JP2024120645A - Energy storage module manufacturing method and energy storage module - Google Patents

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

This disclosure relates to a method for manufacturing an energy storage module and an energy storage module.

Patent Document 1 describes a laminated exterior battery. This battery includes a rectangular plate-shaped electrode group, a rectangular frame-shaped spacer, and a laminate exterior body that houses them together with a nonaqueous electrolyte. The laminate exterior body has a first metal laminate film member having a storage recess. A spacer, which is a separate member, is attached to the outer circumferential surface of the electrode group so as to be interposed between the outer circumferential surface of the electrode group and the inner surface of the storage recess.

JP 2020-140874 A

However, in a power storage device that houses a laminated exterior body made of a laminate film member and a stack of electrodes or the like that are rectangular in plan view, there is a problem that the laminated exterior body is damaged when the right-angled corners of the stack come into contact with the laminated film member. 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 housed inside the laminated exterior body, thereby suppressing damage to the laminated exterior body due to contact with the corners of the electrode group.

However, the battery described in Patent Document 1 has a problem in that the volumetric energy density of the battery is reduced because a spacer is used as a separate member from the electrode group to prevent damage to the laminated exterior body.

Therefore, the present disclosure aims 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.

The method for manufacturing an electric storage module according to the present disclosure includes a first step of preparing a plurality of electrode units each including an electrode including a collector and a sealing material provided on the periphery of the collector; a second step of stacking the plurality of electrode units in a first direction with a frame-shaped spacer 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 and provided to surround the first laminate; a third step of forming a sealing body from the second laminate by welding the sealing materials and the spacers adjacent in the first direction to seal the internal space formed between the electrodes; and a fourth step of housing a battery body including the first laminate and the sealing body in a container formed of a laminate film including a metal layer after the third step, and in the third step, the sealing body is formed so that a first corner portion, which is a corner portion of the sealing body when viewed from the first direction, has a chamfered portion.

In this manufacturing method, first, a plurality of electrode units each including an electrode and a sealing material welded to the electrode are stacked with a spacer between the sealing materials. This results in an electrode stack (first stack) including a plurality of electrodes, and a second stack including a plurality of sealing materials and a plurality of spacers. Next, adjacent sealing materials and spacers in the stacking direction (first direction) are welded together to form a sealing body from the second stack that has the function of sealing the internal space formed between the electrodes. This results in a battery body including the electrode stack and the sealing body surrounding the electrode stack. The battery body is then housed in a container made of a laminate film to obtain a storage module.

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

In the energy storage module manufacturing method according to the present disclosure, in the third step, the corners of the sealant and the spacer may be chamfered and then the sealant and the spacer are welded to form a sealing body having a chamfered portion at the first corner. In this case, the sealant and the spacer are chamfered before the sealing body is formed by welding the sealant and the spacer. This ensures a more sufficient sealing distance (width of the welded portion) compared to when the welded portion is chamfered (removed) after the sealant and the spacer are welded.

In the energy storage module manufacturing method according to the present disclosure, in the third step, the sealing material and the spacer are welded together to form a sealing body, and then a chamfer is formed at the first corner. In this case, after the sealing body is formed, the corner (first corner) is chamfered. Therefore, the dimensional accuracy of the chamfer is more reliably ensured compared to when welding is performed after the sealing material and spacer are chamfered.

In the energy storage module manufacturing method according to the present disclosure, 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 may be housed in the recess and the recess may be sealed with the second member. In this way, when a deeper recess is formed in the laminate film compared to when recesses are provided in both members that make up the container, a chamfered shape may be formed in the second corner of the recess for manufacturing reasons. Therefore, in order to prevent the right-angle corner of the contents of the recess from 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 sealing body as described above and suppress damage to the metal layer of the laminate film.

The method for manufacturing an energy storage module according to the present disclosure includes a fifth step of reducing the pressure inside the container after the fourth step, and a second corner that faces 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 is a shape that corresponds to the shape of the chamfered portion of the first corner, and the size of the chamfered portion of the first corner may be equal to or larger than the size of the chamfered shape of the second corner. In this case, when the battery body is housed in the container, the amount of gap between the battery body and the container can be reduced. As a result, deformation of the laminate film, such as wrinkles occurring in the laminate film, is less likely to occur when the pressure inside the container is reduced.

The energy storage module according to the present disclosure includes a battery body having a first laminate including a current collector and including a plurality of electrodes stacked in a first direction, and a cylindrical sealing body arranged to surround the first laminate and seal the internal space formed between the electrodes, and a container that is composed of a laminate film including a metal layer and contains the battery body, and the sealing body has a plurality of sealing materials arranged on the periphery of each of the current collectors of the plurality of electrodes, a plurality of spacers interposed between adjacent sealing materials, and a welded end portion formed by welding the end portions of the plurality of sealing materials opposite the internal space to the end portions of the plurality of spacers opposite the internal space, and a first corner portion that is a corner portion of the sealing body when viewed from the first direction has a chamfered portion.

