Method for manufacturing electric power storage module

Abstract

This method for manufacturing an electric power storage module comprises: a step (S101) for bonding a detection line (60) to a surface (15b) of a collector (15); a step (S102) for disposing a seal member (71) on the surface (15b) and the detection line (60); and a step (S103, S104) for bonding the seal member (71) to the surface (15b) and the detection line (60). In the step (S103), the seal member (71) is bonded by heating and melting the seal member (71) in a first region (R1) of the seal member (71) that overlaps the detection line (60) and the periphery of the detection line (60). In the step (S104), the seal member (71) is bonded by heating and melting the seal member (71) in a second region (R2) different from the first region (R1).

Description

Energy storage module manufacturing method

[0001] The present disclosure relates to a method for manufacturing an electricity storage module.

[0002] Patent Document 1 describes a bipolar secondary battery. This bipolar secondary battery has a battery element formed by stacking unit cells. Each unit cell includes a positive electrode, a negative electrode, a separator, and an insulating member. This bipolar secondary battery has a voltage detection terminal disposed on the outer periphery of the battery element, between the insulating member and the negative electrode current collector, in contact with the negative electrode current collector, for detecting the voltage of the unit cell.

[0003] Japanese Patent Application Laid-Open No. 2020-061221

[0004] In the bipolar secondary battery described in Patent Document 1, welding of the insulating member to the current collector involves applying pressure to the current collector to which a terminal having a certain thickness is attached. While sufficient surface pressure is applied to the insulating member in the area of ​​the insulating member that overlaps the terminal (the area that protrudes by the thickness of the terminal), there is a risk that sufficient surface pressure is not applied to the area of ​​the insulating member surrounding the terminal. In this case, there is a risk of a gap occurring between the current collector and the insulating member in the area surrounding the terminal.

[0005] Therefore, an object of the present invention is to provide a method for manufacturing an energy storage module that can prevent gaps from occurring in the area around the terminals.

[0006] A method for manufacturing an electric storage module according to the present invention is a method for manufacturing an electric storage module including: an electrode stack including a plurality of electrodes stacked along a first direction; a sealing body provided on the electrode stack so as to surround the electrode stack by stacking a plurality of sealing members provided on each of the plurality of electrodes along the first direction, the sealing body being for sealing a plurality of internal spaces formed between the electrodes adjacent in the first direction; and a plurality of terminals joined to each of the plurality of electrodes and drawn out to the sealing body, the method comprising the steps of: a terminal joining step of joining the terminals to first surfaces of the electrodes at peripheral edges of the electrodes; a seal arrangement step of arranging a first seal member, which is a sealing member, on the first surface and the terminals at the peripheral edges; and a seal arrangement step of heating and melting the first seal member to seal the first surface and the terminals. and a seal joining process for joining a first seal member, wherein in the terminal joining process, the terminal is joined to the first surface so that the terminal is pulled out of the electrode when viewed from a second direction intersecting the first surface, and in the seal placement process, the first seal member is placed so that, when viewed from the second direction, the first seal member includes an inner portion that overlaps the electrode and an outer portion that does not overlap the electrode, and the inner portion, when viewed from the second direction, includes a first region that overlaps the terminal and the first surface around the terminal, and a second region that is continuous with the first region and overlaps the first surface, and the seal joining process includes a first joining process for joining the first seal member to the terminal and joining the first seal member to the first surface around the terminal in the first region, and a second joining process for joining the first seal member to the first surface in the second region after the first joining process.

[0007] In this manufacturing method, first, a terminal is bonded to a first surface of an electrode. At this time, the terminal is bonded to the first surface so that the terminal is extended outside the electrode when viewed from a second direction intersecting the first surface. A first sealing member is then disposed on the first surface of the electrode and the terminal. When viewed from the second direction, the first sealing member includes an inner portion overlapping the electrode and an outer portion not overlapping the electrode, and is disposed so as to contact the first surface and the terminal. When viewed from the second direction, the inner portion includes a first region overlapping the terminal and its periphery and a second region continuous with the first region. The first sealing member is then heated and melted to bond the first sealing member to the first surface and the terminal. In this seal bonding process, first, the first sealing member is bonded to the terminal in the first region overlapping the terminal and its periphery, and the first sealing member is bonded to the first surface around the terminal. Then, the first seal member is bonded to the first surface in a second region that is continuous with the first region. In this way, when bonding the seal member to the electrode to which the terminal is bonded, the terminal and the first region around the terminal are melted and bonded before the second region, thereby preventing a gap from occurring between the electrode and the seal member in the region around the terminal.

[0008] In the energy storage module manufacturing method according to the present invention, in the second joining step, the sealing member may be heated simultaneously in the first region and the second region so that the heat input to the second region is greater than the heat input to the first region, thereby joining the sealing member.

[0009] In the energy storage module manufacturing method of the present invention, the thickness of the sealing member in the second direction may be greater than the thickness of the terminal in the second direction, and in the first joining process, the first sealing member may be heated so that the difference in the second direction between the height of the first sealing member from the first surface in the first region and the height of the first sealing member from the first surface in the second region is smaller than the thickness of the terminal.

[0010] In the energy storage module manufacturing method of the present invention, in the seal placement process, a second seal member is placed so as to overlap the inner portion when viewed from the second direction and to contact a second surface opposite the first surface of the electrode, and in the first joining process, heaters may be pressed against each of the first seal member and the second seal member from both the first surface and the second surface.

[0011] In the energy storage module manufacturing method according to the present invention, in the seal joining process, the outer portion includes a third region that includes the outer edge of the first seal member when viewed from the second direction, and a rectangular frame-shaped fourth region that is located between the third region and the inner portion when viewed from the second direction, and in the first joining process, the first seal member may be joined so as to prevent the third region from melting.

[0012] In the energy storage module manufacturing method of the present invention, in the seal placement process, a second seal member is placed so as to overlap the inner portion and the fourth region when viewed from the second direction in the seal joining process, and to contact the second surface opposite the first surface of the electrode, and in the first joining process, the first seal member and the second seal member may be welded together in the fourth region.

[0013] The energy storage module manufacturing method according to the present invention may further include, after the seal joining process, an integration process in which a plurality of units each made up of an electrode and a sealing member joined to the electrode are stacked along a first direction, and the sealing members of the plurality of units stacked on top of each other are integrated to form an electrode stack and a sealing body.

[0014] In the energy storage module manufacturing method of the present invention, in the integration process, the sealing members of the multiple units stacked on top of each other may be integrated with each other by welding the outer edges of the sealing members of the multiple units to each other when viewed from a first direction.

[0015] In the energy storage module manufacturing method according to the present invention, in the second joining step, the sealing member may be joined so that the amount of heat input to the second region is greater than the amount of heat input to the first region.

[0016] In the energy storage module manufacturing method according to the present invention, the first surface has a rectangular shape including four side portions, and the seal joining process includes a third joining process in which a seal member is joined to a second side portion of the four side portions of the first surface other than the first side portion to which the terminal is joined, and in the second joining process, when joining the seal member to the first side portion of the four side portions of the first surface, a greater surface pressure may be applied to the seal member compared to the third joining process.

[0017] In the method for manufacturing an electric storage module according to the present invention, in the seal joining step, the seal member may be heated by pressing a heater against the seal member via a glass cloth.

