Energy storage module and method for manufacturing an energy storage module

Abstract

To provide a power storage module that can suppress increase in a size of molds required for manufacturing.SOLUTION: A power storage module includes an electrode laminate, a sealing body provided on the electrode laminate, and an injection resin portion joined to the sealing body, each of a plurality of electrodes includes a current collector having a rectangular shape when viewed from a first direction. The sealing body includes a welded end portion in which outer peripheral edges of a plurality of frame-like members are welded to each other, and a plurality of communication holes that communicates with an outside of a liquid injection port surface at the welded end. The injection resin portion includes a main body portion that partially covers the liquid injection port surface, and when viewed from a second direction intersecting the liquid injection port surface, and a plurality of protruding frame portions surrounding openings respectively connected to the plurality of communication holes.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to a power storage module and a method for manufacturing the same.

Background Art

[0002] Patent Document 1 discloses a power storage module. This power storage module includes an electrode laminate and a frame provided so as to surround the electrode laminate over the entire circumference when viewed in the stacking direction. The electrode laminate includes a plurality of electrode plates stacked via separators. The frame has through holes penetrating to the internal space formed between adjacent electrode plates. The through holes function as injection ports for injecting an electrolytic solution into the internal space. Such a frame is, for example, an injection resin body formed by injection molding.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the configuration in which an injection port is provided in an injection resin body that surrounds the electrode laminate over the entire circumference as described above, when manufacturing a power storage device having a large-area electrode, it is conceivable that the size of the power storage module increases. Also, in this case, the size of the required mold also increases, which may lead to an increase in production costs.

[0005] The present disclosure provides a power storage module and a method for manufacturing the same that can suppress an increase in the size of the power storage module and the size of the mold required for manufacturing.

Means for Solving the Problems

[0006] An energy storage module according to one aspect of the present disclosure comprises an electrode stack including a plurality of electrodes stacked along a first direction, forming internal spaces between adjacent electrodes, and including a sealant provided to seal the internal spaces, and an injection-molded resin portion joined to the sealant. Each of the plurality of electrodes includes a current collector that is rectangular in shape when viewed from the first direction. The sealant includes a welded end where the outer edges of a plurality of frame-shaped members, which are interposed between the plurality of current collectors and stacked in the first direction, are welded to each other. The sealant has a first end face and a second end face which are both end faces of the electrode stack in the first direction, a liquid injection port face which is one of the four outer surfaces constituting the circumferential surface of the welded end and to which the injection-molded resin portion is joined, and a plurality of communication holes which connect the outside of the liquid injection port face to each of the plurality of internal spaces. The injection-molded resin part includes a main body that partially covers the liquid injection port surface and has multiple openings connected to multiple communication holes, a first overhang part connected to the main body that partially covers the first end surface, and a second overhang part connected to the main body that partially covers the second end surface. The main body includes multiple protruding frame parts that project in a second direction intersecting the liquid injection port surface, and the multiple protruding frame parts surround each of the multiple openings when viewed from the second direction.

[0007] In the above-described energy storage module, a communication hole is provided at the welded end of the sealing body formed on the outer edge of the electrode stack, penetrating to the internal space. An injection-molded resin part having a frame surrounding the communication hole is joined to the sealing body. This injection-molded resin part has a main body that covers the liquid injection port surface, which is one of the four outer surfaces forming the welded end, a first overhang extending from the main body to the first end surface of the electrode stack, and a second overhang extending from the main body to the second end surface of the electrode stack. In this way, since the injection-molded resin part is provided on only one of the four outer surfaces, an increase in the size of the energy storage module is suppressed. Furthermore, the injection-molded resin part does not require a mold that surrounds the entire circumference of the electrode stack, but can be formed with a mold that is sized to partially cover the liquid injection port surface. Therefore, an increase in the size of the mold required for manufacturing can be suppressed.

[0008] One example of an injection-molded resin part is a first thin-walled part connected to the main body, having a first thin-walled part that is joined to the injection port surface along the injection port surface from the main body, and the thickness of the first thin-walled part in the second direction may be smaller than the thickness of the main body in the second direction. In this configuration, the injection-molded resin part can be more firmly bonded to the sealant formed on the outer edge of the electrode laminate.

[0009] One example of an injection-molded resin portion is a second thin-walled portion connected to a first overhang portion, having the second thin-walled portion joined to the first end face along the first end face from the first overhang portion, and the thickness of the second thin-walled portion in the first direction may be smaller than the thickness of the first overhang portion in the first direction. In this configuration, the injection-molded resin portion can be more firmly bonded to the sealant formed on the outer edge of the electrode laminate.

[0010] One example of a current collector has a first region where an active material layer is formed, located in the center of the current collector when viewed from a first direction, and a frame-shaped second region outside the first region. The frame-shaped member may include a plurality of frame-shaped sealing materials provided in the second region of each of the plurality of current collectors, and a plurality of spacers interposed between adjacent sealing materials in the first direction, which together with the plurality of sealing materials define an internal space between the current collectors. In this configuration, the outer edges of the sealing materials and the outer edges of the spacers are welded to each other to form a welded end.

[0011] A method for manufacturing an energy storage module according to one aspect of the present disclosure comprises the steps of: preparing an electrode stack including a plurality of electrodes stacked along a first direction, with both end faces in the first direction being the first and second end faces; providing welded ends to the electrode stack such that an internal space is formed between adjacent electrodes; and providing injection resin parts to the welded ends. Each of the plurality of electrodes includes a current collector that is rectangular in shape when viewed from the first direction. The step of providing welded ends includes welding the outer edges of a plurality of frame-shaped members that are interposed between the plurality of current collectors and stacked in the first direction to each other. The liquid injection port surface, which is one of the four outer surfaces of the welded end opposite to the internal space, has a plurality of communication holes that communicate with each of the plurality of internal spaces. The step of providing the injection resin portion includes the steps of attaching a mold that partially covers the injection port surface to the electrode stack such that a continuous molding space is formed between a main body region including a plurality of communication holes on the injection port surface, a first overhang region connected to the main body region and partially extending to the first end face of the electrode stack, and a second overhang region connected to the main body region and partially extending to the second end face of the electrode stack; and injecting resin into the molding space of the mold attached to the electrode stack.

[0012] In the above-described method for manufacturing energy storage modules, an energy storage module is manufactured in which a communication hole penetrating to the internal space is provided at the welded end of a sealing body formed on the outer edge of the electrode stack. An injection-molded resin part having a frame surrounding the communication hole is joined to the sealing body. In the step of attaching the mold to the electrode stack, the mold is attached such that a molding space is formed between the main body region extending to the liquid injection port surface, which is one of the four outer surfaces forming the welded end, the first overhang region extending from the main body to the first end surface of the electrode stack, and the second overhang region extending from the main body to the second end surface of the electrode stack. In this case, a mold large enough to surround the entire circumference of the electrode stack is not required, and the injection-molded resin part can be formed with a mold large enough to partially cover one outer surface of the electrode stack. Therefore, it is possible to suppress an increase in the size of the mold required for manufacturing. In addition, it is possible to suppress an increase in the size of the manufactured energy storage module.

[0013] In one example, the process of installing the mold connects to the molding space, forming a first thin-walled space that extends from the molding space along the injection port surface, and the thickness of the first thin-walled space in a second direction intersecting the injection port surface may be smaller than the thickness of the molding space in the main body region in the second direction. This configuration can mitigate the pressure rise within the molding space during injection molding.

[0014] In one example, the process of installing the mold connects to the molding space and forms a second thin-walled space extending from the first overhang region along the first end face, and the thickness of the second thin-walled space in the first direction may be smaller than the thickness of the molding space in the first overhang region in the first direction. This configuration can mitigate the pressure rise in the molding space during injection molding.

[0015] The current collector has a first region where an active material layer is formed, located in the center of the current collector when viewed from a first direction, and a frame-shaped second region outside the first region. The frame-shaped member includes a plurality of frame-shaped sealing materials provided in the second region of each of the plurality of current collectors, and a plurality of spacers interposed between adjacent sealing materials in the first direction, which together with the plurality of sealing materials define an internal space between the current collectors. The electrode laminate includes a plurality of separators arranged between the plurality of current collectors, each of which has its outer edge positioned between the plurality of sealing materials and the plurality of spacers. The step of attaching the mold may involve clamping the region of the electrode laminate where the plurality of current collectors, the plurality of sealing materials, the plurality of spacers, and the plurality of separators overlap when viewed from a first direction. In this configuration, a region of uniform thickness in which the current collectors, sealing materials, spacers, and separators are laminated is clamped by the mold, so the electrode laminate can be stably clamped by the mold.

[0016] One mold example includes a first mold and a second mold that sandwich the electrode laminate from the first direction. The surface roughness of the surface of the first mold that contacts the electrode laminate and the surface of the second mold that contacts the electrode laminate may be greater than the surface roughness of the forming surface of the molding space in the mold. In this configuration, the friction coefficient between the first mold, the second mold, and the electrode laminate can be increased. Therefore, even with a small clamping force, it is possible to suppress the displacement of the electrode laminate.

Advantages of the Invention

[0017] According to the present disclosure, it is possible to provide a power storage module and a method for manufacturing the same that can suppress an increase in the size of the mold and the power storage module required for manufacturing.

