JPH0394412A - Electric double layer capacitor - Google Patents

Abstract

PURPOSE:To realize a thin shape and to execute continuous production operation by a method wherein a sheet for separator use is bent and folded alternately in a mountain fold manner and a valley fold manner and a collector and a polarizing electrode are faced so as to be into close contact. CONSTITUTION:A semiconductor film is used for a sheet 30 for separator use; thin films for collectors 1 and polarizing electrodes 2 are formed in a pattern of the same size and alternately so as to be adjacent in a face direction. Formation positions of the individual thin films are selected in positions where the thin films for the collectors 1 and the thin films for the polarizing electrodes 2 are faced so as to come into close contact when the sheet 30 for separator use is bent and folded alternately at a boundary crease 5 in a mountain fold manner and a valley fold manner. That is to say, the thin films for the collectors 1 formed at end parts of a separator 3 are bent so as to face the adjacent polarizing electrodes 2; after that, the films are bent by changing bend directions alternately. Thereby, a thin shape is realized and a continuous production operation can be executed.

Description

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

The present invention relates to an electric double layer capacitor that is lightweight and thin.

[Conventional technology]

Figure 6 shows a conventional electric double layer capacitor. In Fig. 6, 1 is a current collector, 2 is a polarizable electrode, 3 is a separator, and 4 is a gasket. As the current collector l, conductive rubber is used. The polarizable electrode 2 is made by mixing activated carbon powder with an electrolytic liquid (eg, dilute sulfuric acid) to form a paste. The gasket 4 is for insulating the polarizable electrode 2 from the surroundings, and is made of insulating rubber. The separator 3 is for preventing conduction between the two polarizable electrodes 2. However, since it is necessary for ions to pass through, 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. Such materials include, for example, porous plastic films (polypropylene). In an electric double layer capacitor having such a configuration, there is a contact resistance between the activated carbon powders contained in the polarizable electrode 2 and a contact resistance between the activated carbon powder and the current collector 1, and these represent the internal resistance of the capacitor. ．． When using an electric double layer capacitor, it is desirable that the internal resistance is low, so pressure is applied from above the current collector 1 to improve contact and reduce the contact resistance. Furthermore, the withstand voltage of the single electric double layer capacitor shown in Figure 6 is approximately 1.2V, so depending on the application, several of these may be stacked together.

[Problem B that the invention attempts to solve]

As devices become smaller and lighter, electric double layer capacitors built into them become smaller. Lighter weight is required. but,
Conventional electric double layer capacitors use conductive rubber for the current collector or are filled with paste-like polarizable electrodes, so there are limits to how much they can be made smaller and lighter. The problem was that it was not possible. The present invention aims to solve these problems.

[Means to solve the problem]

In order to solve the above problems, the electric double layer capacitor of the present invention includes thin film-like current collectors and polarizable electrodes that are alternately formed adjacent to each other in the surface direction on the surface of a separator sheet, and Fold the sheet into a mountain. The structure was such that the current collector and the polarizable electrode were closely opposed to each other by alternately folding them in valley folds.

[Function] Since the current collector and polarizable electrode are made into thin films, the thickness of the electric double layer capacitor can be made extremely thin. Furthermore, since the current collector and the polarizable electrode are formed on a flat separator sheet using a thin film technique such as printing, it is possible to manufacture the separator continuously.