[0018] In the energy storage module manufacturing method of the present invention, the first region is composed of an overlapping region that overlaps with the terminal when viewed from the second direction, and a non-overlapping region that does not overlap with the terminal when viewed from the second direction, and the non-overlapping region includes, when viewed from a direction intersecting the second direction, a region between the overlapping region and each of the contact points where the first sealing member extends from both ends of the overlapping region on the terminal toward the first surface and contacts the first surface, and in the first joining process, the first sealing member may be joined to the terminal in the overlapping region and the first surface in the non-overlapping region.

[0019] According to the present invention, it is possible to provide a method for manufacturing an energy storage module that can prevent gaps from occurring in the area around the terminals.

[0020] FIG. 1 is a schematic plan view of an energy storage module according to one embodiment. FIG. 2 is a schematic side view showing an enlarged view of a portion of the energy storage module shown in FIG. 1. FIG. 3 is a schematic cross-sectional view taken along line III-III in FIG. 2. FIG. 4 is a flowchart showing one step of a method for manufacturing an energy storage module according to the present embodiment. FIG. 5 is a schematic view showing one of the steps shown in FIG. 4. FIG. 5(a) is a cross-sectional view, and FIG. 5(b) is a plan view. FIG. 6 is a schematic view showing one of the steps shown in FIG. 4. FIG. 6(a) is a plan view, and FIG. 6(b) is a cross-sectional view. FIG. 7 is a schematic plan view showing one of the steps shown in FIG. 4. FIG. 8 is a schematic cross-sectional view showing one of the steps shown in FIG. 4. FIG. 9 is a schematic cross-sectional view showing an enlarged view of a portion of FIG. 8. FIG. 10 is a schematic view showing one of the steps shown in FIG. 4. FIG. 10(a) is a cross-sectional view, and FIG. 10(b) is an enlarged cross-sectional photograph. FIG. 11 is a schematic cross-sectional view showing one of the steps shown in FIG.

[0021] An embodiment of the present invention will be described below with reference to the drawings. In the description of each drawing, the same or corresponding elements are given the same reference numerals, and redundant description may be omitted. In addition, each drawing may show an orthogonal coordinate system consisting of an X-axis, a Y-axis, and a Z-axis.

[0022] Fig. 1 is a schematic plan view of an energy storage module according to one embodiment. Fig. 2 is a schematic side view showing an enlarged portion of the energy storage module shown in Fig. 1. Fig. 3 is a schematic cross-sectional view taken along line III-III in Fig. 2. The liquid injection port shown in Figs. 1 and 2 and the sealing member shown in Fig. 1 are omitted from Fig. 3.

[0023] 1 to 3 is mounted on, for example, a forklift, a hybrid vehicle, or an electric vehicle. The power storage module 1 is, for example, a nickel-metal hydride secondary battery or a lithium-ion secondary battery. The power storage module 1 may also be, for example, an electric double layer capacitor. In this embodiment, the power storage module 1 is a lithium-ion secondary battery.

[0024] The energy storage module 1 includes an electrode stack 10, a sealing body 20, a sealing member 30, and a plurality of detection lines (terminals) 60. The electrode stack 10 includes a plurality of electrodes stacked along the Z-axis direction. The electrode stack 10 has, for example, a rectangular parallelepiped shape.

[0025] The sealing body 20 has a liquid injection port 50 formed therein. The sealing body 20 is provided on the peripheral edge of the electrode stack 10. The sealing body 20 seals the side surface of the electrode stack 10. The sealing body 20 has, for example, a rectangular cylindrical shape. The sealing body 20 has electrical insulation properties.

[0026] The liquid inlet portion 50 is provided in a region of the sealing body 20 where a liquid inlet 20a (described later) is formed. The liquid inlet portion 50 is provided on a side surface 20c of the sealing body 20. The width of the liquid inlet portion 50 in the X-axis direction is smaller than the width of the sealing body 20 in the X-axis direction. Both ends of the liquid inlet portion 50 in the X-axis direction are located inside both ends of the sealing body 20 in the X-axis direction. The liquid inlet portion 50 includes a side wall portion 51, an overhang portion 52, an overhang portion 53, a frame portion 54, and a thin-walled portion 55.

[0027] The sidewall portion 51 is provided on the side surface 20c of the sealing body 20. The sidewall portion 51 has, for example, a rectangular plate shape. The overhang portion 52 is provided on one end surface of the sealing body 20 in the Z-axis direction. The overhang portion 52 has, for example, a rectangular plate shape. The overhang portion 53 is provided on the other end surface of the sealing body 20 in the Z-axis direction. The overhang portion 53 has, for example, a rectangular plate shape.

[0028] The liquid inlet portion 50 includes multiple frame portions 54. The frame portions 54 protrude from the side surfaces of the sidewall portions 51. When viewed from the Y-axis direction, the frame portions 54 surround each of the liquid inlets 20a lined up in the Z-axis direction. Thin-walled portions 55 are provided on the side surfaces of the sidewall portions 51 on both sides of the sidewall portions 51 in the X-axis direction. The thin-walled portions 55 extend along the Z-axis direction. The thin-walled portions 55 reach both ends of the sidewall portions 51 in the Z-axis direction. The thickness of the thin-walled portions 55 is smaller than the thickness of the sidewall portions 51. The sidewall portions 51, the overhanging portions 52 and 53, the frame portions 54, and the thin-walled portions 55 are each a partial region of the liquid inlet portion 50 integrated from the same material. The liquid inlet portion 50 is formed, for example, by injection molding.

[0029] The sealing body 20 includes a plurality of liquid injection ports 20a. The liquid injection ports 20a communicate with the internal space S of the electrode stack 10. The liquid injection ports 20a function as paths for injecting the electrolyte into the internal space S. The sealing body 20 has a plurality of liquid injection port rows. The plurality of liquid injection port rows are aligned in the Z-axis direction. Each liquid injection port row includes a plurality of liquid injection ports 20a aligned in the X-axis direction. Each liquid injection port row includes, for example, ten liquid injection ports 20a. When viewed from the Y-axis direction, in each liquid injection port row, the plurality of liquid injection ports 20a are aligned diagonally with respect to the X-axis direction. In each liquid injection port row, the liquid injection ports 20a are spaced apart from each other in the X-axis direction.

[0030] The sealing member 30 has, for example, a plate shape. When viewed from the X-axis direction, the sealing member 30 overlaps with the multiple frame portions 54. The sealing member 30 is, for example, a laminate sheet or the like. The sealing member 30 includes, for example, a metal layer and a resin layer. The material of the metal layer is, for example, aluminum. The sealing member 30 is welded to the tips of the multiple frame portions 54. This seals the multiple liquid injection ports 20a. Note that the sealing member 30 is not shown in FIG. 2.

[0031] The multiple detection wires 60 are located adjacent to the multiple frame portions 54 when viewed from the Y-axis direction. The detection wires 60 are used to detect the battery state of the energy storage module 1. In this embodiment, the voltage between adjacent electrodes of the energy storage module 1 is detected by an external device via the detection wires 60. That is, the detection wires 60 are, for example, voltage detection wires (i.e., include terminals for voltage detection). The detection wires 60 protrude from the side wall portion 51. Each detection wire 60 is joined to a respective current collector 15, which will be described later.

