JPH0883738A - Electric double-layer capacitor - Google Patents

Abstract

PURPOSE: To markedly lessen an electric double-layer capacitor in inner resistance by a method wherein it is equipped with a pair of polarizable positive/ negative electrodes provided onto the same plane apart from each other by a certain distance on an insulating support, collectors of the polarizable electrodes, and electrolyte. CONSTITUTION: Gold electrodes are formed as a pair of positive/negative collectors 2 and 3 on an insulating support 1 through such a manner that gold paste is screen-printed, dried up, and burned into the gold electrodes. Polarizable electrodes 4 and 5 are formed on the pair of positive/negative collectors 2 and 3 through a screen printing method, and leads 6 and 7 of platinum foil are fixed to the polarizable electrodes 4 and 5. After the leads 6 and 7 are fixed to the polarizable electrodes 4 and 5, the polarizable electrodes 4 and 5 are impregnated with sulfuric acid as electrolyte. Then, the periphery of a capacitor element is covered with sealing materials 9 and 10, and the sealing materials 9 and 10 are fused together for the formation of a capacitor. By this setup, a capacitor is capable of being markedly reduced in inner resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric double layer capacitor for accumulating charges in an electric double layer generated at the interface between a polarizable electrode and an electrolytic solution.

[0002]

2. Description of the Related Art Conventional electric double layer capacitors are classified into two types according to their configurations. The details will be described below with reference to the drawings. FIG. 7 shows an electric double layer capacitor which is commonly called a wound type. Collector 31 made of aluminum foil,
Polarizable electrodes 32, 34 composed of activated carbon and a binder on 33
Is formed, and these polarizable electrodes are spirally wound through a separator 35 made of glass-mixed paper and then inserted into an aluminum container 36, and an organic electrolysis consisting of a propylene carbonate solution in which tetraethylammonium perchlorate is dissolved is formed. After injecting the liquid, the opening of the container 36 is sealed with a sealing rubber plug 37. The sealing rubber 37 has leads 38, 3 of the polarizable electrodes 32, 34.
9 is attached liquid-tightly and airtightly. On the other hand, FIG.
Shows an electric double layer capacitor commonly called a paste type. Paste-like polarizable electrode 5 consisting of activated carbon and dilute sulfuric acid
1, 52 and a separator 53 made of a polypropylene porous body interposed therebetween are filled in containers 54, 55 made of a current collector made of conductive rubber, and insulation is provided between the peripheral portions of the containers 54, 55. Sealing material 5 made of natural rubber
6 is inserted, and the sealing material, the container and the separator are heat-sealed and sealed.

[0003]

The above-mentioned conventional electric double layer capacitors all require a separator as a constituent member, and a resistance component is generated when the electrolytic solution passes through the separator during charging / discharging, and the internal resistance of the capacitor increases. It had the problem of becoming expensive.

[0004]

The electric double layer capacitor of the present invention comprises a pair of positive and negative polarizable electrodes provided on the same surface of an insulating support and spaced apart from each other, and a collection of the polarizable electrodes. It is composed of an electric body and an electrolytic solution. Moreover, it has a structure in which the insulating support is wound. Furthermore, the present invention is provided with a laminated body in which a plurality of insulative supports having a pair of positive and negative polarizable electrodes provided on the same surface and a collector of the polarizable electrodes are laminated, and an electrolytic solution. As the electrolytic solution, either an organic electrolytic solution or an aqueous electrolytic solution can be applied.

[0005]

The electric double layer capacitor according to the present invention is composed of a pair of positive and negative polarizable electrodes provided on the same surface of the insulating support as described above, a collector of each polarizable electrode, and an electrolytic solution. There is no separator. Therefore, no resistance component is generated when the electrolyte passes through the separator during charging and discharging.
Therefore, the internal resistance can be significantly reduced as compared with the conventional electric double layer capacitor.

[0006]

The present invention will be described below with reference to its examples. Example 1 A gold electrode is formed as a pair of positive and negative current collectors 2 and 3 on an insulating support 1 made of an alumina substrate by screen printing a gold paste, drying and firing.
As a paste for producing a polarizable electrode, a phenol-based activated carbon powder having a particle size of 5 μm and a phenol resin as a binder were mixed in a weight ratio of 7: 3, and this mixture was mixed with a dispersion medium of 2-methoxyethanol in an equal weight ratio. To prepare a paste. The paste is screen-printed on the current collectors 2 and 3 to form polarizable electrodes 4 and 5. The polarizable electrodes 4 and 5 each have a size of 10 mm × 20 mm and a thickness of 35.
It is 0 μm, and the distance between the electrodes 4 and 5 is 1 mm. Next, the leads 6 and 7 made of platinum foil are attached to the polarizable electrodes 4 and 5. To attach the lead, first, the polarizable electrode at the lead attachment position is scraped off by a width of about 1 mm to expose the current collector, and the platinum foil is fixed thereto by the pin 8 made of platinum.
After attaching the leads 6 and 7 to the polarized electrodes 4 and 5 as described above, the polarizable electrodes 4 and 5 are impregnated with a 30 wt% sulfuric acid aqueous solution as an electrolytic solution. Next, the periphery is covered with a sealing material 9 made of butyl rubber, and both are heat-sealed to complete a capacitor.

