JP6942087B2 - Power storage device - Google Patents

Description

The present invention relates to a power storage device.

Conventionally, a so-called bipolar power storage module having a bipolar electrode having a positive electrode provided on one surface of an electrode plate and a negative electrode provided on the other surface is known (see Patent Document 1). Such a power storage module includes an electrode laminate in which a plurality of bipolar electrodes are laminated. On the side surface of the electrode laminate, a sealant for sealing between adjacent bipolar electrodes is provided.

Japanese Unexamined Patent Publication No. 2011-204386

It is conceivable to form a power storage device by stacking a plurality of power storage modules as described above with a conductive member interposed between them. By the way, in the power storage module as described above, the internal pressure of the electrode laminate may increase depending on the usage conditions and the like. In this case, if the sealing body has an overhang portion that wraps around from the side surface side of the electrode laminate to the end face side in the stacking direction, it is conceivable that the overhang portion is deformed to the outside in the stacking direction.

An object of the present invention is to provide a power storage device capable of suppressing deformation of an overhang portion of a power storage module.

The power storage device according to one aspect of the present invention is interposed between a plurality of power storage modules stacked along a predetermined stacking direction and adjacent power storage modules in the stacking direction, and also on both of the adjacent power storage modules. The power storage module includes a plurality of conductive members having a flow path that is in contact with each other and extends in a direction intersecting the stacking direction. And a sealing body provided on the side surface of the electrode laminated body to form a frame shape and seal between adjacent bipolar electrodes, and the sealing body is an electrode in the stacking direction from the side surface side of the electrode laminated body. It includes an overhang portion that wraps around to the end face side of the laminated body and exhibits an annular shape that surrounds the periphery of the conductive member when viewed from the stacking direction. A thick thick film portion is provided.

In the above power storage device, since the thick film portion is provided in the overhang portion of the sealing body of the power storage module, the internal pressure of the electrode laminate in one power storage module increases and the overhang portion is deformed to the outside in the stacking direction. In the situation, the thick film portion of the overhang portion of the power storage module comes into contact with the overhang portion of another adjacent power storage module. After the thick film portion comes into contact with the overhang portion, further deformation of the overhang portion is suppressed. Therefore, according to the power storage device, deformation of the overhang portion can be suppressed.

In the power storage device according to the other side surface, the overhang portion has a first portion facing the end of the flow path of the conductive member and a second portion not facing the end, and the thick film portion is the first. It is provided in at least one of a portion and a second portion.

In the power storage device related to the other side surface, the conductive member has a rectangular shape consisting of a pair of the first side and a pair of the second side when viewed from the stacking direction, and the flow path is parallel to the first side. The overhang portion extends in a rectangular shape surrounding the conductive member when viewed from the stacking direction, the first portion extends parallel to the second side of the conductive member, and the second portion is the first portion of the conductive member. It extends parallel to the side of 1.

In the power storage device according to the other side surface, the thick film portion is a band-shaped thick film portion provided over the entire length of the second portion.

In the power storage device according to the other side surface, the thick film portion is a plurality of protruding thick film portions provided side by side in at least one of the first portion and the second portion.

In the power storage device according to the other side surface, thick film portions are provided at positions facing each other of the overhang portions of the power storage modules adjacent to each other in the stacking direction.

In the power storage device according to the other side surface, the thick film portions provided at opposite positions of the overhang portions of the power storage modules adjacent to each other in the stacking direction are in contact with each other. In this case, since the thick film portions are in contact with each other before the overhang portion is deformed, the deformation of the overhang portion can be suppressed from the initial stage of deformation.

In the power storage device according to the other side surface, the thick film portions provided at opposite positions of the overhang portions of the power storage modules adjacent to each other in the stacking direction are separated from each other. In this case, it is possible to suppress excessive deformation of the overhang portion while allowing deformation of the overhang portion to some extent at the initial stage of deformation.

In the power storage device according to the other side surface, the separation distance between the thick film portions is shorter than the thickness of the conductive member in the stacking direction.

In the power storage device according to the other side surface, the encapsulant is a plurality of primary encapsulants provided at the edges of the plurality of bipolar electrodes, and a secondary encapsulant that surrounds the plurality of primary encapsulants from the outside. The overhang portion is a part of the secondary sealing body.