In this energy storage module, the corner (first corner) of the sealing body has a chamfered portion. This suppresses damage to the metal layer of the laminate film when the corner of the sealing body comes into contact with the laminate film, improving reliability. In addition, in this energy storage module, a sealing body that is formed integrally with the electrode stack and has the function of sealing the electrode stack is used to suppress damage to the metal layer of the laminate film and improve reliability. Therefore, in order to suppress damage to the container formed of the laminate film, the volume of the battery body contained in the container can be made larger than when a spacer is contained in the container as a separate member together with the battery body, and a decrease in the volumetric energy density of the energy storage module is suppressed.

The present disclosure provides 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.

FIG. 1 is a schematic cross-sectional view of an electricity storage module according to this embodiment. FIG. 2 is a diagram showing one step of the method for manufacturing the electricity storage module according to this embodiment. FIG. 3 is a diagram showing one step of the method for manufacturing the electricity storage module according to this embodiment. FIG. 4 is a diagram showing one step of the method for manufacturing the electricity storage module according to this embodiment. FIG. 5 is a diagram showing one step of the method for manufacturing the electricity storage module according to this embodiment. FIG. 6 is a diagram showing one step of the method for manufacturing the electricity storage module according to this embodiment. FIG. 7 is a diagram showing one step of the method for manufacturing the electricity storage module according to this embodiment. FIG. 8 is a diagram showing one step of a method for manufacturing an electricity storage module according to a modified example. FIG. 9 is a schematic cross-sectional view showing an electricity storage module according to a modified example in which both sides are embossed. FIG. 10 is a schematic cross-sectional view showing an electricity storage device formed by stacking the electricity storage modules shown in FIG.

The energy storage module according to one embodiment will be described below with reference to the drawings. In the description of each figure, the same or corresponding elements are given the same reference numerals, and duplicate descriptions may be omitted. In addition, each figure may show an orthogonal coordinate system that defines the X direction, the Y direction perpendicular to the X direction, and the Z direction perpendicular to the X and Y directions.

Figure 1 is a schematic cross-section of a storage module according to this embodiment. The storage module 1 shown in Figure 1 is a storage module used in batteries for various vehicles, such as forklifts, hybrid cars, and electric cars. The storage module 1 is a secondary battery, such as a nickel-metal hydride secondary battery or a lithium-ion secondary battery. The storage module 1 may be an electric double layer capacitor or an all-solid-state battery. Here, the case where the storage module 1 is a lithium-ion secondary battery is illustrated as an example.

The energy storage module 1 includes an electrode stack 10 (first stack) and a sealing body 20. The electrode stack 10 includes a plurality of electrodes stacked along the Z direction (first direction). The plurality of electrodes includes a plurality of bipolar electrodes 11, a negative terminal electrode 12, and a positive terminal electrode 13. Separators 14 are interposed between adjacent electrodes.

The bipolar electrode 11 has a current collector 15, a positive electrode active material layer 16, and a negative electrode active material layer 17. The current collector 15 is, for example, in the form of a rectangular sheet. The positive electrode active material layer 16 is provided on one surface 15a of the current collector 15. The negative electrode active material layer 17 is provided on the other surface 15b, which is the surface opposite to the one surface 15a of the current collector 15. The multiple bipolar electrodes 11 are stacked so that the positive electrode active material layer 16 of one bipolar electrode 11 faces the negative electrode active material layer 17 of another bipolar electrode 11. Here, one surface 15a of the current collector 15 faces one side of the Z direction (the direction from the positive electrode terminal electrode 13 toward the negative electrode terminal electrode 12 in FIG. 1), and the other surface 15b of the current collector 15 faces the other side of the Z direction (the direction from the negative electrode terminal electrode 12 toward the positive electrode terminal electrode 13 in FIG. 1).

The positive electrode active material layer 16 and the negative electrode active material layer 17 are rectangular 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 viewed from the Z direction, the entire formation area of the positive electrode active material layer 16 is located within the formation area of the negative electrode active material layer 17.

The negative electrode terminal electrode 12 has a current collector 15 and a negative electrode active material layer 17 provided on the other surface 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 surface 15a of the current collector 15. In other words, no active material layer is provided on one surface 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 so that the negative electrode active material layer 17 faces the positive electrode active material layer 16 of the bipolar electrode 11.

The positive electrode terminal electrode 13 has a current collector 15 and a positive electrode active material layer 16 provided on one surface 15a of the current collector 15. The positive electrode terminal electrode 13 does not have a positive electrode active material layer 16 or a negative electrode active material layer 17 on the other surface 15b, which is the surface opposite to the one surface 15a of the current collector 15. In other words, no active material layer is provided on the other surface 15b of the current collector 15 of the positive electrode terminal electrode 13. The positive electrode terminal electrode 13 is laminated on the bipolar electrode 11 at one end of the electrode laminate 10 in the Z direction. The positive electrode terminal electrode 13 is laminated on the bipolar electrode 11 so that the positive electrode active material layer 16 faces the negative electrode active material layer 17 of the bipolar electrode 11.

In this embodiment, the current collectors of the bipolar electrode 11, the negative terminal electrode 12, and the positive terminal electrode 13 are designated by the same reference numeral as the current collector 15, but 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.

