Method for manufacturing power storage module and apparatus for manufacturing power storage module

Abstract

To provide a method and an apparatus for manufacturing a power storage module that can reliably seal the side surfaces of a laminate.SOLUTION: A method for manufacturing a power storage module 1 includes a restraining step S4 of applying a load to a laminate 10A, and a sealing step S5 of sealing the side surface of the laminate 10A. In the restraining step S4, the laminate 10A is restrained by a first restraining plate 71 and a second restraining plate 72 in a state where the distance between the first restraining plate 71 and the second restraining plate 72 corresponding to a non-overlapping region R2 of a seal member 412 that does not overlap with a detection line 60 is smaller than the distance between the first restraining plate 71 and the second restraining plate 72 corresponding to an overlapping region R1 of the seal member 412 that overlaps with the detection line 60. In the sealing step S5, while maintaining the restrained state of the restraining step S4, the outer peripheral portions of each seal member 412, each seal member 411, and each spacer 421 are heated so as to melt.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a power storage module and an apparatus for manufacturing a power storage module.

Background Art

[0002] A power storage module having a plurality of electrodes is known (see, for example, Patent Document 1). Each electrode has a current collector, an active material layer formed on the surface of the current collector, and a seal member provided on the surface of the current collector so as to surround the active material layer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When manufacturing the above-described power storage module, after a laminate is formed by laminating a plurality of electrodes, the seal members of the plurality of electrodes are melted while the laminate is constrained by a pair of restraint members disposed on both sides of the laminate in the lamination direction, so that the side surface of the laminate may be sealed. However, when, for example, a detection line or the like is provided on the surface of the current collector, the thickness of the region of the laminate where the detection line is provided is different from the thickness of the region of the laminate where the detection line is not provided. As a result, it becomes difficult for the load from the pair of restraint members to be applied to the region of the laminate close to the detection line. As a result, the quality of the sealing of the side surface of the laminate may deteriorate.

[0005] An object of the present invention is to provide a method for manufacturing a power storage module and an apparatus for manufacturing a power storage module that can reliably seal the side surface of a laminate.

Means for Solving the Problems

[0006] The method for manufacturing the power storage module of the present invention includes a stacking step of forming a stacked body by stacking a plurality of electrodes along the stacking direction, a constraining step of applying a load to the stacked body by a first constraining plate disposed on one side of the stacked body in the stacking direction and a second constraining plate disposed on the other side of the stacked body in the stacking direction, and a sealing step of sealing the side surface of the stacked body. Each of the plurality of electrodes has a current collector, an active material layer provided on the surface of the current collector, a seal member provided on the surface of the current collector so as to surround the active material layer when viewed from the stacking direction, and a detection line electrically connected to the surface of the current collector. The detection lines of the plurality of electrodes extend outside the outer edge of the seal member along a first direction so as to overlap the seal member when viewed from the stacking direction and are arranged along a second direction intersecting the first direction. The seal members of the plurality of electrodes include an overlapping region that overlaps the detection line when viewed from the stacking direction and a non-overlapping region located between the overlapping regions adjacent to each other when viewed from the stacking direction. In the constraining step, the stacked body is constrained by the first constraining plate and the second constraining plate in a state where the distance between the first constraining plate and the second constraining plate corresponding to the non-overlapping region is smaller than the distance between the first constraining plate and the second constraining plate corresponding to the overlapping region. In the sealing step, the seal member is heated so that the seal members of the plurality of electrodes melt while the constraining state in the constraining step is maintained.

[0007] In the constraining step of this method for manufacturing the power storage module, the stacked body is constrained by the first constraining plate and the second constraining plate in a state where the distance between the first constraining plate and the second constraining plate corresponding to the non-overlapping region is smaller than the distance between the first constraining plate and the second constraining plate corresponding to the overlapping region. As a result, a load is also applied to the region of the stacked body close to the detection line (that is, the region corresponding to the non-overlapping region of the stacked body), so that the members adjacent to each other come into contact. Moreover, in the sealing step, the seal member is heated so that the seal members of the plurality of electrodes melt while the constraining state in the constraining step is maintained. As a result, since the seal member melts while the above contact state is maintained, the quality of the sealing of the side surface of the stacked body is improved. Therefore, according to this method for manufacturing the power storage module, the side surface of the stacked body can be reliably sealed.

[0008] Of the first restraining plate, the first restraining surface facing the laminate includes a first region facing the overlapping region and a second region facing the non-overlapping region. In the restraining step, the laminate may be restrained by the first restraining plate and the second restraining plate with the second region in contact with the laminate and the first region separated from the laminate.

[0009] In the sealing step, the seal members of the plurality of electrodes may be heated by a non-contact heater.

[0010] The manufacturing apparatus for a power storage module of the present invention includes a first restraining plate disposed on one side in the stacking direction with respect to a laminate having a plurality of electrodes stacked along the stacking direction and applying a load to the laminate, a second restraining plate disposed on the other side in the stacking direction with respect to the laminate and applying a load to the laminate, and a non-contact heater for heating the side surface of the laminate. Each of the plurality of electrodes has a current collector, an active material layer provided on the surface of the current collector, a seal member provided on the surface so as to surround the active material layer when viewed from the stacking direction, and a detection line electrically connected to the surface of the current collector. The detection lines of the plurality of electrodes extend outside the outer edge of the seal member along a first direction so as to overlap the seal member when viewed from the stacking direction and are arranged along a second direction intersecting the first direction. The seal members of the plurality of electrodes include an overlapping region overlapping the detection line when viewed from the stacking direction and a non-overlapping region located between adjacent overlapping regions when viewed from the stacking direction. The first restraining surface of the first restraining plate facing the laminate includes a first region facing the overlapping region and a second region facing the non-overlapping region. The distance between the second region and the second restraining plate is smaller than the distance between the first region and the second restraining plate.

