JPH07283084A - Electric double layer capacitor and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a highly reliable electric double layer capacitor having high decomposition voltage and low inner resistance in which leakage of electrolyte is prevented. CONSTITUTION:Positive and negative electrodes 1, 2 are formed of active carbon particles and a composite gel prepared by sol-gel method using silica gel and sulfuric acid. Current collecting layers 3, 4 are then formed on one sides thereof by plasma spraying stainless steel. The positive and negative electrodes 1, 2 are then opposed each other through an electrolyte 5 employing the composite gel. The upper member 6 (sealing plate) and a lower members 7(case) of the casing are then caulked through a polypropylene packing 8 thus constituting a coin type electric double layer capacitor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an all-solid-state small-sized large-capacity electric double layer capacitor and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, electric double layer capacitors have been widely used as a small power source for backing up a semiconductor memory. Further, there is a demand for the development of a more reliable capacitor with less self-discharge and no electrolyte leakage.

As a conventional technique in this field,
(A) A capacitor using a polycrystalline solid electrolyte having metal ion conductivity as the electrolyte is disclosed in, for example, Japanese Patent Laid-Open Publication No.
There is one proposed in the Japanese Patent Laid-Open No. 3-61053. This capacitor uses a solid electrolyte having copper ion conductivity as an electrolyte.

Further, as (B) an electrolytic solution in which an organic solvent in which an electrochemically stable electrolyte is dissolved is used and activated carbon powder is used as a polarizable electrode, for example, JP-A-49-682.
There is one proposed in Japanese Patent Publication No. 54. This capacitor uses an organic electrolytic solution in which a peralkyl salt of tetraalkylammonium is dissolved in an organic solvent such as propylene carbonate.

[0005]

In the electric double layer capacitor having the above-mentioned structure, when the polycrystalline solid electrolyte having metal ion conductivity as described in (A) above is used, the It is difficult to increase the withstand voltage of the capacitor because the decomposition voltage of the solid electrolyte of the crystal is low (0.6 V or less). Moreover, the electric conductivity of the solid electrolyte is not sufficiently large, and therefore the discharge characteristics with a small internal resistance. There is a problem that it is difficult to obtain an excellent capacitor.

Further, when the organic electrolytic solution as described in (B) above is used, it is difficult to completely prevent the electrolytic solution from leaking, and a capacitor having a high reliability in a wide temperature range can be obtained. There was a problem that it was difficult to manufacture.

In order to solve the above problems, it is an object of the present invention to provide a highly reliable electric double layer capacitor having a higher decomposition voltage, a smaller internal resistance, and no leakage, and a method for manufacturing the same. To do.

[0008]

In order to achieve the above object, the electric double layer capacitor of the present invention has a polarizable electrode on the positive electrode side and a negative electrode side via an electrolyte using a composite gel consisting of a dopant and a matrix gel. The polarizable electrodes are opposed to each other, each polarizable electrode is provided with a collector made of a metal or a conductive resin, and activated carbon is used for the polarizable electrodes on the positive electrode side and the negative electrode side.

In the above structure, the matrix gel is preferably at least one selected from silica gel, alumina gel, and titania gel. Next, the first method for producing an electric double layer capacitor of the present invention is to prepare a composite gel as an electrolyte by hydrolyzing a mixed sol composed of a dopant and a metal alkoxide, and to prepare a composite gel prepared from the mixed sol. Active carbon is mixed to form a polarizable electrode on the positive electrode side and a polarizable electrode on the negative electrode side, and a collector made of a metal or a conductive resin is formed on each of the polarizable electrodes, and the positive electrode side is formed through the electrolyte. The polarizable electrode and the polarizable electrode on the negative electrode side are provided so as to face each other.

In the second method for producing an electric double layer capacitor of the present invention, a composite gel as an electrolyte is prepared by hydrolyzing a mixed sol composed of a dopant and a metal alkoxide, and the composite gel is prepared from the dopant, the metal alkoxide and activated carbon. To form a polarizable electrode on the positive electrode side and a polarizable electrode on the negative electrode side by hydrolyzing the mixed sol, and to form a current collector made of a metal or a conductive resin on each of the polarizable electrodes. The polarizable electrode on the side of the positive electrode and the polarizable electrode on the side of the negative electrode are provided so as to face each other.

In the third method for producing an electric double layer capacitor of the present invention, a composite gel as an electrolyte is prepared by hydrolyzing a mixed sol composed of a dopant and a metal alkoxide, and a composite prepared from the mixed sol. A gel is mixed with activated carbon and a binder to form a polarizable electrode on the positive electrode side and a polarizable electrode on the negative electrode side, and each of the polarizable electrodes is press-molded together with a current collector made of a metal or a conductive resin, and the electrolyte is used. The polarizable electrode on the positive electrode side and the polarizable electrode on the negative electrode side are provided so as to face each other via the above.

In the first, second or third production method, the mixed sol is further mixed with at least one organic compound selected from ethylene carbonate, propylene carbonate, gamma-butyl lactone, dimethylformamide, and dimethylsulfoxide. It is preferable to add a solvent.

The fourth method for producing an electric double layer capacitor of the present invention is to prepare a composite gel as an electrolyte by hydrolyzing a mixed sol composed of a dopant, a metal alkoxide and an organic solvent, and prepare the composite gel from the mixed sol. After mixing the prepared composite gel, activated carbon, and a binder, the mixture is applied to a metal current collector to form a polarizable electrode on the positive electrode side and a polarizable electrode on the negative electrode side, and the polarizable electrode on the positive electrode side through the electrolyte. And a polarizable electrode on the negative electrode side are provided to face each other.

The fifth method for producing an electric double layer capacitor of the present invention is the positive electrode by immersing a metal current collector in a mixed sol composed of a dopant, a metal alkoxide, an organic solvent and activated carbon to hydrolyze the sol. Side polarizable electrode and negative side polarizable electrode are formed, and a mixed sol consisting of a dopant, a metal alkoxide and an organic solvent is applied to each of the polarizable electrodes and hydrolyzed to produce a composite gel as an electrolyte. The polarizable electrode on the positive electrode side and the polarizable electrode on the negative electrode side are provided to face each other via the electrolyte.

The sixth method of manufacturing an electric double layer capacitor of the present invention is to form a metal current collector layer on an activated carbon fiber cloth and then mix the activated carbon fiber cloth with a dopant, a metal alkoxide and an organic solvent. To form a polarizable electrode on the positive electrode side and a polarizable electrode on the negative electrode side by hydrolysis, and apply the mixed sol to each of the polarizable electrodes to hydrolyze to produce a composite gel as an electrolyte. The polarizable electrode on the positive electrode side and the polarizable electrode on the negative electrode side are provided so as to face each other with the electrolyte interposed therebetween.

In the first to sixth manufacturing methods,
It is preferable to further mix fine graphite particles with the mixed sol used for the polarizable electrode. Further, in the electric double layer capacitor of the present invention or the first to sixth manufacturing methods thereof, the dopant is hydrochloric acid, sulfuric acid, heteropolyacid, perchloric acid, an acid or alkali of potassium hydroxide, tetraethylammonium perchlorate, And at least one selected from tetraethylammonium borofluoride.

Further, in the electric double layer capacitor of the present invention or the first to sixth manufacturing methods thereof, the activated carbon is selected from phenol-based, pitch-based, and polyacrylonitrile (PAN) -based powdered or fibrous activated carbon. It is preferably at least one selected.

In the electric double layer capacitor of the present invention or the first to sixth manufacturing methods thereof, the metal used for the current collector is preferably at least one selected from aluminum, titanium and stainless steel. .

In the fourth to sixth production methods of the present invention, the organic solvent is at least one selected from ethylene carbonate, propylene carbonate, gamma-butyl lactone, dimethylformamide and dimethyl sulfoxide. It is preferable.

