JPH0652135U - Electric double layer capacitor - Google Patents

Abstract

(57) [Summary] [Purpose] When the internal pressure becomes high, the gas is released to the outside through the through hole, and after the gas is released, the through hole is closed again, so that the explosion proof mechanism continues to operate. Ready to use. [Structure] The through hole 22 penetrating the inside and outside of the gasket 10 is closed by an explosion-proof valve mechanism 24. This valve mechanism 2
4 is provided with a ball valve 28 made of an elastic body that closes the through hole 22 when the internal pressure is within the normal pressure range and opens when the internal pressure exceeds the normal pressure range. The through hole 22 is sealed with a microporous film 32 that selectively allows only gas to pass therethrough.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an electric double layer capacitor that releases gas when the internal pressure rises abnormally and can be reused after the gas is released.

[0002]

[Prior art]

 The electric double-layer capacitor is composed of an activated carbon electrode that is laminated inside and outside a frame-shaped gasket via a separator, and a metal collector plate that is arranged on the upper and lower surfaces of each activated carbon electrode and is connected to it. Has become. The activated carbon electrodes used are those impregnated with dilute sulfuric acid as an electrolytic solution. The positive and negative charges taken in through the current collector plates during charging are stored in the respective activated carbon electrodes, and the charges stored during discharging are also collected. Since it is gradually released to the outside through the electric plate, it can be used in the same usage pattern as a type of secondary battery.

[0003]

[Problems to be solved by the device]

 In an electric double layer capacitor of this structure, if charging is continued at a voltage higher than the rated value, the internal electrolytic solution will decompose and the internal pressure may increase. If the internal pressure becomes abnormally high, the current collector plate swells, reducing the electrical contact between the activated carbon electrode and the current collector plate, increasing internal resistance and causing performance deterioration.In addition, excessive pressure increase may cause rupture or other problems. Fear will also occur.

For this reason, an electric double layer capacitor provided with an explosion-proof mechanism has been conventionally proposed. In this publicly known device, a wrapper disc is provided in a part of the condenser, and when the pressure inside the condenser rises abnormally, the disc is destroyed just before the withstand pressure limit and gas is released to the outside. It has a structure.

However, in this structure, once the disk is broken, the inside and outside of the condenser communicate with each other, and hence the condenser cannot be used thereafter. The present invention solves the above problems, and its purpose is to release an electric double layer capacitor that releases gas when the internal pressure becomes abnormally high and can be used again after the gas is released. It is provided.

[0006]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, in the present invention, an activated carbon electrode which is vertically laminated inside a gasket via a separator, and a pair of current collector plates which are laminated and adhered to the upper and lower surfaces of the gasket and are connected to the respective electrodes described above. And an electrolytic solution injected into the activated carbon electrode, in the electric double layer capacitor, the gasket is formed with a through hole penetrating the inside and outside thereof, and the inside pressure of the through hole is within a normal pressure range. At this time, a valve mechanism made of an elastic body that closes the through hole and opens the through hole when the internal pressure rises abnormally is provided.

[0007] Preferably, the outlet end side of the through hole is sealed with a microporous film that selectively allows only gas to pass therethrough.

[0008]

[Action]

 According to the above configuration, when the internal pressure rises abnormally, the elastic body of the valve mechanism is elastically deformed or displaced in response to the pressure to open the through hole, thereby releasing the gas to the outside. Once the gas is released, the internal pressure drops, so the elastic body of the valve mechanism returns elastically again to close the through hole, preventing electrolyte inside from leaking to the outside, thereby making the capacitor reusable.

Further, when the outlet side of the through hole is blocked with a microporous film, only gas is allowed to selectively pass therethrough, so that liquid leakage due to gas ejection can be prevented.

[0010]

【Example】

 Hereinafter, an embodiment of the present invention will be described in detail. FIG. 1 is a side sectional view of an electric double layer capacitor according to the present invention. 10 is a polyethylene gasket formed in a rectangular frame shape, and 12 is a separator 1 inside the gasket 10 and arranged in the middle. A pair of activated carbon electrodes are stacked one on top of the other through 4, and 16 is a conductive film laminated on the top and bottom openings of the gasket 10 to cover the activated carbon electrode 12. A metal current collector plate 20 is fixed by hot melt adhesion via a frame-shaped hot melt film 18 made of modified polyethylene, and it is connected to each activated carbon electrode 12 by contacting the surface of the conductive film 16. , A basic structure of an electric double layer capacitor is manufactured.

