Power storage module

Abstract

This power storage module is provided with: an electrode laminate having a plurality of electrodes that include a current collector and are laminated in a first direction; a first resin part provided on the electrode laminate so as to form an internal space between the current collectors adjacent in the first direction and to close the internal space; and a sealing body joined to the first resin portion, the outer surface of the first resin portion including: a first end surface in the first direction; a second end surface on the opposite side of the first end surface in the first direction; and four outer side surfaces extending in the first direction so as to connect the first end surface and the second end surface.

Description

Technical Field

[0001] The present disclosure relates to a power storage module. Background Art

[0002] Patent document 1 describes a bipolar secondary battery. The power generation element of the bipolar secondary battery has a plurality of bipolar electrodes, which form a positive electrode active material layer electrically coupled to one surface of the collector, and a negative electrode active material layer electrically coupled to the surface on the opposite side of the collector. The bipolar electrodes are stacked with an electrolyte layer between them to form the power generation element. Adjacent positive electrode active material layers, electrolyte layers, and negative electrode active material layers constitute a single cell layer. A sealing portion is arranged on the periphery of the single cell layer. The sealing portion is arranged between the collectors in the peripheral portion of the collector to prevent adjacent collectors from contacting each other.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 5504708 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] In order to improve the sealing performance of the sealing portion of the above-mentioned bipolar secondary battery, it is possible to consider adopting a structure in which a sealing body is assembled on the sealing portion of the outer side of the stacked body with electrodes. For example, in the case of assembling a sealing body around a connecting hole (liquid injection port) provided in the sealing portion to connect the inside and the outside of the bipolar secondary battery, the holding area around the liquid injection port of the sealing portion is configured for an injection molding mold or a heat sealer, etc., and the stacked body is pressurized in the stacking direction. In any of these cases, the sealing body can be stably assembled to the outer side of the stacked body by increasing the holding area.

[0008] An object of the present disclosure is to provide a power storage module in which a sealing body having improved sealing performance can be stably provided.

[0009] Solutions for solving problems

[0010] The storage module disclosed herein comprises: an electrode stack having a plurality of electrodes including a current collector and stacked along a first direction; a first resin portion, which is arranged on the electrode stack in a manner of forming an internal space between the current collectors adjacent in the first direction and sealing the internal space; and a sealing body, which is joined to the first resin portion, wherein the outer surface of the first resin portion comprises: a first end face in the first direction; a second end face on the side opposite to the first end face in the first direction; and four outer side faces, which extend along the first direction in a manner of connecting the first end face to the second end face, wherein the sealing body is joined to at least the first end face and the second end face, and the first resin portion comprises: a plurality of sealants, which are frame-shaped and are arranged at the peripheral edge of each of the plurality of current collectors; a plurality of spacers, which are frame-shaped and are interposed between the sealants adjacent in the first direction and are spaced between the current collectors together with the plurality of sealants. Forming an internal space; a welding end portion, which is formed by welding the outer peripheral edges of multiple seals and multiple spacers on the side opposite to the internal space, including four outer sides; and multiple connecting holes, which connect the internal space with the outside of the first resin part by opening the first outer side surface, which is one of the four outer sides, and the internal space. At least in the first part of the first resin part, in the area including the first outer side surface where the opening of the connecting hole is formed, when viewed from the first direction, the inner edge of the sealant is located inside of the outer edge of the collector, at least in the first part, when viewed from the first direction, the inner edge of the closing body is consistent with the inner edge of the sealant or is located outside of the inner edge of the sealant, and at least in the first part, when viewed from the first direction, at least a part of the inner edge of the spacer is located inside of the inner edge of the sealant.

[0011] In the power storage module, a first resin portion is provided for an electrode stack including electrodes stacked along a first direction, and a sealing body is joined to a first end face and a second end face in the first direction of the first resin portion. In the first resin portion, a spacer is interposed between sealants provided at the peripheral portion of the current collector of the electrode. Thus, an internal space is formed by the sealant and the spacer between the current collectors adjacent along the first direction. In addition, in the first resin portion, a plurality of connecting holes are formed that connect the first outer side surface of the four outer side surfaces of the first resin portion with the internal space. The connecting hole can be used, for example, as an injection port for injecting electrolyte into the internal space. Furthermore, in a first portion of the region of the first resin portion including the first outer side surface forming the opening of the connecting hole, when viewed from the first direction, at least a portion of the inner edge of the spacer is located at a position closer to the inside than the inner edge of the sealant. Therefore, when viewed from the first direction, at least in this portion, the spacer will exceed the inner edge of the sealant and be interposed there. Therefore, the mold or heat sealer for injection molding can be configured as the above-mentioned holding area, and the sealing body can be set by applying a pressing force / holding force. Therefore, the sealing body for improving the sealing property can be stably set.

[0012] In the storage battery module involved in the present disclosure, the four outer side surfaces may also include three second outer side surfaces that are different from the first outer side surfaces, and in the second part of the first resin part including each of the three second outer side surfaces, when viewed from the first direction, the inner edge of the spacer is located closer to the inside than the inner edge of the sealing member.

[0013] In the power storage module according to the present disclosure, the sealing body may include, in the first portion, an injected resin portion welded to the first end surface and the second end surface.

[0014] In the power storage module according to the present disclosure, the sealing body may include a laminate sheet including a metal layer and an insulating layer laminated on the metal layer, and the laminate sheet may be welded to the first end surface and the second end surface.

[0015] In the power storage module according to the present disclosure, the electrode stack may include a separator interposed between each of the plurality of electrodes adjacent to each other in the first direction, and an end of the separator may be arranged between the sealant and the spacer in the first direction.

[0016] Effects of the Invention

[0017] According to the present disclosure, it is possible to provide a power storage module in which a sealing body having improved sealing performance can be stably provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic plan view of the power storage module according to the present embodiment.

[0019] Figure 2 It is along Figure 1 Schematic cross-sectional view along line II-II.

[0020] Figure 3 It is along Figure 1 Schematic cross-sectional view along line III-III.

[0021] Figure 4 yes Figure 3 A schematic cross-sectional view of a portion of the power storage module shown.

[0022] Figure 5 It is shown Figure 1 Schematic diagram of a portion of the power storage module shown.

[0023] Figure 6 It is shown Figure 1 Schematic diagram of a portion of the power storage module shown.

[0024] Figure 7 It is shown Figure 2 , Figure 3A schematic cross-sectional view of a modified example of the spacer shown.

[0025] Figure 8 It is a schematic cross-sectional view of a power storage module according to a modification.