[0020]

According to the electric double layer capacitor of the present invention,
A polarizable electrode on the positive electrode side and a polarizable electrode on the negative electrode side are opposed to each other through an electrolyte using a composite gel composed of a dopant and a matrix gel, and each polarizable electrode is provided with a collector made of a metal or a conductive resin. By using activated carbon for the polarizable electrodes on the positive electrode side and the negative electrode side, the electric double layer capacity formed at the interface between the electrolyte ions of the composite gel and the activated carbon is utilized, so that the portion that deteriorates due to the electrochemical reaction may be used. In addition, the decomposition voltage is relatively high, the internal resistance can be reduced, and since the electrolytic solution is a gel, it is possible to provide a highly reliable electric double layer capacitor without leakage.

Further, according to the preferable constitution of the present invention in which the matrix gel is at least one selected from silica gel, alumina gel and titania gel, the chemical stability of the electric double layer capacitor is improved.

Next, according to the first manufacturing method, a mixed gel comprising a dopant and a metal alkoxide is hydrolyzed to prepare a composite gel as an electrolyte, and activated carbon is added to the composite gel prepared from the mixed sol. Mixed to form a polarizable electrode on the positive electrode side and a polarizable electrode on the negative electrode side, a collector made of a metal or a conductive resin is formed on each of the polarizable electrodes, and a component on the positive electrode side is formed through the electrolyte. By providing the polar electrode and the polarizable electrode on the negative electrode side to face each other, a polarizable electrode having a uniform composition can be obtained, and an electric double layer capacitor without leakage of the electrolytic solution can be manufactured.

Further, according to the second manufacturing method, a composite gel as an electrolyte is prepared by hydrolyzing a mixed sol composed of a dopant and a metal alkoxide, and a mixed sol composed of the dopant, the metal alkoxide and activated carbon is hydrolyzed. By decomposing, a polarizable electrode on the positive electrode side and a polarizable electrode on the negative electrode side are formed, and a collector made of a metal or a conductive resin is formed on each of the polarizable electrodes, and the positive electrode side is formed through the electrolyte. By providing the polarizable electrode and the polarizable electrode on the negative electrode side to face each other, a polarizable electrode having a uniform composition can be obtained, and an electric double layer capacitor without leakage of the electrolytic solution can be manufactured.

Further, according to the third manufacturing method, a composite gel as an electrolyte is prepared by hydrolyzing a mixed sol composed of a dopant and a metal alkoxide, and activated carbon and a bond are added to the composite gel prepared from the mixed sol. A polarizable electrode on the positive electrode side and a polarizable electrode on the negative electrode side are formed by mixing an agent, and each of the polarizable electrodes is press-molded together with a current collector made of a metal or a conductive resin, and the positive electrode is interposed via the electrolyte. Side polarizable electrode and the negative side polarizable electrode face each other to provide a polarizable electrode having a uniform composition, and an electric double layer capacitor without leakage of electrolyte solution can be easily manufactured. it can.

In the first, second or third production method, the mixed sol is further mixed with at least one organic solvent selected from ethylene carbonate, propylene carbonate, gamma-butyl lactone, dimethylformamide and dimethylsulfoxide. According to the preferred configuration of the present invention in which
It is convenient because it is as chemically stable as it is above 00 ° C.

Further, according to the fourth manufacturing method, a composite gel as an electrolyte is prepared by hydrolyzing a mixed sol composed of a dopant, a metal alkoxide and an organic solvent, and the composite gel prepared from the mixed sol, After mixing activated carbon and a binder, the mixture is applied to a metal current collector to form a polarizable electrode on the positive electrode side and a polarizable electrode on the negative electrode side, and the polarizable electrode on the positive electrode side and the negative electrode side are separated via the electrolyte. By providing the polar electrodes facing each other, the mixture of the composite gel, the activated carbon and the binder can be held on the metal current collector, so that the positive electrode and the negative electrode having a uniform composition can be obtained, and the internal resistance excellent in the current collecting ability can be obtained. A small and highly reliable electric double layer capacitor can be manufactured.

According to the fifth production method, the polarizable electrode on the positive electrode side is obtained by immersing a metal current collector in a mixed sol composed of a dopant, a metal alkoxide, an organic solvent and activated carbon to hydrolyze the sol. And a polarizable electrode on the negative electrode side is formed, and a mixed sol consisting of a dopant, a metal alkoxide and an organic solvent is applied to each of the polarizable electrodes and hydrolyzed to produce a composite gel as an electrolyte, which is then passed through the electrolyte. By providing the polarizable electrode on the positive electrode side and the polarizable electrode on the negative electrode side by side so that the composite sol can be held on the metal current collector, a positive electrode and a negative electrode having a uniform composition can be obtained, A highly reliable electric double layer capacitor with excellent internal resistance can be manufactured.

According to the sixth manufacturing method, after the metal current collector layer is formed on the activated carbon fiber cloth, the activated carbon fiber cloth is dipped in a mixed sol composed of a dopant, a metal alkoxide and an organic solvent for hydrolysis. To form a polarizable electrode on the positive electrode side and a polarizable electrode on the negative electrode side by applying the mixed sol to each of the polarizable electrodes and hydrolyzing to produce a composite gel as an electrolyte, Since the polarizable electrode on the positive electrode side and the polarizable electrode on the negative electrode side are provided to face each other through the composite gel can be held on the metal current collector, a positive electrode and a negative electrode having a uniform composition can be obtained. It is possible to manufacture a highly reliable electric double layer capacitor having excellent electric power and small internal resistance.

Further, in the first to sixth manufacturing methods, according to the preferable constitution of the present invention in which graphite fine particles are further mixed with the mixed sol used for the polarizable electrode, the polarizable electrode is added by adding the graphite fine particles. Since it is possible to reduce the electric resistance of the electric double layer capacitor, it is possible to manufacture a highly reliable electric double layer capacitor having a small internal resistance.

In the electric double layer capacitor of the present invention or the first to sixth manufacturing methods thereof, the dopant is hydrochloric acid, sulfuric acid, heteropolyacid, perchloric acid, potassium hydroxide acid or alkali, or tetraethyl perchlorate. According to the preferable configuration of the present invention, which is at least one selected from ammonium and tetraethylammonium borofluoride, the electrical conductivity can be increased in an acid or alkaline solution, the internal resistance of the capacitor can be reduced, and An organic electrolytic solution using an electrolyte salt such as tetraethylammonium chlorate or tetraethylammonium borofluoride has a high decomposition voltage and can increase the withstand voltage of the capacitor.

Further, in the electric double layer capacitor of the present invention or the first to sixth manufacturing methods thereof, the activated carbon is selected from phenol type, pitch type and polyacrylonitrile (PAN) type powdered or fibrous activated carbon. According to the preferred constitution of the present invention, which is at least one of the above, the activated carbon has a specific surface area which is more than double the specific surface area of 2,000 m ² g ^-1 compared to coconut shell coal, and the pore diameter is in the range of 2 to 4 nm. The double layer capacity can be increased.

In the electric double layer capacitor of the present invention or the first to sixth manufacturing methods thereof, the metal used for the current collector is at least one selected from aluminum, titanium and stainless steel. According to the preferable constitution, the electrochemical stability of the polarizable electrode, especially the positive electrode is improved.

In the fourth to sixth production methods of the present invention, the organic solvent is at least one selected from ethylene carbonate, propylene carbonate, gamma-butyl lactone, dimethylformamide, and dimethyl sulfoxide. According to the preferred constitution of (1), these organic solvents have a high boiling point of 200 ° C. or higher and are chemically stable, which is convenient.

[0034]

EXAMPLES In this example, the gel matrix produced by hydrolysis of a metal alkoxide (so-called sol-gel method) is preferably chemically or physically stable silica gel, alumina gel, or titania gel.