[0011] In the manufacturing apparatus of this power storage module, the first restraint surface of the first restraint plate includes a first region facing the overlapping region and a second region facing the non-overlapping region, and the distance between the second region and the second restraint plate is smaller than the distance between the first region and the second restraint plate. As a result, a load is also applied to the region of the laminate close to the detection line (i.e., the region corresponding to the non-overlapping region of the laminate), so that the members adjacent to each other come into contact. Moreover, the heater heats the seal member so that the seal members of the plurality of electrodes melt while the above-described restraint state is maintained. As a result, the seal member melts while the above contact state is maintained, so that the quality of the sealing of the side surface of the laminate is improved. Therefore, according to the manufacturing apparatus of this power storage module, the side surface of the laminate can be reliably sealed.

[0012] The second region may protrude more than the first region.

Advantages of the Invention

[0013] According to the present invention, it is possible to provide a method for manufacturing a power storage module and a manufacturing apparatus for a power storage module that can reliably seal the side surface of a laminate.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant descriptions are omitted.

[0016] The power storage module 1 shown in FIG. 1 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 be, for example, an electric double layer capacitor. In the present embodiment, the power storage module 1 is a lithium-ion secondary battery.

[0017] As shown in FIGS. 1 and 2, the power storage module 1 includes an electrode laminate 10, a sealing body 20, a sealing member 30, and a plurality of detection lines 60. The electrode laminate 10 includes a plurality of electrodes laminated along the Z-axis direction. The electrode laminate 10 has, for example, a rectangular parallelepiped shape.

[0018] The sealing body 20 has a sealing main body 40 and a liquid injection port portion 50. The sealing main body 40 is provided at the peripheral edge of the electrode laminate 10. The sealing main body 40 seals the side surface of the electrode laminate 10. The sealing main body 40 has, for example, a rectangular tubular shape. The sealing main body 40 has electrical insulation properties.

[0019] The liquid injection port portion 50 is provided in a region of the sealing main body 40 where a liquid injection port 20a (described later) is formed. The liquid injection port portion 50 is provided on the side surface 40c of the sealing main body 40. The width of the liquid injection port portion 50 in the X-axis direction is smaller than the width of the sealing main body 40 in the X-axis direction. Both ends of the liquid injection port portion 50 in the X-axis direction are located inside both ends of the sealing main body 40 in the X-axis direction. The liquid injection port portion 50 includes a side wall portion 51, an overhang portion 52, an overhang portion 53, a frame portion 54, and a thin wall portion 55.

[0020] The side wall portion 51 is provided on the side surface 40c of the sealing main body 40. The side wall portion 51 has, for example, a rectangular plate shape. The overhang portion 52 is provided on one end surface of the sealing main body 40 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 main body 40 in the Z-axis direction. The overhang portion 53 has, for example, a rectangular plate shape.

[0021] The liquid injection port portion 50 includes a plurality of frame portions 54. The frame portion 54 protrudes from the side surface of the side wall portion 51. The frame portion 54 surrounds each liquid injection port 20a arranged in the Z-axis direction when viewed from the Y-axis direction (the first direction). The thin wall portion 55 is provided on the side surfaces of the side wall portion 51 on both sides in the X-axis direction with respect to the side wall portion 51. The thin wall portion 55 extends along the Z-axis direction. The thin wall portion 55 reaches both ends of the side wall portion 51 in the Z-axis direction. The thickness of the thin wall portion 55 is smaller than the thickness of the side wall portion 51. Each of the side wall portion 51, the overhang portions 52 and 53, the frame portion 54, and the thin wall portion 55 is a part of the region of the liquid injection port portion 50 integrated by the same material. The liquid injection port portion 50 is formed, for example, by injection molding.

[0022] The sealing body 20 includes a plurality of liquid injection ports 20a. The liquid injection ports 20a communicate with the internal space S (see FIG. 3) of the electrode laminate 10. The liquid injection ports 20a function as paths for injecting the electrolytic solution into the internal space S. The sealing body 20 has a plurality of rows of liquid injection ports. The plurality of rows of liquid injection ports are arranged in the Z-axis direction. Each row of liquid injection ports includes a plurality of liquid injection ports 20a arranged in the X-axis direction. Each row of liquid injection ports includes, for example, 10 liquid injection ports 20a. When viewed from the Y-axis direction, in each row of liquid injection ports, the plurality of liquid injection ports 20a are arranged obliquely with respect to the X-axis direction. In each row of liquid injection ports, the liquid injection ports 20a are separated from each other in the X-axis direction.

[0023] The sealing member 30 has, for example, a plate shape. The sealing member 30 overlaps with a plurality of frame portions 54 when viewed from the X-axis direction. 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 or the like. The sealing member 30 is welded to the tips of the plurality of frame portions 54. Thereby, the plurality of liquid injection ports 20a are sealed. In FIG. 2, the illustration of the sealing member 30 is omitted.

[0024] The plurality of detection lines 60 are located adjacent to the plurality of frame portions 54 when viewed from the Y-axis direction. The detection lines 60 are used for detecting the battery state of the power storage module 1. In the present embodiment, the voltage between the electrodes adjacent to each other in the power storage module 1 is detected by an external device via the detection lines 60. That is, the detection lines 60 are, for example, voltage detection lines. The detection lines 60 protrude from the side wall portion 51. Each detection line 60 is electrically connected to each current collector 15 described later.

