JP5127258B2 - Gas permeable safety valve and electrochemical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas penetration safety valve that can improve efficiency during regular time, safety at abnormality, reliability and has a high industrial value. <P>SOLUTION: The gas penetration pressure adjusting unit is provided with an electrolyte injecting part, a gas selection penetrating part 25 and an instantaneous breaking part 22 that is instantly broken at abnormalities. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention occurs when an electrochemical element such as a battery such as a lithium secondary battery or a nickel hydride secondary battery, a capacitor such as an aluminum electrolytic capacitor or an electric double layer capacitor, or a sensor such as an electric quantity memory element is used. Pressure control function that leaves various gases in the container and only the by-product gas is always dissipated outside the container, and excessive gas that is abnormally generated in the electrochemical element is instantaneously provided as a rupture hole in the gas permeable safety valve. The present invention relates to a thin film material, a structure, and an installation method having a function capable of causing explosion and instantaneously dissipating an abnormally generated gas from a fracture hole and preventing explosion of an electrochemical element.

In the prior art, explosion-proof safety valves are mainly used for batteries and capacitors. In the case of aluminum electrolytic capacitors and electric double layer capacitors, the typical structure is that a cross-step pressing process is applied to the bottom of the aluminum metal case to make the case thinner than other parts, reaching the safety limit. Then, the safety valve that breaks the stepped part is the main one.
Further, the conventional battery explosion爆安whole apparatus, when the internal pressure of the container of the battery becomes abnormally high in Tsu by the heating and overcurrent, broken at a predetermined pressure in order to prevent accidents caused by the explosion of the battery, A safety valve for venting is installed. In the case of other batteries, one using a stainless steel plate is disclosed in Japanese Patent Application Laid-Open No. 59-79965, and one using a nickel foil plate is described in Japanese Patent Application Laid-Open No. 10-172529.
For large stationary sealed lead-acid batteries, a catalyst plug is used to prevent corrosion due to acid mist around the battery, and the hydrogen gas and oxygen gas generated during charging and discharging are returned to water using the catalyst. Although the internal gas pressure is prevented from increasing, it requires more volume than a small battery with just a catalyst plug.
In Japanese Patent Laid-Open No. 5-159765, a porous membrane having open cells produced by stretching a fluororesin (PTFE) film is used. However, it is difficult to make the porosity uniform, and the liquid is lost. , the yield is poor, such as H ₂ O opaque features you or incomplete Tsu der, there are many problems on practical use.
Japanese Patent Application Laid-Open No. 2004-221129 has a constant pressure adjusting function, but does not have an instantaneous countermeasure function in case of abnormality.

The method of providing the stepped portion on the aluminum metal case is low in cost, but has a large variation in pressure at the time of breakage and is not reliable.
Safety valves using metal foil strips as disclosed in Japanese Patent Application Laid-Open Nos. 59-79965 and 10-172529 prevent explosion when the safety valve is activated, but are completely compatible with electrochemical devices such as batteries and capacitors. It becomes unusable and can no longer be used.
In addition, the catalyst plug is safe, but expensive, large in shape, and cannot be applied to a small electrochemical device. In addition, the fluororesin porous film has problems in mechanical strength, reliability, and yield, and has a problem that not only the gas in practical use but also the electrolytic solution is ejected simultaneously when the gas diffuses.
In recent years, electronic devices such as mobile phones, personal computers and PDAs have been miniaturized, and these electrochemical elements have been miniaturized. Furthermore, the heat resistance characteristics during solder reflow during manufacturing and the environmental conditions for using portable devices have become severe. Therefore, the gas generation problem of the electrochemical elements used for these is becoming serious.
In addition, with the commercialization of HEV vehicles (hybrid cars), HEV vehicles are used in cold regions, and large capacity electric double layer capacitors are put into practical use as a countermeasure against low temperatures in HEV vehicles. Therefore, a temperature cycle test of +60 to −30 ° C. is required, and countermeasures for gas generation of these electrochemical elements are urgently needed. As a countermeasure, the function of only a known safety valve has become a practical problem.
In recent years, electric double layer capacitors have been put into practical use for applications such as engine and catalyst assistance from the application of Break by wire. In addition, large electric double layer capacitors have been put into practical use for commercial high-speed copying machines. For such a large-sized and high-current application, it is necessary to commercialize a gas-permeable safety valve that instantaneously ruptures at the time of abnormality and has gas permeability above a set pressure.