The sol-gel method is a method in which a lower alkoxide of a sol-like metal is hydrolyzed, gelled, and heated to form glass or ceramics.
Specific examples of typical metal alkoxides include silicon lower alkoxides such as silicon methoxide and ethoxide, aluminum lower alkoxides such as aluminum methoxide and ethoxide, and titanium lower alkoxides such as titanium methoxide and ethoxide. There are kinds. Further, water and / or methanol, ethanol, propanol or ethylene glycol of a dihydric alcohol is used as the dispersion medium of the sol, and hydrochloric acid or ammonia is usually used as the hydrolysis catalyst.

Further, formamide or dimethylformamide may be used as a drying control agent for preventing the generation of cracks and foaming which occur when the gel is dried. In this example, the amount of the dopant used is 0.0 in terms of molar ratio with respect to the composite gel.
It is preferably about 3 to 2.00.

In the present embodiment, the gelling reaction temperature is usually in the range of room temperature to 80 ° C. in the system containing the aqueous solution, and in the range of 100 to 130 ° C. in the system containing the organic solvent. The gel used in this example is preferably in a bulk form containing an electrolyte and activated carbon. Further, as another form, fine particles are preferable, and more specifically, a particle size of 0.5 to 200 μm is preferable. Further, as another form, a thin film is preferable, and more specifically, a film having a thickness of about 0.1 to 3 μm is preferable.

The activated carbon used as the polarizable electrode in this embodiment is not particularly limited, and various activated carbons can be used. The form of the activated carbon is preferably in the form of fine particles, and more specifically, the form having a particle size of 5 to 100 μm is preferable. It is also preferable to use a fibrous material. In particular, phenol-based, pitch-based, polyacrylonitrile (PAN) -based powdered or fibrous activated carbon has a specific surface area of 2000 m ^{2 which is} more than twice that of palm shell coal.
It is preferable since the pore size can be increased to g ⁻¹ and the pore size can be controlled in the range of 2 to 4 nm, and the double layer capacity can be increased.
The addition amount is preferably 30 to 80 wt% with respect to the composite gel.

The fine graphite particles used in this example preferably have a submicron particle size. The addition amount is preferably 5 to 10 wt% with respect to the composite sol. The metal current collector used in this embodiment is preferably aluminum, titanium, stainless steel, or the like, which is electrochemically stable in the positive electrode, and the form thereof is preferably mesh or fiber cloth. Further, as the current collector made of a conductive resin, it is preferable to use paste / thin film graphite / acrylic resin, graphite / polyethylene resin, or the like in which graphite is dispersed.

As the binder used in this embodiment, polyvinyl alcohol, fluororesin and the like can be used, but fluorocarbon resin having strong binding force and chemically stable, for example, tetrafluoroethylene resin is particularly preferable. The addition amount is preferably 0.1 to 5 wt% with respect to the mixture containing the gel.

The activated carbon fiber cloth used in this example is a cloth-like raw material resin carbonized and activated to be activated carbonized.
Hereinafter, specific examples will be described.

(Example 1) Output of composite gel as electrolyte
Evolving composition is Si (OEt) in molar ratio_Four, Ethan
Leu, water, sulfuric acid (dopant) 1: 5: 10: 0.1
Stir at room temperature for 30 minutes and gel at a temperature of 60 ° C
It was The electrical conductivity of this gel is 4 × 10 at room temperature. ^-1Scm^-1
Met. The gel produced in this way is crushed into
The particles were 30 μm in diameter. Use these particles for 3 to
n · cm²Press molding with pressure of 10mm in diameter, thickness
A 0.3 mm tablet was prepared and used as an electrolyte.

The polarizable electrode has a specific surface area of 200.
0m ² g ^-1 phenolic activated carbon particles (average particle size 20μ
m) was used. In order to reduce the contact resistance between the composite gel particles and the activated carbon particles, the positive electrode and the negative electrode have both 50
The mixture having a weight ratio of 50 was press-molded at a pressure of 3 ton · cm ² to give a tablet having a diameter of 10 mm and a thickness of 1 mm. Further, one side of the positive electrode and the negative electrode is made of stainless steel by plasma spraying to have a thickness of 100 μm.
The current collecting layer was formed.

A coin-type electric double layer capacitor is constructed by using the tablet-shaped positive electrode, negative electrode and electrolyte prepared in this manner, and its schematic sectional view is shown in FIG. In FIG. 1, 1 is a positive electrode, 2 is a negative electrode, 3 and 4 are current collecting layers, 5
Is an electrolyte, 6 is an upper member, 7 is a lower member, and 8 is a packing.

In advance, the positive electrode 1 and the negative electrode 2 were opposed to each other via the electrolyte 5, and pressing was performed at a pressure of 100 Kgcm ^-2 ,
As shown in FIG. 1, the electrolyte 5, the positive electrode 1, and the negative electrode 2 are arranged, and the upper member 6 (sealing plate) and the lower member 7 of the casing are arranged.
The (case) was caulked and sealed through a polypropylene packing 8. Stainless steel was used as the constituent material of the upper member 6 and the lower member 7. In all the other examples below, the structure of the capacitor is the same as that shown in FIG. 1, and the upper member 6, the lower member 7 (case), and the packing 8 are the same as those in this embodiment. I was there.

The capacitor of this example was charged at 0.8 V and then discharged at a constant current of 10 μA to obtain a capacity of 0.5 F and an impedance of 8 ohms. Also, in an atmosphere of 70 ° C, it is always 0.
When 8 V was applied, the capacity reduction rate after 1000 hours with respect to the initial capacity was 11%. In addition, no electrolyte leakage was found in the samples used in the experiment. Other hydrochloric acid,
A capacitor showing almost the same characteristics as described above could be manufactured by using an acid such as heteropoly acid, perchloric acid, potassium hydroxide or an alkaline electrolyte. When a conductive resin made of graphite / acrylic resin is used for the current collecting layer,
The impedance was as large as 21 ohms, but the reliability was almost the same as that of this example.

Further, even if pitch-based or polyacrylonitrile (PAN) -based activated carbon particles were used in place of the phenol-based activated carbon particles, characteristics substantially equivalent to those of the capacitor of this embodiment were exhibited.

Further, in addition to silicon ethoxide, aluminum ethoxide or titanium ethoxide may be used with alumina or titania gel to produce a capacitor having the same characteristics as those of the present embodiment.

Further, even when the electrolyte 5 was held by a polypropylene separator having a thickness of 70 μm and used, a capacitor having characteristics substantially equivalent to those of this example could be produced.
On the other hand, the initial characteristics of the conventional coin-type capacitor having the same structure using sulfuric acid as the electrolyte were almost the same as those of the present example, but when 0.8 V was constantly applied in the atmosphere of 70 ° C., the initial capacity was 1000. Capacity decrease rate after time is 23%
Met. Also, in the sample used in the experiment, the electrolyte leakage was observed in 5%.

(Example 2) As a starting composition of a composite gel as an electrolyte, Si (OEt) ₄ , ethanol, water, propylene carbonate and tetraethylammonium perchlorate (dopant) are used in a molar ratio of 1: 5: 1: 1. : 0.
1 was stirred at room temperature for 30 minutes and gelled at a temperature of 60 ° C. Further, the gel was heated at 110 ° C. to evaporate water. The electrical conductivity of this gel is 6 × 10 ^-4 Scm ^-1 at room temperature.
Met. The gel thus produced was pulverized into fine particles having an average particle size of 30 μm. Use these particles for 3 to
Press molding was performed under a pressure of n · cm ² to prepare a tablet having a diameter of 10 mm and a thickness of 0.3 mm, which was used as the electrolyte 5.

The polarizable electrode has a specific surface area of 200
0m ² g ^-1 phenolic activated carbon particles (average particle size 20μ
m) was used. In order to reduce the contact resistance between the composite gel and the activated carbon particles, the positive electrode and the negative electrode were mixed in advance in a weight ratio of 50:50 and press-molded at a pressure of 3 ton · cm ² , and the diameter was 10 mm and the thickness was 10 mm. The tablet shape was 1 mm. Such mixing and pressing steps were performed in a dry atmosphere. Further, collector layers 3 and 4 made of aluminum and having a thickness of 100 μm were formed on one surface of each of the positive electrode and the negative electrode by plasma spraying.