According to the present invention, there is provided a power storage device capable of suppressing deformation of an overhang portion of a power storage module.

It is sectional drawing which shows the power storage device which concerns on one Embodiment. It is sectional drawing which shows the power storage module shown in FIG. It is a figure which showed the laminated state of the power storage module and a conductive plate shown in FIG. It is a figure which showed the air cooling of the conductive plate shown in FIG. It is an enlarged view of the main part which showed the thick film part in the overhang part of the power storage module shown in FIG. It is a figure which showed (a) the thick film part in the long side part and (b) the thick film part in the short side part of the overhang part of the power storage module shown in FIG. It is sectional drawing which shows the state at the time of the internal pressure rise of the conventional power storage module.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following description, the same reference numerals will be used for the same or equivalent elements, and duplicate description will be omitted.
[Configuration of power storage device]

The power storage device 1 shown in FIG. 1 is used as a battery for various vehicles such as forklifts, hybrid vehicles, and electric vehicles. The power storage device 1 includes a power storage module stack 2 and a restraint member 3.

The power storage module stack 2 includes a plurality of (three in this embodiment) power storage modules 4 and a plurality of (four in this embodiment) conductive plates (conductive members) 5. The plurality of power storage modules 4 are stacked along a predetermined stacking direction D1. The power storage module 4 is a bipolar battery provided with a bipolar electrode 14 described later. The power storage module 4 has, for example, a rectangular shape when viewed from the stacking direction D1. The power storage module 4 is, for example, a secondary battery such as a nickel hydrogen secondary battery or a lithium ion secondary battery, or an electric double layer capacitor. In the following description, a case where the power storage module 4 is a nickel-metal hydride secondary battery will be illustrated.

The plurality of conductive plates 5 are interposed between the power storage modules 4 and 4 adjacent to each other in the stacking direction D1, and are arranged on both sides of the plurality of power storage modules 4 in the stacking direction D1. The positive electrode terminal 6 is electrically connected to the conductive plate 5 arranged on one side in the stacking direction D1 with respect to the plurality of power storage modules 4. The negative electrode terminal 7 is electrically connected to the conductive plate 5 arranged on the other side of the stacking direction D1 with respect to the plurality of power storage modules 4. The positive electrode terminal 6 and the negative electrode terminal 7 are drawn out from the edge of the conductive plate 5 in a direction orthogonal to the stacking direction D1. The positive electrode terminal 6 and the negative electrode terminal 7 charge and discharge the power storage device 1.

The restraint member 3 has a pair of end plates 8A and 8B that sandwich the power storage module stack 2 in the stacking direction D1 and apply a restraint load to the power storage module stack 2, and a fastening bolt B that fastens the end plates 8A and 8B to each other. It is equipped with a nut N. The end plates 8A and 8B are formed in a rectangular shape by, for example, metal. When viewed from the stacking direction D1, the outer edges of the end plates 8A and 8B are located outside the outer edge of the power storage module 4.

Each of the end plates 8A and 8B is provided with an insertion hole 8a at a portion located outside the power storage module stack 2 when viewed from the stacking direction D1. The fastening bolt B is passed from the insertion hole 8a of the end plate 8B on the other side in the stacking direction D1 toward the insertion hole 8a of the end plate 8A on the one side. A nut N is screwed into the tip portion of the fastening bolt B protruding from the insertion hole 8a of the end plate 8A. As a result, the power storage module 4 and the conductive plate 5 are sandwiched by the end plates 8A and 8B to be unitized as the power storage module stack 2, and a restraining load is applied to the power storage module stack 2 in the stacking direction D1. There is. Hereinafter, when the end plates 8A and 8B are not distinguished from each other, they may be collectively referred to as the end plate 8.