The present invention solves these conventional problems, and aims to improve the following characteristics: 1) When the electrochemical device is used, only the gas is always dissipated out of the container above the set pressure. 2) Applicable to ultra small to large electrochemical devices. 3) The practical voltage of the electrochemical device is increased to 100 mV or more per device. 4) Extremely reliable. 5) Instantaneously, when the abnormal gas pressure rises due to an abnormal excessive current flow, the rupture hole is instantaneously ruptured to prevent the electrochemical element from exploding. 6) It has a structure in which a pressure-regulating gas permeable cartridge containing a rupture function and a gas permeable function can be instantaneously installed on the sealing plate. The purpose is.
Means for solving the problems of the present invention are as follows. 1) Using a foil strip made of Palladium-Silver (Pd-Ag) as a method of constantly dissipating the gas generated inside the electrochemical element constantly outside the container, Catalytically and electrochemically dissipates the internal gas out of the container. 2) A fine hole of 50 μm or less is provided in a 2-60 μm foil strip of nickel or a nickel-based alloy, and only the gas is diffused out of the container. 3) An organic film foil strip of 1 to 150 μm has the function of a plastic alloy and two or more types of plastic films superimposed to selectively dissipate only the target gas out of the container. H ₂ O has an impermeable function. 4) A composite functional membrane having a gas permeation function and an abnormal rupture function is housed in a cartridge shape, and has a structure in which the cartridge can be installed in the electrochemical element with a single touch after injecting the electrolyte into the electrochemical element.

(Electric double layer capacitor)
In recent years, electric double layer capacitors have been put into practical use for catalyst heating and engine assist when idling is stopped, in addition to the practical application of brake safety. When an electric double layer capacitor is applied for regenerative braking, a large current is charged and discharged instantly.
Instantaneous charging / discharging of a large current involves gas generation, so the gas permeable pressure regulating safety valve of the present invention solves blistering and leakage due to internal gas generation of the electric double layer capacitor, reduces -ΔC, It is an important member that guarantees reliability.
(For nickel metal hydride batteries)
Ni-mH batteries so far have incomplete safety valves, so if you run continuously on a mountain or steep slope, the battery generates heat, generates H ₂ gas, the internal pressure rises rapidly, and the charge and discharge efficiency by gas polarization is high. It was falling.
The gas permeable safety valve of the present invention can improve the efficiency at normal times, the safety and reliability at the time of abnormality, and has a great industrial value.

  Examples of the present invention will be described below with reference to FIGS. 1 to 9, and the conditions and results of the examples are shown in FIGS.

Example 1
The basic structure of the internal pressure adjusting foil strip of the electrochemical element used in the present invention will be described with reference to FIGS. FIG. 1 is a structural cross-sectional view of an electric double layer capacitor having a pressure regulating unit 3 (gas permeable pressure regulating unit) having a pressure regulating burst function according to the present invention. Inside the aluminum can outer case 1, an electrochemical element 2 is accommodated, and an anode 5 and a cathode 6 are provided as electrode terminals via a sealing plate.
As the container for the electrochemical element, a nickel-plated steel plate is used for a nickel metal hydride battery, and an aluminum material or an aluminum / stainless clad metal is used for an aluminum electrolytic capacitor, an electric double layer capacitor, or a lithium battery. The pressure regulating unit 3 having the pressure breaking function will be described in detail with reference to FIG. In FIG. 2, a gas permeable rupture valve main body 20 having a function of adjusting internal pressure and rupturing in the event of an abnormality, a gas selective permeable membrane 23 (gas selective permeable functional portion) , an electrolyte dew condensation preventing membrane 24, an airtight ring 26, and Various functional films made of the pressure-bonding ring 27 are accommodated in the cartridge 28.
FIG. 3 is a structural cross-sectional view of a gas permeable safety valve for an electric double layer capacitor. The pressure regulating unit 4 (gas permeable pressure regulating unit) has a configuration in which a pressure regulating unit receiving jig 31 is joined to a sealing plate 32 of an electrochemical element with a sealant 26, and a gas permeable pressure regulating cartridge 28 is used for gas dissipation. The upper lid 30 having the through hole 31 is configured so that it can be instantly installed with one touch.
The sealing plate 32 is usually molded by a butyl rubber 34 and a phenol resin 33 having resistance to electrolyte and gas impermeability.
The structure and assembly method of the gas permeation pressure regulation cartridge having the constant pressure regulation function of the present invention and having the instantaneous destruction function at the time of abnormality will be described with reference to FIG.
The gas permeable rupture valve main body 20 is integrated with a gas selective permeable membrane 23 made of an organic material and an electrolyte dew condensation prevention membrane 24 in a thin film shape, and a gas permeable pressure regulation using an airtight O-ring 26 and upper and lower pressure-bonding rings 27. It is the structure accommodated in a cartridge.
FIG. 2-b-1 is a sectional view of the gas permeable valve body, and FIG. 2-b-2 is a plan view of the gas permeable valve body. When the internal pressure of the electrochemical element is equal to or higher than the set pressure, the internally generated gas passes through the gas permselective membrane, and the gas permeation regulating part of the gas permeation rupture valve body 20 having innumerable fine holes of 0.1 to 50 μm. Pass through 21.
In addition, when an abnormal excessive current flows during charging / discharging of the electrochemical element, a large amount of gas is instantaneously generated, the internal pressure rapidly increases, and the excessive pressure rupture portion 22 provided in the gas permeation rupture valve body 20 is instantaneously generated. It has a structure that allows excessive gas to dissipate to the outside instantly without bursting and exploding the electrochemical element. The through hole diameter of the fine hole can be changed between the central part and the peripheral part. Also, the size of x, y, z of the overpressure rupture portion 22 in FIG. 2-b-1 is determined by the size of the electric double layer capacitor, the charge / discharge rate, and the rupture limit pressure. The limit pressure differs for automobiles, elevators, cranes, etc., but for automobiles, the limit current is normally 100 to 400 A, the time is 0.1 to 0.8 sec, and the limit current at the time of abnormality is 1000 A. . When such an excessive current flows, the internal gas pressure increases and the rupture valve instantaneously ruptures.

