JP6406491B2 - Power storage device - Google Patents

Description

  The present invention relates to an electricity storage device provided with a gas venting mechanism.

2. Description of the Related Art Conventionally, there is a type in which an explosion-proof valve is installed on a sealing body of a capacitor in preparation for a case where a gas such as hydrogen is generated inside a power storage device such as a capacitor and the internal pressure rises. In a capacitor, the electrolytic solution impregnated in the capacitor element may cause a chemical reaction and gas may be generated in the case due to long-term use or usage environment. This gas is mainly hydrogen gas resulting from the decomposition of moisture or gas due to vaporization of the electrolyte solution at a high temperature. If the internal pressure of the case increases due to this gas, the case may be damaged. . For this reason, when the pressure inside the capacitor reaches a certain level, the explosion-proof valve is ruptured, and the internal gas is discharged from the explosion-proof valve to prevent the capacitor itself from bursting (for example, Patent Document 1).

In addition to the explosion-proof valve, a capacitor equipped with an explosion-proof valve that opens the capacitor by rupturing the valve when the internal pressure of the capacitor rises can be used as a means to extend the life of the capacitor by delaying the operation of the explosion-proof valve as much as possible. Some have a gas vent valve made of a gas-permeable thin film rubber such as the above installed in the sealing body to suppress an increase in internal pressure (for example, see Patent Document 2).

Japanese Utility Model Publication No. 62-58035 (page 3, FIGS. 4 and 5) JP 2006-108185 A (page 4, FIG. 1)

By the way, the electrolytic solution impregnated in the capacitor element housed inside the closed capacitor may vaporize due to high temperature depending on the usage environment of the capacitor, and may adhere as water droplets to the inner surface of the sealing body that seals the outer case. is there. In addition, in order to extend the life of the capacitor, a predetermined amount of electrolyte may be sealed in the outer case. The electrolyte solution enclosed in the outer case may flow inside the capacitor and adhere as water droplets to the inner surface of the sealing body . Electrolyte that water droplets of this electrolytic solution travels along the inner surface of the sealing body and enters the inside of the bottomed cylindrical gas vent valve and stays at the bottom, which is the gas permeable portion of the gas vent valve, or enters the through hole. Adheres to the degassing valve in a state where it remains.

In addition, when the capacitor is mounted sideways with the degassing valve tilted sideways or diagonally as the capacitor mounted state, the electrolyte solution adhered to the inner wall of the outer case as described above, or the outer case The electrolyte sealed inside accumulates in the portion where the gas vent valve is disposed, and enters the cylindrical interior of the gas vent valve or the through-hole of the sealing body , and is easily retained.

  If the state where the electrolytic solution adheres to the permeable rubber continues, the gas permeation function is hindered, and the internal pressure of the capacitor rises and the degassing valve is likely to burst. There is a problem.

  In addition, the amount of gas generated inside the capacitor tends to increase as the size of the capacitor increases. Therefore, it is necessary to release a large amount of gas.

  The present invention has been made paying attention to such problems, and it is possible to achieve a long service life without water adhering to the gas permeation part of the gas vent valve and hindering the gas permeation function. An object of the present invention is to provide an electricity storage device provided with a gas vent valve that can maintain the electricity storage characteristics.

In order to solve the above problems, the electricity storage device of the present invention is:
An electrical storage device including a sealing body that seals an exterior case that stores an electrical storage element, and including a gas venting mechanism in the sealing body,
The degassing mechanism is
A convex portion formed on the storage element side of the sealing body;
A through-hole having an opening in the convex portion and penetrating the sealing body;
Consisting of a vent valve,
The degassing valve has a cylindrical shape with a bottom consisting of a cylindrical side wall and a bottom,
The side wall portion and the bottom portion of the gas vent valve cover the convex portion to block the opening.
According to this feature, since the convex portion formed on the sealing body is covered with the bottomed tubular gas vent valve, the bottom of the gas vent valve covering the opening is formed from the surface of the sealing body on which the convex portion is formed. Protruding. For this reason, the bottom of the gas vent valve serving as the gas permeable portion is not disposed in the concave portion in which moisture such as an electrolyte stays, and the structure is such that moisture does not easily stay in the bottom of the gas vent valve. As a result, the gas permeation function of the gas vent valve can be maintained as designed, and the life of the electricity storage device can be extended.

