KR20180092168A - lithium ion capacitor and making method therefor - Google Patents

Abstract

The present invention relates to a lithium-ion capacitor which can exhibit electric double layer performance simultaneously with occlusion and discharge of lithium ions at a cathode to increase a discharge voltage as well as increase the density of electric energy, thereby being effectively used as a backup power source for an electronic device; which has a cathode sheet, an anode sheet, a separator, and a non-electrolytic electrolyte provided in a space between a case and a cap, and has the cathode sheet including a cathode material containing a lithium compound to be implementable without installing an additional lithium metal, thereby allowing the lithium ions to be doped safely and efficiently while being produceable into various shapes and forms, and simplifying a manufacturing process; which can be configured to produce the cathode material through a dry process during a cathode material manufacturing process to prevent the lithium compound from being oxidized and eluted by oxygen and water when the cathode material is produced through a wet process, thereby improving achieving performance such as a long life, high output, and high-energy density; and which allows a first mixing process for mixing a conductor formed of the cathode material, activated carbon, and the lithium compound to be performed under a nitrogen atmosphere to block a preliminary reaction of the lithium compound efficiently, thereby efficiently blocking a deterioration in battery performance in advance.

Description

[0001] The present invention relates to a lithium ion capacitor and a manufacturing method thereof,

The present invention relates to a lithium ion capacitor and a method of manufacturing the same, and more particularly, to a lithium ion battery and an electric double layer capacitor (EDLC) To a lithium ion capacitor capable of miniaturization because of its high energy density and its manufacturing method.

A capacitor is a device that generates a capacitance by supplying a direct current voltage in a state in which two electrode plates are opposed to each other and accumulating electricity in each electrode. An electric double layer capacitor (EDLC) ), Aluminum electrolytic capacitors, multilayer ceramic capacitors, and super capacitors.

Recently, as the technology of digital devices and electronic devices such as a smart phone has rapidly developed, there has been an increase in demands and necessities for miniaturization, high performance, and high performance capacitors. Accordingly, a lithium ion capacitor having a high energy density (LIC, Lithium Ion Capacitor).

Particularly, coin type capacitors can be manufactured in a compact size and have excellent performance, so that the field of use and demand are increasing rapidly.

The coin type lithium ion capacitor can combine the advantages of a lithium ion battery having a high capacity and a high density energy and the advantages of an electric double layer capacitor (EDLC) having an excellent output. Specifically, And a carbonaceous material that can be desorbed. In addition, lithium ion is pre-doped into an anode active material to provide a high operating voltage per cell and a high energy density of 2 to 3 as compared with a conventional electric double layer capacitor (EDLC). .

In this case, the conventional coin-type lithium ion capacitor essentially performs a lithium doping process for inducing insertion and desorption of lithium by injecting lithium into the capacitor at the time of manufacturing so as to have high density and high capacity.

Various methods and techniques have been studied for the lithium doping process. However, a lithium metal is deposited on a negative electrode active material such as graphite and then a potential difference is generated between the lithium metal and the negative active material through a short, So that the molten metal can flow in.

However, since the conventional lithium doping system is configured such that lithium is doped into the anode active material through electrical shorting, the safety is deteriorated and precise control of the amount of doping of lithium is required. Thus, the process is complicated, and the anode active material The manufacturing cost is increased.

In addition, since the conventional coin-type lithium ion capacitor can be manufactured only in the form of an aluminum pouch due to the installation of lithium metal, the manufacturing process is complicated and has structural limitations that can not be manufactured in various forms.

1 is a side cross-sectional view showing a coin type lithium ion capacitor disclosed in Korean Patent No. 10-1056512 (entitled: Lithium ion capacitor and a manufacturing method therefor) filed by the present applicant and registered as a patent.

The coin type lithium ion capacitor 200 of FIG. 1 includes a lower cap 201 and an upper cap 202, which is coupled to an upper portion of the lower cap 201 and forms a space therein when coupled, A gasket 203 installed at a joint portion between the upper cap 202 and the lower cap 201 to seal the space, an anode 204 bonded to the bottom surface of the lower cap 201, A cathode 205 adhered to the upper surface of the anode 202 and a separator 206 provided between the anode 204 and the cathode 205.

The cathode 205 is made of a lithium metal alloy capable of intercalating and deintercalating lithium, oxides containing lithium such as LixMnyOz, LixTiyOz and LixCoyOz, or carbon materials such as graphite, hard carbon and soft carbon in which lithium ions are stored.

In the first conventional art 200 configured as described above, lithium ions are stored and discharged from the cathode 205, and the electric double layer performance is exhibited at the anode, so that the electric energy density is high and the discharge voltage is high.

However, in the first prior art (200), a lithium doping process for doping lithium into the anode active material must be performed at the time of manufacturing the cathode 205. This lithium doping process is a process of doping lithium into the anode active material The safety is deteriorated and precise control of the amount of lithium doping is required, so that the process is complicated and cumbersome. In order to accommodate a large amount of lithium, the anode active material is formed into a multi-annular shape.

1) lithium metal can be added to the cathode active material to efficiently supply lithium without a separate lithium metal deposition and doping process, 2) a coin-type lithium ion (lithium ion battery) The study of capacitors is urgent.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a lithium ion secondary battery which is capable of storing and discharging lithium ions in an anode and exhibiting an electric double layer performance, The present invention provides a lithium ion capacitor which can be effectively used as a backup power source and a method of manufacturing the same.

Another object of the present invention is to provide a positive electrode sheet, a negative electrode sheet, a separator and a non-electrolytic electrolyte in a space between a case and a cap, wherein a lithium metal is contained in a positive electrode active material, The present invention provides a lithium ion capacitor which can be manufactured in various shapes and shapes without being damaged, can be safely and efficiently doped with lithium ions, and can be manufactured easily, and a method for manufacturing the same.

Still another object of the present invention is to provide a lithium ion capacitor capable of remarkably improving the performance of a using voltage and self discharge by being constituted to produce a positive electrode active material through a wet process in the process of manufacturing a positive electrode active material, will be.

In addition, another object of the present invention is to provide a positive electrode active material which is capable of preventing the lithium compound from being oxidized and eluted by oxygen and water when manufactured by a wet process, Accordingly, it is an object of the present invention to provide a lithium ion capacitor and a method of manufacturing the lithium ion capacitor capable of improving the performance of high life, high output and high energy density.

In addition, another object of the present invention is to provide a cathode active material which is capable of effectively preventing the pre-reaction of a lithium compound by performing a primary mixing process for mixing a conductive agent, an activated carbon and a lithium compound in a nitrogen atmosphere in a dry process of a cathode active material, And a method for manufacturing the lithium ion capacitor.

Further, another object of the present invention is to provide a lithium ion capacitor capable of more precisely blocking a preliminary reaction of a lithium compound by applying a binder for binding a conductive agent, an activated carbon and a lithium compound in a cathode active material dry process, And a method for producing the same.

Another problem to be solved by the present invention is to provide a method for manufacturing a positive electrode active material, which comprises mixing a conductive agent, an activated carbon, a lithium compound and a binder by a secondary mixer using a mixer equipped with a high- And a method of manufacturing the lithium ion capacitor.

In order to solve the above-described problems, the present invention provides a lithium ion secondary battery comprising a case which is a cathode current collector, a case which is a cathode current collector, a space is formed therein and a cathode sheet, a cathode sheet, a separator, In the capacitor, the positive electrode active material forming the positive electrode sheet 3 to 10% by weight of the conductive agent; 3 to 10% by weight of the binder; 40 to 75 wt% of the activated carbon; And 5 to 50% by weight of the lithium compound.

In the present invention, the cathode active material is first kneaded after being charged into the Kneader by 3 to 10% by weight of the conductive agent, 40 to 75% by weight of the activated carbon and 5 to 50% by weight of the lithium compound, It is preferable that the mixture is prepared by kneading the mixture with a solvent having a first kneading completion and then kneading with a binder having a concentration of 40% by the second kneading and completing the second kneading.