The separators 14 are disposed between adjacent bipolar electrodes 11, between the negative terminal electrode 12 and the bipolar electrode 11, and between the positive terminal electrode 13 and the bipolar electrode 11. The separators 14 are interposed between the positive electrode active material layer 16 and the negative electrode active material layer 17. The separators 14 are members that allow 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, they prevent short circuits caused by contact between adjacent electrodes.

The current collector 15 is a chemically inactive electrical conductor for continuously passing a current through the positive electrode active material layer 16 and the negative electrode active material layer 17 during discharging 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 the conductive resin material include resins in which a conductive filler is added as necessary to a conductive polymer material or a non-conductive polymer material. The current collector 15 may have multiple layers. In this case, each layer of the current collector 15 may contain the above-mentioned metal material and/or conductive resin material.

A coating layer may be formed on the surface of the current collector 15. The coating layer may be formed by a known method such as plating or spray coating. The current collector 15 may be, for example, in the form of a plate, foil (e.g., metal foil), film, or mesh. Examples of metal foil include aluminum foil, copper foil, nickel foil, titanium foil, and stainless steel foil. The current collector 15 may be an alloy foil of the above metals or a foil in which multiple metal foils are integrated. When the current collector 15 is in the form of a foil, the thickness of the current collector 15 may be, for example, 1 μm to 200 μm. In this embodiment, the current collector 15 is a foil in which aluminum foil and copper foil are integrated, or an aluminum foil.

The positive electrode active material layer 16 contains a positive electrode active material capable of absorbing and releasing charge carriers such as lithium ions. Examples of the positive electrode active material include lithium composite metal oxides having a layered rock salt structure, metal oxides having a spinel structure, polyanion compounds, and the like. The positive electrode active material may be any material that can be used in lithium ion secondary batteries. The positive electrode active material layer 16 may contain a plurality of positive electrode active materials. In this embodiment, the positive electrode active material layer 16 contains olivine-type lithium iron phosphate (LiFePO ₄ ) as a composite oxide.

The negative electrode active material layer 17 contains a negative electrode active material capable of absorbing and releasing charge carriers such as lithium ions. The negative electrode active material may be any of a simple substance, an alloy, or a compound. Examples of the negative electrode active material include Li, carbon, and metal compounds. The negative electrode active material may be an element capable of being alloyed with lithium or a compound thereof. Examples of carbon include natural graphite, artificial graphite, hard carbon (hardly graphitizable carbon), and soft carbon (easily graphitizable carbon). Examples of artificial graphite include highly oriented graphite and mesocarbon microbeads. Examples of elements capable of being alloyed with lithium include silicon and tin. In this embodiment, the negative electrode active material layer 17 contains graphite as a carbon-based material.

Each of the positive electrode active material layer 16 and the negative electrode active material layer 17 (hereinafter sometimes simply referred to as "active material layer") may further contain, as necessary, a conductive assistant to increase electrical conductivity, a binder, an electrolyte (polymer matrix, ionically conductive polymer, electrolyte solution, etc.), an electrolyte supporting salt (lithium salt) to increase ionic conductivity, etc. The conductive assistant is added to increase the conductivity of each electrode (bipolar electrode 11, negative electrode terminal electrode 12, positive electrode terminal electrode 13). The conductive assistant is, for example, acetylene black, carbon black, graphite, etc.

Examples of binders include fluorine-containing resins 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), carboxymethyl cellulose, alginates such as sodium alginate and ammonium alginate, water-soluble cellulose ester crosslinked bodies, and starch-acrylic acid graft polymers. These binders may be used alone or in combination. Examples of the solvent for the binder include water and N-methyl-2-pyrrolidone (NMP).

The separator 14 may be, for example, a porous sheet or nonwoven fabric containing a polymer that absorbs and retains an electrolyte. Examples of materials for the separator 14 include polypropylene, polyethylene, polyolefin, polyester, and the like. The separator 14 may have a single-layer structure or a multi-layer structure. The multi-layer structure may have, 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 in the separator 14 is a liquid electrolyte (electrolytic solution) containing a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent.

The electrolyte salt of the electrolyte may be a known lithium salt such as LiClO ₄ , LiAsF ₆ , LiPF ₆ , LiBF ₄ , LiCF ₃ SO ₃ , LiN(FSO ₂ ) ₂ , or LiN(CF ₃ SO ₂ ) _2. The non-aqueous solvent may be a known solvent such as cyclic carbonates, cyclic esters, chain carbonates, chain esters, or ethers. Two or more of these known solvent materials may be used in combination.

The sealing body 20 is formed in a rectangular tube shape on the peripheral portion of the electrode stack 10 so as to surround the electrode stack 10 when viewed from the first direction D1. The sealing body 20 can be joined (welded) to each of the one surface 15a and the other surface 15b of the current collector 15 at the peripheral portion 15c of each current collector 15. The sealing body 20 forms an internal space S between the current collectors 15 adjacent in the Z direction and seals each of the internal spaces S. An electrolyte (e.g., an electrolyte solution) is contained in each internal space S. The sealing body 20 can prevent the electrolyte solution contained in the internal space S from flowing out to the outside. In addition, the sealing body 20 can prevent air, moisture, etc. from entering the internal space S from the outside of the electrode stack 10.

