JP2011159849A - Electricity storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress an increase in planar dimension due to attachment of a degassing valve in an electric double layer capacitor or the like. <P>SOLUTION: An electricity storage laminate formed by alternately laminating polarizable electrodes and electrolyte layers is contained in a container. The container has such flexibility that it deforms under the atmospheric pressure and has a hole at a position where it superposes on a collector electrode of the electricity storage laminate when viewed in plane. A degassing structure is attached to an inner surface of the container to superpose on the hole. The degassing structure includes a housing for defining a passage through which a gas flows between an inner space and an outer space of the container. The degassing valve for releasing gas generated within the container to the outside of the container is disposed in the passage of the housing. A projection projecting toward the collector electrode is disposed to isolate the degassing valve from the collector electrode. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power storage device that includes an electrolyte layer in a container and has a gas venting mechanism that allows gas generated in the container to escape outside the container.

If the electric double layer capacitor is left in a high temperature environment for a long time in a charged state, inorganic gas such as CO, CO ₂ , H ₂ is generated due to electrolysis of water, and the decomposition reaction of the solvent of the electrolytic solution Due to this, organic gas is generated. When the generated gas is stored in the container, the adsorption of ions to the active material constituting the polarizable electrode is hindered, and the electric characteristics of the electric double layer capacitor are deteriorated. A gas vent valve is provided to allow the gas generated in the container to escape to the outside of the container.

  In order to make it difficult for the electrolytic solution to come into contact with the gas vent valve, the gas vent valve is attached at a position where it does not overlap with the collector electrode or the working electrode (polarizable electrode) in a plan view (Patent Document 1).

JP 2007-214537 A

  When the gas vent valve is attached at a position that does not overlap with the collector electrode or the polarizable electrode, an area for attaching the gas vent valve must be secured in plan view. For this reason, the planar dimension of the electric double layer capacitor becomes large. It is desired to suppress an increase in planar dimension due to the attachment of a gas vent valve.

According to one aspect of the invention,
Alternately stacked first polarizable electrodes and second polarizable electrodes, electrolyte layers disposed between the first polarizable electrodes and the second polarizable electrodes, the first polarizability A power storage laminate including a first collector electrode electrically connected to an electrode and a second collector electrode electrically connected to the second polarizable electrode;
A container that houses the electricity storage laminate, has flexibility to be deformed by atmospheric pressure, and has a hole provided at a position overlapping the first collector electrode in plan view;
A degassing structure attached to the inner surface of the container so as to overlap the hole,
The degassing structure is
A housing defining a passage through which gas flows between a space inside the container and a space outside the container;
A gas vent valve that is disposed in the passage of the housing and allows gas generated inside the container to escape to the outside of the container, but prevents gas from entering the inside of the container from the outside of the container;
There is provided a power storage device including a protruding portion protruding toward the first collector electrode so as to separate the gas vent valve from the first collector electrode.

According to another aspect of the invention,
Alternately stacked first polarizable electrodes and second polarizable electrodes, electrolyte layers disposed between the first polarizable electrodes and the second polarizable electrodes, the first polarizability A power storage laminate including a first collector electrode electrically connected to an electrode and a second collector electrode electrically connected to the second polarizable electrode;
A container that houses the electricity storage laminate, has flexibility to be deformed by atmospheric pressure, and has a hole provided at a position overlapping the first collector electrode in plan view;
A degassing structure attached to the inner surface of the container so as to overlap the hole,
The degassing structure is
A housing defining a passage through which gas flows between a space inside the container and a space outside the container;
A gas vent valve that is disposed in the passage of the housing and allows gas generated inside the container to escape to the outside of the container, but prevents gas from entering the inside of the container from the outside of the container;
A bottomed cylindrical protective member for housing the housing, the opening end of which is in contact with the inner surface of the container, and a hole or a groove is formed in the side wall to allow communication between the inner side and the outer side of the protective member. A power storage device having the protective member is provided.

  The protrusion prevents contact between the first collector electrode and the gas-liquid separation membrane. Deterioration of the gas-liquid separation membrane due to the electrolyte that wets the surface of the first collector electrode is suppressed.