Also, in the present invention, the positive electrode active material for forming the positive electrode sheet is prepared by mixing the conductive agent, the activated carbon, and the lithium compound in a primary mixing state in a nitrogen purging environment to block the reaction of the lithium compound with oxygen, It is preferable that a solid-state binder is added to the mixture and then a second-mixed, second-mixed mixture is produced by hot pressing.

In the present invention, the pulverizing equipment applied to the secondary mixing includes a high-speed rotary knife which is a rotating blade, and rotates the high-speed rotary knife at a speed of 3000 to 5000 rpm, It is preferable to bind the conductive agent, the activated carbon and the lithium compound by being linearly stretched by a rotating knife.

Also, in the present invention, it is preferable that the activated carbon is coated with carbon nanotubes (carbon nanotubes) or graphite on its surface.

In the present invention, it is preferable that the lithium compound is at least one of Li2MoO3, Li2MnO3, Li2NiO2, Li2PtO3, Li2IrO3, Li2RuO3, Li2SnO3, Li2ZrO3, Li5FeO4, Li6CoO4 and Li5MnO4.

In the present invention, the negative electrode active material for forming the negative electrode sheet preferably contains 3 to 10% by weight of a conductive agent, 3 to 10% by weight of a binder and 80 to 90% by weight of a soft carbon.

In the present invention, the binder may be at least one selected from the group consisting of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyvinyl pyrrolidone, polyvinyl chloride (PVC), polyethylene (PE), styrene butadiene rubber ), Carboxymethyl cellulose (CMC), and fluorinated rubbers are preferably selected and mixed and used.

In the present invention, the electrolytic solution includes a solute capable of intercalating and deintercalating lithium ions, a solute capable of expressing an electric double layer capacity, and a solvent, and the solute expressing the electric double layer capacity of the electrolyte is tetraethylammonium hexafluorophosphate (Tetraethylammonium hexafluorophosphate, (C2H5) 44NPF6), tetraethylammonium tetrafluoroborate (C2H5) 44NPF4, tetraethylammonium bis (trifluoromethanesulfonyl) imide, (C2H5) 44N- N (CF3SO2) 2, Et4NTFSI, TEATFSI), triethylmethylammoniumbis (trifluoromethanesulfonyl) imide, (C2H5) 3CH3N-N (SO2CF3) 2, Et3MeNTFSI, TEMATFSI) Triethylmethylammoniumbis (trifluoromethanesulfonyl) imide, (CH4 (C2H5) 3N-N (CF3SO2) 2), methyl ammonium bis (trifluoromethanesulfonyl) imide At least one of lithium-perchlorate, lithium perchlorate, lithium perchlorate, lithium perchlorate, lithium perchlorate, lithium perchlorate, and lithium perchlorate is selected and mixed. LiClO4), lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium trifluoromethanesulfonate (LiCF3SO3, LiTFS), bistrifluoromethylsulfonylimide lithium At least one of lithium bis (trifluoromethanesulfonyl) imide, LiN (CF3SO2) 2, LiTFSI, bispentafluoroethanesulfonylimide, LiN (SO2C2F5) 2 and LiBETI (DEC), Ethylmethylcarbonate (EMC), γ-Butyrolactone (DEC), Ethylmethyl carbonate (EC), Ethylene carbonate (EC), Butylene carbonate (BC), Vinylene carbonate (VC), VinylEthyleneCarbonate N-Dimethyl Formamide (DMF), 1,3-Dimethyl-2-Imidazolidinone (DMI), N, N-Dimethyl Acetamide (DMAC) It is preferable that at least one of at least one of sulfolane (SL), dimethyl sulfoxide (DMSO), acetonitrile (AN), propionitrile (PN) and tetrahydrofuran (THF) is selected and mixed.

According to the present invention having the above-mentioned problems and solutions, lithium ion storage and discharging are performed at the anode and the electric double layer performance is manifested, so that not only the electric energy density is high but also the discharge voltage is increased, have.

According to the present invention, a positive electrode sheet, a negative electrode sheet, a separator, and a non-electrolytic electrolyte are provided in a space between the case and the cap, and a lithium compound is contained in the positive electrode active material so that a separate lithium metal is not required. So that it can be manufactured in various shapes and forms, and lithium ions can be doped safely and efficiently, and the manufacturing process can be simplified.

According to the present invention, the positive electrode active material is manufactured through the wet process in the process of manufacturing the positive electrode active material, so that the performance of the use voltage and the self discharge can be remarkably improved.

According to the present invention, since the cathode active material is manufactured through the dry process in the cathode active material manufacturing process, when the cathode active material is manufactured by the wet process, oxidation and elution of the lithium compound by oxygen and water can be prevented, , The performance of high power and high energy density can be improved.

According to the present invention, in the cathode active material dry process, the primary mixing process for mixing the conductive agent, the activated carbon and the lithium compound of the cathode active material is performed in a nitrogen atmosphere to more effectively block the preliminary reaction of the lithium compound, It is possible to effectively prevent it in advance.

In addition, according to the present invention, a binder for binding a conductive agent, an activated carbon and a lithium compound in a cathode active material dry process can be applied as a solid phase rather than a liquid phase, thereby more precisely blocking a lithium compound.

In addition, according to the present invention, by mixing a conductive agent, an activated carbon, a lithium compound and a binder in a secondary mixer using a mixer equipped with a high-speed rotary knife during the cathode active material dry process, the binder growth (softening) And to provide a method for manufacturing the lithium ion capacitor.

1 is a side cross-sectional view showing a coin type lithium ion capacitor disclosed in Korean Patent No. 10-1056512 (entitled "Lithium ion capacitor and a manufacturing method therefor) filed by the present applicant and registered as a patent.
2 is a configuration diagram illustrating a lithium ion capacitor according to an embodiment of the present invention.
3 is a process flow chart showing a wet process method of the positive electrode sheet of FIG.
Fig. 4 is a process flow chart showing the steps of producing the lithium compound of Fig. 3; Fig.
5 is a process flow chart showing a wet process of the positive electrode sheet of FIG.
FIG. 6 (a) is an exemplary view showing the state of the mixture before the binder of the present invention grows, (b) is an exemplary view showing the state of the mixture when the binder is grown in a predetermined manner, And shows the state of the mixture when grown.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

2 is a configuration diagram illustrating a lithium ion capacitor according to an embodiment of the present invention.

The lithium ion capacitor 1 according to an embodiment of the present invention is characterized in that 1) a lithium compound containing lithium is added to a cathode material forming a cathode so that lithium ions are intercalated and deintercalated from the cathode active material It is possible to safely and efficiently dope lithium ions into the cathode electrochemically without installing a separate lithium metal, and 2) optimally adjust the content of the conductive agent, the binder, the lithium compound, and the activated carbon in the cathode active material in the wet process And 3) a positive electrode active material is produced through a dry process to prevent lithium from reacting with water, thereby exhibiting a high life, high output and high energy density performance .

2, the lithium ion capacitor 1 includes a case 2 as a positive electrode current collector, a cap 3 as a current collector, a gasket 4, a positive electrode sheet 5, A sheet 6, a separator 7, a non-electrolytic electrolytic solution 8, and conductive adhesives 11 and 12.

 The case 2 is composed of a disk-shaped bottom wall 21 and a vertical wall 23 upwardly bent from the outer edge of the bottom wall 21 and connected along an arc.

In addition, the case 2 is formed with an opening at an upper portion thereof by a vertical wall 23, and a receiving space is formed therein.

The case 2 is formed of a stainless steel, copper, nickel, titanium, tantalum, niobium, or an alloy thereof as a current collector of the anode.

The cap 3 is composed of an upper plate 31 for sealing the upper opening of the case 2 and a side wall 33 bent downward from the outer edge of the upper plate 31 and connected along an arc.