[0032] The energy storage module 1 has a plurality of detection line arrays 61. Each detection line array 61 has a plurality of detection lines 60 lined up in the Z-axis direction. That is, the plurality of detection lines 60 constituting one detection line array 61 overlap one another when viewed in the Z-axis direction. The plurality of detection line arrays 61 are lined up along the X-axis direction at predetermined intervals. The positions of the detection lines 60 in the Z-axis direction are shifted from one another. In this embodiment, the detection line arrays 61 are positioned closer to the negative terminal electrode 13 (described later) (lower side in FIG. 2 ) as they move away from the frame portion 54 in the X-axis direction.

[0033] When focusing on a pair of adjacent detection line arrays 61 in the X-axis direction, for example, one detection line 60 of one detection line array 61 is located closer to the positive electrode terminal electrode 12 (upper side in FIG. 2 ), which will be described later, than another detection line 60 of another detection line array 61 that is located on the opposite side of the frame portion 54 from the one detection line array 61. Note that the one detection line 60 is the Nth (N is a natural number) detection line of the one detection line array 61 when counted from the positive electrode terminal electrode 12 side, and the other detection line 60 is the Nth (N is a natural number) detection line of the other detection line array 61 when counted from the positive electrode terminal electrode 12 side.

[0034] The electrode stack 10 has a plurality of bipolar electrodes 11, a positive terminal electrode 12, a negative terminal electrode 13, and a plurality of separators 14. The plurality of bipolar electrodes 11, the positive terminal electrodes 12, the negative terminal electrodes 13, and the plurality of separators 14 are stacked along the Z-axis direction (first direction). That is, the electrode stack includes a plurality of electrodes (bipolar electrodes 11, positive terminal electrodes 12, negative terminal electrodes 13) stacked along the Z-axis direction.

[0035] The bipolar electrode 11 includes a current collector 15, a first active material layer 16, and a second active material layer 17. When viewed from the Z-axis direction, the current collector 15 has, for example, a rectangular shape. The current collector 15 includes a surface 15a (second surface) and a surface 15b (first surface) opposite to the surface 15a.

[0036] The first active material layer 16 is provided on the surface 15a. The first active material layer 16 is, for example, a positive electrode active material layer. When viewed from the Z-axis direction, the first active material layer 16 has, for example, a rectangular shape. The surface 15a includes an unformed region where the first active material layer 16 is not provided. When viewed from the Z-axis direction, the unformed region surrounds the first active material layer 16.

[0037] The second active material layer 17 is provided on the surface 15b. The polarity of the second active material layer 17 is different from the polarity of the first active material layer 16. The second active material layer 17 is, for example, a negative electrode active material layer. When viewed from the Z-axis direction, the second active material layer 17 has, for example, a rectangular shape. The surface 15b includes an unformed region where the second active material layer 17 is not provided. When viewed from the Z-axis direction, the unformed region surrounds the second active material layer 17. When viewed from the Z-axis direction, the area of ​​the second active material layer 17 is larger than the area of ​​the first active material layer 16. When viewed from the Z-axis direction, the outer edge of the second active material layer 17 is located outside the outer edge of the first active material layer 16.

[0038] The multiple bipolar electrodes 11 are stacked such that the first active material layer 16 of one bipolar electrode 11 faces the second active material layer 17 of another bipolar electrode 11. In other words, the multiple bipolar electrodes 11 are stacked such that, of adjacent bipolar electrodes 11, the surface 15a of the current collector 15 of one bipolar electrode 11 faces the surface 15b of the current collector 15 of the other bipolar electrode 11.

[0039] The positive terminal electrode 12 is disposed on one side of the plurality of bipolar electrodes 11 in the Z-axis direction. The positive terminal electrode 12 includes a current collector 15 and a first active material layer 16. The positive terminal electrode 12 differs from the bipolar electrode 11 primarily in that it does not include a second active material layer 17. The other configuration of the positive terminal electrode 12 may be the same as that of the bipolar electrode 11. The first active material layer 16 of the positive terminal electrode 12 faces the second active material layer 17 of the bipolar electrode 11. That is, the positive terminal electrode 12 is stacked such that the surface 15a of the current collector 15 of the positive terminal electrode 12 faces the surface 15b of the current collector 15 of the bipolar electrode 11 adjacent to the positive terminal electrode 12.

[0040] The negative electrode terminal electrode 13 is disposed on the other side of the plurality of bipolar electrodes 11 in the Z-axis direction. The negative electrode terminal electrode 13 includes a current collector 15 and a second active material layer 17. The negative electrode terminal electrode 13 differs from the bipolar electrode 11 mainly in that it does not include a first active material layer 16. The other configuration of the negative electrode terminal electrode 13 may be the same as that of the bipolar electrode 11. The second active material layer 17 of the negative electrode terminal electrode 13 faces the first active material layer 16 of the bipolar electrode 11. That is, the negative electrode terminal electrode 13 is stacked such that the surface 15b of the current collector 15 of the negative electrode terminal electrode 13 faces the surface 15a of the current collector 15 of the bipolar electrode 11 adjacent to the negative electrode terminal electrode 13.

[0041] The outer edges of the current collectors 15 of each electrode form the side surfaces of the electrode stack 10. Internal spaces S for accommodating an electrolyte are formed between each bipolar electrode 11, between the bipolar electrode 11 and the positive terminal electrode 12, and between the bipolar electrode 11 and the negative terminal electrode 13.

[0042] Separators 14 are disposed between each bipolar electrode 11, between the bipolar electrode 11 and the positive terminal electrode 12, and between the bipolar electrode 11 and the negative terminal electrode 13. The separators 14 are disposed between the opposing first and second active material layers 16 and 17. The separators 14 are, for example, sheet-shaped. When viewed from the Z-axis direction, the outer edges of the separator 14 are located further outward than the outer edges of the first and second active material layers 16 and 17. The separators 14 allow charge carriers such as lithium ions to pass through. The separators 14 separate adjacent electrodes, thereby preventing electrical shorts due to contact between the electrodes. The separators 14 absorb and retain the electrolyte.

[0043] The current collector 15 has the function of maintaining the flow of current in the first active material layer 16 and the second active material layer 17 during discharging or charging of the energy storage module 1. The current collector 15 is, for example, a chemically inactive electrical conductor. The material of the current collector 15 is, for example, a metal material, a conductive resin material, a conductive inorganic material, etc. The conductive resin material is, for example, a conductive polymer material, or a non-conductive polymer material to which a conductive filler has been added. When the current collector 15 has multiple layers, the material of each layer may be any of the materials described above. 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.

[0044] The current collector 15 has, for example, a plate, foil, sheet, film, or mesh shape. The current collector 15 may be, for example, an aluminum foil, copper foil, nickel foil, titanium foil, or stainless steel foil. The current collector 15 may be an alloy foil or clad foil of the above metals. When the current collector 15 is foil-shaped, the thickness of the current collector 15 is, for example, 1 μm or more and 100 μm or less. The current collector 15 may be a laminate having multiple metal layers. The current collector 15 may be, for example, a laminate in which an aluminum layer and a copper layer are integrated. The current collector 15 may include, for example, an aluminum foil and copper plating formed on one side of the aluminum foil. The current collector 15 may include multiple metal foils bonded together with a conductive adhesive.

