KR20120116256A - Sheet electrode of carbon-polytetrafluoroethylene-hydrophilic binder for electric double layer capacitor and manufacturing method thereof - Google Patents

Abstract

PURPOSE: A carbon-polytetrafluoroethylene(PTFE)-hydrophilic binder sheet electrode for an electric double layer capacitor and a manufacturing method thereof are provided to easily control the thickness of the carbon-PTFE sheet electrode by using PTFE. CONSTITUTION: Hydrophilic binder solution is formed by dissolving hydrophilic binder in solvent. A paste composition is formed by kneading the mixture of activated carbon, PTFE and the hydrophilic binder solution. A sheet is formed by rolling the paste composition. The sheet is attached on a metal foil by using a conductive adhesive.

Description

Sheet Electrode Of Carbon-PolyTetraFluoroEthylene-Hydrophilic Binder For Electric Double Layer Capacitor And Manufacturing Method

The present invention relates to an electrode of an electric double layer capacitor and a method of manufacturing the same, and more particularly, to develop a sheet electrode manufacturing method excellent in controlling the thickness of the carbon-PTFE sheet electrode and excellent electrolyte solution impregnation while using PTFE as a binder. The present invention relates to a carbon-polytetrafluoroethylene-hydrophilic binder sheet electrode for an electric double layer capacitor having excellent electrical and mechanical properties, and a method of manufacturing the same.

In general, an electric double layer capacitor is configured such that a pair of polarizable electrodes or a double layer electrode of an electrolyte is disposed with a separator having excellent insulation therebetween. Unlike general batteries, energy can be input and output in a short time, which is applied to rectifier circuits, noise reduction, and power generation pulses. Recently, the electric double layer capacitor has been developed, which has greatly increased capacity compared to the existing electrochemical capacitors used in electronic devices. The application of output pulse power and peak power for load leveling is being promoted. In addition, the use of electric double layer capacitors, which are important in terms of environment and economics due to the use of environmentally friendly materials, long life and high charging and discharging efficiency, are used for military, aerospace, medical, It is expected to be used as the main power source and auxiliary power source of high output pulse power of high value added equipment such as electric vehicle (HEV).

The electrode of such an electric double layer capacitor is generally composed of activated carbon, a conductive material and a bonding material excellent in electrical conductivity, and these components are combined in a constant ratio in consideration of capacitance and electrode resistance and then adhered to the current collector. In general, a method of preparing an electrode is a slurry coating method in which a binder is dissolved in a predetermined ratio of activated carbon powder or fiber in a solvent, and a conductive material such as carbon black is mixed to make a slurry and coated on a metal foil. And sheet lamination, in which the activated carbon and the conductive material are prepared together with PTFE (PolyTetraFluoroEthylene) binder in the form of a sheet in a paste state and then bonded to a metal foil or adhered to the metal foil through a conductive adhesive. Can be divided in a way.

In the case of slurry coating method, commercialization is proceeding first in terms of price. In this case, in order to secure the electrical conductivity, flexibility, and impregnation of the electrolyte, it is common to use at least two or more types of mixed binders for the active material and the conductive material. As a binder, at least two types, and a mixture of less than five types of mixed binders are used. For this purpose, the selection of the binder, the mixing method, the mixing order, and the content ratio are important variables.

In contrast, the sheet laminating method simply selects a binder because the electrode is manufactured by rolling a paste obtained by kneading activated carbon and a conductive material together with PTFE.

However, sheet laminating has many difficulties in application to commercialization, although the number of components of the electrode is low and the electrode has excellent chemical, thermal stability and mechanical strength.

In order to reduce the electrode resistance, the electrode should be dried after coating the sheet with a conductive adhesive in a liquid phase to reduce the electrode resistance, adhering the sheet through the roll press, and increasing the adhesion through the roll press. In order to reduce the specifications of the electrode (torsional distortion of the electrode), a precise attachment method should be developed.

On the other hand, the thickness of the sheet is controlled by rolling, and as the number of rolling repetitions is increased, and the gap between rolls is narrow, the thickness decreases and the electrode density increases. In the initial rolling, the fiber resin of PTFE increases to form a network structure, but when the thickness is less than 100 μm, the network structure of the fiber is dense so that no further decrease in electrode thickness occurs. By increasing the contact resistance of the electrode or the internal resistance of the electric double layer capacitor to increase the electrical output characteristics of the electric double layer capacitor and there is a problem of reducing the charge and discharge cycle life.