  The protective member prevents contact between the first collector electrode and the gas vent valve. Deterioration of the gas vent valve due to the electrolyte that wets the surface of the first collector electrode is suppressed.

(1A) is a plan view of the power storage device according to Example 1, and (1B) to (1D) are cross-sectional views thereof. (2A) is a cross-sectional view of the degassing structure of the power storage device according to Example 1, (2B) is a cross-sectional view taken along the alternate long and short dash line 2B-2B in (2A), and (2C) is a gas exhausted It is sectional drawing of the degassing structure of the state performed. It is sectional drawing of the degassing structure by a reference example. 6 is a cross-sectional view of a power storage device according to a modification of Example 1. FIG. (5A) is a cross-sectional view of the degassing structure of the power storage device according to Example 2, and (5B) and (5C) are cross-sectional views of the degassing structure according to the modification. (6A) is a cross-sectional view of the degassing structure of the power storage device according to Example 3, and (6B) is a cross-sectional view of the degassing structure according to the modification.

[Example 1]
FIG. 1A is a plan view of a power storage device according to the first embodiment. A power storage laminate 11 is accommodated in the power storage container 10. The planar shape of the electricity storage container 10 is, for example, a rectangle with a slightly rounded vertex. The power storage laminate 11 includes a first collector electrode 21, a second collector electrode 22, a separator (electrolyte layer) 25, a first polarizable electrode 27, and a second polarizable electrode 28. The first collector electrode 21 and the second collector electrode 22 overlap each other in most regions. In FIG. 1A, the lateral width of the first polarizable electrode 27 is shown wider than the lateral width of the second polarizable electrode 28, but actually the lateral widths of both are substantially equal.

  The first collector electrode 21 and the second collector electrode 22 have extending portions 21A and 22A extending from the overlapping regions of the first collector electrode 21 and the second collector electrode 22 in opposite directions (upward and downward in FIG. 1A). The first polarizable electrode 27 and the second polarizable electrode 28 are overlapped with each other in almost the entire region, and from the outer peripheral line of the region where the first collector electrode 21 and the second collector electrode 22 overlap each other. Is also placed inside. The outer peripheral line of the separator 25 is located outside the region where the first collector electrode 21 and the second collector electrode 22 overlap. The extending portions 21 </ b> A and 22 </ b> A of the first collector electrode 21 and the second collector electrode 22 are led out to the outside of the outer periphery of the separator 25.

  The first collector electrode tab 12 and the second collector electrode tab 13 are drawn from the inside of the electricity storage container 10 to the outside of the electricity storage container 10 across the mutually parallel edges of the electricity storage container 10. The first collector electrode tab 12 and the second collector electrode tab 13 overlap the extended portion 21A of the first collector electrode 21 and the extended portion 22A of the second collector electrode 22, respectively. The two collector electrodes 22 are electrically connected. For example, the first collector electrode tab 12 and the second collector electrode tab 13 act as electrodes having opposite polarities.

  A gas vent hole 14 is formed in the electricity storage container 10. The gas vent hole 14 is disposed at a position overlapping the extended portion 21 </ b> A of the first collector electrode 21. The gas vent structure 15 is disposed at a position overlapping the gas vent hole 14.

  FIG. 1B is a cross-sectional view taken along one-dot chain line 1B-1B in FIG. 1A. The electricity storage container 10 includes two aluminum laminate films 10A and 10B. Aluminum laminate films 10 </ b> A and 10 </ b> B sandwich electricity storage laminate 11 and seal electricity storage laminate 11. One laminate film 10 </ b> B is substantially flat, and the other laminate film 10 </ b> A is deformed to reflect the shape of the power storage laminate 11. In FIG. 1B, descriptions of the separator 25, the first polarizable electrode 27, and the second polarizable electrode 28 are omitted.

  FIG. 1C shows a cross-sectional view of the electricity storage laminate 11. First polarizable electrodes 27 are formed on both surfaces of the first collector electrode 21, and second polarizable electrodes 28 are formed on both surfaces of the second collector electrode 22. For example, an aluminum foil is used for the first collector electrode 21 and the second collector electrode 22. The first polarizable electrode 27 can be formed, for example, by applying a slurry containing a binder kneaded with activated carbon particles to the surface of the first collector electrode 21 and then heating and fixing the slurry. The second polarizable electrode 28 can be formed by a similar method.