Using the tablet-shaped positive electrode 1, negative electrode 2 and electrolyte 5 thus produced, a coin type electric double layer capacitor having the same structure as in Example 1 was produced. A series of steps for manufacturing the capacitor was performed in a dry atmosphere.

After charging this capacitor at 2.8 V, 10
Constant current discharge at μA, capacity 0.21F, impedance 2
Got 2 ohms. Also, it is always 2.8V in 70 ℃ atmosphere.
When applied, the capacity reduction rate after 1000 hours with respect to the initial capacity was 12%. In addition, no electrolyte leakage was found in the samples used in the experiment. Even if a system of other possible combinations of an organic solvent such as ethylene carbonate, gamma-butyl lactone, dimethylformamide or dimethylsulfoxide and an electrolyte salt such as tetraethylammonium perchlorate or tetraethylammonium borofluoride is used, It was possible to fabricate a capacitor exhibiting almost the same characteristics as described above.

When a conductive resin made of graphite / acrylic resin is used for the current collecting layer, the impedance is 39%.
The reliability was almost the same as that of the present embodiment although it was increased to ohms.

Further, even if the pitch-based or polyacrylonitrile (PAN) -based activated carbon particles were used in place of the phenol-based activated carbon particles, substantially the same characteristics as the capacitor of this embodiment were shown.

In addition to silicon ethoxide, aluminum ethoxide or titanium ethoxide may be used with alumina or titania gel to produce a capacitor having the same characteristics as those of this embodiment.

Further, even if the electrolyte 5 was held and used in a polypropylene separator having a thickness of 70 μm, a capacitor having characteristics substantially equivalent to those of this example could be produced.
On the other hand, although the initial characteristics of the coin-type capacitor of the same structure using the conventional electrolytic solution of tetraethylammonium perchlorate and propylene carbonate were almost the same as those of the present example, they were always under the atmosphere of 70 ° C. When 2.8 V was applied, the capacity reduction rate after 1000 hours was 29% with respect to the initial capacity. In addition, 2 of the samples used for the experiment
The electrolyte leakage was found in%.

(Example 3) As a starting composition of a composite gel as an electrolyte, Si (OEt) ₄ , ethanol, water, propylene carbonate and tetraethylammonium perchlorate (dopant) were used in a molar ratio of 1: 5: 1: 1. : 0.
1 was stirred at room temperature for 30 minutes and gelled at a temperature of 60 ° C. The gel thus produced was pulverized into fine particles having an average particle size of 30 μm. 3 tons using these particles
- press-molded at a pressure of cm ^2, and the electrolyte 5 prepared diameter 10 mm, thickness 0.3mm tablets.

Apart from the composite gel, 10 wt% graphite fine particles (average particle size 0.5 μm) based on the sol mixture
Was added, stirred at room temperature for 30 minutes, and gelled at a temperature of 60 ° C. Further, the gel was heated at 110 ° C. to evaporate water. The electrical conductivity of this gel is 1 x 10 ^-4 Scm at room temperature.
It was ^-1 . The gel thus produced was pulverized into fine particles having an average particle size of 30 μm and a specific surface area of 2000 m ² g.
^-1 Phenol-based activated carbon particles (average particle size 20 μm) were mixed at a weight ratio of 30:70 to form a polarizable electrode. In order to reduce the contact resistance between the electrolyte and the activated carbon particles that are the polarizable electrode, the positive electrode and the negative electrode were press-molded under a pressure of 3 ton · cm ² by mixing them in a weight ratio of 50:50 in advance, A tablet having a diameter of 10 mm and a thickness of 1 mm was prepared. Such mixing and pressing steps were performed in a dry atmosphere. Further, a current collecting layer 3 made of aluminum and having a thickness of 100 μm is formed on one surface of each of the positive electrode and the negative electrode by plasma spraying.
And 4 were formed.

By using the tablet-shaped positive electrode 1, negative electrode 2 and electrolyte 5 thus produced, a coin type electric double layer capacitor having the same structure as in Example 2 was produced.

After charging this capacitor at 2.8 V, 10
Constant current discharge at μA, capacity: 0.24F, impedance: 1
Got 6 ohms. Also, it is always 2.8V in 70 ℃ atmosphere.
When a voltage was applied, the capacity reduction rate after 1000 hours was 9% with respect to the initial capacity.

No electrolyte leakage was found in the samples used in the experiment. Even if a system of other possible combinations of an organic solvent such as ethylene carbonate, gamma-butyl lactone, dimethylformamide or dimethylsulfoxide and an electrolyte salt such as tetraethylammonium perchlorate or tetraethylammonium borofluoride is used, It was possible to fabricate a capacitor exhibiting almost the same characteristics as described above.

Further, even if pitch-based or polyacrylonitrile (PAN) -based activated carbon particles were used instead of the phenol-based activated carbon particles, the characteristics substantially equivalent to those of the capacitor of this embodiment were exhibited.

(Example 4) Production of composite gel as electrolyte
Evolving composition is Si (OEt) in molar ratio_Four, Ethan
Leu, water, sulfuric acid (dopant) 1: 5: 10: 0.1
Stir at room temperature for 30 minutes and gel at a temperature of 60 ° C
It was The electrical conductivity of this gel is 4 × 10 at room temperature. ^-1Scm^-1
Met. The gel produced in this way is crushed into
The particles were 30 μm in diameter. Use these particles for 3 to
n · cm²Press molding with pressure of 10mm in diameter, thickness
A 0.3 mm tablet was prepared and used as the electrolyte 5.

Separately from the composite gel, 50 wt% of phenol-based activated carbon particles (specific surface area: 2000 m ² g ^-1 , average particle size 20 μm) were added to the sol mixture.
After stirring for 0 minutes, a gel was formed at a temperature of 60 ° C. The electrical conductivity of this gel was 2 × 10 ^-1 Scm ^-1 at room temperature.
The composite gel produced in this way was crushed to obtain an average particle size of 30μ.
After the m of fine particles, and pressed at a pressure of 3 ton · cm ^2, to prepare a diameter 10 mm, thickness 1mm tablet-shaped positive electrode 1 and negative electrode 2. Further, one side of the positive electrode and the negative electrode is formed of stainless steel by a plasma spraying method to a thickness of 1
The current collecting layers 3 and 4 of 00 μm were formed.

Using the tablet-shaped positive electrode 1, negative electrode 2, and electrolyte 5 thus manufactured, a coin-type electric double layer capacitor having the same structure as in Example 1 was manufactured.

After charging this capacitor at 1.0 V, 10
Constant current discharge at μA, capacity 0.48F, impedance 6
Got an ohm. When 1.0 V was constantly applied in the atmosphere of 70 ° C., the capacity reduction rate after 1000 hours was 9% with respect to the initial capacity. In addition, no electrolyte leakage was found in the samples used in the experiment.

Other hydrochloric acid, heteropolyacid, perchloric acid,
A capacitor showing almost the same characteristics as in this example could be manufactured by using an acid or alkaline electrolyte of potassium hydroxide. When a conductive resin made of graphite / acrylic resin is used for the current collecting layer, the impedance is 11
The reliability was almost the same as that of the present embodiment although it was increased to ohms.

Further, even if the pitch-based or polyacrylonitrile (PAN) -based activated carbon particles were used instead of the phenol-based activated carbon particles, the same characteristics as those of the capacitor of this embodiment were shown.

(Example 5) As a starting composition of a composite gel as an electrolyte, Si (OEt) ₄ , ethanol, water, propylene carbonate and tetraethylammonium perchlorate (dopant) were used in a molar ratio of 1: 5: 1: 1. : 0.
1 was stirred at room temperature for 30 minutes and gelled at a temperature of 60 ° C. The electrical conductivity of this gel is 4 × 10 ^-1 Scm at room temperature.
It was ^-1 . The gel thus produced was pulverized into fine particles having an average particle size of 30 μm. 3t using this fine particle
It was press-molded at a pressure of on · cm ² to produce a tablet having a diameter of 10 mm and a thickness of 0.3 mm, which was used as the electrolyte 5.