The upper plate 31 of the cap 3 is formed of a circular plate having an outer diameter smaller than that of the bottom wall of the case 2. [

The cap 3 is coupled with the case 2 so that the upper plate 31 closes the upper opening of the case 2 when the coupling is engaged and the side wall 33 is located inside the vertical wall 23 of the case 2 And is coupled with the case 2 so as to be disposed.

The cap 3 is a current collector of a negative electrode and is formed of any one of stainless steel, copper, nickel, titanium, tantalum and niobium, or an alloy thereof.

The gasket 4 is installed so as to be inserted into the space in which the vertical wall 23 of the case 2 and the side wall 33 of the cap 3 are opposed to each other when the case 2 and the cap 3 are engaged Thereby sealing the inner space.

The gasket 4 may be made of polypropylene (PPS), polyether ether ketone (PEEK), nylon, etc. Specifically, the gasket 4 may be made of an engineering plastic (Engineering plastics).

The negative electrode sheet 6 is made of a negative electrode active material and one surface thereof is attached to the upper plate 31 of the cap 3 by the conductive adhesive agent 12.

The negative electrode active material for forming the negative electrode sheet 6 is composed of 3 to 10% by weight of a conductive agent, 3 to 10% by weight of a binder and 80 to 90% by weight of a soft carbon.

The negative electrode active material forming the negative electrode sheet 6 is made of a graphite-based material such as soft carbon, hard carbon, natural graphite or the like. In this case, the surface of the graphite-based material of the anode active material is coated with 1 to 20 wt% of a conductive material such as carbon nano-tube and graphite, thereby enhancing electrical conductivity.

The negative electrode sheet 6 is formed to have a diameter of approximately 12.5 mm and a thickness of 0.5 mm.

One side of the positive electrode sheet 5 is attached to the bottom wall 21 of the case 2 by means of the conductive adhesive 11.

The positive electrode sheet 5 is formed to have a diameter of approximately 12.5 mm and a thickness of 1.0 mm.

The positive electrode active material for forming the positive electrode sheet 5 is composed of 3 to 10% by weight of a conductive agent, 3 to 10% by weight of a binder, 5 to 50% by weight of a lithium compound and 40 to 75% by weight of activated carbon.

The cathode active material may also be prepared by 1) a wet process and 2) a dry process.

First, 1) Wet process will be described. In the present invention, the content of the conductive agent, the binder, the lithium compound and the activated carbon in the cathode active material production process is optimally controlled to remarkably improve the battery performance such as lifetime, output, capacity and self- Such a cathode active material wet process will be described in detail later with reference to FIG.

In addition, since the lithium compound generally has a property of lowering the performance of a capacitor by generating a reaction such as oxidation and elution when exposed to oxygen and water at the time of production, The anode sheet 5 is formed in a dry process in consideration of the characteristics of the anode and the cathode so that the reaction of the lithium compound by oxygen and water is thoroughly blocked so that the life, output and energy density of the capacitor The manufacturing process of the cathode active material will be described in detail later with reference to FIGS. 4 to 6. FIG.

In other words, the positive electrode active material of the positive electrode sheet 5 is subjected to a wet process so that 3 to 10 wt% of a conductive agent, 3 to 10 wt% of a binder, 5 to 50 wt% of a lithium compound, and 40 to 75 wt% (IPA, isopropyl alcohol), kneaded, and then rolled by a high-temperature roll to form a sheet.

The positive electrode active material of the positive electrode sheet 5 is mixed and dispersed through a dry process by 3 to 10% by weight of the conductive agent, 3 to 10% by weight of the binder, 5 to 50% by weight of the lithium compound and 40 to 75% And a sheet is formed through a rolling process by a high-temperature roll.

The cathode sheet 5 produced through the wet process or the dry process is attached to the bottom wall 21 of the case 2 by the conductive adhesive 11.

The conductive agent is contained in an amount of 3 to 10% by weight based on the total weight in the wet process or the dry process to form the anode. At this time, if the content is less than 3% by weight, the content of the conductive agent is excessively decreased and the electrode efficiency is lowered. If the content is more than 10% by weight, the electrode efficiency is increased but the content of activated carbon and lithium oxide is decreased. The problem of falling occurs.

The conductive agent is carbon black having excellent conductivity such as Denka black, Super p, Ketjenblack and the like in a wet process or a dry process. Specifically, Ketjenblack ). In the present invention, the conductive material is carbon black. However, it is natural that the conductive material may be a metal filler such as silver (Ag), palladium (Pd) or the like which is commonly used in the electrode composition.

The binder participates in the mechanical mixing of the conducting agent, the lithium compound and the activated carbon to determine the rheological properties which are characteristic of deformation and flow of these mixtures.

Further, the binder is added to the mixture after the conductive agent, the lithium compound, and the activated carbon are mixed with the solvent and kneaded in the wet process. That is, the binder is mixed after the secondary kneading step (S250) of FIG. 3 to be described later, whereby the binder is uniformly distributed on the surface of the lithium compound, thereby giving an adhesive force to the mixture of the conductive agent, the lithium compound, .

Further, the binder is formed into a solid phase during the dry process. In this case, when the binder is formed into a liquid phase, there arises a problem that the lithium of the lithium compound leaks out in response to the solvent when the mixture is mixed during the dry process of the cathode active material. Therefore, in the present invention, The reaction can be thoroughly prevented, thereby preventing and improving the problem that the lifetime, capacity and energy density of the lithium ion capacitor 1 are lowered due to the preliminary reaction of lithium.

The binder is contained in an amount of 3 to 10% by weight based on the positive electrode active material. If the content is less than 3% by weight, the adhesive strength of the cathode active material is lowered. If the content is more than 10% by weight, the content of the binder is excessive and the electrode resistance Rdc of the electrode increases, .

The binder may also be selected from the group consisting of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyvinyl pyrrolidone, polyvinyl chloride (PVC), polyethylene (PE), styrene butadiene rubber (SBR) Cellulose (CMC), and fluorinated rubber may be selected and mixed to be used. Specifically, it is preferable that polytetrafluoroethylene (PTFE) is used.

The lithium compound is an oxide containing lithium of LixMnyOz, LixTyOz, and LixCoyOz capable of intercalating and deintercalating lithium upon charging and discharging. It is oxidized and reduced during charging and discharging to store energy through the movement of lithium ions to increase the capacity of the capacitor . At this time, since the lithium compound is adsorbed on the surface of activated carbon by the physical properties of the activated carbon, the output characteristic of the capacitor is remarkably increased.

The lithium compound is contained in an amount of 5 to 50% by weight based on the weight of the cathode active material. If the content of the lithium compound is less than 5% by weight, the amount of lithium doping into the negative electrode active material is less than the threshold value, so that the capacity and the energy density do not fall within the design range. If the content exceeds 50% by weight, So that the charge / discharge efficiency, lifetime characteristics, and lithium ion recovery rate are lowered.

The lithium compound may be any one of Li2MoO3, Li2MnO3, Li2NiO2, Li2PtO3, Li2IrO3, Li2RuO3, Li2SnO3, Li2ZrO3, Li5FeO4, Li6CoO4, and Li5MnO4, or may be formed by mixing at least two or more Li6CoO4 or Li2NiO2 .

Activated carbon is a black carbon particle that is produced by a combustible material such as a coconut shell through carbonization at about 500 ° C and activation (activation) at about 900 ° C. In a broad sense, Which means that the carbonaceous function is improved by changing to a state in which chemical reaction or crystal lattice is likely to occur.

That is, the activated carbon is formed of carbonaceous material having a large surface area and strong adsorption on the surface, which can store energy by surface adsorption, thereby increasing the charging / discharging rate and increasing the high efficiency output characteristic of the capacitor by adsorbing and desorbing lithium ions through physical reaction .

Also, it is preferable that the activated carbon is made of at least one of activated carbon having a specific surface area of 300 to 3,000 m 2 / g carbonized by carbonizing a hardwood, palm tree, coconut, petroleum pitch, phenol (synthetic resin) Do.

