JPH0394410A - Electric double layer capacitor - Google Patents

Abstract

PURPOSE:To enhance a pressurization efficiency by a method wherein a gasket is formed by a hardening and molding operation so as to be thinner than a thickness of a polarizing electrode which has been filled with a liquid gasket material of a room-temperature hardening type. CONSTITUTION:A recessed part 8 surrounded by a liquid gasket material 60 with which a collector 1 has been coated is filled with a paste-like polarizing electrode 4. Then, a separator 3 is placed on the filled polarizing electrode 4. While the separator is pressed by using rollers 9 and is being degassed, the separator 3 is bonded. Since the liquid gasket material 60 is compressed and molded at this time, the liquid gasket material 60 of a room-temperature hardening type is compressed and hardened to form a gasket 6. A distance in an up-and-down direction between collectors 1, 2 at parts of gaskets 6, 7 is smaller than that in other parts 6, 7. Thereby, when an electric double layer capacitor is pressurized during its use, a pressurization force is used exclusively to compress polarizing electrodes 4, 5 and an efficient pressurization operation can be executed.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an electric double layer capacitor that can effectively pressurize polarizable electrodes.

[Conventional technology 1] Figure 6 shows a conventional electric double layer capacitor. In Fig. 6, 1.2 is a current collector, 3 is a separator, 4.5 is a polarizable electrode, and 12.13 is a gasket. As the current collectors 1 and 2, conductive rubber is used. The polarizable electrode 4.5 is made by mixing activated carbon powder with an electrolyte solution (eg, dilute sulfuric acid) to form a paste. The gaskets 12 and 13 are for insulating the polarizable electrodes 4 and 5 from the surroundings, and are made of insulating rubber. The separator 3 is for preventing conduction between the polarizable electrodes 4.5. However, since it is necessary to transmit ions,
A porous material is used that has pores that do not allow the activated carbon powder of the polarizable electrode to pass through, but allow ions to pass through. For example, a porous plastic film (polypropylene) is used. In an electric double layer capacitor with such a structure, there is a contact resistance between the activated carbon powder contained in the polarizable electrode 4.5 and a contact resistance between the activated carbon powder and the current collector 1.2, and these exhibit internal resistance. ing. When using a gas double layer capacitor, it is desirable that the internal resistance is low, so it is possible to apply pressure from above the current collector 1.2 to improve contact and reduce the contact resistance. be exposed. The present invention aims to solve these problems. Problems to be Solved by the Invention (Problems) However, the conventional electric double layer capacitor described above has a problem in that the pressurizing force is not effectively utilized. (Explanation of the problem) In order to apply pressure from above the current collector 1.2 to reduce the contact resistance mentioned above, the polarizable electrode 4.5 must be compressed. 12.13 must also be compressed at the same time. However, gasket 12
．． If you try to compress 13, you will receive a large reaction force, so
A large amount of pressure is required. Therefore, a considerable portion of the applied pressure is spent compressing the gaskets 12, 13, and less is used to compress the essential polarizable electrodes 4, 5. In other words, pressurization was not performed efficiently.

[Means to solve the problem]

In order to solve the above problem, in the electric double layer capacitor of the present invention, a room temperature curing liquid gasket material is hardened and molded to be made thinner than the thickness of the filled polarizable electrode to form a gasket.

