Method for manufacturing energy storage modules, and energy storage modules

Abstract

To provide a method for manufacturing a power storage module which can improve reliability while suppressing reduction in volume energy density, and to provide the power storage module.SOLUTION: A method for manufacturing a power storage module includes: a step S104 of laminating a plurality of electrode units A1 to A3 in a Z direction while interposing a spacer 22 between seal materials 21, and thereby constituting an electrode laminate 10 and a resin laminate 20A; steps S105 and S106 of welding the adjacent seal materials 21 in the Z direction and the spacer 22, and thereby forming a sealing body 20 for sealing an internal space S, after the step S104; and a step S107 of storing a battery body 1A in a container 30 constituted of a laminate film 30L, after the steps S105 and S106. The steps S105 and S106 form the sealing body 20 so that corner parts 20r of the sealing body 20 have chamfered parts 20p when viewed from the Z direction.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] Patent Document 1 describes a laminated outer package battery. This battery includes a rectangular plate-shaped electrode group, a rectangular frame-shaped spacer, and a laminated outer package that accommodates these together with a non-aqueous electrolyte. The laminated outer package has a first metal laminated film member having an accommodation recess. A spacer as a separate member is attached to the outer peripheral surface of the electrode group so as to be interposed between the outer peripheral surface of the electrode group and the inner side surface of the accommodation recess. [Prior Art Literature] [Patent Literature]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2020-140874 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] Incidentally, in a power storage device that accommodates a laminate formed by laminating a plurality of rectangular electrodes or the like in plan view in a laminated outer package formed of a laminated film member, there is a problem that the right-angled corners of the laminate contact the laminated film member, which damages the laminated outer package. In the battery described in Patent Document 1, a spacer that is a separate member from the electrode group is provided around the electrode group accommodated inside the laminated outer package, thereby suppressing damage to the laminated outer package caused by contact with the corners of the electrode group.

[0005] However, in the battery described in Patent Document 1, since a spacer provided as a separate member from the electrode group is used to suppress damage to the laminated outer package, there arises a problem that the volumetric energy density of the battery decreases.

[0006] Therefore, the purpose of this disclosure is to provide a method for manufacturing an energy storage module that can improve reliability while suppressing a decrease in volumetric energy density, and an energy storage module. [Means for solving the problem]

[0007] The method for manufacturing an energy storage module according to this disclosure comprises: a first step of preparing a plurality of electrode units, each including an electrode with a current collector and a sealing material provided on the periphery of the current collector; a second step of stacking the plurality of electrode units in a first direction with frame-shaped spacers interposed between the sealing materials, thereby forming a first laminate including a plurality of electrodes and a second laminate including a plurality of sealing materials and a plurality of spacers, which surrounds the first laminate; a third step of forming a sealing body from the second laminate to seal the internal space formed between the electrodes by welding adjacent sealing materials and spacers in the first direction; and a fourth step of housing the battery body, including the first laminate and the sealing body, in a container made of a laminate film including a metal layer, wherein in the third step, the sealing body is formed such that the first corner, which is the corner of the sealing body when viewed from the first direction, has a chamfered portion.

[0008] In this manufacturing method, first, multiple electrode units, each containing an electrode and a sealing material welded to the electrode, are stacked with spacers interposed between the sealing materials. This forms an electrode stack (first stack) containing multiple electrodes and a second stack containing multiple sealing materials and multiple spacers. Subsequently, by welding adjacent sealing materials and spacers in the stacking direction (first direction), a sealing body that has the function of sealing the internal space formed between the electrodes is formed from the second stack. This forms a battery body having an electrode stack and a sealing body surrounding the electrode stack. Finally, a power storage module is obtained by housing this battery body in a container made of laminate film.

[0009] In this manufacturing method, when forming the sealant, the first corner of the sealant, which is the corner of the sealant when viewed from the stacking direction, is made to have a chamfered portion. Therefore, damage to the metal layer of the laminate film when the corner of the sealant comes into contact with the laminate film is suppressed, and the reliability of the energy storage module is improved. In particular, in this manufacturing method, in order to suppress damage to the metal layer of the laminate film and improve the reliability of the energy storage module, a sealant that is formed integrally with the electrode laminate and has the function of sealing the electrode laminate is used. Therefore, in order to suppress damage to the container made of laminate film, compared to the case in which a spacer as a separate component is housed in the container together with the battery body, the volume of the battery body housed in the container can be increased, and the decrease in the volumetric energy density of the energy storage module is suppressed.

[0010] In the energy storage module manufacturing method according to this disclosure, in the third step, the sealing body may be formed such that the first corner has a chamfered portion by chamfering the corners of the sealing material and the spacer and then welding the sealing material and the spacer together. In this case, the chamfering of the sealing material and the spacer is performed before forming the sealing body by welding the sealing material and the spacer together. Therefore, a more sufficient sealing distance (width of the welded portion) is ensured compared to the case in which the chamfering (removal) of the welded portion is performed after welding the sealing material and the spacer together.

[0011] In the energy storage module manufacturing method according to this disclosure, in the third step, after welding the sealing material and the spacer to form a sealed body, a chamfered portion may be formed on the first corner. In this case, the chamfering of the corner (first corner) is performed after the sealed body is formed. Therefore, compared to the case in which welding is performed after chamfering the sealing material and spacer, the dimensional accuracy of the chamfered portion is more reliably ensured.

[0012] In the energy storage module manufacturing method according to this disclosure, the container includes a first member having a recess formed therein and a second member sealing the recess, and in the fourth step, a battery body may be housed in the recess and the recess may be sealed by the second member. In this way, when forming a deeper recess in the laminate film compared to the case where recesses are provided in both members constituting the container, a chamfered shape may be formed on the second corner of the recess for manufacturing reasons. Therefore, in order to avoid the right-angle corner of the contents of the recess coming into contact with the second corner of the chamfered shape, it is more effective to provide a chamfered portion on the first corner of the sealant as described above to suppress damage to the metal layer of the laminate film.

[0013] The energy storage module manufacturing method according to this disclosure includes a fifth step after the fourth step, in which the pressure inside the container is reduced. The second corner facing the corner of the seal when the battery is housed in the container has a chamfered shape. The chamfered shape of the second corner corresponds to the shape of the chamfered part of the first corner, and the size of the chamfered part of the first corner may be greater than or equal to the size of the chamfered shape of the second corner. In this case, when the battery is housed in the container, the amount of gap between the battery and the container can be reduced. As a result, deformation of the laminate film, such as wrinkles forming in the laminate film, is less likely to occur when the pressure inside the container is reduced.