[0025] The storage module 1 has a plurality of detection line arrays 61. The detection line array 61 has a plurality of detection lines 60 arranged in the Z-axis direction. That is, the plurality of detection lines 60 constituting one detection line array 61 overlap each other when viewed from the Z-axis direction. The plurality of detection line arrays 61 are arranged along the X-axis direction at predetermined intervals. The positions of the respective detection lines 60 in the Z-axis direction are shifted from each other. In the present embodiment, each detection line array 61 is located on the negative terminal electrode 13 side (the lower side in FIG. 2) described later toward the side opposite to the frame portion 54 in the X-axis direction. 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 on the positive terminal electrode 12 side (the upper side in FIG. 2) described later than the other detection line 60 of the other detection line array 61 located on the side opposite to the frame portion 54 with respect to the one detection line array 61. Note that the one detection line 60 is the Nth (N is a natural number) detection line counted from the positive terminal electrode 12 side among the one detection line array 61, and the other detection line 60 is the Nth (N is a natural number) detection line counted from the positive terminal electrode 12 side among the other detection line array 61.

[0026] As shown in FIG. 3, the electrode laminate 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 electrode 12, the negative terminal electrode 13, and the plurality of separators 14 are laminated along the Z-axis direction (lamination direction).

[0027] The bipolar electrode 11 has a current collector 15, a first active material layer 16, and a second active material layer 17. The current collector 15, when viewed from the Z-axis direction, exhibits, for example, a rectangular shape. The current collector 15 includes a surface 15a and a surface 15b on the side opposite to the surface 15a.

[0028] 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. The first active material layer 16 has, for example, a rectangular shape when viewed in the Z-axis direction. The surface 15a includes an uncoated region where the first active material layer 16 is not provided. The uncoated region surrounds the first active material layer 16 when viewed in the Z-axis direction.

[0029] 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. The second active material layer 17 has, for example, a rectangular shape when viewed in the Z-axis direction. The surface 15b includes an uncoated region where the second active material layer 17 is not provided. The uncoated region surrounds the second active material layer 17 when viewed in the Z-axis direction. When viewed in 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 in 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.

[0030] The plurality of 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. That is, the plurality of bipolar electrodes 11 are stacked such that, among 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.

[0031] The positive terminal electrode 12 is disposed on one side in the Z-axis direction with respect to the plurality of bipolar electrodes 11. The positive terminal electrode 12 has a current collector 15 and a first active material layer 16. The positive terminal electrode 12 is mainly different from the bipolar electrode 11 in that it does not have a second active material layer 17. Other configurations of the positive terminal electrode 12 may be the same as those 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 laminated 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.

[0032] The negative terminal electrode 13 is disposed on the other side in the Z-axis direction with respect to the plurality of bipolar electrodes 11. The negative terminal electrode 13 has a current collector 15 and a second active material layer 17. The negative terminal electrode 13 is mainly different from the bipolar electrode 11 in that it does not have a first active material layer 16. Other configurations of the negative terminal electrode 13 may be the same as those of the bipolar electrode 11. The second active material layer 17 of the negative terminal electrode 13 faces the first active material layer 16 of the bipolar electrode 11. That is, the negative terminal electrode 13 is laminated such that the surface 15b of the current collector 15 of the negative terminal electrode 13 faces the surface 15a of the current collector 15 of the bipolar electrode 11 adjacent to the negative terminal electrode 13.

[0033] The outer edges of the current collectors 15 of the respective electrodes 11, 12, 13 constitute the side surface of the electrode laminate 10. An internal space S for accommodating an electrolytic solution is formed between the respective bipolar electrodes 11, between the bipolar electrode 11 and the positive terminal electrode 12, and between the bipolar electrode 11 and the negative terminal electrode 13.

[0034] Separator 14 is 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 separator 14 is provided between the first active material layer 16 and the second active material layer 17 facing each other. The separator 14, for example, exhibits a sheet shape. When viewed from the Z-axis direction, the outer edge of the separator 14 is located outside each of the outer edges of the first active material layer 16 and the second active material layer 17. The separator 14 allows charge carriers such as lithium ions to pass through. The separator 14 isolates the electrodes 11, 12, 13 adjacent to each other. Thereby, an electrical short circuit due to contact of the electrodes 11, 12, 13 is prevented. The separator 14 absorbs and holds the electrolytic solution.

[0035] The current collector 15 has a function of maintaining the flow of current in the first active material layer 16 and the second active material layer 17 during discharge or charging of the power storage module 1. The current collector 15 is, for example, a chemically inert electrical conductor. The material of the current collector 15 is, for example, a metal material, a conductive resin material, a conductive inorganic material, or the like. The conductive resin material is, for example, a conductive polymer material or a non-conductive polymer material added with a conductive filler. When the current collector 15 has a plurality of layers, the material of each layer may be any of the above-described materials. 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.

[0036] The current collector 15 exhibits, for example, a plate shape, foil shape, sheet shape, film shape, or mesh shape, etc. The current collector 15 may be, for example, aluminum foil, copper foil, nickel foil, titanium foil, or stainless steel foil, etc. The current collector 15 may be an alloy foil or clad foil of the above metals. When the current collector 15 is in foil form, 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 a plurality of 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, aluminum foil and copper plating formed on one side of the aluminum foil. The current collector 15 may include a plurality of metal foils adhered by a conductive adhesive.