In order to use the carbon-PTFE sheet as a winding type inside the cell, the thickness of the electrode is preferably 100 μm or less. If the thickness of the electrode is 100 μm or more, a free space at the center of the winding is required. Deterioration of the electrochemical properties occurs as the charge and discharge cycle of the cell increases.

In addition, the carbon-PTFE sheet decreases the electrolyte impregnation property of the electrode as the hydrophobic (Hyrdophobic) PTFE content increases. As the carbon-PTFE electrode thickness decreases, and as the electrode density increases, the fibrous network of PTFE becomes denser, so that the impregnation of the electrolyte decreases.

When the impregnation of the electrolyte is reduced, it is difficult to access the electrolyte to the internal pores of the activated carbon, and thus the cost of forcing the impregnation of the electrolyte into the activated carbon through a high voltage and a long charge in the formation step after manufacturing the cell. Loss occurs.

Accordingly, the present invention has been made to solve the above problems of the prior art, and through the development of a method for producing a sheet electrode, which is easy to control the thickness of the carbon-PTFE sheet electrode while using a binder, in particular PTFE, and excellent electrolyte impregnation An object of the present invention is to provide a carbon-polytetrafluoroethylene-hydrophilic binder sheet electrode for an electric double layer capacitor having excellent electrical and mechanical properties, and a method of manufacturing the same.

The present invention for achieving the above object is a hydrophilic binder solution manufacturing step of dissolving a hydrophilic binder in a solvent to form a hydrophilic binder solution; A paste composition forming step of kneading a mixture of activated carbon, a conductive material, polytetrafluoroethylene (PTFE) and the hydrophilic binder solution to form a paste composition; A sheet forming step of rolling the paste composition to form a sheet; In addition, the method of manufacturing a carbon-polytetrafluoroethylene-hydrophilic binder sheet electrode for an electric double layer capacitor comprising a bonding step of adhering the sheet to a metal foil using a conductive adhesive material.

The present invention provides a sheet electrode for an electric double layer capacitor in which an electrode sheet is bonded to an upper surface of a metal foil using a conductive adhesive, wherein the sheet comprises a hydrophilic binder solution formed by dissolving a hydrophilic binder in a solvent, activated carbon, and conductive material. A technical gist of the carbon-polytetrafluoroethylene-hydrophilic binder sheet electrode for an electric double layer capacitor formed by rolling a paste composition kneaded with ash and PTFE (PolyTetraFluoroEthylene) is rolled.

Here, the metal foil is preferably an etched metal foil.

The hydrophilic binder is selected from the group consisting of Carboxymethylcellulose (CMC), Polyvinylalcohol (PVA), Polyvinylpyrrolidone (PVP) and Polyacrylic acid (PAA), and the solvent is water, n-methyl-2-pyrrolidone (NMP), Preferably at least one of the alcohols is selected.

The conductive material is preferably at least one selected from the group consisting of carbon black, graphite, carbon nanofibers, carbon nanotubes, and metal powders.

It is preferable that the said activated carbon has a specific surface area of 500-2500 m <2> / g.

In the hydrophilic binder solution manufacturing step, it is preferable to mix in a proportion of 90 to 99 parts by weight of the hydrophilic binder with respect to 1 to 10 parts by weight of the solvent.

In the paste composition forming step, it is preferable to mix 80 to 92 parts by weight of activated carbon, 5 to 10 parts by weight of a conductive material, 3 to 5 parts by weight of PTFE, and 0.1 to 5 parts by weight of a hydrophilic binder.

In the paste composition forming step, the dispersion medium is further mixed, the dispersion medium is preferably isopropyl alcohol.

The sheet forming step is to form a sheet while reducing the electrode thickness using a roll press, the thickness of the sheet is preferably 80 ~ 250㎛.

Accordingly, it is easy to control the thickness of the carbon-PTFE sheet electrode while using a binder, in particular PTFE, and has excellent advantages in electrical and mechanical properties through the development of a sheet electrode manufacturing method excellent in electrolyte impregnation.

The present invention according to the above configuration, while using a binder, in particular PTFE, it is easy to control the thickness of the carbon-PTFE sheet electrode, and the effect of excellent electrical and mechanical properties through the development of a sheet electrode manufacturing method excellent in electrolyte impregnation properties have.

Hereinafter, preferred embodiments of the present invention will be described in detail.

The carbon-polytetrafluoroethylene-hydrophilic binder sheet electrode method for an electric double layer capacitor according to the present invention is largely composed of a hydrophilic binder solution preparing step, a paste composition forming step, a sheet forming step, and an adhesive step.