The activated carbon is contained in an amount of 40 to 75% by weight based on the total weight of the cathode active material. If the content of the activated carbon is less than 40% by weight, the charge / discharge efficiency, lifetime characteristics and lithium ion recovery rate are inferior. If the content exceeds 75% by weight, the content of the lithium compound is excessively low, Is less than the threshold value, the capacity and the energy density do not fall within the design range.

In addition, the activated carbon is formed with a particle diameter of 1 to 30 mu m to increase the dispersibility of the lithium compound and the conductive agent.

The activated carbon preferably has a specific surface area of 200 to 3,000 m 2 / g of activated carbon.

In addition, the surface of activated carbon can be coated with 1 to 20 wt% of a conductive material such as carbon nano-tube and graphite to improve electrical conductivity.

2, the separator 7 is provided between the positive electrode sheet 5 and the negative electrode sheet 6 in such a manner that both surfaces thereof are in contact with each other.

The separator 7 is preferably made of one or more of glass fiber, PPS, PEEK nonwoven fabric having a heat resistance of 200 ° C or more, and stacking them.

The non-electrolytic electrolytic solution 8 is injected into a space between the case 2 and the cap 3 to provide a pathway for lithium ions, and a solute capable of intercalating and deintercalating lithium ions and a solute for expressing the electric double- .

The solute which expresses the electrical double layer capacity of the electrolyte is tetraethylammonium hexafluorophosphate (C2H5) 44NPF6), tetraethylammonium tetrafluoroborate (C2H5) 44NPF4), tetraethylammonium bis (trifluoro Triethylmethylammoniumbis (trifluoromethanesulfonyl) imide, (C2H5) 44N-N (CF3SO2) 2, Et4NTFSI, TEATFSI), triethylmethylammoniumbis (trifluoromethanesulfonyl) imide, (C 2 H 5) 3 N-N (CF 3 SO 2) 2), triethylmethylammoniumbis (trifluoromethanesulfonyl) imide, (CH 4 (C 2 H 5) 3 N-N (SO 3 CF 2) , And spiro- (1,1 ') -bipyrrolidinium tetrafluoroborate (SPB-BF4) are selected and mixed and used.

The solute capable of intercalating and deintercalating lithium ions in the electrolyte is preferably lithium perchlorate (LiClO4), lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), 3-fluoromethylsulfonic acid Lithium bis (trifluoromethanesulfonyl) imide, LiN (CF3SO2) 2, LiTFSI), bis (pentafluoroethanesulfonylimide) lithium bis pentafluoroethanesulfonylimide, LiN (SO2C2F5) 2, LiBETI) are selected and mixed to be used.

In addition, the solvent of the electrolytic solution can be selected from the group consisting of Propylene Carbonate (PC), Ethylene Carbonate (EC), Butylene Carbonate (BC), Vinylene Carbonate (VC), VinylEthylene Carbonate (VEC), Dimethyl Carbonate (DMC), Diethyl Carbonate N-Dimethyl Formamide (DMF), 1,3-Dimethyl-2-Imidazolidinone (DMI), N, N-Dimethyl Acetamide (DMAC) At least one or more selected from the group consisting of sulfolane (SL), dimethyl sulfoxide (DMSO), acetonitrile (AN), propionitrile (PN) and tetrahydrofuran (THF)

That is, the lithium ion capacitor 1 of the present invention has a space formed therein when the case 2 and the cap 3 are coupled, and the positive electrode sheet 5, the negative electrode sheet 6, and the separator 7 are formed in the internal space, Respectively.

At this time, a cathode is a positive electrode including a housing 2 and a positive electrode sheet 5, and a negative electrode includes a cap 3 and a negative electrode sheet 6 which are current collectors (Negative electrode).

3 is a process flow chart showing a wet process method of the positive electrode sheet of FIG.

The wet process S200 of the cathode sheet of FIG. 3 includes a step of preparing a conductive agent S210, an activated carbon preparation step S220, a lithium compound manufacturing step S230, a binder preparation step S240, a primary kneading step S230, A second rolling step S290, a second rolling step S290, a third rolling step S270, a first rolling step S280, a second rolling step S290, a cutting step S250, a second kneading step S260, a third kneading step S270, Step S300.

The conductive agent preparation step S210 is a process step of preparing a conductive agent (powder) which is carbon black having excellent conductivity such as denka black, tbvjbl (Super p), Ketjenblack and the like.

The conductive agent by the conductive agent preparing step (S210) is contained in an amount of 3 to 10% by weight based on the total weight of the cathode active material. At this time, if the content of the conductive agent is less than 3% by weight, the content is excessively decreased and the electrode efficiency is lowered. If the conductive agent content is more than 10% by weight, the electrode efficiency is increased but the content of activated carbon and lithium oxide is decreased, Lt; / RTI >

The activated carbon preparation step S220 is a process step for preparing activated carbon. Activated carbon is carbonized by hard wood, palm tree, coconut, petroleum pitch, phenol (synthetic resin) to have a specific surface area of 300 to 3000 m2 / g or at least one of these activated carbons. Since the process for producing activated carbon is a commonly used technique, a detailed description thereof will be omitted.

Also, the activated carbon by the activated carbon preparation step (S220) is contained in an amount of 40 to 75% by weight with respect to the cathode active material. If the content of activated carbon is less than 40 wt%, the charge / discharge efficiency, lifetime characteristics, and lithium ion recovery rate are inferior. If the content of activated carbon is more than 75 wt%, the content of lithium compound becomes excessively low, So that the capacity and the energy density do not fall within the design range.

The lithium compound production step (S230) is a process step of producing a lithium compound capable of absorbing and releasing lithium ions during charging and discharging to improve capacity and output characteristics of the capacitor.

Fig. 4 is a process flow chart showing the steps of producing the lithium compound of Fig. 3; Fig.

As shown in FIG. 4, the lithium compound preparation step (S230) may include a lithium salt solution preparation step (S231) for preparing a lithium salt solution and a lithium salt solution prepared by a lithium salt solution preparation step (S231) A step (S232) of producing an intermediate complex oxide by decomposing the intermediate complex oxide (S232) and a step (S232) of mixing an organic acid salt including the powder lithium of the intermediate complex oxide produced by the intermediate production step (S232) S233) and a mixing step (S43) to heat-treat the mixture to produce a lithium compound (S234).

In this case, in FIG. 4, for convenience of explanation, the intermediate preparation step (S232) has been described as decomposing the lithium salt solution through the spray pyrolysis method. However, the decomposition method is not limited to this, and the solid phase reaction method, It will be appreciated that various processes may be applied.

The binder preparation step S240 is a process step of preparing a binder and the binder is selected from the group consisting of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyvinyl pyrrolidone, polyvinyl chloride (PVC) At least one of polyethylene (PE), styrene butadiene rubber (SBR), carboxymethyl cellulose (CMC) and fluorinated rubber is selected and mixed.

In detail, the binder preparation step (S240) was performed by adding polytetrafluoroethylene (PTFE) to the solvent and mixing them at a concentration of 40%.

The binder prepared by the binder preparation step (S240) is contained in an amount of 3 to 10% by weight based on the positive electrode active material. If the content of the binder is less than 3% by weight, the adhesive force of the positive electrode active material decreases. If the content of the binder is more than 10% by weight, the content of the binder is excessive and the electrode resistance Rdc of the electrode increases. do.

The primary kneading step S250 may include the step of preparing the conductive agent by the conductive preparation step S210 at a concentration of 3 to 10 wt%, the step of preparing the activated carbon at the step S220 of 40 to 75 wt% S230) is added to a kneader (Kneader) for kneading, followed by stirring at a speed of 10 to 50 rpm for 5 to 20 minutes to mix the lithium compound.

The second kneading step S260 is a step of injecting a solvent into a kneader which has undergone a first kneading step S250 and stirring the mixture at a speed of 10 to 50 rpm for 5 to 10 minutes to be.