[Effect 1] When the gasket is shaped as described above, the distance between the upper and lower parts of the upper and lower current collector parts that are glued to the gasket is equal to the distance between the upper and lower parts of the part that is in contact with the polarizable electrode. It becomes smaller. Therefore, when pressurizing an electric double layer capacitor, most of the pressurizing force is used to compress the polarizable electrode, and very little is used to compress the gasket. Therefore, pressurization is performed efficiently. [Embodiments] Hereinafter, embodiments of the present invention will be described in detail based on the drawings. FIG. 1 shows an electric double layer capacitor according to an embodiment of the present invention. The symbols correspond to those in FIG. and,
6.7 is a gasket. The difference in structure from conventional examples is that instead of using solid insulating rubber as the gas get from the beginning, we used a room temperature liquid gasket material that is initially liquid but then hardens at room temperature. It is a point. FIG. 2 shows the state in which the liquid gasket material is applied to the periphery of the current collector, and FIGS. 3 and 4 show the manufacturing process of the electric double layer capacitor of the present invention. The method of manufacturing the electric double layer capacitor of the present invention will be explained below with reference to these figures. ■ First, as shown in Figure 2, the current collector l
Apply liquid gasket material 604 to. A recess 8 is formed surrounded by the liquid gasket material 60. The recess 8 is filled with a paste-like polarizable electrode 4. (2) Next, as shown in FIG. 3, the separator 3 is placed on top of the filled polarizable electrode 4, and the separator 3 is adhered while being pressed with a roller 9 to deaerate (remove air). At this time, the liquid gasket material 60 is compressed and shaped. Since the liquid gasket material 60 is a room temperature curing type, it hardens in a compressed form to form the gasket 6. (2) Apply a liquid gasket material 70 to the peripheral area of the separator 3, and fill the polarizable electrode 5 into the recess formed by the liquid gasket material 70. And, as shown in Figure 4,
The current collector 2 is placed on top of it, and the current collector 2 is adhered after degassing with the roller 9. The liquid gasket material 70 also hardens in a compressed form to become the gasket 7. Since it is manufactured as described above, the distance between the current collectors 1.2 in the vertical direction is smaller in the gasket 6.7 part than in other parts, as shown in FIG. 4 or FIG. Become. That is, among the parts of the current collectors 1 and 2, the gasket 6,
The part that is glued to 7 sinks more than the other parts. Therefore, when applying pressure when using an electric double layer capacitor, no reaction force is received from the sunken gasket 6.7, so the applied force is used exclusively to compress the polarizable electrode 4.5. Therefore, efficient pressurization can be performed. Note that by repeating the steps shown in Figures 3 and 4 one after another, a laminated electric double layer capacitor can be obtained. Now, as mentioned above, pressurization is performed to reduce contact resistance, but in addition to improving the gasket,
By changing the materials used for , 2, the contact resistance can be further reduced. The material for the current collector 1.2 in the above example is as follows:
As in the past, conductive rubber was used, but when carbon fiber paper was used instead, the interaction between the current collector and the polarizable electrode (more precisely, the activated carbon powder contained therein) was improved. Contact resistance can be further reduced. Figure 5 shows the state of contact with activated carbon powder when carbon fiber paper is used as the current collector material. In FIG. 5, IO is carbon fiber paper, 10-1 is whisker-like fiber,
l1 is activated carbon powder contained in the polarizable electrode. Numerous whisker-like fibers 10-1 come out from the surface of the carbon fiber paper 10. Therefore, carbon fiber paper 10
When brought into contact with the polarizable electrode 4 (5), each whisker-like fiber 10-1 comes into contact with a large number of activated carbon powders 11. This is nothing but an increase in the contact area between the current collector and the polarizable electrode. As the contact area increases, the contact resistance decreases. In addition, if there is a risk that the electrolytic liquid (e.g. dilute sulfuric acid) impregnated into the polarizable electrode may seep out from the carbon fiber paper, apply it to the side of the carbon fiber paper that does not come into contact with the polarizable electrode. All you need to do is coat it with conductive resin.

【Effect of the invention】

As described above, according to the electric double layer capacitor of the present invention, the gasket is shaped to be thinner than the thickness of the filled polarizable electrodes, so when applying pressure to reduce contact resistance, the pressure Most of this is used to compress the polarizable electrode and not the gasket. Therefore, pressurization can now be performed efficiently.

[Brief explanation of drawings]

Fig. 1: Electric double layer capacitor according to an embodiment of the present invention Fig. 2: A diagram showing a state in which liquid gasket material is applied to the periphery of the current collector Figs. 3 and 4... Figure 5 shows the manufacturing process of the electric double layer capacitor of the present invention. Figure 6 shows the state of contact with activated carbon powder when carbon fiber paper is used as the current collector material. In the electric double layer capacitor diagram,
1 and 2 are current collectors, 3 is a separator, 4 and 5 are polarizable electrodes, 6 and 7 are gaskets, 8 is a recess, 9 is a roller, 10
The carbon fiber paper l1 is activated carbon powder, 12.13 is a gasket, and 60 and 70 are liquid gasket materials.

Claims (1)

[Claims] An electric double layer capacitor characterized in that a gasket is made by curing and molding a liquid gasket material that hardens at room temperature so that it is thinner than the thickness of the polarizable electrodes filled therein.