The first collector electrode 21 having the first polarizable electrode 27 formed on both sides and the second collector electrode 22 having the second polarizable electrode 28 formed on both sides are alternately stacked. A separator 25 is disposed between the first polarizable electrode 27 and the second polarizable electrode 28. For the separator 25, for example, cellulose paper is used. The cell roll paper is impregnated with an electrolytic solution. For example, a polarizable organic solvent such as propylene carbonate, ethylene carbonate, or ethyl methyl carbonate is used as the solvent for the electrolytic solution. As the electrolyte (supporting salt), a quaternary ammonium salt such as SBPB ₄ (spirobipyrrolidinium tetrafluoroborate) is used. The separator 25 prevents a short circuit between the first polarizable electrode 27 and the second polarizable electrode 28 and a short circuit between the first collector electrode 21 and the second collector electrode 22.

  Returning to FIG. 1B, the description will be continued. The extending portions 21 </ b> A of the plurality of first collector electrodes 21 are overlapped and ultrasonically welded to the first collector electrode tab 12. The extending portions 22 </ b> A of the plurality of second collector electrodes 22 are overlapped and ultrasonically welded to the second collector electrode tab 13. For example, an aluminum plate is used for the first collector tab 12 and the second collector tab 13. The second collector electrode 22, the first polarizable electrode 27, the second polarizable electrode 28, and the separator 25 are not disposed in the region where the extended portions of the first collector electrode 21 are stacked. For this reason, the portion where the extended portion 21A of the first collector electrode 21 is laminated is thinner than the region where the separator 25 and the like are disposed. Similarly, the portion where the extended portion 22A of the second collector electrode 22 is laminated is thinner than the region where the separator 25 and the like are disposed.

  The first collector electrode tab 12 and the second collector electrode tab 13 are led out to the outside of the electricity storage container 10 through between the laminate film 10A and the laminate film 10B. The first collector electrode tab 12 and the second collector electrode tab 13 are heat-sealed to the laminate film 10A and the laminate film 10B at the lead-out location. A tab film may be sandwiched between the first collector electrode tab 12 and the laminate films 10A and 10B, and between the second collector electrode tab 13 and the laminate films 10A and 10B. The tab film improves the sealing strength.

  A gas vent structure 15 is disposed between the extending portion 21A of the first collector electrode 21 and the laminate film 10A. The gas vent structure 15 is disposed so as to close the gas vent hole 14 and is heat-sealed to the laminate film 10A.

  The electricity storage container 10 is evacuated. For this reason, the laminate films 10 </ b> A and 10 </ b> B are deformed so as to follow the outer shapes of the power storage laminate 11 and the gas vent structure 15 due to atmospheric pressure. In the laminate film 10A around the region where the gas vent structure 15 is heat-sealed, a margin 18 such as a flaw that secures the gas vent structure 15 with respect to the first collecting electrode 21 is secured. Has been. When gas is generated in the storage container 10 and the pressure is increased, the margin 18 of the laminate film 10A is deformed, so that the gas vent structure 15 is lifted from the first collector electrode 21, and a gap is generated between the two. To do.

  FIG. 1D is a cross-sectional view taken along one-dot chain line 1D-1D in FIG. 1A. The laminated structure of the electricity storage laminate 11 is the same as that shown in FIGS. 1B and 1C. Laminate films 10 </ b> A and 10 </ b> B are heat-bonded to each other in a region outside the electricity storage laminate 11. In the cross section shown in FIG. 1D, the first collector electrode 21 and the second collector electrode 22 are not provided with extended portions. That is, relatively thin portions are not provided on both sides of the electricity storage laminate 11. For this reason, in the cross section shown in FIG. 1D, the inclination of the laminate film 10A covering the end face of the electricity storage laminate 11 is steeper than the inclination in the cross section shown in FIG. 1B.