[0045] The first active material layer 16 includes a positive electrode active material capable of absorbing and releasing charge carriers such as lithium ions. The positive electrode active material is, for example, a composite oxide, metallic lithium, or sulfur. The composite oxide includes, for example, at least one of iron, manganese, titanium, nickel, cobalt, and aluminum, and lithium. The composite oxide is, for example, olivine-type lithium iron phosphate (LiFePO ４ ), LiCoO ２ , LiNiMnCoO ２ etc.

[0046] The second active material layer 17 includes a negative electrode active material capable of absorbing and releasing charge carriers such as lithium ions. Examples of the negative electrode active material include graphite, artificial graphite, highly oriented graphite, mesocarbon microbeads, hard carbon, soft carbon, metal compounds, elements or compounds thereof that can be alloyed with lithium, and boron-doped carbon. Examples of the elements that can be alloyed with lithium include silicon and tin.

[0047] Each of the first active material layer 16 and the second active material layer 17 may contain a binder and a conductive additive in addition to the active material. The binder functions to bind the active material or conductive additive together and maintain the conductive network in the electrode. 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 polyacrylic acid and polymethacrylic acid; styrene-butadiene rubber; 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. The conductive additive is a conductive material that enhances electrical conductivity. Examples of conductive additives include acetylene black, carbon black, and graphite. Examples of viscosity-adjusting solvents include N-methyl-2-pyrrolidone.

[0048] Formation of the first active material layer 16 on the surface 15a and the second active material layer 17 on the surface 15b can be achieved by conventional methods such as roll coating, die coating, dip coating, doctor blade coating, spray coating, and curtain coating. Specifically, an active material, a solvent, and, if necessary, a binder and a conductive additive are mixed to produce a slurry-like active material layer-forming composition, which is then applied to the surface 15a or the surface 15b and dried. Examples of the solvent include N-methyl-2-pyrrolidone, methanol, methyl isobutyl ketone, and water. The dried electrode may be compressed to increase electrode density.

[0049] The electrolyte solution is accommodated in the internal space S. The separator 14 is impregnated with the electrolyte solution. The electrolyte solution is, for example, a liquid containing a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent. The electrolyte salt of the electrolyte solution is, for example, LiClO ４ , LiAsF ６ , LiPF ６ , LiBF ４ , LiCF ３ SO ３ , LiN(FSO ２ ) ２ , LiN(CF ３ SO ２ ) ２ The non-aqueous solvent is a cyclic carbonate, a cyclic ester, a chain carbonate, a chain ester, an ether, etc. Two or more of these known solvent materials may be used in combination.

[0050] The sealing body 20 has a sealing member 41, a spacer 42, and a welded portion 43. The sealing member 41 has, for example, a rectangular frame shape. The sealing member 41 is provided on the peripheral portion 15c of each current collector 15 and covers the peripheral portion 15c. The sealing member 41 is provided on the surface 15a and the surface 15b of each current collector 15. The sealing member 41 is formed in a frame shape so as to surround the first active material layer 16 and the second active material layer 17 when viewed from the Z-axis direction. The inner edge of the sealing member 41 is spaced from the first active material layer 16 and the second active material layer 17. The sealing member 41 is welded to the current collector 15.

[0051] The spacer 42 has, for example, a rectangular frame shape. The spacer 42 is provided between adjacent sealing members 41. The spacer 42 is sandwiched between adjacent sealing members 41. The inner peripheral portion of the spacer 42 overlaps with the second active material layer 17 when viewed from the Z-axis direction. The inner peripheral portion of the spacer 42 is located between the surface 15a of the current collector 15 and the second active material layer 17. The welded portion 43 is formed by welding and integrating the outer edges of each sealing member 41 and each spacer 42. The welded portion 43 has, for example, a rectangular cylindrical shape.

[0052] In this way, in the energy storage module 1, the sealing members 41 provided on each electrode are stacked along the Z-axis direction via spacers 42 so as to surround the electrode stack 10, thereby forming a sealing body 20 for sealing the internal space S formed between adjacent electrodes in the Z-axis direction.

[0053] The sealing member 41 and the spacer 42 are made of materials such as acid-modified polyethylene (acid-modified PE), acid-modified polypropylene (acid-modified PP), polyethylene, or polypropylene. The sealing member 41 and the spacer 42 are both electrolyte-resistant. The materials of the sealing member 41 and the spacer 42 may be the same or different. In this embodiment, the sealing member 41 is made of, for example, acid-modified polyethylene or acid-modified polypropylene. In this embodiment, the spacer 42 is made of, for example, polyethylene or polypropylene. Acid-modified polyethylene and acid-modified polypropylene are more easily bonded to metal than non-acid-modified polyethylene and non-acid-modified polypropylene. When the current collector 15 is made of metal, the bonding strength of the sealing member 41 to the current collector 15 can be improved by forming the sealing member 41 from acid-modified polyethylene or acid-modified polypropylene.

[0054] The detection wires 60 are bonded to the surfaces 15b of the current collectors 15 and are electrically connected to the surfaces 15b. The detection wires 60 are located between the surfaces 15b of the current collectors 15 and the seal member 41. The detection wires 60 pass through the sealing body 20 and are drawn out to the outside of the sealing body 20. The detection wires 60 are made of, for example, a metal. The detection wires 60 are, for example, stainless steel foil.

[0055] Next, a description will be given of a method for manufacturing an energy storage module according to this embodiment. In this embodiment, the above-described energy storage module 1 is manufactured. FIG. 4 is a flowchart showing one step of the method for manufacturing an energy storage module according to this embodiment. FIGS. 5 to 11 are schematic diagrams showing the steps shown in FIG. 4. Note that the Cartesian coordinate systems shown in FIGS. 5 to 11 are the same as the Cartesian coordinate systems shown in FIGS. 1 to 3 for ease of understanding, but the directions during manufacturing do not need to match the directions in the manufactured energy storage module 1.

[0056] 4 and 5 , in the method for manufacturing an energy storage module according to this embodiment, a first electrode unit U1 is constructed by first joining a detection wire 60 to an electrode (step S101: terminal joining step). In the illustrated example, a bipolar electrode 11 is prepared, and the detection wire 60 is joined (e.g., welded) to the surface 15b of the peripheral portion 15c of the current collector 15 of the bipolar electrode 11, thereby constructing the first electrode unit U1 including the bipolar electrode 11. At this time, the detection wire 60 is joined to the surface 15b so that the detection wire 60 is drawn out of the current collector 15 (i.e., the bipolar electrode 11) when viewed from the Z-axis direction (second direction) intersecting the surface 15b.

[0057] In this embodiment, the surface 15b has a rectangular shape including four sides. In step S101, the detection wire 60 is joined to a first side 151 of the four sides of the surface 15b. That is, the detection wire 60 is drawn from the first side 151 to the outside of the current collector 15 when viewed in the Z-axis direction. Note that in step S101, the detection wire 60 is also joined to the positive terminal electrode 12 and the negative terminal electrode 13 in a similar manner, thereby forming a first electrode unit U1 including each of the positive terminal electrode 12 and the negative terminal electrode 13.

[0058] 4, 6, and 7, a seal member 41 is placed on the surface 15b and the detection line 60 in the peripheral portion 15c of the current collector 15 of the first electrode unit U1, thereby forming the second electrode unit U2 (step S102: seal placement step). More specifically, in step S102, a seal member 71 (first seal member) that will become the seal member 41 is placed on the surface 15b side, and a seal member 72 (second seal member) that will become the seal member 41 is placed on the surface 15a side. The seal members 71 and 72 are integrated into one another in a later step to become the seal member 41.

