KR102540653B1 - Manufacturing method of electrode active material for supercapacitor using hydrostatic pressurization and high power supercapacitor using the same and method of manufacturing thereof - Google Patents

Abstract

Disclosed is a method for manufacturing an electrode active material for a high-power supercapacitor using hydrostatic pressurization capable of improving electrical conductivity of the electrode active material by effectively introducing nitrogen into the electrode active material using hydrostatic pressurization, and a high-power supercapacitor using the same and a method for manufacturing the same do.
A method for manufacturing an electrode active material for a high power supercapacitor using hydrostatic pressurization according to the present invention includes the steps of (a) preparing an electrode active material for a supercapacitor; (b) preparing a nitrogen source solution; and (c) doping the electrode active material for the supercapacitor with nitrogen by reacting a nitrogen source solution with the electrode active material for the supercapacitor in a hydrostatic pressure method.

Description

Electrode active material manufacturing method for high-power supercapacitor using hydrostatic pressurization, high-power supercapacitor using the same, and manufacturing method thereof

The present invention relates to a method for manufacturing an electrode active material for a high-power supercapacitor using hydrostatic pressurization, a high-power supercapacitor using the same, and a method for manufacturing the same, and more particularly, to an electrode active material by effectively introducing nitrogen into the electrode active material using hydrostatic pressurization. It relates to a method for manufacturing an electrode active material for a high-power supercapacitor using hydrostatic pressurization capable of improving electrical conductivity, a high-power supercapacitor using the same, and a method for manufacturing the same.

Among next-generation energy storage devices, supercapacitors are attracting attention as next-generation energy storage devices due to their fast charging and discharging speed, high stability, and eco-friendly characteristics. A typical supercapacitor is composed of a porous electrode, a current collector, a separator, and an electrolyte.

A supercapacitor is also called an Electric Double Layer Capacitor (EDLC) or an ultra-capacitor, which is a pair of charge layers with different signs ( electrical double layer) is generated, and the deterioration due to repetition of charging and discharging operations is very small and does not require maintenance.

Accordingly, supercapacitors are mainly used in the form of backing up integrated circuits (ICs) of various electrical and electronic devices. Recently, supercapacitors have been expanded in their use and are widely applied to toys, solar energy storage, HEV (hybrid electric vehicle) power sources, and the like.

Such a supercapacitor generally has two electrodes, an anode and a cathode, impregnated with an electrolyte, and a separator made of a porous material interposed between these two electrodes to enable only ion conduction and to insulate and prevent short circuits, It has a unit cell composed of a gasket for preventing leakage of electrolyte, insulation and short circuit, and a metal cap as a conductor for packaging them. In addition, one or more unit cells configured as above (usually, 2 to 6 in the case of a coin type) are stacked in series, and the two terminals of the positive and negative electrodes are combined to complete.

The performance of supercapacitors is determined by electrode active materials, electrolytes, etc., and in particular, major performance such as capacitance is mostly determined by electrode active materials. Therefore, in recent years, research on the development of high-power supercapacitors capable of exhibiting high-power characteristics by improving the electrical conductivity of electrode active materials has been actively conducted.

As a related prior literature, there is Korean Patent Publication No. 10-2018-0113828 (published on October 17, 2018), which describes a method for producing a positive electrode active material having improved electrochemical properties by grinding and mixing conditions .

An object of the present invention is a method for manufacturing an electrode active material for a high-power supercapacitor using hydrostatic pressurization capable of improving the electrical conductivity of the electrode active material by effectively introducing nitrogen into the electrode active material using hydrostatic pressurization, and a high-power supercapacitor using the same, and the same It is to provide a manufacturing method.

To achieve the above object, a method for manufacturing an electrode active material for a high power supercapacitor using hydrostatic pressurization according to an embodiment of the present invention includes the steps of (a) preparing an electrode active material for a supercapacitor; (b) preparing a nitrogen source solution; and (c) doping the electrode active material for the supercapacitor with nitrogen by reacting a nitrogen source solution with the electrode active material for the supercapacitor in a hydrostatic pressure method.

The electrode active material for the supercapacitor includes at least one selected from graphene, carbon nanotubes, and activated carbons.

The nitrogen source solution may include a nitrogen source; and a solvent for dissolving the nitrogen source.

The nitrogen source and the solvent are preferably added in a volume ratio of 1:5 to 1:15.

The nitrogen source is urea, melamine, polyacrylonitrile, polyaniline, polypyrrole, polyrhodanine, purine, adenine, guanine (Guanine), hypoxanthine (Hypoxanthine), xanthine (Xanthine), theobromine (Theobromine) and caffeine (Caffeine) and includes at least one selected from.

The step (c) includes (c-1) supplying a nitrogen source solution in which 1 to 100 g of the electrode active material and 0.5 to 50 g of a nitrogen source are dissolved in 5 to 500 mL of a solvent to the mold and stirring; and (c-2) injecting the mold after completion of the stirring into a hydrostatic pressurization device to perform hydrostatic pressurization.