Brief Description of the Drawings

[0018] [Figure 1] FIG. 1 is a schematic plan view of an example of a power storage module. [Figure 2] FIG. 2 is a schematic cross-sectional view of an example of a power storage module. [Figure 3] FIG. 3 is a schematic front view of an example of a power storage module. [Figure 4] FIG. 4 is a schematic cross-sectional view of an example of a power storage module. <着 [Figure 5] FIG. 5 is a schematic cross-sectional view of an example of a power storage module. [Figure 6] FIG. 6 is a schematic cross-sectional view of an example of a power storage module. [Figure 7] FIG. 7 is a flow showing an example of a method for manufacturing a power storage module. [Figure 8] FIG. 8 is a plan view showing the position of a mold attached to an example of a power storage module. [Figure 9] FIG. 9 is a schematic cross-sectional view of an example of a mold. [Figure 10] FIG. 10 is a schematic cross-sectional view of an example of a mold. [Figure 11] FIG. 11 is a schematic cross-sectional view of an example of a mold. [Figure 12]FIG. 12 is a diagram showing the contact surface of the mold with respect to the electrode laminate. [Figure 13] FIG. 13 is a schematic plan view of a power storage module of another example. [Figure 14] FIG. 14 is a schematic cross-sectional view of the power storage module shown in FIG. 13. [Figure 15] FIG. 15 is a schematic cross-sectional view of the mold shown in FIG. 13. [Figure 16] FIG. 16 is a schematic plan view of a power storage module of yet another example. [Figure 17] FIG. 17 is a schematic cross-sectional view of the mold shown in FIG. 16. [Figure 18] FIG. 18 is a schematic cross-sectional view of a power storage module of yet another example. [Figure 19] FIG. 19 is a diagram showing another example of the contact surface of the mold with respect to the electrode laminate.

MODE FOR CARRYING OUT THE INVENTION

[0019] Hereinafter, an embodiment will be described with reference to the drawings. In the description of the drawings, the same or equivalent elements may be denoted by the same reference numerals, and redundant descriptions may be omitted. Further, in the description, an orthogonal coordinate system defined by the X-axis, Y-axis, and Z-axis shown in the drawings may be referred to.

[0020] FIG. 1 is a schematic plan view of a power storage module according to the present embodiment. The power storage module 1 is, for example, a power storage module used for the battery 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 be an electric double layer capacitor or a all-solid-state battery. Here, the case where the power storage module 1 is a lithium-ion secondary battery is shown.

[0021] The energy storage module 1 comprises an electrode stack 10 and an injection-molded resin part 50. The electrode stack 10 has a rectangular shape when viewed from the Z-axis direction (first direction) and has four outer surfaces 20s. The injection-molded resin part 50 is bonded to one of the four outer surfaces 20s, outer surface 20sA (the liquid injection port surface). Of the other three outer surfaces 20sB, 20sC, and 20sD, outer surface 20sB is the surface opposite outer surface 20sA, and outer surfaces 20sC and 20sD are surfaces that connect outer surface 20sA and outer surface 20sB. In the illustrated example, when viewed from the Z-axis direction, outer surfaces 20sA and 20sB constitute the short sides, and outer surfaces 20sC and 20sD constitute the long sides. For example, the energy storage module may have a rectangular shape with dimensions of approximately 300mm x 700mm to 1300mm x 2000mm when viewed from the Z-axis direction.

[0022] Figure 2 is a cross-sectional view along the line II-II in Figure 1, showing the vicinity of the outer surface 20sD. The vicinity of the outer surfaces 20sB and 20sC also has a similar cross-section to Figure 2. Figure 3 is a front view of the injection-molded resin part 50, partially showing the outer surface 20sA. Figure 4 is a cross-section along the line IV-IV in Figure 3, Figure 5 is a cross-section along the line VV in Figure 3, and Figure 6 is a cross-section along the line VI-VI in Figure 3.

[0023] The electrode stack 10 includes a plurality of electrodes stacked along the Z-axis direction. The Z-axis direction is the direction in which the electrodes are stacked, and is the height direction of the energy 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. Separators 14 are interposed between adjacent electrodes.

[0024] The bipolar electrode 11 comprises a current collector 15, a positive electrode active material layer 16, and a negative electrode active material layer 17. The current collector 15 is rectangular in shape when viewed from the Z-axis direction and is in the form of a sheet. The current collector 15 has a first region R1 in the center of the current collector 15 when viewed from the Z-axis direction, where the active material layers (positive electrode active material layer 16, negative electrode active material layer 17) are formed, and a frame-shaped second region R2 outside the first region R1. The positive electrode active material layer 16 is provided on one side 15a of the current collector 15. The negative electrode active material layer 17 is provided on the other side 15b of the current collector 15. Multiple bipolar electrodes 11 are stacked so that the positive electrode active material layer 16 of one adjacent bipolar electrode 11 and the negative electrode active material layer 17 of the other bipolar electrode 11 face each other in the stacking direction. Here, one side 15a of the current collector 15 is a surface facing one direction in the Z-axis direction, and the other side 15b of the current collector 15 is a surface facing the other direction in the Z-axis direction.

[0025] The positive electrode active material layer 16 and the negative electrode active material layer 17 are rectangular when viewed from the Z-axis direction. The negative electrode active material layer 17 is slightly larger than the positive electrode active material layer 16 when viewed from the Z-axis direction. In a plan view from the Z-axis direction, 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.

[0026] The positive terminal electrode 12 comprises a current collector 15 and a positive electrode active material layer 16 provided on one side 15a of the current collector 15. The positive terminal electrode 12 does not have a positive electrode active material layer 16 or a negative electrode active material layer 17 on the other side 15b of the current collector 15. In other words, no active material layer is provided on the other side 15b of the current collector 15 of the positive terminal electrode 12. The positive terminal electrode 12 is laminated on the bipolar electrode 11 at the other end of the electrode laminate 10 in the Z-axis direction. The positive terminal electrode 12 is laminated on the bipolar electrode 11 such that its positive electrode active material layer 16 faces the negative electrode active material layer 17 of the bipolar electrode 11.

[0027] The negative electrode terminal electrode 13 comprises a current collector 15 and a negative electrode active material layer 17 provided on the other side 15b of the current collector 15. The negative electrode terminal electrode 13 does not have a positive electrode active material layer 16 or a negative electrode active material layer 17 on one side 15a of the current collector 15. In other words, there is no active material layer on one side 15a of the current collector 15 of the negative electrode terminal electrode 13. The negative electrode terminal electrode 13 is laminated on the bipolar electrode 11 at one end of the electrode laminate 10 in the Z-axis direction. The negative electrode terminal electrode 13 is laminated on the bipolar electrode 11 such that its negative electrode active material layer 17 faces the positive electrode active material layer 16 of the bipolar electrode 11.

[0028] The separator 14 is positioned 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, separating them. The separator 14 prevents short circuits caused by contact between adjacent electrodes while allowing charge carriers such as lithium ions to pass through.

[0029] The current collector 15 is a chemically inert electrical conductor that allows current to continue flowing through the positive electrode active material layer 16 and the negative electrode active material layer 17 during the discharge or charging 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. Examples of conductive resin materials include conductive polymer materials or resins to which conductive fillers are optionally added to non-conductive polymer materials. The current collector 15 may comprise multiple layers. In this case, each layer of the current collector 15 may contain the above-mentioned metal material or conductive resin material.

[0030] A coating layer may be formed on the surface of the current collector 15. This coating layer may be formed by known methods such as plating or spray coating. The current collector 15 may be in the form of a plate, foil (e.g., metal foil), film, or 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 as 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 clad foil of the above metals. When the current collector 15 is in the form of foil, the thickness of the current collector 15 may be, for example, 1 μm to 100 μm.

[0031] The positive electrode active material layer 16 contains a positive electrode active material capable of intercalating and releasing charge carriers such as lithium ions. Examples of positive electrode active materials include lithium composite metal oxides having a layered rock salt structure, metal oxides having a spinel structure, and polyanionic compounds. The positive electrode active material can be any material suitable for use in lithium-ion secondary batteries. The positive electrode active material layer 16 may contain multiple positive electrode active materials. In this embodiment, the positive electrode active material layer 16 contains olivine-type lithium iron phosphate (LiFePO4) as a composite oxide.

[0032] The negative electrode active material layer 17 contains a negative electrode active material capable of intercalating and releasing charge carriers such as lithium ions. The negative electrode active material may be an element, an alloy, or a compound. Examples of negative electrode active materials include Li, carbon, and metal compounds. The negative electrode active material may also be an element or compound thereof that can be alloyed with lithium. Examples of carbon include natural graphite, artificial graphite, hard carbon (carbon that is difficult to graphitize), or soft carbon (carbon that is easily graphitized). Examples of artificial graphite include highly oriented graphite and mesocarbon microbeads. Examples of elements that can be alloyed with lithium include silicon or tin. In this embodiment, the negative electrode active material layer 17 contains graphite as a carbon-based material.

[0033] Each of the positive electrode active material layer 16 and the negative electrode active material layer 17 (hereinafter sometimes simply referred to as the "active material layer") may further contain, as necessary, conductive additives, binders, electrolytes (polymer matrix, ion-conducting polymer, electrolyte solution, etc.), electrolyte-supporting salts (lithium salts) to enhance ionic conductivity, etc. Conductive additives are added to enhance the conductivity of each electrode (bipolar electrode 11, positive electrode terminal electrode 12, negative electrode terminal electrode 13). Examples of conductive additives include acetylene black, carbon black, or graphite.

[0034] Examples of binders include fluororesins such as polyvinylidene fluoride, polytetrafluoroethylene, and fluororubber; thermoplastic resins such as polypropylene and polyethylene; imide resins such as polyimide and polyamideimide; alkoxysilyl group-containing resins; acrylic resins such as acrylic acid or methacrylic acid; styrene-butadiene rubber (SBR); alginates such as carboxymethylcellulose, sodium alginate, and ammonium alginate; water-soluble cellulose ester crosslinked polymers; and starch-acrylic acid graft polymers. These binders can be used individually or in combination. Examples of solvents include water and N-methyl-2-pyrrolidone (NMP).