The power storage device 1 further includes a pair of insulating members 9A and 9B. The insulating members 9A and 9B are interposed between the end plates 8A and 8B and the conductive plates 5 adjacent to the end plates 8A and 8B, respectively. The insulating members 9A and 9B electrically insulate between the end plates 8A and 8B and the conductive plate 5, respectively. Each of the insulating members 9A and 9B is formed of, for example, a resin having an electrically insulating property. The insulating members 9A and 9B are provided on, for example, the inner surfaces of the end plates 8A and 8B (the surfaces on the power storage module laminate 2 side), respectively. Hereinafter, when the insulating members 9A and 9B are not distinguished from each other, they may be collectively referred to as the insulating member 9.
[Configuration of power storage module]

As shown in FIG. 2, the power storage module 4 includes an electrode laminated body 11 and a sealing body 12 that seals the electrode laminated body 11. The electrode laminate 11 is configured by laminating a plurality of bipolar electrodes 14 with a separator 13 interposed between them. In the present embodiment, the stacking direction of the electrode laminated body 11 coincides with the stacking direction D1 of the power storage module laminated body 2. The electrode laminate 11 has a side surface 11a formed by laminating the bipolar electrodes 14.

Each bipolar electrode 14 includes an electrode plate 15, a negative electrode 16 provided on one surface 15a of the electrode plate 15, and a positive electrode 17 provided on the other surface 15b of the electrode plate 15. The negative electrode 16 is a negative electrode active material layer formed by coating the negative electrode active material. The positive electrode 17 is a positive electrode active material layer formed by coating the positive electrode active material. In the electrode laminate 11, the negative electrode 16 of one bipolar electrode 14 faces the positive electrode 17 of one of the adjacent bipolar electrodes 14 in the stacking direction D1 via the separator 13. The positive electrode 17 of the one bipolar electrode 14 faces the negative electrode 16 of the other bipolar electrode 14 adjacent to each other in the stacking direction D1 via the separator 13.

In the electrode laminate 11, the positive electrode terminal electrode 18 is arranged at one end in the stacking direction D1. Further, in the electrode laminated body 11, the negative electrode terminal electrode 19 is arranged at the other end in the stacking direction D1. The positive electrode terminal electrode 18 includes an electrode plate 15 and a positive electrode 17 provided on the other surface 15b of the electrode plate 15. The positive electrode 17 of the positive electrode terminal electrode 18 faces the negative electrode 16 of the bipolar electrode 14 arranged at one end in the stacking direction D1 via the separator 13. The negative electrode terminal electrode 19 includes an electrode plate 15 and a negative electrode 16 provided on one surface 15a of the electrode plate 15. The negative electrode 16 of the negative electrode terminal electrode 19 faces the positive electrode 17 of the bipolar electrode 14 arranged at the other end in the stacking direction D1 via the separator 13.

The electrode plate 15 is made of, for example, a metal foil made of nickel or a nickel-plated steel plate, and is formed in a rectangular shape. The region on the edge portion 15c of the electrode plate 15 is an uncoated region in which the positive electrode active material and the negative electrode active material are not coated. Examples of the negative electrode active material constituting the negative electrode 16 include a hydrogen storage alloy. Examples of the positive electrode active material constituting the positive electrode 17 include nickel hydroxide.

The separator 13 is formed in a sheet shape, for example. Examples of the separator 13 include a porous film made of a polyolefin resin such as polyethylene (PE) and polypropylene (PP), a woven fabric made of polypropylene, polyethylene terephthalate (PET), methyl cellulose and the like, and a non-woven fabric. The separator 13 may be reinforced with a vinylidene fluoride resin compound. The separator 13 is not limited to a sheet shape, but may be formed in a bag shape.
[Detailed configuration of conductive plate]

As shown in FIGS. 3 and 4, each conductive plate 5 has a rectangular shape when viewed from the stacking direction D1. In the present embodiment, each conductive plate 5 has a rectangular shape composed of a pair of short sides (first side) and a pair of long sides (second side) when viewed from the stacking direction D1. ..

When each conductive plate 5 is located between adjacent power storage modules 4 in the stacking direction D1, as shown in FIG. 2, each conductive plate 5 is in contact with the electrode plate 15 of the positive electrode terminal electrode 18 of the upper power storage module 4 and is below. It is in contact with the electrode plate 15 of the negative electrode terminal electrode 19 of the power storage module 4 on the side. Therefore, the conductive plate 5 has a function as a connecting member for electrically connecting adjacent power storage modules 4 and 4 in series in the stacking direction D1.

