KR20020045920A - Method for producing Al-coated activated carbon filament electrode and electrical double layer capacitor using the same - Google Patents

Abstract

PURPOSE: A method for manufacturing electric double layer capacitor with aluminum-coated activated carbon filament electrode is provided to improve an energy density in manufacturing an electric double layer capacitor by manufacturing the electric double layer capacitor with a high-density activated carbon filament electrode. CONSTITUTION: A first process coats aluminum on an activated carbon filament. A second process cuts the aluminum-coated activated carbon filament(4). A third process mixes the aluminum-coated activated carbon filament(4) with a solution in which a binder(6) is solved. A fourth process coats the mixture on an electro condensing body(3) and completes an electrode(1) for electric double layer capacitor. A fifth process locates a high molecular separator(2) between the two electrodes(1) and makes an electric double layer capacitor.

Description

Method for producing Al-coated activated carbon filament electrode and electrical double layer capacitor using the same

The present invention relates to a method of manufacturing an aluminum-coated activated carbon filament electrode and an electric double layer capacitor using the same, and more particularly, to fabricate an electrode having a low resistance and high density using an activated carbon fiber and using the electric double layer The present invention relates to a method of manufacturing a capacitor.

The electric double layer capacitor has a higher power density characteristic than a conventional secondary battery because it stores energy by adsorption of electrolyte ions in the electric double layer existing between the electrode and the electrolyte, and uses a porous activated carbon electrode having a large specific surface area. Better energy density than capacitor

The structure of a general electric double layer capacitor is a structure in which a porous electrode having a porous activated carbon fiber cloth is attached to a current collector in the same manner as a positive / negative electrode, and a polymer membrane is separated between the electrodes, and an electrolyte is filled therein.

In the US Patent No. 5,777,428 (named: Aluminum-carbon composite electrode), aluminum was coated on one side of activated carbon fiber cloth and the aluminum-coated side was attached to the current collector for the purpose of improving the output characteristics of the electric double layer capacitor. . Such a conventional electrode manufacturing method has an effect of improving the output characteristics by reducing the resistance of the activated carbon fiber cloth, but due to the low density of the activated carbon fiber cloth itself has a disadvantage of low density of the electrode and thus low energy density of the electric double layer capacitor.

The present invention has been made to solve the above problems, the object of which is to crush the aluminum-coated activated carbon fiber cloth to a suitable size, and the activated carbon filament coated with the aluminum in a solution (binder) dissolved The present invention is to provide an aluminum-coated activated carbon filament electrode and a method of manufacturing an electric double layer capacitor using the same, by coating a dispersed mixture on an aluminum thin film current collector to improve energy density characteristics by producing a high density electrode.

1 schematically shows a preparation of an aluminum-coated activated carbon filament electrode and an electric double layer capacitor using the same according to the present invention.

※ Explanation of code for main part of drawing

1: polarizing electrode 2: polymer membrane

3: house

4: activated carbon filament coated with aluminum

5: aluminum coated on activated carbon filament

6: binder 7: liquid electrolyte

In order to achieve the above object, a method of manufacturing an aluminum-coated activated carbon filament electrode according to the present invention includes a first step of coating aluminum on an activated carbon fiber cloth; A second step of cutting and pulverizing the activated carbon fiber cloth coated with aluminum of the first step; A third step of mixing the aluminum-coated activated carbon filament in a solution in which a binder is dissolved in a solvent; And a fourth step of uniformly applying the mixture of the third step to the current collector and drying to complete the electrode for the electric double layer capacitor.

In addition, in order to achieve the above object, a method of manufacturing an electric double layer capacitor using an aluminum-coated activated carbon filament electrode according to the present invention, a polymer film (separator) between two sheets of the electrode for the electric double layer capacitor prepared as described above. And placing it in a case, impregnating the electrolyte solution and sealing it to produce an electric double layer capacitor.

As described above, according to the present invention, an aluminum-coated activated carbon filament electrode and a method of manufacturing an electric double layer capacitor using the same are obtained by pulverizing an aluminum-coated activated carbon fiber cloth into an aluminum-coated activated carbon filament. It is characterized by manufacturing.

