JPH0731535Y2 - Electric double layer capacitor sealing structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Industrial Application Field >> The present invention relates to an electric double layer capacitor, and more particularly to a sealing structure thereof.

<< Prior Art >> An electric double layer capacitor has been conventionally used in FIG.
As shown in (b), a polarizable electrode 2 divided into upper and lower parts by a separator 1, a current collector 3 made of a conductive sheet laminated above and below the electrode 2, and laminated on the upper and lower surfaces of each current collector 3. The lead plate 4 and the sealing portion 5 provided around the electrode 2 are adhered.

In the sealing portion 5 shown in FIG. 5 (a), a pair of sealing gaskets 6 are arranged above and below the separator 1 and the gaskets 6 and the gasket 6 and the current collector 3 are bonded by an adhesive or heat bonding. It is a structure.

Further, in the sealing portion 5 shown in FIG. 5 (b), a pair of sealing gaskets 6 are arranged above and below with the separator 1 sandwiched therebetween, and the gaskets 6 and the gasket 6 and the current collector 3 are sandwiched by a silicone sealant 7. In addition to bonding, the outermost periphery is sealed and fixed by the hot melt resin 8.

However, all such sealing structures have the technical problems described below.

<< Problems to be Solved by the Invention >> That is, regardless of the structure of any of the sealing portions 5, the structure itself is complicated and the number of assembling steps is increased.

In addition, in such a sealing portion 5, generally, the adhesive strength is insufficient, and particularly since the conductive sheet and the adhesive or the conductive sheet and the hot melt resin are bonded to each other with different materials, the adhesive strength is weak and internal pressure is applied even a little. There was a drawback that the electrolyte leaked.

Furthermore, the pressure and heating of the hot-melt resin causes wrinkles on the conductive sheet, which lowers the yield and serves as a path for liquid leakage.

The present invention solves the above drawbacks, and an object thereof is to provide a sealing structure for an electric double layer capacitor, which is easy to assemble, has high sealing strength, and has improved reliability.

<< Means for Solving the Problem >> In order to achieve the above object, the present invention is directed to a polarizable electrode in which a separator is disposed in the center, sheet-like current collectors disposed on both sides of the polarizable electrode, and In an electric double layer capacitor, which is arranged between current collectors and has a sealing portion that seals the outer peripheral portion of the polarizable electrode, a thermoplastic resin that constitutes the sealing portion is formed on the periphery of each current collector. The sealing gasket is integrated with the current collector.

<< Operation >> According to the above configuration, since the sealing gasket and the current collector are integrated, the bonding strength between the current collector and the sealing gasket becomes extremely high.

<< Embodiment >> An embodiment of the present invention will be described in detail below with reference to the drawings.

1 and 2 show a first embodiment of the present invention.

In the figure, 10 is a pair of polarizable electrodes that are stacked on top of each other via a separator 12, 14 is a current collector made of a conductive sheet that is stacked on the upper and lower surfaces of the polarizable electrode 10, and 16 is each current collector 14
It is a lead plate that is laminated and adhered to the upper and lower surfaces.

A ring-shaped sealing gasket 18 made of a thermoplastic resin is preliminarily integrally formed with the current collector 14 on the outer periphery of each of the current collectors 14, and the current collector 14 is used as a bottom surface, and a shallow container having an upper surface opened. The outer shell body 20 is formed.

The polarizable electrode 10 is a solid activated carbon in which dilute sulfuric acid is held as an electrolytic solution, and the separator 12 is
A porous material that is ion-permeable and electrically insulating is impregnated with an electrolyte.

Further, the conductive sheet constituting the current collector 14 is made by mixing and dispersing a conductive material such as carbon with a resin sheet having a relatively high melting point such as polyisobutylene or polyvinyl isobutyl ether as a binder, and preliminarily formed into a disc shape. Above, the sealing gasket 18 is integrated with the end side by injection molding.

The resin material forming the sealing gasket 18 is made of PP, PE, ABS resin which has a lower melting point than the constituent material of the conductive sheet and has a high durability against dilute sulfuric acid as an electrolyte.

At the time of molding, no pressure is applied to the current collector 14, and since the current collector 14 is integrally molded by supplying and solidifying the molten resin, it is molded with sufficient dimensional accuracy without generation of wrinkles. It

Further, the thickness of the sealing gasket 18 that determines the thickness dimension of the outer shell body 20 is set to approximately half of the total thickness, and a groove 18a that supports the peripheral edge of the separator 12 is provided on the inner periphery of the opening end surface thereof. Has been formed.