(Example 2)
An application example of an electric double layer capacitor will be described with reference to FIG. In FIG. 3, the sealing plate 32 and the pressure adjusting unit receiving jig 31 have been described above. The internal configuration of the gas permeation pressure adjusting cartridge 28 for the electric double layer capacitor is different. Requirements of the gas permselective membrane 23 is to have a CO, CO _2, transmission function of the H ₂ gas and H ₂ O opaque feature. The electrolyte condensation prevention film 24 prevents gas diffusion by causing electrolyte droplets or a liquid film due to condensation to form below the gas selective permeable membrane 23 when the automobile is accompanied by a temperature change while the vehicle is running in the cold district running mode. Therefore, the electrolyte dew condensation prevention film 24 is necessary for this measure.
The electrolyte condensation prevention film 24 uses a porous nonwoven fabric having chemical resistance, weather resistance, and mechanical strength, or a porous mixed paper made of dealkalized glass fibers and organic fibers. These materials are used after being subjected to water repellent treatment. As the nonwoven fiber material, split fibers made of polyethylene and polypropylene are excellent in chemical resistance and weather resistance.
In FIG. 3, the gas selective permeable membrane unit 25 includes a gas permeable rupture valve main body 20, a gas selective permeable membrane 23, and an electrolyte dew condensation prevention membrane 24. This functional gas permselective membrane unit is housed in a gas permeation pressure adjusting cartridge 28 with an airtight O-ring 26 interposed between upper and lower pressure-bonding rings 27.
When an electric double layer capacitor is manufactured, a predetermined electrolyte is injected into the electric double layer capacitor, and then the gas permeable pressure adjusting cartridge 28 is inserted into the pressure adjusting unit receiving jig 31 , and the pressure adjusting unit upper cover having the gas diffusion hole 31 is inserted. 30 is stored with one touch.
The one-touch storage structure can be applied to the present invention in the form of a hook button, a double screw method, a triple screw method, an eyelet method, or the like.