Inside each conductive plate 5, a plurality of linear flow paths 5a through which a refrigerant flows are provided. Air is used as the refrigerant of the present embodiment. Each flow path 5a extends and penetrates so as to be parallel to the short side of the conductive plate 5. The conductive plate 5 is arranged so that its short side is parallel to the blowing direction D3. In the present embodiment, the ventilation direction D3 is a direction orthogonal to the stacking direction D1 and the drawing direction D2 from which the positive electrode terminal 6 and the negative electrode terminal 7 are pulled out. As shown in FIG. 4, a blower (or blower port) 30 for sending the cooling air to the power storage device 1 is located on the upstream side of the cooling air sent along the blowing direction D3. The cooling air sent from the blower 30 enters the flow path 5a through the opening at each end of the plurality of flow paths 5a arranged along the long side of the conductive plate 5, and passes through the flow path 5a. By flowing the cooling air through the flow path 5a in this way, the conductive plate 5 also has a function as a heat radiating member that dissipates heat generated by the power storage module 4.
[Detailed configuration of sealant]

The sealing body 12 is provided on the side surface 11a of the electrode laminated body 11, and includes a plurality of primary sealing bodies 21 and one secondary sealing body 22. The sealant 12 is made of a resin material such as polypropylene (PP), polyphenylene sulfide (PPS), or modified polyphenylene ether (modified PPE). In the present embodiment, the sealing body 12 has a rectangular frame shape as shown in FIG. More specifically, the sealing body 12 has a rectangular shape composed of a pair of long sides parallel to the drawing direction D2 and a pair of short sides parallel to the blowing direction D3. A plurality of (four in this example) mounting portions 25 for mounting safety valves (not shown) are provided on the portion corresponding to the short side of the sealing body 12. Each mounting portion 25 is composed of, for example, a plurality of through holes extending along the pull-out direction D2.

The primary sealant 21 is provided on the edge portion 15c of the electrode plate 15 (the edge portion of the bipolar electrode 14), respectively. The primary sealing body 21 is formed in a rectangular frame shape by, for example, injection molding of a resin, and is firmly bonded to the edge portion 15c of the electrode plate 15 by welding using ultrasonic waves or heat. The primary encapsulant 21 projects from the edge portion 15c in a direction orthogonal to the stacking direction D1, and is embedded in the secondary encapsulant 22 at the overhanging portion.

The secondary sealing body 22 is provided so as to surround the entire primary sealing body 21 from the outside. The secondary encapsulant 22 is formed in a rectangular frame shape by, for example, injection molding of a resin, and is welded to the outer surface of the primary encapsulant 21 by the heat during injection molding. The secondary sealant 22 seals between the adjacent bipolar electrodes 14 and 14 in the stacking direction D1. As a result, an internal space V is formed between the adjacent bipolar electrodes 14 and 14 in the stacking direction D1. The internal space V contains an electrolytic solution E composed of an alkaline solution such as an aqueous potassium hydroxide solution.

The secondary sealing body 22 is a pair of overhangs that cover a frame portion 23 extending along the side surface 11a of the electrode laminated body 11 and a part (that is, an outer edge portion) of the upper and lower end faces 11b of the electrode laminated body 11. It is configured to include a part 24 and the like. In the secondary sealing body 22, the frame portion 23 and the overhang portion 24 are integrally and continuously provided, and are provided so as to wrap around from the side surface 11a side to the end surface 11b side of the electrode laminate 11.

The frame portion 23 has a rectangular frame shape extending along the side surface 11a of the electrode laminate 11, and holds the overhanging portion of the primary sealing body 21. The upper surface overhang portion 24A of the pair of overhang portions 24 projects from the upper end of the frame portion 23 in the stacking direction D1 so as to extend toward the center side of the electrode laminate 11 when viewed from the stacking direction D1. It has an eaves-shaped cross section as shown in FIG. The upper surface overhang portion 24A covers at least a part of the primary sealing body 21 arranged at the upper end of the electrode laminated body 11, and the edge portion of the upper end surface 11b of the electrode laminated body 11 via the primary sealing body 21. Facing. Similarly, the lower surface overhang portion 24B of the pair of overhang portions 24 extends from the lower end of the frame portion 23 in the stacking direction D1 toward the center side of the electrode laminated body 11 when viewed from the stacking direction D1. It overhangs and has an eaves-shaped cross section as shown in FIG. The lower surface overhang portion 24B covers at least a part of the primary sealing body 21 arranged at the lower end of the electrode laminated body 11, and also covers the edge portion of the lower end surface 11b of the electrode laminated body 11.

