 발포체에 탄소를 도입한 후, 니켈 발포체의 표면에 그래핀 필름을 증착시켰다. 니켈과 그래핀 간의 열 팽창 계수 차이로 인해, 그래핀 필름 상에 리플(ripples)과 주름(wrinkles)이 형성되었다. 본 실시예에서 제조된 네 가지 유형의 발포체, 즉 Ni 발포체, CVD 그래핀-코팅 Ni 발포체, CVD 그래핀 발포체(Ni은 에칭 제거됨), 및 전도성 중합체 결합된 CVD 그래핀 발포체를 본 발명의 리튬 전지에서 집전체로 사용하였다.Methods of making CVD graphene foams are disclosed in Chen, Z. et al. "Three-dimensional flexible and conductive interconnected graphene networks grown by chemical vapor deposition", Nature Materials, 10, 424-428 (2011). Nickel foam, a porous structure with interconnected 3D nickel scaffolds, was selected as a template for the growth of graphene foams. Briefly, 1,000 under atmospheric pressure

Carbon was introduced into the nickel foam by decomposing CH _{4 at} , followed by depositing a graphene film on the surface of the nickel foam. Due to the difference in thermal expansion coefficient between nickel and graphene, ripples and wrinkles were formed on the graphene film. The four types of foams produced in this example, namely Ni foams, CVD graphene-coated Ni foams, CVD graphene foams (Ni is etched removed), and conductive polymer-bonded CVD graphene foams were described. Was used as the current collector.

In order to recover (separate) the graphene foam from the supporting Ni foam, the Ni frame was etched away. In the method proposed by Chen et al., A poly (methyl) film on the surface of the graphene film as a support to prevent the graphene network from collapsing during nickel etching, prior to etching away the nickel skeleton with a hot HCl (or FeCl ₃ ) solution. A thin layer of methacrylate (PMMA) was deposited. After carefully removing the PMMA layer with hot acetone, a weak graphene foam sample was obtained. The use of the PMMA support layer was considered to be important for making standalone films of graphene foam. Instead, graphene was bonded to each other using a conductive polymer as the binder resin while etching away Ni. The thickness / diameter range of the graphene foam or Ni foam ranged from 35 μm to 600 μm.

Ni foam or CVD graphene foam as used herein is intended as a conductive porous rod (CPR) for receiving components (anode or cathode active material + optional conductive additive + liquid electrolyte) for the anode or cathode or both. For example, prelithiated Si nanoparticles (as an anode active material for lithium ion capacitors) dispersed in an organic liquid electrolyte (eg, LiPF ₆ 1 to 5.5 M dissolved in PC-EC) may be made into a gel-like mass. Which was transferred from the feeder roller to the porous surface of the Ni foam continuously fed to produce the anode electrode (as in schematic E in FIG. 1D).

Graphene sheets (300-750 nm long) dispersed in the same liquid electrolyte were made of cathode slurry, which was sprayed onto the porous surface of continuous Ni foam rods to form cathode electrodes. The porous foam rod (first electrode) containing the prelithiated Si nanoparticle-electrolyte mixture impregnated into the foam pores is wrapped by a porous separator layer (porous PE-PP copolymer). The two electrodes are then combined into twisted yarns and then cased into a thin polymer shell to obtain a rope-type lithium ion capacitor.

Separately, the mixture of isolated graphene sheets and liquid electrolyte was impregnated into the pores of the graphene foam rods, which were then wrapped in a separator film to make one electrode. Another electrode of the same porous rod and the same mixture was prepared in a similar manner. Two bars were then combined to make a twisted yarn, which was then cascaded into a plastic sheath.

Example 3 Graphite Foam-Based Conductive Porous Rods from Pitch-Based Carbon Foam

의 온도까지 가열하였다. 이 시점에, 진공을 질소 블랭킷(blanket)으로 해제한 후, 최대 1,000 psi의 압력을 가하였다. 이어서, 시스템의 온도를 800

까지 올렸다. 2

분의 속도로 이를 수행하였다. 적어도 15분 동안 온도를 유지하여 침액(soak)을 달성한 후, 노 전원을 끄고, 대략 2 psi/분의 속도로 압력을 해제하면서 대략 1.5

분의 속도로 실온까지 냉각시켰다. 최종 발포체의 온도는 630

및 800

였다. 냉각 사이클 동안, 압력을 점차적으로 대기 상태로 해제한다. 이어서, 발포체를 질소 블랭킷 하에 1050

로 열처리(탄화)한 후, 흑연 도가니에서 아르곤 하에 2500

및 2800

로 개별적으로 열처리(흑연화) 하였다. 흑연 발포 막대는 75 내지 500 μm의 두께 범위에서 이용 가능하였다.Pitch powder, granules, or pellets are placed in an aluminum mold having the final shape of the desired foam. Mitsubishi ARA-24 mesophase pitch was used. Approximately 300 after evacuating the sample to less than 1 torr

Heated to temperature. At this point, the vacuum was released with a nitrogen blanket and then a pressure of up to 1,000 psi was applied. Then, the temperature of the system is 800

Raised up. 2

This was done at the rate of minutes. After maintaining the temperature for at least 15 minutes to achieve soak, turn off the furnace and release the pressure at approximately 2 psi / min to approximately 1.5

Cool to room temperature at the rate of minutes. The final foam temperature is 630

And 800

It was. During the cooling cycle, the pressure is gradually released to the atmosphere. The foam is then 1050 under a nitrogen blanket

After heat treatment (carbonization), 2500 under argon in graphite crucible

And 2800

The furnaces were individually heat treated (graphitized). Graphite foam bars were available in the thickness range of 75-500 μm.

Example 4 Preparation of Graphene Oxide (GO) and Reduced Graphene Oxide (RGO) Nanosheets from Natural Graphite Powders

Natural graphite from Huadong Graphite Co. (Qingdao, China) was used as starting material. GO was obtained according to the well-known modified Hummers method which included two oxidation steps. In a general procedure, first oxidation was achieved under the following conditions: 1100 mg of graphite was placed in a 1000 ml boiling flask. Then 20 g K ₂ S ₂ O ₈ , 20 g P ₂ O ₅ , and 400 mL H ₂ SO ₄ concentrated aqueous solution (96%) were added to the flask. The mixture was heated at reflux for 6 hours and then left undisturbed at room temperature for 20 hours. The oxidized graphite was filtered and washed with sufficient distilled water until neutral pH. At the end of this first oxidation, the wet cake-like material was recovered.

에서 2시간 동안 교반하고(샘플 색이 짙은 녹색으로 변함), 이어서 140 mL의 물을 첨가하였다. 15분 후, 물 420 mL와 30 wt% H₂O₂의 수용액 15 mL를 첨가하여 반응을 정지시켰다. 이 단계에서 샘플 색이 밝은 노란색으로 변했다. 금속 이온을 제거하기 위해, 혼합물을 여과하고 1:10 HCl 수용액으로 세정하였다. 회수된 물질을 2700 g로 약하게 원심분리하고 탈이온수로 세정하였다. 최종 생성물은, 건조 추출물로부터 추정할 때, 1.4 wt%의 GO를 함유하는 습윤 케이크였다. 이어서, 습윤 케이크 물질을 약하게 초음파 처리하여 GO 시트의 액체 분산액을 얻고, 이를 탈이온수에서 희석하였다.For the second oxidation process, the previously recovered wet cake was placed in a boiling flask containing 69 mL of H ₂ SO ₄ concentrated aqueous solution (96%). The flask was placed in an ice bath with the slow addition of 9 g KMnO ₄ . Care was taken to prevent overheating. The resulting mixture was 35

Was stirred for 2 h (sample color turned dark green), and then 140 mL of water was added. After 15 minutes, the reaction was stopped by adding 420 mL of water and 15 mL of an aqueous solution of 30 wt% H ₂ O ₂ . At this stage, the sample color turned bright yellow. To remove metal ions, the mixture was filtered and washed with 1:10 HCl aqueous solution. The recovered material was lightly centrifuged at 2700 g and washed with deionized water. The final product was a wet cake containing 1.4 wt% GO, estimated from the dry extract. The wet cake material was then slightly sonicated to give a liquid dispersion of the GO sheet, which was diluted in deionized water.