(Example 3)
In Example 3, the functional gas permeable membrane used in the present invention will be described in detail.
Gas barrier functional film As the water vapor gas impervious film, a fluorine-based film such as PTFE or PVDF is most suitable for the present invention. The product name EVAL (manufactured by Kuraray) is composed of polyethylene and polyvinyl alcohol, and is widely used as a gas barrier film for foods, building materials, and functional materials. In the present invention, this film is also effective.
Gas-permeable functional film
A thin film material made of silicon resin, polyacetal resin, or the like can selectively permeate gases such as CO ₂ , CO, and H ₂ . The silicon resin film is capable of CO ₂ permeation, but H ₂ O also permeates, so special processing for making H ₂ O impervious is necessary.
Structure of functional gas permeable membrane In the present invention, the above functional film is composited in a sheet form, and in consideration of mass production and a thin film sheet structure, such a functional resin is formed by a plastic alloy system. In addition, a functional resin is mixed and kneaded with a flexible and elastic resin such as butyl rubber in an alloy type, and processed into a thin film by stretching or extrusion molding. The surface of rubber or the like is coated with a polyvinyl alcohol solution and dried to prevent the passage of only water vapor and to allow other gases to pass through.
In the present invention, the test level was the film method, and the mass production was performed by the plastics alloy method and the two-layer coating method, but almost the same results were obtained.

Example 4
Application to Ni-mH Battery FIG. 4 shows a case where the present invention is applied to a nickel-hydrogen secondary battery. The basic structure is the structure shown in Example 2 above.
The major difference between the nickel-hydrogen secondary batteries is that the hydrogen gas impermeable film 40 is different from the application example of the electric double layer capacitor. Nickel-hydrogen rechargeable batteries require a function of impervious to hydrogen, carbon dioxide, and H ₂ O in principle because the efficiency decreases when hydrogen gas escapes, but the hydrogen gas pressure in the battery is set. When the pressure is exceeded, gas polarization is caused inside the battery, so that it is necessary to dissipate the gas, and it is necessary to activate the rupture mechanism during an internal short circuit or abnormal heating.
The hydrogen gas impermeable film 40 in FIG. 4 is put into practical use by using a plastic alloy type functional film having a structure in which a fluorine-based resin is dispersed in butyl rubber.

(Example 5)
Electrodeposited nickel porous foil body The electrodeposited nickel porous foil body and the fracture groove used in the present invention were prepared by an electrodeposition (deposit method). In the etching method, in the case of a hole of 10 μm or more, it can be manufactured. The material at that time may be other than nickel or nickel. However, in the case of holes with a precision of 10 μm or less, good nickel deposits can be obtained. The pore density depends on the thickness of the foil strip and is also related to the processing cost of the foil strip. About 20 μm is preferable for an AA battery to a coin-type battery electrochemical element, and 40 to 50 μm is preferable for an AA size. Moreover, it is preferable to use a foil strip of 100 to 150 μm in a square battery, an electric double layer capacitor of 500 to 4000 F, and an aluminum electrolytic capacitor of 500 to 5000 μF. The pore density of 1 μmΦ is preferably 50 to 100 / cm ^{2. In} the present invention, a pore density of 80 / cm ² was used. Note that the diameter of the pore diameter is X, the thickness of the foil strip is Y, and the ratio of Y / X is referred to as the aspect ratio. In the present invention, the aspect ratio is preferably 15 or more, and 150 or more has a high production cost. I will. The reason for using a pore diameter of 1 μmΦ is that when the internal pressure of the electrochemical element increases when the electrochemical element rises above 1 μmΦ, an electrolyte is ejected at the same time as the gas, leading to a liquid leakage phenomenon. This is because the property decreases. In addition, a pore diameter of 1 μmΦ has an industrial track record in mass production of metal screens and is advantageous in terms of cost.
Hereinafter, a method for mounting the gas permeation valve pressure regulating unit of the present invention on an electrochemical element will be described in detail in Examples.

(Example 6)
Application to Aluminum Foil Laminated Exterior Electrochemical Elements In recent years, mobile personal computers, PDAs, mobile phones, etc. have been further reduced in size and weight, and so far from metal exterior cases such as metal aluminum and stainless steel to aluminum Flexible sheet-type electrochemical elements (lithium secondary batteries, electric double layer capacitors, etc.) with foil laminated with an organic film such as polyethylene or polypropylene have entered the stage of practical use and mass production from the research stage. Such a pressure-resistant structure of the sheet-type outer case is structurally more fragile than the metal case. In reality, mobile phone accidents have occurred and countermeasures have been requested.
The present inventors have developed a gas permeable safety valve suitable for the sheet-type electrochemical element shown in FIGS. In FIG. 5, the sheet-type electrochemical element 202 and the cathode anode 203 are housed in an aluminum foil laminate type outer case 204, and a safety valve 201 having gas permeability and a rupturing function is mounted.
FIG. 6 is a structural cross-sectional view of the gas permeable safety valve of the present invention attached to an electrochemical element having a sheet type exterior structure. A gas passage hole 208 for gas dissipation is provided in the aluminum foil laminate outer case 204, and the gas permeable safety valve 205 (structure type in FIG. 4b) having gas permeation function and rupture function of the present invention is water resistant and gas barrier property. With the excellent adhesive 207, the exterior sheet and the safety valve exterior cover 206 are firmly joined to each other. Depending on the structure, high-frequency welding or heat welding is possible for this bonding. However, in consideration of cost and mass productivity, it is advantageous to bond with a modified olefin binder.