The upper surface overhang portion 24A and the lower surface overhang portion 24B extend along a plane orthogonal to the stacking direction D1 and exhibit the same shape when viewed from the stacking direction D1. In the present embodiment, each overhang portion 24 exhibits a rectangular ring shape as shown in FIGS. 3 and 4. More specifically, each overhang portion 24 has a pair of strip-shaped long side portions 24a (first portion) extending parallel to the long side of the conductive plate 5 (that is, parallel to the drawing direction D2) and conductive. It exhibits a rectangular ring formed by a pair of strip-shaped short side portions 24b (second portion) extending parallel to the short side of the plate 5 (that is, parallel to the blowing direction D3). The width of the rectangular ring of each overhang portion 24 may be designed to be equal in width. Further, the other power storage modules 4 constituting the power storage module stack 2 also have overhang portions 24 having the same dimensions and the same shape, and the overhang portions 24 of the power storage modules 4 adjacent to each other in the stacking direction D1 are stacked in the stacking direction D1. Are facing each other.

As shown in FIG. 4, the inner edge of the overhang portion 24 is designed to have a dimension larger than the external dimension of the conductive plate 5 described above. Further, the power storage module 4 and the conductive plate 5 are aligned so that the conductive plate 5 fits inside the overhang portion 24 when they are overlapped with each other. Therefore, when viewed from the stacking direction D1, the overhang portion 24 surrounds the conductive plate 5, and the conductive plate 5 is not blocked by the overhang portion 24, and the electrode plate of the positive electrode terminal 18 of the power storage module 4 is not blocked. It is in contact with the electrode plate 15 of 15 and the negative electrode terminal electrode 19. At this time, the long side portion 24a of each overhang portion 24 faces the end opening of the flow path 5a of the conductive plate 5, and the short side portion 24b does not face the end opening of the flow path 5a.

Subsequently, the thick film portion of the overhang portion 24 will be described with reference to FIGS. 5 and 6.

The overhang portion 24 has a thick film portion 26 whose thickness in the stacking direction D1 is thicker than the thickness of other portions of the overhang portion 24. In the present embodiment, the overhang portion 24 in the portion other than the thick film portion 26 is designed to have the same thickness, which is thinner than the thickness of the thick film portion 26. Further, in the present embodiment, as shown in FIG. 5, the thick film portion 26 projects from a part of the overhang portion 24 to the outside in the stacking direction D1. That is, the upper surface overhang portion 24A is provided with the upper surface thick film portion 26A projecting upward along the stacking direction D1, and the lower surface overhang portion 24B is provided with the lower surface thick film portion 26B projecting downward along the stacking direction D1. Is provided. The upper surface thick film portion 26A and the lower surface thick film portion 26B are aligned with each other and face each other in a state of being separated by a predetermined separation distance d. In the present embodiment, the separation distance d between the upper surface thick film portion 26A and the lower surface thick film portion 26B is designed to be shorter than the thickness of the conductive plate 5 (that is, the length in the stacking direction D1).

In the long side portion 24a of the overhang portion 24, as shown in FIG. 6A, the thick film portion 26 is a plurality of protruding thick film portions that are regularly arranged. In the present embodiment, each protruding thick film portion 26 is provided so as to be offset from the position of the end opening of the flow path 5a so that the protruding thick film portion 26 does not block the end opening of the flow path 5a as much as possible. It is provided in. The thick film portions 26 do not necessarily have to be arranged regularly, and may be irregularly arranged as long as the adjacent thick film portions 26 are separated from each other. The protruding thick film portion 26 may be a columnar shape such as a cylinder or a prism, or may be a frustum shape such as a truncated cone. As shown in FIG. 6A, the long side portion 24a of the overhang portion 24 has a thickness in the stacking direction D1 in order to secure a path for the cooling air flowing from the blower 30 to the end opening of the flow path 5a. The thinnest thin film portion 28 in the overhang portion 24 is provided between the adjacent protruding thick film portions 26.

In the short side portion 24b of the overhang portion 24, as shown in FIG. 6B, the thick film portion 26 is a strip-shaped thick film portion provided over the entire length of the short side portion 24b. The band-shaped thick film portion 26 can also be composed of a plurality of continuous band-shaped thick film portions.