At this time, the solvent may be pure water (H2O) mixed with IPA (isopropyl alcohol), prostaglandin (PG), polyethylene glycol (PEG) or the like, but is not limited thereto. It is preferable to use icosapentaenoic acid (IPA).

In the third kneading step S270, a binder (concentration of 40%) by the binder preparation step S240 of 3 to 10% by weight is added to the kneader that has performed the second kneading step S260 And the mixture is stirred for 10 to 30 minutes at a speed of 10 to 50 rpm.

Also, in the third kneading step (S270), a dispersion stabilizer may be added together when the binder is added, and polyvinylpyrrolidone (PVP) may be sieved as a dispersion stabilizer for the flexibility and high mechanical strength of the electrode . In order to stabilize the dispersion, it is necessary to prevent agglomeration due to collision between particles. In order to prevent such aggregation, polyvinyl pyrrolidone (PVP) is used as a dispersion stabilizer, and polyvinyl pyrrolidone (PVP) It adsorbs on the surface to give charge to the particles, and it acts as a three-dimensional protective film to prevent aggregation of particles.

The primary rolling step S280 is a process step of pressing the mixed and dispersed mixture by a high-temperature vertical roll by a third-order kneading step S270, and a secondary rolling step S290 Is a process step of manufacturing the above-described anode sheet 5 by pressing the mixture pressed by the primary rolling step S280 using a low-temperature horizontal roll.

In the cutting step S300, the cathode sheet 5 manufactured by the second rolling step S290 is cut into a disk shape having a diameter of about 12.5 mm and a thickness of 1.0 mm by using a known cutting equipment Process step.

As described above, the positive electrode sheet 5 according to one embodiment of the present invention is produced by the wet process of FIGS. 3 and 4 in which the binder 3 to 10% by weight, the binder 3 to 10% 50% by weight of activated carbon, and 40 to 75% by weight of activated carbon. Thus, battery performance such as lifetime, output, capacity and self-discharge can be remarkably improved and energy density can be made small, It is possible to expect a higher voltage and a capacity more than twice as high as that of a doll electric double layer capacitor (EDLC).

5 is a process flow chart showing a wet process of the positive electrode sheet of FIG.

The wet process (S400) of the positive electrode sheet of FIG. 5 includes the steps of preparing a conductive agent (S410), preparing activated carbon (S420), preparing a lithium compound (S430), preparing a binder (S440) A grinding and binder growing step S460, a dispersing step S470, a first rolling step S480, a second rolling step S490, and a cutting step S500.

The conductive agent preparing step S410, the activated carbon preparing step S420 and the lithium compound preparing step S430 are the same as the conductive agent preparing step S210, the activated carbon preparing step S220, the lithium compound preparing step S230). ≪ / RTI >

The binder preparing step S440 is a process step of preparing a solid binder. 3, the binder preparation step S240 of FIG. 3 is configured to add and mix polytetrafluoroethylene (PTFE) to a solvent to prepare the binder at a concentration of 40%. However, in the present invention, the binder may be a solid- Is applied.

The binder may be selected from the group consisting of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyvinyl pyrrolidone, polyvinyl chloride (PVC), polyethylene (PE), styrene butadiene rubber (SBR) Cellulose (CMC), and fluorinated rubber are selected and mixed.

That is, the binder preparing step S440 can solve the problem that the lithium compound reacts with the solvent during the crushing and binder growing step (S460) to reduce the lifetime, capacity and energy density of the capacitor by applying the binder to the solid phase.

Also, the binder by the binder preparation step (S440) is contained in an amount of 3 to 10% by weight based on the positive electrode active material. If the content of the binder is less than 3% by weight, the adhesive force of the positive electrode active material decreases. If the content of the binder is more than 10% by weight, the content of the binder is excessive and the electrode resistance Rdc of the electrode increases. do.

The powder mixing step S450 is performed by the conductive agent preparing step S410 by the conductive agent 3 to 10% by weight, the activated carbon preparing step S420 by the activated carbon 40 to 75% by weight, and the lithium compound preparing step S430 And 5 to 50% by weight of the lithium compound thus prepared are mixed in a nitrogen atmosphere.

That is, in the powder mixing step S450, the chamber in which the mixing is performed is formed in a vacuum state, and then the conductive agent, the activated carbon and the lithium compound are mixed through nitrogen purging to thoroughly block the phenomenon that the lithium compound is oxidized in response to oxygen, The doping of the capacitor can be performed safely and efficiently, thereby improving the performance of the capacitor, high output, and high energy density.

The milling and binder growing step S460 is a step of mixing the conductive agent, the activated carbon and the lithium compound mixed by the powder mixing step S450 and the solid binder by the binder preparing step S440 % By using a powder mixer equipment and controlling the rotation speed of the high-speed rotary knife of the powder mixer equipment to grow (stretch) the binder.

Also, the pulverizing and binder growing step (S460) rotates the high-speed rotary knife of the powder mixer equipment at 3000 to 5000 rpm.

In general, the equipment for mixing and crushing powdery samples includes a ball mill for crushing the different powders through collision with balls, a jet mill for crushing the samples by introducing high pressure air to induce collision between the powders, And an agate bowl in which a sample is crushed to crush the sample.

However, the pulverizing and binder growing step (S460) of the present invention is essentially used for mixing powder (including a conductive agent, an activated carbon, lithium compound) and a binder and for growing (stretching) a binder .

Hereinafter, the reason why the powder mixer apparatus, which is not a conventional grinding apparatus, is applied to the present invention will be described.

In the present invention, a lithium compound is added to a cathode active material to improve the performance of a capacitor. However, in consideration of the physical properties of a lithium compound which reacts with oxygen and water, the preliminary reaction of a lithium compound is blocked. Binder.

The binder may be selected from the group consisting of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyvinyl pyrrolidone, polyvinyl chloride (PVC), polyethylene (PE), styrene butadiene rubber (SBR) Cellulose (CMC), and fluorinated rubber are selected and mixed.

That is, even if the binder is made into a solid phase, the outer surface does not form a high strength and has its own elasticity.

As a result, the binder can not be grown (softened) by a conventional ball mill, a jet mill, and an agate bowl, and the unfavorable growth of the binder (unfrequency) does not impart the deformability and fluidity to the conductive agent, the activated carbon and the lithium compound, The function as a binder for binding is lost.

However, the present invention enables the mixing and growth (softening) of the binder by applying the powder mixer equipment during the grinding and binder growing step (S460). The reason for this is that the powder mixer equipment of the binder can increase the kinetic energy of the binder by the high-speed rotary knife, and the high-speed rotary knife generates the shock acceleration to the binder,

That is, the binder has its own elasticity and grows (stretches) only by using a crushing machine equipped with a high-speed rotary knife such as a powder mixer because it has physical properties to grow (stretch) when thermal energy and kinetic energy above a threshold value are applied .

In this case, since the growth of the binder differs depending on the rotation speed of the high-speed rotary knife, even if the powder mixer equipped with the high-speed rotary knife is used, if the rotation speed of the high-speed rotary knife is not included in the critical range, (Yearly) is not performed or the problem of slow progress occurs.

Accordingly, in the present invention, it is confirmed that the growth of the binder (softening) is optimized when the rotation speed of the high-speed rotary knife is 3000 to 5000 rpm.

FIG. 6 (a) is an exemplary view showing the state of the mixture before the binder of the present invention grows, (b) is an exemplary view showing the state of the mixture when the binder is grown in a predetermined manner, And shows the state of the mixture when grown.

The binder 440 forms a spherical shape as shown in FIG. 6 (a), so that the conductive agent 410, the lithium compound 420, And the activated charcoal 430, as shown in FIG.

In this state, when the powder mixer apparatus is operated and the binder is grown by a high-speed rotary knife in a predetermined growth (soft type), the binder 440 is linearly drawn in a spherical shape as shown in FIG. 6 (b) So that it is possible to bind a part of the conductive agent 410, the lithium compound 420 and the activated carbon 430.