  FIG. 2A shows a cross-sectional view of the gas vent structure 15. A cylindrical housing 30 is heat-sealed to the laminate film 10A at one end thereof. For example, polypropylene is used for the housing 30. The housing 30 includes a partition portion 30A that partitions the space inside the cylindrical portion in the axial direction. A through hole is provided substantially at the center of the partition portion 30A. A step is formed on the side surface of the through hole. A cavity inside the cylindrical portion of the housing 30 and a through hole formed in the partition portion 30A define a passage through which gas flows.

  The gas vent valve 31 includes an umbrella portion 31A, a stopper 31C, and a connecting portion 31B that connects both. The gas vent valve 31 is made of an elastic member such as silicone rubber or EPDM rubber (ethylene propylene diene rubber). A stopper 31C of the gas vent valve 31 is inserted into the through hole of the partition portion 30A from the outside (lamination film 10A side) and supported by a step on the inner surface. The outer peripheral portion of the umbrella portion 31A comes into contact with the outer surface of the partition portion 30A to block the gas passage. A cutout 35 is formed in a part of the step portion of the through hole of the partition portion 30A so that the gas passage 33 is not completely blocked by the stopper 31C.

  A gas-liquid separation membrane 32 is bonded to the inner surface of the partition portion 30A. The gas-liquid separation membrane 32 is adhered by, for example, heat fusion. The gas-liquid separation membrane 32 closes the through hole of the partition part 30A. For the gas-liquid separation membrane 32, for example, porous polytetrafluoroethylene (PTFE) is used. The gas generated in the storage container 10 permeates the gas-liquid separation membrane 32, but the electrolyte does not permeate the gas-liquid separation membrane 32.

  The housing 30 includes an annular projecting portion 34 projecting toward the first collector electrode 21 from a position where the gas-liquid separation membrane 32 is attached. In the initial state, the tip of the protrusion 34 is in contact with the first collector electrode 21. The surface of the first collector electrode 21 may be wetted with an electrolytic solution. The protrusion 34 prevents the first collecting electrode 21 from coming into contact with the gas-liquid separation film 32. For this reason, it is possible to prevent the gas-liquid separation membrane 32 from being deteriorated which may be caused by contact with the electrolytic solution.

  2B is a cross-sectional view taken along one-dot chain line 2B-2B in FIG. 2A. A stopper 31 </ b> C of the gas vent valve 31 is disposed substantially at the center of the cylindrical portion of the housing 30. The through hole of the partition part 30 </ b> A is closed with a gas-liquid separation film 32. The protrusion 34 completely surrounds the gas-liquid separation membrane 32 (without a break), and its tip is located on one virtual plane. Thereby, the function which prevents that the 1st collector 21 (FIG. 2A) contacts the gas-liquid separation film | membrane 32 can be maintained stably.

  When the protrusion 34 surrounds the gas-liquid separation film 32 without any break, the airtightness of the space surrounded by the gas-liquid separation film 32, the protrusion 34, and the first collector electrode 21 is improved. During assembly of the power storage device, the posture of the power storage device may change, and the top and bottom may be reversed compared to the normal posture during use of the power storage device. Since the hermeticity of the space where the gas-liquid separation membrane 32 is arranged is improved, it is possible to suppress the intrusion of the electrolyte into the space where the gas-liquid separation membrane 34 is arranged even when the top and bottom are reversed. it can.

  FIG. 2C shows a state when gas is generated in the storage container 10 and the pressure of the gas stored inside exceeds a certain threshold value. The laminate film 10 </ b> A is deformed by the gas pressure, and the gas vent structure 15 is lifted from the first collector electrode 21. As shown in FIG. 1B, since the margin portion 18 is provided in the laminate film 10A, the degassing structure 15 is allowed to move in the lifting direction.

  A gap is formed between the tip of the protrusion 34 and the first collector electrode 21. The gas passes through this gap, passes through the gas-liquid separation membrane 32, and flows into the through hole of the partition portion 30A. When the pressure in the through hole is increased, the vicinity of the outer periphery of the umbrella portion 31A of the gas vent valve 31 is lifted from the surface of the partition portion 30A, and a gap is formed therebetween. The gas passes through this gap and further passes through the gas vent hole 14 and is discharged to the outside of the electricity storage container 10. When the gas pressure in the storage container 10 is equal to or lower than the atmospheric pressure, the vicinity of the outer periphery of the umbrella part 31A is in close contact with the surface of the partition part 30A, so that no gas flows into the storage container 10 from the outside to the inside.