[0026] Fig. 9 It is a schematic cross-sectional view of a power storage module according to another modification. DETAILED DESCRIPTION

[0027] Hereinafter, one embodiment will be described with reference to the accompanying drawings. In the description of the accompanying drawings, the same or equivalent elements are marked with the same reference numerals, and repeated descriptions are sometimes omitted. Sometimes, an orthogonal coordinate system defined by a coordinate axis representing a first direction D1, a coordinate axis representing a second direction D2, and a coordinate axis representing a third direction D3 is shown.

[0028] Figure 1 It is a schematic plan view of the power storage module according to the present embodiment. Figure 2 It is along Figure 1 Schematic cross-sectional view along line II-II. Figure 3 It is along Figure 1 Schematic cross-sectional view along line III-III. Figure 4 yes Figure 3 A schematic cross-sectional view of a portion of the power storage module shown. Figure 1 to Figure 4 The power storage module 1 shown is, for example, a power storage module used in batteries of various vehicles such as forklifts, hybrid vehicles, and electric vehicles. The power storage module 1 is, for example, a secondary battery such as a nickel-hydrogen secondary battery or a lithium-ion secondary battery. The power storage module 1 may also be a double-layer capacitor or an all-solid-state battery. Here, the case where the power storage module 1 is a lithium-ion secondary battery is shown.

[0029] The power storage module 1 includes an electrode stack 10, a first resin portion 20, and a sealing body 50. Figure 1 , the sealing body 50 is omitted. The electrode stack 10 includes a plurality of electrodes stacked along a first direction D1. The first direction D1 is the stacking direction of the electrodes and is the height direction of the power storage module 1. The plurality of electrodes include a plurality of bipolar electrodes 11, a positive terminal electrode 12, and a negative terminal electrode 13. A separator 14 is interposed between adjacent electrodes.

[0030] The bipolar electrode 11 includes a current collector 15, a positive electrode active material layer 16, and a negative electrode active material layer 17. The current collector 15 is, for example, in the form of a rectangular sheet. The positive electrode active material layer 16 is provided on one surface 15a of the current collector 15. The negative electrode active material layer 17 is provided on the other surface 15b of the current collector 15. The plurality of bipolar electrodes 11 are stacked in such a manner that the positive electrode active material layer 16 of one bipolar electrode 11 faces the negative electrode active material layer 17 of another bipolar electrode 11. Here, one surface 15a of the current collector 15 is a surface facing one side of the first direction D1, and the other surface 15b of the current collector 15 is a surface facing the other side of the first direction D1.

[0031] The positive electrode active material layer 16 and the negative electrode active material layer 17 are rectangular when viewed from the first direction D1. The negative electrode active material layer 17 is slightly larger than the positive electrode active material layer 16 when viewed from the first direction D1. That is, when viewed from above from the first direction D1, the entire formation region of the positive electrode active material layer 16 is located within the formation region of the negative electrode active material layer 17.

[0032] The positive terminal electrode 12 has a current collector 15 and a positive electrode active material layer 16 provided on one surface 15a of the current collector 15. The positive terminal electrode 12 does not have the positive electrode active material layer 16 and the negative electrode active material layer 17 on the other surface 15b of the current collector 15. That is, no active material layer is provided on the other surface 15b of the current collector 15 of the positive terminal electrode 12. The positive terminal electrode 12 is stacked on the bipolar electrode 11 at the other end of the electrode stack 10 in the first direction D1. The positive terminal electrode 12 is stacked on the bipolar electrode 11 in such a manner that the positive electrode active material layer 16 thereof faces the negative electrode active material layer 17 of the bipolar electrode 11.

[0033] The negative terminal electrode 13 includes a current collector 15 and a negative active material layer 17 provided on the other surface 15b of the current collector 15. The negative terminal electrode 13 does not include a positive active material layer 16 and a negative active material layer 17 on one surface 15a of the current collector 15. That is, no active material layer is provided on one surface 15a of the current collector 15 of the negative terminal electrode 13. The negative terminal electrode 13 is stacked on the bipolar electrode 11 at one end portion of the electrode stack 10 in the first direction D1. The negative terminal electrode 13 is stacked on the bipolar electrode 11 in such a manner that its negative active material layer 17 faces the positive active material layer 16 of the bipolar electrode 11.

[0034] The separator 14 is arranged so as to be sandwiched between adjacent bipolar electrodes 11, between the positive terminal electrode 12 and the bipolar electrode 11, and between the negative terminal electrode 13 and the bipolar electrode 11. The separator 14 is interposed between the positive electrode active material layer 16 and the negative electrode active material layer 17. The separator 14 prevents a short circuit caused by contact between adjacent electrodes by isolating the positive electrode active material layer 16 from the negative electrode active material layer 17 and allows charge carriers such as lithium ions to pass through.

[0035] The current collector 15 is a chemically inert electrical conductor used to allow current to continue to flow through the positive electrode active material layer 16 and the negative electrode active material layer 17 during the discharge or charge period of the lithium ion secondary battery. The material of the current collector 15 is, for example, a metal material, a conductive resin material, or a conductive inorganic material. As the conductive resin material, for example, a conductive polymer material or a resin formed by adding a conductive filler to a non-conductive polymer material as needed can be listed. The current collector 15 can also have a plurality of layers. In this case, each layer of the current collector 15 can also contain the above-mentioned metal material or conductive resin material.

[0036] A coating layer may also be formed on the surface of the current collector 15. The coating layer may be formed by a known method such as plating or spraying. The current collector 15 may be, for example, in the form of a plate, a foil (such as a metal foil), a film, or a mesh. Examples of metal foils include aluminum foil, copper foil, nickel foil, titanium foil, or stainless steel foil. Examples of stainless steel foils include SUS 304, SUS 316, or SUS 301 specified in JIS G 4305:2015. By using stainless steel foil as the current collector 15, the mechanical strength of the current collector 15 can be ensured. The current collector 15 may also be an alloy foil or a clad foil of the above-mentioned metals. When the current collector 15 is in the form of a foil, the thickness of the current collector 15 may be, for example, 1 μm to 100 μm.

[0037] The positive electrode active material layer 16 contains a positive electrode active material that can absorb and release charge carriers such as lithium ions. Examples of the positive electrode active material include lithium composite metal oxides having a layered rock salt structure, metal oxides having a spinel structure, and polyanion compounds. The positive electrode active material can be any positive electrode active material that can be used in a lithium ion secondary battery. The positive electrode active material layer 16 may also contain a plurality of positive electrode active materials. In the present embodiment, the positive electrode active material layer 16 contains olivine-type lithium iron phosphate (LiFePO4) as a composite oxide.

