Electricity storage module manufacturing apparatus and electricity storage module manufacturing method

Abstract

A production device 41 is equipped with: fluid injection nozzles 43 which are pressed against areas surrounding the openings 31A of through-holes 31 in a side surface 23c of a sealed object 3 and inject a fluid F into a plurality of inner spaces S via the through-holes 31; a first restraining member 44, which restrains a first region F1 of the sealed object 3 where the plurality of through-holes 31 have been disposed; and a second restraining member 45, which has been disposed independently of the first restraining member 44 and restrains a second region F2 including the inner spaces S, along the stacking direction.

Description

[Technical Field]

[0001] The present disclosure relates to an apparatus for manufacturing an energy storage module and a method for manufacturing an energy storage module. [Background technology]

[0002] An example of a conventional energy storage module is the bipolar battery described in Patent Document 1. This conventional energy storage module has multiple bipolar electrodes, each with a positive electrode formed on one side of a current collector and a negative electrode formed on the other side. The multiple bipolar electrodes are stacked with separators that hold electrolyte layers interposed between them. A sealing resin is molded and arranged around the outer periphery of the separator.

[0003] The manufacturing process of the above-mentioned energy storage module may include a step of injecting an electrolyte solution into the internal space formed between the electrodes, or a step of injecting a gas into the internal space for airtightness testing. For example, Patent Document 2 discloses an injection device for injecting an electrolyte solution into an energy storage module. In this injection device, a plurality of supply nozzles are pressed against communication holes formed in the sealing body of the energy storage module, and the electrolyte solution is injected into the vacuum-state internal space through the communication holes. When injecting the electrolyte solution, the injection device is provided with a restraining jig that restrains the energy storage module at a constant pressure or a constant size in the stacking direction of the electrodes. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-151016 [Patent Document 2] Japanese Patent Application Publication No. 2018-106850 Summary of the Invention [Problem to be solved by the invention]

[0005] Constraining the energy storage module helps to suppress deformation of the energy storage module when a fluid such as an electrolyte is injected. However, in an energy storage module, the dimensional tolerance in the thickness direction (electrode stacking direction) may differ between the electrode stack, in which multiple electrodes are stacked, and the sealing body, which seals multiple internal spaces formed between the electrodes of the electrode stack. In this case, the dimensions of the electrode stack in the stacking direction and the dimensions of the sealing body in the stacking direction vary from energy storage module to energy storage module, which may change the constraining pressure applied to the energy storage module and make it impossible to appropriately suppress deformation of the energy storage module.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a manufacturing apparatus and a manufacturing method for a storage module that can appropriately suppress deformation when injecting fluid into each storage module that has dimensional variations due to dimensional tolerances. [Means for solving the problem]

[0007] An apparatus for manufacturing an energy storage module according to one aspect of the present disclosure is an apparatus for manufacturing an energy storage module used in manufacturing an energy storage module including: an electrode stack in which a plurality of electrodes, each including a current collector, are stacked; and a sealing body provided on the peripheral portion of each of the current collectors so as to surround the electrode stack, sealing a plurality of internal spaces located between adjacent current collectors in the stacking direction, and having a plurality of communication holes communicating with each of the plurality of internal spaces. The apparatus also includes: a fluid injection nozzle that is pressed against the periphery of the openings of the communication holes on a side of the sealing body to inject a fluid into each of the plurality of internal spaces through the communication holes; a first restraint member that restrains a first region of the sealing body in which the plurality of communication holes are provided; and a second restraint member that is provided independently of the first restraint member and restrains a second region including the internal spaces in the stacking direction.

[0008] In this energy storage module manufacturing apparatus, when a fluid is injected into the internal space through the communication holes using a fluid injection nozzle, the first region of the sealing body, which has multiple communication holes, and the second region, which includes the internal space, can be independently constrained by the first and second constraining members. Therefore, even if the dimensions of the electrode stack and the sealing body differ, it is possible to apply the necessary constraining pressure to each of the first and second regions. This makes it possible to appropriately suppress deformation of each energy storage module when fluid is injected, even for energy storage modules with dimensional variations due to dimensional tolerances.

[0009] The first confining pressure applied by the first confining member may be greater than the second confining pressure applied by the second confining member. In this case, the first region of the sealing body can be reliably protected from pressure from the fluid injection nozzle while preventing excessive confining force from being applied to the electrode stack. Therefore, damage to the electrode stack due to the confining force can be suppressed.

[0010] The sealing body may include a plurality of sealants covering the peripheries of the current collectors and spacers interposed between adjacent sealants in the stacking direction, and the first restraining member may restrain a region where the sealants and spacers overlap in the stacking direction as a first region. In this case, a first restraining pressure is applied to the region where the sealants and spacers overlap in the stacking direction in the first region. Therefore, deformation of the internal space between the current collectors constituting the electrode due to the first restraining pressure can be suppressed.

[0011] The device may further include a decompression chamber in which the energy storage module is placed, and a first restraint member and a second restraint member may be provided in the decompression chamber. In this case, by using the decompression chamber to reduce the pressure in the internal space of the energy storage module, fluid can be efficiently injected through the communication hole. Furthermore, by providing the first restraint member and the second restraint member in the decompression chamber, it is not necessary to attach and detach the restraint members to and from the energy storage module each time fluid is injected, thereby simplifying the work process.

[0012] The device may further include a decompression chamber in which the energy storage module is placed, with a first restraining member provided in the decompression chamber and a wall of the decompression chamber constituting the second restraining member. In this case, the internal space of the energy storage module is decompressed using the decompression chamber, allowing for efficient injection of fluid through the communication hole. Furthermore, by using the wall of the decompression chamber as the second restraining member, it is not necessary to detach the restraining member from the energy storage module each time fluid is injected, resulting in a simpler configuration and simplification of the work process.

[0013] The second constraining member may have a protrusion corresponding to the portion of the electrode stack exposed from the sealing body. In this case, the protrusion can more reliably ensure contact of the second constraining member with the electrode stack. Therefore, even if there is a large difference in size between the electrode stack and the sealing body, the second constraining member can appropriately apply a constraining force to the electrode stack.

[0014] A manufacturing method for an energy storage module according to one aspect of the present disclosure is a manufacturing method for an energy storage module used in manufacturing an energy storage module including an electrode stack in which a plurality of electrodes, each including a current collector, are stacked, and a sealing body provided on the peripheral portion of each of the current collectors so as to surround the electrode stack, sealing a plurality of internal spaces located respectively between adjacent current collectors in the stacking direction, and having a plurality of communication holes communicating with each of the plurality of internal spaces, the manufacturing method for an energy storage module including an injection step of pressing a fluid injection nozzle against the periphery of the opening of the communication hole on the side of the sealing body to inject a fluid into each of the plurality of internal spaces through the communication holes, and in the injection step, a first region of the sealing body having a plurality of communication holes is restrained by a first restraining member, and a second region including the internal spaces is restrained in the stacking direction by a second restraining member.