[0035] The separator 14 may be, for example, a porous sheet or nonwoven fabric containing a polymer that absorbs and retains electrolytes. Examples of materials for the separator 14 include polypropylene, polyethylene, polyolefin, and polyester. The separator 14 may have a single-layer structure or a multilayer structure. The multilayer structure may include, for example, a ceramic layer as an adhesive layer or a heat-resistant layer. The separator 14 may be impregnated with an electrolyte. The separator 14 may be composed of an electrolyte such as a polymer electrolyte or an inorganic electrolyte. Examples of electrolytes impregnated into the separator 14 include a liquid electrolyte (electrolyte solution) containing a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent, or a polymer gel electrolyte containing an electrolyte held in a polymer matrix.

[0036] 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 may be used as the electrolyte salt. Furthermore, known solvents such as cyclic carbonates, cyclic esters, linear carbonates, linear esters, and ethers may be used as the non-aqueous solvent. Two or more of these known solvent materials may be used in combination.

[0037] The electrode stack 10 further includes a sealant 20. The sealant 20 is formed in a frame shape on the periphery of the electrode stack 10 so as to form the outer edge of the electrode stack 10 when viewed from the Z-axis direction. The sealant 20 can be joined to one surface 15a and the other surface 15b of each current collector 15 at the periphery 15c of each current collector 15. The sealant 20 forms an internal space S between adjacent current collectors 15 in the Z-axis direction and seals each of these internal spaces S. Each internal space S contains an electrolyte (not shown). That is, the sealant 20 cooperates with adjacent current collectors 15 in the Z-axis direction to define an internal space S that contains the electrolyte. The sealant 20 prevents the electrolyte from permeating to the outside.

[0038] The sealant 20 prevents moisture and other substances from entering the internal space S from the outside of the electrode stack 10. The sealant 20 prevents gases generated at each electrode, such as during charge-discharge reactions, from leaking to the outside of the energy storage module 1. The edges of the separator 14 are joined to the sealant 20. The sealant 20 contains an insulating material. Examples of materials for the sealant 20 include various resin materials such as polypropylene, polyethylene, polystyrene, ABS resin, acid-modified polypropylene, acid-modified polyethylene, and acrylonitrile styrene resin.

[0039] An example of a sealing body 20 includes a plurality of sealing materials 21, a pair of end sealing materials 24, and a plurality of spacers 22. The sealing materials 21, end sealing materials 24, and spacers 22 may be frame-shaped members formed in a sheet-like manner. The sealing body 20 also has a welded end 23. The plurality of sealing materials 21 are each provided in the second region R2 of the current collector 15 that constitutes a plurality of bipolar electrodes 11. The sealing material 21 is frame-shaped when viewed from the Z-axis direction and is provided along the peripheral edge 15c of the current collector 15. The peripheral edge 15c is the outer periphery of the second region R2. The sealing material 21 is provided so as to extend from one surface 15a of the current collector 15 through the end surface to the other surface 15b, and covers the peripheral edge 15c. The sealing material 21 can be welded to at least one of the one surface 15a and the other surface 15b of the current collector 15.

[0040] The end seal material 24 is provided in the second region R2 of the current collector 15 that constitutes the positive terminal electrode 12 and the negative terminal electrode 13. Therefore, the end seal material 24 is arranged to sandwich the multiple seal materials 21 from the Z-axis direction. The end seal material 24 is frame-shaped when viewed from the Z-axis direction and, like the seal material 21, is provided along the peripheral edge 15c of the current collector 15. For example, when viewed from the Z direction, the width of the seal material 21 in the region along the outer surface 20sA is wider than the width of the seal material 21 in the regions along the outer surfaces 20sB, 20sC, and 20sD. Also, when viewed from the Z-axis direction, the width of the end seal material 24 is wider than that of the seal material 21. That is, the inner edge of the end seal material 24 is located inside the inner edge of the seal material 21. Note that the width of the seal material 21 in the regions along the outer surfaces 20sA and 20sB may be the distance of the seal material 21 in the Y-axis direction (second direction) in that region. Furthermore, the width of the sealing material 21 in the region along the outer surfaces 20sC and 20sD may be the distance of the sealing material 21 in the X-axis direction (third direction) in that region.

[0041] The spacer 22 has a frame shape when viewed from the Z-axis direction and is arranged along the peripheral edge 15c of the current collector 15. The spacer 22 is positioned to be interposed between adjacent sealing materials 21 in the Z-axis direction. The spacer 22 can be welded to at least one of a pair of adjacent sealing materials 21 in the Z-axis direction. Alternatively, the spacer 22 can be positioned to be interposed between adjacent sealing materials 21 and end sealing materials 24 in the Z-axis direction. The spacer 22 can be welded to at least one of adjacent sealing materials 21 and end sealing materials 24 in the Z-axis direction. The spacer 22 can maintain space between adjacent current collectors 15 in the Z-axis direction. That is, the spacer 22, sealing materials 21 and end sealing materials 24 define an internal space S between adjacent current collectors 15.

[0042] When viewed from the Z direction, the width of the spacer 22 in the region along the outer surface 20sA is wider than the width of the spacer 22 in the regions along the outer surfaces 20sB, 20sC, and 20sD. Also, in the regions along the outer surfaces 20sB, 20sC, and 20sD, the width of the spacer 22 is narrower than the width of the sealant 21. That is, in the regions along the outer surfaces 20sB, 20sC, and 20sD, the inner edge of the spacer 22 is located outside the inner edge of the sealant 21. On the other hand, in the region along the outer surface 20sA, the width of the spacer 22 is wider than the sealant 21. That is, in the region along the outer surface 20sA, the inner edge of the spacer 22 is located inside the inner edge of the sealant 21. In all regions, the inner edge of the spacer 22 is located outside the inner edge of the end sealant 24.

[0043] The welded end 23 is formed by welding together and integrating the ends of multiple sealing materials 21, a pair of end sealing materials 24, and multiple spacers 22 that are opposite to the internal space S. When viewed from the Z-axis direction, the welded end 23 has a frame-like shape that forms the outer circumference of the electrode stack 10. The side of the welded end 23 opposite to the internal space S extends along the Z-axis direction and constitutes the outer surface 20s of the sealant 20. In other words, the sealant 20 includes the outer surface 20s opposite to the internal space S. The outer surface 20s may be formed as a flat surface.

[0044] The sealing body 20 has a plurality of communication holes 27 that communicate with each of the plurality of internal spaces S (see Figure 5). For example, the communication holes 27 are notched portions formed in the spacer 22 and are formed to penetrate the welded end 23. The communication holes 27 have one opening in the internal space S and the other opening in the outer surface 20s of the sealing body 20. In the illustrated example, the opening is formed in the outer surface 20sA.

[0045] The injection-molded resin portion 50 is a reinforcing member that reinforces the outer surface 20sA in which the communication hole 27 is formed. The injection-molded resin portion 50 is molded into a predetermined shape to provide an injection port that communicates with the communication hole 27. The injection-molded resin portion 50 is joined to the sealant 20. For example, the injection-molded resin portion 50 is integrally joined to the sealant 20 by injection molding. An example of the injection-molded resin portion 50 includes a main body portion 51, a first overhang portion 55, a second overhang portion 57, and a first thin-walled portion 59.

[0046] The main body portion 51 partially covers the outer surface 20sA. For example, the main body portion 51 covers the outer surface 20sA such that it includes a region (main body region) R3 in which a plurality of communication holes 27 formed on the outer surface 20sA are formed. As described above, the plurality of communication holes 27 each communicate with a plurality of internal spaces S. In the example shown in Figure 3, the 30 communication holes 27 corresponding to the 30 layers of internal space formed between each current collector 15 are arranged discretely in the X-axis direction and the Z-axis direction. More specifically, the communication holes 27 corresponding to the 1st to 10th layers of internal space are arranged evenly spaced along the X-axis direction, with the positive terminal electrode 12 side as the base end, while the communication holes 27 corresponding to the 11th to 20th layers of internal space and the communication holes 27 corresponding to the 21st to 30th layers of internal space are arranged sequentially in the Z-axis direction below the 1st to 10th layers of internal space. The main body portion 51 extends in a rectangular shape along the X-axis and Z-axis directions in order to cover the main body region R3 in which these 30 communication holes 27 are formed.

[0047] The main body portion 51 is formed in the shape of a rectangular plate with a predetermined thickness in the Y-axis direction. For example, the thickness L2 of the main body portion 51 in the Y-axis direction may be 2.0 ± 0.5 mm. The main body portion 51 has an opening 52 at a position corresponding to the communication hole 27. The thickness L2 of the main body portion 51 corresponds to the depth of the opening 52 in the Y-axis direction provided in the main body portion 51. The main body portion 51 also has a protruding frame portion 53. The protruding frame portion 53 surrounds each opening 52 when viewed from the Y-axis direction (see Figure 3) and functions as a partition wall separating each opening 52. In the illustrated example, 10 protruding frame portions 53 are arranged in the X-axis direction, each having three spaces to separate three vertically aligned openings 52. For example, the thickness of the protruding frame portion 53 in the Y-axis direction may be approximately 0.5 mm to 6.0 mm.

[0048] The protruding frame portion 53 is used, for example, when injecting electrolyte into each of the internal spaces S. For example, when injecting electrolyte, the nozzle of the injection device is brought into close contact with the top surface of the protruding frame portion 53, and the electrolyte is introduced into the space of each protruding frame portion 53 from the nozzle. This makes it possible to inject electrolyte into the internal space S from the opening 52 and the communication hole 27.