[0038] The negative electrode active material layer 17 contains a negative electrode active material that can absorb and release charge carriers such as lithium ions. The negative electrode active material can be any one of a simple substance, an alloy or a compound. As the negative electrode active material, for example, lithium (Li), carbon, a metal compound, etc. can be listed. The negative electrode active material can also be an element or a compound thereof that can be alloyed with lithium. As carbon, for example, natural graphite, artificial graphite, hard carbon (difficult to graphitize carbon) or soft carbon (easy to graphitize carbon) can be listed. As artificial graphite, for example, highly oriented graphite, mesophase carbon microbeads, etc. can be listed. As elements that can be alloyed with lithium, silicon (silicon) or tin can be listed. In the present embodiment, the negative electrode active material layer 17 contains graphite as a carbon-based material.

[0039] The positive electrode active material layer 16 and the negative electrode active material layer 17 (hereinafter, sometimes referred to as "active material layer") may each contain a conductive aid for improving electrical conductivity, a binder, an electrolyte (polymer matrix, ion conductive polymer, electrolyte solution, etc.), an electrolyte supporting salt (lithium salt) for improving ion conductivity, etc. as needed. The conductive aid is added to improve the conductivity of each electrode (bipolar electrode 11, positive terminal electrode 12, negative terminal electrode 13). The conductive aid is, for example, acetylene black, carbon black, or graphite.

[0040] As the binder, there can be listed fluorine-containing resins such as polyvinylidene fluoride, polytetrafluoroethylene, fluorine rubber, thermoplastic resins such as polypropylene and polyethylene, imide resins such as polyimide and polyamide-imide, resins containing alkoxysilyl groups, acrylic resins such as acrylic acid or methacrylic acid, styrene-butadiene rubber (SBR), carboxymethyl cellulose, sodium alginate, alginates such as ammonium alginate, water-soluble cellulose ester crosslinked products, starch-acrylic acid graft polymers, etc. These binders can be used alone or in combination. For example, water, N-methyl-2-pyrrolidone (NMP), etc. are used as solvents.

[0041] The separator 14 can be, for example, a porous sheet or nonwoven fabric containing a polymer that absorbs and retains an electrolyte. Examples of the material of the separator 14 include polypropylene, polyethylene, polyolefin, polyester, and the like. The separator 14 can have a single-layer structure or a multi-layer structure. The multi-layer structure can have, for example, an adhesive layer or a ceramic layer as a heat-resistant layer. The separator 14 can also be impregnated with an electrolyte. The separator 14 can also be composed of an electrolyte such as a polymer electrolyte or an inorganic electrolyte. Examples of the electrolyte impregnated into the separator 14 include a liquid electrolyte (electrolyte) containing a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent, or a polymer gel electrolyte containing an electrolyte retained in a polymer matrix.

[0042] When the separator 14 is impregnated with an electrolyte, known lithium salts such as LiClO4, LiAsF6, LiPF6, LiBF4, LiCF3SO3, LiN(FSO2)2, and LiN(CF3SO2)2 can be used as the electrolyte salt. In addition, known solvents such as cyclic carbonates, cyclic esters, chain carbonates, chain esters, and ethers can be used as the non-aqueous solvent. In addition, two or more of these known solvent materials can also be used in combination.

[0043] The first resin portion 20 is formed in a frame shape at the peripheral portion of the electrode stack 10 in a manner surrounding the electrode stack 10. The first resin portion 20 can be joined to each of one surface 15a and another surface 15b of the collector 15 in the peripheral portion 15c of each collector 15. The first resin portion 20 is used to form an internal space S between the collectors 15 adjacent in the first direction D1 and to close each of the internal spaces S. An electrolyte (not shown) is contained in each internal space S. That is, the first resin portion 20, together with the collectors 15 adjacent in the first direction D1, defines an internal space S for containing the electrolyte. The first resin portion 20 prevents the electrolyte from penetrating to the outside.

[0044] The first resin portion 20 suppresses the intrusion of moisture and the like from the outside of the electrode stack 10 into the internal space S. For example, in order to suppress the inflow of the atmosphere from the outside of the electrode stack 10 into the internal space S, the first resin portion 20 may also adjust the diffusion coefficient or the permeability coefficient so that the atmosphere is difficult to penetrate through the resin. The edge of the separator 14 is bonded to the first resin portion 20. The first resin portion 20 includes an insulating material. As the material of the first resin portion 20, various resin materials such as polypropylene, polyethylene, polystyrene, ABS resin, acid-modified polypropylene, acid-modified polyethylene, and acrylonitrile styrene resin can be listed.

[0045] The first resin portion 20 includes a plurality of seals 21, a plurality of spacers 22, and a welded end portion 23. The seal 21 is provided on each current collector 15. Thus, the seals 21 are stacked one on another along the first direction D1. The seal 21 is frame-shaped when viewed from the first direction D1, and is provided on the peripheral portion 15c of the current collector 15. The seal 21 is provided in a manner that extends from one face 15a of the current collector 15 through the end face to the other face 15b, and covers the peripheral portion 15c. The seal 21 is welded to two faces, one face 15a and the other face 15b of the current collector 15. More specifically, one seal 21 is frame-shaped when viewed from the first direction, and is composed of a pair of substrates provided in a manner that clamps the peripheral portion 15c of the current collector 15. One of the pair of substrates is arranged in the peripheral portion 15c of the current collector 15 in a manner that extends from one face 15a of the current collector 15 beyond the end face and is welded to one face 15a. The other of the pair of substrates is arranged in the peripheral portion 15c of the current collector 15 so as to extend beyond the end surface from the other surface 15b of the current collector 15 and is welded to the other surface 15b. Furthermore, the pair of substrates are overlapped with each other in the portion beyond the end surface of the current collector 15, and are partially welded as described later to form a welded end portion 23.

[0046] The spacer 22 is arranged so as to be interposed between the seals 21 adjacent in the first direction D1. Thus, the spacer 22 maintains the space between the adjacent seals 21, that is, between the adjacent current collectors 15. The spacer 22 is frame-shaped when viewed from the first direction D1, and is arranged on the peripheral edge 15c of the current collector 15. The spacer 22 is in contact with a pair of seals 21 adjacent in the first direction D1.

[0047] The welded end portion 23 is formed by welding the ends (outer peripheries) of the plurality of seals 21 and the plurality of spacers 22 on the side opposite to the internal space S to each other and integrating them. In other words, the seals 21 and the spacers 22 are arranged to be in contact with each other without being welded in the portion other than the welded end portion 23. The welded end portion 23 is frame-shaped in a manner surrounding the electrode stack 10 when viewed from the first direction D1. The side surface of the welded end portion 23 on the side opposite to the internal space S extends along the first direction D1, constituting the outer side surface 20s of the first resin portion 20. In other words, the first resin portion 20 includes the outer side surface 20s on the side opposite to the internal space S.