6 (c), when the binder 440 is completely grown (stretched), the conductive agent 410, the lithium compound 420, and the activated carbon 430 are completely linearly drawn, It is possible to impart the deformability and fluidity of the cathode active material 400 by binding the whole.

That is, in the cathode active material dry process, the conductive agent, activated carbon, lithium compound, and binder are mixed with each other by using a mixer equipped with a high-speed rotary knife so that the binder can be efficiently grown (collapsed) do.

Referring again to FIG. 5, the dispersing step S470 is a processing step of dispersing the bound mixture by the milling and binder growing step S460, while uniformly dispersing the particles using the jet mill.

The primary rolling step S480 is a process step of squeezing the mixture by the dispersion step S470 using a hot vertical roll and the secondary rolling step S490 is a step of rolling the mixture squeezed by the primary rolling step S480 And then pressing the sheet using a low-temperature horizontal roll to manufacture the anode sheet 5 described above.

The cutting step S500 is a step of cutting the cathode sheet 5 produced by the second rolling step S490 using a known cutting equipment into a disk shape having a diameter of approximately 12.5 mm and a thickness of 1.0 mm .

Hereinafter, a lithium ion capacitor according to an embodiment of the present invention will be described in more detail with reference to embodiments. The following embodiments are for illustrative purposes only and do not limit the scope of protection of the present invention.

[Example 1]

The positive electrode sheet of Example 1 was produced through the wet process of Figs. 3 and 4 described above.

(Li2NiO2) and activated carbon were mixed at a weight ratio of 4: 1. Then, 85 weight% of the mixture, 10 weight% of a conductive agent (carbon black), 10 weight% of a binder ) Was added to a solvent (IPA, Isopropyl Alcohol), kneaded, pressed by using a roller, and cut to a size of 12.5 mm in diameter and 1.0 mm in thickness to prepare a positive electrode sheet.

After the pulverization and mixing were completed, the mixture was passed through a vertically configured roller to press the mixture, thereby preparing a positive electrode sheet 5. The produced positive electrode sheet 5 had a diameter of 12.5 mm and a thickness of 1.0 mm Cut.

Conductive adhesives 11 and 12 are applied to the bottom wall 21 of the case 2 and the top plate 31 of the cap 3 by using a dispenser and then the negative electrode sheet and the positive electrode sheet And then dried at a high temperature of 250 ° C for 4 hours using an atmospheric circulation oven and dried in a drier having a dew point below -50 ° C. A non-aqueous electrolyte impregnated cap with an electrode impregnated with a non-aqueous electrolyte, an insulating ring packing made of polypropylene (PP), an insulating separator made of nonwoven fabric made of polypropylene (PP) Finally, a cap with an insulative ring packing was inserted into the case, and then the lithium ion capacitor was produced by pressing with a constant force.

At this time, the lithium ion capacitor is manufactured with a diameter of 18.5 mm and a thickness of 2.0 mm.

The thus fabricated lithium ion capacitor is charged at a constant voltage of 4.0 V and a constant current of 1 mA for 12 hours.

[Example 2]

The positive electrode sheet of Example 2 was produced through the dry process of Fig. 5 described above.

(Li2NiO2) and activated carbon were mixed in a weight ratio of 4: 1. Then, 85% by weight of the mixture, 10% by weight of a conductive agent (carbon black), a binder ) Were added and mixed. At this time, a solid phase powder is applied to the binder, and no solvent is used.

The mixture in this state is introduced into a known powder mixer equipment and the mixture is pulverized at a rotation speed of 3000 to 5000 rpm. At this time, the binder of the mixture has an effect of increasing the kinetic energy by the acceleration of the impact by the high-speed rotary knife and not only growing (softening) but also crushing the mixed mixture evenly.

The subsequent manufacturing process was carried out in the same manner as in Example 1.

[Comparative Example 1]

Comparative Example 1 is an electric double layer capacitor (EDLC) manufactured by a wet process.

Comparative Example 1 was prepared by adding 80 wt% of palm-based activated carbon powder, 10 wt% of a conductive agent (carbon black), and 10 wt% of a binder (PTFE; Water and IPA (isopropyl alcohol) were used as solvents.

In addition, the polarized electrode sheet prepared through this process was cut to a size of 12.5 mm in diameter and 0.7 mm in thickness to prepare polarized electrodes.

The subsequent manufacturing process was carried out in the same manner as in Example 1.

[Comparative Example 2]

Comparative Example 2 is an electric double layer capacitor (EDLC) manufactured by a dry process.

In Comparative Example 2, polarizable electrodes were prepared by mixing 80 wt% of palm-based activated carbon powder, 10 wt% of a conductive agent (carbon black), and 10 wt% of a solid phase binder.

The following Table 1 is for comparing the performance of Examples 1 and 2 and Comparative Examples 1 and 2.

Item Example 1
(LIC)
Wet process Example 2
(LIC)
Dry process Comparative Example 1
(EDLC)
Wet process Comparative Example 2
(EDLC)
Dry process Operating Voltage (V) 3.8V 3.8V 2.8V 2.8V Initial capacity (F) 3.9F 4.1F 2.0F 2.1F Self-discharge (V)
(Voltage for 24 hours after charging for 1 hour) 3.71V 3.75V 2.21V 2.35V Capacity reduction rate after 50,000 charge / discharge cycles
(100 average) -14.2% -12.8% -21.6% -19.3% Internal resistance increase rate after 50,000 charge / discharge cycles
(100 average) 235.4% 167.2% 294.3% 213.2% After high temperature load at 70 ℃ for 1,000 hours
Capacity reduction rate (average of 100)
* 3.8V for LIC and 2.8V for EDLC -24.8% -21.1% -27.9% -23.4% After high temperature load at 70 ℃, 2.5V, 1,000 hours
Internal resistance increase rate (100 average)
* 3.8V for LIC and 2.8V for EDLC 345.2% 285.1% -331.4% -301.5%

First, Embodiment 1 is a lithium ion capacitor (LIC) manufactured through a wet process as described above.

Example 2 is a lithium ion capacitor (LIC) manufactured through a dry process.

Comparative Example 1 is an electric double layer capacitor (EDLC) manufactured through a wet process.

Comparative Example 2 is an electric double layer capacitor (EDLC) manufactured through a dry process.

Referring to Table 1, with respect to the operating voltage V, Examples 1 and 2, which are lithium ion capacitors (LIC), have operating voltages V of 3.8 V and 3.8 V, and electric double layer capacitors (EDLC) In Comparative Examples 1 and 2, it can be seen that the operating voltages V are '2.8V' and '2.8V', that is, the comparison between the lithium ion capacitor (LIC) in which the embodiments 1 and 2 are electric double layer capacitors It can be seen that the operating voltage V is higher than in Examples 1 and 2.

The initial capacities F of the first and second embodiments are 3.9F and 4.1F and the operating voltages of the comparative examples 1 and 2 are 2.0F. , And 2.0 F. That is, it can be seen that the initial capacity (F) is superior to that of Comparative Examples 1 and 2 in which the lithium ion capacitor (LIC) Examples 1 and 2 are electric double layer capacitors (EDLC) Since Example 1 is carried out through a wet process, it can be seen that the operating voltage (V) and the initial capacity (F) were measured to be somewhat lower than those of Example 2 by dry process due to the elution and oxidation of lithium ions have.

Also, the self-discharge (V) when the self-discharge (V) was measured by measuring the voltage after leaving for 24 hours after charging the cells of Examples 1 and 2 and Comparative Examples 1 and 2 for 1 hour is shown in Table 1, It can be seen that the self discharge (V) of the discharge cells (1) and (2) is 3.71 V and 3.75 V, and that the self discharge (V) is 2.21 V and 2.35 V, respectively.