In the step (c-2), the hydrostatic pressurization is performed under a pressurization condition of 7,000 kg/cm ² or less at a reaction temperature of 50 to 120 °C.

After step (c), (d) 1 to 100 g of the sample in the mold subjected to hydrostatic pressurization was put into a reactor, and heat treatment was performed at 700 to 1,500 ° C in an inert gas atmosphere to perform nitrogen-doped electrode active material for supercapacitors. forming a; and (e) cooling to room temperature while maintaining the inert gas atmosphere after the heat treatment is finished.

After the step (e), the nitrogen-doped electrode active material for a supercapacitor is doped with 0.5 to 2.0 atomic % of nitrogen based on 100 atomic % of the total.

To achieve the above object, a high-power supercapacitor using hydrostatic pressurization according to an embodiment of the present invention includes a negative electrode including a negative electrode active material, a conductive material, and a binder; a positive electrode disposed spaced apart from the negative electrode and including a positive electrode active material, a conductive material, and a binder; a separator disposed between the negative electrode and the positive electrode to prevent a short circuit between the negative electrode and the positive electrode; and an electrolyte impregnated into the negative electrode and the positive electrode, wherein at least one of the negative electrode active material and the positive electrode active material is a nitrogen-doped supercapacitor electrode active material.

The nitrogen-doped electrode active material for a supercapacitor is doped with 0.5 to 2.0 atomic % of nitrogen based on 100 atomic % of the total.

The high-power supercapacitor exhibits a capacity retention rate of 90% or more under a current density condition of 50 mA/cm ² .

A method for manufacturing a high-power supercapacitor using hydrostatic pressurization according to an embodiment of the present invention for achieving the above object includes the steps of (a) preparing a composition for a supercapacitor electrode by mixing an electrode active material, a conductive material, and a binder in a dispersion medium; (b) pressing the composition for a supercapacitor electrode to form an electrode, coating the composition for a supercapacitor electrode on a metal foil to form an electrode, or pushing the composition for a supercapacitor electrode with a roller to form a sheet Forming an electrode form by attaching it to a metal foil or a current collector; (c) forming a supercapacitor electrode by drying the product formed in the form of the electrode; And (d) using the supercapacitor electrode as an anode and a cathode, disposing a separator between the anode and cathode to prevent a short circuit between the anode and cathode, and impregnating the supercapacitor electrode with an electrolyte solution; ) step, the electrode active material is characterized in that a nitrogen-doped electrode active material for a supercapacitor is used.

In the step (a), the nitrogen-doped electrode active material for a supercapacitor is doped with 0.5 to 2.0 atomic % of nitrogen based on 100 atomic % of the total.

The method for manufacturing an electrode active material for a high-power supercapacitor using hydrostatic pressurization according to the present invention, the high-power supercapacitor using the same, and the method for manufacturing the same, effectively dope the electrode active material with nitrogen using hydrostatic pressurization, thereby increasing the electrical conductivity of the electrode active material. be able to improve

Therefore, when the electrode active material for a supercapacitor manufactured by the method according to the present invention is used in a supercapacitor, it is possible to realize high power characteristics by facilitating charge transfer in an electrolyte solution.

As a result, the high-power supercapacitor using the electrode active material for a supercapacitor manufactured by the method according to the present invention can exhibit a capacity retention rate of 90% or more under the condition of a current density of 50 mA/cm ² .

1 is a process flow chart showing a method for manufacturing an electrode active material for a high-power supercapacitor using hydrostatic pressurization according to an embodiment of the present invention.
2 is a process flow chart showing a method for manufacturing a high-power supercapacitor using hydrostatic pressurization according to an embodiment of the present invention.
3 is a cross-sectional view showing a coin-type supercapacitor according to an embodiment of the present invention.
4 to 7 are schematic diagrams showing a wound-type supercapacitor according to another embodiment of the present invention.
8 is a graph showing the results of XPS analysis of the electrode active material for a supercapacitor prepared according to Comparative Example 1;
9 is a graph showing the results of XPS analysis of the electrode active material for a supercapacitor prepared according to Example 1;
10 is a graph showing the results of evaluating the electrochemical characteristics of the high-power supercapacitors prepared according to Example 1 and Comparative Example 1.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to fully inform the holder of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numbers designate like elements throughout the specification.

Hereinafter, a method for manufacturing an electrode active material for a high-power supercapacitor using hydrostatic pressurization according to a preferred embodiment of the present invention, a high-power supercapacitor using the same, and a method for manufacturing the same will be described in detail with reference to the accompanying drawings.

1 is a process flow chart showing a method for manufacturing an electrode active material for a high-power supercapacitor using hydrostatic pressure according to an embodiment of the present invention.