[0048] The first resin portion 20 has a communication hole 27 (see Figure 1 , Figure 4). As an example, the connecting hole 27 is formed by penetrating the spacer 22 and the welded end portion 23. The connecting hole 27 has one opening in the internal space S and another opening 27h on the outer side surface 20s of the first resin portion 20. In the power storage module 1, a cell C including one internal space S is formed between a pair of adjacent collectors 15. Here, one connecting hole 27 is formed for one cell C.

[0049] Therefore, the outer side surface 20s of the first resin portion 20 includes a first outer side surface 20sA on which an opening 27h of the connecting hole 27 is formed, and the other three second outer side surfaces 20sB, 20sC, and 20sD. The second outer side surface 20sB is a surface on the opposite side of the first outer side surface 20sA, and the second outer side surface 20sC and the second outer side surface 20sD are surfaces connecting the first outer side surface 20sA and the second outer side surface 20sB. In addition, both ends of the first resin portion 20 in the first direction D1 are respectively formed by the sealing member 21. Therefore, the first end surface 20a and the second end surface 20b of the first resin portion 20 in the first direction D1 are set as the outer surfaces of a pair of sealing members 21 arranged at both ends of the first resin portion 20 in the first direction D1.

[0050] Thus, the outer surface of the first resin portion 20 includes: a first end surface 20a in the first direction D1; a second end surface 20b on the opposite side of the first end surface 20a in the first direction D1; and four outer side surfaces 20s extending along the first direction D1 in a manner connecting the first end surface 20a and the second end surface 20b. The four outer side surfaces 20s are the outer surfaces of the welded end portion 23. A plurality of openings 27h of the communicating holes 27 are formed on the first outer side surface 20sA, which is one of the four outer side surfaces 20s. The three second outer side surfaces 20sB, 20sC, and 20sD, which are different from the first outer side surface 20sA among the four outer side surfaces 20s, are not provided with the openings 27h of the communicating holes 27.

[0051] Here, Figure 5 and Figure 6 It is shown Figure 1 Schematic diagram of a portion of the power storage module shown. Figure 5 (a) is Figure 1 An enlarged top view of region R1, Figure 5 (b) is along Figure 1 An enlarged cross-sectional view of the Vb-Vb line. Figure 6 (a) is Figure 1 An enlarged top view of region R2, Figure 6 (b) is along Figure 1 An enlarged cross-sectional view of line VIb-VIb. Figure 2 , Figure 3 , Figure 5 , Figure 6 The shown enclosing body 50 is in a rectangular frame shape when viewed from the first direction D1, and is disposed on the first end face 20a, the second end face 20b, and the outer side face 20s of the first resin portion 20. The enclosing body 50 is joined (welded) to each of the first end face 20a and the second end face 20b and the outer side face 20s. The enclosing body 50 includes a laminate sheet 30 and a second resin portion (injection resin portion) 40. However, the enclosing body 50 may not be in a frame shape.

[0052] The laminate sheet 30 is in a rectangular frame shape when viewed from the first direction D1, and is provided on the second outer side surfaces 20sB, 20sC, 20sD, the first end surface 20a, and the second end surface 20b among the outer side surfaces 20s of the first resin portion 20. The laminate sheet 30 includes: a metal layer 30a; a first insulating layer 30b, which is laminated on the metal layer 30a; and a second insulating layer 30c, which is laminated on the opposite side of the first insulating layer 30b to the metal layer 30a. The laminate sheet 30 is fused to the first resin portion 20 in the first insulating layer 30b.

[0053] The first insulating layer 30b is made of an insulating resin. The material of the first insulating layer 30b is, for example, polypropylene, polyethylene, polyamide, etc. From the perspective of adhesion to the first resin portion 20, the material of the first insulating layer 30b can be selected from the same type of material as the first resin portion 20. The metal layer 30a is made of a material with low moisture permeability (small moisture permeability coefficient) such as aluminum foil or stainless steel foil. The second insulating layer 30c is, for example, made of an insulating resin. The material of the second insulating layer 30c is, for example, polypropylene, nylon, etc. As an example, the laminate 30 is an aluminum laminate, polypropylene can be selected as the first insulating layer 30b, aluminum can be selected as the metal layer 30a, and polyethylene terephthalate can be selected as the second insulating layer 30c.

[0054] The laminated sheet 30 is fused to at least the first end face 20a and the second end face 20b, and is also fused to the second outer side faces 20sB, 20sC, and 20sD. The laminated sheet 30 includes: a pair of end face portions 31, which are arranged on the first end face 20a and the second end face 20b, respectively; and side face portions 32, which are arranged on the second outer side faces 20sB, 20sC, and 20sD.

[0055] In this way, the laminate sheet 30 helps to suppress the permeation of moisture and gas between the internal space S and the outside of the battery module 1 (and improve the pressure resistance) in the first direction D1 and the second direction D2 and the third direction D3 intersecting the first direction D1, by covering at least a portion of the first end face 20a and the second end face 20b of the first resin portion 20 in the first direction D1, and substantially the entire second outer side faces 20sB, 20sC, and 20sD, that is, helps to improve the sealing performance.

[0056] The second resin portion 40 is in a rectangular frame shape when viewed from a third direction D3 intersecting the first direction D1, and is provided on the first outer side surface 20sA, the first end surface 20a, and the second end surface 20b among the outer side surfaces 20s of the first resin portion 20. The second resin portion 40 is at least fused to the first end surface 20a and the second end surface 20b, and is also fused to the first outer side surface 20sA. More specifically, the second resin portion 40 can be provided on the first end surface 20a, the second end surface 20b, and the first outer side surface 20sA by injection molding.

[0057] The second resin portion 40 includes a reinforcing portion 41 and a frame portion 42. As described later, a rectangular frame-shaped frame portion 42 is formed on the first outer side surface 20sA where the opening 27h of the communicating hole 27 is formed so as to surround the opening 27h when viewed from the third direction D3. The frame portion 42 is protruded from the base portion 40p on the first outer side surface 20sA of the second resin portion 40 in the third direction D3. The base portion 40p is a plate-shaped portion welded to the first outer side surface 20sA. Thus, in the first outer side surface 20sA, the welded end portion 23 and the base portion 40p are stacked along the third direction D3.