The edge of the separator 14 is joined to the sealing body 20. The sealing body 20 contains an insulating material. Examples of materials for the sealing body 20 include various resin materials such as polypropylene, polyethylene, polystyrene, ABS resin, acid-modified polypropylene, acid-modified polyethylene, and acrylonitrile-styrene resin.

The sealing body 20 includes a plurality of resin sealants 21 and a plurality of resin spacers 22. The sealants 21 are provided on each of the current collectors 15. Thus, the plurality of sealants 21 are stacked along the Z direction. The sealant 21 is frame-shaped (here, rectangular frame-shaped) when viewed from the Z direction, and is provided on the peripheral portion 15c of the current collector 15. The sealant 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 portion 15c. That is, the sealant 21 has an inner portion that overlaps with the current collector 15 and an outer portion that is located outside the edge of the current collector 15 on one surface 15a and the other surface 15b of the current collector 15, respectively, when viewed from the Z direction, and the outer portions of a pair of sealants 21 adjacent to each other across the current collector 15 are connected to each other. The inner portions of the seal material 21 can be welded to one surface 15a and the other surface 15b of the current collector 15. In this embodiment, the seal material 21 is welded to both the one surface 15a and the other surface 15b of the current collector 15.

In this embodiment, the seal material provided on each of 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 is given the same reference numeral as the seal material 21, but the seal material provided on the current collector 15 of the bipolar electrode 11, the seal material provided on the current collector 15 of the negative terminal electrode 12, and the seal material provided on the current collector 15 of the positive terminal electrode 13 may be the same as or different from each other.

The spacer 22 is disposed between the seal materials 21 adjacent in the Z direction. As a result, the spacer 22, together with a pair of seal materials 21 adjacent in the Z direction, maintains the distance between the collectors 15 adjacent in the Z direction. An internal space S is defined by a pair of collectors 15 adjacent in the Z direction, the spacer 22, and a pair of seal 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 disposed on the peripheral portion 15c of the collector 15 when viewed from the Z direction. The end of the separator 14 may be sandwiched and held between the seal material 21 and the spacer 22. The end of the separator 14 may be fixed by welding to at least one of the seal material 21 and the spacer 22.

A part of the end of the sealing materials 21 located outside the edge of the current collector 15 (a part of the end opposite the internal space S) and a part of the end of the spacers 22 located outside the edge of the current collector 15 (a part of the end opposite the internal space S) are welded together and integrated. That is, the sealing body 20 includes a welded end 23 formed by welding the ends of the sealing materials 21 and the ends of the spacers 22 together. The welded end 23 has a frame shape surrounding the electrode stack 10 when viewed from the Z direction, and constitutes the outer periphery of the sealing body 20. Therefore, the outer surface of the welded end 23 forms the outer surface of the sealing body 20. In this embodiment, the spacer 22 is not welded to the inner part of the sealing material 21 adjacent to it in the Z direction (the part overlapping the current collector 15 when viewed from the Z direction), but the spacers 22 and the part of the inner part of the sealing material 21 adjacent to each other may be welded.

In addition, the conductive member 40 is laminated on the other surface 15b of the current collector 15 of the negative terminal electrode 12 and the one surface 15a of the current collector 15 of the positive terminal electrode 13 exposed from the sealing body 20 via a metal layer 33 described later. The pair of conductive members 40 are 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 metal layer 33 having good electrical conductivity. The pair of conductive members 40 each function as a terminal for extracting current from the storage module 1. The conductive member 40 can be used to electrically connect multiple storage modules 1. The conductive member 40 can also be used as a member for applying a restraining load to the electrode stack 10. That is, when a restraining member (not shown) that restrains the storage module 1 from the Z direction is arranged, a restraining load is applied to the electrode stack 10 via the conductive member 40. Furthermore, a cooling flow path may be formed in the conductive member 40. The energy storage module 1 can be cooled by circulating a cooling medium through the cooling flow path formed in the conductive member 40.

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

The container 30 is composed 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 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.

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

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 side open. More specifically, the first member 31 includes a side wall portion 31a, a flange portion 31b, and a bottom wall portion 31f that are integrally formed. The side wall portion 31a is a rectangular tubular 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 accommodated in this recess 31c. The flange portion 31b is a rectangular frame-shaped portion that is connected to the end of the side wall portion 31a opposite the bottom wall portion 31f and extends away from the recess 31c (toward the outside).

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

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 may be a flat sheet-like member without a recess like the first member 31. In this embodiment, the second member 32 is a flat sheet-like member 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 arranged to overlap the recess 31c of the first member 31 when viewed from the Z direction. The joint portion 32b is a rectangular frame-like portion that extends from the lid portion 32a so as to move away from the recess 31c (toward the outside).