Separately from the composite gel, 50 wt% of phenol-based activated carbon particles (specific surface area: 2000 m ² g ^-1 , average particle size 20 μm) were added to the sol mixture.
After stirring for 0 minutes, a gel was formed at a temperature of 60 ° C. Further, the gel was heated at 110 ° C. to evaporate water. The electrical conductivity of this gel was 9 × 10 ⁻⁴ Scm ⁻¹ at room temperature.
The gel thus produced is crushed to obtain an average particle size of 30 μm.
After the fine particles, and pressed at a pressure of 3 ton · cm ^2, to produce 10 mm, the positive electrode 1 and negative electrode 2 tablets shaped thickness 1mm diameter. Further, a thickness 10 made of stainless steel was formed on one surface of each of the positive electrode and the negative electrode by using a plasma spraying method.
0 μm current collecting layers 3 and 4 were formed.

Using the tablet-shaped positive electrode 1, negative electrode 2, and electrolyte 5 thus manufactured, a coin-type electric double layer capacitor having the same structure as in Example 1 was manufactured. A series of steps for manufacturing the capacitor was performed in a dry atmosphere.

After charging this capacitor at 2.8 V, 10
Constant current discharge at μA, capacity 0.22F, impedance 1
Got 9 ohms. Also, it is always 2.8V in 70 ℃ atmosphere.
Was applied, the capacity reduction rate after 1000 hours was 10% with respect to the initial capacity. In addition, no electrolyte leakage was found in the samples used in the experiment. Even if a system of other possible combinations of an organic solvent such as ethylene carbonate, gamma-butyl lactone, dimethylformamide or dimethylsulfoxide and an electrolyte salt such as tetraethylammonium perchlorate or tetraethylammonium borofluoride is used, It was possible to fabricate a capacitor exhibiting almost the same characteristics as described above.

When a conductive resin made of graphite / acrylic resin is used for the current collecting layer, the impedance is 28
The reliability was almost the same as that of the present embodiment although it was increased to ohms. Further, even if pitch-based or polyacrylonitrile (PAN) -based activated carbon particles were used in place of the phenol-based activated carbon particles, almost the same characteristics as the capacitor of this example were shown.

Example 6 As a starting composition of a composite gel which is an electrolyte, Si (OEt) ₄ , ethanol, and
Water and sulfuric acid (dopant) were stirred at room temperature for 30 minutes using 1: 5: 10: 0.1, and gelled at a temperature of 60 ° C. The electrical conductivity of this gel was 4 × 10 ^-1 Scm ^-1 at room temperature. The composite gel thus produced was pulverized into fine particles having an average particle size of 30 μm. 3 tons using these particles
-Pressing was carried out at a pressure of cm ² , and a tablet having a diameter of 10 mm and a thickness of about 150 μm was produced and used as the electrolyte 5.

Separately from the composite gel, 50 wt% of phenol-based activated carbon particles (specific surface area: 2000 m ² g ^-1 , average particle size 20 μm) with respect to the sol mixture and 2 w
After adding t% fluororesin as a binder and stirring, 6
Gelled at a temperature of 0 ° C. The composite gel thus prepared was crushed into fine particles having an average particle size of 30 μm,
Positive electrode 1 with a polarizable electrode after press-molding with a pressure of gcm ^-2
And the negative electrode 2 were produced.

The positive electrode 1 and the current collector 3 made of a stainless steel mesh or the negative electrode 2 and the current collector 4 which were preliminarily press-molded were superposed, and the whole was finally pressed at a pressure of 3 ton · cm ⁻² . The prepared mixture has a thickness of about 500 μm and a diameter of 10 mm.
And tablet.

By using the tablet-shaped positive electrode 1, negative electrode 2, and electrolyte 5 thus produced, a coin-type electric double layer capacitor having the same configuration as in Example 1 was produced.

After charging this capacitor at 1.0 V, 10
A constant current discharge was performed at μA to obtain a capacity of 0.2 F and an impedance of 3 ohms. When 1.0 V was constantly applied in the atmosphere of 70 ° C., the capacity reduction rate after 1000 hours was 9% with respect to the initial capacity. In addition, no electrolyte leakage was found in the samples used in the experiment. A capacitor having substantially the same characteristics as that of this example could be manufactured by using other hydrochloric acid, heteropolyacid, perchloric acid, potassium hydroxide acid or alkaline electrolyte. Furthermore, instead of phenol-based activated carbon particles, pitch-based, polyacrylonitrile (P
The characteristics similar to those of the capacitor of this example were exhibited even when the activated carbon particles of (AN) type were used.

Example 7 As a starting composition of a composite gel as an electrolyte, Si (OEt) ₄ , ethanol, and
Water, propylene carbonate and tetraethylammonium perchlorate (dopant) were stirred with 1: 5: 1: 1: 0.1 for 30 minutes at room temperature and gelled at a temperature of 60 ° C. The composite gel thus produced was pulverized into fine particles having an average particle size of 30 μm. 3 tons using these particles
-Pressing was carried out at a pressure of cm ² , and a tablet having a diameter of 10 mm and a thickness of about 150 μm was produced and used as the electrolyte 5.

Separately from the composite gel, 10 wt% graphite fine particles (average particle size 0.5 μm) based on the sol mixture.
Was added and the mixture was stirred for another 30 minutes, and then gelled at a temperature of 60 ° C. Further, the gel was heated at 110 ° C. to evaporate water. The electrical conductivity of this gel is 9 × 10 ^-4 S at room temperature.
It was cm ^-1 . The gel thus produced was pulverized into fine particles having an average particle size of 30 μm. 5 for the mixture
0 wt% phenolic activated carbon particles (specific surface area: 200
0 m ² g ^-1 , average particle size 20 μm) and 2 wt% as binder
% Fluorine resin is added and stirred, then 100 Kgcm
A positive electrode 1 and a negative electrode 2 of polarizable electrodes were produced by temporary press molding under a pressure of ^-2 .

The positive electrode 1 and the current collector 3 made of a stainless steel mesh, which were tentatively press-molded, or the negative electrode 2 and the current collector 4 were stacked, and the whole was finally pressed at a pressure of 3 ton · cm ⁻² to a thickness of about 500 μm and a diameter of 10 mm The tablets of

By using the tablet-shaped positive electrode 1, negative electrode 2 and electrolyte 5 thus produced, a coin type electric double layer capacitor having the same structure as in Example 1 was produced.

After charging this capacitor at 2.8 V, 10
A constant current discharge was performed at μA to obtain a capacity of 0.1 F and an impedance of 9 ohms. Further, when 2.8 V was constantly applied in the atmosphere of 70 ° C., the capacity reduction rate after 1000 hours was 12% with respect to the initial capacity. In addition, no electrolyte leakage was found in the samples used in the experiment. Even if a system of other possible combinations of an organic solvent such as ethylene carbonate, gamma-butyl lactone, dimethylformamide or dimethylsulfoxide and an electrolyte salt such as tetraethylammonium perchlorate or tetraethylammonium borofluoride is used, It was possible to fabricate a capacitor exhibiting almost the same characteristics as described above. When a conductive resin made of graphite / acrylic resin was used for the current collecting layer, the impedance was as large as 14 ohms, but the reliability was almost the same as that of this example.

Further, even if pitch-based or polyacrylonitrile (PAN) -based activated carbon particles were used in place of the phenol-based activated carbon particles, the same characteristics as the capacitor of this example were shown.

(Example 8) As a starting composition of a composite gel which is an electrolyte, Si (OEt) ₄ , ethanol, and
Water, propylene carbonate and tetraethylammonium perchlorate (dopant) were stirred with 1: 5: 1: 1: 0.1 for 30 minutes at room temperature and gelled at a temperature of 60 ° C. The gel thus produced was crushed to obtain an average particle size of 30
The fine particles were μm. 3 ton · c
Press-formed at a pressure of m ² , diameter 10 mm, thickness about 15
A 0 μm tablet was prepared and used as the electrolyte 5.