[0058] The reinforcement part 41 is provided on each of the first end face 20a and the second end face 20b. More specifically, the reinforcement part 41 is provided from the seal 21 to the welded end 23. The reinforcement part 41 is provided on the first end face 20a and the second end face 20b to increase the thickness of the resin part in the first direction D1, that is, the distance from the internal space S to the outside of the storage module 1 in the first direction D1, which helps to suppress the water permeation and gas permeation between the internal space S and the outside along the first direction D1 (and improve the pressure resistance), that is, helps to improve the sealing performance.

[0059] In addition, in the third direction D3 intersecting the first direction D1, a base portion 40p as a resin portion corresponding to the reinforcing portion 41 is provided for the first outer side surface 20sA of the first resin portion 20. Since the thickness of the resin portion (sealant 21 or spacer 22 and welded end portion 23) excluding the second resin portion 40 in the third direction D3, that is, the distance from the internal space S to the outside of the storage module 1 in the third direction D3 excluding the second resin portion 40 is larger than that in the first direction D1, moisture permeation and gas permeation are less likely to occur than in the first direction D1. In addition, by providing the base portion 40p and providing the sealing film 45 described later on the frame portion 42, moisture permeation and gas permeation in the third direction D3 can be further suppressed.

[0060] As described above, the frame 42 is provided on the first outer side surface 20sA (via the base 40p) in a rectangular frame shape surrounding the openings 27h of each of the plurality of communication holes 27 when viewed from the third direction D3 intersecting the first outer side surface 20sA. The base 40p has through holes provided at positions corresponding to the communication holes 27, whereby the openings 27h of the communication holes 27 are connected to the region 43 surrounded by the frame 42. As an example, the frame 42 is used when the electrolyte is injected into each of the internal spaces S.

[0061] More specifically, when injecting the electrolyte, the nozzle of the electrolyte injection device is brought into close contact with the top surface of the frame 42, and the electrolyte is introduced into each area 43 from the nozzle. In this way, the electrolyte can be injected into the internal space S from the connecting hole 27 connected to each area 43 via the opening 27h. A closing film 45 is attached to the frame 42. The closing film 45 can be set to the same layer structure and material as the laminated sheet 30, for example. Thus, the connecting hole 27 and the internal space S are closed. In this way, in addition to the function of being a sealing body 50, the second resin part 40 can also have the function of injecting the electrolyte and closing the internal space S. That is, the second resin part 40 is also an injection frame here.

[0062] Next, the positional relationship of each part of the power storage module 1 will be described. Figure 1 As shown, the first resin portion 20 is in a rectangular ring shape when viewed from the first direction D1, and is composed of parts corresponding to the four sides of the rectangle. One of the parts corresponding to the four sides is a first part 20A including a region of the first outer side surface 20sA where the opening 27h of the communication hole 27 is formed. The parts corresponding to the other three sides of the parts corresponding to the four sides are a second part 20B including the second outer side surface 20sB, a second part 20C including the second outer side surface 20sC, and a second part 20D including the second outer side surface 20sD.

[0063] In addition, here, among the four outer side surfaces 20s of the first resin portion 20, the outer side surface 20s where the opening 27h of the communicating hole 27 is formed is referred to as the "first outer side surface", and the other parts are referred to as the "second outer side surface". In addition, among the parts of the first resin portion 20, the part including the periphery of the opening 27h of the communicating hole 27 of the "first outer side surface" when viewed from the first direction D1 is referred to as the "first part", and the other parts are referred to as the "second part".

[0064] Similarly, the spacer 22 is in a rectangular ring shape when viewed from the first direction D1, and is composed of four first side portions 22A to 22D corresponding to the four sides of the rectangle. When viewed from the first direction D1, the first side portion 22A is a portion included in the first portion 20A of the first resin portion 20, the first side portion 22B is a portion included in the second portion 20B of the first resin portion 20, the first side portion 22C is a portion included in the second portion 20C of the first resin portion 20, and the first side portion 22D is a portion included in the second portion 20D of the first resin portion 20.

[0065] exist Figure 5 , a portion of the second portion 20D including the first resin portion 20 of the power storage module 1 is shown. Figure 5 The positional relationship among the current collector 15, the seal 21, the spacer 22 (ie, the first side portion 22D), and the laminate sheet 30 will be described. Figure 5 As shown, when viewed from the first direction D1, the inner edge 21e of the seal 21 is located on the inner side (i.e., the inner space S side) than the outer edge 15e of the collector 15. In addition, when viewed from the first direction D1, the inner edge 30e of the (end surface portion 31) of the laminate sheet 30 is located on the inner side than the outer edge 15e of the collector 15, and is substantially consistent with the inner edge 21e of the seal 21.

[0066] Furthermore, when viewed from the first direction D1, the inner edge 22e of the spacer 22 (first side portion 22D) is located inwardly of the inner edge 21e of the seal 21. Thus, the spacer 22 includes a protrusion 22p that protrudes inwardly from the inner edge 21e of the seal 21 when viewed from the first direction D1. That is, when viewed from the first direction D1, the entire region where the seal 21 is provided becomes a region (holding region) where the seal 21 and the spacer 22 overlap.

[0067] Therefore, when the laminated sheet 30 is welded to the seal 21, the entire seal 21 (the entire first end face 20a and the second end face 20b) can be pressed in the first direction D1 by the sealer SD, thereby ensuring a welding margin for the laminated sheet 30. In addition, the end of the spacer 14 is overlapped with the protruding portion 20p and welded to the spacer 22.

[0068] Although in Figure 5 Although not shown in the figure, the same positional relationship also exists for the portions of the power storage module 1 corresponding to the second portions 20B and 20C of the first resin portion 20 .

[0069] exist Figure 6 , a portion of the first portion 20A including the first resin portion 20 of the power storage module 1 is shown. Figure 6The same description is given for the positional relationship among the current collector 15, the sealing member 21, the spacer 22 (ie, the first side portion 22A), and the second resin portion 40. Figure 6 As shown, here, when viewed from the first direction D1, the inner edge 21e of the seal 21 is also located inward (i.e., on the inner space S side) than the outer edge 15e of the collector 15. In addition, when viewed from the first direction D1, the inner edge 40e of the second resin portion 40 (reinforcement portion 41) is located inward than the outer edge 15e of the collector 15 and outward than the inner edge 21e of the seal 21.