In the lid portion 32a, at least in the range overlapping with the active material layers (positive electrode active material layer 16 and negative electrode active material layer 17) as viewed from the Z direction, the first resin layer 34 and the second resin layer 35 are removed, and the metal layer 33 is exposed. In this embodiment, the portion where the metal layer 33 is exposed in the lid portion 32a 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 established.

The joint 32b is formed in the same shape as the flange 31b of the first member 31, and is overlapped on the flange 31b. The first member 31 and the second member 32 are integrated by joining (for example, by welding) the overlapping flange 31b and the joint 32b. 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 evacuating the recess 31c in which the battery body 1A is housed. Note that any wiring, such as a voltage detection line connected to each of the current collectors 15, may be led out to the outside through the joint between the flange 31b and the joint 32b.

Next, an embodiment of a method for manufacturing the above-mentioned storage module 1 will be described. FIGS. 2 to 7 are diagrams showing a step of the method for manufacturing the storage module according to this embodiment. In this manufacturing method, first, as shown in FIG. 2, a plurality of electrode units are prepared, each of which includes an electrode (bipolar electrode 11, negative terminal electrode 12, positive terminal electrode 13) including a current collector 15 and a seal material 21 provided on the peripheral portion 15c of the current collector 15 (first step).

More specifically, first, as shown in FIG. 2(a), an electrode unit A1 is fabricated (step S101, first step). In step S101, a plurality of bipolar electrodes 11 are prepared, and a frame-shaped seal material 21 is provided on the peripheral portion 15c of one surface 15a and the other surface 15b of the current collector 15 of each of the plurality of bipolar electrodes 11, thereby fabricating a plurality of electrode units A1.

As shown in FIG. 2B, an electrode unit A2 is fabricated (step S102, first step). In step S102, one negative terminal electrode 12 is prepared, and a frame-shaped seal material 21 is provided on the peripheral portion 15c of one surface 15a and the other surface 15b of the current collector 15 of the negative terminal electrode 12, thereby fabricating the electrode unit A2.

Furthermore, as shown in FIG. 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 seal material 21 is provided on the peripheral portion 15c of one surface 15a and the other surface 15b of the current collector 15 of the positive terminal electrode 13, to fabricate the electrode unit A3. Note that the order of steps S101, S102, and S103 is arbitrary.

In the next step, as shown in FIG. 3, one electrode unit A3, multiple electrode units A1, and one electrode unit A2 are stacked in this order with spacers 22 between the respective sealing materials 21 (step S104, second step). This results in an electrode laminate 10 (first laminate) including multiple electrodes, and a resin laminate 20A (second laminate) including multiple sealing materials 21 and multiple spacers 22 and provided to surround the electrode laminate 10. The resin laminate 20A is the part that will later become the sealing body 20. In step S104, the electrode units A1 to A3 are stacked so that separators 14 are arranged between adjacent electrode units A1 to A3 in the resin laminate 20A.

Next, the resin laminate 20A is restrained. More specifically, the resin laminate 20A is restrained by a pair of restraining members 52 arranged 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 as viewed from the Z direction may be restrained by a pair of restraining members 51 arranged on both sides of the electrode laminate 10 in the Z direction. The restraining members 51 and 52 may be integrated.

3, the electrode laminate 10 may have a thickness in the Z direction of the region restrained by the restraining member 51, i.e., the region overlapping the positive electrode active material layer 16 and the negative electrode active material layer 17 when viewed from the Z direction in the electrode laminate 10, greater than the thickness in the Z direction of the region restrained by the restraining member 52, i.e., the resin laminate 20A. 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 be in a state of protruding in the Z direction from the resin laminate 20A. In this case, when the container 30 is closely attached to the battery body 1A in a later process, the current collector 15 of the negative electrode terminal electrode 12 and the current collector 15 of the positive electrode terminal electrode 13 may be in contact with the metal layer 33 exposed from the first resin layer 34 and the second resin layer 35.

In the next step, as shown in Figs. 4 and 5, the outer periphery of the sealant 21 and the spacer 22 (i.e., the resin laminate 20A) when viewed from the Z direction is cut off (step S105, third step). This eliminates the lamination misalignment and dimensional tolerance of the sealant 21 and the spacer 22, and ensures the flatness of the outer surface of the resin laminate 20A extending in the Z direction. At this time, the corner 20r (first corner) of the resin laminate 20A when viewed from the Z direction is cut off (chamfered) so that it has a chamfered portion 20p. Here, all of the multiple (four) corners 20r are chamfered. The chamfered portion 20p may be a C-surface or an R-surface. In this embodiment, the chamfered portion 20p is an R-surface.

Next, as shown in FIG. 6, the sealing material 21 and the spacer 22 adjacent in the Z direction are welded together to form a sealing body 20 from the resin laminate 20A for sealing the internal space S formed between the electrodes (step S106, third step). More specifically, in step S106, the ends of the multiple sealing materials 21 opposite the internal space S are welded to the ends of the multiple spacers 22 opposite the internal space S to form the welded end portions 23. This forms the sealing body 20 from the resin laminate 20A. A battery body 1A is also formed that includes the electrode laminate 10 and the sealing body 20.