[0015] In this method for manufacturing an energy storage module, when a fluid is injected into the internal space through the communication holes using a fluid injection nozzle, a first region of the sealing body having a plurality of communication holes and a second region including the internal space are independently constrained by a first constraining member and a second constraining member. Therefore, even if the dimensions of the electrode stack and the sealing body differ, it is possible to apply the necessary constraining pressure to each of the first and second regions. This makes it possible to appropriately suppress deformation of the energy storage module when fluid is injected, even for energy storage modules with dimensional variations due to dimensional tolerances. [Effects of the Invention]

[0016] According to the present disclosure, deformation that occurs when fluid is injected into each of the energy storage modules having dimensional variations due to dimensional tolerances can be appropriately suppressed. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an embodiment of an electricity storage module. [Figure 2] FIG. 2 is a schematic cross-sectional view showing the configuration of the periphery of a communication hole in a sealing body. [Figure 3] FIG. 1(a) is a schematic side view showing the positional relationship between the cells and the communication holes, and FIG. 1(b) is a schematic side view showing the positional relationship between the frame and the communication holes. [Figure 4] 1 is a schematic partial cross-sectional view showing an apparatus for manufacturing an electricity storage module according to one aspect of the present disclosure. [Figure 5] 10 is a schematic cross-sectional view showing the state of the periphery of a communication hole in a filling step. FIG. [Figure 6] 10(a) and 10(b) are schematic side views showing the relationship between the dimensions of the electrode stack in the stacking direction and the dimensions of the sealing body in the stacking direction between the workpieces. [Figure 7] FIG. 2 is a schematic plan view showing a first region restrained by a first restraining member and a second region restrained by a second restraining member. [Figure 8]3 is a schematic cross-sectional view showing a first region restrained by a first restraining member and a second region restrained by a second restraining member. FIG. [Figure 9] 10(a) and 10(b) are schematic partial cross-sectional views showing modified examples of the manufacturing apparatus for the electricity storage module. [Figure 10] FIG. 10 is a schematic plan view showing a first modified example of the first region and the second region. [Figure 11] FIG. 11 is a schematic plan view showing a second modified example of the first region and the second region. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, preferred embodiments of an energy storage module manufacturing apparatus and an energy storage module manufacturing method according to one aspect of the present disclosure will be described in detail with reference to the drawings. For convenience of explanation, each drawing shows an orthogonal coordinate system defined by a coordinate axis indicating a first direction D1, a coordinate axis indicating a second direction D2, and a coordinate axis indicating a third direction D3.

[0019] First, the configuration of an energy storage module to which an energy storage module manufacturing apparatus and an energy storage module manufacturing method according to one aspect of the present disclosure are applied will be described. FIG. 1 is a schematic cross-sectional view showing one embodiment of an energy storage module. As shown in FIG. 1, the energy storage module 1 is a module used in batteries for various vehicles such as forklifts, hybrid vehicles, and electric vehicles. The energy storage module 1 is a secondary battery such as a nickel-metal hydride secondary battery or a lithium-ion secondary battery. The energy storage module 1 may be an electric double layer capacitor or an all-solid-state battery. Here, a case in which the energy storage module 1 is a lithium-ion secondary battery will be illustrated as an example.

[0020] The energy storage module 1 includes an electrode stack 2 and a sealing body 3. The electrode stack 2 includes a plurality of electrodes stacked along a first direction D1. The first direction D1 is the stacking direction of the electrodes in the electrode stack 2, and corresponds to the thickness direction of the energy storage module 1. The second direction D2 and the third direction D3 are in-plane directions of a current collector 15, which will be described later. The second direction D2 corresponds to the depth direction of the energy storage module 1, and the third direction D3 corresponds to the width direction of the energy storage module 1.

[0021] The multiple electrodes include multiple bipolar electrodes 11, a positive terminal electrode 12, and a negative terminal electrode 13. The electrode stack 2 is formed by stacking multiple bipolar electrodes 11 between a positive terminal electrode 12 and a negative terminal electrode 13. A separator 14 is disposed between adjacent electrodes in the stacking direction. The bipolar electrode 11 includes a current collector 15, a positive electrode active material layer 16, and a negative electrode active material layer 17. The current collector 15 has, for example, a rectangular sheet shape. The current collector 15 includes a first surface 15a, which is one surface, and a second surface 15b, which is the other surface opposite the first surface 15a. That is, the current collector 15 has the first surface 15a and the second surface 15b facing opposite to each other in the first direction D1. The positive electrode active material layer 16 is provided on the first surface 15a of the current collector 15. The negative electrode active material layer 17 is provided on the second surface 15b of the current collector 15. The first surface 15a of the current collector 15 faces one side of the first direction D1, and the second surface 15b of the current collector 15 faces the other side of the first direction D1.

[0022] In the electrode stack 2, the 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 adjacent to the one bipolar electrode 11. The positive electrode active material layer 16 and the negative electrode active material layer 17 have a rectangular shape when viewed from the first direction D1. In this embodiment, the negative electrode active material layer 17 is slightly larger than the positive electrode active material layer 16 when viewed from the first direction D1. That is, in a plan view when viewed from the first direction D1, the entire formation region of the positive electrode active material layer 16 is located within the formation region of the negative electrode active material layer 17.

[0023] The positive terminal electrode 12 has a current collector 15 and a positive electrode active material layer 16 provided on a first surface 15a of the current collector 15. No active material layer is provided on a second surface 15b of the current collector 15 in the positive terminal electrode 12. The positive terminal electrode 12 is stacked on the bipolar electrode 11 at one end of the electrode laminate 2 in the first direction D1. The positive electrode active material layer 16 of the positive terminal electrode 12 and the negative electrode active material layer 17 of the bipolar electrode 11 adjacent to the positive terminal electrode 12 face each other. The second surface 15b of the current collector 15 in the positive terminal electrode 12 has an exposed portion R1 exposed from the sealing body 3 as one stacking end of the electrode laminate 2. In other words, the second surface 15b of the current collector 15 in the positive terminal electrode 12 serves as the positive terminal surface of the energy storage module 1.

[0024] The negative electrode terminal electrode 13 has a current collector 15 and a negative electrode active material layer 17 provided on a second surface 15b of the current collector 15. No active material layer is provided on a first surface 15a of the current collector 15 in the negative electrode terminal electrode 13. The negative electrode terminal electrode 13 is stacked on the bipolar electrode 11 at the other end of the electrode laminate 2 in the first direction D1. The negative electrode active material layer 17 of the negative electrode terminal electrode 13 and the positive electrode active material layer 16 of the bipolar electrode 11 adjacent to the negative electrode terminal electrode 13 face each other. The first surface 15a of the current collector 15 in the negative electrode terminal electrode 13 has an exposed portion R2 exposed from the sealing body 3 as the other stacking end of the electrode laminate 2. In other words, the first surface 15a of the current collector 15 in the negative electrode terminal electrode 13 serves as the negative electrode terminal surface of the energy storage module 1.

[0025] Conductive members 18 are disposed on an exposed portion R1 of the first surface 15a of the current collector 15 of the positive terminal electrode 12, which is exposed from the sealing body 3, and on an exposed portion R2 of the second surface 15b of the current collector 15 of the negative terminal electrode 13, which is exposed from the sealing body 3. The conductive members 18 disposed on the exposed portions R1 and R2 are electrically connected to the electrode stack 2 via the exposed portions R1 and R2, respectively, and function as terminals for extracting current from the energy storage module 1. The conductive members 18 also function as restraining members that apply a predetermined restraining load to the electrode stack 2. A cooling flow path may be formed in the conductive member 18. By circulating a cooling medium through the cooling flow path, the electrode stack 2 can be efficiently cooled.