【Example】

Hereinafter, embodiments of the present invention will be described in detail based on the drawings. Figure 1 shows a developed view of the electric double layer capacitor of the present invention, and Figure 2 shows how to fold it. In these figures, the numbers correspond to those in Figure 6. Further, 5 is a fold line, 30 is a separator sheet, and 1-1 is a terminal portion integrated with the current collector I. In the present invention, a semiconductor film (eg, a polypropylene film) is used as the separator sheet 30. Then, on the surface of this separator sheet 30, thin films of current collectors 1 and polarizable electrodes 2 are alternately formed adjacent to each other in the surface direction in patterns of the same size. When forming these films, known thin film forming techniques such as printing or pasting can be used. For example, a conductive film is used as the current collector 1, and a film of activated carbon impregnated with an electrolyte solution (e.g., dilute sulfuric acid) is used as the polarizable electrode 2, and these are combined into a separator sheet. Paste alternately in the surface direction on the surface of 30. The forming position of each thin film is determined by mountain-folding the separator sheet 30 at the crease 5 made at the border of the thin film. The edges of the separator sheet 30 are selected so that the thin film of the current collector l and the thin film of the polarizable electrode 2 closely face each other when folded alternately in a valley fold. , a thin film of current collector l is formed on only one side. In areas other than the ends, both the current collector 1 and the polarizable electrode 2 are placed on both sides of the separator sheet 30. As shown in FIG. 2, first, the thin film of the current collector l formed at the end of the separator 3 is
Fold it so that it faces you. After that, bend the paper by alternating the bending directions. Figures 3 and 4 are folded and laminated views of the electric double layer capacitor of the present invention. The symbols correspond to those in Figure 1. Fig. 3 shows a cross section of the folded and laminated product cut in the X direction shown in Fig. 1, and Fig. 4 shows a cross section cut in the Y direction and passing through the terminal section 1-1. A cross section is shown. As you can see from these figures, the order of the layers when folded is as follows, starting from the top. "
Separator sheet 30 → Current collector 1 → Polarizable electrode 2 → Separator sheet 30 → Polarizable electrode 2 → Current collector 1 → Separator sheet 30 → Current collector 1 → ...・→Polarizable electrode 2→Separator sheet 30→Polarizable electrode 2→Current collector 1→Separator sheet 30" In this stack, "Current collector 1→Polarizable electrode 2→Separator sheet 30→ One electric double layer capacitor is made up of a set of continuous layers such as "polarizable electrode 2 → current collector 1".
Therefore, only the portion of the separator sheet 30 on which the thin film of the polarizable electrode 2 is formed on both sides is used as the separator 3 of the electric double layer capacitor. By appropriately connecting the above pairs in series or in parallel, an electric double layer capacitor with a desired withstand voltage and a desired capacity can be obtained. Since the current collector I and the polarizable electrode 2 are made of light thin films,
The overall shape is also thin and lightweight. FIG. 5 shows an example of the appearance of the electric double layer capacitor of the present invention. 6 is an outer box containing a folded electric double layer capacitor, and 7 is a terminal. The terminal portion 1-1 shown in FIG. 4 is directly attached to the terminal 7. They are appropriately grouped and connected according to the parallel connection.

【Effect of the invention】

According to the present invention as described above, the following effects are achieved. ■ Electric double layer capacitors can be made thinner because the current collector and polarizable electrodes are made into thin films. In addition, the weight will also be reduced accordingly. ■ The current collector and polarizable electrodes are formed on a flat separator sheet using thin film technology such as printing, so they can be manufactured continuously and are suitable for mass production.

[Brief explanation of drawings]

Figure 1: A developed view of the electric double layer capacitor of the present invention Figure 2: A diagram showing how to fold the electric double layer capacitor of the present invention Figures 3 and 4: An exploded view of the electric double layer capacitor of the present invention Figure 5: Folded laminated diagram of a multilayer capacitor...Example of external appearance of the electric double layer capacitor of the present inventionFigure 6: In the diagram of a conventional electric double layer capacitor, 1
1-1 is a current collector, 1-1 is a terminal part, 2 is a polarizable electrode, 3 is a separator, 4 is a gasket 7, 5 is a fold line, 6 is an outer box, 7 is a terminal, 30 is a separate overnight sheet It is.

Claims (1)

[Claims] Thin film current collectors and polarizable electrodes are alternately formed adjacent to each other in the surface direction on the surface of a separator sheet, and the separator sheet is alternately folded in a mountain fold and a valley fold to collect the current. An electric double layer capacitor characterized in that a body and the polarizable electrode are closely opposed to each other.