로 가열하고 1시간 동안 환류시켰다. 반응 후 측정된 pH 값은 약 9였다. 환원 반응 동안 샘플의 색이 진한 검은색으로 변하였다.The wet cake was diluted in an aqueous solution of surfactant instead of pure water to obtain surfactant-stabilized RGO (RGO-BS). A commercially available mixture of sodium cholate (50 wt%) and sodium deoxycholate (50 wt%) provided by Sigma Aldrich was used. The weight fraction of surfactant was 0.5 wt%. This fraction was kept constant in all samples. Sonication was performed using a Branson Sonifier S-250A operating at a 20 kHz frequency equipped with a 13 mm step disruptor horn and a 3 mm tapered microtip. For example, 10 mL of an aqueous solution containing 0.1 wt% GO was sonicated for 10 minutes and then centrifuged at 2700 g for 30 minutes to remove large particles, aggregates, and impurities that did not dissolve. The GO in the obtained state was chemically reduced in accordance with a method comprising adding 10 mL of 0.1 wt% GO aqueous solution to a 50 mL boiling flask to obtain an RGO. Then 10 μL of a 35 wt% N ₂ H ₄ (hydrazine) aqueous solution and 70 mL of 28 wt% aqueous NH ₄ OH (ammonia) solution were added to the mixture, which was stabilized with a surfactant. 90 solution

Heated to and refluxed for 1 h. The pH value measured after the reaction was about 9. The color of the sample turned dark black during the reduction reaction.

RGO has been used as an electrode active material (with a single or redox pair partner material) in either or both of the anode and cathode in some supercapacitors of the present invention. The wet anode active material-electrolyte mixture and the cathode active material-electrolyte mixture were respectively delivered separately to the surface of the graphite foam to form the anode and the cathode. A rope-type battery was then fabricated, where one filamentary electrode (eg, anode) and one filamentary electrode (cathode) were combined to form braids, twisted yarns, and the like.

For comparison, slurry coating and drying procedures were performed to prepare conventional electrodes. The separator disposed between the electrode and the two dried electrodes was then assembled, placed in an Al-plastic laminate packaging sheath, and then injected with a liquid electrolyte to form a conventional supercapacitor cell.

Example 5 Preparation of Pure Graphene Sheet (0% Oxygen)

Recognizing the possibility of a high defect population in GO sheets that acts to reduce the conductivity of individual graphene faces, the inventors have found that the use of pure graphene sheets (unoxidized oxygen free, non-halogenated halogen free, etc.) It was decided to study whether the implementation of an active material having high electrical conductivity and thermal conductivity in an electric double layer capacitor (EDLC supercapacitor) can be induced. Pre-lithiated pure graphene and pre-sodiumated pure graphene were also used as anode active materials for lithium-ion capacitors and sodium-ion capacitors, respectively. Pure graphene sheets were prepared using direct sonication or liquid phase manufacturing.

In a general procedure, 5 g of graphite flakes ground to a size of about 20 μm or less were dispersed in 1,000 mL of deionized water (containing 0.1 wt% dispersant (Zonyl ^® FSO from DuPont)) to obtain a suspension. The graphene sheets were peeled, separated, and sized for 15 minutes to 2 hours using an ultrasonic energy level of 85 W (Branson S450 sonicator). The resulting graphene sheet is pure graphene that has never been oxidized, contains no oxygen and is relatively free of defects. Pure graphene is essentially free of non-carbon elements.

Pure graphene sheets with electrolyte were incorporated into supercapacitors using both the procedures of the present invention and conventional procedures such as slurry coating, drying and layer laminating.

Example 6: Preparation of MoS ₂ / RGO Hybrid Materials as Cathode Active Materials of Pseudo-Supercapacitors

에서의 단일 단계 용매열합성 반응에 의해 초박형 MoS₂/RGO 하이브리드를 합성하였다. 일반적인 절차에서, 10 ml의 DMF에 분산된 10 mg의 GO에 22 mg의 (NH₄)₂MoS₄를 첨가하였다. 투명하고 균질한 용액이 얻어질 때까지 혼합물을 실온에서 약 10분 동안 초음파 처리하였다. 그 후, 0.1 ml의 N₂H₄*?*H₂O를 첨가하였다. 반응 용액을 40 mL의 테프론-라이닝 오토클레이브로 옮기기 전에 30분 동안 추가로 초음파 처리하였다. 이 시스템을 200

의 오븐에서 10시간 동안 가열하였다. 생성물을 8000 rpm으로 5분 동안 원심분리하여 회수하고, 탈이온수로 세척하고 원심분리로 다시 회수하였다. 세척 단계는 대부분의 DMF가 확실히 제거되도록 적어도 5회 반복하였다. 마지막으로, 생성물을 건조시키고, 액체 전해질과 혼합하여 탄소 발포체로의 함침을 위한 활성 캐소드 혼합물 슬러리를 제조하였다.In this example, various inorganic materials were investigated. For example, 200 of (NH ₄ ) ₂ MoS ₄ and hydrazine in an N , N -dimethylformamide (DMF) solution of oxidized graphene oxide (GO)

Ultra-thin MoS ₂ / RGO hybrids were synthesized by a single step solvent thermosynthesis reaction at. In a general procedure, 22 mg (NH ₄ ) ₂ MoS ₄ was added to 10 mg GO dispersed in 10 ml DMF. The mixture was sonicated at room temperature for about 10 minutes until a clear and homogeneous solution was obtained. Thereafter, 0.1 ml of N ₂ H ₄ *? * H ₂ O was added. The reaction solution was further sonicated for 30 minutes before being transferred to 40 mL of Teflon-lining autoclave. This system 200

Heated in an oven for 10 hours. The product was recovered by centrifugation at 8000 rpm for 5 minutes, washed with deionized water and recovered again by centrifugation. The washing step was repeated at least five times to ensure that most of the DMF was removed. Finally, the product was dried and mixed with the liquid electrolyte to prepare an active cathode mixture slurry for impregnation with carbon foam.

Example 7: Preparation of Graphene Fluoride (GF) Sheet as Supercapacitor Active Material

We have used several methods for GF preparation, but we describe only one method as an example here. In a conventional procedure, highly exfoliated graphite (HEG) was prepared from the intercalating compound Ρ ₂ F · × ClF ₃ . HEG was further fluorinated by chlorine trifluoride vapor to produce fluorinated highly exfoliated graphite (FHEG). The precooled Teflon reactor was charged with 20-30 mL of liquid precooled ClF ₃ and the reactor was sealed and cooled to liquid nitrogen temperature. Thereafter, less than 1 g of HEG was placed into a vessel having a hole such that ClF ₃ gas was approached and positioned inside the reactor. After 7-10 days, a yellowish-grey product with a formula of approximately C ₂ F was formed.