[0049] After the electrolyte is injected, a laminate sheet 54 may be provided on the protruding frame portion 53 to seal it (see Figure 5). The laminate sheet 54 may be a sheet in which a metal layer, such as aluminum, is covered with a resin layer. The laminate sheet 54 may be fused to the top surface of the protruding frame portion 53, for example.

[0050] As shown in Figure 4, both end faces in the Z-axis direction of the electrode stack 10 are composed of a first end face 10a and a second end face 10b. The first overhang portion 55 is formed by connecting to the first end edge 51a in the Z-axis direction of the main body portion 51. The first overhang portion 55 partially covers the first end face 10a of the electrode stack 10. For example, the first overhang portion 55 partially covers the end seal material 24 joined to the positive terminal electrode 12 that constitutes the first end face 10a. In the illustrated example, the end edge 55a of the first overhang portion 55 extends from a position inside the outer edge 14a of the separator 14, as viewed from the Z-axis direction, to a position outside the inner edge 22a of the spacer 22. The first overhang portion 55 may be formed in the shape of a rectangular plate having the same length as the main body portion 51 in the X-axis direction. For example, the thickness of the first overhang portion 55 in the Z-axis direction may be 1.5 ± 0.5 mm, or it may be thinner.

[0051] The second overhang portion 57 connects to the second end edge 51b of the main body portion 51, opposite to the first end edge 51a, and partially covers the second end face 10b of the electrode laminate 10. For example, the second overhang portion 57 partially covers the end seal material 24 joined to the negative electrode terminal electrode 13 that constitutes the second end face 10b. In the illustrated example, the end edge 57a of the second overhang portion 57 extends from a position inside the outer edge 14a of the separator 14, as viewed from the Z-axis direction, to a position outside the inner edge 22a of the spacer 22. The second overhang portion 57 may be formed in the shape of a rectangular plate having the same length as the main body portion 51 in the X-axis direction. For example, the thickness of the second overhang portion 57 in the Z-axis direction may be 1.5 ± 0.5 mm, and may differ from the thickness of the first overhang portion 55.

[0052] The first thin-walled portion 59 is formed by connecting to the third end edge 51c and the fourth end edge 51d, which are the X-axis edges of the main body portion 51, respectively (see Figure 3). The first thin-walled portion 59 extends from the main body portion 51 along the outer surface 20sA and is joined to the outer surface 20sA. The size of the first thin-walled portion 59 in the Z-axis direction may be the same as the size of the main body portion 51 in the Z-axis direction. The thickness L1 of the first thin-walled portion 59 in the Y-axis direction (see Figure 6) is smaller than the thickness L2 of the main body portion 51 in the Y-axis direction (see Figure 4). The thickness L1 of the first thin-walled portion 59 may be 1 / 3 or less of the thickness L2 of the main body portion 51. For example, the thickness of the first thin-walled portion 59 in the Y-axis direction may be 0.5 mm or less. In the example shown in Figure 3, the first thin-walled portion 59 appears rectangular when viewed from the Y-axis direction. However, the first thin-walled portion 59 only needs to have a region that joins to the outer surface 20sA, and its shape is not limited to a rectangular shape.

[0053] Conductive members that function as terminals for drawing current from the energy storage module 1 may be placed on the exposed portions of the current collector 15a of the positive terminal electrode 12 and the other exposed portion of the current collector 15b of the negative terminal electrode 13, and electrically connected. Conductive members can be used to electrically connect multiple energy storage modules 1. Conductive members can also be used as restraining members to apply a restraining load to the electrode stack 10. Furthermore, cooling channels may be formed in the conductive members. The electrode stack 10 can be cooled by circulating a cooling medium through the cooling channels formed in the conductive members.

[0054] Next, a method for manufacturing an energy storage module will be described. Figure 7 is a flowchart showing an example of a method for manufacturing an energy storage module. In this example manufacturing method, first, an electrode stack 10 including a plurality of electrodes stacked along the Z-axis is formed (step S1). This prepares the electrode stack 10. Note that at step S1, the sealing body 20 of the formed electrode stack 10 does not have a welded end 23. That is, the end sealing material 24, sealing material 21 and spacer 22 stacked along the Z-axis are not welded to each other.

[0055] Furthermore, the spacer 22 may have a notched portion that connects from the internal space S to the outer edge at a position corresponding to the communication hole 27. In step S1, the electrode stack 10 is formed with the inserts placed in the notched portion formed in the spacer 22. The electrode stack 10 formed in this way has a plurality of inserts that protrude from the side corresponding to the outer surface 20sA. The inserts, being inserted into the notched portion, prevent the notched portion from being blocked in subsequent processes. After injection molding, the inserts are removed, forming the communication hole 27 and the opening 52 in the portion where the inserts were placed. The inserts may be, for example, metal plates.

[0056] Next, a welded end 23 is formed on the electrode stack 10 (step S2). This creates an internal space S between adjacent current collectors 15. The process of forming the welded end 23 involves welding the outer edges of the sealing material 21, end sealing material 24, and spacer 22 that constitute the electrode stack 10 to each other, on the side opposite to the internal space S. The welded end 23 is formed while the insert is still positioned in the notched portion of the spacer 22. In one example, the thickness of the welded end 23 corresponding to the other outer surfaces 20sB, 20sC, and 20sD may be greater than the thickness of the welded end 23 corresponding to the outer surface 20sA.

[0057] Next, an injection resin portion 50 is formed on the encapsulant 20 of the electrode laminate 10 (step S3). The step of forming the injection resin portion 50 includes the steps of attaching a mold that partially covers the outer surface 20sA to the electrode laminate 10 and injecting resin into the molding space of the mold. Figure 8 is a plan view showing the position of a mold 70 attached to an example of an energy storage module. In Figure 8, the mounting position of the mold 70 is indicated by a dashed line. Figure 9 is a schematic cross-sectional view showing the mold at the position of line IX-IX in Figure 8. Figure 10 is a schematic cross-sectional view showing the mold at the position of line XX in Figure 8. Figure 11 is a schematic cross-sectional view showing the mold at the position of line XI-XI in Figure 8.

[0058] In step S3, the mold 70 is attached to the electrode stack 10 placed on the mounting table, thereby forming a continuous molding space C between the main body region R3, the first overhang region R4, and the second overhang region R5 of the electrode stack 10 (see Figure 9). The thickness of the molding space C in the Y-axis direction corresponds to the thickness L2 of the main body portion 51 (see Figure 4). The thickness of the molding space C in the Z-axis direction may be controlled to be constant. This allows for the accurate and stable manufacturing of the energy storage module 1. If there is a tolerance in the size of the electrode stack 10, the volume of the molding space C may vary, for example, according to the thickness of the electrode stack 10 in the Z-axis direction placed in the mold 70. In this case, the thicknesses of the first overhang portion 55 and the second overhang portion 57 may be different.

[0059] The main body region R3 is a region that includes multiple communication holes 27 on the outer surface 20sA and is the bonding surface with the main body portion 51. The first overhang region R4 is a region that connects to the first edge R3a in the Z-axis direction of the main body region R3 and partially extends to the first end face 10a that intersects in the Z-axis direction of the electrode stack 10 and is the bonding surface with the first overhang portion 55. The second overhang region R5 is a region that connects to the second edge R3b on the opposite side of the first edge R3a of the main body region R3 and partially extends to the second end face 10b on the opposite side of the first end face 10a of the electrode stack 10 and is the bonding surface with the second overhang portion 57.

[0060] Furthermore, when the mold 70 is attached to the electrode laminate 10, a first thin-walled space SS1 is formed extending from the molding space C along the outer surface 20sA (see Figure 10). The thickness of the first thin-walled space SS1 in the Y-axis direction corresponds to the thickness L1 of the first thin-walled portion 59 (see Figure 4). Although the first thin-walled space SS1 is a space formed within the mold 70 together with the molding space C and can therefore be considered a part of the molding space C, in this specification, the first thin-walled space SS1 is defined as a separate space connected to the molding space C.

[0061] The mold 70 may include a first mold 71 and a second mold 74 that clamp the electrode stack 10 from the Z-axis direction. The mold 70 may also include a third mold 77 positioned between the first mold 71 and the second mold 74. As shown in Figure 9, the first mold 71 has a contact surface 72 that abuts against the first end face 10a of the electrode stack 10 and an inner surface 71a that faces the first overhang region R4. Similarly, the second mold 74 has a contact surface 75 that abuts against the second end face 10b of the electrode stack 10 and an inner surface 74a that faces the second overhang region R5.

[0062] In the area where the main body 51 is formed in the X-axis direction, the electrode stack 10 is sandwiched between the contact surface 72 of the first mold 71 and the contact surface 75 of the second mold 74 such that the outer edge of the electrode stack 10 is exposed in the molding space C. In one example, the contact surface 72 of the first mold 71 may contact the end seal material 24 at the position where the spacer 22, the seal material 21, and the separator 14 overlap when viewed from the Z-axis direction. Similarly, the contact surface 75 of the second mold 74 may contact the end seal material 24 at the position where the spacer 22, the seal material 21, and the separator 14 overlap. The current collector 15 may extend to the position where the spacer 22, the seal material 21, and the separator 14 overlap.

[0063] The third mold 77 is positioned between the first mold 71 and the second mold 74 in the Z-axis direction and together with the first mold 71 and the second mold 74 forms a molding space C. The third mold 77 includes a contact surface 77b that abuts against the first mold 71, a contact surface 77c that abuts against the second mold 74, and an inner surface 77a that faces the main body region R3. In the area where the main body portion 51 is formed in the X-axis direction, the inner surface 77a of the third mold 77 is spaced apart from the main body region R3 on the outer surface 20sA by a distance corresponding to the thickness L2 of the main body portion 51 (see Figure 4).