That is, it can be seen that the self-discharge (V) is reduced as compared with Comparative Examples 1 and 2 in which Embodiments 1 and 2 which are lithium ion capacitors (LIC) are electric double layer capacitors (EDLC).

In Examples 1 and 2 and Comparative Examples 1 and 2, the capacity reduction rate (%) was -14.2%, the capacity reduction rate (%) was 50% -12.8%, and in Comparative Examples 1 and 2, the capacity decrease rate (%) is -21.6% and -19.3%, respectively.

That is, it can be seen that the capacities of Examples 1 and 2, which are lithium ion capacitors (LIC), are smaller than those of Comparative Examples 1 and 2 which are electric double layer capacitors (EDLC), and Example 2 of the dry process is a wet process It can be seen that the capacity is reduced less than in Example 1.

The internal resistance increase rate (%) in Examples 1 and 2 and Comparative Examples 1 and 2 after 50,000 charge / discharge cycles was 235.4% in Examples 1 and 2, And 167.2%, respectively. In Comparative Examples 1 and 2, the internal resistance increase rate (%) was 294.3% and 213.2%, respectively.

That is, the internal resistance of Example 2, which is a lithium ion capacitor (LIC) in the dry process, is minimized, and the internal resistance of Comparative Example 2, which is an electric double layer capacitor (EDLC) Example 1, which is a lithium ion capacitor (LIC) in a wet process, was measured to have a somewhat higher internal resistance increase rate as compared with Comparative Example 2.

In addition, in Examples 1 and 2 and Comparative Examples 1 and 2, a high temperature load accelerated deterioration test was performed at a temperature of 70 캜 for 1,000 hours under a condition of applying a rated voltage (LIC of 3.8 V and EDLC of 2.8 V) (LIC) of the dry process, the capacitance reduction and the internal resistance were measured to be the smallest, and the electric double layer capacitors of the dry process (%) and the internal resistance increase rate (% (LIC) of the wet process was measured in the same manner as in Comparative Example 2 (Comparative Example 2) in which the capacity reduction rate (%) and the internal resistance increase rate (% (%) And the internal resistance increase rate (%) were measured to be somewhat higher than those of the comparative example.

As described above, the lithium ion capacitor 1 according to the present invention has improved operating voltage, initial capacity and self-discharge as compared with electric double layer capacitors (EDLC) in wet process or dry process manufacture by optimally adjusting the content of the contained components In particular, it can be seen that the performance improves in all functions such as operating voltage, initial capacity, self-discharge, capacity reduction rate, and internal resistance increase rate in the dry process.

Kinds Example 3 Example 4 Example 5 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 anode
Active material Conductive agent 10 wt% 10 wt% 10 wt% 10 wt% 10 wt% 10 wt% 10 wt% 10 wt% bookbinder 10 wt% 10 wt% 10 wt% 10 wt% 10 wt% 10 wt% 10 wt% 10 wt% Lithium compound 8 wt% 8 wt% 8 wt% 8 wt% 8 wt% 8 wt% 8 wt% 8 wt% Activated carbon 72 wt% 72 wt% 72 wt% 72 wt% 72 wt% 72 wt% 72 wt% 72 wt% Crushing equipment powder
mixer powder
mixer powder
mixer powder
mixer powder
mixer Ball mill Ball mill Ball mill Rotation speed 3000rpm 4000rpm 5000rpm 1000rpm 2000rpm 30 rpm 300rpm 3000rpm Grinding time 2 hr 2 hr 2 hr 2 hr 2 hr 2 hr 2 hr 2 hr

[Example 3]

10% by weight of a conductive agent;

10% by weight of a binder;

Li6CoO4 which is a lithium compound of 8% by weight;

72% by weight of activated carbon,

Wherein the primary mixture of the conductive agent, the binder and the lithium compound and the binder are mixed by a powder mixer equipment rotating at a speed of 3000 rpm for 2 hours.

[Example 4]

10% by weight of a conductive agent;

10% by weight of a binder;

Li6CoO4 which is a lithium compound of 8% by weight;

72% by weight of activated carbon,

Wherein the primary mixture of the conductive agent, the binder and the lithium compound and the binder are mixed by a powder mixer equipment rotating at a speed of 4000 rpm for 2 hours.

[Example 5]

10% by weight of a conductive agent;

10% by weight of a binder;

Li6CoO4, which is a lithium compound of 8% by weight;

72% by weight of activated carbon,

A cathode active material mixed with a primary mixture of a conductive agent, a binder and a lithium compound and a binder by means of a powder mixer equipment rotating at a speed of 5000 rpm for 2 hours.

[Comparative Example 3]

10% by weight of a conductive agent;

10% by weight of a binder;

Li6CoO4, which is a lithium compound of 8% by weight;

72% by weight of activated carbon,

Wherein the primary mixture of the conductive agent, the binder and the lithium compound and the binder are mixed by a powder mixer equipment rotating at a speed of 1000 rpm for 2 hours.

[Comparative Example 4]

10% by weight of a conductive agent;

10% by weight of a binder;

Li6CoO4, which is a lithium compound of 8% by weight;

72% by weight of activated carbon,

Wherein the primary mixture of the conductive agent, the binder and the lithium compound and the binder are mixed by a powder mixer equipment rotating at a speed of 2000 rpm for 2 hours.

[Comparative Example 5]

10% by weight of a conductive agent;

10% by weight of a binder;

Li6CoO4, which is a lithium compound of 8% by weight;

72% by weight of activated carbon,

Wherein the binder is mixed with a primary mixture of a conductive agent, a binder and a lithium compound by a ball mill rotating for 2 hours at a speed of 30 rpm.

[Comparative Example 6]

10% by weight of a conductive agent;

10% by weight of a binder;

Li6CoO4, which is a lithium compound of 8% by weight;

72% by weight of activated carbon,

And the binder is mixed by a ball mill rotating at a speed of 300 rpm for 2 hours. The cathode active material is mixed with a primary mixture of a conductive agent, a binder and a lithium compound.

[Comparative Example 7]

10% by weight of a conductive agent;

10% by weight of a binder;

Li6CoO4, which is a lithium compound of 8% by weight;

72% by weight of activated carbon,

A binder, and a primary compound of a lithium compound and a binder are mixed by a ball mill rotating at a speed of 3000 rpm for 2 hours.

[Experimental Example 1]

In Experimental Example 1, the secondary mixture was dispersed and homogenized using a jet mill, and the resultant was pressed with a force of 0.5 N by a vertical roll press at 120 ° C., and visually confirmed whether the sheet was formed.

Table 3 shows the results of Examples 3 to 5 of Table 2 and the results of Experimental Example 1 for Comparative Examples 3 to 7.

Sheet molding Example 3 ○ Example 4 ◎ Example 5 ◎ Comparative Example 3 × Comparative Example 4 △ Comparative Example 5 × Comparative Example 6 × Comparative Example 7 ×

In this case, X is a powder state,? Is a state in which a sheet can not be formed continuously though it is not a powder,? Is a state of being formed into a sheet but having holes or easily cut out, and?

With reference to Table 3, whether or not the sheets of Examples 3 to 5 and Comparative Examples 3 to 7 were formed will be described.

In Example 3, the secondary mixing was performed using a powder mixer equipment rotating at 3000 rpm for 2 hours, so that the binder was actively grown by a high-speed rotary knife rotating at a high speed of 3000 rpm to perform sheet molding, It can be seen that a predetermined hole is formed or cut easily.

In Examples 4 and 5, secondary mixing was performed using powder mixer equipment rotating at 4000 rpm and 5000 rpm for 2 hours, so that binding was actively performed by a high-speed rotary knife, and the sheet was formed accurately.

In Comparative Examples 3 and 4, the powder mixer equipment was applied to the secondary mixing, but the binder was not actively grown (rotation) at 1000 rpm and 2000 rpm at a rotation speed of less than 3000 rpm, so that the powder state was maintained, It can be confirmed that a problem that can not be solved occurs.