[0014] The energy storage module according to this disclosure comprises a battery body having a first laminate including a current collector and a plurality of electrodes stacked in a first direction, a cylindrical sealant provided so as to surround the first laminate and for sealing the internal space formed between the electrodes, and a container made of a laminate film including a metal layer for housing the battery body, wherein the sealant has a plurality of sealing materials provided on the peripheral edge of each current collector of the plurality of electrodes, a plurality of spacers interposed between adjacent sealing materials, and a welded end formed by welding the end of the plurality of sealing materials opposite to the internal space and the end of the plurality of spacers opposite to the internal space, and the first corner, which is the corner of the sealant when viewed from the first direction, has a chamfered portion.

[0015] In this energy storage module, the corners (first corners) of the sealant have chamfered edges. This suppresses damage to the metal layer of the laminate film when the corners of the sealant come into contact with the laminate film, thereby improving reliability. Furthermore, in order to suppress damage to the metal layer of the laminate film and improve reliability, this energy storage module utilizes a sealant that is integrally formed with the electrode stack and has the function of sealing the electrode stack. Therefore, compared to the case where a spacer is housed in the container as a separate component along with the battery body to suppress damage to the container made of laminate film, the volume of the battery body housed in the container can be increased, and the decrease in the volumetric energy density of the energy storage module is suppressed. [Effects of the Invention]

[0016] According to this disclosure, it is possible to provide a method for manufacturing an energy storage module that can improve reliability while suppressing a decrease in volumetric energy density, and an energy storage module. [Brief explanation of the drawing]

[0017] [Figure 1] Figure 1 is a simulated cross-section of the energy storage module according to this embodiment. [Figure 2] Figure 2 shows one step of the energy storage module manufacturing method according to this embodiment. [Figure 3] Figure 3 shows one step of the energy storage module manufacturing method according to this embodiment. [Figure 4] Figure 4 shows one step in the energy storage module manufacturing method according to this embodiment. [Figure 5] Figure 5 shows one step in the energy storage module manufacturing method according to this embodiment. [Figure 6] Figure 6 shows one step in the energy storage module manufacturing method according to this embodiment. [Figure 7] Figure 7 shows one step in the energy storage module manufacturing method according to this embodiment. [Figure 8] Figure 8 shows one step in the manufacturing method of an energy storage module according to a modified example. [Figure 9] Fig. 9 is a schematic cross-sectional view showing an electricity storage module according to a modification of double-sided embossing. [Figure 10] Fig. 10 is a schematic cross-sectional view showing an electricity storage device configured by stacking the electricity storage modules shown in Fig. 9. MODE FOR CARRYING OUT THE INVENTION

[0018] Hereinafter, an electricity storage module according to an embodiment will be described with reference to the drawings. In the description of the respective drawings, the same or corresponding elements are denoted by the same reference signs, and duplicate explanations may be omitted. In addition, an orthogonal coordinate system that defines an X direction, a Y direction orthogonal to the X direction, and a Z direction orthogonal to both the X direction and the Y direction may be shown in each drawing.

[0019] Fig. 1 is a schematic cross-sectional view of the electricity storage module according to the present embodiment. The electricity storage module 1 shown in Fig. 1 is an electricity storage module used, for example, for batteries of various vehicles such as forklifts, hybrid vehicles, and electric vehicles. The electricity storage module 1 is a secondary battery such as a nickel-hydrogen secondary battery or a lithium ion secondary battery. The electricity storage module 1 may be an electric double layer capacitor or a solid-state battery. Here, a case where the electricity storage module 1 is a lithium ion secondary battery is exemplified.

[0020] The electricity storage module 1 includes an electrode laminate 10 (first laminate) and a sealing body 20. The electrode laminate 10 includes a plurality of electrodes laminated along the Z direction (first direction). The plurality of electrodes include a plurality of bipolar electrodes 11, a negative terminal electrode 12, and a positive terminal electrode 13. A separator 14 is interposed between electrodes adjacent to each other.

[0021] 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, for example, in the shape of a rectangular sheet. 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, which is the opposite side of the one side 15a. Multiple bipolar electrodes 11 are stacked such that the positive electrode active material layer 16 of one bipolar electrode 11 faces the negative electrode active material layer 17 of another bipolar electrode 11. Here, one side 15a of the current collector 15 is the surface facing one direction in the Z direction (the direction from the positive terminal electrode 13 to the negative terminal electrode 12 in Figure 1), and the other side 15b of the current collector 15 is the surface facing the other direction in the Z direction (the direction from the negative terminal electrode 12 to the positive terminal electrode 13 in Figure 1).

[0022] The positive electrode active material layer 16 and the negative electrode active material layer 17 are rectangular in shape when viewed from the Z direction. The negative electrode active material layer 17 is slightly larger than the positive electrode active material layer 16 when viewed from the Z direction. In other words, in a plan view from the Z 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.

[0023] The negative electrode terminal electrode 12 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 12 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 12. The negative electrode terminal electrode 12 is laminated on the bipolar electrode 11 at one end in the X direction of the electrode laminate 10. The negative electrode terminal electrode 12 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.

[0024] The positive terminal electrode 13 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 13 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, which is the opposite side 15a 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 13. The positive terminal electrode 13 is laminated on the bipolar electrode 11 at one end in the Z direction of the electrode laminate 10. The positive terminal electrode 13 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.

[0025] In this embodiment, the current collectors of the bipolar electrode 11, the negative terminal electrode 12, and the positive terminal electrode 13 are all denoted by the same reference numeral as current collector 15. However, the current collectors of the bipolar electrode 11, the negative terminal electrode 12, and the positive terminal electrode 13 may be the same as or different from each other.

[0026] The separator 14 is positioned between adjacent bipolar electrodes 11, between the negative electrode terminal electrode 12 and the bipolar electrode 11, and between the positive electrode terminal electrode 13 and the bipolar electrode 11. The separator 14 is interposed between the positive electrode active material layer 16 and the negative electrode active material layer 17. The separator 14 is a component that allows charge carriers such as lithium ions to pass through, and by isolating the positive electrode active material layer 16 and the negative electrode active material layer 17, it prevents short circuits caused by contact between adjacent electrodes.

[0027] The current collector 15 is a chemically inert electrical conductor that allows current to continue to flow through the positive electrode active material layer 16 and the negative electrode active material layer 17 during the discharge or 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 and / or conductive resin material.

[0028] 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. The current collector 15 may be an alloy foil of the above metals or a foil formed by integrating multiple metal foils. If the current collector 15 is in the form of a foil, its thickness may be, for example, 1 μm to 200 μm. In this embodiment, the current collector 15 is a foil formed by integrating aluminum foil and copper foil, or aluminum foil.