[0037] The first active material layer 16 contains a positive electrode active material capable of occluding and releasing charge carriers such as lithium ions. The positive electrode active material is, for example, a composite oxide, lithium metal, or sulfur, etc. The composite oxide contains, for example, at least one of iron, manganese, titanium, nickel, cobalt, and aluminum, and lithium. The composite oxide is olivine-type lithium iron phosphate (LiFePO4), LiCoO2, LiNiMnCoO2, etc.

[0038] The second active material layer 17 contains a negative electrode active material capable of occluding and releasing charge carriers such as lithium ions. The negative electrode active material is, for example, graphite, artificial graphite, highly oriented graphite, mesocarbon microbeads, hard carbon, soft carbon, a metal compound, an element capable of alloying with lithium or a compound thereof, boron-added carbon, etc. The element capable of alloying with lithium is, for example, silicon or tin.

[0039] Each of the first active material layer 16 and the second active material layer 17 may contain, in addition to the active material, a binder and a conductive aid. The binder has a function of connecting the active material or the conductive aid to each other and maintaining the conductive network in the electrode. Examples of the binder 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 cross-linked products, starch-acrylic acid graft polymers, and the like. These binders can be used alone or in combination. The conductive aid is a conductive material and has a function of enhancing electrical conductivity. Examples of the conductive aid include acetylene black, carbon black, and graphite. The viscosity-adjusting solvent is, for example, N-methyl-2-pyrrolidone or the like.

[0040] For the formation of the first active material layer 16 on the surface 15a and the formation of the second active material layer 17 on the surface 15b, conventionally known methods such as a roll coating method, a die coating method, a dip coating method, a doctor blade method, a spray coating method, and a curtain coating method are used. Specifically, the active material, the solvent, and, if necessary, the binder and the conductive aid are mixed to produce a slurry-like composition for forming the active material layer, and after applying the composition for forming the active material layer to the surface 15a or the surface 15b, it is dried. Examples of the solvent include N-methyl-2-pyrrolidone, methanol, methyl isobutyl ketone, and water. In order to increase the electrode density, the dried product may be compressed.

[0041] The electrolyte is accommodated in the internal space S. The electrolyte has penetrated the separator 14. The electrolyte 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 is, for example, a known lithium salt such as LiClO4, LiAsF6, LiPF6, LiBF4, LiCF3SO3, LiN(FSO2)2, LiN(CF3SO2)2, etc. The non-aqueous solvent is cyclic carbonates, cyclic esters, chain carbonates, chain esters, ethers, etc. Note that two or more of these known solvent materials may be combined and used.

[0042] The sealing body 40 has a sealing member 41, a spacer 42, and a welding portion 43. The sealing member 41, for example, has a rectangular frame shape. The sealing member 41 covers the peripheral portions of the current collectors 15. The sealing member 41 is provided on the surfaces 15a and 15b of each current collector 15. The sealing member 41 surrounds 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 separated 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.

[0043] The spacer 42, for example, has 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 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 welding portion 43 is integrated by welding the outer edge portions of each sealing member 41 and each spacer 42. The welding portion 43, for example, has a rectangular cylindrical shape.

[0044] The materials of the seal member 41 and the spacer 42 are, for example, acid-modified polyethylene (acid-modified PE), acid-modified polypropylene (acid-modified PP), polyethylene, or polypropylene, etc. Each of the seal member 41 and the spacer 42 has electrolyte resistance. The materials of the seal member 41 and the spacer 42 may be the same or different from each other. In the present embodiment, the material of the seal member 41 is, for example, acid-modified polyethylene or acid-modified polypropylene. In the present embodiment, the material of the spacer 42 is, for example, polyethylene or polypropylene. Acid-modified polyethylene and acid-modified polypropylene are easier to bond to metal compared to non-acid-modified polyethylene and non-acid-modified polypropylene. When the current collector 15 is made of metal, by forming the seal member 41 of acid-modified polyethylene or acid-modified polypropylene, the bonding strength of the seal member 41 to the current collector 15 can be improved.

[0045] The detection line 60 is provided on the surface 15b of each current collector 15 and is electrically connected to the surface 15b. The detection line 60 is located between the surface 15b of the current collector 15 and the seal member 41. The detection line 60 penetrates through the sealing body 20 and extends to the outside of the sealing body 20. The detection line 60 is formed of, for example, metal. The detection line 60 is, for example, stainless steel foil or the like.

[0046] Next, a manufacturing apparatus for the power storage module 1 (hereinafter simply referred to as the "manufacturing apparatus") will be described. As shown in FIGS. 4 and 5, the manufacturing apparatus 70 includes a first restraint plate 71, a second restraint plate 72, and a heater 73. The first restraint plate 71 is disposed on one side in the Z-axis direction with respect to the laminate 10A described later. The first restraint plate 71 is a member for applying a load to the laminate 10A.

[0047] The first restraint plate 71 has, for example, a rectangular frame shape. Each of the inner edge 71b and the outer edge 71c of the first restraint plate 71 has a rectangular shape when viewed in the Z-axis direction. The first restraint plate 71 includes a first restraint surface 71a facing the laminate 10A. The first restraint surface 71a includes a plurality of first regions 71d and a plurality of second regions 71e. The first regions 71d and the second regions 71e are formed on one side portion of the rectangular frame-shaped first restraint plate 71.