A small amount of FHEG (approximately 0.5 mg) was then mixed with 20-30 mL of organic solvent (methanol and ethanol respectively) and sonicated for 30 minutes (280 W) to induce the formation of a homogeneous yellowish dispersion. . Upon removal of the solvent, the dispersion became a brownish GF powder.

Example 8: Preparation of Nitrogenated Graphene Sheet as Supercapacitor Electrode Active Material

Graphene oxide (GO) synthesized in Example 2 was ground finely with different ratios of urea and the pelletized mixture was heated in a microwave reactor (900 W) for 30 seconds. The product was washed several times with deionized water and dried in vacuo. In this method, graphene oxide was simultaneously reduced and doped with nitrogen. The products obtained in graphene: urea mass ratios of 1: 0.5, 1: 1 and 1: 2 are named NGO-1, NGO-2 and NGO-3, respectively, and the nitrogen content of these samples is 14.7 by elemental analysis, respectively. Weight percent, 18.2 weight percent and 17.5 weight percent. These nitrogenated graphene sheets remain dispersible in water. The resulting suspension was dried to yield nitrified graphene powder. The powder was mixed in the liquid electrolyte to form a slurry for the impregnation of the conductive porous rod / filament into the pores.

Example 9 Preparation of Two-dimensional (2D) Layered Bi ₂ Se ₃ Chalcogenide Nanoribbons

The preparation of (2D) layered Bi ₂ Se ₃ chalcogenide nanoribbons is well known in the art. For example, Bi ₂ Se ₃ nanoribbons were grown using the vapor-liquid-solid (VLS) method. The nanoribbons prepared herein, on average, range from 30 to 55 nm in thickness and range from hundreds of nanometers to several micrometers in width and length. Larger nanoribbons were ball milled to reduce the transverse dimension (length and width) to less than 200 nm. The nanoribbons prepared by this method (with or without graphene sheets or exfoliated graphite flakes) were used as supercapacitor electrode active materials.

Example 10 MXenes Powder + Chemically Activated RGO

Selected MXenes were produced by partially etching certain elements from a laminated structure of metal carbide, such as Ti ₃ AlC ₂ . For example, aqueous 1 M NH ₄ HF ₂ was used as a corrosion solution for Ti ₃ AlC ₂ at room temperature. Typically, the MXene surface is terminated by O, OH, and / or F groups, whereby they are usually referred to as M _{n + 1} X _n T _x, where M is a transition metal and X is C and / or N, T represents terminators (O, OH, and / or F), n = 1, 2 or 3 and x is the number of terminators. The MXene materials studied include Ti ₂ CT _x , Nb ₂ CT _x , V ₂ CT _x , Ti ₃ CNT _x , and Ta ₄ C ₃ T _x . Typically, 35-95% MXene and 5-65% graphene sheets were mixed in the liquid electrolyte and impregnated into the pores of the conductive porous filaments.

Example 11: Preparation of MnO ₂ -graphene redox pairs as pseudocapacitive active materials

에서 12시간 동안 건조시켰다. 샘플은 분말 형상의 그래핀-지지 MnO₂이고, 이를 액체 전해질에 분산시켜 슬러리를 형성하고 발포 집전체의 세공에 함침시켰다.MnO ₂ powders were synthesized in two ways (with or without graphene sheets, respectively). In one method, 0.1 mol / L aqueous KMnO ₄ solution was prepared by dissolving potassium permanganate in deionized water. Meanwhile, 13.32 g of high purity sodium bis (2-ethylhexyl) sulfosuccinate surfactant was added to 300 mL of isooctane (oil) and stirred well to obtain an optically clear solution. To this solution was then added 32.4 mL of 0.1 mol / L KMnO ₄ solution and a selected amount of GO solution and sonicated for 30 minutes to give a dark brown precipitate. The product was separated, washed several times with distilled water and ethanol, 80

Dried for 12 h. The sample is powdered graphene-supported MnO ₂ , which was dispersed in a liquid electrolyte to form a slurry and impregnated into the pores of the foam current collector.

Example 12 Evaluation of Various Supercapacitor Cells

In most of the examples studied, both the supercapacitor cells of the present invention and their conventional counterparts were fabricated and evaluated. The latter cell for comparison purposes was prepared by conventional procedures such as slurry coating of electrodes, drying of electrodes, assembly of anode layers, separators, and cathode layers, packaging of assembled laminates, and injection of liquid electrolyte. In a typical cell, the electrode (cathode or anode) typically contains 85% of the electrode active material (eg, graphene, activated carbon, inorganic nanodisks, etc.), 5% Super-P (acetylene black based conductive additive), and It consisted of 10% PTFE, which were mixed and coated on Al foil. The thickness of the electrode is approximately 100 μm. For each sample, both coin size and pouch cell were assembled in a glove box. Capacity was measured by constant current experiments using an Arbin SCTS electrochemical test instrument. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were performed on an electrochemical workstation (CHI 660 System, USA).

Capacitive charge / discharge tests were performed on the samples to assess electrochemical performance. For the constant current test, the specific quantity q is calculated as the following equation (1):

q = I * t / m (1)

Where I is the constant current (mA), t is the time (h), and m is the mass of the cathode active material (grams). Using the voltage V , the specific energy E is calculated as follows:

Vdq (2) E =

Vdq (2)

The specific power P is calculated as the following formula (3):

P = ( E / t ) (W / kg) (3)

Where t is the total charge or discharge step time (h).

The cell's non-capacitance ( C ) is expressed as the slope at each point in the voltage versus specific capacity graph:

C = dq/ dV (4)

For each sample, several current densities (indicative of charge / discharge rates) were added to determine the electrochemical reaction, allowing calculation of the energy density and power density values required to build the ragon plot (power density vs. energy density). Make it possible.

FIG. 5 shows a ragon diagram (weight and volumetric power density vs. energy density) of two sets of symmetric supercapacitor (EDLC) cells containing a reduced graphene oxide (RGO) sheet as electrode active material and EMIMBF4 ionic liquid as electrolyte. . One of two series of supercapacitors was made according to an embodiment of the present invention, and the other was made by conventional slurry coating of the electrode. Several important observations can be made from these data:

(A) The weight and volumetric energy density and power density of the supercapacitor cells (rope-shaped cells) produced by the method of the present invention are significantly higher than their counterparts (denoted as "normal") produced by conventional methods. . The difference is very dramatic, which is mainly due to the high active material mass feed (greater than 20 mg / cm ² ) associated with the cells of the present invention, the reduced ratio of overhead (inactive) components relative to the active material weight / volume, the need for binder resin, foaming This is due to the ability of the method of the present invention to more effectively pack the graphene sheet into the pores of the current collector.

(B) For cells produced by conventional methods, the absolute magnitudes of the volumetric energy density and the volumetric power density are significantly smaller than their weight energy density and the weight power density, which are RGO systems prepared by conventional slurry coating methods. This is due to the very low tap density (packing density of 0.25 g / cm ³ ) of the electrode.

(C) In contrast, for a cell produced by the method of the present invention, the absolute magnitude of the volumetric energy density (23.8 Wh / L) and the volumetric power density (9,156 W / L) is greater than its weight energy density and weight power density. This is due to the relatively high tap density (packing density of 1.05 g / cm ³ ) of the RGO-based electrode produced by the method of the present invention.

(D) The volumetric energy density and the volumetric power density of the corresponding supercapacitors produced by conventional processes are 3.1 Wh / L and 1,139 W / L, respectively, which are lower by one digit. These are dramatic and unexpected.