[0029] 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.

[0030] 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.

[0031] 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, negative electrode terminal electrode 12, positive electrode terminal electrode 13). Examples of conductive additives include acetylene black, carbon black, or graphite.

[0032] 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 crosslinks; and starch-acrylic acid graft polymers. These binders can be used individually or in combination. Examples of solvents for the binders include water and N-methyl-2-pyrrolidone (NMP).

[0033] 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 electrolyte impregnated into the separator 14 is a liquid electrolyte (electrolyte solution) containing a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent.

[0034] As the electrolyte salt of the electrolyte solution, known lithium salts such as LiClO4, LiAsF6, LiPF6, LiBF4, LiCF3SO3, LiN(FSO2)2, and LiN(CF3SO2)2 may be used. Furthermore, as the non-aqueous solvent, known solvents such as cyclic carbonates, cyclic esters, linear carbonates, linear esters, and ethers may be used. In addition, two or more of these known solvent materials may be used in combination.

[0035] The sealant 20 is formed in a rectangular cylindrical shape on the periphery of the electrode stack 10 so as to surround the electrode stack 10 when viewed from the first direction D1. The sealant 20 can be joined (welded) to one side 15a and the other side 15b of the current collector 15 at the periphery 15c of each current collector 15. The sealant 20 is intended to form an internal space S between adjacent current collectors 15 in the Z direction and to seal each of these internal spaces S. An electrolyte (e.g., electrolyte solution) is contained in each internal space S. The sealant 20 can prevent the electrolyte solution contained in the internal space S from flowing out to the outside. In addition, the sealant 20 can prevent air, moisture, etc. from entering the internal space S from outside the electrode stack 10.

[0036] 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.

[0037] The sealing body 20 includes a plurality of resin sealing materials 21 and a plurality of resin spacers 22. The sealing materials 21 are provided on each of the current collectors 15. Therefore, the plurality of sealing materials 21 are stacked along the Z direction. The sealing material 21 is frame-shaped (here, rectangular frame-shaped) when viewed from the Z direction and is provided on the peripheral edge 15c of the current collector 15. 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, covering the peripheral edge 15c. That is, on one surface 15a and the other surface 15b of the current collector 15, the sealing material 21 has an inner part that overlaps the current collector 15 when viewed from the Z direction, and an outer part that is located outside the edge of the current collector 15, and a pair of adjacent sealing materials 21 on either side of the current collector 15 are connected by their outer parts. The inner portion of the sealing material 21 can be welded to one side 15a and the other side 15b of the current collector 15, respectively. In this embodiment, the sealing material 21 is welded to both the one side 15a and the other side 15b of the current collector 15.

[0038] In this embodiment, the sealing material provided on the current collector 15 of the bipolar electrode 11, the current collector 15 of the negative terminal electrode 12, and the current collector 15 of the positive terminal electrode 13 are all denoted by the same reference numeral as sealing material 21. However, the sealing material provided on the current collector 15 of the bipolar electrode 11, the sealing material provided on the current collector 15 of the negative terminal electrode 12, and the sealing material provided on the current collector 15 of the positive terminal electrode 13 may be the same as or different from each other.

[0039] The spacer 22 is positioned between each of the adjacent sealing materials 21 in the Z direction. Thus, the spacer 22, together with the pair of adjacent sealing materials 21 in the Z direction, maintains the spacing between adjacent current collectors 15 in the Z direction. The internal space S is defined by the pair of adjacent current collectors 15 in the Z direction, the spacer 22, and the pair of sealing materials 21 adjacent to the spacer 22. The spacer 22 has a frame shape (here, a rectangular frame shape) when viewed from the Z direction and is positioned on the peripheral edge 15c of the current collector 15 when viewed from the Z direction. The end of the separator 14 may be held between the sealing material 21 and the spacer 22. The end of the separator 14 may be fixed by welding to at least one of the sealing material 21 and the spacer 22.

[0040] A portion of the ends of the multiple sealing materials 21 that are located outside the edge of the current collector 15 (a portion of the end opposite to the internal space S), and a portion of the ends of the multiple spacers 22 that are located outside the edge of the current collector 15 (a portion of the end opposite to the internal space S), are welded together and integrated. That is, the sealing body 20 includes a welded end portion 23 formed by the welding and integration of the ends of the multiple sealing materials 21 and the ends of the multiple spacers 22. When viewed from the Z direction, the welded end portion 23 has a frame shape that surrounds the electrode stack 10 and constitutes the outer periphery of the sealing body 20. Therefore, the outer surface of the welded end portion 23 forms the outer surface of the sealing body 20. In this embodiment, the spacers 22 are not welded to the inner portion of adjacent sealing materials 21 in the Z direction (the portion that overlaps with the current collector 15 when viewed from the Z direction), but adjacent spacers 22 and a portion of the inner portion of the sealing material 21 may be welded together.

[0041] Furthermore, conductive members 40 are laminated via a metal layer 33, described later, on the portions exposed from the sealing body 20 on the other side 15b of the current collector 15 of the negative terminal electrode 12 and on one side 15a of the current collector 15 of the positive terminal electrode 13. Each pair of conductive members 40 is electrically connected to the current collector 15 of the negative terminal electrode 12 and the current collector 15 of the positive terminal electrode 13 via a highly conductive metal layer 33. Each pair of conductive members 40 functions as a terminal for drawing current from the energy storage module 1. The conductive members 40 can be used to electrically connect multiple energy storage modules 1. In addition, the conductive members 40 can be used as members for applying a restraining load to the electrode stack 10. That is, if a restraining member (not shown) that restrains the energy storage module 1 from the Z direction is arranged, a restraining load is applied to the electrode stack 10 via the conductive members 40. Furthermore, cooling channels may be formed in the conductive members 40. The energy storage module 1 can be cooled by circulating a cooling medium through the cooling channel formed in the conductive member 40.

[0042] The electrode stack 10 and the sealant 20 described above constitute a battery body 1A having a battery function in the energy storage module 1. The sealant 20 constitutes the outer periphery of the battery body 1A. The energy storage module 1 includes a container 30 that houses this battery body 1A.

[0043] The container 30 is made of a laminate film 30L. The laminate film 30L may include a metal layer 33, a first resin layer 34, and a second resin layer 35. The first resin layer 34 is laminated on the metal layer 33 on one side of the metal layer 33 (the side facing the battery body 1A). The second resin layer 35 is laminated on the metal layer 33 on the other side of the metal layer 33 (the side opposite to the battery body 1A). In other words, the metal layer 33 is sandwiched between the first resin layer 34 and the second resin layer 35.