In the present embodiment, the thick film portion 26 is made of the same material as the overhang portion 24, and is integrally formed with the overhang portion 24. That is, when the secondary sealing body 22 is formed by injection molding of resin, the overhang portion 24 and the thick film portion 26 are integrally formed. At this time, the thick film portion 26 can be easily formed by providing the mold for injection molding with a recess corresponding to the shape of the thick film portion 26.
[Action effect]

Here, in the conventional power storage module, the deformation of the overhang portion that may occur when the internal pressure rises will be described.

In the conventional power storage module 40, when the internal pressure of the electrode laminate 11 rises due to usage conditions or the like, the overhang portion 24 may be deformed to the outside in the stacking direction D1 as shown in FIG. This is because the electrode laminate 11 is deformed so as to bulge in the stacking direction D1 due to an increase in the internal pressure, and the central portion of the electrode laminate 11 when viewed from the stacking direction D1 is significantly deformed as compared with the edge portion. Is. As a result, in the overhang portion 24, the tip portion on the side far from the frame portion 23 is deformed with the base end portion on the side closer to the frame portion 23 as the base point, and another overhang portion 24 facing away from the electrode laminate 11 Get closer to.

If the deformation of the overhang portion 24 becomes large, for example, the base end portion of the overhang portion 24 may be cracked or broken, and the sealing body 12 may be damaged. Alternatively, a gap may be formed between the sealing body 12 and the bipolar electrode 14. Further, the positive electrode terminal 18 of the electrode laminate 11 and the electrode plate 15 of the negative electrode terminal 19 may be cracked or broken. As a result, it is conceivable that the electrolytic solution E contained in the electrode laminate 11 leaks.

In the power storage device 1 described above, since the thick film portion 26 is provided in the overhang portion 24 of the power storage module 4, the internal pressure of the electrode laminate 11 rises in one power storage module 4, and the overhang portion 24 is in the stacking direction D1. The thick film portion 26 of the overhang portion 24 of the power storage module 4 comes into contact with the thick film portion 26 of the overhang portion 24 of another adjacent power storage module 4 in the situation of being deformed to the outside. After the thick film portions 26 are in contact with each other, further deformation of the overhang portion 24 is suppressed. Therefore, according to the power storage device 1, it is possible to suppress the excessive deformation of the overhang portion 24 while allowing the deformation of the overhang portion 24 to some extent at the initial stage of deformation.

The separation distance d between the upper surface thick film portion 26A and the lower surface thick film portion 26B can be adjusted according to the specifications of the power storage device 1 and the dimensions of the power storage module 4. For example, the separation distance d can be designed to be long under conditions where the deformation of the overhang portion 24 can be tolerated to some extent, and the separation distance d can be short under the conditions where the deformation of the overhang portion 24 is desired to be suppressed as much as possible. Can be designed. The upper surface thick film portion 26A and the lower surface thick film portion 26B may be in contact with each other at the time of manufacturing the power storage device 1 (that is, before the internal pressure rises). In this case, since the thick film portions 26 are in contact with each other before the overhang portion 24 is deformed, the deformation of the overhang portion 24 can be suppressed (theoretically, the deformation can be prevented) from the initial stage of deformation.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.

For example, the position and number of the thick film portions 26 can be changed as appropriate. By providing the thick film portion 26 on both the long side portion 24a and the short side portion 24b of the overhang portion 24, various deformations of the overhang portion 24 can be suppressed. The thick film portion 26 may be provided on either the long side portion 24a or the short side portion 24b of the overhang portion 24.

Regarding the thick film portion 26 provided on the long side portion 24a, since the long side portion 24a is located on the upstream side of the ventilation direction D3 and faces the end opening of the flow path 5a of the conductive plate 5, the flow path 5a The position, size, and number of the thick film portions 26 can be adjusted so that the passage of the flowing cooling air is sufficiently secured. When the conductive plate 5 is not provided with the flow path 5a, a strip-shaped thick film portion may be provided over the entire length on the long side portion 24a of the overhang portion 24, and the strip-shaped thick film portion and the short side portion 24a of the long side portion 24a may be provided. An annular thick film portion 26 composed of a strip-shaped thick film portion of the side portion 24b may be provided.