This sealing body 20 has a chamfered portion 20p at the corner 20r when viewed from the Z direction because the resin laminate 20A is chamfered in step S105. Therefore, in steps S105 and S106, the sealing body 20 is formed so that the corner 20r of the sealing body 20 has a chamfered portion 20p when viewed from the Z direction. In particular, in this embodiment, after the corners of the multiple sealing materials 21 and the multiple spacers 22 stacked in the Z direction (i.e., the corners 20r of the resin laminate 20A) are chamfered in step S105, the sealing materials 21 and the spacers 22 are welded in step S106, and as a result, the sealing body 20 is formed so that the corner 20r has a chamfered portion 20p. Therefore, the battery body 1A has a chamfered portion 20p at the corner 20r of the sealing body 20 when viewed from the Z direction.

In the next step, as shown in FIG. 7, the battery body 1A including the electrode stack 10 and the sealing body 20 is housed in a container 30 made of a laminate film 30L (step S107, fourth step). More specifically, in step S107, the battery body 1A is housed in the recess 31c of the first member 31 of the container 30, and the recess 31c is sealed by the second member 32.

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

The size of the chamfered portion 20p of the corner 20r of the sealing body 20 is equal to or larger than the size of the chamfered shape of the corner 30r of the container 30 (they may be the same). When the chamfered portion 20p of the corner 20r and the chamfered shape of the corner 30r are R-shaped, the chamfered portion 20p of the corner 20r is larger than the chamfered shape of the corner 30r, for example, meaning that the radius of curvature of the chamfered portion 20p of the corner 20r is equal to or larger than the radius of curvature of the chamfered shape of the corner 30r. When the chamfered portion 20p of the corner 20r and the chamfered shape of the corner 30r are C-shaped, the chamfered portion 20p of the corner 20r is larger than the chamfered shape of the corner 30r, for example, meaning that the length of one side (of the C-shaped surface) of the chamfered portion 20p of the corner 20r is equal to or larger than the length of one side of the chamfered shape of the corner 30r.

Then, the container 30 is evacuated and depressurized to bring the container 30 into close contact with the battery body 1A (step S108, fifth step). At this time, the corner 20r of the sealing body 20 having the chamfered portion 20p in the battery body 1A comes into close contact with the corner 30r of the container 30. This results in the energy storage module 1 being obtained as shown in FIG. 1.

As described above, in the method for manufacturing a storage module according to this embodiment, first, a plurality of electrode units A1, A2, and A3 each including an electrode and a sealing material 21 welded to the electrode are stacked with a spacer 22 interposed between the sealing materials 21. This results in an electrode laminate 10 including a plurality of electrodes, and a resin laminate 20A including a plurality of sealing materials 21 and a plurality of spacers 22. Next, the sealing material 21 and the spacer 22 adjacent to each other in the stacking direction (Z direction, first direction) are welded together to form a sealing body 20 from the resin laminate 20A, which has the function of sealing the internal space S formed between the electrodes. This results in a battery body 1A including the electrode laminate 10 and the sealing body 20 surrounding the electrode laminate 10. Then, the battery body 1A is housed in a container 30 formed of a laminate film 30L to obtain a storage module 1.

Here, in the energy storage module manufacturing method according to this embodiment, when the sealing body 20 is formed, the corner 20r of the sealing body 20 has a chamfered portion 20p when viewed from the Z direction. Therefore, damage to the metal layer 33 of the laminate film 30L when the corner 20r of the sealing body 20 comes into contact with the laminate film 30L is suppressed, and the reliability of the energy storage module 1 is improved.

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

In the method for manufacturing the storage module according to the present embodiment, in steps S105 and S106, the corners of the sealant 21 and the spacer 22 are chamfered and then the sealant 21 and the spacer 22 are welded together to form the sealing body 20 so that the corner 20r has a chamfered portion 20p. In this manner, in the present embodiment, before the sealing body 20 is formed by welding the sealant 21 and the spacer 22 together, the sealant 21 and the spacer 22 are chamfered, and then the chamfered corner of the sealant 21 and the chamfered corner of the spacer 22 are welded together. This allows the width of the welded portion at the corner 20r of the sealing body 20 to be sufficiently secured, improving the degree of freedom in chamfering the corner 20r. 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, the sealing property of the sealing body 20 is sufficiently secured.

In the energy storage module manufacturing method according to this embodiment, the container 30 includes a first member 31 in which a recess 31c is formed, 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 deep enough to house the battery body 1A is formed in one of the members constituting the container 30 (the first member 31).

In this way, when a deeper recess 31c is formed in the laminate film 30L compared to when recesses are provided in both components constituting the container 30, for example, in order to prevent damage to the laminate film 30L during manufacturing, the edge of the embossing press die may be largely chamfered, and a chamfered shape may be formed at the corner 30r of the recess 31c. Therefore, in order to prevent the right-angle corner of the contents contained in the recess 31c from contacting the chamfered corner 30r, it is more effective to provide a chamfered portion 20p at the corner 20r of the sealing body 20 as described above, and to prevent damage to the metal layer 33 of the laminate film 30L.