[0044] The metal layer 33 is made of, for example, aluminum, copper, or stainless steel. The material of the first resin layer 34 is, for example, polypropylene, polyethylene, or polyamide. The material of the first resin layer 34 may be selected from the same type of material as the sealant 20 from the viewpoint of adhesion to the sealant 20. The material of the second resin layer 35 is, for example, polyethylene terephthalate or nylon. As an example, the laminate film 30L is an aluminum laminate film, and polypropylene may be selected as the first resin layer 34, aluminum as the metal layer 33, and polyethylene terephthalate as the second resin layer 35.

[0045] The container 30 has a first member 31 and a second member 32. The first member 31 is formed in a box shape with one end open. More specifically, the first member 31 includes an integrally formed side wall portion 31a, a flange portion 31b, and a bottom wall portion 31f. The side wall portion 31a is a rectangular cylindrical portion extending along the Z direction. The bottom wall portion 31f is a rectangular flat portion connected to one end of the side wall portion 31a in the Z direction. In the first member 31, a rectangular parallelepiped recess 31c is formed by the side wall portion 31a and the bottom wall portion 31f. The battery body 1A is housed in this recess 31c. The flange portion 31b is a rectangular frame-shaped portion connected to the end of the side wall portion 31a opposite to the bottom wall portion 31f and extending away from the recess 31c (outward).

[0046] In the bottom wall portion 31f, the first resin layer 34 and the second resin layer 35 are removed in a region that overlaps with the active material layer (positive electrode active material layer 16 and negative electrode active material layer 17) when viewed from the Z direction, and the metal layer 33 is exposed. In this embodiment, the portion of the bottom wall portion 31f of the first member 31 in which the metal layer 33 is exposed is in contact with the current collector 15 of the positive electrode terminal electrode 13, and an electrical connection is made. The first member 31 as described above can be formed, for example, by pressing a mold onto a base material of a flat laminate film 30L to form a recess 31c (for example, by embossing or drawing).

[0047] The second member 32 is provided to seal the recess 31c of the first member 31. The second member 32 may have the same shape as the first member 31, or it may be a flat sheet without a recess like the first member 31. In this embodiment, the second member 32 is a flat sheet without a recess like the first member 31. More specifically, the second member 32 includes a lid portion 32a and a joint portion 32b. The lid portion 32a is a rectangular flat portion that is positioned to overlap the recess 31c of the first member 31 when viewed from the Z direction. The joint portion 32b is a rectangular frame-shaped portion that extends from the lid portion 32a away from the recess 31c (outward).

[0048] In the lid portion 32a, the first resin layer 34 and the second resin layer 35 have been removed in a region that overlaps with the active material layer (positive electrode active material layer 16 and negative electrode active material layer 17) when viewed from the Z direction, exposing the metal layer 33. In this embodiment, the portion of the lid portion 32a of the second member 32 in which the metal layer 33 is exposed is in contact with the current collector 15 of the negative electrode terminal electrode 12, and an electrical connection is made.

[0049] The joint portion 32b is formed in the same shape as the flange portion 31b of the first member 31 and is superimposed on the flange portion 31b. The first member 31 and the second member 32 are integrated by joining the superimposed flange portions 31b and joint portion 32b (for example, by welding). This seals the space (recess 31c) in which the battery body 1A is housed. The container 30 is in close contact with the battery body 1A by allowing exhaust from the recess 31c in the state in which the battery body 1A is housed. In addition, any wiring, such as voltage detection lines connected to each of the current collectors 15, may be led to the outside through the joint portion between the flange portion 31b and the joint portion 32b.

[0050] Next, an embodiment of a method for manufacturing the energy storage module 1 described above will be explained. Figures 2 to 7 show a step in the energy storage module manufacturing method according to this embodiment. In this manufacturing method, first, as shown in Figure 2, a plurality of electrode units are prepared, each including an electrode (bipolar electrode 11, negative terminal electrode 12, positive terminal electrode 13) containing a current collector 15, and a sealing material 21 provided on the peripheral edge 15c of the current collector 15 (first step).

[0051] More specifically, first, an electrode unit A1 is manufactured as shown in Figure 2(a) (step S101, first step). In step S101, multiple bipolar electrodes 11 are prepared, and a frame-shaped sealing material 21 is provided on the peripheral edge 15c of one side 15a and the other side 15b of the current collector 15 of each of the multiple bipolar electrodes 11, thereby manufacturing multiple electrode units A1.

[0052] Furthermore, as shown in Figure 2(b), an electrode unit A2 is manufactured (step S102, first step). In step S102, one negative terminal electrode 12 is prepared, and a frame-shaped sealing material 21 is provided on the peripheral edges 15c of one side 15a and the other side 15b of the current collector 15 of the negative terminal electrode 12, thereby manufacturing the electrode unit A2.

[0053] Furthermore, as shown in Figure 2(c), an electrode unit A3 is fabricated (step S103, first step). In step S103, one positive terminal electrode 13 is prepared, and a frame-shaped sealing material 21 is provided on the peripheral edges 15c of one side 15a and the other side 15b of the current collector 15 of the positive terminal electrode 13, thereby fabricating the electrode unit A3. Note that the order of steps S101, S102, and S103 is arbitrary.

[0054] In the subsequent step, as shown in Figure 3, one electrode unit A3, multiple electrode units A1, and one electrode unit A2 are stacked in this order with spacers 22 interposed between each sealing material 21 (step S104, second step). This forms an electrode stack 10 (first stack) containing multiple electrodes, and a resin stack 20A (second stack) containing multiple sealing materials 21 and multiple spacers 22, which surrounds the electrode stack 10. The resin stack 20A is the part that will later become the sealant 20. In step S104, the electrode units A1 to A3 are stacked such that separators 14 are placed between adjacent electrode units A1 to A3 in the resin stack 20A.

[0055] Next, the resin laminate 20A is restrained. More specifically, the resin laminate 20A is restrained by a pair of restraining members 52 positioned on both sides of the resin laminate 20A in the Z direction. At this time, the region of the electrode laminate 10 that overlaps with the positive electrode active material layer 16 and the negative electrode active material layer 17 when viewed from the Z direction may be restrained by a pair of restraining members 51 positioned on both sides of the electrode laminate 10 in the Z direction. Furthermore, the restraining members 51 and 52 may be integrated.