  In FIG. 3, sectional drawing of the degassing structure by a reference example is shown. In the degassing structure of the reference example shown in FIG. 3, the protruding portion 34 is removed from the degassing structure 15 according to the first embodiment shown in FIG. 2A. Other structures are the same as those of the gas vent structure 15 according to the first embodiment.

  Since the protruding portion 34 is removed, the first collecting electrode 21 is in contact with the gas-liquid separation membrane 32. Due to the action of the electrolytic solution that wets the surface of the first collector electrode 21, salt in the electrolytic solution may be deposited inside the pores of the porous gas-liquid separation membrane 32 and the pores may be blocked. is there. When the hole is closed, the gas permeability of the gas-liquid separation membrane 32 is lost.

  In the power storage device according to the first embodiment, deterioration of the gas-liquid separation membrane 32 can be prevented. Thereby, the function of letting the gas stored in the electrical storage container 10 escape to the outside of the container can be maintained, and the deterioration of the electrical storage characteristics can be suppressed.

  Moreover, in Example 1, as shown to FIG. 1B, the gas vent structure 15 is attached to the position which overlaps with the extending | stretching part 21A of the 1st collector 21. As shown in FIG. The portion where the stretched portions are laminated is thinner than the central portion of the electricity storage laminate 11. For this reason, there is almost no increase in the thickness of the power storage device by attaching the gas vent structure 15. Further, as shown in FIG. 1A, the dimension of the planar shape does not increase.

  In order to prevent contact between the first collector electrode 21 and the gas-liquid separation membrane 32, the height from the gas-liquid separation membrane 32 to the tip of the protruding portion 34 is preferably 1 mm or more.

  Further, as shown in FIG. 1B, the height of the gas vent structure 15 (the height of the housing 30 in FIG. 2A) is the total thickness of the first collector electrode tab 12 and the first collector electrode 21. In addition, it is preferable that the total height H2 of the degassing structure 15 is set to be equal to or less than the thickness H1 of the power storage laminate 11. Thereby, the upper surface of the gas vent structure 15 is prevented from protruding upward from the upper surface of the electricity storage stack 11.

  In order to prevent the electrolytic solution from coming into contact with the gas vent structure 15, a configuration in which the gas vent structure 15 is attached at a position where it does not overlap the power storage laminate 11 is also conceivable. For example, the degassing structure 15 can be attached to the side of the electricity storage stack 11 in the cross section shown in FIG. 1D. In this case, in plan view, a region for attaching the gas vent structure must be newly secured, and the size of the planar shape becomes large.

  A power storage device having a structure in which both the first collector electrode tab 12 and the second collector electrode tab 13 are pulled out from one edge of the power storage container 10 in the same direction has also been proposed. In such a structure, it is possible to attach the gas vent structure 15 between the first collector electrode tab 12 and the second collector electrode tab 13 without overlapping the power storage laminate 11. However, in such a structure, the width of each of the first collector electrode tab 12 and the second collector electrode tab 13 cannot be set to ½ or more of the edge length. Furthermore, in order to ensure the area | region which arrange | positions the gas vent structure 15, the width | variety of each of the 1st collector electrode tab 12 and the 2nd collector electrode tab 13 must be made narrower.

  As in the first embodiment, the first collector tab 12 and the second collector tab 13 are pulled out in opposite directions from the opposite edges, so that the first collector tab 12 and the second collector tab 13 are drawn. The width of each electrode tab 13 can be increased. As a result, the internal resistance of the power storage device can be reduced.

  Next, the assembly process of the power storage device according to the first embodiment will be described. The first polarizable electrode 27 is formed by applying activated carbon slurry to the surface of the first collector electrode 21 and heating it. Similarly, the second polarizable electrode 28 is formed by applying an activated carbon slurry to the surface of the second collector electrode 22 and heating it. At this stage, the first collector electrode 21 and the second collector electrode 22 are not distinguished.