[0064] In one example step S3, first, the second mold 74 is positioned so as to contact the electrode stack 10. In this case, the electrode stack 10 may be placed on the mounting table such that its end, including the outer surface 20sA, protrudes from the mounting table. Subsequently, the electrode stack 10 is sandwiched between the first mold 71 and the second mold 74 by the first mold 71 pressing the electrode stack 10 from the Z-axis direction. After that, the third mold 77 is positioned. The mold 70 only needs to partially cover the outer surface 20sA of the electrode stack 10. In one example, both ends of the outer surface 20sA in the X-axis direction may be exposed to the outside of the mold 70.

[0065] As shown in Figure 10, in the X-axis direction, outside the region where the main body portion 51 is formed and in the region where the first thin-walled portion 59 is formed, the contact surface 72 of the first mold 71 and the contact surface 75 of the second mold 74 extend to the outer surface 20sA, which is the outer circumference of the electrode laminate 10. Furthermore, the third mold 77 has an inner surface 77d that is closer to the outer surface 20sA of the electrode laminate 10 than the inner surface 77a. The inner surface 77d faces the first thin-walled region R6 where the first thin-walled portion 59 is joined on the outer surface 20sA. The distance from the inner surface 77d to the outer surface 20sA corresponds to the thickness L1 of the first thin-walled portion 59 (see Figure 6).

[0066] As shown in Figure 11, at the ends in the X-axis direction, the contact surfaces of the first mold 71 and the second mold 74 extend to the position of the outer surface 20sA of the electrode stack 10, similar to the area where the first thin-walled portion 59 is formed. The third mold 77 also has a contact surface 77e that contacts the outer surface 20sA. When the mold 70 is attached to the electrode stack 10, the contact surface 77e of the third mold 77 may be pressed against the outer surface 20sA of the electrode stack 10.

[0067] Figure 12 schematically shows the contact surface of the mold with respect to the electrode laminate. The contact surface 72 of the first mold 71 and the contact surface 75 of the second mold 74 have similar shapes. In Figure 12, the contact surface 72 of the first mold 71 is shown as a representative example. As shown in Figure 12, grooves are formed on the contact surface 72 of the first mold 71. The grooves in the illustrated example form a mesh pattern when viewed from the Z-axis direction. That is, the grooves are formed by the intersection of a plurality of first straight lines 72a inclined at a first angle and a plurality of second straight lines 72b inclined at a second angle when viewed from the Z-axis direction. Both the first straight lines 72a and the second straight lines 72b intersect in both the X-axis and Y-axis directions. Due to the above shape, the surface roughness of the contact surfaces of the first mold 71 and the second mold 74 is greater than the surface roughness of the forming surface (i.e., inner surface) of the molding space C in the mold 70. Note that both ends of the contact surface 72 in the Y-axis direction may be rounded.

[0068] In step S3, after the mold 70 is attached to the electrode laminate 10, the injection resin part 50 is formed by injecting resin into the molding space C of the mold 70 (step S4). In step S4, the molding space C is filled with resin, and any resin that leaks out of the molding space C may be filled into the first thin-walled space SS1. In step S4, it is not necessary for the first thin-walled space SS1 to be completely filled with resin; it is sufficient if at least some resin enters. That is, the first thin-walled part 59 formed in step S4 does not need to have a rectangular shape corresponding to the first thin-walled space SS1 when viewed from the Y-axis direction, and may have chips at its ends or periphery.

[0069] Furthermore, although the mold 70 is schematically shown in Figures 9 to 11, the mold 70 may have recesses or the like that corresponding to the protruding frame portion 53. Also, for example, the mold 70 may have a holding portion that holds the insert that protrudes from the electrode laminate 10. After the injection resin portion 50 is formed in step S4, the insert is pulled out, thereby forming an opening 52 connected to the communication hole 27 in the injection resin portion 50 that is joined to the electrode laminate 10.

[0070] Figure 13 is a schematic plan view of another example of a battery storage module. Figure 14 is a schematic cross-sectional view of the battery storage module shown in Figure 13. Figure 15 is a schematic cross-sectional view of the mold shown in Figure 13. In the examples shown in Figures 13 to 15, the battery storage module has an injection resin part 150 that has a different shape from the injection resin part 50. The injection resin part 150 includes a main body part 51, a first overhang part 55, a second overhang part 57, a first thin-walled part 59, and a second thin-walled part 159. The main body part 51, the first overhang part 55, the second overhang part 57, and the first thin-walled part 59 have the same configuration as the injection resin part 50, so their description is omitted.

[0071] The second thin-walled portion 159 is formed by connecting to both ends of the first overhang portion 55 and the second overhang portion 57 in the X-axis direction. The second thin-walled portion 159 may also be connected to the first thin-walled portion 59. The second thin-walled portion 159 extends from the first overhang portion 55 and the second overhang portion 57 along the end seal material 24. The thickness L3 of the second thin-walled portion 159 in the Z-axis direction is smaller than the thicknesses L4 and L5 of the first overhang portion 55 and the second overhang portion 57 in the Z-axis direction. For example, the thickness L3 may be 1 / 3 or less of the thickness L4 or thickness L5. Furthermore, the second thin-walled portion 159 and the first thin-walled portion 59 may have the same thickness, and the relationship between the thickness L3 of the second thin-walled portion 159 and the thicknesses L4 and L5 of the first overhang portion 55 and the second overhang portion 57 may be the same as the relationship between the thickness L1 of the first thin-walled portion 59 and the thickness L2 of the main body portion 51. In the illustrated example, the second thin-walled portion 159 has a rectangular shape when viewed from the Z-axis direction, but the shape of the second thin-walled portion 159 is not limited to a rectangular shape.

[0072] As shown in Figure 15, a cross-sectional view of the mold 170 at a position corresponding to the second thin-walled portion 159, the first mold 171, the second mold 174, and the third mold 177 constituting the mold 170 form the first thin-walled space SS1 and the second thin-walled space SS2 for forming the first thin-walled portion 59 and the second thin-walled portion 159. That is, in the range in the X-axis direction where the second thin-walled portion 159 is formed, the first mold 171 has a contact surface 172 that abuts against the first end face 10a (end seal material 24) of the electrode laminate 10, and an inner surface 171a that faces the second thin-walled region R7, which is the region where the second thin-walled portion 159 is joined at the first end face 10a.

[0073] Similarly, the second mold 174 has a contact surface 175 that abuts against the second end face 10b (end seal material 24) of the electrode laminate 10 in the area where the second thin-walled portion 159 is formed in the X-axis direction, and an inner surface 174a that faces the second thin-walled region R7, which is the area where the second thin-walled portion 159 is joined at the second end face 10b. The inner surface 171a of the first mold 171 and the inner surface 174a of the second mold 174 are spaced apart from the electrode laminate 10 by a distance corresponding to the second thin-walled portion 159. The third mold 177 also includes a contact surface 177a that abuts against the first mold 171, a contact surface 177b that abuts against the second mold 174, and an inner surface 177c that faces the outer surface 20sA. In the area where the second thin-walled portion 159 is formed in the X-axis direction, the inner surface 177c of the third mold 177 is spaced apart from the outer surface 20sA by a distance corresponding to the first thin-walled portion 59.

[0074] As resin is injected into the mold 170 while the mold 170 is attached to the electrode laminate 10, the resin filling the molding space C of the mold 170 flows into the first thin-walled space SS1 and the second thin-walled space SS2. This forms the first thin-walled portion 59 and the second thin-walled portion 159.

[0075] Figure 16 is a schematic plan view of yet another example of a battery storage module. Figure 17 is a schematic cross-sectional view of the mold shown in Figure 16. In the examples of Figures 16 and 17, the battery storage module has an injection resin part 250 with a different shape from the injection resin part 150. The injection resin part 250 includes a main body part 51, a first overhang part 55, a second overhang part 57, a first thin-walled part 59, a second thin-walled part 159, and a third thin-walled part 259. The main body part 51, the first overhang part 55, the second overhang part 57, the first thin-walled part 59, and the second thin-walled part 159 have the same configuration as the injection resin part 150, so their description is omitted.

[0076] The third thin-walled portion 259 is formed by connecting to the Y-axis edges of the first overhang portion 55 and the second overhang portion 57, respectively. The third thin-walled portion 259 may also be connected to the second thin-walled portion 159. The third thin-walled portion 259 extends from the first overhang portion 55 and the second overhang portion 57 along the end seal material 24, respectively. The thickness of the third thin-walled portion 259 in the Z-axis direction is smaller than the thickness of the first overhang portion 55 and the second overhang portion 57 in the Z-axis direction, and may be the same as, for example, the thickness of the second thin-walled portion 159. In the illustrated example, the third thin-walled portion 259 has a rectangular shape when viewed from the Z-axis direction, but the shape of the third thin-walled portion 259 is not limited to a rectangular shape.

[0077] As shown in Figure 17, a cross-sectional view of the mold 270 at a position corresponding to the third thin-walled portion 259, the first mold 271 has, in the range in the X-axis direction where the third thin-walled portion 259 is formed, a contact surface 272 that abuts against the first end face 10a (end seal material 24) of the electrode laminate 10, an inner surface 271a facing the third thin-walled region R8 which is the region where the third thin-walled portion 259 is joined at the first end face 10a, and an inner surface 271b facing the first overhang region R4.