The method for manufacturing the energy storage module according to this embodiment also includes step S108, which reduces the pressure inside the container 30 after step S107. When the battery body 1A is housed in the container 30, the corner 30r that faces the corner 20r of the sealing body 20 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 equal to or larger than 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 the gap between the battery body 1A and the container 30 can be reduced in most areas other than the opposing 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 (for example, the side portion connecting the adjacent corners of the battery body 1A and the container 30 facing the side portion) other than the opposing portion where the corner 20r of the battery body 1A and the corner 30r of the container 30 face each other. As a result, when the pressure inside the container 30 is reduced, deformation of the laminate film 30L, such as wrinkles occurring in the laminate film 30L, is less likely to occur. In addition, 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.

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

In this way, in the storage module 1 according to this embodiment, the corner 20r of the sealing body 20 has a chamfered portion 20p. Therefore, when the corner 20r of the sealing body 20 comes into contact with the laminate film 30L, damage to the metal layer 33 of the laminate film 30L is suppressed, and the reliability of the storage module 1 is improved. In addition, in the storage module 1, when suppressing damage to the metal layer 33 of the laminate film 30L and improving the reliability of the storage module 1, the sealing body 20 that is formed integrally with the electrode stack 10 and has the function of sealing the electrode stack 10 is used. Therefore, in order to suppress damage to the container made of the laminate film, it is not necessary to accommodate a spacer that is configured as a separate member from the battery body and has a certain size in the container together with the battery body. As a result, in this embodiment, the proportion of the battery body 1A in the volume of the container 30 can be increased, and a decrease in the volumetric energy density of the storage module is suppressed.

The above embodiment describes one aspect of the present invention. Therefore, the present invention is not limited to the above embodiment and can be modified as desired.

For example, in the above embodiment, the corners of the sealant 21 and the spacer 22 are chamfered in step S105, and then the sealant 21 and the spacer 22 are welded together in step S106 to form the sealing body 20 so that the corner 20r has a chamfered portion 20p. However, the order of chamfering and welding may be reversed.

In this case, as shown in FIG. 8, in step S106, the sealing material 21 and the spacer 22 adjacent in the Z direction are welded together to form a sealing body 20 from the resin laminate 20A to seal the internal space S formed between the electrodes. Then, in step S105, the corners 20r of the sealing body 20 are chamfered to form the chamfered portions 20p. In this case, the chamfering of the corners 20r is performed after the sealing body 20 is formed, so that the dimensional accuracy of the chamfered portions 20p is more reliably ensured. Note that the corners of the sealing body 20 when viewed from a direction intersecting the Z direction (stacking direction), i.e., the corners of the sealing body 20 in the stacking direction, may be chamfered.

In the above embodiment, the container 30 is configured from 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 configuration). However, the container 30 may also be configured such that both the first member 31 and the second member 32 are formed into a bottomed box-shaped configuration having a recess (i.e., a double-sided embossed configuration). Figure 9 is a schematic cross-sectional view showing a storage module according to a modified example.

In the modified example shown in FIG. 9, the second member 32 includes a side wall portion 32k, a flange portion 32p, and a bottom wall portion 32f that are integrally formed. The side wall portion 32k is a rectangular tubular 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, the side wall portion 32k and the bottom wall portion 32f form a rectangular parallelepiped recess 32c. The flange portion 32p is a rectangular frame-shaped portion that is connected to the end of the side wall portion 32k opposite the bottom wall portion 32f and extends away from the recess 32c (toward the outside).

In the bottom wall portion 32f, at least in the range overlapping with the active material layers (positive electrode active material layer 16 and negative electrode active material layer 17) as viewed from the Z direction, the first resin layer 34 and the second resin layer 35 are removed, and the metal layer 33 is exposed. In the modified example of FIG. 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 established. As an example, such a second member 32 can be formed by pressing a mold against the base material of the flat laminate film 30L to form a recess 32c (for example, by embossing or drawing).

The flange portion 32p is formed in the same shape as the flange portion 31b of the first member 31, and is overlapped on the flange portion 31b. The first member 31 and the second member 32 are integrated by joining (for example, by welding) the overlapping flange portion 31b and the flange portion 32p. As a result, the continuous recesses 31c, 32c form a space in which the battery body 1A is accommodated, and the space is sealed. At this time, the sealing portion (flange portions 31b, 32p) of the container 30 is positioned halfway (for example, near the center) in the Z direction of the energy storage module 1. The pressure inside the container 30 may also be reduced during sealing.

9, a portion of the battery body 1A in the Z direction is accommodated in the recess 32c of the second member 32, and the remaining portion of the battery body 1A in the Z direction is accommodated in the recess 31c of the first member 31. Here, the recess 31c of the first member 31 and the recess 32c of the second member 32 in the modified example of FIG. 9 are each formed with a recess depth shallower than the recess depth of the recess 31c of the first member 31 in the embodiment of FIG. 1. According to the modified example as described above, the recesses 31c and 32c for accommodating the battery body 1A are shallower, which makes it easier to manufacture the container 30 by, for example, embossing, and makes it possible to thin the metal layer 33 of the laminate film 30L that serves as the base material.