[0026] The separators 14 are respectively disposed between adjacent bipolar electrodes 11 in the first direction D1, between the positive terminal electrode 12 and the bipolar electrode 11, and between the negative terminal electrode 13 and the bipolar electrode 11. The separators 14 are disposed between the positive electrode active material layer 16 and the negative electrode active material layer 17 between the electrodes. By isolating the positive electrode active material layer 16 and the negative electrode active material layer 17, the separators 14 have the role of preventing short circuits due to contact between adjacent electrodes while allowing charge carriers such as lithium ions to pass through.

[0027] The separator 14 is made of, for example, a porous sheet containing a polymer that absorbs and retains electrolyte, or a nonwoven fabric. Examples of materials for the separator 14 include polypropylene, polyethylene, polyolefin, and polyester. The separator 14 may have either a single-layer structure or a multi-layer structure. If the separator 14 has a multi-layer structure, it may have, for example, a ceramic layer as an adhesive layer or a heat-resistant layer.

[0028] The separator 14 may be impregnated with an electrolyte. Examples of the electrolyte impregnated in the separator 14 include a liquid electrolyte (electrolytic solution) containing a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent. Examples of the electrolyte salt contained in the electrolytic solution include lithium salts such as LiClO4, LiAsF6, LiPF6, LiBF4, LiCF3SO3, LiN(FSO2)2, and LiN(CF3SO2)2. Examples of the non-aqueous solvent include cyclic carbonates, cyclic esters, chain carbonates, chain esters, and ethers. Two or more of these solvents may be used in combination.

[0029] The current collector 15 is a chemically inactive electrical conductor for continuously supplying current to the positive electrode active material layer 16 and the negative electrode active material layer 17 during discharge or charge of the lithium-ion secondary battery. Examples of materials for the current collector 15 include metal materials, conductive resin materials, and conductive inorganic materials. Examples of conductive resin materials include conductive polymer materials and resins obtained by adding a conductive filler to a non-conductive polymer material as needed. The current collector 15 may have multiple layers. In this case, each layer of the current collector 15 may contain the above-mentioned metal materials, conductive resin materials, etc.

[0030] A coating layer may be formed on the surface of the current collector 15. The coating layer is formed by, for example, plating, spray coating, or other methods. The current collector 15 may have various shapes, such as a plate, foil (e.g., metal foil), film, or mesh. Examples of metal foils include aluminum foil, copper foil, nickel foil, titanium foil, and stainless steel foil. The current collector 15 may be an alloy foil of any of the above metals, or a foil formed by integrating multiple metal foils. When the current collector 15 is in the form of a foil, the thickness of the current collector 15 may be, for example, about 1 μm to 100 μm.

[0031] The positive electrode active material layer 16 is a layer containing 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, and polyanionic compounds. 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), which is a composite oxide.

[0032] The negative electrode active material layer 17 is a layer containing 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, and 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 alloying with lithium, or a compound thereof. Examples of carbon include natural graphite, artificial graphite, hard carbon (non-graphitizable carbon), and soft carbon (easily graphitizable carbon). Examples of artificial graphite include highly oriented graphite and mesocarbon microbeads. Examples of elements capable of alloying with lithium include silicon and tin. In this embodiment, the negative electrode active material layer 17 contains graphite, which is a carbon-based material.

[0033] Each of the positive electrode active material layer 16 and the negative electrode active material layer 17 may further contain, as necessary, a conductive additive for improving electrical conductivity, a binder, an electrolyte (such as a polymer matrix, an ion-conductive polymer, or an electrolyte solution), an electrolyte supporting salt (lithium salt) for improving ionic conductivity, etc. The conductive additive is added to improve the conductivity of each electrode (bipolar electrode 11, positive terminal electrode 12, and negative terminal electrode 13). Examples of the conductive additive include acetylene black, carbon black, and graphite.

[0034] 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 and methacrylic acid; styrene-butadiene rubber (SBR); carboxymethyl cellulose; alginates such as sodium alginate and ammonium alginate; water-soluble cellulose ester crosslinks; and starch-acrylic acid graft polymers. These binders can be used alone or in combination. Examples of solvents that can be used include water and N-methyl-2-pyrrolidone (NMP).

[0035] The sealing body 3 is formed in a frame shape on the periphery of the electrode stack 2 so as to surround the electrode stack 2. The sealing body 3 is joined to each of the first surface 15a and the second surface 15b of the current collector 15 at the periphery 15c of each current collector 15. The sealing body 3 forms an internal space S between each of the current collectors 15 adjacent to each other in the first direction D1 and seals each of these internal spaces S. The above-mentioned electrolyte (electrolytic solution) is accommodated in each of the internal spaces S. The sealing body 3, together with the current collectors 15 adjacent to each other in the first direction D1, defines the internal space S that accommodates the electrolytic solution and prevents leakage of the electrolytic solution from the internal space S to the outside.

[0036] The sealing body 3 prevents moisture and the like from penetrating into the internal space S from the outside of the electrode stack 2. In this embodiment, the peripheral portion of the separator 14 is joined to the sealing body 3 while being embedded in the sealing body 3. The sealing body 3 is formed of, for example, an insulating resin material. Examples of the resin material include polypropylene, polyethylene, polystyrene, ABS resin, acid-modified polypropylene, acid-modified polyethylene, and acrylonitrile-styrene resin.

[0037] The main body 20 of the sealing body 3 includes a plurality of sealants 21, a plurality of spacers 22, and a welded end portion 23. A sealant 21 is provided for each current collector 15. The sealant 21 is frame-shaped and provided on the peripheral edge 15c of the current collector 15. The sealant 21 covers the first surface 15a, the second surface 15b, and the end faces of the peripheral edge 15c of the current collector 15. The sealant 21 is welded to at least one of the first surface 15a and the second surface 15b of the current collector 15.

[0038] The spacers 22 are disposed between the sealing materials 21 adjacent to each other in the first direction D1. The spacers 22 maintain the space between the adjacent sealing materials 21, i.e., the space between the adjacent current collectors 15. The spacers 22 are frame-shaped and disposed on the peripheral edge portions 15c of the current collectors 15. The peripheral edge portions of the separators 14 are sandwiched between the sealing materials 21 and the spacers 22. The peripheral edge portions of the separators 14 are welded to at least one of the sealing materials 21 and the spacers 22.

[0039] In this embodiment, the edge 22a of each spacer 22 on the internal space S side is located outside (on the opposite side to the internal space S) of the edge 21a of each sealant 21 on the internal space S side. When viewed from the first direction D1, there is a gap between adjacent sealants 21 in the region between the edges 21a and 22a. On the other hand, in the region outside the edges 22a, the spacers 22 are interposed between the adjacent sealants 21, so that the sealants 21 and the spacers 22 overlap each other.

[0040] The welded end 23 has a frame shape surrounding the electrode stack 2 when viewed from the first direction D1. The welded end 23 is formed by integrating, through welding, an edge portion of each sealant 21 opposite the internal space S with an edge portion of each spacer 22 opposite the internal space S. In this embodiment, the welded end 23 is formed by welding together a portion of each sealant 21 located outside the outer periphery of the current collector 15 and a portion of each spacer 22 located outside the outer periphery of the current collector 15. A side surface 23s of the welded end 23 located opposite the internal space S extends along the first direction D1 and constitutes a side surface of the main body 20, i.e., a side surface of the sealing body 3.