The electricity storage device of the present invention is characterized in that a concave portion is formed on the surface of the sealing body , and the convex portion is formed from the bottom surface in the concave portion.
According to this feature, at least a part of the convex portion is buried in the concave portion formed in the sealing body. Therefore, the bottom part of the gas vent valve attached to the convex part can be arranged so as to protrude from the bottom surface where the convex part in the concave part is formed, so that it is difficult for moisture to stay at the bottom part of the gas vent valve and the sealing body is made low. The height of the capacitor can be reduced as a whole.

The power storage device of the present invention is characterized in that the convex portion is formed to protrude from the concave portion of the sealing body .
According to this feature, since the convex portion formed on the bottom surface of the concave portion protrudes from the concave portion, the height of the convex portion can be increased while the portion protruding from the concave portion can be formed low. Can be realized. Therefore, the bottom part of the gas vent valve attached to the convex part can be arranged so as to protrude from the bottom surface where the convex part in the concave part is formed, so that it is difficult for water to stay in the bottom part of the gas vent valve and the convex part is high. Since it is formed, the contact area between the side wall portion of the gas vent valve and the convex portion is increased, the contact area is increased, and the fixing force between the convex portion and the gas vent valve is improved.

The electricity storage device of the present invention is characterized in that a rib is formed at a ground contact portion between the gas vent valve and the sealing body.
According to this feature, when the internal pressure rises, the pressure is concentrated on the ribs, so that the adhesion with the side surface of the convex portion is improved.

The electricity storage device of the present invention is characterized in that the gas vent valve includes the side wall portion and a bottom portion made of a material different from the side wall portion.
According to this feature, a desired gas permeation amount can be set by appropriately changing the material of the bottom according to the gas permeation amount that varies depending on the type and size of the electrolytic solution and the electricity storage device.

The electricity storage device according to the present invention is characterized in that an exhaust path forming means is formed on the side surface of the convex portion so that the gas permeated from the side wall portion of the gas vent valve flows into the through hole.
According to this feature, gas can be permeated also from the side wall portion of the gas vent valve. Thus, the area through which the gas permeates can be increased without changing the size of the gas vent valve. The permeation amount of the gas vent valve depends on the area and thickness of the portion through which the gas permeates. By the exhaust path formed on the side surface of the convex portion, gas can be permeated also from the side wall portion of the gas vent valve, and the amount of gas permeation can be increased.

The electricity storage device of the present invention is characterized in that the exhaust path forming means is a cut or a hole reaching the through hole at a portion covered by the gas vent valve on a side surface of the convex portion.
With this feature, the area of the opening portion that is closed by the gas vent valve can be appropriately changed. That is, by changing the size and number of the cuts and holes, a desired degassing amount can be designed without changing the thickness and size of the degassing valve.

It is front sectional drawing which shows the electric double layer capacitor which provided the gas venting mechanism in an Example. (A) is sectional drawing which shows the sealing body part of a degassing mechanism, (b) is a bottom view similarly. It is sectional drawing of the degassing valve in an Example. It is an exploded view which shows the degassing mechanism in an Example. It is sectional drawing which shows the degassing mechanism in an Example. It is sectional drawing which shows the degassing mechanism in another Example. It is sectional drawing which shows the gas vent valve in another Example.

  The form for implementing an electric double layer capacitor (henceforth capacitor 1) as an example of the electrical storage device provided with the gas venting mechanism concerning the present invention is explained below based on an example.

A capacitor 1 provided with a gas venting mechanism 20 according to the present invention will be described with reference to FIGS. As shown in FIG. 1, a capacitor 1 includes a capacitor element 2 that is a power storage element, an outer case 3 that stores the capacitor element 2 and an electrolytic solution, and a sealing body 4 that seals an opening of the outer case 3. And a gas venting mechanism 20 provided in the sealing body 4.

As shown in FIG. 1, the outer case 3 is formed by, for example, a metal plate such as aluminum in a bottomed cylindrical shape, and is circular, elliptical, or oval according to the shape of the capacitor element 2 housed inside. Alternatively, it is molded into a rectangle. The capacitor element 2 has a structure in which anode-side and cathode-side electrode foils are laminated or wound via a separator, and is formed in a circle, an ellipse, an oval, or a rectangle. A lead-out portion 6 is led out from an end portion of the capacitor element 2 and connected to an external terminal 5 integrally formed with the sealing body 4.