Referring to FIG. 1, the method for manufacturing an electrode active material for a high-power supercapacitor using hydrostatic pressurization according to an embodiment of the present invention includes a step of preparing an electrode active material for a supercapacitor (S10), a step of preparing a nitrogen source solution (S20), and a step of preparing nitrogen by hydrostatic pressurization. A doping step (S30) and an inert gas atmosphere heat treatment step (S40) are included.

Preparation of electrode active materials for supercapacitors

In the step of preparing an electrode active material for a supercapacitor (S10), an electrode active material for a supercapacitor is prepared.

Here, the electrode active material for the supercapacitor may include at least one selected from graphene, carbon nanotubes, and activated carbons, but is not limited thereto. That is, as an electrode active material for a supercapacitor, in addition to graphene, carbon nanotubes, and activated carbon, any material used for a supercapacitor may be used without limitation.

Prepare nitrogen source solution

In the nitrogen source solution preparation step (S20), a nitrogen source solution is prepared.

Here, the nitrogen source solution includes a nitrogen source and a solvent for dissolving the nitrogen source.

The nitrogen source is a raw material for improving electrical conductivity of the electrode active material for a supercapacitor by doping nitrogen into the electrode active material for a supercapacitor.

For this purpose, nitrogen sources are urea, melamine, polyacrylonitrile, polyaniline, polypyrrole, polyrhodanine, purine, and adenine. , Guanine, hypoxanthine, xanthine, theobromine, and caffeine.

In this step, the nitrogen source and the solvent are preferably added in a volume ratio of 1: 5 to 1: 15, and a more preferable range is 1: 8 to 1: 12 by volume.

Nitrogen doping by hydrostatic pressurization

In the step of doping nitrogen with hydrostatic pressurization (S30), the electrode active material for a supercapacitor is doped with nitrogen by reacting a nitrogen source solution with the electrode active material for a supercapacitor in a hydrostatic pressurization method.

At this time, the nitrogen to be doped into the electrode active material for the supercapacitor is preferably doped at 0.5 to 2.0 atomic% with respect to the total 100 atomic%, and 0.5 to 1.5 atomic% can be suggested as a more preferable range.

If nitrogen is doped at a concentration of less than 0.5 atomic % with respect to 100 atomic % of the total of the electrode active material for a supercapacitor, the concentration is too low and the effect of improving the electrical conductivity of the electrode active material for a supercapacitor may not be exhibited properly. Conversely, if nitrogen is excessively doped by exceeding a concentration of 2.0 atomic% with respect to 100 atomic% of the total electrode active material for supercapacitors, it may act as a factor requiring an excessive amount of nitrogen source without further enhancing the effect. , not economical.

The nitrogen doping step (S30) by hydrostatic pressure is described in more detail as follows.

First, a nitrogen source solution in which 1 to 100 g of an electrode active material and 0.5 to 50 g of a nitrogen source are dissolved in 5 to 500 mL of a solvent is supplied to the mold and stirred. Here, the solvent may be used without limitation as long as it can completely dissolve the nitrogen source, and may be preferably selected from distilled water, ethanol, methanol, and the like.

At this time, stirring is preferably performed for 5 to 10 hours at a speed of 500 to 1,000 rpm. When the stirring speed is less than 50 rpm or the stirring time is less than 5 hours, uniform mixing between the electrode active material for a supercapacitor and the nitrogen source solution may not be achieved. Conversely, when the stirring speed exceeds 1,000 rpm or the stirring time exceeds 10 hours, it is not economical because it acts as a factor that only increases process cost and time without further increasing the effect.

Next, the agitated mold is put into a hydrostatic pressurization device to perform hydrostatic pressurization.

The hydrostatic pressurization device is a device that uses the principle that pressure is transmitted uniformly in all directions. Such a hydrostatic pressurizing device uses a liquid such as water or oil so that the same pressure can be applied. At this time, the hydrostatic pressurization device enables the same force to be transmitted in the same direction to an object injected into a fluid such as water or oil, that is, a mold filled with an electrode active material for a supercapacitor and a nitrogen source solution. To this end, the hydrostatic pressure treatment device puts the electrode active material for supercapacitor and nitrogen source solution, which are the materials to be treated, into a mold and applies high pressure to the electrode active material for supercapacitor and nitrogen due to the pressure generated by the fluid filled inside. A uniform force acts on all surfaces of the source solution, so that a heterogeneous element, that is, nitrogen, can be doped in a short time.

Such hydrostatic pressurization is preferably carried out under conditions of pressurization of 7,000 kg/cm ² or less, more specifically, 3,000 to 6,000 kg/cm ² at a reaction temperature of 50 to 120°C. When hydrostatic pressurization is performed under pressurization conditions of 7,000 kg/cm ² or less at a reaction temperature of 50 to 120° C., nitrogen doping can be completed within 60 minutes, more specifically within a short time of 10 to 60 minutes. .

When the hydrostatic pressurization exceeds 7,000 kg/cm ² , the mold may be damaged due to excessive pressure, so the upper limit of the hydrostatic pressurization is preferably set to 7,000 kg/cm ² .