[0070] Furthermore, when viewed from the first direction D1, the inner edge 22e of the spacer 22 (first side portion 22A) is located at a position closer to the inside than the inner edge 21e of the seal 21. Thus, the spacer 22 includes a protrusion 22p that protrudes inward from the inner edge 21e of the seal 21 when viewed from the first direction D1. Furthermore, the end of the spacer 14 is overlapped with the protrusion 20p and fused to the spacer 22. That is, when viewed from the first direction D1, the entire region where the seal 21 is provided becomes a region where the seal 21 and the spacer 22 overlap.

[0071] Therefore, when the second resin portion 40 is formed on the first resin portion 20 by injection molding, the edge of the mold MD can be arranged to be directly above (directly below) the inner edge 21e of the seal 21 and held along the first direction D1, thereby ensuring the formation area of ​​the second resin portion 40 (reinforcement portion 41). In addition, here, the end of the spacer 14 is also overlapped with the protrusion 20p and welded to the spacer 22.

[0072] In the case of forming the second resin part 40 by injection molding, first, the mold MD is assembled on the stack including the electrode stack 10 and the first resin part 20. Then, the second resin part 40 is formed by injecting resin into the molding space of the mold MD assembled on the stack. As an example, when the mold MD is assembled, the region (holding region) where multiple collectors 15, multiple seals 21, and multiple spacers 22 overlap when viewed from the first direction D1 can be clamped (held) by the mold MD. In this case, in the holding region, a space where the spacer 22 does not exist in the stacking direction is not formed. Therefore, stable clamping can be performed by the mold MD (the second resin part 40 can be stably formed). In addition, in the case of setting the end face 31 of the laminated sheet 30 on the first end face 20a and the second end face 20b to be formed as the second resin part 40 (reinforcement part 41), the end face 31 can be set before the second resin part 40 is formed by injection molding, or the end face 31 can be set after the second resin part 40 is formed by injection molding.

[0073] As described above, in the power storage module 1, in all the first side portions 22A to 22D of the spacer 22, the inner edge 22e is located inside the inner edge 21e of the seal 21, and includes the protrusion 22p. In addition, in the power storage module 1, the second resin portion 40 is provided only in the first portion 20A of the first portion 20A and the second portion 20B to 20D of the first resin portion 20. In addition, in the power storage module 1, the laminate sheet 30 is provided in the second portion 20B to 20D of the first resin portion 20. In addition, in the present embodiment, the end face portion 31 of the laminate sheet 30 is provided on the first end face 20a and the second end face 20b of the first portion 20A. In the first portion 20A, the end face portion 31 only needs to be arranged and bonded to the portion of the first end face 20a and the second end face 20b that is exposed from the reinforcing portion 41 of the second resin portion 40. In other words, the end surface portion 31 can be set to the first end surface 20a and / or the second end surface 20b before injection molding of the second resin portion 40, so that at least a portion of the end surface portion 31 is further configured between the first end surface 20a and / or the second end surface 20b and the reinforcement portion 41.

[0074] Furthermore, a conductive member 60 that functions as a terminal for extracting current from the power storage module 1 is disposed and electrically connected to a portion of one surface 15a of the current collector 15 of the positive terminal electrode 12 and the other surface 15b of the current collector 15 of the negative terminal electrode 13 that is exposed from the first resin portion 20. The conductive member 60 can be used to electrically connect a plurality of power storage modules 1. In addition, the conductive member 60 can also be used as a restraining member to add a restraining load to the electrode stack 10. Furthermore, a cooling flow path can also be formed in the conductive member 60. By allowing a cooling medium to flow through the cooling flow path formed in the conductive member 60, the electrode stack 10 can be cooled.

[0075] However, in order to form an internal space between adjacent current collectors, a spacer is sometimes placed between adjacent sealing portions that are assembled to each current collector and face each other in the stacking direction. In this case, from the perspective of ensuring the capacity of the internal space, it can be considered to adopt a configuration in which the inner edge of the spacer is located at a position closer to the outside than the inner edge of the sealing portion (i.e., a portion of the spacer is recessed).

[0076] On the other hand, a sealing body is sometimes provided on the outside of the sealing part for various purposes such as suppressing water permeation between the internal space and the outside, suppressing gas permeation, or improving pressure resistance. In this case, the sealing property can be improved by: arranging a sheet-like sealing body on the sealing part, applying pressure to the sealing body in the stacking direction while inputting heat through a sealing machine so that the sealing body is welded to the sealing part; or arranging a mold in a manner to hold the sealing part along the stacking direction, and forming the sealing body by injection molding using the mold.

[0077] In any of these cases, the pressing force / holding force cannot be applied to the area where the seal is provided and the spacer is not between the seals (the area inside the inner edge of the spacer), and sometimes it becomes difficult to install the sealing body. In such a situation, it is preferable to expand the area where the sealing body is provided as much as possible for the entire area where the sealing body is provided, so that the sealing body is provided larger and more stably.

[0078] In the power storage module 1 according to the present embodiment, the first resin part 20 is provided for the electrode stack 10 including the electrodes (the bipolar electrode 11, the positive terminal electrode 12, and the negative terminal electrode 13) stacked along the first direction D1, and the sealing body 50 is joined to the first end face 20a and the second end face 20b of the first resin part 20 in the first direction D1. In the first resin part 20, the spacer 22 is interposed between the sealants 21 provided on the peripheral portion 15c of the current collector 15 of the electrode. Thus, the internal space S is formed by the sealant 21 and the spacer 22 between the current collectors 15 adjacent to each other along the first direction D1. In addition, in the first resin part 20, a plurality of communication holes 27 are formed to connect the first outer side surface 20sA among the four outer side surfaces 20s of the first resin part 20 with the internal space S. The communication holes 27 can be used as a liquid injection port for injecting an electrolyte into the internal space S, for example.

[0079] Furthermore, in the first portion 20A of the first resin portion 20 including the first outer side surface 20sA in the region forming the opening 27h of the communicating hole 27, at least a portion (here, the entire portion) of the inner edge 22e of the spacer 22 is located inwardly relative to the inner edge 21e of the sealing member 21 when viewed from the first direction. Therefore, when viewed from the first direction D1, at least in this portion, the spacer 22 will exceed the inner edge 21e of the sealing member 21 and be located there. Therefore, this portion can be used as a holding area, and the mold MD or heat sealer for injection molding or the like can be configured as described above, and the closing body 50 can be set by applying a pressing force / holding force. Therefore, the closing body 50 for improving the sealing performance can be stably set.

[0080] In the power storage module 1, the sealing body 50 includes the second resin portion 40 welded to the first end face 20a and the second end face 20b in the first portion 20A. Therefore, by configuring the mold MD for injection molding as described above with the inner edge 22e of the spacer 22 located inside the inner edge 21e of the seal 21 as the holding region, the second resin portion 40 as the injection resin portion can be stably provided.