FIG. 6 shows a Ragon diagram (both weight and volume power density versus energy density) of a symmetric supercapacitor (EDLC) cell containing activated carbon (AC) particles and an organic liquid electrolyte as electrode active material (weight and volume power density versus energy density). Shows. Experimental data were obtained from those by conventional slurry coating of supercapacitors (rope-shaped cells) and electrodes made by the process of the invention.

These data also show that both the weight and volumetric energy density and power density of the supercapacitor cells produced by the method of the present invention are significantly higher than their counterparts produced via conventional methods. Again the difference is large, which is mainly due to the high active material mass feed (greater than 15 mg / cm ² ) associated with the rope cells of the present invention, the reduced ratio of overhead (inactive) components relative to the active material weight / volume, the need for binder resins This is due to the ability of the method of the present invention to more effectively pack the graphene sheet into the pores of the foamed current collector. Highly porous activated carbon particles are not as easy to pack as densely as graphene sheets. As a result, in the case of AC-based supercapacitors, the absolute magnitude of the volumetric energy density and the volumetric power density is smaller than the magnitude of the corresponding gravimetric energy density and the gravimetric power density. However, the method of the present invention also surprisingly enables the AC particles to be packed with significantly higher tap densities (0.75 g / cm ³ ) than those achieved with conventional slurry coating processes (0.55 g / cm ³ ) in this study. do

FIG. 7A shows a Ragon diagram of a lithium ion capacitor (LIC) cell containing pure graphene sheet as cathode active material, prelithiated graphite particles as anode active material, and lithium salt (LiPF ₆ ) -PC / DEC as organic liquid electrolyte. . The data are for both LICs produced by the process of the invention and those by slurry coating of conventional electrodes. These data indicate that both the weight and volumetric energy density and power density of the LIC cells produced by the method of the present invention are significantly higher than their counterparts prepared by conventional methods. Again the difference is large, which is mainly due to the high active mass feed (> 15 mg / cm ^{2 at the} anode side) associated with the rope cells of the present invention. > 25 mg / cm ² on the and cathode side ), Reduced ratio of overhead (inactive) components to active material weight / volume, lack of binder resin, ability of the present invention to more effectively pack graphene sheets into pores of foamed current collectors.

In the case of LIC cells produced by conventional methods, the absolute magnitude of the volumetric energy density and the volumetric power density is significantly smaller than their weight energy density and the weight power density, which is pure graphene based produced by conventional slurry coating methods. This is due to the very low tap density of the cathode (average packing density of 0.75 g / cm ³ ). In contrast, for rope-type LIC cells produced by the method of the present invention, the absolute magnitude of the volumetric energy density and the volumetric power density is greater than the values of their weighted energy density and the weighted power density, which are determined by the method of the present invention. This is due to the relatively high tap density of the pure graphene based cathodes produced.

FIG. 7B shows a Ragon diagram of a sodium ion capacitor (NIC) cell containing pure graphene sheet as cathode active material, pre-sodiumated graphite particles as anode active material, and sodium salt (NaPF ₆ ) -PC / DEC as organic liquid electrolyte. . The data are for both LIC made by the process of the invention and those made by slurry coating of conventional electrodes. These data indicate that both the weight and volumetric energy density and power density of the NIC cells (rope-shaped cells) produced by the method of the present invention are significantly higher than their counterparts produced by conventional methods. Again the difference is dramatic, which is mainly due to the high active mass feed (> 15 mg / cm ^{2 at the} anode) associated with the cells of the invention. > 25 mg / cm ² on the and cathode side ), A reduced ratio of overhead (inactive) components to active material weight / volume, no need for binder resins, and the ability of the method of the present invention to more effectively pack the graphene sheet into the voids of the foamed current collector.

As many researchers have reported, it is important to point out that reporting energy and power density per weight of active material only in the Ragon plot may not provide a realistic picture of the performance of the assembled supercapacitor cell. The weight of other device components must also be taken into account. These overhead components, including current collectors, electrolytes, separators, binders, connectors and packaging, are inert materials and do not contribute to charge storage. They add only weight and volume to the device. Therefore, it is desirable to reduce the relative proportions of the overhead component weights and to increase the proportion of the active material. However, it was not possible to achieve this goal using conventional supercapacitor manufacturing processes. The present invention overcomes this long lasting most serious problem in the field of supercapacitors.

In a commercial supercapacitor having an electrode thickness of 150 to 200 μm (75 to 100 μm on each side of an Al foil current collector), the weight of the active material (ie, activated carbon) is about 25% to 30% of the total mass of the packaged cell. Occupies% Thus, coefficients of 3 to 4 are often used to extrapolate the energy or power density of the device (cell) from properties based solely on the weight of the active material. In most scientific papers, the reported properties are typically based only on the active material weight and the electrodes are typically very thin (<< 100 μm, mostly << 50 μm). The active material weight is typically 5% to 10% of the total device weight, which can be obtained by dividing the actual cell (device) energy or power density by a factor of 10 to 20 based on the corresponding active material weight. Means. Considering these coefficients, the properties reported in these papers do not actually look any better than those of commercial supercapacitors. Therefore, great care should be taken when reading and interpreting the performance data of supercapacitors reported in scientific papers and patent applications.

Example 13: Achievable Electrode Thickness and Its Effect on the Electrochemical Performance of Supercapacitor Cells

The electrode thickness of a supercapacitor can be thought of as a design parameter that can be freely adjusted to optimize device performance; In fact, however, supercapacitor thicknesses are limited in manufacturing and cannot produce electrodes of good structural integrity above a certain thickness level. The study also shows that this problem is even worse with graphene electrodes. The present invention solves this very important problem associated with supercapacitors.

In Figure 8, cell level weight (Wh / kg) and volumetric energy density (A) for the range of achievable electrode thicknesses of activated carbon-based symmetric EDLC supercapacitors produced by conventional methods and rope cells produced by the method of the present invention Wh / L) is plotted. Activated carbon-based electrode can be manufactured to a thickness of 100 to 200 ㎛ using a conventional slurry coating process. In contrast, however, there is no theoretical limitation on electrode thickness that can be achieved using the method of the present invention. Typically, the substantial electrode thickness is between 10 μm and 5000 μm, more typically between 50 μm and 2,000 μm, more typically between 100 μm and 1,000 μm and most typically between 200 μm and 800 μm.

These data further confirm the surprising effect of the method of the present invention on the manufacture of ultra-thick supercapacitor electrodes, which was not previously achievable. These ultra-thick electrodes significantly exceed the exceptionally high active material mass feed, typically 10 mg / cm ² (more typically more than 15 mg / cm ² , more typically more than 20 mg / cm ² , often 25 mg) more than / cm ² , and even more than 30 mg / cm ² ). These high active material mass feeds were not obtainable using conventional supercapacitors prepared by slurry coating processes.

More strikingly, typical cell level energy densities of commercial AC based supercapacitors are 3 to 8 Wh / kg and 1 to 4 Wh / L. In contrast, the method of the present invention enables supercapacitors containing the same type of electrode active material (AC) to deliver energy densities of up to 19.5 Wh / kg or 14.6 Wh / L. This increase in energy density was not considered possible in the supercapacitor industry.

The data summarized in FIG. 9 for the reduced graphene oxide based EDLC supercapacitor is also very significant and unexpected. Cell level weight and volumetric energy density are plotted against achievable electrode thickness ranges of RGO-based EDLC supercapacitors (organic liquid electrolytes) prepared by conventional methods and those made by the method of the present invention. In this figure, the weight (◆) and volume (▲) energy densities of the supercapacitors are usually based on the highest achieved electrode tap density of approximately 0.25 g / cm ³ , and the weight (■) of the rope-type supercapacitors of the present invention. And the volume (X) energy density is not the highest but has an electrode tap density of approximately 0.75 g / cm ³ . Such high tap densities have not been reported previously for untreated, inactive RGO electrodes.