[0059] Here, in step S102, a sealing member 71 is placed on the surface 15b and the detection lines 60 in the peripheral portion 15c of the current collector 15, and also on the surface 15a. In particular, in step S102, the sealing member 71 is placed on the surface 15b and the detection lines 60 so that, when viewed from the Z-axis direction, the sealing member 71 includes an inner portion 71a that overlaps the current collector 15 (i.e., the bipolar electrode 11) and an outer portion 71b that does not overlap the current collector 15 and is located outside the current collector 15, and so that the detection lines 60 are drawn to the outside of the sealing member 71. At this time, the sealing member 71 is in contact with the surface 15b and the detection lines 60. As a result, the sealing member 71 includes a first region R1, a second region R2, a third region R3, and a fourth region R4.

[0060] The first region R1 and the second region R2 are regions within the inner portion 71a. That is, the inner portion 71a includes the first region R1 and the second region R2. In this embodiment, the inner portion 71a is configured by the first region R1 and the second region R2. The first region R1 is configured by an overlapping region Ra that overlaps the detection line 60 in the inner portion 71a when viewed from the Z-axis direction (a second direction intersecting the surface 15b) and a non-overlapping region Rb that does not overlap the detection line 60 (i.e., overlaps with the surface 15b around the detection line 60). The second region R2 is a region different from the first region R1 in the inner portion 71a when viewed from the Z-axis direction, is a region surrounding the first region R1 that is continuous with the first region R1 and overlaps with the surface 15b.

[0061] The third region R3 and the fourth region R4 are regions within the outer portion 71b. That is, the outer portion 71b includes the third region R3 and the fourth region R4. In this embodiment, the outer portion 71b consists of the third region R3 and the fourth region R4. The third region R3 is located opposite the inner portion 71a when viewed from the Z-axis direction and is a region that includes the outer edge 71e of the sealing member 71. The third region R3 does not reach the inner portion 71a when viewed from the Z-axis direction. The fourth region R4 is a region that is located between the third region R3 and the inner portion 71a when viewed from the Z-axis direction. In the sealing member 71, at least the second region R2, the third region R3, and the fourth region R4 are elongated regions that extend along the first side portion 151 of the current collector 15.

[0062] In step S102, the seal member 72 is disposed so as to overlap the inner portion 71a and the outer portion 71b of the seal member 71 when viewed from the Z-axis direction and so as to be in contact with the surface 15a.

[0063] In the next step, the sealing member 71 is heated and melted to bond the sealing member 71 to the surface 15b of the collector 15 of the second electrode unit U2 and the detection line 60 on the surface 15b, and the sealing member 72 is heated and melted to bond the sealing member 72 to the surface 15a of the collector 15, thereby forming the third electrode unit U3 (see Figure 9) (steps S103 and S104: sealing and bonding step).

[0064] 4, 8, and 9, a first stage of bonding of the sealing members 71 and 72 is performed (step S103: first bonding step). In step S103, the second electrode unit U2 is first placed between a pair of jigs Z1, such as aluminum blocks, for applying pressure to the second electrode unit U2. A pair of elastic members Z2, such as silicone rubber, are placed between the pair of jigs Z1, and a pair of glass tapes Z3 are placed between the pair of elastic members Z2. A pair of heaters Z4 are placed between the pair of glass tapes Z3, and a pair of glass cloths Z5 are placed between the pair of heaters Z4. The heaters Z4 are, for example, ribbon heaters, and are capable of impulse heating.

[0065] The second electrode unit U2 is disposed between a pair of glass cloths Z5. Thus, in this embodiment, the sealing members 71 and 72 of the second electrode unit U2 each receive heat input from the heater Z4 via the glass cloth Z5. That is, in step S103, the heater Z4 is pressed against the sealing members 71 and 72 via the glass cloth Z5, thereby heating and melting the sealing members 71 and 72. Note that the elastic member Z2 on the surface 15a side of the current collector 15 of the second electrode unit U2 (the side on which the detection line 60 is not provided) may be omitted.

[0066] In step S103, the seal member 71 is heated and melted in a first region R1 of the seal member 71, thereby bonding the seal member 71 to the surface 15b and the detection line 60. As shown in FIG. 9 , the overlapping region Ra of the first region R1 is a region located on the detection line 60 when viewed from the Y-axis direction intersecting the Z-axis direction (second direction). Furthermore, the non-overlapping region Rb of the first region R1 includes, when viewed from the Y-axis direction, a region between the overlapping region Ra and each of the contact points CP where the seal member 71 extends from both ends of the overlapping region Ra on the detection line 60 toward the surface 15b and contacts the surface 15b. In step S103, the seal member 72 is heated and melted in a region of the seal member 72 that overlaps the first region R1 of the seal member 71 along the Z-axis direction, thereby bonding the seal member 72 to the surface 15a.

[0067] 10A, in step S103, the heater Z4 is disposed in an area overlapping the first region R1 of the sealing member 71 of the second electrode unit U2 along the Z-axis direction (a second direction intersecting the surface 15b). Therefore, in step S103, the heater Z4 is pressed against the sealing members 71 and 72 from both the surface 15a and the surface 15b of the current collector 15 (through the glass cloth Z5) by a pressing force from the jig Z1. While the heater Z4 is pressed against the sealing members 71 and 72 (through the glass cloth Z5) from both the surface 15a and the surface 15b of the current collector 15, the sealing member 71 is heated and melted (i.e., bonded) only in the first region R1 of the first, second, third, and fourth regions R1, and the sealing member 72 is heated and melted (i.e., bonded) in the corresponding region of the sealing member 72. As a result, as shown in FIG. 10B, the molten resin of the sealing member 71 fills the corner between the current collector 15 and the detection line 60. In FIG. 10A, the components between the pair of jigs Z1 are omitted from the illustration except for the elastic member Z2 and the heater Z4.

[0068] In this embodiment, in step S103, the sealing members 71 and 72 are heated and melted so as not to melt the third region R3 and the fourth region R4. Therefore, the third region R3 and the fourth region R4 remain unwelded even after step S103. Furthermore, in this embodiment, the thickness of the sealing member 71 in the Z-axis direction is greater than the thickness of the detection line 60 in the Z-axis direction. In step S103, the sealing member 71 is heated so that the difference between the height H1 of the sealing member 71 from the surface 15b in the first region R1 and the height H2 of the sealing member 71 from the surface 15b in the second region R2 is smaller than the thickness T of the detection line 60, as shown in FIG. 10B . As a result, the sealing member 71 after welding is flat compared to the protrusion (thickness T) of the detection line 60 from the surface 15b.

[0069] In the next step, as shown in FIGS. 4 and 11 , a second stage of bonding of the sealing members 71 and 72 is performed (step S104: second bonding step). That is, in step S104, the sealing members 71 and 72 are heated and melted (i.e., bonded) in the second region R2, which was not welded in step S103. Here, a heater Z4 is used, which extends from the first region R1 to the second region R2. In the example of FIG. 11( a), the heater Z4 located on the surface 15b side of the current collector 15 is thicker in a portion Z4b overlapping the first region R1 and the second region R2 as viewed from the Z-axis direction than in a portion Z4a overlapping the second region R2 as viewed from the Z-axis direction. This reduces the electrical resistance of the heater Z4 in the portion Z4b, thereby reducing the amount of heat generated, and thus the amount of heat input to the first region R1 is relatively reduced.