[0081] In the power storage module 1, the sealing body 50 includes a laminated sheet 30 including a metal layer 30a and a first insulating layer 30b laminated on the metal layer 30a, and the laminated sheet 30 is welded to the first end face 20a and the second end face 20b of the first resin portion 20 in the first insulating layer 30b. Therefore, the laminated sheet 30 can appropriately suppress the permeation of moisture or gas in the internal space S or improve the strength.

[0082] Furthermore, in the power storage module 1, the electrode stack 10 includes a separator 14 interposed between each of the plurality of electrodes adjacent to each other in the first direction D1, and the separator 22 includes a protrusion 22p protruding inward from the inner edge 21e of the seal 21 when viewed from the first direction D1. In addition, the end of the separator 14 is overlapped and fused to the protrusion 22p. Therefore, if the melting point of the separator 22 is relatively increased, short circuits between the collectors 15 will not occur as long as the melting point of the separator 22 is not exceeded, and heat resistance is improved.

[0083] Furthermore, in the storage battery module according to the present disclosure, the four outer side surfaces may include three second outer side surfaces that are different from the first outer side surfaces, and in the second portion of the first resin portion including each of the three second outer side surfaces, when viewed from the first direction, the inner edge of the spacer is located inside the inner edge of the sealant. In this case, in the second portion of the second outer side surface other than the first outer side surface including the opening formed with the communicating hole, by making the inner edge of the spacer located inside the inner edge of the sealant, a pressing force / holding force can be applied to set the sealing body.

[0084] In the storage battery module of the present disclosure, the sealing body may include an injection resin portion welded to the first end face and the second end face in the first portion. In this case, the first portion including the portion where the inner edge of the spacer is located inside the inner edge of the sealant becomes a holding area. By configuring the mold for injection molding in the holding area as described above, the sealing body including the injection resin portion can be stably set.

[0085] In the storage battery module of the present disclosure, the sealing body may include a laminated sheet, the laminated sheet includes a metal layer and an insulating layer laminated on the metal layer, and the laminated sheet is welded to the first end face and the second end face. In this case, the laminated sheet including the metal layer can appropriately suppress the water permeation or gas permeation in the internal space or improve the strength.

[0086] In the battery module of the present disclosure, the electrode stack may include a separator between each of a plurality of electrodes adjacent to each other in the first direction, and the end of the separator may be arranged between the seal and the separator in the first direction. In this case, if the melting point of the separator is relatively increased, short circuits between the current collectors will not occur as long as the melting point of the separator is not exceeded, and heat resistance is improved.

[0087] The above embodiment is an embodiment for explaining one aspect of the power storage module according to the present disclosure. Therefore, the power storage module according to the present disclosure can be an power storage module obtained by arbitrarily modifying the above-mentioned power storage module 1 .

[0088] For example, Figure 7 As shown in (a), the spacer 22 may also have a multilayer structure. As an example, the spacer 22 may include: an intermediate layer 221; a pair of outermost layers 222 stacked on both sides of the intermediate layer 221; and a pair of adhesive layers 223 between the intermediate layer 221 and each outermost layer 222. The intermediate layer 221 may be made of a material having excellent heat resistance and gas permeability (such as PP, etc.), and the outermost layer 222 may be made of a material having excellent compatibility with the material of the seal 21 (such as low-density PE) (such as a mixed material of PE and PP, etc.). In addition, the adhesive layer 223 is a layer that bonds the intermediate layer 221 to the outermost layer 222, and is provided as needed (that is, it may be omitted).

[0089] Likewise, if Figure 7 As shown in (b), the seal 21 may also have a multi-layer structure. Figure 7 In the example (b), a pair of substrates 21a constituting one sealing member 21 are each configured as a multilayer structure. In this example, each substrate 21a includes: an intermediate layer 211; a pair of outermost layers 212 stacked on both sides of the intermediate layer 211; and a pair of adhesive layers 213 interposed between the intermediate layer 211 and each outermost layer 212. The intermediate layer 211, the outermost layer 212, and the adhesive layer 213 may be formed by Figure 7 The intermediate layer 221, the outermost layer 222 and the adhesive layer 223 shown in (a) are made of the same material. Figure 7 In the figure, hatching of various parts is omitted.

[0090] In addition, in the power storage module 1, since the end of the metal layer 30a may be exposed at the end (inner edge 30e) of the laminate sheet 30, an insulator (not shown) may be provided in a manner covering the end of the laminate sheet 30. In this case, as an example of the insulator, an insulating film attached from one surface 15a and / or the other surface 15b of the collector 15 to the end of the laminate sheet 30 can be provided. In this case, the insulation of the laminate sheet 30 is achieved. As a result, the positive terminal electrode 12 and the negative terminal electrode 13 of the electrode stack 10 are prevented from short-circuiting via the metal layer 30a of the laminate sheet 30.

[0091] In the above embodiment, an example is described in which the entire inner edge 22e of the spacer 22 is located inside the inner edge 21e of the seal 21 when viewed from the first direction D1. However, in the power storage module 1, at least a portion (for example, at least one side portion) of the inner edge 22e of the spacer 22 is only required to be located inside the inner edge 21e of the seal 21.

[0092] That is, Figure 8 As shown, in the power storage module 1, in the second portion 20B including the second outer side surface 20sB of the first resin portion 20, the inner edge 22e of the spacer 22 may be located at a position further outward than the inner edge 21e of the sealant 21 when viewed from the first direction D1. That is, in the power storage module 1, at least in the first portion 20A including the region of the first outer side surface 20sA of the first resin portion 20 where the opening 27h of the communication hole 27 is formed, at least a portion of the inner edge 22e of the spacer 22 may be located at a position further inward than the inner edge 21e of the sealant 21 when viewed from the first direction D1.

[0093] Therefore, the same is true for the second portions 20C and 20D including each of the other second outer side surfaces 20sC and 20sD of the first resin portion 20, and the inner edge 22e of the spacer 22 can be located outside the inner edge 21e of the sealing member 21. In this case, in the second portions 20B, 20C, and 20D of the second outer side surfaces 20sB, 20sC, and 20sD other than the first outer side surface 20sA of the first resin portion 20 including the opening 27h of the communication hole 27, by locating the inner edge 22e of the spacer 22 outside the inner edge 21e of the sealing member 21, the volume of the internal space S can be ensured to be large.