These data show that the highest weight energy density achieved using an RGO-based EDLC supercapacitor cell produced by a conventional slurry coating method is approximately 12 Wh / kg, but that produced by the method of the present invention is 25.6 Wh / at room temperature. Indicates high weight energy density by kg. This is an unprecedented high energy density value in EDLC supercapacitors (based on total cell weight, not on electrode weight or active material weight alone). The observation that the volumetric energy density of the supercapacitor cell of the present invention is as high as 19.2 Wh / L is more impressive, which is six times larger than the 3.0 Wh / L achieved by conventional counterparts.

10 shows data of cell level weight and volume energy density for achievable electrode thickness ranges of pure graphene-based EDLC supercapacitors (organic liquid electrolyte) prepared by conventional methods and rope cells prepared by the method of the present invention. Is summarized in the diagram. The legends show the weight (◆) and volume (▲) energy densities of the conventional supercapacitors (the highest achieved electrode tap density of approximately 0.25 g / cm ³ ) and the weight (■) and volume (X) energy of the supercapacitors of the present invention. Density (electrode tap density of approximately 0.85 g / cm ³ ).

Remarkably, these EDLC supercapacitors (without any redox or similar capacity) deliver high weight energy densities at 32.3 Wh / kg, which is already the energy density (20-40 Wh / kg) of high-grade lead-acid cells. . EDLC supercapacitors are of high value because they can be charged and discharged for 250,000 to 500,000 cycles, as opposed to the typical 100 to 400 cycles of lead-acid batteries. This achievement is very dramatic and unpredictable in the field of supercapacitor technology. Additionally, carbon-based or graphene-based EDLC supercapacitors can be recharged in seconds, in contrast to the typical several hours of recharge time required for lead-acid cells. Although lead-acid batteries are known for their very negative environmental impacts, the supercapacitors of the present invention are environmentally beneficial.

Further important examples are cell level weight and volume for achievable electrode thickness ranges of pure graphene-based EDLC supercapacitors (ionic liquid electrolytes) prepared by conventional methods and rope cells made by the method of the present invention. The data summarized graphically in FIG. 11 for energy density is included. The weight (◆) and volume (▲) energy densities are for conventional supercapacitors (the highest achieved electrode tap density of approximately 0.25 g / cm ³ ), and the weight (■) and volume (X) energy densities are approximately 0.85 g. For a supercapacitor of the invention having an electrode tap density of / cm ³ . The pure graphene-based EDLC supercapacitors of the present invention are capable of storing cell-level energy densities of 38.6 Wh / kg, which are six times larger than can be achieved by conventional AC-based EDLC supercapacitors. Volumetric energy density values of 32.8 Wh / L are also unprecedented, 10 times greater than 3 to 4 Wh / L of commercial AC based supercapacitors.

Example 14: Influence on the weight percent of active material achievable in a cell and its electrochemical performance

Since the active material weight accounts for up to about 30% of the total mass of the packaged commercial supercapacitor, a factor of 30% should be used to estimate the energy or power density of the device from the performance data of the active material alone. Accordingly, the energy density of activated carbon of 20 Wh / kg (ie, based on the active material weight alone) will change to a packed cell of about 6 Wh / kg. However, this estimation is valid only for electrodes having a thickness and density similar to that of commercial electrodes (150 μm or carbon electrodes of about 10 mg / cm ² ). Thinner or lighter electrodes of the same active material will mean much lower energy or power density, based on cell weight. Accordingly, it may be desirable to produce a supercapacitor cell with a high active material ratio. Unfortunately, it has not previously been possible to achieve active material ratios of greater than 30% by weight for activated carbon based supercapacitors or greater than 15% by weight for graphene based supercapacitors.

The method of the present invention allows the supercapacitor to sufficiently exceed these limits for all active materials studied. In fact, the present invention makes it possible to raise the active material ratio by more than 90% if desired; Usually 15% to 85%, more typically 30% to 80%, even more typically 40% to 75%, and most usually 50% to 70%.

As shown in FIG. 12, the cell level weight energy density of activated carbon based EDLC supercapacitors (using organic liquid electrolyte) was plotted against achievable active material ratio (active material weight / total cell weight), which is 4.2% to 33.3%, This results in an energy density of 1.3 to 8.4 Wh / kg. The present invention enables the inventors to achieve a pure graphene content of 17.5% to 79% by weight in the supercapacitor cell, which results in a weight energy density of 4.9 to 19.5 Wh / kg. For example, FIG. 13 shows the cell level weight energy density versus achievable active material ratio (active material weight / total cell weight) in a supercapacitor cell for two series of pure graphene-based EDLC supercapacitors (both with organic liquid electrolyte). Graphically. Likewise, rope-type cells of the present invention containing a filament electrode impregnated with an active material-electrolyte mixture can be manufactured to have exceptionally high active material ratios and thus exceptionally high energy densities.

Example 15 Electrochemical Performance of Supercapacitor Cells Based on Different Porous or Foamed Structures as Various Electrode Active Materials and / or Current Collectors

In order to evaluate the effect of the foam structure, we choose to use RGO as an example of the electrode active material, but the type and properties of the current collector vary (porous rods or filaments). Metal foams (eg Ni and Ti foams), metal webs (eg stainless steel webs), 3D structures based on foamed metal sheets, metal fiber mats (steel fibers), metal nanowire mats (Cu nanowires) ), Conductive polymer nano-fiber mat (polyaniline), conductive polymer foam (e.g. PEDOT), conductive polymer coated fiber foam (polypyrrole coated nylon fiber), carbon foam, graphite foam, carbon aerogel, carbon zero gel, Graphene foam (Ni-supported CVD graphene), graphene oxide foam (obtained via freeze-dried GO-aqueous solution), reduced graphene oxide foam (RGO mixed with polymer and then carbonized), carbon fiber foam Various foams were chosen, ranging from graphite fiber foams, and exfoliated graphite foams (exfoliated graphite worms bonded by carbonized resin). This extensive and in-depth study led to the following important observations:

(A) The electrical conductivity of the foam material is an important parameter with higher conductivity, which tends to result in higher power density and faster supercapacitor reaction time.

(B) Porous levels are also important parameters that result in higher amounts of active materials with higher pore contents when considering the same volume, leading to higher energy densities. However, higher porosity levels are likely to slow the reaction time due to lower electron conductivity performance.

(C) Graphite foams and graphene foams provide better reaction times of supercapacitors. However, metal foams allow for easier formation or connection of tabs (terminal leads). Two leads are required for each cell.

Various electrode active materials have been studied for both EDLCs and redox supercapacitors, covering organic and inorganic materials and combined with aqueous, organic and ionic liquid electrolytes. Some examples of different classes of supercapacitors are summarized in the table below (Table 1) for illustrative purposes. They should not be construed as limiting the scope of the present application.