[0056] As shown in Figure 3, the electrode laminate 10 may have a thickness in the Z-direction greater than the thickness in the Z-direction of the region constrained by the restraining member 51, i.e., the region of the electrode laminate 10 that overlaps with the positive electrode active material layer 16 and the negative electrode active material layer 17 when viewed from the Z-direction. In other words, at both ends of the electrode laminate 10 in the Z-direction, the current collector 15 of the negative electrode terminal electrode 12 and the current collector 15 of the positive electrode terminal electrode 13 may protrude in the Z-direction greater than the resin laminate 20A. In this case, when the container 30 is in close contact with the battery body 1A in a later step, contact can be suitably formed between the current collector 15 of the negative electrode terminal electrode 12 and the current collector 15 of the positive electrode terminal electrode 13 and the metal layer 33 exposed from the first resin layer 34 and the second resin layer 35.

[0057] In the subsequent step, as shown in Figures 4 and 5, the outer edges of the sealant 21 and spacer 22 (i.e., the resin laminate 20A) are cut off when viewed from the Z direction (step S105, third step). This eliminates the lamination misalignment and dimensional tolerances of the sealant 21 and spacer 22, and ensures the flatness of the outer surface of the resin laminate 20A extending in the Z direction. At this time, the corners 20r (first corner) of the resin laminate 20A when viewed from the Z direction are cut off (chamfered) so that they have chamfered portions 20p. Here, chamfering is performed on all of the multiple (four) corners 20r. The chamfered portion 20p may be a C-surface or a R-surface. In this embodiment, the chamfered portion 20p is an R-surface.

[0058] Next, as shown in Figure 6, a sealant 20 for sealing the internal space S formed between the electrodes is formed from the resin laminate 20A by welding adjacent sealing materials 21 and spacers 22 in the Z direction (step S106, third step). More specifically, in step S106, welded ends 23 are formed by welding the ends of the multiple sealing materials 21 opposite to the internal space S and the ends of the multiple spacers 22 opposite to the internal space S. This forms the sealant 20 from the resin laminate 20A. A battery body 1A including the electrode laminate 10 and the sealant 20 is then constructed.

[0059] Since the resin laminate 20A is chamfered in step S105, the sealant 20 has chamfered portions 20p at the corners 20r when viewed from the Z direction. Therefore, in steps S105 and S106, the sealant 20 is formed such that, when viewed from the Z direction, the corners 20r of the sealant 20 have chamfered portions 20p. In particular, in this embodiment, after chamfering the corners of each of the multiple sealing materials 21 and multiple spacers 22 stacked in the Z direction (i.e., the corners 20r of the resin laminate 20A) in step S105, the sealing materials 21 and spacers 22 are welded together in step S106, resulting in the sealant 20 being formed such that the corners 20r have chamfered portions 20p. Therefore, when viewed from the Z direction, the battery body 1A has chamfered portions 20p at the corners 20r of the sealant 20.

[0060] In the next step, as shown in Figure 7, the battery assembly 1A, which includes the electrode stack 10 and the sealant 20, is housed in a container 30 made of a laminate film 30L (step S107, fourth step). More specifically, in step S107, the battery assembly 1A is housed in the recess 31c of the first member 31 of the container 30, and the recess 31c is sealed with the second member 32.

[0061] Here, when the battery body 1A is housed in the container 30 (first member 31), the corner 30r (second corner) facing the corner 20r of the sealing body 20 is provided with a chamfered shape. This is because, for example, when the first member 31 is formed by embossing, if the edge of the press die used for embossing has a chamfered portion, the shape corresponding to the chamfered portion of the press die (chamfered shape) is transferred to and formed on the corner 30r of the first member 31. Therefore, if the edge of the press die has an R-shaped chamfered portion, an R-shaped chamfered shape is formed on the corner 30r, and if the edge of the press die has a C-shaped chamfered portion, a C-shaped chamfered shape is formed on the corner 30r. For example, if the chamfered portion 20p of the corner 20r of the sealing body 20 is an R-shaped surface, then an R-shaped chamfered shape can be formed on the corner 30r of the container 30. Similarly, if the chamfered portion 20p of the corner 20r of the sealing body 20 is a C-shaped surface, then a C-shaped chamfered shape can be formed on the corner 30r of the container 30. In this way, a chamfered shape corresponding to (complementary) the shape of the chamfered portion 20p of the corner 20r of the sealing body 20 can be formed on the corner 30r of the container 30. That is, the chamfered shape of the corner 30r can be the same type of shape as the chamfered portion 20p, whichever is the R-shaped or C-shaped surface. In this embodiment, both the chamfered portion 20p of the corner 20r and the chamfered shape of the corner 30r are R-shaped surfaces.

[0062] The size of the chamfered portion 20p of the corner 20r of the sealing body 20 is set to be greater than or equal to the size of the chamfered shape of the corner 30r of the container 30 (they may be the same). If the chamfered portion 20p of the corner 20r and the chamfered shape of the corner 30r are R-shaped, then for the chamfered portion 20p of the corner 20r to be larger than the chamfered shape of the corner 30r means, for example, that the radius of curvature of the chamfered portion 20p of the corner 20r is greater than or equal to the radius of curvature of the chamfered shape of the corner 30r. Also, if the chamfered portion 20p of the corner 20r and the chamfered shape of the corner 30r are C-shaped, then for the chamfered portion 20p of the corner 20r to be larger than the chamfered shape of the corner 30r means, for example, that the length of one side of the chamfered portion 20p (C-shaped) of the chamfered portion 20p of the corner 20r is greater than or equal to the length of one side of the chamfered shape of the corner 30r.

[0063] Subsequently, the container 30 is evacuated and depressurized to bring it into close contact with the battery body 1A (step S108, fifth step). At this time, the corner portion 20r of the sealant 20 having a chamfered portion 20p on the battery body 1A comes into close contact with the corner portion 30r of the container 30. As a result, the energy storage module 1 is obtained as shown in Figure 1.

[0064] As described above, in the energy storage module manufacturing method according to this embodiment, first, a plurality of electrode units A1, A2, A3, each including an electrode and a sealing material 21 welded to the electrode, are stacked with spacers 22 interposed between the sealing materials 21. This constitutes an electrode stack 10 including a plurality of electrodes and a resin stack 20A including a plurality of sealing materials 21 and a plurality of spacers 22. Next, by welding adjacent sealing materials 21 and spacers 22 in the stacking direction (Z direction, first direction), a sealing body 20 having the function of sealing the internal space S formed between the electrodes is formed from the resin stack 20A. This constitutes a battery body 1A having an electrode stack 10 and a sealing body 20 surrounding the electrode stack 10. Then, an energy storage module 1 is obtained by housing the battery body 1A in a container 30 made of laminate film 30L.