In addition, when the reaction temperature at the time of hydrostatic pressurization is less than 50° C., nitrogen doping cannot be performed smoothly even when a high pressure is applied, which may act as a factor in increasing the nitrogen doping time. Conversely, when the reaction temperature during hydrostatic pressurization exceeds 120° C., it is not economical because it may act as a factor that only increases manufacturing cost and time without further effect.

Heat treatment in an inert gas atmosphere

In the inert gas atmosphere heat treatment step (S40), 1 to 100 g of the sample in the mold subjected to hydrostatic pressurization is put into a reactor, and heat treatment is performed under the condition of 700 to 1,500 ° C in an inert gas atmosphere to form a nitrogen-doped electrode active material for a supercapacitor. do. Here, heat treatment in an inert gas atmosphere is performed to remove impurities after performing nitrogen doping by hydrostatic pressurization. As the inert gas used to create such an inert gas atmosphere, at least one selected from Ar, N ₂ , and the like may be used, but is not limited thereto.

In addition, after the heat treatment in an inert gas atmosphere is completed, a process of cooling to room temperature while maintaining an inert gas atmosphere may be further included.

The above-described method for manufacturing an electrode active material for a high power supercapacitor using hydrostatic pressurization according to an embodiment of the present invention can improve the electrical conductivity of the electrode active material by effectively doping nitrogen into the electrode active material using hydrostatic pressurization.

Therefore, when the electrode active material for a supercapacitor manufactured by the method according to the embodiment of the present invention is used in a supercapacitor, it is possible to realize high power characteristics by facilitating charge transfer in the electrolyte solution.

As a result, the high-power supercapacitor using the electrode active material for supercapacitor manufactured by the method according to the embodiment of the present invention can exhibit a capacity retention rate of 90% or more under the condition of a current density of 50 mA/cm ² .

Hereinafter, a high power supercapacitor using hydrostatic pressurization according to an embodiment of the present invention and a manufacturing method thereof will be described with reference to the accompanying drawings.

2 is a process flow chart showing a method for manufacturing a high-power supercapacitor using hydrostatic pressurization according to an embodiment of the present invention.

As shown in FIG. 2, the method for manufacturing a high-power supercapacitor using hydrostatic pressurization according to an embodiment of the present invention includes forming a composition for a supercapacitor electrode (S110), forming an electrode shape (S120), and forming a supercapacitor electrode. (S130) and electrolyte impregnation step (S140).

Formation of composition for supercapacitor electrode

In the step of forming a composition for a supercapacitor electrode (S110), a composition for a supercapacitor electrode is prepared by mixing an electrode active material, a conductive material, and a binder in a dispersion medium.

The composition for a supercapacitor electrode includes an electrode active material, 1 to 20 parts by weight of a conductive material based on 100 parts by weight of the electrode active material, 1 to 20 parts by weight of a binder based on 100 parts by weight of the electrode active material, and 100 to 300 parts by weight of a dispersion medium based on 100 parts by weight of the electrode active material. It is desirable to include wealth.

Such a composition for a supercapacitor electrode may be difficult to uniformly mix (completely disperse) because it is in the form of dough, and it may be difficult to mix it uniformly (completely disperse) for a predetermined time (eg, 10 minutes to 12 hours) using a mixer such as a planetary mixer. While stirring, a composition for a supercapacitor electrode suitable for manufacturing an electrode can be obtained. A mixer such as a planetary mixer enables the preparation of a uniformly mixed composition for a supercapacitor electrode.

As the electrode active material, one manufactured by the method for manufacturing an electrode active material for a high power supercapacitor using hydrostatic pressure according to an embodiment of the present invention described with reference to FIG. 1 is used. As described above, the electrode active material of the present invention is uniformly doped with nitrogen on the entire surface of the electrode active material using hydrostatic pressurization, thereby improving the electrical conductivity of the electrode active material and facilitating charge transfer in the electrolyte solution, resulting in high output characteristics can be exhibited.

Binders include polytetrafluoroethylene (PTFE), polyvinylidenefloride (PVdF), carboxymethylcellulose (CMC), polyvinyl alcohol (PVA), and polyvinyl butyral (PVB). ; poly vinyl butyral), polyvinylpyrrolidone (PVP; poly-N-vinylpyrrolidone), styrene butadiene rubber (SBR; styrene butadiene rubber), polyamide-imide, polyimide, etc. One selected type or a mixture of two or more types may be used.

The conductive material is not particularly limited as long as it is an electron conductive material that does not cause chemical change, and examples thereof include natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, Super-P black, carbon fiber, copper, nickel, Metal powder or metal fiber, such as aluminum and silver, is possible.