  The first collector electrode 21, the second collector electrode 22, and the separator 25 are stacked. The extending portions 21 </ b> A of the first collector electrode 21 are overlapped and ultrasonically welded to the first collector electrode tab 12. The extending portions 22A of the second collector electrode 22 are overlapped and ultrasonically welded to the second collector electrode tab 13. The laminate film 10A is deformed so as to match the outer shape of the electricity storage laminate 11 (a depression is formed). The housing 30 is heat-welded to the deformed laminate film 10A. Note that a gas vent valve 31 and a gas-liquid separation membrane 32 are attached to the housing 30.

  The electricity storage laminate 11 is accommodated in the recess of the deformed laminate film 10A. A flat laminate film 10B is placed on the laminate film 10A, and the three edges are heat-sealed. For example, in FIG. 1A, the first laminate films 10A and 10B are heat-sealed at the edge from which the first collector electrode tab 12 and the second collector electrode tab 13 are drawn and at the other edge. .

  An electrolytic solution is injected into the electricity storage container 10 from the open edge. The electrolytic solution penetrates into the separator 25, the first polarizable electrode 27, and the second polarizable electrode 28. By disposing the electricity storage container 10 into which the electrolytic solution is injected in a vacuum, air in the minute cavities of the first polarizable electrode 27 and the second polarizable electrode 28 is discharged. In a vacuum, one edge of the remaining storage container 10 is heat-sealed. When taken out into the atmosphere, the laminate films 10 </ b> A and 10 </ b> B are deformed by the atmospheric pressure so as to match the outer shape of the electricity storage laminate 11.

  FIG. 4 is a cross-sectional view of a power storage device according to a modification of the first embodiment. Hereinafter, differences from the power storage device according to the first embodiment illustrated in FIG. 1B will be described. In the configuration shown in FIG. 1B, the gas vent structure 15 is in contact with the first collector electrode 21. In the modification shown in FIG. 4, the separator 25 in contact with the laminate film 10 </ b> A extends to the region of the extended portion 21 </ b> A of the first collector electrode 21. For this reason, the gas vent structure 15 contacts the separator 25. Other configurations are the same as those of the power storage device illustrated in FIG. 1B.

  The separator 25 is impregnated with an electrolytic solution. As shown in FIG. 2A, it is possible to prevent the electrolytic solution from coming into contact with the gas-liquid separation membrane 32 by providing the protruding portion 34 in the gas vent structure 15. As described above, even when the gas vent structure 15 is in contact with the separator 25, the effect of suppressing the deterioration of the gas-liquid separation membrane 32 is obtained as in the case of the first embodiment.

  When the electrolyte solution can be sufficiently prevented from entering the space where the gas vent valve 31 is disposed, the gas-liquid separation membrane 32 may not be disposed.

[Example 2]
FIG. 5A is a cross-sectional view of the gas vent structure 15 of the power storage device according to the second embodiment. Hereinafter, description will be made by paying attention to differences from the degassing structure 15 of the power storage device according to the first embodiment illustrated in FIG. 2A, and description of the same configuration will be omitted.

  In Example 1, as shown in FIG. 2A, the projecting portion 34 was integrally formed with the housing 30. In the second embodiment, no protrusion is formed on the housing 30. Instead, the vent structure 15 includes a protective member 38. The protection member 38 is, for example, a cylindrical member having both ends opened, and the housing 30 is accommodated therein. One end of the protection member 38 is in contact with the laminate film 10A. With the laminate film 10A as a reference surface, the other end of the protective member 38 extends to a position higher than the position where the gas-liquid separation membrane 32 is disposed. For this reason, the end of the protection member 38 is in contact with the first collector electrode 21, and the gas-liquid separation membrane 32 is not in contact with the first collector electrode 21. That is, a portion of the protective member 38 that protrudes from the position of the gas-liquid separation membrane 32 toward the first collector electrode 21 plays the same role as the protruding portion 34 of the first embodiment shown in FIG. 2A.