[0048] The first region 71d is a groove formed in the first restraint surface 71a. That is, the first region 71d is recessed from the first restraint surface 71a. The first region 71d extends along the Y-axis direction and opens to each of the inner edge 71b and the outer edge 71c of the first restraint plate 71. The plurality of first regions 71d are arranged at equal intervals along the X-axis direction. The second region 71e is located between a pair of adjacent first regions 71d. The second region 71e is the region between the adjacent first regions 71d on the first restraint surface 71a. The second region 71e protrudes toward the laminate 10A more than the first region 71d. The first regions 71d and the second regions 71e are arranged alternately along the X-axis direction. In the present embodiment, a pair of first regions 71d are formed on both sides in the X-axis direction with respect to any second region 71e.

[0049] The second restraint plate 72 is disposed on the other side in the Z-axis direction with respect to the laminate 10A. The second restraint plate 72 is a member for applying a load to the laminate 10A. The second restraint plate 72 has, for example, a plate shape. The second restraint plate 72 includes a second restraint surface 72a facing the laminate 10A. The second restraint surface 72a is a flat surface intersecting the Z-axis direction. When viewed in the Z-axis direction, the outer edge 72c of the second restraint plate 72 coincides with the outer edge 71c of the first restraint plate 71. The first restraint plate 71 and the second restraint plate 72 apply a load to the laminate 10A with the laminate 10A sandwiched therebetween.

[0050] The heater 73 is a device for heating the side surface of the laminate 10A. The heater 73 applies heat to the laminate 10A while being separated from the laminate 19A. That is, the heater 73 is a non-contact type heating device. The heater 73 is, for example, a carbon filament heater or the like.

[0051] Next, a method for manufacturing the power storage module 1 using the manufacturing apparatus 70 (hereinafter simply referred to as the "manufacturing method") will be described. As shown in FIG. 6, the manufacturing method includes a detection line welding step S1, a seal member welding step S2, a lamination step S3, a restraint step S4, a sealing step S5, and an injection molding step S6.

[0052] First, the detection line welding step S1 is performed. As shown in FIG. 7, in the detection line welding step S1, the detection line 60 is provided on the surface 15b of the current collector 15 of the bipolar electrode 11. The detection line 60 extends along the Y-axis direction so as to protrude from the outer edge 15c of the current collector 15. The detection line 60 is fixed to the surface 15b, for example, by ultrasonic welding. The detection line 60 is electrically connected to the current collector 15. In the detection line welding step S1, the detection line 60 is also provided on the positive terminal electrode 12 and the negative terminal electrode 13.

[0053] Subsequently, the seal member welding step S2 is performed. As shown in FIG. 8, in the seal member welding step S2, the seal member 411 is disposed on the surface 15a of the current collector 15, and the seal member 412 is disposed on the surface 15b of the current collector 15. Each of the seal member 411 and the seal member 412 has a rectangular frame shape. The seal member 411 is provided on the surface 15a so as to surround the first active material layer 16, and the seal member 412 is provided on the surface 15b so as to surround the second active material layer 17.

[0054] Each of the seal members 411 and 412 protrudes from the outer edge 15c of the current collector 15. The seal member 412 overlaps the detection line 60 when viewed from the Z-axis direction. The detection line 60 is sandwiched between the current collector 15 and the seal member 412. Subsequently, the seal members 411 and 412 are heated while being sandwiched by a heater such as an impulse sealer. As a result, the portion of the seal member 411 that overlaps the surface 15a is welded to the surface 15a, and the portion of the seal member 412 that overlaps the surface 15b is welded to the surface 15b. As a result, the electrode 11A having the bipolar electrode 11, the seal member 411, and the seal member 412 is formed. In the seal member welding step S2, the end face of the region of the current collector 15 where the detection line 60 is provided may be covered by the melted seal member 411. Further, in the seal member welding step S2, the end faces of the regions of the current collector 15 where the detection line 60 is not provided may be covered by the seal member 411 and the seal member 412 welded to each other. Note that the outer edge portions of the seal member 411 and the seal member 412 may not be welded to each other.

[0055] As shown in FIG. 9, the detection line 60 extends outward from the outer edge of the seal member 412 along the Y-axis direction so as to overlap the seal member 412 when viewed from the Z-axis direction. In FIG. 9, the detection lines 60 provided on other current collectors 15 are also shown (the dashed-dotted line in FIG. 9). The positions where the detection lines 60 are provided in each current collector 15 are different from each other. The plurality of detection lines 60 are arranged along the X-axis direction (the second direction intersecting the first direction) when viewed from the Z-axis direction. The seal member 412 includes an inner peripheral portion 41a located inside the outer edge 15c of the current collector 15 and an outer peripheral portion 41b located outside the outer edge 15c of the current collector 15. The detection line 60 extends outside the current collector 15 so as to overlap the inner peripheral portion 41a and the outer peripheral portion 41b when viewed from the Z-axis direction.

[0056] The seal member 412 includes a superimposed region R1 that overlaps with the detection line 60 when viewed in the Z-axis direction, and a non-superimposed region R2 that does not overlap with the detection line 60 when viewed in the Z-axis direction. The non-superimposed region R2 is located between the superimposed regions R1 adjacent to each other when viewed in the Z-axis direction. The superimposed region R1 includes an inner region R11 and an outer region R12. The inner region R11 is a region of the inner peripheral portion 41a of the seal member 412 that overlaps with the detection line 60. The outer region R12 is a region of the outer peripheral portion 41b of the seal member 412 that overlaps with the detection line 60. The non-superimposed region R2 includes an inner region R21 and an outer region R22. The inner region R21 is a region of the inner peripheral portion 41a of the seal member 412 that does not overlap with the detection line 60. The outer region R22 is a region of the outer peripheral portion 41b of the seal member 412 that does not overlap with the detection line 60. In the seal member welding step S2, the outer region R12 of the seal member 412 may be welded to the outer peripheral portion of the seal member 411 in a state where the detection line 60 is sandwiched between the outer region R12 and the outer peripheral portion of the seal member 411.