In Comparative Examples 5 and 6, since secondary mixing was performed using a ball mill rotating at a low speed of 30 rpm and 300 rpm, no growth of a binder having elasticity (softening) occurred at all, and thus a conductive agent, an activated carbon, It can be seen that the sheet can not be formed.

In Comparative Example 7, secondary mixing was carried out at a high speed of 3000 rpm. However, it was found that the binder was not grown (softened) by applying the milling equipment to the ball mill, and thus the sheet molding failed.

As described above, the lithium ion capacitor 1 according to one embodiment of the present invention is capable of storing and discharging lithium ions in the anode and exhibiting electric double layer performance, thereby increasing the electric energy density and increasing the discharge voltage, Can be effectively used.

The lithium ion capacitor 1 of the present invention is provided with a positive electrode sheet 5, a negative electrode sheet 6, a separator 7 and a non-electrolytic electrolyte 8 in a space between the case 2 and the cap 3 , And the cathode sheet 5 is made to contain the lithium compound in the cathode active material, so that it can be realized without installing a separate lithium metal, so that it can be manufactured in various shapes and forms, and lithium ions can be safely and efficiently doped , The manufacturing process can be simplified.

Also, the lithium ion capacitor 1 of the present invention is configured to produce the positive electrode active material through a wet process in the process of manufacturing the positive electrode active material, thereby remarkably improving the performance of the used voltage and the self-discharge.

In addition, the lithium ion capacitor 1 of the present invention is configured to produce the cathode active material through a dry process in the cathode active material manufacturing process, thereby preventing the lithium compound from being oxidized and eluted by oxygen and water when manufactured by a wet process Thereby improving the performance of high power, high power and high energy density.

Further, the lithium ion capacitor 1 of the present invention performs a primary mixing process for mixing a conductive agent, an activated carbon and a lithium compound in a dry process of the cathode active material in a nitrogen atmosphere, thereby more effectively blocking the pre- It is possible to efficiently prevent the deterioration of performance in advance.

Further, the lithium ion capacitor 1 of the present invention can more precisely block the preliminary reaction of the lithium compound by applying a binder for binding the conductive agent, the activated carbon and the lithium compound in the cathode active material dry process in a solid phase rather than a liquid phase.

In the lithium ion capacitor 1 of the present invention, the conductive agent, the activated carbon, the lithium compound, and the binder are secondarily mixed using a mixer equipped with a high-speed rotary knife during the cathode active material dry process, The present invention provides a lithium ion capacitor and a method of manufacturing the lithium ion capacitor.

1: Lithium ion capacitor 2: Case
3: cap 4: gasket 5: anode sheet
6: negative electrode sheet 7: separator 8: non-electrolytic electrolyte
11: conductive adhesive 12: conductive adhesive 21: bottom
23: vertical wall 31: top plate 33: side wall
S200: Wet process of anode sheet S210, S410: Preparing conductive agent
S220, S420: Activated carbon preparation step S230, S430: Lithium compound preparation step
S240 and S440: binder preparation step S250: primary kneading step
S260: Second Kneading Step S270: Third Kneading Step
Steps S280 and S480: Primary Rolling Step S290, S490: Secondary Rolling Step
S300, S500: Cutting step S450: Powder mixing step
S460: milling and binder growth step S470: dispersion step

Claims (9)

1. A lithium ion capacitor comprising a case which is a positive electrode collector and a case which is formed by a case which is a negative electrode collector and in which a positive electrode sheet, a negative electrode sheet, a separator and an electrolyte are provided,
The positive electrode active material forming the positive electrode sheet
3 to 10% by weight of the conductive agent;
3 to 10% by weight of the binder;
40 to 75 wt% of the activated carbon;
And 5 to 50% by weight of the lithium compound. The method according to claim 1, wherein the cathode active material
3 to 10% by weight of the conductive agent, 40 to 75% by weight of the activated carbon and 5 to 50% by weight of the lithium compound are put into a Kneader and then subjected to primary kneading, Is added to the mixture to complete the secondary kneading, and a binder having a concentration of 40% is added to the resulting mixture to be kneaded, followed by hot pressing. The method of claim 1, wherein the positive electrode active material forming the positive electrode sheet
Wherein the conductive agent, the activated carbon, and the lithium compound are first mixed in a nitrogen purging environment to block the reaction of the lithium compound with oxygen, and a solid binder is added to the primary mixture, Lt; RTI ID = 0.0 > Li-ion < / RTI > capacitor. 4. The process according to claim 3, wherein the grinding equipment applied to the secondary mixing comprises
And a high-speed rotary knife which is a blade rotating into an internal space, wherein the high-speed rotary knife is rotated at a speed of 3000 to 5000 rpm,
Wherein the binder is linearly stretched by the high-speed rotary knife during secondary mixing to bind the conductive agent, the activated carbon, and the lithium compound. The lithium ion capacitor according to claim 2 or 4, wherein the activated carbon is coated with carbon nanotubes (carbon nanotubes) or graphite on its surface. The lithium secondary battery according to claim 1, wherein the lithium compound
Li2MoO3, Li2MnO3, Li2NiO2, Li2PtO3, Li2IrO3, Li2RuO3, Li2SnO3, Li2ZrO3, Li5FeO4, Li6CoO4, and Li5MnO4, or a mixture of at least two or more of them. The method according to claim 1, wherein the negative electrode active material forming the negative electrode sheet
3 to 10 wt% of a conductive material, 3 to 10 wt% of a binder, and 80 to 90 wt% of a soft carbon. The method of claim 1, wherein the binder is selected from the group consisting of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyvinyl pyrrolidone, polyvinyl chloride (PVC), polyethylene (PE), styrene butadiene Wherein at least one of rubber (SBR), carboxymethylcellulose (CMC), and fluorinated rubber is selected and used in combination. The electrolyte according to claim 1, wherein the electrolyte contains a solute capable of intercalating and deintercalating lithium ions, a solute expressing an electric double layer capacity, and a solvent,
The solute which expresses the electric double layer capacity of the electrolyte is tetraethylammonium hexafluorophosphate (C2H5) 44NPF6), tetraethylammonium tetrafluoroborate (C2H5) 44NPF4), tetraethylammonium bis (trifluoro Triethylmethylammoniumbis (trifluoromethanesulfonyl) imide, (C2H5) 44N-N (CF3SO2) 2, Et4NTFSI, TEATFSI), triethylmethylammoniumbis (trifluoromethanesulfonyl) imide, (C 2 H 5) 3 N-N (CF 3 SO 2) 2), triethylmethylammoniumbis (trifluoromethanesulfonyl) imide, (CH 4 (C 2 H 5) 3 N-N (SO 3 CF 2) , And spiro- (1,1 ') -bipyrrolidinium tetrafluoroborate (SPB-BF4) are selected and mixed,
The solute capable of intercalating and deintercalating lithium ions in the electrolyte is preferably selected from the group consisting of lithium perchlorate (LiClO4), lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), 3-fluoromethylsulfonic acid Lithium bis (trifluoromethanesulfonyl) imide, LiN (CF3SO2) 2, LiTFSI), bis (pentafluoroethanesulfonylimide) lithium bis pentafluoroethanesulfonylimide, LiN (SO2C2F5) 2, LiBETI) are selected and mixed,
The solvent is selected from the group consisting of Propylene Carbonate (PC), Ethylene Carbonate (EC), Butylene Carbonate (VC), Vinylene Carbonate (VEC), Dimethyl Carbonate (DMC), Diethyl Carbonate (DEC), Ethylmethyl Carbonate (EMC) N-Dimethyl Formamide (DMF), 1,3-Dimethyl-2-Imidazolidinone (DMI), N, N-Dimethyl Acetamide (DMAC), Sulfolane (SL), γ-Valerolactone At least one selected from the group consisting of dimethylsulfoxide (DMSO), acetonitrile (AN), propionitrile (PN), and tetrahydrofuran (THF) is selected and mixed.

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