As the dispersion medium, an organic solvent such as ethanol (EtOH), acetone, isopropyl alcohol, N-methylpyrrolidone (NMP), or propylene glycol (PG) or water may be used.

formed in the form of an electrode

In the step of forming an electrode (S120), the composition for a supercapacitor electrode is compressed to form an electrode, the composition for a supercapacitor electrode is coated on a metal foil to form an electrode, or the composition for a supercapacitor electrode is pushed with a roller to form a sheet. It is made into a state and attached to a metal foil or a current collector to form an electrode form.

To describe an example of the step of forming the electrode shape in more detail, the composition for a supercapacitor electrode may be compressed and molded using a roll press molding machine. The purpose of the roll press molding machine is to improve electrode density and control the thickness of electrodes through rolling. consists of parts As the rolled electrode passes through the roll press, the rolling process proceeds, and this is wound into a roll again to complete the electrode. At this time, the pressing pressure of the press is preferably 5 to 20 ton/cm 2 and the temperature of the roll is 0 to 150° C.

In addition, looking at another example in the form of an electrode, the composition for a supercapacitor electrode is coated on a metal foil such as titanium foil, aluminum foil, or aluminum etching foil. Alternatively, the composition for a supercapacitor electrode may be pushed with a roller to form a sheet (rubber type) and attached to a metal foil or a metal current collector to form an electrode shape. Here, the aluminum etching foil means that the aluminum foil is etched in a concavo-convex shape.

Formation of supercapacitor electrodes

In the supercapacitor electrode forming step (S130), a supercapacitor electrode is formed by drying the product formed in the form of an electrode.

The composition for a supercapacitor electrode that has undergone the press pressing process is subjected to a drying process. The drying process is performed at a temperature of 100 ° C to 350 ° C, preferably 150 ° C to 300 ° C. At this time, when the drying temperature is less than 100 ° C., it is difficult to evaporate the dispersion medium, which is not preferable, and when drying at a high temperature exceeding 350 ° C., oxidation of the conductive material may occur. Therefore, the drying temperature is preferably at least 100°C or higher and does not exceed 350°C. And, it is preferable to proceed with the drying process for 10 minutes to 6 hours at the same temperature as above. In this drying process, the molded supercapacitor electrode composition is dried (dispersion medium evaporation) and at the same time the powder particles are bound to improve the strength of the supercapacitor electrode.

On the other hand, when the electrode is formed by another example formed in the form of an electrode, it is preferable to dry at a temperature condition of 100 to 250 ° C, preferably 150 to 200 ° C.

electrolyte impregnation

In the electrolyte impregnation step (S140), supercapacitor electrodes are used as anodes and cathodes, a separator is placed between the anodes and cathodes to prevent a short circuit between the anodes and cathodes, and the anodes and cathodes are impregnated with the electrolyte of the supercapacitor.

Here, the electrolyte of the supercapacitor may include a non-aqueous electrolyte and an ionic liquid added in an amount of 1 to 25 parts by weight based on 100 parts by weight of the non-aqueous electrolyte.

The coin-type supercapacitor manufactured by the above processes (S110 to S140) is uniformly doped with nitrogen on the entire surface of the electrode active material using hydrostatic pressure, so that the electrical conductivity of the electrode active material can be greatly improved. It is possible to exhibit high output characteristics by facilitating charge transfer of the electrolyte.

This will be described in more detail with reference to the accompanying drawings below.

3 is a cross-sectional view showing a coin-type supercapacitor according to an embodiment of the present invention.

In FIG. 3, reference numeral 190 denotes a metal cap as a conductor, reference numeral 160 denotes a separator made of a porous material for insulating and preventing a short circuit between the anode 120 and the cathode 110, and reference numeral 192 denotes electrolyte leakage. It is a gasket for insulation and short circuit prevention. At this time, the positive electrode 120 and the negative electrode 110 are firmly fixed by the metal cap 190 and the adhesive.

The coin-type supercapacitor has a positive electrode 120 and a negative electrode 110, and a separator 160 disposed between the positive electrode 120 and the negative electrode 110 to prevent a short circuit between the positive electrode 120 and the negative electrode 120. ) can be placed in the metal cap 190, an electrolyte solution is injected between the anode 120 and the cathode 110, and then sealed with a gasket 192.

The separator 160 is not particularly limited as long as it is a separator generally used in the battery field, such as polyolefin, polyethylene, or polypropylene.

Meanwhile, FIGS. 4 to 7 are schematic diagrams showing a wound-type supercapacitor according to another embodiment of the present invention, and a method of manufacturing the wound-type supercapacitor according to another embodiment of the present invention will be described in detail with reference to these diagrams.

Methods for preparing the anode and cathode compositions for supercapacitors are the same as those described above.

Anode and cathode compositions for supercapacitors are coated on metal foil such as Cu foil, Al foil, and aluminum etching foil, or the composition for supercapacitor electrodes is applied with a roller. It is made into a sheet state (rubber type) by pushing and attached to a metal foil or a current collector to form an anode and a cathode. A drying process is performed for the anode and cathode shapes that have undergone this process. The drying process is performed at a temperature of 100 to 350°C, preferably 150 to 300°C. At this time, when the drying temperature is less than 100 ° C., it is difficult to evaporate the dispersion medium, which is not preferable, and when drying at a high temperature exceeding 350 ° C., oxidation of the conductive material may occur. Therefore, the drying temperature is preferably at least 100°C or higher and does not exceed 350°C.