[0065] In the energy storage module manufacturing method according to this embodiment, when forming the sealant 20, the corners 20r of the sealant 20 are made to have chamfered portions 20p when viewed from the Z direction. Therefore, damage to the metal layer 33 of the laminate film 30L when the corners 20r of the sealant 20 come into contact with the laminate film 30L is suppressed, and the reliability of the energy storage module 1 is improved.

[0066] In particular, in the energy storage module manufacturing method according to this embodiment, a sealing body 20 is used that is integrally formed with the electrode stack 10 and has the function of sealing the electrode stack 10, in order to suppress damage to the metal layer 33 of the laminate film 30L and improve the reliability of the energy storage module 1. Therefore, in order to suppress damage to the container made of laminate film, it is not necessary to house a spacer, which is configured as a separate component from the battery body and has a certain size, together with the battery body in the container. As a result, in this embodiment, the proportion of the volume of the container 30 occupied by the battery body 1A can be increased, and the decrease in the volumetric energy density of the energy storage module is suppressed.

[0067] Furthermore, in the energy storage module manufacturing method according to this embodiment, in steps S105 and S106, the sealing body 20 is formed such that the corners 20r have chamfered portions 20p after the corners 20r of the sealing material 21 and the spacer 22 are chamfered and then welded together. Thus, in this embodiment, the sealing material 21 and the spacer 22 are chamfered before the sealing body 20 is formed by welding the sealing material 21 and the spacer 22 together, and then the chamfered corners of the sealing material 21 and the chamfered corners of the spacer 22 are welded together. As a result, the width of the welded portion at the corner 20r of the sealing body 20 can be sufficiently secured, and the degree of freedom in chamfering the corner 20r is improved. That is, even if the size of the chamfered portion at the corner 20r is increased by increasing the radius of curvature when chamfering the corner 20r with an R chamfer, the sealing performance of the sealing body 20 is sufficiently ensured.

[0068] Furthermore, in the energy storage module manufacturing method according to this embodiment, the container 30 includes a first member 31 having a recess 31c formed therein and a second member 32 that seals the recess 31c. Then, in step S107, the battery body 1A is housed in the recess 31c and the recess 31c is sealed by the second member 32. In this case, a recess 31c with a depth capable of housing the battery body 1A is formed in one of the members constituting the container 30 (the first member 31).

[0069] Thus, when forming a deeper recess 31c in the laminate film 30L compared to the case where recesses are provided in both components constituting the container 30, for example, the edges of the embossing press die may be significantly chamfered to suppress damage to the laminate film 30L during manufacturing, and a chamfered shape may be formed on the corner 30r of the recess 31c. Therefore, in order to avoid the right-angle corner of the contents of the recess 31c coming into contact with the chamfered corner 30r, it is more effective to provide a chamfered portion 20p on the corner 20r of the sealant 20 as described above, thereby suppressing damage to the metal layer 33 of the laminate film 30L.

[0070] Furthermore, the energy storage module manufacturing method according to this embodiment includes a step S108 after step S107 in which the pressure inside the container 30 is reduced. In addition, the corner 30r that faces the corner 20r of the sealing body 20 when the battery body 1A is housed in the container 30 has a chamfered shape. The chamfered shape of the corner 30r corresponds to the shape of the chamfered portion 20p of the corner 20r. The size of the chamfered portion 20p of the corner 20r is greater than or equal to the size of the chamfered shape of the corner 30r. In this case, when the battery body 1A is housed in the container 30, the amount of gap between the battery body 1A and the container 30 can be reduced in most areas other than the facing portion where the corner 20r of the battery body 1A and the corner 30r of the container 30 face each other. More specifically, for example, by making the radius of curvature of the chamfered portion 20p of the corner 20r on the battery body 1A side larger than the radius of curvature of the chamfered shape of the corner 30r on the container 30 side, the amount of gap between the battery body 1A and the container 30 can be reduced in most areas other than the opposing portions where the corners 20r of the battery body 1A and the corners 30r of the container 30 face each other (for example, the edges connecting adjacent corners of the battery body 1A and the container 30 facing those edges). As a result, deformation of the laminate film 30L, such as the formation of wrinkles in the laminate film 30L, becomes less likely when the pressure inside the container 30 is reduced. Furthermore, by reducing the amount of gap between the container 30 and the battery body 1A, the decrease in the volume density of the battery can also be suppressed.

[0071] Here, the energy storage module 1 according to this embodiment includes a battery body 1A having an electrode stack 10 including a current collector 15 and a plurality of electrodes stacked in the Z direction, and a cylindrical sealant 20 provided so as to surround the electrode stack 10 and for sealing the internal space S formed between the electrodes, and a container 30 made of a laminate film 30L including a metal layer 33, which houses the battery body 1A. The sealant 20 has a plurality of sealing materials 21 provided on the peripheral edge 15c of each current collector 15 of the plurality of electrodes, a plurality of spacers 22 interposed between adjacent sealing materials 21, and a welded end 23 formed by welding the end of the plurality of sealing materials 21 opposite to the internal space S and the end of the plurality of spacers 22 opposite to the internal space S. When viewed from the Z direction, the corners 20r of the sealant 20 have chamfered portions 20p.

[0072] Thus, in the energy storage module 1 according to this embodiment, the corners 20r of the sealant 20 have chamfered portions 20p. Therefore, damage to the metal layer 33 of the laminate film 30L when the corners 20r of the sealant 20 come into contact with the laminate film 30L is suppressed, and the reliability of the energy storage module 1 is improved. Furthermore, in order to suppress damage to the metal layer 33 of the laminate film 30L and improve the reliability of the energy storage module 1, the energy storage module 1 utilizes a sealant 20 that is integrally formed with the electrode stack 10 and has the function of sealing the electrode stack 10. Therefore, in order to suppress damage to the container made of laminate film, it is not necessary to house a spacer, which is configured as a separate component from the battery body and has a certain size, together with the battery body inside the container. As a result, in this embodiment, the proportion of the volume of the container 30 that the battery body 1A occupies can be increased, and the decrease in the volumetric energy density of the energy storage module is suppressed.

[0073] The above embodiments describe one aspect of the present invention. Therefore, the present invention is not limited to the above embodiments and can be modified as needed.

[0074] For example, in the above embodiment, after chamfering the corners of the sealing material 21 and the spacer 22 in step S105, the sealing material 21 and the spacer 22 were welded together in step S106 to form a sealant 20 having a chamfered portion 20p at the corner 20r. However, the order of chamfering and welding may be reversed.