  Although not specifically shown in detail, the capacitor element 2 is formed by laminating a plurality of layers by collecting current collectors having polarizable electrodes with a separator interposed therebetween. The polarizable electrode has a structure in which two polarizable electrodes made of an activated carbon sheet are opposed to each other with a current collector made of an aluminum foil interposed therebetween.

As shown in FIGS. 1 to 5, the sealing body 4 is formed of a material having airtightness such as a resin material in a shape that matches the opening of the outer case 3, and is circular according to the shape of the opening. It forms the shape of a plate or the like, and is sealed in a sealed state by crimping the opening of the outer case 3. The sealing body 4 is provided with a gas venting mechanism 20 including a gas vent valve 10 while the external terminal 5 is insert-molded. In the present embodiment, the gas venting mechanism 20 includes a through hole 7, a convex portion 8, a gas vent valve 10, a buffer member 17, and a fixing member 18.

The sealing body 4 is a hard insulator, and is formed of, for example, a hard synthetic resin plate. As shown in FIG. 2 (a), the capacitor element 2 side of the sealing member 4 is a cylindrical protrusion 8 is formed integrally with the sealing member 4 protrudes from the surface of the sealing member 4 from the sealing member 4 . The sealing body 4 is formed with a through hole 7 that penetrates the sealing body 4, and the top 8 b of the convex portion 8 is formed with an opening 7 a of the through hole 7 as shown in FIG. Yes. That is, the through-hole 7 forms a discharge path for the gas generated inside the outer case 3 to the outside.

  The convex portion 8 is formed with a groove portion 8 a continuously provided over the side surface and the top portion 8 b. The groove portion 8 b reaches the opening portion 7 a of the through hole 7. That is, a gas discharge path is formed by the groove 8 a and the through hole 7.

An annular groove 9 surrounding the convex portion 8 is formed around the convex portion 8. On the opening side of the annular groove portion 9, a tapered portion 19 having a gradually increasing diameter is formed toward the surface of the sealing body 4.

  As shown in FIG. 3, the gas vent valve 10 of the present embodiment is integrally molded from a bottomed cylindrical elastic rubber such as silicon that covers the convex portion 8, and includes a side wall portion 12 that forms a cylindrical body portion, and a cylindrical bottom portion. , And a flange 16 that is formed at the opening end of the side wall 12 and has a diameter that is engaged with the annular groove 9. The inner diameter (inner wall part 13) of the side wall part 12 is formed smaller than the outer diameter of the convex part 8. Therefore, it is engaged with the convex part 8 and fixed. A plurality of annular ribs 14 in contact with the side surfaces of the convex portions 8 are formed on the inner wall portion 13, and an annular rib 14 in contact with the bottom portion 9 a is formed in the annular groove portion 9. Although details will be described later, even if the internal pressure increases, the sealing performance is maintained by the ribs 14. The degassing valve 10 allows the gas to pass through the bottom 11 and the side wall 12 when various gases are generated in the capacitor 1 and the internal pressure is increased. Has a function to reduce the internal pressure. A thin portion 15 thinner than the surrounding bottom portion 11 is formed at the center portion of the bottom portion 11 of the gas vent valve 10, and the gas permeability is enhanced by the thin portion 15. The thin portion 15 is set to have a size equivalent to that of the opening 7 a of the through hole 7. Further, when the internal pressure of the capacitor 1 suddenly increases, the thin portion 15 of the bottom portion 11 is ruptured to release the internal pressure and prevent the capacitor 1 from being ruptured.

Next, an attachment method will be described. FIG. 4 shows an exploded view of the degassing mechanism 20 of the capacitor 1. First, the flange 16 of the gas vent valve 10 is fitted into the annular groove 9 of the sealing body 4, and the gas vent valve 10 is attached to the convex portion 8. When the gas vent valve 10 is attached to the convex portion 8, the groove 8a formed in the convex portion 8 is covered with the side wall portion 12 and the bottom portion 11 of the gas vent valve 10, and in particular, the opening 7a formed in the convex portion 8 is the gas vent valve. 10 is covered by the thin wall portion 15 of the bottom 11. Thereafter, a buffer member 17 made of paper or rubber material is disposed on the collar portion 16. The buffer member 17 is an annular body having an annular portion 17b and a circular hole 17a formed at the center thereof, and the side wall portion 12 of the gas vent valve 10 is passed through the circular hole 17a. After disposing the buffer member 17, the fixing member 18 is fitted into the annular groove portion 9, and the flange portion 16 is pressed and brought into close contact with the bottom portion 9 a of the annular groove portion 9 to fix the gas vent valve 10 to the sealing body 4. Since the taper part 19 is provided in the opening part of the annular groove part 9, insertion of the gas vent valve 10, the buffer member 17, and the fixing member 18 becomes easy.