[0041] The sealing body 3 has a buildup portion 25 and a frame portion 26. The buildup portion 25 is provided on the outer surface in the first direction D1 of a seal material 21 provided on the current collector 15 of the positive terminal electrode 12 and the negative terminal electrode 13. The buildup portion 25 is arranged in the same region as the seal material 21 when viewed from the first direction D1, and is adhered to the seal material 21. An edge portion of the buildup portion 25 on the opposite side to the internal space S is welded to an edge portion of each seal material 21 on the opposite side to the internal space S, and forms a part of the welded end portion 23.

[0042] The frame portion 26 is joined to a side surface of the sealing body 3, i.e., a side surface 23s of the welded end portion 23. The frame portion 26 extends from the buildup portion 25 on the positive terminal electrode 12 side to the buildup portion 25 on the negative terminal electrode 13 side. Here, the outer edge of the frame portion 26 in the first direction D1 coincides with the outer surface of the buildup portion 25 in the first direction D1. The frame portion 26 may be joined to the buildup portion 25 or may be formed integrally with the buildup portion 25. The frame portion 26 and the buildup portion 25 may be formed integrally by, for example, injection molding. The frame portion 26 is sealed by a sealing film 30. This seals the multiple cells of the energy storage module 1. The sealing film 30 is, for example, a resin film or a laminate film.

[0043] The configuration of the sealing body 3 will be described in further detail below.

[0044] Fig. 2 is a schematic cross-sectional view showing the configuration of the periphery of a communication hole in a sealing body. Fig. 3(a) is a schematic side view showing the positional relationship between the cell and the communication hole, and Fig. 3(b) is a schematic side view showing the positional relationship between the frame body and the communication hole. For ease of explanation, Fig. 3(a) omits illustration of the frame portion 26 and the sealing film 30, and Fig. 3(b) omits illustration of the sealing film 30.

[0045] As shown in FIGS. 2, 3(a), and 3(b), a plurality of communication holes 31 that communicate with each of the plurality of internal spaces S are formed in the main body 20 of the sealing body 3. Here, the plurality of communication holes 31 are provided in a wall portion 3A (see FIG. 7) of the frame-shaped sealing body 3 that is located on one side in the second direction D2. The communication holes 31 are formed, for example, by cutting out a portion of the spacer 22, penetrating the spacer 22 and the welded end portion 23. One opening 31A of the communication holes 31 faces the side surface 23s of the welded end portion 23, and the other opening 31B faces the internal space S.

[0046] In the energy storage module 1, a cell C including one internal space S is formed by a pair of current collectors 15 adjacent to each other in the first direction D1. Here, one communication hole 31 is provided for one cell C. As shown in FIG. 3(a), when viewed from a second direction D2 intersecting (orthogonal to) the side surface 23s, the positions of the communication holes 31 in the first direction D1 differ for each cell C. Furthermore, the positions of the communication holes 31 in the third direction D3 of the cells C adjacent to each other in the first direction D1 differ from each other. In the example of FIGS. 3(a) and 3(b), the positions of the communication holes 31 adjacent to each other in the first direction D1 are staggered in the third direction D3.

[0047] 3(a) and 3(b), a plurality of communication holes 31 at the same position in the third direction D3 are provided corresponding to every other cell C. When the sealing body 3 is viewed from the second direction D2, a group of openings 31A arranged along the first direction D1 and another group of openings 31A arranged along the first direction D1 are lined up at different positions in the third direction D3 on the side surface 23s.

[0048] As shown in FIG. 3(b), the frame portion 26 is provided to protrude from the side surface 23s so as to surround each opening 31A of the plurality of communication holes 31. In the example of FIG. 3(b), a plurality of frame portions 26 are provided for the plurality of communication holes 31. The plurality of frame portions 26 are arranged spaced apart from each other in the third direction D3. Here, one frame portion 26 surrounds each of a group of openings 31A arranged along the first direction D1, and another frame portion 26 surrounds each of another group of openings 31A arranged along the first direction D1.

[0049] The multiple frame portions 26 may be configured to form multiple enclosed regions having the same length in the first direction D1, or may be configured to form multiple enclosed regions 33 having different lengths in the first direction D1. In the example of FIG. 3(b), each of the frame portions 26 forms three enclosed regions 33. One of the three enclosed regions 33 (enclosed region 33A) has a longer length in the first direction D1 than the other two enclosed regions 33.

[0050] When multiple frame portions 26 are arranged side by side in the third direction D3, two of the frame portions 26 may have the arrangement patterns of the enclosed regions 33 reversed to each other in the first direction D3. In the example of FIG. 3(b), the positions of the enclosed regions 33A in the first direction D1 are different between the frame portions 26 adjacent to each other in the third direction D3. By configuring the multiple frame portions 26 in this way, it is possible to surround each of the openings 31A of the multiple communication holes 31 that are positioned at different positions in the first direction D1 with fewer types of frame portions 26.

[0051] Next, a method for manufacturing the above-mentioned power storage module 1 will be described.

[0052] The manufacturing method for this electricity storage module 1 includes an injection step of pressing a fluid injection nozzle 43 (see FIGS. 4 and 5) against the periphery of the opening 31A of the communication hole 31 and injecting a fluid F into each of the multiple internal spaces S through the communication hole 31. Specific examples of the injection step include a step of injecting an electrolyte solution into the internal space S and a step of inspecting the airtightness of the electricity storage module 1. In the step of injecting the electrolyte solution, the electrolyte solution, which is the fluid F, is injected into the internal space S of each cell C through the communication hole 31.

[0053] The step of conducting an airtightness test is carried out before the step of injecting the electrolyte. As an airtightness test, for example, an airtightness test between the cell and the outside is carried out to check the airtightness of each cell from the outside. In this case, the fluid F is a test gas. In the cell-exterior airtightness test, a test gas such as helium is injected into the internal space S of all cells C through the communication holes 31, and a detection sensor disposed outside the energy storage module 1 detects whether or not the test gas is leaking. If the detection sensor does not detect the test gas, it is determined that there is no problem with the airtightness between the cell and the outside.

[0054] Fig. 4 is a schematic partial cross-sectional view showing an apparatus for manufacturing an electricity storage module according to one aspect of the present disclosure. As shown in Fig. 4, in this embodiment, the injection step is carried out using an electricity storage module manufacturing apparatus 41. The manufacturing apparatus 41 includes a decompression chamber 42, a fluid injection nozzle 43, a first restraining member 44, and a second restraining member 45. Of the components shown in Fig. 1, the electricity storage module 1, which is the workpiece in the injection step, does not have the conductive member 18 and the sealing film 30. The conductive member 18 and the sealing film 30 are attached to the workpiece in a step following the injection step, and the electricity storage module 1 shown in Fig. 1 is obtained.

[0055] The decompression chamber 42 has a stage 46 and a chamber 47. The stage 46 has a mounting surface 46a on which the power storage module 1 is placed. The power storage module 1 is placed on the mounting surface 46a, for example, in a state where it is placed on a flat pallet 48. The chamber 47 is formed in a box shape by four side walls 49 standing on the stage 46 and a roof 50 that closes the space defined by the stage 46 and the side walls 49.