First, the step of preparing a hydrophilic binder solution will be described.

In the preparation of the hydrophilic binder solution, the hydrophilic binder may be selected from one or more of the group consisting of Carboxymethylcellulose (CMC), Polyvinylalcohol (PVA), Polyvinylpyrrolidone (PVP), and Polyacrylic acid (PAA), and may be used as a hydrophilic binder using a beaker or a general experimental container. Is preferably dissolved in water or a solvent in which the ratio of water and alcohol is contained in a weight ratio of 80 to 99: 1 to 20.

At this time, the weight ratio of the hydrophilic binder and the solvent is adjusted to a ratio of 90 to 99: 1 to 10 and stirred at a temperature of 10 to 90 ° C to dissolve, and the final solution is preferably adjusted to a viscosity within the range of 500 to 2000 cp. .

Next, the paste composition forming step is performed. In the forming of the paste composition, a mixture is prepared by mixing activated carbon, a conductive material, and PTFE in a solvent containing a hydrophilic binder, and rolling the mixture to prepare a sheet.

The weight ratio of the active material, the conductive material, the PTFE and the hydrophilic binder contained in the final manufactured electrode is preferably adjusted to the amount of each component so that the ratio of 80 ~ 92: 5 ~ 10: 3 ~ 5: 0.1 ~ 5.

The activated carbon may have a specific surface area in the range of 500 to 2,500 m 2 / g. Although it does not restrict | limit especially, It is more preferable to exist in the range of 1,000-2,000 m <2> / g. This is because the filling density of the electrode is lowered at 1,000 m 2 / g or less, and the capacity per electrode volume is lowered. Because it increases.

The conductive material may be one or more selected from the group consisting of carbon black, graphite, hard carbon, carbon nanofibers, carbon nanotubes, and metal powders, and in the case of powder, particles having a size of 10 to 900 nm may be used. It is preferably a size of 200 ~ 600nm. In addition, the carbon black, graphite (carbon) or carbon nanofibers, carbon nanotubes can be used that the metal is coated. The coating is preferably coated by electroless plating.

The PTFE (PolyTetraFluoroEthylene) can be used in the particle size of 0.1 ~ 0.5㎛ and the solids alone or the solids of PTFE (emulsion) dispersed in water, xylene (isoylene), isopropyl alcohol, toloene, butyl acetate, methyl alcohol, etc. ) PTFE can be used. PTFE has excellent chemical, heat resistance, and mechanical strength, and as the electrode is composed, the rolling of the fiber resin of PTFE develops and the active material, especially activated carbon and the conductive material, adheres to the inside of the network structure. Increasing the filling density and at the same time reducing the contact resistance with the active material or conductive material improves the electrical properties of the electrode. In addition, in the present invention, since the weight ratio of PTFE in the electrode can be lowered to within 3 to 5%, there is an advantage of increasing the total capacity per electrode volume by increasing the packing density of the active material.

When the paste is prepared using the mixture consisting of the activated carbon, the conductive material, the PTFE and the hydrophilic binder, the mixture can be kneaded with an impeller in a ball mill or a container while maintaining a constant viscosity, and the mixture is further mixed with a dispersion medium if necessary. The paste can be prepared into a composition.

The dispersion medium is not limited as long as it can disperse the mixture evenly, and particularly preferably isopropyl alcohol. Isopropyl alcohol is used because it prevents agglomeration between binders, in particular PTFE, and promotes the change of PTFE resin into a fibrous network structure.

Next, as the sheet forming step proceeds, as a method of manufacturing a sheet by rolling using the prepared paste, it is preferable to repeat a plurality of folding and re-rolling of the sheet after rolling. This is because in the initial rolling, the binder resin, especially the fiber resin of PTFE, increases to form a network structure, and as the rolling progresses repeatedly, the dense network structure of the fiber resin of PTFE develops, thereby improving the electrical and mechanical properties of the electrode. The rolling is more preferably repeated 10 times or more and 50 times or less, and the thickness of the electrode can be adjusted within the range of 80 ~ 250㎛. The rolling may be controlled by using rolls of the same radius up and down alone, and also in the manner of using the rolls of the same radius up and down, and several rolls continuously roll the electrodes to adjust the thickness.