  The fixing member 18 is an annular body having an annular spring plate portion 18b and a circular hole 18a formed at the center thereof, and the gas vent valve 10 is passed through the circular hole 18a. The spring plate portion 18b is bent at an obtuse angle so that the diameter increases from the circular hole 18a toward the outer edge of the fixing member 18. When the fixing member 18 is press-fitted into the annular groove portion 9 and moves to the bottom portion 9a via the buffer member 17 and the flange portion 16, the spring plate portion 18b bent in an obtuse shape is deformed so that the diameter of the fixing member 18 increases, The outer edge of the spring plate portion 18b comes into contact with and engages with the side surface of the annular groove portion 9. That is, due to the elasticity of the fixing member 18, the spring plate portion 18 b is pressed against the side surface of the annular groove portion 9, and the gas vent valve 10 is firmly maintained in the annular groove portion 9 in this state. According to such a configuration, it is possible to prevent the gas vent valve 10 from coming off the convex portion 8.

  A gap may be provided between the circular hole 18 a of the fixing member 18 and the side wall portion 12 of the gas vent valve 10. By doing in this way, it can prevent that the side wall part 12 is damaged by the fixing member 18. FIG.

  The buffer member 17 is molded from rubber, resin, paper, or the like. By disposing the buffer member 17 between the flange portion 16 and the fixing member 18, the flange portion 16 is prevented from being damaged. In other words, the annular portion 17b of the buffer member 17 is disposed between the flange portion 16 of the gas vent valve 10 and the spring plate portion 18b of the fixing member 18, so that the weight when the fixing member 18 is pressed against the flange portion 16 is reduced. The portion 16 is prevented from being damaged.

FIG. 5 shows a state in which the gas vent valve 10, the buffer member 17, and the fixing member 18 are attached to the sealing body 4. The bottom 11 of the gas vent valve 10 protrudes from the surface of the sealing body 4. Thus, since the bottom part 11 of the gas vent valve 10 has a structure that is not disposed in a recess in which moisture such as an electrolytic solution stays, the electrolytic solution continuously adheres to the bottom part 11 and the side wall part 12 that are gas permeable parts. There is nothing to do. For this reason, it can prevent that a gas permeation function is inhibited by moisture, such as electrolyte solution.

Moreover, the side wall part 12 of the gas vent valve 10 is arrange | positioned so that the groove part 8a formed in the side surface of the convex part 8 protruded from the sealing body 4 may be covered. By setting it as such a structure, a clearance gap is formed between the groove part 8a and the inner wall part 13 of the gas vent valve 10. FIG. Since the part which covers the groove part 8a among the inner wall parts 13 is not contacting the side surface of the convex part 8, gas can permeate | transmit from the side wall part 12 of the degassing valve 10, and can be discharged | emitted from the opening part 7 outside.

  When the gas vent valve 10 is attached to the convex portion 8, the through hole 7 is closed by the bottom portion 11 of the gas vent valve 10. Since the top part 8b of the convex part 8 and the inner surface of the bottom part 11 of the gas vent valve 10 are arranged in contact with each other, the groove part 8a formed on the top part 8b of the convex part 8 forms a gap. The gas permeated from the side wall portion 12 flows to the opening portion 7a through the groove portion 8a, is discharged from the opening portion 7a to the through hole 7, and is discharged to the outside. That is, the groove 8a is a discharge path forming means in the present embodiment.