Examples of supercapacitors produced by the novel method and their counterparts produced by conventional slurry coating methods Sample ID Active material Electrolyte Electrode Diameter (μm) and Method Active material mass supply amount (g / ㎠) Weight Energy Density (Wh / kg) Volumetric Energy Density (Wh / L) PPy-1 Polypyrrole-cellulose 4.5 M NaCl in H ₂ O 503, rope 38 41 22 PPy-c Polypyrrole-cellulose 4.5 M NaCl in H ₂ O 185, typical 12.8 8.6 3.2 RuO ₂ -AC-1 RuO ₂ + AC 3.5 M NaCl in H ₂ O 348, rope 15 35.6 24.7 RuO ₂ -AC-c RuO ₂ + AC 3.5 M NaCl in H ₂ O 160, typical 7.2 11.6 7.7 NiO-RGO-1 NiO + Activate GO 5.5 M LiOH in H ₂ O 551, rope 26.2 40.5 33.2 NiO-RGO-c NiO + Activate GO 5.5 M LiOH in H ₂ O 160, typical 4.6 9.2 7.3 V ₂ O ₅ -NGn-1 V ₂ O ₅ + Nitrogenated Graphene THF + N (Et) ₄ BF ₄ 624, rope 27.1 41.1 35.2 V ₂ O ₅ -NGn-c V ₂ O ₅ + Nitrogenated Graphene THF + N (Et) ₄ BF ₄ 175, typical 5.6 7.2 5.6 MnO ₂ -RGO -1 MnO ₂ + RGO 3.5 MNa ₂ SO ₄ 405, rope 16.6 74 81 MnO ₂ -RGO -c MnO ₂ + RGO 3.5 MNa ₂ SO ₄ 187, typical 6.2 29 23 MoS ₂ -1 MoS ₂ / RGO Acetonitrile + N (Et) ₄ BF ₄ 355, rope 24.7 38.4 33.2 MoS ₂ -c MoS ₂ / RGO Acetonitrile N (Et) ₄ BF ₄ 155, typical 8.8 13.2 9.6 Ti ₂ CT _x -1 Ti ₂ C (OH) ₂ / Quinone GO 3 M LiOH in H ₂ O 331, rope 13.8 13.4 11.2 Ti ₂ CT _x -c Ti ₂ C (OH) ₂ / Quinone GO 3 M LiOH in H ₂ O 167, typical 4.5 6.7 4.2 CNT-1 Chopped MWCNT EMI-TFSI 275, rope 12.3 24.3 15.2 CNT-c Chopped MWCNT EMI-TFSI 95 2.3 6.2 3.2

These data further confirm the surprising superiority of the rope-type supercapacitor cell and manufacturing method of the present invention in terms of dramatic improvements in mass feed amount (ratio), electrode diameter / thickness, weight energy density, and volume energy density. Rope type supercapacitors of the present invention having active material / electrolyte-preimpregnated braid / yarn electrodes are consistently better than conventional supercapacitors in electrochemical characterization. The difference is surprisingly dramatic. In conclusion, the inventors are flexible shape adaptation, unexpectedly large active material mass feed (not previously achieved), excellent weight energy density (not previously achieved), and unprecedented high volumetric energy. We have successfully developed a new class of supercapacitors with density. The method of preparing an electrode by pre-impregnating the active material-electrolyte mixture of the present invention into a foamed current collector is a long time problem associated with graphene sheet-based supercapacitors (ie, thick electrode cannot be manufactured, graphene sheet loading). Difficulties in layer protection, low tap density, and low volumetric energy density) are also overcome.

Claims (55)