[0056] In the chamber 47, one of the four side walls 49 is configured to be openable and closable. By opening this side wall 49, the energy storage module 1 placed on the flat pallet 48 can be inserted into and removed from the chamber 47. Of the four side walls 49, a pair of side walls 49, 49 that intersect with the side wall 49 on which the fluid injection nozzle 43 is provided, may be configured to be openable and closable. In this case, the energy storage module 1 placed on the flat pallet 48 can be introduced into the chamber 47 from one side of the pair of side walls 49, 49, and can be removed from the other side of the pair of side walls 49, 49 after the injection process has been performed. This makes it possible to perform the injection process while transporting a plurality of energy storage modules 1 in one direction, thereby improving the efficiency of the injection process.

[0057] The fluid injection nozzle 43 is provided on one side wall portion 49 of the chamber 47 so as to be movable forward and backward relative to the mounting surface 46a. As shown in FIG. 5, the fluid injection nozzle 43 has a nozzle head 51 that injects the fluid F. As shown in FIG. 5, the nozzle head 51 has a head main body 52 and a packing 53, and is disposed within the chamber 47. The head main body 52 is provided with a flow path 54 through which the fluid F flows. The packing 53 is provided on the tip surface of the head main body 52. ​​The packing 53 is provided with a discharge hole 55 that communicates with the flow path 54.

[0058] When the fluid F is injected from the fluid injection nozzle 43 into the internal space S, the fluid injection nozzle 43 advances toward the mounting surface 46a, and the packing 53 of the nozzle head 51 is pressed against the frame 26, thereby sealing the enclosed area 33 of the frame 26 from the outside. In this state, the fluid F is discharged from the discharge hole 55 of the nozzle head 51, and the fluid F is injected into the internal space S of each cell C in the energy storage module 1 via the communication hole 31.

[0059] When injecting the fluid F, before pressing the nozzle head 51 against the frame 26, the chamber 47 is evacuated with the electricity storage module 1 placed thereon, thereby reducing the pressure in the internal space S of each cell C in the electricity storage module 1. When injecting the electrolyte solution, by reducing the pressure in the internal space S of the electricity storage module 1 using the decompression chamber 42, the electrolyte solution can be efficiently injected through the communication holes 31.

[0060] If the internal space S of the electricity storage module 1 is depressurized under atmospheric pressure, the electricity storage module 1 may be crushed by the atmospheric pressure, and the current collectors 15 that constitute each internal space S may be deformed, causing the entrance to the internal space S (the portion connected to the communication hole 31) to become blocked. As a result, it is thought that the efficiency of injection of a fluid F such as an electrolyte solution or a test gas may not be improved. In response to this, by placing the electricity storage module 1 in a decompression chamber 42 and decompressing the internal space S of the electricity storage module 1 as well as the outside of the electricity storage module 1, the pressure difference between the inside and outside of each cell C is eliminated, and the efficiency of injection of a fluid F such as an electrolyte solution or a test gas can be sufficiently improved.

[0061] The same applies when injecting the test gas; by reducing the pressure in the internal space S of the energy storage module 1 using the decompression chamber 42, the test gas can be efficiently injected through the communication hole 31. Furthermore, by placing the energy storage module 1 inside the decompression chamber 42, the influence of the test gas contained in the atmosphere is suppressed, and the accuracy of the airtightness test can be improved.

[0062] The first restraining member 44 and the second restraining member 45 are members that restrain the electricity storage module 1 at a constant pressure or at a constant size in order to protect the electrode stack 2 and the sealing body 3 from the load that occurs when injecting the fluid F. Examples of the load that occurs when injecting the fluid F include the pressing force that acts on the main body 20 of the sealing body 3 when the fluid injection nozzle 43 is pressed against the periphery of the opening 31A of the communication hole 31, the expansion force of the internal space S due to the injection of the fluid F, and the expansion force of the internal space S due to the pressure difference between the inside and outside of the cell C when placed in the decompression chamber 42.

[0063] It is desirable to apply an appropriate confining pressure to both the portion of the sealing body 3 against which the fluid injection nozzle 43 is pressed and to the electrode stack 2 in which the internal space S is located. However, in an energy storage module 1, the dimensional tolerance in the thickness direction (first direction D1 / electrode stacking direction) may differ between the electrode stack 2 in which multiple electrodes are stacked and the sealing body 3 that seals the internal space S formed between the electrodes of the electrode stack 2. Because the dimensional tolerance in the stacking direction during manufacturing differs between the electrode stack 2 and the sealing body 3, the dimensions in the stacking direction may differ between the electrode stack 2 and the sealing body 3 for each energy storage module 1 (work).

[0064] For example, the dimensional tolerance in the stacking direction of an electrode stack 2 in which multiple electrodes are stacked may be larger than the dimensional tolerance in the stacking direction of the sealing body 3. In some workpieces, as shown in FIG. 6(a), the dimension in the stacking direction of the electrode stack 2 may be smaller than the dimension in the stacking direction of the sealing body 3. In this workpiece, the end faces in the stacking direction of the electrode stack 2 (here, the first surface 15a of the current collector 15 in the positive terminal electrode 12 and the second surface 15b of the current collector 15 in the negative terminal electrode 13) are recessed relative to the end faces in the stacking direction of the sealing body 3 (here, the outer surfaces in the first direction D1 of the sealant 21 provided on the current collectors 15 of the positive terminal electrode 12 and the negative terminal electrode 13).

[0065] 6(b), in another workpiece, the dimension in the stacking direction of the electrode laminate 2 may be larger than the dimension in the stacking direction of the sealing body 3. In this workpiece, the end faces in the stacking direction of the electrode laminate 2 (here, the first surface 15a of the current collector 15 in the positive terminal electrode 12 and the second surface 15b of the current collector 15 in the negative terminal electrode 13) protrude relative to the end faces in the stacking direction of the sealing body 3 (here, the outer surfaces in the first direction D1 of the sealing materials 21 provided on the current collectors 15 of the positive terminal electrode 12 and the negative terminal electrode 13).

[0066] 6(a) and 6(b), if the electrode stack 2 and sealing body 3 of the workpiece are constrained with a uniform constraining force by a single constraining member, it is conceivable that the constraining pressure will be insufficient for either the portion of the sealing body 3 against which the fluid injection nozzle 43 is pressed, or the electrode stack 2 where the internal space S is located. In contrast, the manufacturing apparatus 41 has a first constraining member 44 and a second constraining member 45 that are provided independently of each other, so that even if the dimensions of the electrode stack 2 in the stacking direction and the dimensions of the sealing body 3 in the stacking direction vary for each energy storage module 1, it is possible to apply an appropriate constraining pressure to both the portion of the sealing body 3 against which the fluid injection nozzle 43 is pressed, and the electrode stack 2 where the internal space S is located.

[0067] As shown in FIG. 4, the first restraint member 44 includes a cylinder 61 that is extendable and retractable in a first direction D1, and a restraint plate 62 attached to the tip of the cylinder 61. In this embodiment, a pair of first restraint members 44A, 44B is employed. The first restraint member 44A is provided on the stage 46 of the decompression chamber 42 so as to be able to move back and forth in the first direction D1. The first restraint member 44B is provided on the roof 50 of the chamber 47 so as to face the first restraint member 44A and to be able to move back and forth in the first direction D1. The restraint plate 62 is made of, for example, metal or a laminate of metal and hard resin. Examples of metal include aluminum and stainless steel (SUS). Examples of hard resin include hard urethane and acrylic resin.