Hereinafter, an embodiment of an aluminum-coated activated carbon filament electrode and a method of manufacturing an electric double layer capacitor using the same will be described in detail.

EXAMPLE 1

A specific surface area of aluminum as 5㎛ 500~3000m ² / g and preferably 2000m ² / g of ion deposition on one surface of the activated carbon seomyupo (ion vapor deposition) method to a thickness of the coating will be. Aluminum-coated activated carbon fiber cloth is cut with a cutter or chopper and pulverized with a grinder, and an aluminum-coated activated carbon filament (Al-coated activated carbon) having a length ranging from 0.1 μm to 10 μm filament).

0.7 g of carboxymethylcellulose sodium salt (CMC) as a water-soluble binder was dissolved in 30 ml of distilled water, and 10 g of the aluminum-coated activated carbon filament was added and mixed, followed by a doctor blade method. After application and drying at 80 ° C. for 4 hours, an electrode for an electric double layer capacitor was prepared.

A separator was placed between two electrodes prepared as described above, placed in a case, and 1 mol of tetraethylammonium tetrafluoroborate (Et4NBF4) was dissolved in acetonitrile as an organic solvent as an electrolyte salt. Immerse in electrolyte solution. It is sealed with an aluminum can or an aluminum-polymer laminated moisture-proof film to finally prepare an electric double layer capacitor.

At this time, the concentration of the liquid electrolyte can be used in both 0.5 mol to 2.0 mol concentration range. In addition, quaternary ammonium cations (R1R2R3R4N +), lithium cations (Li +), and the like may be used as the cations of the salts used in the electrolyte solution, and the anions are tetrafluoroborate anion (BF4-), perchlorate anion (ClO4-), and hexaflour. Since orophosphate (PF6-) is possible, the salt consisting of a combination of these cations and anions can be used as the electrolyte salt.

In addition, alkyl groups R1, R2, R3, and R4 of the quaternary ammonium cation (R1R2R3R4N +) and quaternary phosphonium cations (R1R2R3R4P +) are H, CH3, CH3CH2, CH3CH2CH2, (CH3) 2CH, CH3CH2CH2CH2, and (CH3), respectively. A cation of a first electrolyte salt which does not contain a ring as a cation which is one of 2CHCH2, CH3CH2 (CH3) CH, and (CH3) 3C, or two alkyl groups are one of CH2CH2, CH2CH2CH2, CH2CH2CH2CH2, CH2CH (CH3) CH2CH2 One of the cations of the second electrolyte salt which forms one or more rings with nitrogen (N) atom and phosphorus (P) atom can be used.

As the organic solvent for dissolving the electrolyte salt, in addition to acetonitrile, ethylene carbonate (Ethylene Carbonate), propylene carbonate (Propylene Carbonate), diethylene carbonate (Diethylene Carbonate), dimethylene carbonate (Dimethylene Carbonate), γ-part Organic solvents such as tyrolactone (γ-butyrolactone), dipropyl carbonate (Dipropyl carbonate), diethoxy ethane or dimethoxy ethane and mixed solvents thereof may be used.

In addition, the deposition method of the aluminum coating may be ion deposition or vacuum deposition, and an activated carbon nonwoven fabric or activated carbon felt may be used in place of the activated carbon fiber fabric, and the weight of the aluminum coated on the activated carbon fiber fabric The ratio should be in the range of 0.1 to 1 weight ratio to the weight of activated carbon fiber cloth.

EXAMPLE 2

A specific surface area of aluminum as 5㎛ 500~3000m ² / g and preferably 2000m ² / g of active plasma spraying on one side of the carbon seomyupo (plasma spray) method and of the coating thickness. Aluminum-coated activated carbon fiber cloth is cut with a cutter or chopper and pulverized with a grinder, and an aluminum-coated activated carbon filament (Al-coated activated carbon) having a length ranging from 0.1 μm to 10 μm filament).