[0070] In other words, in step S104, the first region R1 and the second region R2 are simultaneously heated and melted (i.e., bonded) to the seal member 71 so that the heat input to the second region R2 is greater than the heat input to the first region R1. The heat input from the heater Z4 to the first region R1 may be set, for example, so that the temperature of the first region R1 does not exceed the melting point of the seal member 71. However, the portion Z4a of the heater Z4 that generates a relatively large amount of heat may be set to include the boundary between the first region R1 and the second region R2. In other words, the portion Z4a may be set to overlap the second region R2 with the first region R1, thereby remelting the boundary between the first region R1 and the second region R2.

[0071] 11(b), the heater Z4 has a uniform thickness from the first region R1 to the second region R2, but a recess Z2a that overlaps the first region R1 and the second region R2 as viewed from the Z-axis direction is formed in the elastic member Z2 on the surface 15b side of the current collector 15. As a result, when the heater Z4 is pressed against the sealing member 71 from the surface 15b side by the pressing force from the jig Z1, the surface pressure applied to the first region R1 is smaller than the surface pressure applied to the second region R2. As a result, the amount of heat input to the first region R1 is relatively small.

[0072] 11B, in step S104, the sealing member 71 is welded so that the amount of heat input to the second region R2 is greater than the amount of heat input to the first region R1. In this case, the recess Z2a may be set to remain inside the first region R1 rather than the boundary between the first region R1 and the second region R2. In this case, sufficient surface pressure is also applied to the boundary portion between the first region R1 and the second region R2, causing the boundary portion to re-melt.

[0073] In steps S103 and S104, the sealing members 71 and 72 are welded to each other in the fourth region R4, thereby partially integrating the sealing members 71 and 72. At this time, the sealing members 71 and 72 are not welded to each other in the third region R3, thereby preventing the sealing members 71 and 72 from being welded to each other.

[0074] As a result, welding of the seal members 71 and 72 is completed at the first side portion 151 (and the corresponding portion of the surface 15a) on which the detection lines 60 are provided on the surface 15b of the current collector 15. Thereafter, the seal members 71 and 72 are bonded to the three second side portions 152 (and the corresponding portions of the surface 15a) on which the detection lines 60 are not provided on the surface 15b of the current collector 15 (third bonding step). In the above-described step S104, when bonding the seal member 71 at the first side portion 151 of the four side portions, a larger surface pressure is applied to the seal member 71 than in the third bonding step (i.e., compared to when welding the seal member 71 at the second side portion 152). As a result, the frame-shaped seal members 71 and 72 are entirely welded to the current collector 15, and the seal member 41 is formed from the seal members 71 and 72, and the third electrode unit U3 including the seal member 41 is configured.

[0075] 4 , the plurality of third electrode units U3 configured as described above are stacked along the Z-axis direction with separators 14 and spacers 42 interposed therebetween (step S105: stacking step), and the plurality of sealing members 41 (of the plurality of third electrode units U3) stacked on top of each other are integrated to form the electrode stack 10 and the sealing body 20 (step S106: integration step). In step S106, the third region R3 (i.e., the outer edge 71 e of the outer portion 71 b) and the plurality of spacers 42 that were left unwelded in steps S103 and S104 are welded to each other to form the welded portion 43, thereby forming the sealing body 20.

[0076] Thereafter, subsequent processes such as a process of forming a liquid injection port 50 in the sealing body 20 and a process of injecting the electrolyte into the internal space S using the liquid injection port 50 are carried out, and the energy storage module 1 is manufactured.

[0077] As described above, in the energy storage module manufacturing method according to this embodiment, first, the detection wire 60 is joined to the surface 15b of the current collector 15 of the electrode (step S101). At this time, the detection wire 60 is joined to the surface 15b so that the detection wire 60 is drawn out of the current collector 15 when viewed from the Z-axis direction intersecting the surface 15b. Next, a sealing member 71, which is the sealing member 41, is placed on the surface 15b and the detection wire 60 (step S102). At this time, the sealing member 71 is placed so that, when viewed from the Z-axis direction, the sealing member 71 includes an inner portion 71a that overlaps the current collector 15 and an outer portion 71b that does not overlap the current collector 15, and is in contact with the surface 15b and the detection wire 60. Furthermore, when viewed from the Z-axis direction, the inner portion 71a includes the detection wire 60, a first region R1 that overlaps the periphery of the detection wire 60, and a second region R2 that is continuous with the first region R1. Next, the sealing member 71 is heated and melted to bond the sealing member 71 to the surface 15b and the detection line 60 (steps S103 and S104). In this step, first, in a first region R1 overlapping the detection line 60 and the periphery thereof, the sealing member 71 is bonded to the detection line 60, and the sealing member 71 is bonded to the surface 15b around the detection line 60 (step S103). Then, in a second region R2 continuous with the first region R1, the sealing member 71 is bonded to the surface 15b (step S104). In this way, when bonding the sealing member 71 to the electrode to which the detection line 60 is bonded, the detection line 60 and the first region R1 around the detection line 60 are melted and bonded before the second region R2, thereby suppressing the occurrence of a gap between the current collector 15 and the sealing member 71 in the region around the detection line 60.

[0078] Furthermore, in the energy storage module manufacturing method according to this embodiment, the first region R1 is composed of an overlapping region Ra that overlaps with the detection line 60 as viewed from the Z-axis direction and a non-overlapping region Rb that does not overlap with the detection line 60 as viewed from the Z-axis direction. The non-overlapping region Rb includes, when viewed from the Y-axis direction intersecting the Z-axis direction, a region between the overlapping region Ra and each of contact points CP at which the sealing member 71 extends from both ends of the overlapping region Ra on the detection line 60 toward the surface 15b and contacts the surface 15b. Then, in step S103, the sealing member 71 is joined to the detection line 60 in the overlapping region Ra, and the sealing member 71 is joined to the surface 15b in the non-overlapping region Rb. This reliably prevents a gap from being generated between the current collector 15 and the sealing member 71 in the region around the detection line 60 (the non-overlapping region Rb).

[0079] In the energy storage module manufacturing method according to this embodiment, the thickness of the sealing member 71 in the Z-axis direction is greater than the thickness of the detection line 60 in the Z-axis direction, and in step S103, the sealing member 71 is heated so that the difference in the Z-axis direction between the height H1 of the sealing member 71 from the surface 15b in the first region R1 and the height H2 of the sealing member 71 from the surface 15b in the second region R2 is smaller than the thickness T of the detection line 60. In this way, if the sealing member 71 is made relatively flat in step S103, it becomes easier to simultaneously heat the first region R1 and the second region R2 in step S104.

[0080] In the energy storage module manufacturing method according to this embodiment, in step S102, sealing member 72, which is sealing member 41, is arranged so as to overlap inner portion 71a when viewed from the Z-axis direction and so as to be in contact with surface 15a opposite surface 15b of current collector 15, and in step S104, heaters Z4 are pressed against each of sealing member 71 and sealing member 72 from both surfaces 15a and 15b. This allows sealing member 71 and sealing member 72 to be reliably welded from both surfaces 15a and 15b.