[0057] In the seal member welding step S2, the seal members 411 and 412 are also welded to the positive terminal electrode 12, thereby forming the electrode 12A (see FIG. 10). In the seal member welding step S2, the seal members 411 and 412 are also welded to the negative terminal electrode 13, thereby forming the electrode 13A (see FIG. 10).

[0058] Subsequently, a lamination step S3 is performed. As shown in FIG. 10, in the lamination step S3, a plurality of electrodes 11A, 12A, and 13A are laminated along the Z-axis direction (lamination direction). A separator 14 and a spacer 421 are provided between adjacent electrodes 11A, between the electrode 11A and the electrode 12A, and between the electrode 11A and the electrode 13A, respectively. Thereby, the laminate 10A is formed.

[0059] As shown in Fig. 11, in the laminate 10A, since the detection lines 60 of the electrodes 11A, 12A, and 13A protrude from the surface 15b of the current collector 15, a gap G is formed between the adjacent electrodes 11A, 12A, and 13A. Specifically, a gap G is formed between each spacer 421 and the seal member 411 adjacent to the spacer 421.

[0060] Fig. 12 is a cross-sectional view taken along the line XII-XII of Fig. 11. Fig. 13 is a cross-sectional view taken along the line XIII-XIII of Fig. 11. As shown in Figs. 11 to 13, in the overlapping region R1, since the detection line 60 is provided on the surface 15b of the current collector 15, the seal member 412 and the spacer 421 protrude toward the side opposite to the current collector 15. On the other hand, in the non-overlapping region R2, since the detection line 60 is not provided on the surface 15b of the current collector 15, the seal member 412 and the spacer 421 do not protrude toward the side opposite to the current collector 15. Therefore, in the overlapping region R1, the adjacent spacers 421 and the seal member 411 are in contact with each other, and in the non-overlapping region R2, a gap G is formed between the adjacent spacers 421 and the seal member 411. When the sealing step S5 is carried out in a state where such a gap G exists, there is a risk that the quality of the sealing on the side surface of the laminate 10A will deteriorate.

[0061] Subsequently, the restraint step S4 is carried out. In the restraint step S4, a load is applied to the laminate 10A by the first restraint plate 71 and the second restraint plate 72 from both sides of the laminate 10A in the Z-axis direction. In the restraint step S4, a load is applied to the non-overlapping region R2 of the seal member 412 of each electrode 11A, 12A, 13A.

[0062] Specifically, the detection lines 60 of the electrodes 11A, 12A, and 13A are separated from each other in the X-axis direction when viewed from the Z-axis direction. In the present embodiment, in the seal member 412 of each electrode 11A, 12A, 13A, the region overlapping all the detection lines 60 of the laminate 10A is the overlapping region R1, and the region not overlapping all the detection lines 60 of the laminate 10A is the non-overlapping region R2. The overlapping region R1 and the non-overlapping region R2 are arranged alternately along the X-axis direction.

[0063] In the restraining step S4, the laminate 10A is restrained by the first restraining plate 71 and the second restraining plate 72 in a state where the distance between the first restraining plate 71 and the second restraining plate 72 corresponding to the non-overlapping region R2 is smaller than the distance between the first restraining plate 71 and the second restraining plate 72 corresponding to the overlapping region R1. The first restraining plate 71 is disposed on one side in the Z-axis direction with respect to the laminate 10A such that each first region 71d faces each overlapping region R1 and each second region 71e faces each non-overlapping region R2. The second restraining plate 72 is disposed on the other side in the Z-axis direction with respect to the laminate 10A such that the flat second restraining surface 72a faces each overlapping region R1 and each non-overlapping region R2. The distance between the second region 71e of the first restraining plate 71 and the second restraining surface 72a of the second restraining plate 72 is smaller than the distance between the first region 71d of the first restraining plate 71 and the second restraining surface 72a of the second restraining plate 72.

[0064] When the laminate 10A is sandwiched between the first restraining plate 71 and the second restraining plate 72 in such a state, a load from each second region 71e of the first restraining plate 71 is applied to each non-overlapping region R2 of the laminate 10A. Thereby, the gap G between the electrodes 11A, 12A, 13A becomes smaller. In the present embodiment, the load is applied to the non-overlapping region R2 until the sealing member 411 and the spacer 421 adjacent to each other come into contact. In the present embodiment, the laminate 10A is restrained by the first restraining plate 71 and the second restraining plate 72 in a state where the second region 71e contacts the laminate 10A and the first region 71d is separated from the laminate 10A. The overlapping region R1 is pulled toward the detection line 60 by the tensile forces from the non-overlapping regions R2 on both sides of the overlapping region R1. Thereby, a load from the overlapping region R1 is applied to the detection line 60. That is, an indirect restraining load is applied to the overlapping region R1.

[0065] Subsequently, a sealing process S5 is performed. As shown in FIG. 14, in the sealing process S5, the side surface of the laminate 10A is sealed. Specifically, in the sealing process S5, while maintaining the constrained state of the constraining process S4, the outer peripheral portions 41b (see FIG. 9) of the respective seal members 412, the outer peripheral portions of the respective seal members 411, and the outer peripheral portions of the respective spacers 421 are melted, and thus the respective seal members 412, the respective seal members 411, and the respective spacers 421 are heated.