Separately from the above composite gel, 49 wt% of the above composite gel and phenol-based activated carbon particles (specific surface area: 2000 m ² g ^-1 , average particle size 20 μm) as a material for the polarizable electrode.
49 wt% and 2 wt% of a fluororesin as a binder were mixed by stirring, 5 wt% of methanol was added to the above mixture, and the mixture was further stirred to form a slurry. This slurry is applied to 0.5 mm-thick mesh aluminum serving as a current collector and dried at 110 ° C. to be held on the current collector, and a disk-shaped positive electrode 1 and negative electrode 2 having a thickness of about 500 μm and a diameter of 10 mm are provided. It was made.

The positive electrode 1 and the negative electrode 2 thus produced,
Using the electrolyte 5, a coin-type electric double layer capacitor having the same structure as in FIG. 1 was produced. This capacitor is 2.8V
After being charged at 10 μA, it was discharged at a constant current with a capacity of 0.07 F and an impedance of 11 ohms. Moreover, when 2.8 V was constantly applied in an atmosphere of 70 ° C., the initial capacity was 10
The capacity reduction rate after 00 hours was 12%. In addition, no electrolyte leakage was found in the samples used in the experiment.

Almost the same reliability as that of this example was shown even if an aluminum etching foil or an expanded metal having an oblique cut was used as the current collector. (Example 9) As a starting composition of a composite gel as a polarizable electrode, Si (OEt) ₄ , ethanol, water, propylene carbonate and tetraethylammonium perchlorate (dopant) were used in a molar ratio of 1: 5: 1: 1 :. Stir for 30 minutes at room temperature using 0.1, and then add 5 to the mixed sol.
0 wt% phenolic activated carbon particles (specific surface area: 200
0 m ² g ^-1 , average particle size 20 μm) was added and stirred for another 30 minutes, and then 0.5 mm thick mesh aluminum serving as a current collector was dipped in the gel to promote gelation at 60 ° C. The composite gel and activated carbon are retained on the current collector by further drying at ℃, and the thickness is about 500 μm and the diameter is 1
The positive electrode 1 and the negative electrode 2 of 0 mm were used.

Separately from the above gel, a sol containing no 50 wt% phenol-based activated carbon particles was prepared and the positive electrode 1,
The electrolyte layer 5 having a thickness of 100 μm was formed by repeating the coating on one surface of the negative electrode 2 and the drying at 60 ° C., and the coating was dried at 110 ° C.

The positive electrode 1 and the negative electrode 2 thus produced,
Using the electrolyte 5, a coin-type electric double layer capacitor having the same structure as in FIG. 1 was produced. This capacitor is 2.8V
The battery was charged at 10 μA and discharged at a constant current of 10 μA to obtain a capacity of 0.09 F and an impedance of 8 ohms. Moreover, when 2.8 V was constantly applied in an atmosphere of 70 ° C., the initial capacity was 100%.
The capacity reduction rate after 0 hour was 12%. In addition, no electrolyte leakage was found in the samples used in the experiment.

Other ethylene carbonate, gamma-
Even if a system of a possible combination of an organic solvent such as butyl lactone, dimethylformamide or dimethylsulfoxide, and an electrolyte salt such as tetraethylammonium perchlorate, tetraethylammonium borofluoride, etc. is used, substantially the same properties as in this example are shown. A capacitor could be manufactured.

Further, even if pitch-based or polyacrylonitrile (PAN) -based activated carbon particles were used in place of the phenol-based activated carbon particles, the same characteristics as those of the capacitor of this embodiment were exhibited.

(Example 10) As a starting composition of a composite gel as a polarizable electrode, Si (OEt) ₄ , ethanol, water, propylene carbonate and tetraethylammonium perchlorate (dopant) were used in a molar ratio of 1: 5: 1. : 1:
The mixture was stirred for 30 minutes at room temperature using 0.1, and further 50 wt% of phenol-based activated carbon particles (specific surface area: 2000 m ² g ^-1 , average particle size 20 μm) were added to the mixed sol.
After adding wt% of graphite fine particles (average particle diameter 0.5 μm) and stirring for 30 minutes, 0.5 mm thick mesh aluminum serving as a current collector was dipped in the gel and gelation was allowed to proceed at 60 ° C. By further drying at 110 ° C,
Hold the composite gel, activated carbon and graphite fine particles on the current collector,
The positive electrode 1 and the negative electrode 2 each having a thickness of about 500 μm and a diameter of 10 mm were used.

Separately from the above gel, a sol to which phenol-based activated carbon particles and graphite fine particles have not been added is applied to one surface of the positive electrode 1 and the negative electrode 2, and drying at 60 ° C. is repeated to obtain a 100 μm thick electrolyte layer. Forming 5 and 110
It was dried at ° C.

The positive electrode 1 and the negative electrode 2 thus produced,
Using the electrolyte 5, a coin-type electric double layer capacitor having the same structure as in FIG. 1 was produced. This capacitor is 2.8V
After being charged at 10 μA, it was discharged at a constant current to obtain a capacity of 0.12 F and an impedance of 7 ohms. Moreover, when 2.8 V was constantly applied in an atmosphere of 70 ° C., the initial capacity was 100%.
The capacity reduction rate after 0 hour was 8%. In addition, no electrolyte leakage was found in the samples used in the experiment.

Other ethylene carbonate, gamma-
Even if a system of a possible combination of an organic solvent such as butyl lactone, dimethylformamide or dimethylsulfoxide, and an electrolyte salt such as tetraethylammonium perchlorate, tetraethylammonium borofluoride, etc. is used, substantially the same properties as in this example are shown. A capacitor could be manufactured.

Further, even if pitch-based or polyacrylonitrile (PAN) -based activated carbon particles were used in place of the phenol-based activated carbon particles, the same characteristics as those of the capacitor of this embodiment were shown.

(Example 11) As the starting composition of the composite gel, Si (OEt) ₄ , ethanol, water, propylene carbonate and tetraethylammonium perchlorate (dopant) were used in a molar ratio of 1: 5: 1: 1: 0. No. 1 and agitated at room temperature for 30 minutes, and a thickness formed on one surface by a thermal spraying method 1
A phenol-based activated carbon fiber cloth (specific surface area: 2000 m ² g ^-1 , unit weight: 120 g · cm ² ) having an aluminum current collector layer of 00 μm is dipped, gelation proceeds at 60 ° C., and further dried at 110 ° C. As a result, the composite gel is retained on the activated carbon fiber cloth and has a thickness of about 800 μm and a diameter of 10
mm of positive electrode and negative electrode. Then, by applying the sol to one surface of the positive electrode and the negative electrode and repeating drying at 60 ° C.,
An electrolyte layer 5 having a thickness of 100 μm was formed and dried at 110 ° C.

The positive electrode 1 and the negative electrode 2 thus produced,
Using the electrolyte 5, a coin-type electric double layer capacitor having the same structure as in FIG. 1 was produced. This capacitor is 2.8V
The battery was charged at 10 μA and discharged at a constant current of 10 μA to obtain a capacity of 0.24 F and an impedance of 20 ohms. Moreover, when 2.8 V was constantly applied in an atmosphere of 70 ° C., the initial capacity was 10
The capacity reduction rate after 00 hours was 8%. In addition, no electrolyte leakage was found in the samples used in the experiment.

Other ethylene carbonate, gamma-
Even if a system of a possible combination of an organic solvent such as butyl lactone, dimethylformamide or dimethylsulfoxide, and an electrolyte salt such as tetraethylammonium perchlorate, tetraethylammonium borofluoride, etc. is used, substantially the same properties as in this example are shown. A capacitor could be manufactured.