  In Example 1, when the gas-liquid separation membrane 32 shown in FIG. 2A is heat-sealed to the partition part 30A of the housing 30, the protruding part 34 may be thermally deformed. In the second embodiment, the housing 30 may be covered with the protective member 38 after the housing 30 to which the gas-liquid separation membrane 32 has been thermally fused is thermally fused to the laminate film 10A. For this reason, the protective member 38 functioning as the protruding portion 34 is not thermally deformed. The protective member 38 is made of a material that is difficult to be altered by the electrolytic solution, such as PTFE.

  The protective member 38 is supported by the laminate film 10 </ b> A by covering the housing 30.

  As shown in FIG. 5B, the protective member 38 may be fixed to the laminate film 10 </ b> A with an adhesive tape 39. The adhesive tape 39 covers the opening of the protective member 38 and is attached to the inner surface of the laminate film 10 </ b> A around the protective member 38. A hole 39 </ b> A is formed in a portion of the adhesive tape 39 that covers the opening of the protection member 38. The gas stored in the electricity storage container 10 reaches the gas-liquid separation membrane 32 through the hole 39A. By fixing the protection member 38 with the adhesive tape 39, it is possible to prevent the protection member 38 from falling off during manufacturing.

  As shown in FIG. 5C, the protection member 38 may have a bottomed cylindrical shape. Between the first collector electrode 21 and the gas-liquid separation membrane 32, the bottom 38A of the protective member 38 is disposed. A hole 38B for allowing gas to pass through is formed in the bottom 38A. By providing the bottom 38 </ b> A on the protection member 38, the effect of preventing the electrolytic solution from contacting the gas-liquid separation membrane 32 can be enhanced.

  5A to 5C, the inner wall surface of the protection member 38 and the outer wall surface of the housing 30 are separated from each other, but they may be in contact with each other.

[Example 3]
FIG. 6A is a cross-sectional view of the gas vent structure 15 of the power storage device according to the third embodiment. Hereinafter, differences from the degassing structure 15 of Example 1 shown in FIG. 2A will be described, and description of the same configuration will be omitted.

  The gas vent structure 15 according to the third embodiment is not attached with the gas-liquid separation membrane 34 shown in FIG. 2A. The housing 30 that holds the gas vent valve 31 is not provided with the protrusion 34 shown in FIG. 2A. A protective member 40 having a bottomed cylindrical shape is put on the housing 30. A gas reservoir 15 </ b> A is defined between the housing 30 and the protection member 40. A through hole 40 </ b> A is formed in the side wall of the protection member 40. The through hole 40A allows the space outside the protection member 40 to communicate with the gas reservoir 15A. The gas generated in the storage container 10 is transported to the passage 33 in the housing 30 through the through hole 40A and the gas reservoir 15A.

  The protection member 40 prevents the electrolytic solution from coming into contact with the gas vent valve 31. When the electrolytic solution contacts the gas vent valve 31 such as silicone rubber, the gas vent valve 31 is altered. By disposing the protective member 40, it is possible to prevent the electrolytic solution from contacting the gas vent valve 31.

  As shown in FIG. 6B, the protective member 40 may be fixed to the laminate film 10 </ b> A using an adhesive tape 43. The adhesive tape 43 is disposed in a band-shaped region including the protection member 40 in plan view. For this reason, the gas generated in the electricity storage container 10 flows into the through hole 40 </ b> A from the side of the adhesive tape 43.

  Since the protective member 40 is fixed to the laminate film 10A by the adhesive tape 43, the protective member 40 can be prevented from falling off during assembly.

  As shown in FIG. 6C, a groove 40B may be formed instead of the through hole 40A. The groove 40B is formed on the end surface of the protection member 40 that contacts the laminate film 10A, and allows the gas reservoir 15A to communicate with the space outside the protection member 40.