The assembly order in the above configuration is such that the polarizable electrode 10 is arranged inside the bottom side outer shell body 20 and the separator 12 is arranged on the upper surface thereof, while the other side is arranged inside the outer shell body 20 on the upper surface side. The polar electrode 10 is arranged, and in this state, the adhesive 22 is applied to the end face of each sealing gasket 18 which is the open end face of the outer shell body 20, the end faces of both are joined, and the electrode 10 is formed by pressing.
The separator 12 is laminated and arranged, and a closed container having upper and lower surfaces of the current collector 14 is obtained.

After that, the upper and lower lead plates 16 are adhered to the surface of each outer shell body 20 to complete the electric double layer capacitor.

As the adhesive used for joining the sealing gaskets 18 to each other, a material suitable for the above-mentioned various thermoplastic resin materials can be selected.

Further, it is also possible to form unevenness or the like for both positioning and improving sealing performance over the entire circumference of the joint surface.

FIG. 3 and FIG. 4 show a second embodiment when the present invention is applied to a laminated electric double layer capacitor.

In the figure, at the periphery of the current collector 30, the center of the inner peripheral portion of the ring-shaped sealing gasket 32 is integrally formed by injection molding on the upper and lower surfaces of the current collector 30, and the center is vertically moved by the current collector 20. A container-shaped outer shell 34 having a divided double-sided opening is configured.

The thickness of the sealing gasket 32 in the outer shell 34 is almost equal to the thickness of the unit cell in the laminated type, and a groove 32a for supporting a separator is formed on the inner periphery of the upper and lower opening surfaces.

In this embodiment, unit cells are formed between the outer shells 34 by laminating and bonding the outer shells 34 in order from the bottom through the adhesive 22, and an electric double layer capacitor having a withstand voltage corresponding to the total number of the stacked layers. Will be formed.

The outer shell body 20 shown in the first embodiment is used for the lowermost portion and the uppermost portion of this capacitor, and the lead plates 16 are laminated and adhered on the upper and lower surfaces thereof.

Further, in each of the embodiments, the case of forming a round shape is shown, but it goes without saying that the shape may be rectangular.

<Effects of the Invention> As described in detail in each of the embodiments above, in the sealing structure of the multilayer electric double-layer capacitor according to the present invention, the joint strength between the current collector and the sealing gasket is extremely high, and they are integrated. Therefore, there is no wrinkling of the current collector, the yield is improved, and the dimensional accuracy can be increased.

Further, since the polarizable electrodes and the like can be hermetically sealed by adhering the sealing gaskets to each other, the assembling work is extremely easy and the number of parts can be reduced as compared with the conventional case.

Further, since the sealing gaskets are bonded to each other with the same material, the bonding strength is high and the durability can be improved.

[Brief description of drawings]

1 is a partial sectional exploded perspective view of an electric double layer capacitor according to a first embodiment of the present invention, FIG. 2 is a partial sectional view showing the same assembled state, and FIG. 3 is an assembly according to a second embodiment of the present invention. FIG. 4 is a partial cross-sectional perspective view showing a state, FIG. 4 is a partial cross-sectional view showing the same assembled state, and FIGS. 5A and 5B are partial cross-sectional views showing a conventional sealing structure. 10 …… Polarizable electrode 12 …… Separator 4,30 …… Current collector 18,32 …… Seal gasket 20,34 …… Outer shell

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Mitsuhiro Nakamura 536-11 Shimbashi, Minato-ku, Tokyo Fuji Electric Chemical Co., Ltd. (72) Ken Kurabayashi 6-22-10 Minamioi, Shinagawa-ku, Tokyo In Isuzu Motors Ltd. (72) Inventor Yoshinobu Tsuchiya 6-22-10 Minamioi, Shinagawa-ku, Tokyo 6-22-10 Minamioi, Shinagawa-ku, Tokyo Inventor Nobuyuki Osawa 6-22-10 Minamioi, Shinagawa-ku, Tokyo Inside Isuzu Motors Ltd. (72) Seiichi Kito, 6-22-10 Minamioi, Shinagawa-ku, Tokyo Inside Isuzu Motors Ltd.

Claims (1)

[Scope of utility model registration request] 1. A polarizable electrode having a separator disposed in the center, sheet-shaped current collectors disposed on both sides of the polarizable electrode, and an outer peripheral portion of the polarizable electrode disposed between the current collectors. In an electric double layer capacitor comprising a sealing portion for sealing the sealing member, a sealing gasket made of a thermoplastic resin forming the sealing portion is integrated with the current collector at the periphery of each current collector. Characteristic electric double layer capacitor sealing structure.