  By using the gas permeation part as the bottom part 11 and the side wall part 12, the amount of gas permeation can be improved. The gas permeation amount is defined by the thickness of the gas vent valve 10 and the area through which the gas permeates. In the present embodiment, not only the bottom portion 11 of the gas vent valve 10 that closes the opening 7a of the through hole 7 but also the side wall portion 12 of the gas vent valve 10 allows the gas to pass through the groove portion 8a. Can be transmitted. Further, by changing the number and size of the groove portions 8a, it is possible to adjust the gas permeation amount, and a desired gas permeation amount can be obtained without changing the size of the gas vent valve 10.

In addition, when the capacitor 1 is placed horizontally or the sealing body 4 is installed obliquely downward, the evaporated electrolytic solution or the electrolytic solution sealed in the outer case 3 may accumulate on the sealing body 4 side. Even in the case where the opening 7a of the convex portion 8 is blocked by the accumulated electrolyte, in the present invention, gas can be transmitted from the side surface in addition to the top portion 8a of the convex portion 8 protruding from the sealing body 4. Gas can be released to the outside. That is, since there are a plurality of gas permeation surfaces (the surface of the bottom portion 11 and the surface of the side wall portion 12 of the gas vent valve), the gas can permeate through the surface to which the electrolytic solution is difficult to adhere.

  As described above, the gas vent valve 10 of the present embodiment has the ribs 14 formed on the inner wall portion 13 and the flange portion 16. The gas generated in the exterior case 3 generates a pressure toward the convex portion 8 with respect to the gas vent valve 10. The rib 14 is formed at a position corresponding to the pressure when the internal pressure increases. When the internal pressure rises, as shown by the arrow X in the figure, pressure is applied to the flange portion 16 and the side wall portion 12 of the gas vent valve 10, and the ribs 14 formed on the flange portion 16 and the side wall portion 12 respectively more firmly form the annular groove portion. 9 can be in close contact with the bottom surface 9a and the side surface of the convex portion 8, and the sealing performance can be maintained.

A cylindrical portion 21 that communicates with the through hole 7 is formed outside the sealing body 4. The cylindrical portion 21 is provided with a bottomed cylindrical rubber moisture-proof valve 23. A groove is provided in the peripheral portion of the cylindrical portion 21. A standing wall portion 22 is formed across the groove. The standing wall portion 22 is set higher than the tube portion 21 and higher than the moisture-proof valve 23 covered on the tube portion 21. Thereby, the moisture-proof valve 23 is protected by the standing wall portion 22. The moisture-proof valve 23 is fixed in a state where it is pressed by a washer 24 from above.

  When the inside of the outer case 3 is filled with gas, the gas flows into the through hole 7 through the gas vent valve 10, and the internal pressure in the through hole 7 rises, the gas is moisture-proof through the notch portion 21 a formed in the cylindrical portion 21. It acts on the side wall part 23 a of the valve 23 to separate the side wall part 23 a from the cylinder part 21. Thereby, a gas discharge path is formed. The gas in the outer case 3 flows from the through hole 7 to the notch 21a and is released to the outside air. As a result, an explosion-proof function is obtained. That is, the gas filling the outer case 3 can be discharged according to the increase in the internal pressure in the outer case 3, the pressure increase in the outer case 3 can be suppressed, and the deformation of the capacitor 1 can be prevented. In addition, since the internal pressure of the outer case 3 can be suppressed by gas discharge, gas does not accumulate in the outer case 3 and the life of the capacitor 1 can be extended. Note that when the gas is suddenly generated and the pressure in the outer case 3 rapidly increases, the moisture-proof valve 23 is opened.

The washer 24 is a spring plate having an annular main body. This washer 24 is an example of a pressure contact member of the moisture-proof valve 23. On the peripheral edge of the main body that presses the moisture-proof valve 23, protruding pieces 24a are formed integrally with the main body at regular intervals. Each protrusion 24a is bent at an obtuse angle with respect to the main body. The diameter of the washer 24 including the projecting piece 24 a bent at an obtuse angle is formed larger than the diameter of the opening on the upper surface portion of the standing wall portion 22. The washer 24 is attached to the sealing body 4 by a projecting piece 24a that is press-fitted into the standing wall portion 22 and locked to the standing wall surface. That is, due to the elasticity and rigidity of the plurality of projecting pieces 24 a of the washer 24, the moisture-proof valve 23 is pressed against the cylinder portion 21, and the moisture-proof valve 23 is firmly maintained on the cylinder portion 21 in this state. With such a configuration, it is possible to prevent the moisture-proof valve 23 from coming off from the cylinder portion 21.