[0078] Similarly, the second mold 274 has a contact surface 275 that abuts against the second end face 10b (end seal material 24) of the electrode laminate 10 in the area where the third thin-walled portion 259 is formed in the X-axis direction, an inner surface 274a facing the third thin-walled region R8 which is the area where the third thin-walled portion 259 is joined at the first end face 10a, and an inner surface 274b facing the second overhang region R5. The inner surface 271a of the first mold 271 and the inner surface 274a of the second mold 274 are spaced apart from the electrode laminate 10 (end seal material 24) by a distance corresponding to the third thin-walled portion 259. The third mold 277 also includes a contact surface 277b that abuts against the first mold 271, a contact surface 277c that abuts against the second mold 274, and an inner surface 277a facing the main body region R3.

[0079] As resin is injected into the mold 270 while the mold 270 is attached to the electrode laminate 10, the resin filling the molding space C of the mold 270 flows into the first thin-walled space SS1, the second thin-walled space SS2, and the third thin-walled space SS3. This forms the first thin-walled section 59, the second thin-walled section 159, and the third thin-walled section 259.

[0080] Figure 18 is a schematic cross-sectional view of yet another example of an energy storage module. In the example of Figure 18, the energy storage module has an injection-molded resin part 50, similar to the example of Figure 5, but the energy storage module may also have an injection-molded resin part 150 or an injection-molded resin part 250. In this energy storage module, a laminate sheet 25 may be bonded to the end sealing material 24 that constitutes the first end face 10a and the second end face 10b of the electrode laminate 10. For example, the laminate sheet 25 may be welded to the end sealing material 24. The laminate sheet 25 may be a sheet in which a metal layer, such as aluminum, is covered with a resin layer, similar to the laminate sheet 54.

[0081] For example, the end seal material 24 may be covered with a laminate sheet 25. In the illustrated example, the surface along the first end face 10a of the end seal material 24 joined to the positive terminal electrode 12 and the surface along the second end face 10b of the end seal material 24 joined to the negative terminal electrode 13 are covered with a laminate sheet 25. Viewed from the Z-axis direction, the shape of the laminate sheet 25 matches the shape of the end seal material 24. The laminate sheet 25 may be joined to the end seal material 24 at any stage prior to step S3 described above. By joining the laminate sheet 25 to the outer surface of the end seal material 24, the rigidity of the electrode laminate 10 is improved. This allows the mold to be attached to the electrode laminate 10 more stably, for example, in step S3.

[0082] Figure 19 shows another example of the contact surface of the mold with respect to the electrode stack. Grooves are formed in the contact surface 372 of the mold shown in Figure 19. In the illustrated example, the contact surface 372 has multiple grooves 372a that extend in the X-axis direction when viewed from the Z-axis direction. Each groove 372a is spaced equally apart in the Y-axis direction. Due to this shape, the surface roughness of the contact surface 372 of the mold is greater than the surface roughness of the inner surface of the molding space C in the mold.

[0083] As described above, an example of an energy storage module 1 includes an electrode stack 10 which includes a plurality of electrodes (bipolar electrode 11, positive terminal electrode 12, negative terminal electrode 13) stacked along a first direction, forming an internal space S between adjacent electrodes and a sealing body 20 provided to seal the internal space S, and an injection-molded resin part 50 joined to the sealing body 20. Each of the plurality of electrodes includes a current collector 15 which is rectangular when viewed from the Z-axis direction. The sealing body 20 includes welded ends 23 in which the outer edges of a plurality of frame-shaped members (sealing material 21, spacer 22) which are interposed between the plurality of current collectors 15 and stacked in the Z-axis direction are welded to each other. The sealant 20 has a first end face 10a and a second end face 10b, which are both end faces of the electrode laminate 10 in the Z-axis direction, an outer surface 20sA which is one of the four outer surfaces 20s that constitute the circumferential surface of the welded end 23 and to which the injection resin portion 50 is joined, and a plurality of communication holes 27 that connect the outside of the outer surface 20sA to each of the plurality of internal spaces S. The injection resin portion 50 has a plurality of openings 52 connected to the plurality of communication holes 27 and includes a main body portion 51 that partially covers the outer surface 20sA, a first overhang portion 55 connected to the main body portion 51 that partially covers the first end face 10a, and a second overhang portion 57 connected to the main body portion 51 that partially covers the second end face 10b. The main body portion 51 includes a plurality of protruding frame portions 53 that project in the Y-axis direction intersecting the outer surface 20sA. The multiple protruding frame portions 53 surround the openings 52 connected to each of the multiple communication holes 27 when viewed from the Y-axis direction.

[0084] In the above-described energy storage module 1, a communication hole 27 is provided in the welded end 23 of the sealing body 20 formed on the outer peripheral edge of the electrode stack 10, penetrating to the internal space S. An injection-molded resin part 50 having a protruding frame portion 53 surrounding the communication hole 27 is joined to the sealing body 20. This injection-molded resin part 50 has a main body portion 51 that covers the outer surface 20sA where the welded end portion 23 is formed, a first overhang portion 55 that extends from the main body portion 51 to the first end face 10a of the electrode stack 10, and a second overhang portion 57 that extends from the main body portion 51 to the second end face 10b of the electrode stack 10. In this way, since the injection-molded resin part 50 is provided on only one of the four outer surfaces, an increase in the size of the energy storage module 1 is suppressed. Such an injection-molded resin portion 50 does not require a mold that surrounds the entire circumference of the electrode laminate 10, but can be formed with a mold that is sized to partially cover one outer surface 20sA of the electrode laminate 10. Therefore, it is possible to suppress an increase in the size of the mold required for manufacturing. In addition, by providing the first overhang portion 55 and the second overhang portion 57, the injection-molded resin portion 50 can be firmly bonded to the sealant 20, and moisture permeation and gas permeation along the Z-axis direction between the internal space S and the outside are suppressed.

[0085] The outer surface 20s of the electrode laminate 10 is formed by welding the sealing material 21, the end sealing material 24, and the spacer 22 together. Therefore, the outer surface 20s is not necessarily a flat surface, but may be composed of an uneven end surface. If the outer surface 20s is uneven, the bonding strength between the outer surface 20s and the injection-molded resin part 50 may decrease.

[0086] In one example, the injection-molded resin portion 50 may have a first thin-walled portion 59 connected to the main body portion 51 and joined to the outer surface 20sA along the outer surface 20sA from the main body portion 51, wherein the thickness of the first thin-walled portion 59 in the Y-axis direction is smaller than the thickness of the main body portion 51 in the Y-axis direction. In this configuration, the injection-molded resin portion 50 can be more firmly bonded to the sealant 20 formed on the outer peripheral edge of the electrode laminate 10.

[0087] In one example, the injection-molded resin portion 150 may have a second thin-walled portion 159 connected to the first overhang portion 55 and joined to the first end face 10a along the first overhang portion 55, with the thickness of the second thin-walled portion 159 in the Z-axis direction being smaller than the thickness of the first overhang portion 55 in the Z-axis direction. In another example, the injection-molded resin portion 250 may have a third thin-walled portion 259 connected to the first overhang portion 55 and joined to the first end face 10a along the first overhang portion 55, with the thickness of the third thin-walled portion 259 in the Z-axis direction being smaller than the thickness of the first overhang portion 55 in the Z-axis direction. With this configuration, the injection-molded resin portions 150 and 250 can be more firmly bonded to the sealant 20 formed on the outer periphery of the electrode laminate 10. The thicknesses of the second thin-walled portion 159 and the third thin-walled portion 259 may be the same or different.

[0088] One example of a current collector 15 has a first region R1 in the center of the current collector 15 when viewed from the Z-axis direction, where an active material layer is formed, and a frame-shaped second region R2 that is outside the first region R1. The electrode laminate 10 may also include a plurality of frame-shaped sealing materials 21 provided in the second region R2 of each of the plurality of current collectors 15, and a plurality of spacers 22 interposed between adjacent sealing materials 21 in the Z-axis direction, which together with the plurality of sealing materials 21 define an internal space S between the current collectors 15. In this configuration, the outer edges of the sealing materials 21 and the outer edges of the spacers 22 are welded to each other to form a welded end 23.

[0089] Furthermore, a manufacturing method for one example of an energy storage module 1 includes the steps of: preparing an electrode stack 10 which includes a plurality of electrodes stacked along the Z-axis direction and whose end faces in the Z-axis direction are designated as a first end face 10a and a second end face 10b (step S1); providing welded ends 23 to the electrode stack 10 so as to form an internal space S between adjacent electrodes (step S2); and forming an injection resin portion 50 on the welded ends 23 (step S3). The step of providing the welded ends 23 includes welding the outer edges of a plurality of sealing materials 21, a plurality of spacers 22, and an end sealing material 24 to each other. The process of forming the injection resin part 50 includes the steps of: attaching a mold 70 to the electrode laminate 10 such that a continuous molding space C is formed between a main body region R3 including a plurality of communication holes 27 on the outer surface 20sA, a first overhang region R4 connected to the main body region R3 and partially extending to the first end face 10a, and a second overhang region R5 connected to the main body region R3 and partially extending to the second end face 10b; and molding the injection resin part 50 by injecting resin into the molding space C attached to the electrode laminate 10.

[0090] In the manufacturing method of the energy storage module 1 described above, a mold large enough to surround the entire circumference of the electrode stack 10 is not required. Instead, the injection resin part 50 can be formed using a mold 70 that is large enough to partially cover one outer surface 20sA of the electrode stack 10. Therefore, the size of the mold required for manufacturing can be kept from increasing. In addition, the size of the manufactured energy storage module can be kept from increasing. Furthermore, if the shape of the injection resin part 50 is common, a common mold can be used even for electrode stacks with larger electrodes.