Next, the adhesion step is performed, in the adhesion step, it is possible to adhere the sheet of 80 ~ 250㎛ using a conductive adhesive on the surface of the metal foil, especially aluminum foil, and to the surface of the metal foil by coating or spraying the conductive adhesive It is possible to use after coating with a thickness of ˜30 μm. The conductive adhesive is not particularly limited to a mixture of carbon black, graphite, nanocarbon tubes and nanocarbon fibers, graphene, and a solvent including at least one carbon and a binder.

The sheet bonded using the conductive adhesive is manufactured by rolling so that the thickness of the bonded sheet may be reduced within a range of 1 to 5% using a hot roll press in which the roll surface maintains 50 to 150 ° C. do.

The electrode to which the sheet or sheet is bonded to the surface of the metal foil using a conductive adhesive is preferably manufactured by the above-described manufacturing method, and is not limited to an electric double layer capacitor, but a hybrid capacitor, a primary battery, a lithium secondary battery, a solar cell, Or it can be usefully used as an electrode of an energy storage device, such as a fuel cell, the shape of the energy storage power source can be used regardless of the form, such as coin cells, cylindrical cells, square cells.

Hereinafter, a preferred embodiment of the present invention will be described. However, the following examples are provided only to explain in more detail than the present invention, it is to be understood that does not limit the technical scope of the present invention.

&Lt; Example 1 >

50 ml of a mixture of PVP, which is a hydrophilic binder, and distilled water, which is water, in a weight ratio of 5:95 is poured into a 100 ml beaker, followed by stirring until it is sufficiently dissolved.

MSP20 (manufactured by Kwansuh Thermo Chemical, Japan), Super-p Black (Belgium, MMM carbon), PTFE (PolyTetraFluoroEthylene) was used for sheet production. MSP20: Super- A paste was prepared by kneading 10 g of the mixture with 1 g of isopropyl alcohol so that the weight ratio of P: PTFE: PVP was 84.9: 10: 5: 0.1. The resulting paste was rolled through a rolling roll to prepare a sheet. At this time, the process of folding the sheet in half and rolling again was repeated five times to produce 200 μm, and then rolling while reducing the rolling roll interval step by step to finally prepare a sheet having a thickness of 100 μm.

<Example 2>

50 ml of a hydrophilic binder PVP and distilled water in a 5:95 weight ratio were injected into a 100 ml beaker, followed by stirring until sufficient dissolution.

MSP20 (manufactured by Kwansuh Thermo Chemical, Japan), Super-p Black (Belgium, MMM carbon), PTFE (PolyTetraFluoroEthylene) was used for sheet production. MSP20: Super- A paste was prepared by kneading 10 g of the mixture with 1 g of isopropyl alcohol such that the weight ratio of P: PTFE: PVP was 84: 10: 5: 1. The resulting paste was rolled through a rolling roll to prepare a sheet. At this time, the process of folding the sheet in half and rolling again was repeated 5 times to prepare 200 μm, and then rolling while reducing the rolling roll interval step by step to prepare a sheet having a thickness of 100 μm.

<Example 3>

50 ml of a hydrophilic binder PVP and distilled water in a 5:95 weight ratio were injected into a 100 ml beaker, followed by stirring until sufficient dissolution.

MSP20 (manufactured by Kwansuh Thermo Chemical, Japan), Super-p Black (Belgium, MMM carbon), PTFE (PolyTetraFluoroEthylene) was used for sheet production. MSP20: Super- A paste was prepared by kneading 10 g of the mixture with 1 g of isopropyl alcohol such that the weight ratio of P: PTFE: PVP was 82: 10: 5: 3. The resulting paste was rolled through a rolling roll to prepare a sheet. At this time, the process of folding the sheet in half and rolling again was repeated 5 times to prepare 200 μm, and then rolling while reducing the rolling roll interval step by step to finally prepare a sheet having a thickness of 90 μm.

<Example 4>

50 ml of a hydrophilic binder PVP and distilled water in a 5:95 weight ratio were injected into a 100 ml beaker, followed by stirring until sufficient dissolution.

MSP20 (manufactured by Kwansuh Thermo Chemical, Japan), Super-p Black (Belgium, MMM carbon), PTFE (PolyTetraFluoroEthylene) was used for sheet production. MSP20: Super- A paste was prepared by kneading 10 g of the mixture with 1 g of isopropyl alcohol so that the weight ratio of P: PTFE: PVP was 80: 10: 5: 5. The resulting paste was rolled through a rolling roll to prepare a sheet. At this time, the sheet was folded in half and rolled again 5 times to prepare 200 μm, and then rolling while reducing the rolling roll interval step by step to prepare a sheet having a thickness of 90 μm.