The thick film portion 26 provided on the short side portion 24b may be a plurality of protruding thick film portions regularly or irregularly arranged along the short side portion 24b instead of the band-shaped thick film portion. By providing the strip-shaped thick film portion 26 on the short side portion 24b, it is possible to effectively suppress the cooling air leakage due to the flow of the cooling air other than the flow path 5a of the conductive plate 5.

Further, although the aspect in which the thick film portion 26 is provided integrally with the overhang portion 24 has been described, the thick film portion 26 may be provided as a member different from the overhang portion 24 of the secondary sealing body 22. ..

Further, the thick film portion 26 does not have to be provided on both of the overhang portions 24 facing each other, and may be provided on either one of the overhang portions 24. Even in such an embodiment, when the internal pressure of the electrode laminate 11 rises, the thick film portion 26 of the overhang portion 24 of the power storage module 4 comes into contact with the overhang portion 24 of another adjacent power storage module 4, thereby overhanging. Deformation of the portion 24 can be suppressed. In such an embodiment, since it is not necessary to adjust the positions of the thick film portions so as to face each other, the configuration of the power storage device 1 is simplified and the power storage device 1 can be easily manufactured.

1 ... Power storage device, 4 ... Power storage module, 5 ... Conductive plate, 5a ... Flow path, 11 ... Electrode laminate, 12 ... Sealing body, 14 ... Bipolar electrode, 21 ... Primary sealing body, 22 ... Secondary sealing Body, 24 ... Overhang part, 26 ... Thick film part, D1 ... Stacking direction, D2 ... Pulling out direction, D3 ... Blower direction.

Claims (10)

Multiple power storage modules stacked along a predetermined stacking direction,
A plurality of conductive members having a flow path that is interposed between the adjacent power storage modules in the stacking direction, is in contact with both of the adjacent power storage modules, and extends in a direction intersecting the stacking direction. Prepare,
The power storage module has an electrode laminate in which a plurality of bipolar electrodes are laminated via a separator along the stacking direction, and a frame-like structure provided on a side surface of the electrode laminate, and between adjacent bipolar electrodes. With a sealant to seal,
The sealing body wraps around from the side surface side of the electrode laminate to the end surface side of the electrode laminate in the stacking direction, and is an overhang portion that exhibits an annular shape surrounding the conductive member when viewed from the stacking direction. Including
A power storage device in which the overhang portion is provided with a thick film portion whose thickness in the stacking direction is thicker than the thickness of other portions of the overhang portion. The overhang portion has a first portion facing the end of the flow path of the conductive member and a second portion not facing the end.
The power storage device according to claim 1, wherein the thick film portion is provided in at least one of the first portion and the second portion. The conductive member has a rectangular shape consisting of a pair of first side and a pair of second side when viewed from the stacking direction, and the flow path extends parallel to the first side.
The overhang portion exhibits a rectangular annular shape that surrounds the conductive member when viewed from the stacking direction, the first portion extends parallel to the second side of the conductive member, and the second portion is the conductive member. The power storage device according to claim 2, which extends parallel to the first side of the member. The power storage device according to claim 3, wherein the thick film portion is a band-shaped thick film portion provided over the entire length of the second portion. The power storage device according to claim 3, wherein the thick film portion is a plurality of protruding thick film portions provided side by side in at least one of the first portion and the second portion. The power storage device according to any one of claims 1 to 5, wherein the thick film parts are provided at positions facing each other of the overhang parts of the power storage modules adjacent to each other in the stacking direction. The power storage device according to claim 6, wherein the thick film portions provided at opposite positions of the overhang portions of the power storage modules adjacent to each other in the stacking direction are in contact with each other. The power storage device according to claim 6, wherein the thick film portions provided at opposite positions of the overhang portions of the power storage modules adjacent to each other in the stacking direction are separated from each other. The power storage device according to claim 8, wherein the separation distance between the thick film portions is shorter than the thickness of the conductive member in the stacking direction. The encapsulant has a plurality of primary encapsulants provided at the edges of the plurality of bipolar electrodes, and a secondary encapsulant that surrounds the plurality of primary encapsulants from the outside.
The power storage device according to any one of claims 1 to 9, wherein the overhang portion is a part of the secondary sealing body.

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