[0081] In the energy storage module manufacturing method according to this embodiment, in steps S103 and S104, the outer portion 71b includes a third region R3 including an outer edge 71e of the seal member 71 located opposite the inner portion 71a when viewed from the Z-axis direction, and a fourth region R4 located between the third region R3 and the inner portion 71a when viewed from the Z-axis direction, and in step S103, the seal member 71 is joined so as not to melt the third region R3. This makes it possible to ensure a welding allowance when integrating the multiple seal members 41 (formed by welding the seal members 71 and 72) together.

[0082] In the energy storage module manufacturing method according to this embodiment, in step S102, a seal member 72, which is the seal member 41, is arranged so that it overlaps the inner portion 71a and the fourth region R4 when viewed from the Z axis direction in steps S103 and S104, and so that it contacts the surface 15a opposite to the surface 15b. Then, in steps S103 and S104, the seal member 71 and the seal member 72 are welded together in the fourth region R4. This allows the seal member 71 and the seal member 72 to be welded together in the fourth region R4, while leaving the third region R3, including the outer edge 71e of the seal member 71, unwelded.

[0083] The energy storage module manufacturing method according to this embodiment further includes, after steps S103 and S104, steps S105 and S106 of stacking a plurality of third electrode units U3, each composed of an electrode and a sealing member 41 joined to the electrode, along the Z-axis direction and integrating the sealing members 41 of the plurality of stacked third electrode units U3, thereby forming the electrode stack 10 and the sealing body 20. This makes it possible to easily form the electrode stack 10 and the sealing body 20.

[0084] In the energy storage module manufacturing method according to this embodiment, in step S106, the outer edges (third regions R3) of the seal members 41 of the plurality of stacked third electrode units U3 as viewed in the Z-axis direction are welded to each other, thereby integrating the seal members 41 of the plurality of third electrode units U3. This makes it possible to reliably seal the internal space S.

[0085] In the energy storage module manufacturing method according to this embodiment, in step S106, the sealing member 71 is joined so that the amount of heat input to the second region R2 is greater than the amount of heat input to the first region R1. This makes it possible to join the sealing member 71 over the entire first side portion 151 while suppressing re-melting of the first region R1.

[0086] In the energy storage module manufacturing method according to this embodiment, the surface 15b has a rectangular shape including four sides. The energy storage module manufacturing method according to this embodiment also includes a third joining step in which the seal member 71 is joined to a second side portion 152 of the four sides other than the first side portion 151 to which the detection line 60 is joined. In step S104, when joining the seal member 71 to the first side portion 151, a greater surface pressure may be applied to the seal member 71 compared to the third joining step (i.e., compared to when joining the seal member 71 to the second side portion 152 of the four sides of the surface 15b other than the first side portion 151). In this case, it is possible to prevent wrinkles from forming in the seal member 71 at the first side portion 151.

[0087] Furthermore, in the energy storage module manufacturing method according to this embodiment, in steps S103 and S104, the heater Z4 is pressed against the sealing members 71 and 72 via the glass cloth Z5, thereby welding the sealing members 71 and 72. This makes it possible to prevent the sealing members 71 and 72 from welding to the heater Z4.

[0088] The above embodiment has described one aspect of the energy storage module manufacturing method according to the present invention. Therefore, the energy storage module manufacturing method according to the present invention is not limited to the above embodiment and can be modified as desired.

[0089] For example, in the above embodiment, the amount of heat input to the first region R1 is relatively reduced by reducing the resistance of the portion of the heater Z4 corresponding to the first region R1 or by forming a recess Z2a in the portion of the elastic member Z2 corresponding to the first region R1 in step S104. However, in step S104, the entire first region R1 and the entire second region R2 may be heated and melted by using a heater Z4 that is uniform from the first region R1 to the second region R2.

[0090] Furthermore, in the above embodiment, the case has been described in which the sealing members 71 and 72 are respectively disposed on the surfaces 15a and 15b of the current collector 15, and the sealing members 71 and 72 are collectively welded to the current collector 15. However, the above steps S102 to S104 can be applied to a case in which the sealing member 71 is provided at least on the surface 15b side of the current collector 15 to which the detection wire 60 is joined.

[0091] The following additional notes are provided regarding the above embodiment.

[0092] The energy storage module manufacturing method according to the appendix is ​​[1] "a method for manufacturing an energy storage module including: an electrode stack including a plurality of electrodes stacked along a first direction; a sealing body provided on the electrode stack so as to surround the electrode stack by stacking sealing members provided on each of the plurality of electrodes along the first direction, the sealing body being configured to seal a plurality of internal spaces formed between the electrodes adjacent in the first direction; and a plurality of terminals joined to each of the plurality of electrodes and drawn out to the sealing body, the method comprising: a terminal joining step of joining the terminals to first surfaces of the electrodes at peripheral portions of the electrodes; a seal arranging step of arranging first seal members that are the sealing members on the first surfaces and the terminals at the peripheral portions; and a seal joining step of joining the first seal member to the first surfaces and the terminals by heating and melting the first seal member." and a step of: joining the terminal to the first surface such that the terminal is drawn out of the electrode when viewed from a second direction intersecting the first surface; and placing the first seal member such that, when viewed from the second direction, the first seal member includes an inner portion that overlaps the electrode and an outer portion that does not overlap the electrode, and the inner portion includes, when viewed from the second direction, the terminal and the first surface around the terminal, a first region that overlaps the terminal and the first surface around the terminal, and a second region that is continuous with the first region and overlaps the first surface; and the seal joining step includes: a first joining step of joining the first seal member to the terminal and joining the first seal member to the first surface around the terminal in the first region; and a second joining step of joining the first seal member to the first surface in the second region after the first joining step.

[0093] The energy storage module manufacturing method according to the appendix may be [2] "the energy storage module manufacturing method described in [1] above, in which in the second joining step, the sealing member is heated simultaneously to the first region and the second region, and the heat input to the second region is greater than the heat input to the first region, thereby joining the sealing member."

[0094] The storage module manufacturing method according to the appendix may be [3] "the storage module manufacturing method described in [1] or [2] above, wherein the thickness of the sealing member in the second direction is greater than the thickness of the terminal in the second direction, and in the first joining step, the first sealing member is heated so that the difference in the second direction between the height of the first sealing member from the first surface in the first region and the height of the first sealing member from the first surface in the second region is smaller than the thickness of the terminal."

[0095] The manufacturing method of the storage module according to the appendix may be [4] "the manufacturing method of the storage module according to any one of the above [1] to [3], wherein in the seal arrangement step, a second seal member is arranged so as to overlap the inner portion when viewed from the second direction and to be in contact with a second surface of the electrode opposite to the first surface, and in the first joining step, heaters are pressed against each of the first seal member and the second seal member from both the first surface and the second surface."

[0096] The storage module manufacturing method according to the appendix may be [5] "the storage module manufacturing method according to any one of [1] to [4] above, wherein in the seal joining step, the outer portion includes a third region that includes an outer edge of the first seal member when viewed from the second direction, and a rectangular frame-shaped fourth region that is located between the third region and the inner portion when viewed from the second direction, and in the first joining step, the first seal member is joined so as not to melt the third region."