Comparative Example

In the comparative example, when the hydrophilic binder was not added, the activated carbon was MSP20 (Specific Surface Area 2,000 / g, Japan, KK), and the conductive material was Super-p Black (manufactured by MMM Carbon, Belgium) and PTFE. (PolyTetraFluoroEthylene) was used, and a paste was prepared by kneading 10 g of the mixture with 1 g of isopropyl alcohol such that the weight ratio of MSP20: Super-P: PTFE was 85: 10: 5. The resulting paste was rolled through a rolling roll to prepare a sheet. At this time, the process of folding the sheet in half and rolling again was repeated 5 times to prepare 200 μm, and then rolling while reducing the rolling roll interval step by step to prepare a sheet having a thickness of 100 μm.

Next, the physical properties of each sheet and the cell using the sheet in the Examples and Comparative Examples were evaluated to evaluate the electrochemical properties, the evaluation method is as follows.

<Experimental Example>

(a) Thickness deviation

The thickness deviation of the prepared sheet was measured per 2 cm 2 of the 10 cm 2 size sheet using a thickness gauge and measured 20 times, after calculating the total average value showed a ± deviation.

(b) electrode density

After the sheet was vacuum dried at 150 ° C. under a vacuum of 0.1 torr for 12 hours, the sheet mass divided by the volume of the sheet outline was calculated as the density.

(c) electrolyte impregnation

The sheet was vacuum dried at 150 ° C. under a vacuum of 0.1 torr for 12 hours, and then 1 μl of 1.4 M (Mole) TEABF4 (tetra-ethyl-ammonium-tetra-fluoro) was added at a dew point temperature of 70 ° C. -borate) was measured by immersing the propylene carbonate (PC) electrolyte in the sheet and measuring the time when the electrolyte completely disappeared from the surface.

(d) preparation of coin cells

Sheets of each thickness were cut into 21 mm, and then inserted into the sheet A / separator / sheet B sequence using Celgard 3501 (manufactured by Celgard, USA) as a separator inside a coin cell (22 mmФ x 3.2 mmt). After impregnating 1.4M TEABF4 dissolved electrolyte in the PC and assembled a coin cell for an electric double layer capacitor.

(e) Determination of specific capacity per weight of activated carbon

The capacitance of the electric double layer capacitor was charged and discharged by a constant current method in a charge / discharge tester (MACCOR, model name MC-4). The drive voltage was measured under a condition of 2 mA / cm 2 at a voltage of 0 to 2.5 V. The capacitance of the electric double layer capacitor was calculated by the following equation in the time-voltage curve at the third constant current discharge.

C (capacitance, F) = dt? I / dV. (One)

Specific capacity (F / g) per weight of activated carbon represents values obtained by dividing the capacitance calculated in the above formula (1) by the weight of activated carbon in both electrodes.

(f) electrode resistance

The internal resistance of the electric double layer capacitor was measured using an impedance analyzer (Zahner IM6) after the third constant current discharge. The internal resistance behavior was performed in the frequency range of 100 Hz to 2.5 MHz, and the numerical values specified in Examples and Comparative Examples in the present invention represent values obtained by multiplying the AC resistance value at 1 Hz by the electrode area.

The measurement results are shown in Table 1 below.

<Measurement result>

As shown in Table 1 above, it can be seen that in the examples including PVP, the effect of reducing the electrode thickness and the effect of electrolyte impregnation were observed in comparison with the comparative example containing no PVP as a hydrophilic binder.

Compared with the comparative example, in the Example whose PVP content is 1.0% weight ratio or more, it turns out that the electrode thickness tends to decrease, and it turns out that electrolyte impregnation property increases as PVP content increases sequentially. Electrode resistance indicates little change in cell resistance when the PVP content is about 1.0%, but the cell resistance increases when the electrode content is higher and the cell specific capacity decreases.

From these results, when hydrophilic PVP is used for the electrode using the affinity PTFE binder, it is thought that as the content increases, PVP relaxes the network structure of PTFE, thereby obtaining a sheet even at a smaller electrode thickness than in the rolling process through a roll press. Even when the electrode density is equal or slight increase, it is judged that the electrode wettability of the electrolyte is improved by the influence of the hydrophilic binder.

As described above, the electrode manufacturing method according to the present invention, in addition to the electric double layer capacitor, can be used as the electrode manufacturing method of a hybrid capacitor, a primary battery, a lithium secondary battery, a solar cell or a fuel cell, and also the electrode manufacturing of the energy storage device It can be used without being limited to the method.