10 g of activated carbon filament coated with aluminum in a solution of 0.7 g of polyvinylidene difluoride as an organic binder in 25 ml of 1-methyl-2-pyrrolidinone as a solvent After the addition and mixing, the aluminum thin film was applied by a doctor blade method and dried at 100 ° C. for 3 hours to prepare an electrode for an electric double layer capacitor.

An electrolyte solution in which a polymer membrane was placed between two electrodes prepared as described above and placed in a case, and then 1 mol of tetraethylammonium tetrafluoroborate (Et4NBF4) was dissolved in acetonitrile as an organic solvent as an electrolyte salt. Impregnated in It is sealed with an aluminum can or an aluminum-polymer laminated moisture-proof film to finally prepare an electric double layer capacitor.

At this time, the concentration of the liquid electrolyte can be used in both 0.5 mol to 2.0 mol concentration range. In addition, quaternary ammonium cations (R1R2R3R4N +), lithium cations (Li +), and the like may be used as the cations of the salts used in the electrolyte solution, and the anions are tetrafluoroborate anion (BF4-), perchlorate anion (ClO4-), and hexaflour. Since orophosphate anions (PF6-) are possible, salts consisting of a combination of these cations and anions can be used as the electrolyte salt.

As the organic solvent for dissolving the electrolyte salt, in addition to the acetonitrile, ethylene carbonate (Ethylene Carbonate), propylene carbonate (Propylene Carbonate), diethylene carbonate (Diethylene Carbonate), dimethylene carbonate (Dimethylene Carbonate), γ-butyrolactone Organic solvents such as (γ-butyrolactone), dipropyl carbonate (DipropylCarbonate), diethoxy ethane, or dimethoxy ethane, and mixed solvents thereof may be used.

In addition, an activated carbon nonwoven fabric or activated carbon felt may be used in place of the activated carbon fiber cloth, and the organic binder may include polyvinylidene fluoride and vinylidene fluoride-hexafluropropylene. Polyvinylidene fluoride-co-hexafluoropropylene, polyacrylonitrile, polyvinyl chloride, polyethylene oxide, polyvinylidene chloride, and polytetrafluoro One polymer of polyethylene (polytetrafluoroethylene) or a mixed polymer thereof may be used, and the weight ratio of aluminum coated on the activated carbon fiber cloth may have a value in the range of 0.1 to 1 weight ratio based on the weight of the activated carbon fiber cloth.

The electric double layer capacitor finally manufactured in the above-described [Example 1] and [Example 2] has a pair of polarizing electrodes 1 laminated with a porous polymer membrane 2 therebetween as shown in FIG. The current collector 3 is structured to be attached to the polarization electrode 1. The polarizing electrode 1 is composed of a binder 6, an activated carbon filament 4 coated with aluminum, an aluminum 5 coated on the activated carbon fiber, and a liquid electrolyte 7.

As described in detail above, according to the present invention, a method of manufacturing an aluminum-coated activated carbon filament electrode and an electric double layer capacitor using the same, wherein the aluminum-coated activated carbon fiber cloth is used as an electrode rather than the method of using an aluminum-coated activated carbon fiber cloth as an electrode By pulverizing the activated carbon fiber cloth to a suitable size, a mixture of aluminum-activated carbon filaments dispersed in a binder solution is coated on an aluminum thin film current collector to produce an electrode, which can be made denser. The effect of improving the energy density in the production of the electric double layer capacitor using this electrode is created.

Claims (14)