By disposing the moisture-proof valve 23 in this way, moisture entering from the outside through the through hole 7 can be prevented. Further, the moisture concentration in the capacitor 1 is lower than the moisture concentration in the external air atmosphere. For this reason, external moisture can easily enter the capacitor 1, and the gas-liquid separation action of the gas vent valve 10 may be reduced. Therefore, by disposing the moisture-proof valve 23 on the outside of the gas vent valve 10, contact between the gas vent valve 10 and the external air atmosphere can be prevented, and moisture can be further prevented from entering. Further, when the gas is released and the internal pressure in the outer case 3 is reduced, the external pressure is applied to the bottom 11 of the gas vent valve 10 through the through hole 7, and the gas vent valve 10 may be detached from the convex portion 8. However, by disposing the moisture-proof valve 23 and closing the outside of the sealing body 4 of the through hole 7, external pressure applied to the bottom 11 of the gas vent valve 10 through the through hole 7 is prevented and the fixing force of the gas vent valve 10 is maintained. it can.

  Although the embodiments of the present invention have been described with reference to the drawings, the specific configuration is not limited to these embodiments, and modifications and additions within the scope of the present invention are included in the present invention. It is.

In the said Example, although the convex part 8 protruded and formed from the annular groove part 9, what is necessary is just the height which the bottom part 11 of the gas vent valve 10 protrudes from the surface of the sealing body 4 which forms a convex part. By doing so, the bottom part 11 of the gas vent valve 10 prevents the water droplets such as the electrolyte from staying and obstructs the gas permeability, and lowers the height of the sealing body. Can be realized.

  In the above embodiment, the groove portion 8a is formed on the side surface of the convex portion 8 as the gas discharge path forming means, but is not limited thereto. For example, it is good also as a structure which forms a some projection part in the side surface of the convex part 8, and forms a clearance gap between the inner wall part 13 of the gas vent valve 10, and the side surface of the convex part 8. FIG. Moreover, although the groove part 8a may be formed in the whole side surface of the convex part 8, you may form only in the opening part 7a vicinity. By not forming the gas exhaust path on the side surface of the convex portion 8 facing the vicinity of the flange portion 16 of the side wall portion 12, the contact area between the inner wall portion 13 and the convex portion 8 is increased, and the fixing force is improved.

  Alternatively, the gas permeation portion may be formed in the side wall portion 12 of the gas vent valve 10 by forming radial cuts or holes on the side surface of the convex portion 8, and the through hole 7 and the side wall portion 12 of the gas vent valve 10. There should be a gas release path between the two. For example, as shown in FIG. 6, a radial slit 25 may be formed on the side surface of the convex portion 8 and covered with the side wall portion 12 of the gas vent valve 10. The slit 25 is an example of incision. With such a structure, gas can be transmitted from the side wall portion 12 of the gas vent valve 10 through the slit 25.

  Since the gas permeation amount is proportional to the area of the gas vent valve 10 in contact with the through hole 7, the gas exhaust path forming means such as a hole or a cut formed in the side surface of the convex portion 8 according to the desired gas permeation amount. The number and size may be set as appropriate.

  Moreover, in the said Example, although silicon was used as a material of the degassing valve 10, it is not restricted to this, It is applicable if it is a material with gas-liquid separability and gas permeability.

  Moreover, in the said Example, although the gas vent valve 10 was formed by integral molding of the bottom part 11 and the side wall part 12, you may form the bottom part with a member different from the side wall part 12 not only in this. For example, as shown in FIG. 7A, a sheet-like gas-liquid separation sheet 26 may be arranged to cover the opening on the capacitor element 2 side of the cylindrical side wall portion 12 and may be used as the bottom portion. The side wall portion 12 and the sheet 26 may be integrally formed by an adhesive, heat fusion, or the like. Moreover, as shown in FIG.7 (b), it is good also as a bottom part by arrange | positioning the bottomed cylindrical gas-liquid separation lid | cover 27 which covers the opening part of the cylindrical side wall part 12. As shown in FIG. In this case, the opening part of the cylindrical side wall part 12 may be fitted into the lid 27 and fixed, and the side wall part 12 and the lid 27 may be integrated. Similarly to the sheet 26, an adhesive, heat fusion, or the like is used. And may be integrated. As the sheet | seat 26 and the lid | cover 27, what is necessary is just a gas-liquid-separable sheet | seat and lid | cover materials, such as a polytetrafluoroethylene and a fluororesin, for example, and should just select it suitably based on the gas permeability which has for every member. By adopting such a configuration, it is possible to change the material of the sheet 26 and the lid 27 according to the type of gas to be generated and the amount of gas to be predicted, and set a desired gas permeation amount.