[0091] In one example, the step of attaching the mold 70 may be connected to the molding space C, forming a first thin-walled space SS1 that extends from the molding space C along the outer surface 20sA, and the thickness of the first thin-walled space SS1 in the Y-axis direction is smaller than the thickness of the molding space C in the Y-axis direction. In this configuration, during injection molding, after the molding space C is filled with resin, the resin can leak out from the molding space C into the first thin-walled space SS1. Therefore, it is possible to sufficiently fill the molding space C with resin while mitigating the pressure rise inside the molding space C.

[0092] In one example, the process of installing the mold may be connected to the molding space C to form a second thin-walled space SS2 that extends from the first overhang region R4 along the first end face 10a, and the thickness of the second thin-walled space SS2 in the Z-axis direction is smaller than the thickness of the molding space C in the Z-axis direction in the first overhang region R4. In this configuration, after the molding space C is filled with resin during injection molding, the resin can leak out of the molding space C into the second thin-walled space SS2. Therefore, it is possible to sufficiently fill the molding space C with resin while mitigating the pressure rise within the molding space C.

[0093] In one example, the process of attaching the mold may involve clamping the region of the electrode stack 10 where multiple current collectors 15, multiple sealing materials 21, multiple spacers 22, and multiple separators 14 overlap when viewed from the Z-axis direction, using the mold 70. In this configuration, a region of uniform thickness in the electrode stack 10 is clamped by the mold 70, allowing the mold 70 to stably clamp the electrode stack 10.

[0094] One example of a mold 70 includes a first mold 71 and a second mold 74 that clamp the electrode stack 10 from the Z-axis direction. The surface roughness of the contact surface 72 in the first mold 71 that contacts the electrode stack 10 and the contact surface 75 in the second mold 74 that contacts the electrode stack 10 may be greater than the surface roughness of the forming surface of the molding space C in the mold 70. This configuration allows for an increase in the coefficient of friction between the first mold 71 and the second mold 74 and the electrode stack 10. Therefore, even with a small clamping force, displacement of the electrode stack 10 from the mold 70 can be suppressed.

[0095] Examples of each form of this disclosure have been described above with reference to the drawings, but this disclosure is not limited to the above forms.

[0096] For example, although an example was shown in which the welded end portion 23 is formed on the outside of the edge of the current collector 15, the welded end portion 23 may be formed along the edge of the current collector 15, or it may be formed inward beyond the edge of the current collector 15.

[0097] Furthermore, although a rectangular active material layer was given as an example, the shape of the active material layer is not particularly limited as long as it can be considered rectangular. For example, the active material layer may be divided into multiple regions spaced apart from each other, or it may have a shape other than a rectangle. In this case, the shape of the active material layer may be considered to be the smallest rectangle that includes all the regions in which the active material layer is formed, having a long side along the long side of the current collector and a short side along the short side of the current collector.

[0098] Furthermore, although an example was shown in which the first thin-walled portion is formed at both ends of the main body 51 in the X-axis direction, the first thin-walled portion may be formed only at one end of the main body 51 in the X-axis direction. Also, although an example was shown in which the first thin-walled portion is formed over the entire Z-axis direction at the X-axis end of the main body 51, the first thin-walled portion may be formed only in a part of the X-axis direction. In other words, the size of the first thin-walled portion in the Z-axis direction may be smaller than the size of the main body in the Z-axis direction.

[0099] Furthermore, although a spacer 22 with rectangular outer and inner edges has been given as an example, the planar shape of the spacer 22 is not limited to this. For example, the width of the spacer 22 may be greater than the width of the sealing material 21 in the region along the outer surface 20sA where a mold is provided in the X-axis direction, and smaller than the width of the sealing material 21 in the region shifted in the X-axis direction from the region where the mold is provided. That is, the inner edge of the spacer 22 may be located inside the inner edge of the sealing material 21 in the region along the outer surface 20sA where a mold is provided, and outside the inner edge of the sealing material 21 in other regions.

[0100] Furthermore, while an example was shown where the thickness L2 of the main body 51 in the Y-axis direction is 2.0 ± 0.5 mm, the thickness L2 of the main body 51 may be larger or smaller. Also, while an example was shown where the thickness of the protruding frame 53 in the Y-axis direction is approximately 0.5 mm to 6.0 mm, the thickness of the protruding frame 53 is not limited to this. Furthermore, while an example was shown where the thickness L1 of the first thin-walled portion 59 is 1 / 3 or less of the thickness L2 of the main body 51, the thickness L1 of the first thin-walled portion 59 is not limited to this, and may be, for example, approximately 1 / 2 of the thickness L2 of the main body 51. Although 0.5 mm was given as a specific example of the thickness L1 of the first thin-walled portion 59, the thickness L1 is not limited to this.

[0101] The form of this disclosure may be shown as follows: [1] An electrode stack comprising a plurality of electrodes stacked along a first direction, wherein the electrode stack comprises a sealant provided to form an internal space between adjacent electrodes and to seal the internal space, The sealing body comprises an injection resin portion bonded to the sealing body, Each of the plurality of electrodes includes a current collector that is rectangular in shape when viewed from the first direction, The aforementioned encapsulant is The system includes welded ends where the outer edges of multiple frame-shaped members, which are interposed between multiple current collectors and stacked in the first direction, are welded to each other. The first end face and the second end face, which are both end faces of the electrode stack in the first direction, One of the four outer surfaces constituting the circumferential surface of the welded end, the injection port surface to which the injection resin portion is joined, It has a plurality of communication holes that connect the outer surface of the liquid injection port to each of the plurality of internal spaces, The injection resin part is, A main body having multiple openings connected to each of the multiple communication holes, and partially covering the liquid injection port surface, A first overhang portion connected to the main body portion and partially covering the first end face, It includes a second overhang portion that connects to the main body portion and partially covers the second end face, The main body includes a plurality of protruding frame portions that protrude in a second direction intersecting the liquid injection port surface, The plurality of protruding frame portions are energy storage modules that surround each of the plurality of openings when viewed from the second direction. [2] The injection-molded resin portion is a first thin-walled portion connected to the main body portion, and has the first thin-walled portion joined to the liquid injection port surface along the liquid injection port surface from the main body portion, The energy storage module according to [1], wherein the thickness of the first thin-walled portion in the second direction is smaller than the thickness of the main body portion in the second direction. [3] The injection-molded resin portion is a second thin-walled portion connected to the first overhang portion, and has the second thin-walled portion joined to the first end face along the first end face from the first overhang portion, The energy storage module according to [1] or [2], wherein the thickness of the second thin-walled portion in the first direction is smaller than the thickness of the first overhang portion in the first direction. [4] The current collector has a first region where an active material layer is formed, located in the center of the current collector when viewed from the first direction, and a frame-shaped second region located outside the first region. The aforementioned frame-shaped member is Multiple frame-shaped sealing materials provided in the second region of each of the multiple current collectors, A power storage module according to any one of [1] to [3], comprising: a plurality of spacers interposed between adjacent sealing materials in the first direction, which together with the plurality of sealing materials define the internal space between the current collectors. [5] A method for manufacturing an energy storage module, A step of preparing an electrode stack comprising a plurality of electrodes stacked along a first direction, wherein both end faces in the first direction are designated as the first end face and the second end face, A step of providing welded ends to the electrode stack such that an internal space is formed between adjacent electrodes, The process includes providing an injection resin portion at the welded end, Each of the plurality of electrodes includes a current collector that is rectangular in shape when viewed from the first direction, The step of providing the welded end includes the step of welding the outer edges of a plurality of frame-shaped members that are interposed between a plurality of current collectors and stacked in the first direction to each other, The liquid injection port surface, which is one of the four outer surfaces of the welded end opposite to the internal space, has a plurality of communication holes that communicate with each of the plurality of internal spaces. The step of providing the injection resin part is, A step of attaching a mold that partially covers the liquid injection port surface to the electrode stack such that a continuous molding space is formed between the main body region of the liquid injection port surface, which includes the plurality of communication holes, a first overhang region connected to the main body region and partially extending to the first end face of the electrode stack, and a second overhang region connected to the main body region and partially extending to the second end face of the electrode stack; A method for manufacturing an energy storage module, comprising the step of injecting resin into the molding space of the mold attached to the electrode stack. [6] The step of installing the mold involves connecting to the molding space and forming a first thin-walled space that extends from the molding space along the liquid injection port surface, The method for manufacturing an energy storage module according to [5], wherein the thickness of the first thin-walled space in a second direction intersecting the liquid injection port surface is smaller than the thickness of the molded space in the main body region in the second direction. [7] The step of installing the mold is to connect to the molding space and form a second thin-walled space that extends from the first overhang region along the first end face, A method for manufacturing an energy storage module according to [5] or [6], wherein the thickness of the second thin-walled space in the first direction is smaller than the thickness of the molding space in the first overhang region in the first direction. [8] The current collector has a first region where an active material layer is formed, located in the center of the current collector when viewed from the first direction, and a frame-shaped second region located outside the first region. The aforementioned frame-shaped member is Multiple frame-shaped sealing materials provided in the second region of each of the multiple current collectors, The present invention includes a plurality of spacers interposed between adjacent sealing materials in the first direction, which together with the plurality of sealing materials define the internal space between the current collector, The electrode laminate includes a plurality of separators arranged between the plurality of current collectors, the outer edge of each of the separators being arranged between the plurality of sealing materials and the plurality of spacers, The method for manufacturing an energy storage module according to any one of [5] to [7], wherein the step of attaching the mold is to clamp the region of the electrode stack in which the plurality of current collectors, the plurality of sealing materials, the plurality of spacers, and the plurality of separators overlap when viewed from the first direction, with the mold. [9] The mold includes a first mold and a second mold that clamp the electrode laminate from a first direction. A method for manufacturing an energy storage module according to any one of [5] to [8], wherein the surface roughness of the surface in contact with the electrode stack in the first mold and the surface in contact with the electrode stack in the second mold is greater than the surface roughness of the forming surface of the molding space in the mold. [Explanation of Symbols]

[0102] 1...Energy storage module, 10...Electrode stack, 11...Bipolar electrode (electrode), 12...Positive terminal electrode (electrode), 13...Negative terminal electrode (electrode), 15...Current collector, 20...Sealing body, 20sA...Outer surface (injection port surface), 21...Sealing material (frame-shaped member), 22...Spacer (frame-shaped member), 24...End sealing material (sealing material, frame-shaped member), 27...Communication hole, 50, 150, 250...Injection resin part, 51...Main body part, 53...Protruding frame part, 55...First overhang part, 57...Second overhang part.