[Embodiment 2] Gold electrodes are formed as a pair of positive and negative current collectors 12 and 13 by thermal spraying on an insulating support 11 made of a polyethylene sheet having a roughened surface. On the other hand, as a polarizable electrode manufacturing paste, the particle size is 5μ
m of petroleum pitch-based activated carbon powder and a phenol resin of a binder are mixed in a weight ratio of 7: 3, and this mixture is dispersed in a dispersion medium 2-methoxyethanol in an equal weight ratio to prepare a paste. This paste is used for the current collectors 12 and 1
The polarizable electrodes 14 and 15 are formed by screen-printing on the electrode 3. The polarizable electrodes 14 and 15 each have a size of 10 mm ×
The thickness is 70 mm, the thickness is 100 μm, and the distance between the electrodes 14 and 15 is 1 mm. Next, leads 16 and 17 made of platinum foil are attached to the polarizable electrodes 14 and 15. As in the case of the first embodiment, the lead is attached by scraping the polarizable electrode at the lead attaching position by a width of about 1 mm to expose the current collector, and fixing the platinum foil thereto with the platinum pin 18. Since the polarized electrode is long, it is preferable to attach a plurality of leads. In this example, 6 leads were attached to each electrode. Next, the insulating support 11 is spirally wound with the polarizable electrode surface inside, and then inserted into a polyethylene case 19 to provide 30% by weight as an electrolytic solution.
After injecting the sulfuric acid of, the lid 20 also made of polyethylene is sealed to complete the electric double layer capacitor. It should be noted that the plurality of leads 16 and 17 of each polarization electrode are combined into one and led out to the outside of the case.

[Embodiment 3] Gold electrodes are formed by electroless plating as a pair of positive and negative current collectors 22 and 23 on an insulating support 21 made of a polyethylene sheet having a roughened surface. On the other hand, as a polarizable electrode production paste,
A coconut shell activated carbon powder having a particle size of 5 μm and a fluororesin as a binder are mixed in a weight ratio of 7: 3, and the mixture is dispersed in a dispersion medium 2-methoxyethanol in an equal weight ratio to prepare a paste. To do. This paste is used for the current collector 22,
The polarizable electrodes 24 and 25 are formed by screen printing on 23. The polarizable electrodes 24 and 25 each have a size of 10 mm
× 10 mm, thickness 350 μm, electrodes 24 and 25
The distance between and is 1 mm. Next, the polarizable electrodes 24, 25
Leads 26 and 27 made of platinum foil are attached to. As in the case of the first embodiment, the lead is attached by scraping off the polarizable electrode at the lead attaching position by a width of about 1 mm to expose the current collector, and fixing the platinum foil thereto with the platinum pin 28. Seven insulative supports 21 provided with the current collectors 22, 23, the polarizable electrodes 24, 25 and the leads 26, 27 as described above were prepared and laminated in the same direction,
The polarizable electrode is impregnated with a 30 wt% sulfuric acid aqueous solution as an electrolytic solution, and then the periphery is molded with a polyethylene resin 29 to complete an electric double layer capacitor.

The internal resistance of the electric double layer capacitor according to the above embodiment is shown in Table 1 together with the value of the electric double layer capacitor according to the conventional example. The specifications of the electric double layer capacitor are unified to 5.5V-1F.

[0010]

[Table 1]

[0011]

As is apparent from the above, according to the present invention, an electric double layer capacitor having a low internal resistance can be realized.

[Brief description of drawings]

FIG. 1 is a fragmentary front view of an electric double layer capacitor according to an embodiment of the present invention.

FIG. 2 is a plan view of a support body having polarizable electrodes of the same capacitor.

FIG. 3 is a fragmentary front view of an electric double layer capacitor according to another embodiment of the present invention.

FIG. 4 is a plan view of a support body having polarizable electrodes of the same capacitor.

FIG. 5 is a fragmentary front view of an electric double layer capacitor according to still another embodiment of the present invention.

FIG. 6 is a plan view of a support body having polarizable electrodes of the same capacitor.

FIG. 7 is a fragmentary front view of an electric double layer capacitor according to a conventional example.

FIG. 8 is a vertical cross-sectional view of an electric double layer capacitor according to another conventional example.

[Explanation of symbols]

 1, 11, 21 Insulating support 2, 12, 22 Current collector 3, 13, 23 Current collector 4, 14, 24 Polarizing electrode 5, 15, 25 Polarizing electrode 6, 16, 26 Lead 7, 17 , 27 Leads 9, 10 Sealing material 19 Case 20 Lid 29 Mold resin

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akihiko Yoshida 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (3)

[Claims] 1. An electric double layer capacitor comprising a pair of positive and negative polarizable electrodes provided on the same surface of an insulating support and spaced apart from each other, a collector of each polarizable electrode, and an electrolytic solution. . 2. An insulating support comprising a pair of positive and negative polarizable electrodes provided on the same surface of the insulative support and spaced apart from each other, a collector of each of the polarizable electrodes, and an electrolytic solution. An electric double layer capacitor having a structure in which a support is wound. 3. An electric double layer capacitor comprising a plurality of laminates of insulating supports provided with a pair of positive and negative polarizable electrodes on the same surface and a collector of the polarizable electrodes, and an electrolytic solution. .