And, it is preferable to proceed with the drying process for 10 minutes to 6 hours at the same temperature as above. In this drying process, the composition for the supercapacitor electrode is dried (evaporation of the dispersion medium) and at the same time, the strength of the supercapacitor electrode is improved by binding the powder particles.

As shown in FIG. 4, lead wires 130 and 140 are attached to the positive electrode 120 and the negative electrode 110 prepared by coating the negative electrode and the positive electrode composition for a supercapacitor on metal foil or forming a sheet and attaching it to the metal foil or current collector. ) is attached.

Next, as shown in FIG. 5, the first separator 150, the positive electrode 120, the second separator 160, and the negative electrode 110 are laminated and coiled to form a roll. After manufacturing the winding element 175, it is wound around the roll with an adhesive tape 170 or the like so that the roll shape can be maintained.

The second separator 160 provided between the positive electrode 120 and the negative electrode 110 serves to prevent a short circuit between the positive electrode 120 and the negative electrode 110 . Each of the first and second separators 150 and 160 is not particularly limited as long as it is a separator generally used in the battery field, such as polyolefin, polyethylene, or polypropylene.

Next, as shown in FIG. 6 , a sealing rubber 180 is mounted on the roll-shaped product and inserted into a metal cap (eg, an aluminum case) 190 .

The winding element 175 in the form of a roll is impregnated, injected with electrolyte, and sealed.

As such, the fabricated supercapacitor is schematically shown in FIG. 7 .

In the supercapacitor 100 manufactured as described above, the positive electrode 120 and the negative electrode 110 are spaced apart from each other, and the positive electrode 120 and the negative electrode 110 are disposed between the positive electrode 120 and the negative electrode 110. Separators 150 and 160 are disposed to prevent a short circuit, and the anode 120 and the cathode 110 are impregnated with electrolyte.

Here, the electrolyte includes a non-aqueous electrolyte and 1 to 25 parts by weight of an ionic liquid based on 100 parts by weight of the non-aqueous electrolyte, and the non-aqueous electrolyte includes an organic solvent, lithium salt LiPF ₆ (lithium hexafluorophosphate), LiBF ₄ (lithium tetrafluoroborate), LiClO ₄ (lithium perchlorate), LiFSI (lithium bis(fluorosulfonyl)imide), sodium salt NaPF ₆ (sodium hexafluorophosphate), NaDFOB (sodium difluoro(oxalate)borate), potassium salt KFSI (potassium bis(fluorosulfonyl) imide), and at least one electrolyte salt selected from the group consisting of KPF ₆ (potassium hexafluorophosphate). The organic solvent is acetonitrile, propylene carbonate, ethylene carbonate, ethylmethyl carbonate, dimethyl carbonate, diethyl carbonate, butylene carbonate, vinylene carbonate, tetrahydrofuran, 1,2-dioxane, 2 - It may contain one or more substances selected from the group consisting of methyltetrahydrofuran, butyrolactone and dimethylformamide.

Ionic liquids include BMITf ₂ N (1-Butyl-3-methylimidazolium trifluoromethanesulfonylamide), EMITFSI (1-Ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide), BMIMBF ₄ (1-Butyl-3-methylimidazolium tetrafluoroborate), OMIMBF ₄ ( 1-Methyl-3-octylimidazolium tetrafluoroborate), OMIMTf ₂ N (1-Methyl-3-octylimidazolium trifluoromethanesulfonylamide), MEMPBF ₄ (N-(2-Methoxyethyl)-N-methylpyrrolidinium tetrafluoroborate) and DEMEBF ₄ (N,N-Diethyl- N-methyl-N- (2-methoxyethyl) ammonium tetraflioroborate) may include one or more materials selected from the group consisting of.

Example

Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, this is presented as a preferred example of the present invention and cannot be construed as limiting the present invention by this in any sense.

Contents not described herein can be technically inferred by those skilled in the art, so descriptions thereof will be omitted.

1. Sample Preparation

Example 1

Manufacture of electrode active materials for supercapacitors

In order to introduce nitrogen into CEP21KS, a commercially available activated carbon, a nitrogen source solution, which is a mixed solution of 10 g of CEP21KS, 5 g of urea, and 50 mL of ethanol, was added to an elastomer mold, and stirred at 700 rpm for 6 hours.

Next, after the stirring was completed, the elastomer mold was put into a hydrostatic pressurization device, and then pressurized for 30 minutes from a reaction temperature of 120° C. to 5,000 kg/cm ² . The sample subjected to hydrostatic pressurization was placed in an alumina reactor and heat-treated at 900° C. using a heat-treater in N ₂ atmosphere.