[0094] about Figure 8In other words, in the storage battery module 1, when viewed from the first direction D1, the inner edge 22e of the second side portion (first side portions 22B to 22D) other than the first side portion 22A among the multiple side portions of the spacer 22 is located outside the inner edge 21e of the seal 21. In this case, it is possible to stably set the sealing body 50 on the first side portion 22A, and to ensure a large volume of the internal space S in the first side portions 22B to 22D. In addition, here, among the multiple side portions of the spacer 22, the side portion whose inner edge is located inside the inner edge 21e of the seal 21 is referred to as the "first side portion", and the other side portions are referred to as the "second side portion".

[0095] In this case, the end surface portion 31 of the laminate sheet 30 can be pressed and welded to the first resin portion 20 provided on the peripheral portion 15c of the current collector 15 by a sealing machine SD before the electrodes are stacked to form the electrode stack 10. In this case, the end surface portion 31 is provided before the second resin portion 40 is formed by injection molding, but the end surface portion 31 may be provided after the second resin portion 40 is formed by injection molding.

[0096] In addition, if Figure 8 As shown, in the power storage module 1 , the spacer 14 may extend to reach between the seal 21 and the spacer 22 . In this case, the peripheral edge of the spacer 14 is sandwiched between the seal 21 and the spacer 22 and welded to the first resin portion 20 .

[0097] Furthermore, the portion of the first resin portion 20 corresponding to the first outer side surface 20sA may include: a first portion including a region of the first outer side surface 20sA where the opening 27h of the communication hole 27 is formed; and a second portion other than the first portion, in which the inner edge 22e of the spacer 22 is located outside the inner edge 21e of the sealing member 21. In this case, the inner edge 22e of the spacer 22 is located inside the inner edge 21e of the sealing member 21 only within the minimum required range, so that the internal space S can be ensured to be large.

[0098] Fig. 9 FIG. 2 is a schematic cross-sectional view of a power storage module according to another modification. Fig. 9 In the example, Figure 8 In the example shown, the spacer 14 extends to reach between the seal 21 and the spacer 22. Thus, the end of the spacer 14 is arranged between the seal 21 and the spacer 22 in the first direction D1. Also in this example, the peripheral edge of the spacer 14 is sandwiched between the seal 21 and the spacer 22 and welded to the first resin portion 20.

[0099] In addition, if Fig. 9 As shown, in the storage battery module 1, the portion of the first resin portion 20 corresponding to the first outer side surface 20sA may include: the first portion 20A including the region of the first outer side surface 20sA where the opening 27h of the communication hole 27 is formed; and the second portions 20B to 20D other than the first portion 20A, wherein the inner edge 22e of the spacer 22 is located inwardly of the inner edge 21e of the sealing member 21 in all of the second portions 20B to 20D (all sides of the first resin portion 20). In this case, the sealing body 50 can be provided by applying a pressing force / holding force.

[0100] Here, in the above embodiment, the case where the sealing body 50 is a rectangular ring when viewed from the first direction D1 is described, but the sealing body 50 may not be a ring when viewed from the first direction D1. In this case, the sealing body 50 only needs to be provided in at least one of the portions (the first portion 20A and the second portions 20B to 20D) corresponding to the four sides of the first resin portion 20. Furthermore, the sealing body 50 may be provided only in a portion of the portion corresponding to one side of the first resin portion 20.

[0101] In the above embodiment, the laminated sheet 30 including the metal layer 30a is exemplified. However, the laminated sheet 30 may include a resin layer instead of the metal layer 30a. The material of the resin layer may be polypropylene, polyethylene, polyamide, polyimide, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, etc.

[0102] Description of Reference Numerals

[0103] 1…power storage module; 10…electrode stack; 15…collector; 15e…outer edge; 20…first resin portion; 20A…first part; 20B, 20C, 20D…second part; 20a…first end face; 20b…second end face; 20s…outer side face; 20sA…first outer side face; 20sB, 20sC, 20sD…second outer side face; 21…seal; 21e, 22e, 30e, 40e…inner edge; 22…spacer; 22p…protrusion; 22A…first side portion; 22B, 22C, 22D…first side portion; 27…connecting hole; 27h…opening; 30…laminated sheet; 30a…metal layer; 30b…first insulating layer (insulating layer); 40…second resin portion (injected resin portion); S…internal space.

Claims

1. A power storage module, characterized in that: have: an electrode stack having a plurality of electrodes including a current collector and stacked along a first direction; a first resin portion provided on the electrode stack so as to form an internal space between the current collectors adjacent to each other in the first direction and to seal the internal space; and a sealing body joined to the first resin portion, The outer surface of the first resin portion comprises: a first end surface in the first direction; A second end surface on the side opposite to the first end surface in the first direction; and 4 outer side surfaces extending along the first direction in a manner connecting the first end surface and the second end surface, The closing body is at least joined to the first end surface and the second end surface, The first resin portion includes: A plurality of seals, which are frame-shaped and are disposed at the peripheral edge of each of the plurality of current collectors; a plurality of spacers in a frame shape, interposed between the seals adjacent to each other in the first direction, and forming the internal space between the current collectors together with the plurality of seals; a welded end portion formed by welding the outer peripheral edges of the plurality of seal members and the plurality of spacers on the side opposite to the internal space, and including the four outer side surfaces; and a plurality of communication holes which communicate the internal space with the outside of the first resin portion by opening at a first external side surface which is one of the four external side surfaces and the internal space, At least in a first portion of the first resin portion including a region of the first outer side surface where the opening of the communicating hole is formed, an inner edge of the sealant is located inside the outer edge of the collector when viewed from the first direction, At least in the first portion, when viewed from the first direction, the inner edge of the closing body is consistent with the inner edge of the sealing member or is located outside the inner edge of the sealing member. At least in the first portion, at least a portion of an inner edge of the spacer is located inside of an inner edge of the seal when viewed from the first direction.

2. The power storage module according to claim 1, wherein: The four outer side surfaces include three second outer side surfaces that are outer side surfaces different from the first outer side surfaces, In the second portion of the first resin portion including each of the three second outer side surfaces, an inner edge of the spacer is located inside of an inner edge of the sealing member when viewed from the first direction.

3. The power storage module according to claim 1 or 2, wherein: The closing body includes, in the first portion, an injected resin portion welded to the first end surface and the second end surface.

4. The power storage module according to any one of claims 1 to 3, wherein: The enclosed body comprises a laminated sheet, wherein the laminated sheet comprises a metal layer and an insulating layer laminated on the metal layer. The laminate is welded to the first end surface and the second end surface.

5. The power storage module according to any one of claims 1 to 4, wherein: The electrode stack includes a separator between each of the plurality of electrodes adjacent to each other in the first direction. An end portion of the spacer is disposed between the seal member and the spacer in the first direction.

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