(Example 7)
Gas expansion test of sheet-type electrochemical element As a practical test of sheet-type electrochemical element, battery size of DoCoMo mobile phone P2008i type: electric double layer of the same size as a sheet-type lithium secondary battery with a shape of 35 * 60 * 3 mm A capacitor was manufactured, and a forced deterioration durability test was performed under various conditions shown in FIG. The lithium battery was subjected to a gas expansion test of the electrochemical device in a charged state at 4.2 ° C. for 200 hours at 4.2 ° C., and the electric double layer capacitor was charged at 70 ° C. for 2.3 hours at 2.3V.
As a result, as shown in FIG. 10, the gas permeable safety valve has a gas expansion of 0, and the one without the gas permeable safety valve has a shape change of 15 to 20% as usual. The excellent effect was confirmed.

(Example 8)
Attaching a gas permeable safety valve to a metal outer case 1
A large-sized electrochemical device for automobiles has a relatively large energy density and power density, and therefore a metal case with a thickness of about 2 to 5 mm is usually employed. In particular, in the test and mass production stage, the mounting method of the gas permeable safety valve in which the outer dimensions are constantly changing and the mold cannot be raised is particularly important.
FIG. 7 shows a structure for mounting the safety valve of the present invention on a thick metal case. The material of the outer case 210 of the gas permeable safety valve is preferably a valve metal such as aluminum, and these alloys can also be used. The exterior case 210 is trimmed by casting, forging, cutting, or the like, provided with a gas introduction hole 216 and a gas diffusion hole 212, and provided with a screw groove 218 and a top cover screw groove 211 for the metal exterior case. A screw groove 211 is provided in the gas seal packing 215 and the upper cover 213 of the safety valve of the gas permeable pressure adjusting cartridge 205.
As the gas permeable pressure adjusting cartridge 205, a cartridge having the cross-sectional structure shown in FIG.
The gas permeable pressure adjusting cartridge 205 is installed on a safety valve cradle 219 via a gas and electrolyte seal packing material 215. The packing material is made of NBR, SBR, butyl rubber, fluorine-based, or silicon- based elastomer, which is excellent in elasticity, durability, and airtightness.

Example 9
Method for Inserting into Metal Case FIG. 8 shows a sectional view of the structure when the gas permeable safety valve unit 230 is screwed into the metal case 232 of the electrochemical element. As the internal structure of the safety valve 230, the structure shown in FIGS. 1 and 2 is used.
In FIG. 8, the safety valve 230 is provided with a screw groove 235 in the insertion portion 231 and is inserted into a receiving screw groove 234 provided in the gas diffusion hole 233 of the metal case 232. In this case, the screw portion 235 has a structure in which a chemical-resistant seal bond is applied and locked.

(Example 10)
FIG. 9 is a structural cross-sectional view of an embodiment in which the safety valve unit 230 is press-fitted into the outer case 232 of the electrochemical element and attached.
A screw receiver 236 made of an elastic material is press-fitted into the gas diffusion hole 233 in the metal outer case 232 and is inserted into and attached to the opening of the metal case, and the safety valve unit 230 is inserted into the opening. The screw part 237 provided in the part 231 is press-fitted. A seal bond is applied in advance to the screw surface 237.