[0068] Constraint plate 62A and constraint plate 62B are both disposed within chamber 47. Constraint plate 62A and constraint plate 62B have, for example, the same planar shape. Cylinder 61A of first constraining member 44 and cylinder 61B of second constraining member 45 cooperate to sandwich power storage module 1, which is the workpiece, between constraint plate 62A and constraint plate 62B, and thereby constraining pressure is applied to a predetermined region of power storage module 1.

[0069] The first restraining member 44 restrains the first region F1 of the sealing body 3, in which the plurality of communication holes 31 are provided, with a first restraining pressure P1. In the present embodiment, the first restraining pressure P1 by the first restraining member 44 is applied to the first region F1 in the stacking direction (first direction D1). The first region F1 is a region where the sealing material 21 and the spacer 22 overlap in the stacking direction. In the present embodiment, as shown in FIG. 7 , when the energy storage module 1 is viewed from the stacking direction, the first region F1 is a rectangular (here, oblong) region that corresponds to the wall portion 3A of the sealing body 3 in which the plurality of communication holes 31 are provided.

[0070] 7 and 8, the first restraining member 44 restrains, as a first region F1, an area of ​​the spacer 22 of the wall portion 3A that is outward from the edge 22a of the spacer 22 on the side of the internal space S when viewed from the first direction D1. That is, the first region F1 extends in the second direction D2 across the edge 22a of the spacer 22 on the side of the internal space S and the side surface 23s of the welded end portion 23 of the wall portion 3A.

[0071] In this embodiment, as described above, the buildup portion 25 is provided on the outer surface in the first direction D1 of the sealing material 21 provided on the current collector 15 of the positive terminal electrode 12 and the negative terminal electrode 13. In the example of Fig. 7, the entire formation area of ​​the buildup portion 25 is included in the first region F1. Note that the length in the third direction D3 of the restraint plates 62A and 62B that sandwich the first region F1 may be greater than the length of the first region F1 in the third direction D3.

[0072] As shown in FIG. 4 , the second restraint member 45 has a plurality of cylinders 63 that are extendable and retractable in the first direction D1, and restraint plates 64 attached to the tips of the cylinders 63. The second restraint member 45 is provided on the roof 50 of the chamber 47 so as to be able to move back and forth in the first direction D1, facing the mounting surface 46a of the stage 46. The restraint plate 64 is arranged alongside the restraint plate 62B inside the chamber 47. When the cylinders 63 are driven, the energy storage module 1, which is the workpiece, is sandwiched between the restraint plate 64, the stage 46, and the pallet 48, thereby applying restraint pressure to a predetermined region of the energy storage module 1. The restraint plate 64 is made of, for example, a metal. Examples of metal include aluminum and stainless steel (SUS).

[0073] The second restraining member 45 restrains the second region F2 including the internal space S with a second restraining pressure P2. In the present embodiment, the second restraining pressure P2 by the second restraining member 45 is applied to the second region F2 in the first direction D1. In the present embodiment, as shown in FIG. 7 , when the energy storage module 1 is viewed from the stacking direction, the second region F2 is a rectangular (here, oblong) region corresponding to the exposed portions R1, R2 and the three wall portions 3B, 3C, and 3D of the sealing body 3 excluding the wall portion 3A.

[0074] 7 and 8, the second restraining member 45 restrains an area opposite to the first area F1 as a second area F2, with the boundary being the edge 22a of the spacer 22 of the wall portion 3A on the side of the internal space S as the boundary, when viewed from the first direction D1. That is, the second area F2 extends in the second direction D2 from the edge 22a of the spacer 22 on the side of the internal space S to the side surface 23s of the welded end portion 23 of the wall portion 3B. Note that the length of the restraining plates 64 that sandwich the second area F2 may be greater than the length of the second area F2 in the third direction D3.

[0075] In this embodiment, as shown in Fig. 4, the second restraining member 45 has a protrusion 65 that corresponds to the exposed portion R1 of the electrode stack 2 that is not exposed from the sealing body 3. The planar shape of the protrusion 65 is, for example, the same as the planar shape of the exposed portion R1. The protrusion 65 is formed, for example, by thickening a portion of the restraining plate 64 of the second restraining member 45. As a result, when the second restraining member 45 restrains the energy storage module 1, the thick protrusion 65 faces the exposed portion R1 of the electrode stack 2, and the peripheral portions that are thinner than the protrusion 65 face each of the wall portions 3B, 3C, and 3D of the sealing body 3.

[0076] In this embodiment, the first confining pressure P1 applied by the first confining member 44 is greater than the second confining pressure P2 applied by the second confining member 45. This makes it possible to apply to the first region F1 a strong confining pressure that can withstand the load caused by the pressing of the fluid injection nozzle 43. On the other hand, the second confining pressure P2 need only be a pressure that can suppress deformation of the electrode stack 2 due to expansion of the internal space S, and a confining pressure that is weaker than the first confining pressure P1 may be sufficient in some cases. By not making the second confining pressure P2 excessively large, damage to the electrode stack 2 due to confinement (such as breakage or deformation of the current collector 15) can be suppressed.

[0077] When the injection step is performed using the above-described manufacturing apparatus 41, first, the workpiece, that is, the energy storage module 1, is placed in the chamber 47 of the decompression chamber 42. Next, the cylinder 61 of the first restraining member 44 is driven relative to the energy storage module 1 in the chamber 47, thereby sandwiching the first region F1 of the energy storage module 1 between the restraining plates 62A and 62B. As a result, the first region F1 of the sealing body 3, in which the plurality of communication holes 31 are provided, is restrained in the stacking direction by the first restraining member 44 at a first restraining pressure P1.

[0078] Furthermore, by driving the cylinder 63 of the second restraining member 45 relative to the energy storage module 1 in the chamber 47, the second region F2 of the energy storage module 1 is sandwiched between the restraining plate 64, the stage 46, and the pallet 48. As a result, the second region F2 including the exposed portions R1, R2 of the electrode stack 2 is restrained by the second restraining member 45 at a second restraining pressure P2. The restraint by the first restraining member 44 and the restraint by the second restraining member 45 may be performed in either order, or may be performed simultaneously.

[0079] After the first restraining member 44 and the second restraining member 45 have been applied, the chamber 47 is evacuated. This reduces the pressure inside the chamber 47, and the internal space S of each cell C is evacuated via the multiple communication holes 31, reducing the pressure in these internal spaces S. After the pressure in each internal space S has been reduced, the fluid injection nozzle 43 is pressed against the frame 26 around the opening 31A of the communication hole 31, and the fluid F discharged from the nozzle head 51 is injected into the internal space S of each cell C via the communication hole 31. After the injection step has been performed, the conductive member 18 and the sealing film 30 are attached to the workpiece, the electricity storage module 1, to obtain the electricity storage module 1 shown in FIG. 1 .

[0080] As described above, in the manufacturing apparatus 41 and manufacturing method, when the fluid injection nozzle 43 injects the fluid F into the internal space S through the communication holes 31, the first region F1 of the sealing body 3, where the plurality of communication holes 31 are provided, and the second region F2 including the internal space S, can be constrained by the first constraining member 44 and the second constraining member 45 with independent constraining pressures. Therefore, even if the electrode stack 2 and the sealing body 3 differ in size, it is possible to apply the necessary constraining pressure to each of the first region F1 and the second region F2. This makes it possible to appropriately suppress deformation of the energy storage module 1 when injecting the fluid F for each of the energy storage modules 1 having dimensional variations due to dimensional tolerances. By applying the necessary constraining pressure to each of the first region F1 and the second region F2, the electrode stack 2 and the sealing body 3 can be appropriately protected from, for example, expansion and deformation of the electrode stack 2 due to the injection of the fluid F and damage to the sealing body 3 due to the pressure of the fluid injection nozzle 43.