Claims

1. An electrode stack comprising a plurality of electrodes stacked along a first direction, wherein the electrode stack comprises a sealing body provided to form an internal space between adjacent electrodes and to seal the internal space, The sealing body comprises an injection resin portion bonded to the sealing body, Each of the plurality of electrodes includes a current collector that is rectangular in shape when viewed from the first direction, The aforementioned encapsulant is The system includes welded ends where the outer edges of multiple frame-shaped members, which are interposed between multiple current collectors and stacked in the first direction, are welded to each other. The first end face and the second end face, which are both end faces of the electrode stack in the first direction, One of the four outer surfaces constituting the circumferential surface of the welded end, the injection port surface to which the injection resin portion is joined, It has a plurality of communication holes that connect the outer surface of the liquid injection port to each of the plurality of internal spaces, The injection resin part is, A main body having multiple openings connected to each of the multiple communication holes, and partially covering the liquid injection port surface, A first overhang portion connected to the main body portion and partially covering the first end face, It includes a second overhang portion that connects to the main body portion and partially covers the second end face, The main body includes a plurality of protruding frame portions that protrude in a second direction intersecting the liquid injection port surface, The plurality of protruding frame portions surround each of the plurality of openings when viewed from the second direction. The injection-molded resin portion is a first thin-walled portion connected to the main body portion, and has the first thin-walled portion joined to the liquid injection port surface along the liquid injection port surface from the main body portion, An energy storage module wherein the thickness of the first thin-walled portion in the second direction is smaller than the thickness of the main body portion in the second direction.

2. The injection-molded resin portion is a second thin-walled portion connected to the first overhang portion, and has the second thin-walled portion joined to the first end face along the first end face from the first overhang portion. The energy storage module according to claim 1, wherein the thickness of the second thin-walled portion in the first direction is smaller than the thickness of the first overhang portion in the first direction.

3. An electrode stack comprising a plurality of electrodes stacked along a first direction, wherein the electrode stack comprises a sealing body provided to form an internal space between adjacent electrodes and to seal the internal space, The sealing body comprises an injection resin portion bonded to the sealing body, Each of the plurality of electrodes includes a current collector that is rectangular in shape when viewed from the first direction, The aforementioned encapsulant is The system includes welded ends where the outer edges of multiple frame-shaped members, which are interposed between multiple current collectors and stacked in the first direction, are welded to each other. The first end face and the second end face, which are both end faces of the electrode stack in the first direction, One of the four outer surfaces constituting the circumferential surface of the welded end, the injection port surface to which the injection resin portion is joined, It has a plurality of communication holes that connect the outer surface of the liquid injection port to each of the plurality of internal spaces, The injection resin part is, A main body having multiple openings connected to each of the multiple communication holes, and partially covering the liquid injection port surface, A first overhang portion connected to the main body portion and partially covering the first end face, It includes a second overhang portion that connects to the main body portion and partially covers the second end face, The main body includes a plurality of protruding frame portions that protrude in a second direction intersecting the liquid injection port surface, The plurality of protruding frame portions surround each of the plurality of openings when viewed from the second direction. The current collector has a first region where an active material layer is formed, located in the center of the current collector when viewed from the first direction, and a frame-shaped second region located outside the first region. The aforementioned frame-shaped member is Multiple frame-shaped sealing materials provided in the second region of each of the multiple current collectors, A power storage module comprising: a plurality of spacers interposed between adjacent sealing materials in the first direction, which together with the plurality of sealing materials define the internal space between the current collectors.

4. A method for manufacturing an energy storage module, A step of preparing an electrode stack comprising a plurality of electrodes stacked along a first direction, wherein both end faces in the first direction are designated as the first end face and the second end face, A step of providing welded ends to the electrode stack such that an internal space is formed between adjacent electrodes, The process includes providing an injection resin portion at the welded end, Each of the plurality of electrodes includes a current collector that is rectangular in shape when viewed from the first direction, The step of providing the welded end includes the step of welding the outer edges of a plurality of frame-shaped members that are interposed between a plurality of current collectors and stacked in the first direction to each other, The liquid injection port surface, which is one of the four outer surfaces of the welded end opposite to the internal space, has a plurality of communication holes that communicate with each of the plurality of internal spaces. The step of providing the injection resin part is, A step of attaching a mold that partially covers the liquid injection port surface to the electrode stack such that a continuous molding space is formed between the main body region of the liquid injection port surface, which includes the plurality of communication holes, a first overhang region connected to the main body region and partially extending to the first end face of the electrode stack, and a second overhang region connected to the main body region and partially extending to the second end face of the electrode stack; The process includes injecting resin into the molding space of the mold attached to the electrode stack, The step of installing the mold involves connecting to the molding space and forming a first thin-walled space that extends from the molding space along the liquid injection port surface, A method for manufacturing an energy storage module, wherein the thickness of the first thin-walled space in a second direction intersecting the liquid injection port surface is smaller than the thickness of the molded space in the main body region in the second direction.

5. The step of installing the mold is to connect to the molding space and form a second thin-walled space that extends from the first overhang region along the first end face, The method for manufacturing an energy storage module according to claim 4, wherein the thickness of the second thin-walled space in the first direction is smaller than the thickness of the molding space in the first overhang region in the first direction.

6. A method for manufacturing an energy storage module, A step of preparing an electrode stack comprising a plurality of electrodes stacked along a first direction, wherein both end faces in the first direction are designated as the first end face and the second end face, A step of providing welded ends to the electrode stack such that an internal space is formed between adjacent electrodes, The process includes providing an injection resin portion at the welded end, Each of the plurality of electrodes includes a current collector that is rectangular in shape when viewed from the first direction, The step of providing the welded end includes the step of welding the outer edges of a plurality of frame-shaped members that are interposed between a plurality of current collectors and stacked in the first direction to each other, The liquid injection port surface, which is one of the four outer surfaces of the welded end opposite to the internal space, has a plurality of communication holes that communicate with each of the plurality of internal spaces. The step of providing the injection resin part is, A step of attaching a mold that partially covers the liquid injection port surface to the electrode stack such that a continuous molding space is formed between the main body region of the liquid injection port surface, which includes the plurality of communication holes, a first overhang region connected to the main body region and partially extending to the first end face of the electrode stack, and a second overhang region connected to the main body region and partially extending to the second end face of the electrode stack; The process includes injecting resin into the molding space of the mold attached to the electrode stack, The current collector has a first region where an active material layer is formed, located in the center of the current collector when viewed from the first direction, and a frame-shaped second region located outside the first region. The aforementioned frame-shaped member is Multiple frame-shaped sealing materials provided in the second region of each of the multiple current collectors, It includes a plurality of spacers interposed between adjacent sealing materials in the first direction, which together with the plurality of sealing materials define the internal space between the current collector, The electrode laminate includes a plurality of separators arranged between the plurality of current collectors, the outer edge of each of the separators being arranged between the plurality of sealing materials and the plurality of spacers, A method for manufacturing an energy storage module, comprising the step of attaching the mold, wherein, when viewed from the first direction, the region of the electrode stack in which the plurality of current collectors, the plurality of sealing materials, the plurality of spacers, and the plurality of separators overlap is sandwiched by the mold.

7. A method for manufacturing an energy storage module, A step of preparing an electrode stack comprising a plurality of electrodes stacked along a first direction, wherein both end faces in the first direction are designated as the first end face and the second end face, A step of providing welded ends to the electrode stack such that an internal space is formed between adjacent electrodes, The process includes providing an injection resin portion at the welded end, Each of the plurality of electrodes includes a current collector that is rectangular in shape when viewed from the first direction, The step of providing the welded end includes the step of welding the outer edges of a plurality of frame-shaped members that are interposed between a plurality of current collectors and stacked in the first direction to each other, The liquid injection port surface, which is one of the four outer surfaces of the welded end opposite to the internal space, has a plurality of communication holes that communicate with each of the plurality of internal spaces. The step of providing the injection resin part is, A step of attaching a mold that partially covers the liquid injection port surface to the electrode stack such that a continuous molding space is formed between the main body region of the liquid injection port surface, which includes the plurality of communication holes, a first overhang region connected to the main body region and partially extending to the first end face of the electrode stack, and a second overhang region connected to the main body region and partially extending to the second end face of the electrode stack; The process includes injecting resin into the molding space of the mold attached to the electrode stack, The mold includes a first mold and a second mold that clamp the electrode laminate from the first direction, A method for manufacturing an energy storage module, wherein the surface roughness of the surface in contact with the electrode stack in the first mold and the surface in contact with the electrode stack in the second mold are greater than the surface roughness of the forming surface of the molding space in the mold.

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