[0066] In the sealing process S5, the respective seal members 412, the respective seal members 411, and the respective spacers 421 are heated in a state where a load from the first region 71d of the first restraining plate 71 is applied to the non-overlapping region R2. In the sealing process S5, the respective seal members 412, the respective seal members 411, and the respective spacers 421 are heated by a non-contact type heater 73 that is separated from the laminate 10A. When the outer peripheral portions 41b of the respective seal members 412, the outer peripheral portions of the respective seal members 411, and the outer peripheral portions of the respective spacers 421 solidify, as a result of the outer peripheral portions 41b of the respective seal members 412, the outer peripheral portions of the respective seal members 411, and the outer peripheral portions of the respective spacers 421 being integrated, a welded portion 43 is formed. The side surface of the laminate 10A is sealed by the welded portion 43.

[0067] Subsequently, an injection molding process S6 is performed. In the injection molding process S6, in a state where a plurality of liquid injection port forming members are inserted into the laminate 10A, a liquid injection port portion 50 is formed by injection molding. Subsequently, the liquid injection port forming members are pulled out.

[0068] Subsequently, an electrolytic solution is injected into the internal space S through a plurality of liquid injection ports 20a (see FIG. 2). Subsequently, the plurality of liquid injection ports 20a are sealed by a sealing member 30 (see FIG. 1). Thereby, the power storage module 1 shown in FIGS. 1 and 2 is formed.

[0069] As described above, in the restraining step S4, the laminate 10A is restrained by the first restraining plate 71 and the second restraining plate 72 in a state where the distance between the first restraining plate 71 and the second restraining plate 72 corresponding to the non-overlapping region R2 is smaller than the distance between the first restraining plate 71 and the second restraining plate 72 corresponding to the overlapping region R1. As a result, a load is also applied to the region close to the detection line 60 (i.e., the region corresponding to the non-overlapping region R2 of the laminate 10A), so that the members adjacent to each other (in this embodiment, the seal member 411 and the spacer 421) come into contact with each other. Moreover, in the sealing step S5, the seal members 412, the seal members 411, and the spacers 421 are heated so that the outer peripheral portions of the seal members 412, the seal members 411, and the spacers 421 melt while the restraining state in the restraining step S4 is maintained. As a result, since the outer peripheral portions of the seal members 412, the seal members 411, and the spacers 421 melt while the above contact state is maintained, the formation of voids can be suppressed by reducing the gap G, and the quality of the sealing of the side surface of the laminate 10A is improved. Therefore, according to this manufacturing method, the side surface of the laminate 10A can be reliably sealed.

[0070] The first restraining surface 71a of the first restraining plate 71 facing the laminate 10a includes a first region 71d facing the overlapping region R1 and a second region 71e facing the non-overlapping region R2. In the restraining step S4, the laminate 10A is restrained by the first restraining plate 71 and the second restraining plate 72 in a state where the second region 71e contacts the laminate 10A and the first region 71d is separated from the laminate 10A. As a result, the non-overlapping region R2 of the laminate 10A is reliably pressed, so that the seal member 411 and the spacer 421 surely come into contact with each other in the non-overlapping region R2. Therefore, the side surface of the laminate 10A can be more reliably sealed.

[0071] In the sealing step S5, the seal members 412, the seal members 411, and the spacers 421 are heated by a non-contact type heater 73 separated from the laminate 10A. As a result, even if the detection line 60 extends outside the seal members 412, the seal members 411, and the spacers 421, melting of the outer peripheral portions of the seal members 412, the seal members 411, and the spacers 421 can be realized.

[0072] In the manufacturing apparatus 70, the first restraint surface 71a of the first restraint plate 71 includes a first region 71d facing the overlapping region R1 and a second region 71e facing the non-overlapping region R2. The distance between the second region 71e and the second restraint surface 72a of the second restraint plate 72 is smaller than the distance between the first region 71d and the second restraint surface 72a of the second restraint plate 72. As a result, a load is applied also to the region close to the detection line 60 (that is, the region corresponding to the non-overlapping region R2 of the laminate 10A), so that the members adjacent to each other (in this embodiment, the seal member 411 and the spacer 421) come into contact. Moreover, the heater 73 heats the seal members 412, the seal members 411, and the spacers 421 so that the outer peripheral portions of the seal members 412, the seal members 411, and the spacers 421 melt while the above-described restraint state is maintained. As a result, since the outer peripheral portions of the seal members 412, the seal members 411, and the spacers 421 melt while the above contact state is maintained, formation of voids can be suppressed by reducing the gap G, and the quality of the sealing of the side surface of the laminate 10A is improved. Therefore, according to the manufacturing apparatus 70, the side surface of the laminate 10A can be reliably sealed.

[0073] The second region 71e protrudes toward the laminate 10A more than the first region 71d. Thereby, a load can be reliably applied to the non-overlapping region R2.

[0074] The second restraint surface 72a of the second restraint plate 72 facing the laminate 10A is a flat surface. Thereby, a load can be reliably applied to the non-overlapping region R2.

[0075] The heater 73 heats the seal members 412, the seal members 411, and the spacers 421 in a state of being separated from the laminate 10A. Thereby, even if the detection line 60 extends outside the seal members 412, the seal members 411, and the spacers 421, melting of the outer peripheral portions of the seal members 412, the seal members 411, and the spacers 421 can be realized.

[0076] As described above, although one embodiment of the present invention has been described, the present invention is not limited to the above-described embodiment.