Further, even if a pitch-based or polyacrylonitrile (PAN) -based activated carbon fiber cloth was used instead of the phenol-based activated carbon fiber cloth, the same characteristics as those of the capacitor of this example were shown.

(Example 12) As a starting composition of a composite gel, Si (OEt) ₄ , ethanol, water, propylene carbonate and tetraethylammonium perchlorate (dopant) were used in a molar ratio of 1: 5: 1: 1: 0. Stir for 30 minutes at room temperature using 1 and further 10 times to this mixed sol.
Add wt% graphite fine particles (average particle size 0.5 μm) to 3
After stirring for 0 minutes, one side has a thickness of 1 formed by thermal spraying.
A phenol-based activated carbon fiber cloth (specific surface area: 2000 m ² g ^-1 , unit weight: 120 g · cm ² ) having an aluminum current collector layer of 00 μm is dipped, gelation proceeds at 60 ° C., and further dried at 110 ° C. As a result, the composite gel is held on an activated carbon fiber cloth to a thickness of about 800 μm and a diameter of 10 m
m of the positive electrode and the negative electrode.

Separately from the above sol, a sol to which no graphite fine particles are added is applied to one surface of each of the positive electrode 1 and the negative electrode 2, and drying at 60 ° C. is repeated to obtain an electrolyte layer 5 having a thickness of 100 μm.
Was formed and dried at 110 ° C.

The positive electrode 1 and the negative electrode 2 thus produced,
Using the electrolyte 5, a coin-type electric double layer capacitor having the same structure as in FIG. 1 was produced. This capacitor is 2.8V
The battery was charged at 10 μA and discharged at a constant current at a capacity of 0.26 F and an impedance of 16 ohms. Moreover, when 2.8 V was constantly applied in an atmosphere of 70 ° C., the initial capacity was 10
The capacity reduction rate after 00 hours was 4%. In addition, no electrolyte leakage was found in the samples used in the experiment.

Other ethylene carbonate, gamma-
Even if a system of a possible combination of an organic solvent such as butyl lactone, dimethylformamide or dimethylsulfoxide, and an electrolyte salt such as tetraethylammonium perchlorate, tetraethylammonium borofluoride, etc. is used, substantially the same properties as in this example are shown. A capacitor could be manufactured.

Further, even if a pitch-based or polyacrylonitrile (PAN) -based activated carbon fiber cloth was used in place of the phenol-based activated carbon fiber cloth, the same characteristics as those of the capacitor of this example were shown.

[0108]

As described above, in the electric double layer capacitor of the present invention, the polarizable electrode on the positive electrode side and the polarizable electrode on the negative electrode side face each other through the electrolyte using the composite gel composed of the dopant and the matrix gel. Each polarizable electrode is provided with a current collector made of a metal or a conductive resin, and activated carbon is used for the polarizable electrodes on the positive electrode side and the negative electrode side. Since the electric double layer capacity is used, there is no part that deteriorates due to electrochemical reaction, the decomposition voltage is relatively high, and
Since the internal resistance can be reduced and the electrolytic solution is a gel, it is a highly reliable electric double layer capacitor with no leakage.

When the matrix gel is at least one selected from silica gel, alumina gel and titania gel, the chemical stability of the electric double layer capacitor is improved.

Next, in the first production method of the present invention, a mixed sol composed of a dopant and a metal alkoxide is hydrolyzed to prepare a composite gel as an electrolyte, and activated carbon is added to the composite gel prepared from the mixed sol. Mixed to form a polarizable electrode on the positive electrode side and a polarizable electrode on the negative electrode side, a collector made of a metal or a conductive resin is formed on each of the polarizable electrodes, and a component on the positive electrode side is formed through the electrolyte. By providing the polar electrode and the polarizable electrode on the negative electrode side to face each other, a polarizable electrode having a uniform composition can be obtained, and an electric double layer capacitor without leakage of the electrolytic solution can be manufactured.

In the second production method of the present invention, a composite gel as an electrolyte is prepared by hydrolyzing a mixed sol composed of a dopant and a metal alkoxide, and a mixed sol composed of a dopant, a metal alkoxide and activated carbon is hydrolyzed. By decomposing, a polarizable electrode on the positive electrode side and a polarizable electrode on the negative electrode side are formed, and a collector made of a metal or a conductive resin is formed on each of the polarizable electrodes, and the positive electrode side is formed through the electrolyte. By providing the polarizable electrode and the polarizable electrode on the negative electrode side to face each other, a polarizable electrode having a uniform composition can be obtained, and an electric double layer capacitor without leakage of the electrolytic solution can be manufactured.

Further, the third production method of the present invention is to produce a composite gel as an electrolyte by hydrolyzing a mixed sol composed of a dopant and a metal alkoxide, and to the composite gel produced from the mixed sol, activated carbon and a bond are added. A polarizable electrode on the positive electrode side and a polarizable electrode on the negative electrode side are formed by mixing an agent, and each of the polarizable electrodes is press-molded together with a current collector made of a metal or a conductive resin, and the positive electrode is interposed via the electrolyte. By providing the polarizable electrode on one side and the polarizable electrode on the negative side so as to face each other, a polarizable electrode having a uniform composition can be obtained, and an electric double layer capacitor without leakage of the electrolytic solution can be easily manufactured.

In the first, second or third production method, the mixed sol is further mixed with at least one organic solvent selected from ethylene carbonate, propylene carbonate, gamma-butyl lactone, dimethylformamide, and dimethylsulfoxide. It is convenient to add the above because these organic solvents have a high boiling point of 200 ° C. or higher and are chemically stable.

Further, the fourth production method of the present invention is to prepare a composite gel as an electrolyte by hydrolyzing a mixed sol composed of a dopant, a metal alkoxide and an organic solvent, and prepare a composite gel prepared from the mixed sol, After mixing activated carbon and a binder, the mixture is applied to a metal current collector to form a polarizable electrode on the positive electrode side and a polarizable electrode on the negative electrode side, and the polarizable electrode on the positive electrode side and the negative electrode side are separated via the electrolyte. By providing the polar electrodes facing each other, the mixture of the composite gel, the activated carbon and the binder can be held on the metal current collector, so that the positive electrode and the negative electrode having a uniform composition can be obtained, and the internal resistance excellent in the current collecting ability can be obtained. A small and highly reliable electric double layer capacitor can be manufactured.

Further, the fifth production method of the present invention is that a polarizable electrode on the positive electrode side is obtained by immersing a metal current collector in a mixed sol composed of a dopant, a metal alkoxide, an organic solvent and activated carbon to hydrolyze the sol. And a polarizable electrode on the negative electrode side is formed, and a mixed sol consisting of a dopant, a metal alkoxide and an organic solvent is applied to each of the polarizable electrodes and hydrolyzed to produce a composite gel as an electrolyte, which is then passed through the electrolyte. By providing the polarizable electrode on the positive electrode side and the polarizable electrode on the negative electrode side by side so that the composite sol can be held on the metal current collector, a positive electrode and a negative electrode having a uniform composition can be obtained, A highly reliable electric double layer capacitor with excellent internal resistance can be manufactured.

Further, in the sixth production method of the present invention, after forming a metal current collector layer on the activated carbon fiber cloth, the activated carbon fiber cloth is dipped in a mixed sol composed of a dopant, a metal alkoxide and an organic solvent for hydrolysis. To form a polarizable electrode on the positive electrode side and a polarizable electrode on the negative electrode side by applying the mixed sol to each of the polarizable electrodes and hydrolyzing to produce a composite gel as an electrolyte, Since the polarizable electrode on the positive electrode side and the polarizable electrode on the negative electrode side are provided to face each other through the composite gel can be held on the metal current collector, a positive electrode and a negative electrode having a uniform composition can be obtained. It is possible to manufacture a highly reliable electric double layer capacitor having excellent electric power and small internal resistance.

In the first to sixth manufacturing methods, when graphite fine particles are further mixed with the mixed sol used for the polarizable electrode, the electrical resistance of the polarizable electrode can be reduced by adding the graphite fine particles. A small and highly reliable electric double layer capacitor can be manufactured.