(Example 11)
Application of gas permeable safety valve to aluminum electrolytic capacitor and inverter circuit For large output inverters such as PEV cars, HEV cars, power robots, elevators, etc., 4-6 large aluminum electrolytic capacitors of 2000-5000μF It is used. In these inverters , the current voltage change within 1 minute is extremely large, the internal heat generation of the aluminum electrolytic capacitor is large, the electrolytic solution for the aluminum electrolytic capacitor is vaporized, the internal pressure due to this gas generation increases, and it is accumulated inside When the gas passes through the gasket and the high-pressure gas inside the metal case dissipates to the outside, the electrolyte explodes at the same time, and the electrolytic solution of the aluminum electrolytic capacitor decreases, the capacity of the aluminum electrolytic capacitor decreases, The current situation is that the inverter function is lowered and the aluminum electrolytic capacitor for the inverter needs to be replaced frequently.
As a countermeasure, the inverter for aluminum electrolytic capacitors 3000μF of H E V vehicles, with or without a gas-permeable safety valve, was carried out accelerated aging durability test shown in FIG. 11. The conditions were 70 ° C., a large current of 0 to 200 A was changed for 2 minutes, and 100,000 times of charging and discharging were repeated. The number of aluminum electrolytic capacitors for the inverter circuit was changed to 4 to 6 / unit, and the capacity change rate of the aluminum electrolytic capacitor after 100,000 cycles was indicated by −ΔC with respect to the initial value.
As is apparent from FIG. 11, the device equipped with the gas permeable safety valve of the present invention has a significantly lower −ΔC in the high temperature endurance test and the large-sized aluminum electrolysis than the conventional one without the safety valve. The possibility of reducing the number of capacitors used was obtained, and the possibility of reducing the weight of the vehicle body, saving space, reducing costs, and ensuring long-term high reliability was obtained.

The main block diagram of the safety valve which has the gas pressure bursting function of the Example of this invention. The structure sectional view of the gas permeation pressure regulation bursting function cartridge of the present invention. 1 is a cross-sectional view of a configuration of a gas permeable safety valve for an electric double layer capacitor according to the present invention. 1 is a cross-sectional view of a configuration of a gas-permeable safety valve for nickel-hydrogen batteries of the present invention. Sectional drawing of the sheet type electrochemical element equipped with the pressure regulation unit of this invention. The structure sectional view of the pressure regulation unit of the present invention. The structure sectional view of the safety valve for metal cases of the present invention. The reference drawing of the insertion method of the gas permeation safety valve to the metal case of the present invention. The reference drawing of the insertion method of the gas permeation safety valve to the metal case of the present invention. The figure which shows a forced deterioration durability test condition and a result. The figure which shows the result of a 3000 micro F aluminum electrolytic capacitor endurance test.

Explanation of symbols

20 Gas permeability壊裂valve body 21 gas transmission control unit 22 excessive crushing cleft 23 gas permselective membrane 24 electrolyte condensation prevention film 25 gas selective permeable membrane unit 26 airtight O-ring 27 crimped ring 28 gas permeable pressure regulating cartridge

Claims (10)

A gas permeation pressure adjusting unit includes a gas selective permeation function unit having a CO ₂ gas permeation function and an H ₂ O non-permeation function, a porous electrolyte dew condensation prevention film positioned under the gas selective permeation function unit, and a gas selection A gas permeable safety valve having an instantaneous rupture function portion that is located on the permeable function portion and instantaneously ruptures when an abnormality occurs.   2. The gas permeable safety valve according to claim 1, wherein the gas permeable pressure regulating unit is housed in a cartridge part having gas permeable through holes in an upper part and a lower part of the unit. The gas permeable property according to claim 2 , wherein the cartridge part having a gas permeation function has a mounting structure that can be easily mounted on the sealing plate part of the electrochemical element after one injection of the electrolyte into the electrochemical element. safety valve. The gas permeation according to any one of claims 1 to 3 , wherein the outer casing of the electrochemical element is made of an organic material, an organic film, aluminum, an aluminum alloy, stainless steel, or an aluminum laminate clad metal. Safety valve. The gas permeable safety valve according to any one of claims 1 to 4 , wherein the gas selective permeable membrane further has an H ₂ permeable function. 6. The method according to any one of claims 1 to 5 , which has a function of rupturing when an excessively large abnormal gas is generated and safely dissipating the gas from the electrochemical element instantaneously. The gas permeable safety valve as described. 7. The gas permeable safety valve according to claim 6 , wherein the function of breaking at an abnormal time is constituted by a nickel base alloy. An aluminum foil laminated sheet-like electrochemical element, wherein the gas permeable safety valve according to any one of claims 1 to 7 is attached by adhesion or welding. An electrochemical element comprising the gas permeable safety valve according to any one of claims 1 to 7 attached to a metal outer case by one-touch by screwing or press-fitting. An electrochemical device comprising the gas permeable safety valve according to any one of claims 1 to 7 in an aluminum electrolytic capacitor and applied to an inverter circuit and a power supply circuit for power.

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