[0075] In other words, in this case, as shown in Figure 8, in step S106, a sealant 20 for sealing the internal space S formed between electrodes is formed from the resin laminate 20A by welding adjacent sealant 21 and spacer 22 in the Z direction. Then, in step S105, the corners 20r of the sealant 20 are chamfered to form chamfered portions 20p. In this case, since the chamfering of the corners 20r is performed after the sealant 20 is formed, the dimensional accuracy of the chamfered portions 20p is more reliably ensured. Note that the chamfering may also be performed on the corners of the sealant 20 when viewed from a direction intersecting the Z direction (lamination direction), i.e., on the corners of the sealant 20 in the lamination direction.

[0076] Furthermore, in the above embodiment, the container 30 was described as being composed of a bottomed box-shaped first member 31 having a recess 31c and a flat second member 32 that seals the recess 31c (i.e., a one-sided embossed form). However, in the container 30, both the first member 31 and the second member 32 may be formed in a bottomed box shape having a recess (i.e., a double-sided embossed form). Figure 9 is a schematic cross-sectional view showing a modified energy storage module.

[0077] In the modified example shown in Figure 9, the second member 32 includes an integrally formed side wall portion 32k, a flange portion 32p, and a bottom wall portion 32f. The side wall portion 32k is a rectangular cylindrical portion extending along the Z direction. The bottom wall portion 32f is a rectangular flat portion connected to one end of the side wall portion 32k in the Z direction. In the second member 32, a rectangular parallelepiped recess 32c is formed by the side wall portion 32k and the bottom wall portion 32f. The flange portion 32p is a rectangular frame-shaped portion connected to the end of the side wall portion 32k opposite to the bottom wall portion 32f, and extending away from the recess 32c (outward).

[0078] In the bottom wall portion 32f, at least in the area overlapping with the active material layers (positive electrode active material layer 16 and negative electrode active material layer 17) when viewed from the Z direction, the first resin layer 34 and the second resin layer 35 are removed, exposing the metal layer 33. In the modified example shown in Figure 9, the exposed portion of the metal layer 33 in the bottom wall portion 32f of the second member 32 is in contact with the current collector 15 of the negative electrode terminal electrode 12, and an electrical connection is made. Such a second member 32 can be formed, for example, by pressing a mold onto a base material of a flat laminate film 30L to form a recess 32c (for example, by embossing or drawing).

[0079] The flange portion 32p is formed in the same shape as the flange portion 31b of the first member 31 and is superimposed on the flange portion 31b. The first member 31 and the second member 32 are integrated by joining the superimposed flange portions 31b and 32p (for example, by welding). As a result, a space for housing the battery body 1A is formed by the mutually continuous recesses 31c and 32c, and this space is sealed. At this time, the sealing portion (flange portions 31b and 32p) of the container 30 is positioned midway in the Z direction of the energy storage module 1 (for example, near the center). The inside of the container 30 may also be depressurized during sealing.

[0080] Thus, in the modified example shown in Figure 9, a portion of the battery body 1A in the Z direction is housed in the recess 32c of the second member 32, and the remaining portion of the battery body 1A in the Z direction is housed in the recess 31c of the first member 31. Here, the recesses 31c of the first member 31 and the second member 32 in the modified example shown in Figure 9 are formed to have a shallower recess depth than the recess 31c of the first member 31 in the embodiment shown in Figure 1. With this modified example, the recesses 31c and 32c for housing the battery body 1A become shallower, which makes it easier to manufacture the container 30 by, for example, embossing, and also makes it possible to make the metal layer 33 of the base laminate film 30L thinner.

[0081] Figure 10 is a schematic cross-sectional view showing an energy storage device constructed by stacking the energy storage modules shown in Figure 9. As shown in Figure 10, the energy storage device 100 is constructed by stacking multiple (in this case, four) energy storage modules 1 shown in Figure 9. The stacking direction of the energy storage modules 1 is the same as the stacking direction (Z direction) of the electrodes in the electrode stack 10 of each energy storage module 1. A conductive member 40, as described above, is interposed between adjacent energy storage modules 1. The conductive member 40 is electrically connected to the current collector 15 of the positive terminal electrode 13 of the energy storage module 1 via the metal layer 33 of the container 30 of the energy storage module 1 on one side in the Z direction, and is electrically connected to the current collector 15 of the negative terminal electrode 12 of the energy storage module 1 via the metal layer 33 of the container 30 of the energy storage module 1 on the other side in the Z direction.

[0082] As a result, in the energy storage device 100, multiple energy storage modules 1 stacked in the Z direction are electrically connected in series. At both ends of the energy storage device 100 in the Z direction, the current collectors 15 of the outermost electrodes of the energy storage modules 1 are electrically connected to another conductive member 110 via the metal layer 33 of the container 30. The energy storage device 100 can be connected to the outside via the conductive members 110. Note that all of the multiple (in this case, three) conductive members 40 may have cooling channels formed therein to provide a cooling function, or some of the multiple conductive members 40 (for example, the central one of the three conductive members 40) may be formed in a solid shape and not have cooling channels.

[0083] Furthermore, in the above embodiment, the laminate film 30L constituting the container 30 had a metal layer 33, a first resin layer 34, and a second resin layer 35. In the above embodiment, the first resin layer 34 and the second resin layer 35 were removed in the region overlapping the active material layer of the first member 31 and the second member 32, exposing the metal layer 33, thereby forming an electrical connection between the conductive member 40 and the battery body 1A inside the container 30 via the metal layer 33 that was in contact with the current collector 15.

[0084] However, the configuration of the laminate film 30L is not limited to the above embodiment, and at least one of the first resin layer 34 and the second resin layer 35 may be omitted. Also, when forming an electrical connection between the conductive member 40 and the battery body 1A inside the container 30, the metal layer 33 may be exposed over a wider area, such as the entire bottom wall portion 31f of the first member 31 or the entire lid portion 32a of the second member 32. Alternatively, no such exposed portion of the metal layer 33 may be formed.

[0085] Furthermore, exhaust and depressurization of the container 30 in step S108 of the above embodiment is not essential.

[0086] The embodiments described above are described below.

[0087] [Note 1] A method for manufacturing an energy storage module, comprising: a first step of preparing a plurality of electrode units, each including an electrode including a current collector and a sealing material provided on the periphery of the current collector; a second step of stacking the plurality of electrode units in a first direction with frame-shaped spacers interposed between the sealing materials, after the first step, to form a first laminate including a plurality of electrodes and a second laminate including a plurality of sealing materials and a plurality of spacers, which is provided so as to surround the first laminate; a third step of forming a sealant from the second laminate to seal the internal space formed between the electrodes by welding adjacent sealing materials and spacers in the first direction, after the second step; and a fourth step of housing a battery body including the first laminate and the sealant in a container made of a laminate film including a metal layer, wherein in the third step, the sealant is formed such that the first corner, which is the corner of the sealant when viewed from the first direction, has a chamfered portion.