  Although the present invention has been described with reference to the embodiments, the present invention is not limited thereto. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

DESCRIPTION OF SYMBOLS 10 Electric storage container 10A, 10B Laminate film 11 Electric storage laminated body 12 1st collector electrode tab 13 2nd collector electrode tab 14 Gas vent hole 15 Gas vent structure 15A Gas reservoir 18 Spare part 21 First collector electrode 22 2nd Current collector 25 separator (electrolyte layer)
27 First polarizable electrode 28 Second polarizable electrode 30 Housing 31 Gas vent valve 31A Umbrella portion 31B Connecting portion 31C Stopper 32 Gas-liquid separation membrane 33 Passage 34 Protruding portion 35 Notch 38 Protective member 38A Bottom 39 Adhesive tape 40 Protective member 40A Through hole 43 Adhesive tape

Claims (10)

Alternately stacked first polarizable electrodes and second polarizable electrodes, electrolyte layers disposed between the first polarizable electrodes and the second polarizable electrodes, the first polarizability A power storage laminate including a first collector electrode electrically connected to an electrode and a second collector electrode electrically connected to the second polarizable electrode;
A container that houses the electricity storage laminate, has flexibility to be deformed by atmospheric pressure, and has a hole provided at a position overlapping the first collector electrode in plan view;
A degassing structure attached to the inner surface of the container so as to overlap the hole,
The degassing structure is
A housing defining a passage through which gas flows between a space inside the container and a space outside the container;
A gas vent valve that is disposed in the passage of the housing and allows gas generated inside the container to escape to the outside of the container, but prevents gas from entering the inside of the container from the outside of the container;
A power storage device including a protruding portion protruding toward the first collector electrode so as to separate the gas vent valve from the first collector electrode.   Furthermore, at the edge of the container, the container has a first collector electrode tab and a second collector electrode tab drawn out from the inside to the outside of the container in opposite directions, and the first collector electrode tab includes: The power storage device according to claim 1, wherein the second collector electrode tab is electrically connected to the first collector electrode, and the second collector electrode tab is electrically connected to the second collector electrode.   The gas vent structure overlaps with a connection portion between the first collector electrode tab and the first collector electrode in a plan view, and the first polarizable electrode and the second polarizable electrode are different from each other. The electrical storage apparatus of Claim 2 arrange | positioned in the position which does not overlap. In an initial state, the gas vent structure is in contact with the first collector electrode,
When gas is generated inside the container, the container is deformed by the pressure of the generated gas, so that the container is provided with a margin so that the degassing structure can be lifted from the first collector electrode. The power storage device according to any one of claims 1 to 3. The gas vent structure is further disposed between the gas vent valve and the first collector electrode in the passage defined by the housing so as to close the passage, and allows gas to pass therethrough. , The electrolyte solution has a gas-liquid separation membrane that does not permeate,
5. The power storage device according to claim 1, wherein the protrusion is configured to separate the gas-liquid separation membrane from the first collector electrode. 6.   The power storage device according to claim 1, wherein the protruding portion is molded integrally with the housing.   6. The gas venting structure according to claim 1, wherein the degassing structure includes a protective member that houses the housing and has one end contacting the inner surface of the container, and the protective member acts as the protruding portion. Power storage device. The protective member is
A cylindrical portion whose open end contacts the inner surface of the container;
A bottom portion disposed in a portion acting as the protruding portion of the cylindrical portion;
The power storage device according to claim 7, further comprising an opening provided in the lower portion.   The degassing structure includes an adhesive tape that is disposed between the protruding portion and the first collector electrode and bonded to the protruding portion, and further reaches the inner surface of the container and is bonded to the inner surface. The power storage device according to claim 1. Alternately stacked first polarizable electrodes and second polarizable electrodes, electrolyte layers disposed between the first polarizable electrodes and the second polarizable electrodes, the first polarizability A power storage laminate including a first collector electrode electrically connected to an electrode and a second collector electrode electrically connected to the second polarizable electrode;
A container that houses the electricity storage laminate, has flexibility to be deformed by atmospheric pressure, and has a hole provided at a position overlapping the first collector electrode in plan view;
A degassing structure attached to the inner surface of the container so as to overlap the hole,
The degassing structure is
A housing defining a passage through which gas flows between a space inside the container and a space outside the container;
A gas vent valve that is disposed in the passage of the housing and allows gas generated inside the container to escape to the outside of the container, but prevents gas from entering the inside of the container from the outside of the container;
A bottomed cylindrical protective member for housing the housing, the opening end of which is in contact with the inner surface of the container, and a hole or a groove is formed in the side wall to allow communication between the inner side and the outer side of the protective member. A power storage device having the protective member.

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