Next, after the heat treatment was completed, the sample was cooled to room temperature (15° C.) in an N ₂ atmosphere to prepare a nitrogen-doped electrode active material sample for a supercapacitor.

Manufacture of high-power supercapacitors

Put 0.9g of nitrogen-doped electrode active material for supercapacitor, 0.05g of carbon black (super-p) as a conductive material, and 0.05g of PTFE (Polytetrafluoroethylene) as a binder into ethanol as a dispersion medium, and mix with a planetary mixer for 3 minutes. After mixing to prepare a slurry, hand kneading was performed 8 times to prepare an electrode composition for a supercapacitor.

Next, the electrode composition for supercapacitor is rolled with a roll press at a pressurized pressure of 10 ton/cm 2 and a roll temperature of 60° C. to form a sheet and attached to the current collector, then placed in a vacuum dryer at 150° C. and dried for 12 hours. to prepare electrodes for supercapacitors with a thickness of 150 μm.

Next, the vacuum-dried supercapacitor electrode was used as a cathode and an anode, respectively, assembled into a 2032 coin cell, and then impregnated with an electrolyte to prepare a supercapacitor. At this time, the separator used was TF4035, and the electrolyte was 1 M TEABF ₄ /ACN, an electrolyte for supercapacitors.

Comparative Example 1

A supercapacitor was manufactured in the same manner as in Example 1, except that CEP21KS, a commercially available activated carbon, was used as an electrode active material for the supercapacitor, without nitrogen doping the commercially available activated carbon, CEP21KS.

2. XPS analysis

Table 1 shows the results of XPS analysis of the electrode active materials for supercapacitors prepared according to Example 1 and Comparative Example 1. 8 is a graph showing the results of XPS analysis of the electrode active material for a supercapacitor prepared according to Comparative Example 1, and FIG. 9 is a graph showing the result of XPS analysis of the electrode active material for a supercapacitor prepared according to Example 1.

[Table 1]

As shown in Table 1 and FIG. 8, as can be seen from the results of the XPS analysis, nitrogen was not detected in the electrode active material for a supercapacitor prepared according to Comparative Example 1.

On the other hand, as shown in Table 1 and FIG. 9, as can be seen from the results of the XPS analysis, it can be confirmed that the electrode active material for a supercapacitor prepared according to Example 1 is doped with nitrogen by hydrostatic pressurization, and nitrogen is detected. can

3. Electrochemical performance evaluation

Table 2 shows the electrical conductivity measurement results of the supercapacitors prepared according to Example 1 and Comparative Example 1. 10 is a graph showing the results of measuring the specific capacitance values for each current density of the supercapacitors manufactured according to Example 1 and Comparative Example 1.

At this time, the constant current charging and discharging method was used to measure the capacitance of the supercapacitors prepared according to Example 1 and Comparative Example 1, ratio characteristics according to various current densities, leakage current, and voltage drop (IR-drop) during discharge. (Galvanostatic Charge/Discharge test) was performed. The equipment used for the measurement was a Potentiostat (VSP, EC-Lab, France), and the voltage range of 0 ~ 2.7V at room temperature was 0.5, 1, 2, 5, 10, 20, 30, 50 mA/cm ² of The electrochemical performance was measured at various current densities.

[Table 2]

As shown in Table 2, as a result of measuring the electrical conductivity and comparing the electrical conductivity of the supercapacitors manufactured according to Example 1 and Comparative Example 1, the electrical conductivity of Example 1 was generally improved compared to Comparative Example 1. can confirm what has happened.

In addition, as shown in FIG. 10, as can be seen from the results of measuring the electrochemical performance at various current densities of 0.5, 1, 2, 5, 10, 20, 30, and 50 mA/cm ² , Example 1 It can be seen that the specific capacitance value for each current density was measured higher than that of the supercapacitor manufactured according to Comparative Example 1.

As can be seen from the above experimental results, in the case of Example 1 in which nitrogen was uniformly doped on the entire surface of the electrode active material using hydrostatic pressurization, the electrical conductivity of the electrode active material was improved to facilitate charge transfer of the electrolyte, resulting in high output characteristics demonstrated that it works.

Although the above has been described based on the embodiments of the present invention, various changes or modifications may be made at the level of a technician having ordinary knowledge in the technical field to which the present invention belongs. Such changes and modifications can be said to belong to the present invention as long as they do not deviate from the scope of the technical idea provided by the present invention. Therefore, the scope of the present invention will be determined by the claims described below.