  Further, the side wall portion 12 of the gas vent valve 10 may be formed so that the diameter gradually decreases from the flange portion 16 side toward the bottom portion 11. Thus, by making the side wall part 12 incline toward the bottom part 11 from the flange part 16 side, it becomes easy to drain even if moisture such as an electrolytic solution adheres to the side wall part 12, and gas permeation from the side wall part 12 is prevented. It can prevent being inhibited.

  Further, the annular groove 9 around the convex portion 8 may be formed so as to gradually increase in diameter from the opening of the annular groove 9 toward the bottom 9 a of the annular groove 9. By doing in this way, since the collar part 16, the buffer member 17, and the fixing member 18 of the gas vent valve 10 fit more strongly, it can prevent falling off more. Further, a protrusion may be formed on the side surface of the annular groove 9. By doing in this way, it can prevent that the gas vent valve 10, the buffer member 17, and the fixing member 18 fall off.

Moreover, in the said Example, although the sealing body 4 provided with the gas vent valve 10 is applied to the electric double layer capacitor, the kind of electrical storage device to which the sealing body 4 according to the present invention is applied is as follows. The capacitor is not necessarily limited to the electric double layer capacitor 1, and may be, for example, an electrolytic capacitor, or may be applied to various capacitors and batteries that generate a large amount of various gases such as hydrogen and carbon monoxide.

1 Electric double layer capacitor (capacitor)
2 Capacitor element 3 Exterior case 4 Sealing body 5 External terminal 6 Lead-out part 7 Through-hole 7a Opening part 7a
8 convex portion 8a groove portion 8b top portion 9 annular groove portion 9a bottom portion 10 degassing valve 11 bottom portion 12 side wall portion 13 inner wall portion 14 rib 15 thin wall portion 16 flange portion 17 buffer member 17a circular hole 17b annular portion 18 fixing member 18a circular hole 18b spring plate Part 19 taper part 20 degassing mechanism 21 cylinder part 21a notch part 22 standing wall part 23 moisture-proof valve 23a side wall part 24 washer 24a projecting piece 25 slit 26 sheet 27 lid

Claims (7)

An electrical storage device including a sealing body that seals an exterior case that stores an electrical storage element, and including a gas venting mechanism in the sealing body,
The degassing mechanism is
A convex portion formed on the storage element side of the sealing body;
An annular groove portion surrounding the convex portion;
A through-hole having an opening in the convex portion and penetrating the sealing body;
Consisting of a vent valve,
The degassing valve is a bottomed cylindrical shape comprising a cylindrical side wall portion, a bottom portion, and a flange portion formed on the side wall portion,
A rib that contacts the annular groove is formed on the flange,
Covering the convex part with the side wall part and the bottom part of the degassing valve to close the opening,
The flange portion of the gas vent valve is engaged with the annular groove portion, an annular fixing member is fitted into the annular groove portion, and the flange portion is pressed against the bottom portion of the annular groove portion to fix the gas vent valve. A power storage device characterized. The electrical storage device according to claim 1, wherein a concave portion is formed on a surface of the sealing body , and the convex portion is formed from a bottom surface in the concave portion. The power storage device according to claim 1, wherein the convex portion is formed to protrude from the concave portion of the sealing body .   4. The power storage device according to claim 1, wherein an exhaust path forming unit is formed on a side surface of the convex portion to allow gas that has permeated from the side wall portion of the gas vent valve to flow into the through hole.   5. The electric storage device according to claim 4, wherein the exhaust path forming means is a cut or a hole that reaches the through hole at a portion of the side surface of the convex portion that is covered by the gas vent valve.   The power storage device according to claim 1, wherein a tapered portion is provided at an opening of the annular groove.   The electricity storage device according to claim 1, wherein an annular rib that abuts against a side surface of the convex portion is provided on an inner wall portion of the side wall portion.