[0081] In this embodiment, the first confining pressure P1 applied by the first confining member 44 is greater than the second confining pressure P2 applied by the second confining member 45. In this case, the first region F1 of the sealing body 3 can be reliably protected against the pressure of the fluid injection nozzle 43, while preventing excessive confining force from being applied to the electrode stack 2. Therefore, damage to the electrode stack 2 caused by the confining force can be suppressed.

[0082] In this embodiment, the sealing body 3 includes a plurality of sealants 21 that cover the peripheral edge portions 15c of the current collectors 15, and spacers 22 that are interposed between adjacent sealants 21 in the stacking direction. The first restraining member 44 restrains the region where the sealants 21 and spacers 22 overlap in the stacking direction as a first region F1. This applies a first restraining pressure P1 to the region in the first region F1 where the sealants 21 and spacers 22 overlap in the stacking direction. This prevents the first restraining pressure P1 from deforming the internal space S between the current collectors 15 that constitute the electrode.

[0083] In this embodiment, the manufacturing apparatus 41 further includes a decompression chamber 42 in which the energy storage module 1 is placed, and a first restraining member 44 and a second restraining member 45 are provided in the decompression chamber 42. With this configuration, the internal space S of the energy storage module 1 is decompressed using the decompression chamber 42, thereby enabling efficient injection of the fluid F through the communication hole 31. Furthermore, by providing the first restraining member 44 and the second restraining member 45 in the decompression chamber 42, it is no longer necessary to attach and detach the restraining members to and from the energy storage module 1 each time fluid F is injected, thereby simplifying the work process.

[0084] In this embodiment, the second restraining member 45 is provided with a protrusion 65 that corresponds to the exposed portion R1 of the electrode stack 2 that is not exposed from the sealing body 3. Such a protrusion 65 can more reliably ensure contact of the second restraining member 45 with the electrode stack 2. Therefore, even if there is a large difference in size between the electrode stack 2 and the sealing body 3, the second restraining member 45 can appropriately apply a restraining force to the electrode stack 2.

[0085] The present disclosure is not limited to the above-described embodiment. For example, in the above-described embodiment, the first restraining member 44 and the second restraining member 45 are respectively provided in the decompression chamber 42. However, as in a manufacturing apparatus 71 shown in Figures 9(a) and 9(b), the first restraining member 44 may be provided in the decompression chamber 42, and the wall of the decompression chamber 42 may constitute the second restraining member 45. In this manufacturing apparatus 71, a protrusion 65 corresponding to the second region F2 of the energy storage module 1 is provided on the roof portion 50 so as to face the stage 46, and the roof portion 50 having this protrusion 65 constitutes the second restraining member 45.

[0086] The "second restraining member" of the present disclosure is not limited to a member that restrains the second region F2 in the stacking direction before the injection of the fluid F, as in the above embodiment, but may also include a member that restrains the second region F2 in the stacking direction after the start of the injection of the fluid F. In the manufacturing apparatus 71, as shown in FIG. 9( a), the distance between the protrusion 65 and the stage 46 is set to be slightly larger than the dimension of the energy storage module 1 in the stacking direction before the fluid is injected. In the manufacturing apparatus 71, as shown in FIG. 9( b), in the injection step, the injection of the fluid F causes the internal space S to expand, so that the energy storage module 1, which is the workpiece, comes into contact with the protrusion 65, and the amount of expansion is regulated by the protrusion 65.

[0087] Even in this configuration, by reducing the pressure in the internal space S of the electricity storage module 1 using the decompression chamber 42, the fluid F can be efficiently injected through the communication hole 31. Furthermore, by using the wall portion (here, the roof portion 50) of the decompression chamber 42 as the second restraining member 45, it is no longer necessary to attach and detach the restraining member to the electricity storage module 1 each time fluid F is injected, and the configuration is simpler, thereby simplifying the work process.

[0088] In the above embodiment, the first confining pressure P1 by the first confining member 44 is applied to the first region F1 in the stacking direction (first direction D1). However, the first confining pressure P1 may also be applied to the first region F1 in a direction intersecting the stacking direction (e.g., third direction D3). That is, the first confining pressure P1 may be applied in any direction intersecting the extension direction of the communication hole 31 (second direction D2 in the above embodiment). Even when the first confining pressure P1 is applied in these directions, the necessary confining pressure can be applied to the first region F1. Therefore, damage to the sealing body 3 due to the pressure of the fluid injection nozzle 43 can be suppressed.

[0089] In the above embodiment, the first confining pressure P1 is greater than the second confining pressure P2, but the magnitude relationship between the first confining pressure P1 and the second confining pressure P2 is not limited to this. The first confining pressure P1 and the second confining pressure P2 may be set independently of each other, taking into consideration the load caused by the pressing of the fluid injection nozzle 43 and the expansion force of the internal space S. As a result, the first confining pressure P1 may be smaller than the second confining pressure P2, or the first confining pressure P1 and the second confining pressure P2 may be equal.

[0090] In the above embodiment, when the power storage module 1 is placed in the decompression chamber 42, the power storage module 1 is placed on a flat pallet 48. However, the pallet 48 may be provided with a protrusion equivalent to the protrusion 65 of the second restraining member 45. In this case, the electrode stack 2 can be sandwiched between the pair of protrusions, which more reliably ensures that the second restraining member 45 contacts the electrode stack 2. Therefore, even if there is a large difference in size between the electrode stack 2 and the sealing body 3, the second restraining member 45 can more appropriately apply a restraining force to the electrode stack 2.

[0091] The sealing body 3 may be formed only by the sealing material 21, omitting the spacer 22. In this case, the communication hole 31 is formed by cutting out or drilling a hole in a part of the sealing material 21, and the welding end portion 23 is formed by welding the outer edge portions of the sealing materials 21 adjacent to each other in the stacking direction.

[0092] The first restraining member 44 and the second restraining member 45 do not necessarily have to be provided in the decompression chamber 42. For example, the first restraining member 44 and the second restraining member 45 may be provided on a pallet 48, and the workpiece, that is, the electricity storage module 1, may be restrained by the first restraining member 44 and the second restraining member 45 before being introduced into the decompression chamber 42.

[0093] The second restraining member 45 does not necessarily have to have the protrusion 65. Even in this case, the first region F1 of the sealing body 3, in which the plurality of communication holes 31 are provided, and the second region F2 including the internal space S can be restrained by the first restraining member 44 and the second restraining member 45 with mutually independent restraining pressures. Therefore, even if the electrode stack 2 and the sealing body 3 have different dimensions, the necessary restraining pressure can be applied to each of the first region F1 and the second region F2.