S10: Electrode active material preparation step for supercapacitor
S20: Nitrogen source solution preparation step
S30: Nitrogen doping step by hydrostatic pressurization
S40: Inert gas atmosphere heat treatment step

Claims (14)

(a) preparing an electrode active material for a supercapacitor;
(b) preparing a nitrogen source solution; and
(c) doping the electrode active material for the supercapacitor with nitrogen by reacting a nitrogen source solution with the electrode active material for the supercapacitor in a hydrostatic pressurization method;
The step (c) includes (c-1) supplying a nitrogen source solution in which 1 to 100 g of the electrode active material and 0.5 to 50 g of a nitrogen source are dissolved in 5 to 500 mL of a solvent to the mold and stirring; and (c-2) injecting the agitated mold into a hydrostatic pressurization device to perform hydrostatic pressurization;
In the step (c-2), the hydrostatic pressurization is performed for 10 to 60 minutes under a pressurization condition of 3,000 to 6,000kg/cm ² at a reaction temperature of 50 to 120 °C. Electrode active material manufacturing method.
According to claim 1,
The electrode active material for the supercapacitor is
A method for manufacturing an electrode active material for a high-power supercapacitor using hydrostatic pressure, characterized in that it comprises at least one selected from among graphene, carbon nanotubes, and activated carbons.
According to claim 1,
The nitrogen source solution is
nitrogen source; and
a solvent for dissolving the nitrogen source;
Method for producing an electrode active material for a high-power supercapacitor using hydrostatic pressure, characterized in that it comprises a.
According to claim 1,
The nitrogen source and solvent are
A method for manufacturing an electrode active material for a high-power supercapacitor using hydrostatic pressure, characterized in that it is added in a volume ratio of 1: 5 to 1: 15.
According to claim 1,
The nitrogen source is
Urea, Melamine, Polyacrylonitrile, Polyaniline, Polypyrrole, Polyrhodanine, Purine, Adenine, Guanine, A method for manufacturing an electrode active material for a high-power supercapacitor using hydrostatic pressure, characterized in that it contains at least one selected from hypoxanthine, xanthine, theobromine and caffeine.
delete delete According to claim 1,
After step (c),
(d) injecting 1 to 100 g of the sample in the mold in which the hydrostatic pressure has been completed into a reactor and heat-treating the sample in an inert gas atmosphere at 700 to 1,500 ° C to form a nitrogen-doped electrode active material for a supercapacitor; and
(e) cooling to room temperature while maintaining the inert gas atmosphere after the heat treatment is finished;
Method for producing an electrode active material for a high-power supercapacitor using hydrostatic pressurization, characterized in that it further comprises.
According to claim 8,
After step (e),
The electrode active material for a supercapacitor doped with nitrogen is
A method for producing an electrode active material for a high-power supercapacitor using hydrostatic pressurization, characterized in that the nitrogen is doped at 0.5 to 2.0 atomic% with respect to the total 100 atomic%.
A negative electrode including a negative electrode active material, a conductive material and a binder;
a positive electrode disposed spaced apart from the negative electrode and including a positive electrode active material, a conductive material, and a binder;
a separator disposed between the negative electrode and the positive electrode to prevent a short circuit between the negative electrode and the positive electrode; and
Including; electrolyte impregnated in the cathode and anode,
At least one of the negative electrode active material and the positive electrode active material is an electrode active material for a supercapacitor doped with nitrogen prepared by any one of claims 1 to 5 and 8 to 9,
The nitrogen-doped electrode active material for a supercapacitor is nitrogen-doped using hydrostatic pressurization performed at a reaction temperature of 50 to 120 ° C. and a pressurization condition of 3,000 to 6,000 kg / cm ² for 10 to 60 minutes,
The nitrogen-doped electrode active material for a supercapacitor is doped with 0.5 to 2.0 atomic % of nitrogen with respect to a total of 100 atomic %.
delete According to claim 10,
The high-power supercapacitor
A high-power supercapacitor using hydrostatic pressurization, characterized in that it exhibits a capacity retention rate of 90% or more under a current density condition of 50 mA / cm ² .
(a) preparing a composition for a supercapacitor electrode by mixing an electrode active material, a conductive material, and a binder in a dispersion medium;
(b) pressing the composition for a supercapacitor electrode to form an electrode, coating the composition for a supercapacitor electrode on a metal foil to form an electrode, or pushing the composition for a supercapacitor electrode with a roller to form a sheet Forming an electrode form by attaching it to a metal foil or a current collector;
(c) forming a supercapacitor electrode by drying the product formed in the form of the electrode; and
(d) using the supercapacitor electrode as an anode and a cathode, disposing a separator between the anode and cathode to prevent a short circuit between the anode and cathode, and impregnating the anode with an electrolyte,
In the step (a), the electrode active material for a supercapacitor doped with nitrogen prepared by any one of claims 1 to 5 and 8 to 9 is used,
The nitrogen-doped electrode active material for a supercapacitor is nitrogen-doped using hydrostatic pressurization performed for 10 to 60 minutes at a reaction temperature of 50 to 120° C. under a pressurization condition of 3,000 to 6,000 kg/cm ² ,
The nitrogen-doped electrode active material for a supercapacitor is doped with nitrogen in an amount of 0.5 to 2.0 atomic% with respect to a total of 100 atomic%. delete

Images