Claims (13)

Preparing a hydrophilic binder solution by dissolving the hydrophilic binder in a solvent to form a hydrophilic binder solution;
A paste composition forming step of kneading a mixture of activated carbon, a conductive material, polytetrafluoroethylene (PTFE) and the hydrophilic binder solution to form a paste composition;
A sheet forming step of rolling the paste composition to form a sheet; And,
A method of manufacturing a carbon-polytetrafluoroethylene-hydrophilic binder sheet electrode for an electric double layer capacitor, comprising: adhering the sheet to a metal foil using a conductive adhesive. The method according to claim 1, wherein the metal foil is an etched metal foil. 10. A method of manufacturing a carbon-polytetrafluoroethylene-hydrophilic binder sheet electrode for an electric double layer capacitor. The method of claim 1, wherein the hydrophilic binder, CMC (Carboxymethylcellulose), polyvinylalcohol (PVA), polyvinylpyrrolidone (PVP) and at least one selected from the group consisting of PAA (Polycrylicacid) carbon-poly for an electric double layer capacitor Tetrafluoroethylene-hydrophilic binder sheet electrode manufacturing method. 5. The carbon-polytetrafluoroethylene-hydrophilic binder sheet electrode for an electric double layer capacitor according to claim 4, wherein the solvent is selected from at least one of water, n-methyl-2-pyrrolidone (NMP) and alcohol. Manufacturing method. The method of claim 1, wherein the conductive material is selected from the group consisting of carbon black, graphite, carbon nanofibers, carbon nanotubes, and metal powders. Method for producing a carbon-polytetrafluoroethylene-hydrophilic binder sheet electrode for a double layer capacitor. The method of claim 5, wherein the activated carbon has a specific surface area of 500 to 2500 m 2 / g. [Claim 6] The carbon-polytetrafluoroethylene-hydrophilic binder for an electric double layer capacitor according to claim 5, wherein in the preparation of the hydrophilic binder solution, the hydrophilic binder is mixed at a ratio of 90 to 99 parts by weight with respect to 1 to 10 parts by weight of the solvent. Sheet electrode manufacturing method. The method of claim 5, wherein the paste composition forming step,
Carbon-polytetrafluoroethylene-hydrophilic binder sheet for electric double layer capacitors, characterized in that 80 to 92 parts by weight of activated carbon, 5 to 10 parts by weight of conductive material, 3 to 5 parts by weight of PTFE, and 0.1 to 5 parts by weight of hydrophilic binder. Electrode manufacturing method. The method of claim 5, wherein the forming of the paste composition comprises further dispersing a dispersion medium. 7. The method of manufacturing a carbon-polytetrafluoroethylene-hydrophilic binder sheet electrode for an electric double layer capacitor. The method according to claim 9, wherein the dispersion medium is isopropyl alcohol. 10. The method of manufacturing a carbon-polytetrafluoroethylene-hydrophilic binder sheet electrode for an electric double layer capacitor. [Claim 6] The carbon-polytetrafluoroethylene for an electric double layer capacitor according to claim 5, wherein the sheet forming step forms a sheet while reducing the electrode thickness using a roll press, wherein the sheet has a thickness of 80 to 250 µm. -Hydrophilic binder sheet electrode manufacturing method. In the sheet electrode for electric double layer capacitors in which the electrode sheet is bonded to the upper surface of the metal foil by using a conductive adhesive material,
The sheet is formed by rolling a paste composition obtained by mixing a hydrophilic binder solution formed by dissolving a hydrophilic binder in a solvent, activated carbon, a conductive material, and PTFE (PolyTetraFluoroEthylene). Polytetrafluoroethylene-hydrophilic binder sheet electrode. In the sheet electrode for electric double layer capacitors in which the electrode sheet is bonded to the upper surface of the metal foil by using a conductive adhesive material,
The sheet is formed by rolling a paste composition kneaded by mixing a hydrophilic binder solution formed by dissolving a hydrophilic binder in a solvent, activated carbon, a conductive material, and PTFE (PolyTetraFluoroEthylene),
The paste composition is 80 to 92 parts by weight of activated carbon, 5 to 10 parts by weight of a conductive material, 3 to 5 parts by weight of PTFE, 0.1 to 5 parts by weight of a hydrophilic binder, carbon-polytetrafluoro for an electric double layer capacitor, characterized in that Ethylene-hydrophilic binder sheet electrode.