[0088] [Note 2] The method for manufacturing an energy storage module according to Note 1, wherein in the third step, the sealing body is formed such that the first corner has a chamfered portion by chamfering the corners of the sealing material and the spacer and then welding the sealing material and the spacer together.

[0089] [Note 3] The method for manufacturing an energy storage module according to Note 1, wherein in the third step, the sealing material and the spacer are welded together to form the sealing body, and then a chamfered portion is formed on the first corner.

[0090] [Note 4] The method for manufacturing an energy storage module according to any one of Notes 1 to 3, wherein the container includes a first member having a recess formed therein and a second member that seals the recess, and in the fourth step, the battery body is housed in the recess and the recess is sealed by the second member.

[0091] [Note 5] A method for manufacturing an energy storage module according to any one of Notes 1 to 4, further comprising a fifth step of reducing the pressure inside the container after the fourth step, wherein the second corner facing the corner of the sealing body when the battery body is housed in the container has a chamfered shape, the chamfered shape of the second corner corresponds to the shape of the chamfered portion of the first corner, and the size of the chamfered portion of the first corner is greater than or equal to the size of the chamfered shape of the second corner. [Explanation of symbols]

[0092] 1...Energy storage module, 1A...Battery body, 10...Electrode laminate (first laminate), 11...Bipolar electrode (electrode), 12...Negative terminal electrode (electrode), 13...Positive terminal electrode, 15...Current collector, 20...Sealant, 20A...Resin laminate (second laminate), 20r...Corner (first corner), 20p...Chamfered part, 21...Sealing material, 22...Spacer, 23...Welded end, 30...Container, 30L...Laminate film, 30r...Corner (second corner), 31...First component, 31c...Recess, 32...Second component, 33...Metal layer.

Claims

1. A first step involves preparing a plurality of electrode units, each including an electrode containing a current collector and a sealing material provided on the periphery of the current collector. A second step is to stack a plurality of electrode units in a first direction while interposing frame-shaped spacers between the sealing materials, thereby constructing a first laminate containing a plurality of electrodes and a second laminate containing a plurality of sealing materials and a plurality of spacers, which is provided to surround the first laminate. A third step is to form a sealing body from the second laminate for sealing the internal space formed between the electrodes by welding the sealing material and the spacer adjacent to each other in the first direction, after the second step, A fourth step is to house the battery assembly, which includes the first laminate and the seal, in a container made of a laminate film including a metal layer, after the third step. Equipped with, In the third step, the sealing body is formed such that the first corner, which is the corner of the sealing body when viewed from the first direction, has a chamfered portion. The container includes a first member having a recess formed therein and a second member that seals the recess. In the fourth step, the battery body is housed in the recess and the recess is sealed with the second member. Method for manufacturing energy storage modules.

2. In the third step, the sealing body is formed such that the first corner has a chamfered portion after the corners of the sealing material and the spacer are chamfered and then the sealing material and the spacer are welded together. A method for manufacturing an energy storage module according to claim 1.

3. In the third step, after welding the sealing material and the spacer to form the sealing body, a chamfered portion is formed on the first corner. A method for manufacturing an energy storage module according to claim 1.

4. The fourth step is followed by a fifth step of reducing the pressure inside the container, When the battery body is housed in the container, the second corner facing the corner of the sealing body has a chamfered shape. The chamfered shape of the second corner corresponds to the shape of the chamfered portion of the first corner. The size of the chamfered portion of the first corner is greater than or equal to the size of the chamfered shape of the second corner. A method for manufacturing an energy storage module according to any one of claims 1 to 3.

5. A first step of preparing a plurality of electrode units, each including an electrode with a current collector and a sealing material provided on the periphery of the current collector, A second step is to stack a plurality of electrode units in a first direction while interposing frame-shaped spacers between the sealing materials, thereby constructing a first laminate containing a plurality of electrodes and a second laminate containing a plurality of sealing materials and a plurality of spacers, which is provided to surround the first laminate. A third step is to form a sealing body from the second laminate for sealing the internal space formed between the electrodes by welding the sealing material and the spacer adjacent to each other in the first direction, after the second step, A fourth step is to house the battery assembly, which includes the first laminate and the seal, in a container made of a laminate film including a metal layer, after the third step. Equipped with, In the third step, the sealing body is formed such that the first corner, which is the corner of the sealing body when viewed from the first direction, has a chamfered portion. The fourth step is followed by a fifth step of reducing the pressure inside the container, When the battery body is housed in the container, the second corner facing the corner of the sealing body has a chamfered shape. The chamfered shape of the second corner corresponds to the shape of the chamfered portion of the first corner. The size of the chamfered portion of the first corner is greater than or equal to the size of the chamfered shape of the second corner. Method for manufacturing energy storage modules.

6. A first step of preparing a plurality of electrode units, each including an electrode with a current collector and a sealing material provided on the periphery of the current collector, A second step is to stack a plurality of electrode units in a first direction while interposing frame-shaped spacers between the sealing materials, thereby constructing a first laminate containing a plurality of electrodes and a second laminate containing a plurality of sealing materials and a plurality of spacers, which is provided to surround the first laminate. A third step is to form a sealing body from the second laminate for sealing the internal space formed between the electrodes by welding the sealing material and the spacer adjacent to each other in the first direction, after the second step, A fourth step is to house the battery assembly, which includes the first laminate and the seal, in a container made of a laminate film including a metal layer, after the third step. Equipped with, In the third step, the sealing body is formed such that the first corner, which is the corner of the sealing body when viewed from the first direction, has a chamfered portion. In the second step, at both ends of the first laminate in the first direction, the current collectors of the electrodes are made to protrude further in the first direction than the second laminate. Method for manufacturing energy storage modules.

7. A battery body comprising: a first laminate including a current collector and a plurality of electrodes stacked in a first direction; and a cylindrical seal provided so as to surround the first laminate and for sealing the internal space formed between the electrodes; A container comprising a laminate film containing a metal layer, which houses the battery assembly, Equipped with, The aforementioned encapsulant is Multiple sealing materials provided on the periphery of each of the current collectors of the multiple electrodes, Multiple spacers interposed between adjacent sealing materials, A welded end is formed by welding together the ends of the multiple sealing materials opposite to the internal space and the ends of the multiple spacers opposite to the internal space, It has, The first corner of the sealing body, as viewed from the first direction, has a chamfered portion. At both ends of the first laminate in the first direction, the current collector of the electrode protrudes in the first direction more than the sealing body. Energy storage module.

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