(a) a first electrically conductive porous rod having pores and a first mixture of a first electrode active material and a first electrolyte, wherein the first mixture is present in the pores of the first electrically conductive porous rod; 1 electrode;
(b) a porous separator surrounding or encasing the first electrode to form a separator-protected first electrode;
(c) a second electrode comprising a second electrically conductive porous rod having pores and a second mixture of second electrode active material and second electrolyte, wherein the second mixture is present in the pores of the second electrically conductive porous rod, The separator-protected first electrode and the second electrode being combined or twisted together to form a braid or seal; And
(d) a protective casing or sheath surrounding or casing the braid or yarn;
As a rope type supercapacitor comprising:
The first and / or second electrode active material contains a plurality of particles of carbon material and / or a plurality of graphene sheets, wherein the plurality of graphene sheets are single layer graphene or 1 to 10 graphene faces each, respectively. And a hydrophobic layer of graphene, wherein the plurality of particles of carbon material or graphene sheet have a specific surface area of at least 500 m ² / g as measured in the dry state. The rope type supercapacitor of claim 1 comprising a plurality of said first electrodes and / or a plurality of said second electrodes, at least one of said electrodes being an anode and at least one being a cathode. The rope type supercapacitor of claim 1, further comprising a porous separator surrounding or casing the second electrode to form a separator-protected second electrode. 4. The rope type supercapacitor of claim 3 further comprising a third electrolyte disposed between the braid or yarn and the protective casing or sheath. The method of claim 1, wherein the first or second electrode active material contains activated carbon particles or an isolated graphene sheet having a length or width smaller than 1 μm for impregnation into pores of the first or second electrode. Graphene sheets include pristine graphene, graphene oxide, reduced graphene oxide, graphene fluoride, nitrogenated or nitrogen doped graphene, hydrogenated or hydrogen doped graphene, boron doped graphene, chemistry Rope type supercapacitor selected from the group consisting of vaporized graphene, and combinations thereof. The method of claim 1, wherein the first or second electrode comprises: (a) a graphene sheet alone; (b) graphene sheets mixed with the porous carbon material; (c) a graphene sheet mixed with a partner material forming a redox pair with the graphene sheet to develop pseudocapacitance; Or (d) the graphene sheet and the porous carbon material mixed with a graphene sheet or a partner material forming a redox pair with the porous carbon material to develop a pseudocapacitance in the first or second electrode. A rope type supercapacitor containing as the only electrode active material, wherein no other electrode active material is present in the first or second electrode. A rope type supercapacitor having a length-to-diameter or length-to-thick aspect ratio of greater than 10,
(a) a first electrode comprising a first electrically conductive rod and a first mixture of first electrode active material and a first electrolyte, wherein the first mixture is deposited on or in the first electrically conductive rod; 1 electrode;
(b) a porous separator surrounding or casing the first electrode to form a separator-protected first electrode;
(c) a second electrode comprising a second electrically conductive porous rod having pores and a second mixture of second electrode active material and second electrolyte, wherein the second mixture is the pores of the second electrically conductive porous rod Present in; A second electrode, wherein the separator protected first electrode and the second electrode are twisted, twisted or helically combined with each other to form a braid or yarn; And
(d) a protective casing or sheath surrounding or casing the braid or yarn;
Including,
The first active material and / or the second active material contains a plurality of particles of carbon material and / or a plurality of graphene sheets, wherein the plurality of graphene sheets are single layer graphene or 1 to 10 graphene each, respectively. A rope-type supercapacitor containing a hydrophobic layer of graphene having a surface, wherein the plurality of particles of carbonaceous material or the graphene sheet have a specific surface area of at least 500 m ² / g as measured in a dry state. 8. The rope type supercapacitor of claim 7, further comprising a porous separator surrounding or casing the second electrode to form a separator-protected second electrode. 9. The rope type supercapacitor of claim 8 further comprising a third electrolyte disposed between the braid or yarn and the protective sheath. The at least one metal wire, conductive carbon / graphite of claim 1, wherein the rope-type battery has a first end and a second end, and the first electrode is embedded in, connected to, or integral with the first electrode. A rope type supercapacitor comprising a first terminal connector comprising fibers, or conductive polymer fibers. 11. The rope-type supercapacitor of claim 10, wherein the at least one metal wire, conductive carbon / graphite fibers, or conductive polymer fibers extend approximately from the first end to the second end. The method of claim 1, wherein the first or second electrically conductive porous rod is a metal foam, metal web, metal fiber mat, metal nanowire mat, conductive polymer fiber mat, conductive polymer foam, conductive polymer coated fiber foam, carbon foam Selected from graphite foam, carbon aerogel, carbon zero gel, graphene aerogel, graphene foam, graphene oxide foam, reduced graphene oxide foam, carbon fiber foam, graphite fiber foam, exfoliated graphite foam, and combinations thereof Rope type supercapacitors containing porous foam. 13. The rope-type supercapacitor of claim 12, wherein the porous foam has a cross section of circular, oval, rectangular, square, hexagonal, hollow or non-uniform shape. The rope type supercapacitor of claim 1, wherein the supercapacitor has a rope shape having a length / thickness or a length / diameter aspect ratio of greater than ten. 6. The method of claim 5, wherein the first or second electrode further contains a redox pair partner material selected from metal oxides, conductive polymers, organic materials, non-graphene carbon materials, inorganic materials, or combinations thereof. Wherein the partner material is combined with graphene or activated carbon to form a redox pair for pseudocapacitance. The method of claim 15, wherein the metal oxide is RuO ₂ , IrO ₂ , NiO, MnO ₂ , VO ₂ , V ₂ O ₅ , V ₃ O ₈ , TiO ₂ , Cr ₂ O ₃ , Co ₂ O ₃ , Co ₃ O ₄ , PbO ₂ , Ag ₂ O and a rope type supercapacitor selected from the group consisting of a combination thereof. The rope type supercapacitor of claim 15, wherein the inorganic material is selected from metal carbides, metal nitrides, metal borides, metal dichalcogenides, and combinations thereof. The method of claim 15, wherein the metal oxide or inorganic material is niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, vanadium, chromium, in the form of nanowires, nanodisks, nanoribbons, or nanoplatelets. A rope type supercapacitor selected from oxides, dichalcogenides, trichalcogenides, sulfides, selenides, or tellurides of an element selected from the group consisting of cobalt, manganese, iron, nickel and combinations thereof. The method of claim 15, wherein the inorganic material is bismuth selenide, bismuth telluride, transition metal dichalcogenide, transition metal trichalcogenide, niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, cobalt, manganese, Sulfides of iron, nickel or transition metals, niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, cobalt, manganese, selenides of iron, nickel or transition metals, niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium And nanodisks, nanoplates, nanocoats, or nanosheets of inorganic materials selected from the group comprising cobalt, manganese, iron, nickel or transition metals, tellurides, boron nitride, and combinations thereof; The nanodisk, nanoplate, nanocoat or nanosheet is a rope type supercapacitor having a thickness of less than 100 nm. The method of claim 1, wherein the first or second electrode active material is bismuth selenide, bismuth telluride, transition metal dichalcogenide, transition metal trichalcogenide, niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, Sulfides of cobalt, manganese, iron, nickel or transition metals, niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, cobalt, manganese, iron, nickel or transition metals selenide, niobium, zirconium, molybdenum, hafnium, tantalum Contains nanodisks, nanoplates, nanocoats or nanosheets of inorganic materials selected from the group comprising, tungsten, titanium, cobalt, manganese, iron, nickel or transition metals, tellurides, boron nitride, and combinations thereof the disk, plate, coat, or sheet as measured in the dry state, rope-type super capacitor having at least less than 100 nm thick and 200 m ² / g specific surface area Emitter. The method of claim 1, wherein the lithium ion capacitor or sodium ion capacitor, wherein the first or second electrode active material
(a) pre-lithiated and pre-sodiumated particles of natural graphite, artificial graphite, mesocarbon microbeads (MCMB), and carbon;
(b) prelithiated and pre-sodiumated silicon (Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), zinc (Zn), aluminum (Al), Nickel (Ni), cobalt (Co), manganese (Mn), titanium (Ti), iron (Fe), and cadmium (Cd);
(c) prelithiated and pre-sodiumated alloys or intermetallic compounds with other elements of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, or Cd, wherein the alloys or compounds are stoichiometric or non- Stoichiometric;
(d) prelithiated and presodiumated oxides, carbides, nitrides, sulfides, phosphides, selenium of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Fe, Ni, Co, Ti, Mn, or Cd; Cargoes, and tellurides, and mixtures or composites thereof; And
(e) combinations thereof