[0097] The storage module manufacturing method according to the appendix may be [6] "the storage module manufacturing method described in [5] above, wherein in the seal positioning step, a second seal member is positioned so as to overlap the inner portion and the fourth region when viewed from the second direction in the seal joining step and to be in contact with a second surface of the electrode opposite the first surface, and in the first joining step, the first seal member and the second seal member are welded together in the fourth region."

[0098] The energy storage module manufacturing method according to the appendix may be [7] "the energy storage module manufacturing method according to any one of the above [1] to [6], further comprising: after the seal joining step, stacking a plurality of units, each of which is formed by the electrode and the sealing member joined to the electrode, along the first direction, and integrating the sealing members of the plurality of units stacked on top of each other to form the electrode stack and the sealing body."

[0099] The storage module manufacturing method according to the appendix may be [8] "the storage module manufacturing method described in [7] above, in which in the integration process, the outer edges of the sealing members of the multiple units stacked on top of each other when viewed from the first direction are welded to each other, thereby integrating the sealing members of the multiple units."

[0100] The energy storage module manufacturing method according to the appendix may be [9] "the energy storage module manufacturing method according to any one of [1] to [8] above, wherein the first surface has a rectangular shape including four side portions, and the seal joining step includes a third joining step of joining the seal member at a second side portion of the four side portions of the first surface other than the first side portion to which the terminal is joined, and in the second joining step, when joining the seal member at the first side portion of the four side portions of the first surface, a surface pressure applied to the seal member is greater than that in the third joining step."

[0101] The storage module manufacturing method according to the appendix may be

[10] "the storage module manufacturing method according to any one of the above [1] to [9], wherein in the seal joining step, the sealing member is heated by pressing a heater against the sealing member via a glass cloth."

[0102] The energy storage module manufacturing method according to the appendix may be

[11] "the energy storage module manufacturing method according to any one of [1] to

[10] above, wherein the first region is composed of an overlapping region that overlaps with the terminal when viewed from the second direction and a non-overlapping region that does not overlap with the terminal when viewed from the second direction, and the non-overlapping region includes, when viewed from a direction intersecting the second direction, a region between the overlapping region and each of contact points where the first sealing member extends from both ends of the overlapping region on the terminal toward the first surface and contacts the first surface, and in the first joining step, the first sealing member is joined to the terminal in the overlapping region and the first surface in the non-overlapping region."

[0103] REFERENCE SIGNS LIST 1 Energy storage module 10 Electrode stack 20 Sealing body 41 Sealing member 60 Detection line (terminal) 71 Sealing member (first sealing member) 71a Inner portion 71b Outer portion 71e Outer edge 72 Sealing member (second sealing member) R1 First region R2 Second region R3 Third region R4 Fourth region Z4 Heater

Claims

1. A method for manufacturing an energy storage module comprising: an electrode stack including a plurality of electrodes stacked along a first direction; a sealing body provided on the electrode stack so as to surround the electrode stack by stacking sealing members provided on each of the plurality of electrodes along the first direction, the sealing body being for sealing a plurality of internal spaces formed between the electrodes adjacent in the first direction; and a plurality of terminals joined to each of the plurality of electrodes and drawn out to the outside of the sealing body, the method comprising: a terminal joining step of joining the terminals to first surfaces of the electrodes at peripheral edges of the electrodes; a seal arranging step of arranging first sealing members as the sealing members on the first surfaces and the terminals at the peripheral edges; and a seal joining step of joining the first sealing members to the first surfaces and the terminals by heating and melting the first sealing members; wherein in the terminal joining step, the terminals are joined to the first surfaces such that the terminals are drawn out to the outside of the electrodes when viewed from a second direction intersecting the first surfaces, the seal positioning step positions the first seal member such that, when viewed from the second direction, the first seal member includes an inner portion that overlaps the electrode and an outer portion that does not overlap the electrode, and the inner portion includes, when viewed from the second direction, a first region that overlaps the terminal and the first surface around the terminal, and a second region that is continuous with the first region and overlaps the first surface, and the seal joining step includes: a first joining step of joining the first seal member to the terminal in the first region and joining the first seal member to the first surface around the terminal, and a second joining step of joining the first seal member to the first surface in the second region after the first joining step.

2. The energy storage module manufacturing method according to claim 1, wherein in the second joining step, the sealing member is heated simultaneously in the first region and the second region so that the heat input to the second region is greater than the heat input to the first region, thereby joining the sealing member.

3. The method for manufacturing an energy storage module according to claim 1, wherein the thickness of the sealing member in the second direction is greater than the thickness of the terminal in the second direction, and in the first joining step, the first sealing member is heated so that the difference in height from the first surface of the first sealing member in the first region and the height from the first surface of the first sealing member in the second region in the second direction is smaller than the thickness of the terminal.

4. The method for manufacturing a storage module according to claim 1, wherein in the seal placement step, a second seal member is placed so as to overlap the inner portion when viewed from the second direction and to contact a second surface of the electrode opposite the first surface, and in the first joining step, heaters are pressed against each of the first seal member and the second seal member from both the first surface and the second surface.

5. The method for manufacturing an energy storage module according to claim 1, wherein in the seal joining step, the outer portion includes a third region that includes the outer edge of the first seal member when viewed from the second direction, and a rectangular frame-shaped fourth region that is located between the third region and the inner portion when viewed from the second direction, and in the first joining step, the first seal member is joined so as not to melt the third region.

6. The method for manufacturing a storage module according to claim 5, wherein in the seal placement step, a second seal member is placed so as to overlap the inner portion and the fourth region when viewed from the second direction in the seal joining step and to contact a second surface of the electrode opposite the first surface, and in the first joining step, the first seal member and the second seal member are welded together in the fourth region.

7. The method for manufacturing a storage module according to claim 1, further comprising, after the seal joining step, an integration step of stacking a plurality of units each made up of the electrode and the sealing member joined to the electrode along the first direction and integrating the sealing members of the plurality of stacked units to form the electrode stack and the sealing body.

8. The method for manufacturing an energy storage module according to claim 7, wherein in the integration step, the sealing members of the multiple units stacked on top of each other are integrated with each other by welding together outer edges of the sealing members of the multiple units when viewed from the first direction.

9. The method for manufacturing an energy storage module according to claim 1, wherein the first surface has a rectangular shape including four side portions, the seal joining process includes a third joining process in which the seal member is joined to a second side portion of the four side portions of the first surface other than the first side portion to which the terminal is joined, and in the second joining process, when joining the seal member to the first side portion of the four side portions of the first surface, a greater surface pressure is applied to the seal member than in the third joining process.

10. The method for manufacturing an electric storage module according to claim 1, wherein in the seal joining step, the seal member is heated by pressing a heater against the seal member via a glass cloth.

11. The method for manufacturing an energy storage module according to any one of claims 1 to 10, wherein the first region is composed of an overlapping region that overlaps with the terminal when viewed from the second direction, and a non-overlapping region that does not overlap with the terminal when viewed from the second direction, and the non-overlapping region includes, when viewed from a direction intersecting the second direction, a region between the overlapping region and each of the contact points where the first sealing member extends from both ends of the overlapping region on the terminal toward the first surface and makes contact with the first surface, and wherein in the first joining step, the first sealing member is joined to the terminal in the overlapping region and the first surface in the non-overlapping region.

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