In the electric double layer capacitor or the first to sixth manufacturing methods thereof according to the present invention, the dopant is hydrochloric acid, sulfuric acid, heteropolyacid, perchloric acid, potassium hydroxide acid or alkali, or tetraethylammonium perchlorate. , And at least one selected from tetraethylammonium borofluoride, the electric conductivity can be increased in an acid or alkaline solution, the internal resistance of the capacitor can be reduced, and tetraethylammonium perchlorate or tetraethylammonium borofluoride can be reduced. The organic electrolytic solution using the electrolyte salt as described above has a high decomposition voltage and can increase the withstand voltage of the capacitor.

Further, in the electric double layer capacitor of the present invention or the first to sixth manufacturing methods thereof, the activated carbon is phenol-based, pitch-based or polyacrylonitrile (PA
N) is at least one selected from powdery or fibrous activated carbons, the activated carbons can have a specific surface area of 2000 m ² g ^-1, which is more than twice that of palm shell coal,
Further, the pore size can be controlled within the range of 2 to 4 nm, and the double layer capacity can be increased.

Further, in the electric double layer capacitor of the present invention or the first to sixth manufacturing methods thereof, if the metal used for the current collector is at least one selected from aluminum, titanium and stainless steel, the polarizable electrode is used. In particular, the electrochemical stability of the positive electrode is improved.

In the fourth to sixth production methods of the present invention, the organic solvent is at least one selected from ethylene carbonate, propylene carbonate, gamma-butyl lactone, dimethylformamide and dimethyl sulfoxide. The organic solvent has a boiling point of 200
It is convenient because it is chemically stable above ℃.

The composite gel of the present invention can be applied not only as an electrolyte for electric double layer capacitors but also as an electrolyte for batteries and electrochromic devices.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of an electric double layer capacitor of one embodiment of the present invention.

[Explanation of symbols]

 1 Positive Electrode 2 Negative Electrode 3 Current Collector 4 Current Collector 5 Electrolyte 6 Upper Member (Sealing Plate) 7 Lower Member (Case) 8 Packing

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location H01G 9/025 9375-5E H01G 9/00 301 A 9375-5E 301 G (72) Inventor Tsutomu Minami 1-1 Gakuencho, Sakai City, Osaka Prefecture, Osaka Prefectural University

Claims (14)

[Claims] 1. A polarizable electrode on the positive electrode side and a polarizable electrode on the negative electrode side are opposed to each other via an electrolyte using a composite gel composed of a dopant and a matrix gel, and each polarizable electrode is made of a metal or a conductive resin. An electric double layer capacitor comprising a current collector and using activated carbon for the polarizable electrodes on the positive electrode side and the negative electrode side. 2. The electric double layer capacitor according to claim 1, wherein the matrix gel is at least one selected from silica gel, alumina gel, and titania gel. 3. A composite gel as an electrolyte is prepared by hydrolyzing a mixed sol composed of a dopant and a metal alkoxide, and activated carbon is mixed with the composite gel prepared from the mixed sol to prepare a polarizable electrode on the positive electrode side and a negative electrode side. Polarizable electrodes are formed, a collector made of a metal or a conductive resin is formed on each of the polarizable electrodes, and the polarizable electrode on the positive electrode side and the polarizable electrode on the negative electrode side are opposed to each other through the electrolyte. A method of manufacturing an electric double-layer capacitor provided facing each other. 4. A composite gel as an electrolyte is prepared by hydrolyzing a mixed sol composed of a dopant and a metal alkoxide, and a polarizable electrode on the positive electrode side is prepared by hydrolyzing a mixed sol composed of a dopant, a metal alkoxide and activated carbon. And a polarizable electrode on the negative electrode side, and a collector made of a metal or a conductive resin is formed on each of the polarizable electrodes, and the polarizable electrode on the positive electrode side and the polarizable electrode on the negative electrode side are formed through the electrolyte. A method for manufacturing an electric double layer capacitor, in which electrodes are provided facing each other. 5. A composite gel as an electrolyte is prepared by hydrolyzing a mixed sol composed of a dopant and a metal alkoxide, and activated carbon and a binder are mixed with the composite gel prepared from the mixed sol to prepare a polarizable electrode on the positive electrode side. And a polarizable electrode on the negative electrode side are formed, and each of the polarizable electrodes is press-molded together with a collector made of a metal or a conductive resin, and the polarizable electrode on the positive electrode side and the negative electrode side are separated via the electrolyte. A method for manufacturing an electric double layer capacitor, which comprises polar electrodes facing each other. 6. The mixed solvent according to claim 3, 4 or 5, wherein at least one organic solvent selected from ethylene carbonate, propylene carbonate, gamma-butyl lactone, dimethylformamide, and dimethylsulfoxide is further added to the mixed sol. Of manufacturing electric double layer capacitor of. 7. A composite gel as an electrolyte is prepared by hydrolyzing a mixed sol composed of a dopant, a metal alkoxide and an organic solvent, and the composite gel prepared from the mixed sol, activated carbon and a binder are mixed, and then a metal is prepared. It is applied to a current collector to form a polarizable electrode on the positive electrode side and a polarizable electrode on the negative electrode side, and the polarizable electrode on the positive electrode side and the polarizable electrode on the negative electrode side are provided to face each other through the electrolyte. Method of manufacturing multilayer capacitor. 8. A polarizable electrode on the positive electrode side and a polarizable electrode on the negative electrode side are formed by immersing a metal current collector in a mixed sol composed of a dopant, a metal alkoxide, an organic solvent and activated carbon to hydrolyze the sol. A composite gel as an electrolyte is produced by applying a mixed sol consisting of a dopant, a metal alkoxide, and an organic solvent to each of the polarizable electrodes and hydrolyzing them, and the polarizable electrode on the positive electrode side and the negative electrode via the electrolyte. A method of manufacturing an electric double layer capacitor, in which polarizable electrodes on one side are opposed to each other. 9. A polarizable electrode on the positive electrode side is formed by forming a metal current collector layer on an activated carbon fiber cloth and then immersing the activated carbon fiber cloth in a mixed sol composed of a dopant, a metal alkoxide and an organic solvent to cause hydrolysis. A polarizable electrode on the negative electrode side is formed, and a mixed gel as an electrolyte is produced by applying the mixed sol to each of the polarizable electrodes and hydrolyzing it, and a polarizable electrode on the positive electrode side is formed through the electrolyte. A method for manufacturing an electric double layer capacitor, in which polarizable electrodes on the negative electrode side are provided so as to face each other. 10. The method for producing an electric double layer capacitor according to claim 3, wherein graphite fine particles are further mixed with the mixed sol used for the polarizable electrode. 11. The method according to claim 1, wherein the dopant is at least one selected from hydrochloric acid, sulfuric acid, heteropolyacid, perchloric acid, potassium hydroxide acid or alkali, tetraethylammonium perchlorate, and tetraethylammonium borofluoride. 10. The method for manufacturing the electric double layer capacitor according to claim 3 or the electric double layer capacitor according to claim 3, 4, 5, 7, 8 or 9. 12. The electric double layer capacitor or claim 3 according to claim 1, wherein the activated carbon is at least one selected from a phenol-based, pitch-based, and polyacrylonitrile (PAN) -based powdered or fibrous activated carbon. ,
4. The method for manufacturing the electric double layer capacitor according to 4, 5, 7, 8 or 9. 13. The metal used for the current collector is aluminum,
It is at least 1 sort (s) chosen from titanium and stainless steel, The manufacturing method of the electric double layer capacitor of Claim 1 or the electric double layer capacitor of Claim 3, 4, 5, 7, 8 or 9. 14. The electric double layer capacitor according to claim 7, 8 or 9, wherein the organic solvent is at least one selected from ethylene carbonate, propylene carbonate, gamma-butyl lactone, dimethylformamide, and dimethylsulfoxide. Manufacturing method.