A rope type supercapacitor, which is an anode selected from the group consisting of: The method of claim 1, wherein the lithium ion capacitor or sodium ion capacitor, wherein the first electrode or the second electrode is pure graphene, graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide , Graphene iodide, hydrogenated graphene, nitrogenated graphene, boron doped graphene, nitrogen doped graphene, chemically functionalized graphene, physically or chemically activated or etched forms thereof, and their A rope type supercapacitor which is an anode containing a combination of prelithiated or presodiumated forms. The method of claim 1, wherein the sodium ion capacitor, wherein the first or second electrode is petroleum coke, carbon black, amorphous carbon, activated carbon, hard carbon, soft carbon, template carbon, hollow carbon nanowires, hollow carbon spheres, Or sodium titanate, NaTi ₂ (PO ₄ ) ₃ , Na ₂ Ti ₃ O ₇ , Na ₂ C ₈ H ₄ O ₄ , Na ₂ TP, Na _x TiO ₂ (x = 0.2 to 1.0), Na ₂ C ₈ H ₄ O ₄ , carboxylate, C ₈ H ₄ Na ₂ O ₄ , C ₈ H ₆ O ₄ , C ₈ H ₅ NaO ₄ , C ₈ Na ₂ F ₄ O ₄ , C ₁₀ H ₂ Na ₄ O ₈ , A rope type supercapacitor which is an anode containing an anode active material selected from pre-sodiumated forms of C ₁₄ H ₄ O ₆ , C ₁₄ H ₄ Na ₄ O ₈ , and combinations thereof. The rope type supercapacitor of claim 1, wherein the first or second electrically conductive porous rod has a pore of 70% to 99% by volume. The rope type supercapacitor of claim 1, wherein the length of the supercapacitor is greater than 1 m. The rope type supercapacitor of claim 1 wherein the supercapacitor is bent to a radius of curvature of greater than 10 cm. 2. The supercapacitor of claim 1 wherein the supercapacitor is bendable substantially in the shape of an empty space or interior area in a vehicle, the empty space or interior area being a trunk, door, hatch, spare tire area, sub-seat area or under instrument panel. Rope type supercapacitors comprising a region. 28. The rope type supercapacitor of claim 27 wherein said supercapacitor is removable from the vehicle and bendable along the shape of a different void or interior zone. The apparatus of claim 1, wherein the one or more units of the battery comprise clothing, belts, carrying straps, luggage straps, weapon straps, instrument straps, helmets, hats, boots, foot covers, gloves, wrist covers, watch bands, jewelry articles, animals Rope-type supercapacitors contained in collars or animal harnesses. The apparatus of claim 1, wherein the one or more units of the battery comprise clothing, belts, carrying straps, luggage straps, weapon straps, instrument straps, helmets, hats, boots, foot covers, gloves, wrist covers, watch bands, jewelry articles, animals Rope type supercapacitors included in the collar or animal harness in a removable manner. The rope type supercapacitor of claim 1, wherein the battery has an inner radius of the hollow bicycle frame. As a method of manufacturing a rope type supercapacitor,
(e) impregnating a first mixture of the first electrode active material and the first electrolyte into the pores of the first electrically conductive porous rod to form a first electrode;
(f) wrapping or casing the first electrode with a porous separator to form a separator-protected first electrode;
(g) impregnating a second mixture of the second electrode active material and the second electrolyte into the pores of the second electrically conductive porous rod to form a second electrode;
(h) combining the separator protected first electrode and the second electrode together or twisting together to form a braid or twist yarn; And
(i) wrapping or casing the braid or twisted yarn with a protective casing or sheath to form the rope type supercapacitor;
Including,
The first and / or the second electrode active material contains a plurality of particles of carbon material and / or a plurality of graphene sheets, and the plurality of graphene sheets have single layer graphene or 1 to 10 graphene faces respectively. And a hydrophobic layer having graphene, wherein the carbon material or graphene sheet of the plurality of particles has a specific surface area of at least 500 m ² / g as measured in the dry state. 33. The method of claim 32, comprising combining the plurality of first electrodes and / or the plurality of second electrodes to form the supercapacitor, wherein at least one of the electrodes is an anode and at least one is a cathode. Manufacturing method. 33. The method of claim 32, further comprising wrapping or casing the second electrode with a porous separator to form a separator protected second electrode. 35. The method of claim 34, further comprising disposing a third electrolyte between the braid or yarn and the protective sheath. 33. The method of claim 32, wherein the first or second electrode active material contains activated carbon particles or an isolated graphene sheet having a length or width of less than 1 μm for impregnation into the pores of the first or second electrode. The pin sheets are pure graphene, graphene oxide, reduced graphene oxide, graphene fluoride, nitrogenated or nitrogen doped graphene, hydrogenated or hydrogen doped graphene, boron doped graphene, chemically functionalized graphene Or combinations thereof. A method of making a rope type supercapacitor having a length to diameter or length to thickness aspect ratio of greater than 10;
The method is
(e) a first electrode comprising a first electrically conductive rod and a first mixture of first electrode active material and a first electrolyte, wherein the first mixture is deposited on or in the first electrically conductive rod Providing an electrode;
(f) surrounding or casing the first electrode with a porous separator to form a separator-protected first electrode;
(g) impregnating a second mixture of the second electrode active material and the second electrolyte into the pores of the second electrically conductive porous rod to form a second electrode;
(h) combining or twisting the separator protected first electrode and the second electrode in a twisted or helical manner to form a braid or yarn; And
(i) wrapping or casing the braid or yarn with a protective casing or sheath to form the supercapacitor;
Including,
The first active material and / or the second active material contain a plurality of particles of carbon material and / or a plurality of graphene sheets, wherein the plurality of graphene sheets are single layer graphene or 1 to 10 graphene each, respectively. And a hydrophobic layer of graphene having a surface, wherein the carbon material or graphene sheet of the plurality of particles has a specific surface area of at least 500 m ² / g as measured in the dry state. 38. The method of claim 37, further comprising wrapping or casing the second electrode with a porous separator to form a separator protected second electrode. 33. The method of claim 32, wherein the rope-type battery has a first end and a second end, and the method further comprises connecting a first terminal connector to the first electrode, wherein the first terminal connector is At least one metal wire, conductive carbon / graphite fibers, or conductive polymer fibers embedded in, connected to or integral with the first electrode. 40. The method of claim 39, wherein the at least one metal wire, conductive carbon / graphite fiber, or conductive polymer fiber runs approximately from the first end to the second end. 33. The method of claim 32, wherein the first or second electrically conductive porous rod is a metal foam, metal web, metal fiber mat, metal nanowire mat, conductive polymer fiber mat, conductive polymer foam, conductive polymer coated fiber foam, carbon foam Porous selected from graphite foam, carbon aerogel, carbon zero gel, graphene aerogel, graphene foam, graphene oxide foam, reduced graphene oxide foam, carbon fiber foam, graphite fiber foam, exfoliated graphite foam and combinations thereof Method containing a foam. 33. The method of claim 32, wherein the supercapacitor has a rope shape having a length / thickness or length / diameter aspect ratio greater than 10. 37. The method of claim 36, wherein the first or second electrode further comprises a redox pair partner material selected from metal oxides, conductive polymers, organic materials, non-graphene carbon materials, inorganic materials, or combinations thereof. Wherein said partner material is combined with graphene or activated carbon to form a redox pair for pseudocapacitance. The method of claim 43, wherein the metal oxide is RuO ₂ , IrO ₂ , NiO, MnO ₂ , VO ₂ , V ₂ O ₅ , V ₃ O ₈ , TiO ₂ , Cr ₂ O ₃ , Co ₂ O ₃ , Co ₃ O ₄ , PbO ₂ , Ag ₂ O and combinations thereof. The method of claim 43, wherein the inorganic material is selected from metal carbides, metal nitrides, metal borides, metal dichalcogenides, and combinations thereof. 45. The method of claim 43, wherein the metal oxide or inorganic material is niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, vanadium, chromium, cobalt, manganese in the form of nanowires, nanodisks, nanoribbons, or nanoplates. , Iron, or nickel oxides, dichalcogenides, trichalcogenides, sulfides, selenides, or tellurides. 45. The method of claim 43, wherein the inorganic material is bismuth selenide, bismuth telluride, transition metal dichalcogenide, transition metal trichalcogenide, niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, cobalt, manganese, iron Sulfides, niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, cobalt, manganese, iron, nickel or transition metals, selenides, niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, Selected from nanodisks, nanoplates, nanocoats or nanosheets of inorganic materials selected from the group comprising cobalt, manganese, iron, nickel or transition metals, tellurides, boron nitride, and combinations thereof; The disk, plate, or sheet has a thickness of less than 100 nm. 33. The method of claim 32, wherein the first or second electrode active material is bismuth selenide, bismuth telluride, transition metal dichalcogenide, transition metal trichalcogenide, niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, Sulfides of cobalt, manganese, iron, nickel or transition metals, niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, cobalt, manganese, iron, nickel or transition metals selenide, niobium, zirconium, molybdenum, hafnium, tantalum Contains nanodisks, nanoplates, nanocoats or nanosheets of inorganic materials selected from the group comprising, tungsten, titanium, cobalt, manganese, iron, nickel or transition metals, tellurides, boron nitride, and combinations thereof The disk, plate, coating or sheet has a thickness of less than 100 nm and a specific surface area of at least 200 m ² / g as measured in the dry state. 33. The method of claim 32, wherein the first or second electrically conductive porous rod has 70% to 99% by volume pores. 33. The method of claim 32, wherein step (a) comprises the steps of: (i) continuously feeding the electrically conductive porous rod to the first electrode active material impregnation zone comprising an interconnected electron conductive path and having at least one porous surface; And (ii) impregnating the first mixture from the at least one porous surface into the electrically conductive porous rod to form the first electrode. 51. The method of claim 50, wherein step (a) continuously or as desired provides the first mixture to the at least one porous surface through spraying, printing, coating, casting, conveyor film transfer, and / or roller surface transfer. Intermittently delivering. 33. The method of claim 32, wherein step (c) comprises: (i) continuously supplying the electrically conductive porous rod to the impregnation zone of the second electrode active material comprising an interconnected electron conducting path and having at least one porous surface ; And (ii) impregnating the second mixture from the at least one porous surface into the electrically conductive porous rod to form the second electrode. 53. The method of claim 52, wherein step (c) comprises continuously or as desired the second mixture on the at least one porous surface through spraying, printing, coating, casting, conveyor film transfer, and / or roller surface transfer. Intermittently delivering. 33. The method of claim 32, wherein step (b) comprises forming the porous separator-protected first electrode in a coiled or helical fashion with the porous separator band surrounding the first electrode. 33. The method of claim 32, wherein step (b) comprises spraying an electrically insulating material to form a porous shell structure surrounding the first electrode to cover the first electrode to form the porous separator-protecting structure. .

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