[0077] As shown in FIG. 15, the first region 71d of the first restraint plate 71 may be a partial region of the first restraint surface 71a. The second region 71e of the first restraint plate 71 may protrude from the first restraint surface 71a. In this case, the second region 71e may face the outer peripheral portion 41b of the seal member 412. The second region 71e may not face the inner peripheral portion 41a of the seal member 412.

[0078] The first active material layer 16 may be a negative electrode active material layer, and the second active material layer 17 may be a positive electrode active material layer.

[0079] The detection line 60 may be provided on the surface 15a of the current collector 15.

[0080] In the restraint step S4, a load may not be applied to the inner peripheral portion 41a of each seal member 412. In the restraint step S4, it is sufficient that a load is applied to a region (outer region R22 of the non-overlapping region R2) of the outer peripheral portion 41b of each seal member 412 that does not overlap with the detection line 60. Similarly, in the sealing step S5, a load may not be applied to the inner peripheral portion 41a of each seal member 412. In the sealing step S5, each seal member 412, each seal member 411, and each spacer 421 may be heated in a state where a load is applied to a region (outer region R22 of the non-overlapping region R2) of the outer peripheral portion 41b of each seal member 412 that does not overlap with the detection line 60.

[0081] The first restraint surface 71a of the first restraint plate 71 may be a flat surface. A load may be applied to a region (outer region R22 of the non-overlapping region R2) of the outer peripheral portion 41b of each seal member 412 that does not overlap with the detection line 60 so that the gap G between the electrodes 11A, 12A, and 13A becomes small.

[0082] The first restraining surface 71a of the first restraining plate 71 may be a flat surface, and the second restraining surface 72a of the second restraining plate 72 may include a first region facing each overlapping region R1, and a second region facing each non-overlapping region R2 and protruding toward the laminate 10A more than the first region of the second restraining surface 72a.

Explanation of reference numerals

[0083] 10A... laminate, 11A, 12A, 13A... electrodes, 15... current collector, 15b... surface, 17... second active material layer, 41a... inner peripheral portion, 41b... outer peripheral portion, 412... sealing member, 60... detection line, 70... manufacturing apparatus, 71... first restraining plate, 71a... first restraining surface, 71d... first region, 71e... second region, 72... second restraining plate, 72a... second restraining surface, 73... heater, R1... overlapping region, R2... non-overlapping region.

Claims

1. A lamination step of forming a laminate by laminating a plurality of electrodes along a lamination direction; A constraint step of applying a load to the laminate by a first constraint plate disposed on one side of the laminate in the lamination direction and a second constraint plate disposed on the other side of the laminate in the lamination direction; A sealing step of sealing the side surface of the laminate, and comprising: Each of the plurality of electrodes has a current collector, an active material layer provided on the surface of the current collector, a seal member provided on the surface of the current collector so as to surround the active material layer when viewed from the lamination direction, and a detection line electrically connected to the surface of the current collector; The detection lines of the plurality of electrodes extend outside the outer edge of the seal member along a first direction so as to overlap the seal member when viewed from the lamination direction and are arranged along a second direction intersecting the first direction; The seal members of the plurality of electrodes include a superimposed region that overlaps the detection line when viewed from the lamination direction and a non-superimposed region located between the superimposed regions adjacent to each other when viewed from the lamination direction; In the constraint step, the laminate is constrained by the first constraint plate and the second constraint plate in a state where the distance between the first constraint plate and the second constraint plate corresponding to the non-superimposed region is smaller than the distance between the first constraint plate and the second constraint plate corresponding to the superimposed region; A method for manufacturing a power storage module, in which the seal member of the plurality of electrodes is heated so that the seal member melts while the constraint state in the constraint step is maintained in the sealing step.

2. The first constraint surface of the first constraint plate facing the laminate includes a first region facing the superimposed region and a second region facing the non-superimposed region; In the constraint step, the laminate is constrained by the first constraint plate and the second constraint plate in a state where the second region contacts the laminate and the first region is separated from the laminate. The method for manufacturing a power storage module according to Claim 1.

3. In the sealing step, the seal member of the plurality of electrodes is heated by a non-contact heater. The method for manufacturing a power storage module according to Claim 1 or 2.

4. A first constraint plate disposed on one side of the laminate in the lamination direction for applying a load to the laminate having a plurality of electrodes laminated along the lamination direction; A second restraint plate that is disposed on the other side of the laminate in the stacking direction and applies a load to the laminate; A non-contact heater for heating the side surface of the laminate, and comprising: Each of the plurality of electrodes includes a current collector, an active material layer provided on the surface of the current collector, a seal member provided on the surface so as to surround the active material layer when viewed from the stacking direction, and a detection line electrically connected to the surface of the current collector. The detection lines of the plurality of electrodes extend outside the outer edge of the seal member along a first direction so as to overlap the seal member when viewed from the stacking direction, and are arranged along a second direction intersecting the first direction. The seal members of the plurality of electrodes include a superimposed region that overlaps the detection line when viewed from the stacking direction, and a non-superimposed region located between the superimposed regions adjacent to each other when viewed from the stacking direction. The first restraint surface of the first restraint plate facing the laminate includes a first region facing the superimposed region and a second region facing the non-superimposed region. A manufacturing apparatus for a power storage module, wherein the distance between the second region and the second restraint plate is smaller than the distance between the first region and the second restraint plate.

5. The manufacturing apparatus for a power storage module according to claim 4, wherein the second region protrudes more than the first region.

Images