First step of coating aluminum on activated carbon fiber cloth: A second step of making the aluminum-coated activated carbon filament by cutting and grinding the activated carbon fiber cloth coated with aluminum of the first step: A third step of mixing the aluminum-coated activated carbon filament in a solution in which a binder is dissolved in a solvent; and The method of manufacturing an aluminum-coated activated carbon filament electrode characterized in that it comprises a fourth step of uniformly applying the mixture of the third step to the current collector and dried to produce an electrode for the electric double layer capacitor. The method of claim 1, Method for producing an aluminum-coated activated carbon filament electrode, characterized in that the use of activated carbon nonwoven fabric or activated carbon felt (felt) in place of the activated carbon fiber fabric. The method of claim 1, The specific surface area of the activated carbon fiber cloth, activated carbon fiber or activated carbon felt has a value in the range of 500 ~ 3000m ² / g method of producing an aluminum-coated activated carbon filament electrode. The method of claim 1, The aluminum coating is a method of producing an aluminum-coated activated carbon filament electrode, characterized in that using the deposition method or spraying method. The method of claim 4, wherein The aluminum is a method of producing an aluminum-coated activated carbon filament electrode characterized in that the coating to have a value in the range of 0.1 to 1 weight ratio to the weight of the activated carbon fiber cloth. The method of claim 1, The method of manufacturing an aluminum-coated activated carbon filament electrode, characterized in that the length of the aluminum-coated activated carbon filament has a value in the range of 0.1 to 10㎛. The method of claim 1, The binder is a method of producing an aluminum-coated activated carbon filament electrode, characterized in that using a water-soluble binder or an organic binder. The method of claim 7, wherein The water-soluble binder is carboxymethyl cellulose sodium salt (carboxymethyl cellulose sodium salt), characterized in that the manufacturing method of the aluminum-coated activated carbon filament electrode. The method of claim 7, wherein The organic binder is polyvinylidene fluoride, polyvinylidene fluoride-co-hexafluoropropylene, polyacrylonitrile, polyvinyl chloride chloride, polyethylene oxide, polyvinylidene chloride, and polytetrafluoroethylene, or a mixed polymer thereof. Method for producing a filament electrode. The method of claim 1, The coating of the fourth step is a method of manufacturing an aluminum-coated activated carbon filament electrode, characterized in that using the doctor blade method. First step of coating aluminum on activated carbon fiber cloth: A second step of making the aluminum-coated activated carbon filament by cutting and grinding the activated carbon fiber cloth coated with aluminum of the first step: The third step of mixing the aluminum-coated activated carbon filament in a solution in which a binder is dissolved in a solvent: A fourth step of uniformly applying and drying the mixture of the third step to a current collector to produce an electrode for an electric double layer capacitor; And A method of manufacturing an electric double layer capacitor, comprising a fifth step of immersing and sealing an electrolyte solution after placing a polymer membrane between two sheets of the prepared electrodes, and placing the polymer membrane in a case. The method of claim 11, The electrolyte solution of the fifth step is to dissolve the electrolyte salt in an organic solvent, The electrolyte salt is tetrafluoroborate anion (BF4-), perchlorate anion (ClO4-), hexaflouro, paired with quaternary ammonium cation (R1R2R3R4N +), quaternary phosphonium cation (R1R2R3R4P +) and lithium cation (Li +). Consisting of a pair of phosphate anions (PF6-) and the like or a mixed salt of these pairs, As the organic solvent, acetonitrile, ethylene carbonate, ethylene carbonate, propylene carbonate, diethylene carbonate, dimethyl carbonate, γ-butyrolactone Butyrolactone, Dipropyl Carbonate, Diethoxy ethane (Diethoxy ethane) or a method for producing an electric double layer capacitor, characterized in that using an organic solvent and a mixed solvent of one of the dimethoxyethane (Dimethoxyethane). The method according to claim 11 or 12, The concentration of the electrolyte is 0.5 ~ 2.0M (mole / liter) method for producing an electric double layer capacitor, characterized in that. The method of claim 12, Alkyl groups R1, R2, R3, and R4 of the quaternary ammonium cation (R1R2R3R4N +) and quaternary phosphonium cations (R1R2R3R4P +) are H, CH3, CH3CH2, CH3CH2CH2, (CH3) 2CH, CH3CH2CH2CH2, (CH3) 2CH2, CH3 Nitrogen characterized in that the cation of the first electrolyte salt containing no ring as a cation which is one of (CH3) CH, (CH3) 3C, or two alkyl groups is one of CH2CH2, CH2CH2CH2, CH2CH2CH2CH2, CH2CH (CH3) CH2CH2 (N) A method for producing an electric double layer capacitor, characterized in that it is one of the cations of the second electrolyte salt which forms one or more rings with atoms and phosphorus (P) atoms.