In the present invention, the side wall of the gasket 10 is formed with a through hole 22 that communicates the inside and outside of the condenser, and the outside portion of the through hole 22 is expanded, and a valve mechanism 24 for explosion protection is installed therein. I'm out. That is, as shown in detail in FIG. 2, the valve mechanism 24 includes a valve chamber 26 formed by expanding the outer side of the through hole 22 and an end edge of the through hole 22 loosely fitted in the valve chamber 26. An elastic valve body serving as a valve seat, that is, a ball valve 28, and a pressing sheet 30 made of a rigid body that closes the outlet side end surface of the valve chamber 26 and constantly urges the ball valve 28 toward the valve seat side. ing. The pressing sheet 30 is provided with a plurality of openings 30a, and the openings 30a are closed by a microporous film 32 that selectively permeates only gas. The activated carbon electrode 12 is an activated carbon sheet which is impregnated by injecting and impregnating an electrolytic solution consisting of 30% by weight of dilute sulfuric acid. The injecting is performed through a through hole 22 and then through a valve mechanism 24. 22 is closed.

In the above structure, when the internal pressure of the electric double layer capacitor is abnormally increased from the normal pressure, the ball valve 28 elastically deforms as shown by an imaginary line in the figure to form a gap with the valve seat, The gas enters the valve chamber 26 and is released to the outside through the microporous film 32.

A mist-like liquid tends to be released along with the release of the gas, but the selective permeation action of the microporous film 32 prevents the liquid from leaking. Since the electrolyte solution is a non-volatile sulfuric acid solution, its gas component is only water vapor, and even if it is discharged to the outside, there is no fear of corroding the surroundings. Further, after the internal pressure has returned to the normal state due to the gas release, the ball valve 28 elastically returns to contact the valve seat again to close the through hole 22.

After returning, the concentration of sulfuric acid released as water vapor only changes, and the function itself as an electrolytic solution is not impaired, so it can be used again as an electric double layer capacitor.

FIGS. 3 (a) and 3 (b) show the relationship between the elapsed time, the thickness of the electric double layer capacitor, and the change in internal resistance when a 1.0 V continuous load was applied in a high temperature atmosphere of 60 ° C. Therefore, in the electric double layer capacitor without the explosion-proof valve mechanism, both the thickness and the internal resistance increase with the passage of time, whereas the valve mechanism 24 of the present invention has a constant value after increasing to some extent. Holds the value. The increase corresponds to an increase in internal pressure until the ball valve 28 operates, and a desired increase can be set by changing the operating pressure of the ball valve 28.

4 (a) to 4 (c) show another structural example of the explosion-proof valve mechanism. FIG. 4 (a) shows a valve body in which a cylindrical rubber valve 40 is used instead of the ball valve 28 to form a valve seat. Is configured to be closed. In (b), a valve 42 made of rubber is used to close the valve seat, and the tip of the valve seat is tapered so that it penetrates into the through hole 22. Further, in (c), the compression coil spring 46 is interposed between the plate-shaped valve body 44 and the pressing sheet 30 and the valve body 44 is constantly pressed against the valve seat side to close the through hole 22.

[0017]

[Effect of device]

 As described in detail in the above embodiments, in the electric double layer capacitor according to the present invention, when the internal pressure rises abnormally, the elastic body of the valve mechanism is elastically deformed or displaced according to the pressure. Gas is released by opening the through hole, and after releasing the gas, the elastic body of the valve mechanism returns elastically to close the through hole, and the electrolyte is retained inside without leaking. After that, the function of the electric double layer capacitor can be maintained again.

Further, when the exit side of the through hole is blocked with a microporous film, only gas is selectively passed, so liquid leakage due to gas ejection is prevented and corrosion of surrounding equipment due to liquid leakage is also prevented. it can.

[Brief description of drawings]

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

FIG. 2 is a partial cross-sectional view showing details of a valve mechanism provided in the gasket.

3 (a) and 3 (b) are graphs showing a relationship between a lapse of time, a cell thickness, and an internal resistance change in a state where a continuous load of 1.0 V is applied in a high temperature atmosphere.

4A to 4C are partial cross-sectional views showing another structural example of the valve mechanism.

[Explanation of symbols]

 10 Gasket 12 Activated Carbon Electrode 14 Separator 16 Conductive Film 18 Hot Melt Film 20 Current Collection Plate 22 Through Hole 24 Valve Mechanism 26 Valve Chamber 28, 40, 42, 44 Valve Body 30 Pressing Sheet 32 Microporous Film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Tatsuya Yamazaki, 5-16-11 Shimbashi, Minato-ku, Tokyo Fuji Electric Chemical Co., Ltd. (72) Kazuo Takada 5-36-11, Shimbashi, Minato-ku, Tokyo Fuji Electrochemical Co., Ltd.

Claims (2)

[Scope of utility model registration request] 1. An activated carbon electrode which is vertically laminated inside a gasket via a separator, a pair of current collector plates which are laminated and adhered to the upper and lower surfaces of the gasket and connected to each electrode, and the activated carbon electrode is poured. In an electric double layer capacitor provided with an electrolytic solution to be liquefied, the gasket has a through hole penetrating the inside and outside thereof, and the through hole is closed when the internal pressure is within a normal pressure range. An electric double-layer capacitor comprising a valve mechanism made of an elastic body that opens the through hole when the pressure rises abnormally. 2. The electric double layer capacitor according to claim 1, wherein the outlet end side of the through hole is sealed with a microporous film that selectively allows only gas to pass therethrough.