[0094] In the above embodiment, the internal space S of the electricity storage module 1 is evacuated simultaneously with the depressurization of the chamber 47. However, the internal space S may be evacuated via a nozzle separately from the depressurization of the chamber 47. The injection step may also be performed without disposing the electricity storage module 1 in the depressurization chamber 42. In this case, for example, a restraining jig having the first restraining member 44 and the second restraining member 45 may be attached to the workpiece electricity storage module 1 in advance, and then the injection step may be performed. The internal space S may be depressurized via a nozzle, or may not be depressurized at all. The nozzle that separately evacuates the internal space S may also serve as the fluid injection nozzle 43. In this case, for example, a switching unit that switches the connection between a tank of the fluid F and a vacuum pump may be provided at the base end of the fluid injection nozzle 43, and the connection of the fluid injection nozzle 43 may be switched between depressurizing the internal space S and injecting the fluid F.

[0095] As shown in FIG. 10 , the first restraining member 44 may restrain only the buildup portion 25 of the sealing body 3 with a first restraining pressure P1. In this case, when viewed from the first direction D1, the outer edge of the first region F1 restrained by the first restraining member 44 coincides with the outer edge of the buildup portion 25. In other words, the first region F1 may be a rectangular (here, oblong) region of the wall portion 3A that corresponds to the buildup portion 25. Because the multiple communication holes 31 are included in the buildup portion 25 when viewed from the first direction D1, the first region F1 in the example of FIG. 10 is also a region that includes the multiple communication holes 31. When the first region F1 corresponds to the buildup portion 25, the shape of the restraining plate 62 of the first restraining member 44 may be a rectangular shape that corresponds to the buildup portion 25.

[0096] When the first region F1 corresponds to the buildup portion 25, the second restraining member 45 may restrain the seal 3 in a region excluding the buildup portion 25 as the second region F2. In this case, the second region F2 includes the seal material 21 provided on the current collector 15 of the positive terminal electrode 12 and the negative terminal electrode 13 in a region excluding the buildup portion 25. In addition, the second region F2 includes a rectangular (here, oblong) region corresponding to the exposed portions R1 and R2 and the three wall portions 3B, 3C, and 3D of the seal 3 excluding the wall portion 3A. In other words, when viewed from the first direction D1, the second region F2 has a shape in which the region corresponding to the buildup portion 25 is cut out from the rectangle corresponding to the exposed portions R1 and R2 and the wall portions 3A, 3B, 3C, and 3D. In this case, the shape of the restraint plate 62 of the second restraint member 45 may be a rectangle corresponding to the exposed portions R1, R2 and the wall portions 3A, 3B, 3C, 3D, with the area corresponding to the buildup portion 25 cut out so as to match the shape of the second region F2.

[0097] In the manufacturing apparatus 41, the first region F1 and the second region F2 described above can be constrained with mutually independent constraining pressures by the first constraining member 44 and the second constraining member 45. Therefore, even if the electrode stack 2 and the sealing body 3 have different dimensions, it is possible to apply the necessary constraining pressure to each of the first region F1 and the second region F2.

[0098] As shown in FIG. 11, the first region F1 may include multiple regions. In the example of FIG. 11, the first region F1 includes a first dividing region F1a, a second dividing region F1b, and a third dividing region F1c. The first dividing region F1a may be a region corresponding to the buildup portion 25. The second dividing region F1b may be a region on one side of the opposing long sides of the plug 3 (the region on the wall portion 3C side) of the region of the wall portion 3A excluding the buildup portion 25. The third dividing region F1c may be a region on the other side of the opposing long sides of the plug 3 (the region on the wall portion 3D side) of the region of the wall portion 3A excluding the buildup portion 25.

[0099] When the first region F1 includes multiple regions, the first constraining member 44 may have multiple cylinders and multiple constraining plates corresponding to the multiple regions. The first constraining member 44 may then independently control the constraining pressure for each of the multiple regions. For the first region F1 shown in FIG. 11, the first constraining member 44 may have a constraining plate and cylinder for constraining the first divided region F1a, a constraining plate and cylinder for constraining the second divided region F1b, and a constraining plate and cylinder for constraining the third divided region F1c. In this case, the first constraining member 44 may independently control the constraining pressure for the first divided region F1a, the second divided region F1b, and the third divided region F1c. This allows the necessary constraining pressure to be applied to each of the first divided region F1a, the second divided region F1b, and the third divided region F1c, even if the electrode stack 2 and the sealing body 3 have different dimensions. [Explanation of symbols]

[0100] 1...energy storage module, 2...electrode stack, 3...sealing body, 11...bipolar electrode (electrode), 12...positive terminal electrode (electrode), 13...negative terminal electrode (electrode), 15...current collector, 15c...periphery, 21...sealing material, 22...spacer, 22a...edge, 23s...side, 31...communicating hole, 31A...opening, 41, 71...manufacturing apparatus, 42...decompression chamber, 43...fluid injection nozzle, 44 (44A, 44B)...first constraining member, 45...second constraining member, 65...convex portion, F...fluid, F1...first region, F2...second region, P1...first constraining pressure, P2...second constraining pressure, R1, R2...exposed portion, S...internal space.

Claims

1. an electrode stack in which a plurality of electrodes, each including a current collector, are stacked; a sealing body provided on a peripheral portion of each of the current collectors so as to surround the electrode stack, the sealing body sealing a plurality of internal spaces located between the current collectors adjacent to each other in the stacking direction, and the sealing body having a plurality of communication holes communicating with each of the plurality of internal spaces, a fluid injection nozzle that is pressed against the periphery of the opening of the communication hole on the side surface of the sealing body to inject a fluid into each of the plurality of internal spaces through the communication hole; a first restraining member that restrains a first region of the sealing body in which the plurality of communication holes are provided; a second restraining member that is provided independently of the first restraining member and that restrains a second region including the internal space in the stacking direction.

2. The energy storage module manufacturing apparatus according to claim 1 , wherein a first confinement pressure applied by the first confinement member is greater than a second confinement pressure applied by the second confinement member.

3. the sealing body includes a plurality of sealing materials covering peripheral portions of the current collectors, and a spacer interposed between the sealing materials adjacent to each other in the stacking direction; The energy storage module manufacturing apparatus according to claim 1 , wherein the first restraining member restrains an area where the sealing material and the spacer overlap in the stacking direction as the first area.

4. a decompression chamber in which the power storage module is disposed; The energy storage module manufacturing apparatus according to claim 1 , wherein the first restraining member and the second restraining member are respectively provided in the decompression chamber.

5. a decompression chamber in which the power storage module is disposed; The first restraint member is provided in the decompression chamber, The energy storage module manufacturing apparatus according to claim 1 or 2, wherein a wall portion of the decompression chamber constitutes the second restraining member.

6. The energy storage module manufacturing device according to claim 1 , wherein the second restraining member is provided with a protrusion corresponding to an exposed portion of the electrode stack from the sealing body.

7. an electrode stack in which a plurality of electrodes, each including a current collector, are stacked; a sealing body provided on a peripheral portion of each of the current collectors so as to surround the electrode stack, the sealing body sealing a plurality of internal spaces located between the current collectors adjacent to each other in the stacking direction, and the sealing body having a plurality of communication holes communicating with each of the plurality of internal spaces, an injection step of pressing a fluid injection nozzle against the periphery of the opening of the communication hole on the side surface of the sealing body, and injecting a fluid into each of the plurality of internal spaces through the communication hole; In the injection step, a first region of the sealing body, in which the plurality of communication holes are provided, is restrained by a first restraining member; a second region including the internal space is constrained in the stacking direction by a second constraining member provided independently of the first constraining member;

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