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 a plurality of (four here) 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. Between adjacent energy storage modules 1, the conductive member 40 described above is interposed as an example. 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.

In this way, in the energy storage device 100, the multiple storage modules 1 stacked in the Z direction are electrically connected in series. The current collectors 15 of the electrodes of the outermost layers of the energy storage modules 1 located at both ends of the energy storage device 100 in the Z direction are each 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 member 110. Note that all of the multiple (three in this case) conductive members 40 may have a cooling flow path formed therein and have 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 a cooling flow path.

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 to expose the metal layer 33 in the areas overlapping the active material layers of the first member 31 and the second member 32, and an electrical connection was formed between the conductive member 40 and the battery body 1A inside the container 30 via the metal layer 33 in contact with the current collector 15.

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. In addition, 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, such an exposed portion of the metal layer 33 may not be formed.

Furthermore, evacuation and depressurization of the container 30 in step S108 in the above embodiment is not essential.

The following additional information is provided regarding the above embodiment.

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

[Appendix 2] In the third step, the corners of the sealing material and the spacer are chamfered, and then the sealing material and the spacer are welded together to form the sealing body so that the first corner has a chamfered portion. This is the method for manufacturing the energy storage module described in Appendix 1.

[Appendix 3] The method for manufacturing an energy storage module described in Appendix 1, in which in the third step, the sealing material and the spacer are welded together to form the sealing body, and then a chamfer is formed on the first corner.

[Appendix 4] The method for manufacturing an energy storage module described in any one of appendices 1 to 3, in which 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.

[Appendix 5] The method for manufacturing an energy storage module according to any one of appendices 1 to 4, further comprising a fifth step of reducing the pressure inside the container after the fourth step, wherein a second corner portion that faces the corner portion of the sealing body when the battery body is housed in the container has a chamfered shape, the chamfered shape of the second corner portion corresponds to the shape of the chamfered portion of the first corner portion, and the size of the chamfered portion of the first corner portion is equal to or larger than the size of the chamfered shape of the second corner portion.

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...sealing body, 20A...resin laminate (second laminate), 20r...corner (first corner), 20p...chamfered portion, 21...sealing material, 22...spacer, 23...welded end portion, 30...container, 30L...laminate film, 30r...corner (second corner), 31...first member, 31c...recess, 32...second member, 33...metal layer.

Claims (6)

A first step of preparing a plurality of electrode units each including an electrode including a current collector and a seal material provided on a peripheral portion of the current collector;
a second step of stacking the electrode units in a first direction with frame-shaped spacers interposed between the sealing materials after the first step to form a first stack including the electrodes, and a second stack including the sealing materials and the spacers and provided so as to surround the first stack;
a third step of forming a sealing body from the second laminate by welding the sealing material and the spacer adjacent to each other in the first direction after the second step, the sealing body being configured to seal an internal space formed between the electrodes;
a fourth step of housing a battery body including the first laminate and the sealed body in a container formed of a laminate film including a metal layer after the third step;
Equipped with
In the third step, the plug is formed so that a first corner portion, which is a corner portion of the plug when viewed from the first direction, has a chamfered portion.
A method for manufacturing an energy storage module. In the third step, the corners of the sealing material and the spacer are chamfered, and then the sealing material and the spacer are welded to each other to form the sealing body so as to have a chamfered portion at the first corner.
The method for manufacturing an electricity storage module according to claim 1 . In the third step, the sealing material and the spacer are welded to form the sealing body, and then a chamfer is formed on the first corner.
The method for manufacturing an electricity storage module according to claim 1 . the container includes a first member having a recess formed therein and a second member sealing the recess;
In the fourth step, the battery body is housed in the recess and the recess is sealed with the second member.
The method for manufacturing an electricity storage module according to claim 1 . A fifth step of reducing the pressure inside the container after the fourth step is provided,
a second corner portion of the container that faces the corner portion of the sealing body when the battery body is housed therein has a chamfered shape,
a chamfered shape of the second corner portion corresponds to a chamfered shape of the first corner portion,
The size of the chamfered portion of the first corner portion is equal to or larger than the size of the chamfered shape of the second corner portion.
The method for manufacturing an electricity storage module according to any one of claims 1 to 4. a battery body including a first stack including a current collector and including a plurality of electrodes stacked in a first direction, and a cylindrical sealing body provided to surround the first stack and for sealing an internal space formed between the electrodes;
A container that is made of a laminate film including a metal layer and that houses the battery body;
Equipped with
The sealing body is
a plurality of seal materials provided on peripheral portions of the current collectors of the plurality of electrodes;
a plurality of spacers interposed between adjacent ones of the sealing materials;
a welded end portion formed by welding ends of the plurality of sealing materials opposite to the internal space and ends of the plurality of spacers opposite to the internal space;
having
A first corner portion, which is a corner portion of the sealing body when viewed from the first direction, has a chamfered portion.
Energy storage module.

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