Manufacturing method of power storage device and power storage device

Abstract

To provide a manufacturing method of a power storage device capable of suppressing damage to a film material for packing.SOLUTION: A manufacturing method includes steps of: preparing a module main body; melting a tip end of a frame part to form a burr-shaped part by pushing a sealing material abutted on the tip end of the frame part toward a proximal end of the frame part by a heating body, and partially dissolving the tip end of the frame part and the sealing material to seal the frame part; and removing the burr-shaped part formed on an outer peripheral edge of the frame part along at least a third direction intersecting a first direction and a second direction of the burr-shaped parts formed on the tip end of the frame part.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing an electricity storage device and an electricity storage device. [Background technology]

[0002] Patent Document 1 discloses an energy storage device. This energy storage device includes an electrode stack in which electrodes are stacked, a sealing body provided on the electrode stack, and an injected resin part bonded to the sealing body. The sealing body includes a plurality of communication holes that communicate with the outside of the liquid inlet surface that faces in a direction intersecting the electrode stacking direction. The injected resin part includes a main body part that partially covers the liquid inlet surface and a protruding frame part that surrounds an opening connected to the communication holes. The protruding frame part is sealed with a sheet member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2024-25497 Summary of the Invention [Problem to be solved by the invention]

[0004] When sealing a protruding frame portion of an energy storage device with a sheet material, if the sheet material is welded to the protruding frame portion, burrs may be formed on the tip of the protruding frame portion due to heating. For example, if the energy storage device is packed with a film material, the burrs may damage the film material.

[0005] The present disclosure provides a method for manufacturing an electricity storage device that can suppress damage to film materials used for packing. [Means for solving the problem]

[0006] A method for manufacturing an energy storage device according to one aspect of the present disclosure includes the steps of: preparing a module body including a laminate including a plurality of electrodes stacked in a first direction; a sealing body portion that seals a side of the laminate along the first direction and has a through hole that communicates with the internal space of the laminate; and a frame portion that surrounds the through hole when viewed from a second direction intersecting the first direction and protrudes further in the second direction than the sealing body portion; pushing a sealing material abutted against the tip of the frame portion toward the base end of the frame portion with a heating element to melt the tip of the frame portion and form a burr-like portion, and partially dissolving the tip of the frame portion and the sealing material to seal the frame portion; and removing the burr-like portion formed at the tip of the frame portion, at least the burr-like portion formed on the outer peripheral edge of the frame portion along a third direction intersecting the first direction and the second direction.

[0007] In the manufacturing method for the energy storage device described above, the tip of the frame melted by the heating element becomes compatible with the sealing material, thereby sealing the frame with the sealing material. At this time, the sealing material abutting the tip of the frame is pressed toward the base end of the frame by the heating element, thereby reliably bonding the sealing material to the frame. As the sealing material is pressed by the heating element, burrs are formed on the tip of the frame. However, by removing the burrs formed on the outer peripheral edge of the frame, damage to the film material by the burrs is suppressed, even if the energy storage device is packed with a film material.

[0008] In one example, the step of removing the burr-like portion may involve removing the burr-like portion using a cutting blade that moves along a third direction that intersects the first direction and the second direction, using an end face of the module body that intersects the first direction as a reference height position.

[0009] An energy storage device according to one aspect of the present disclosure includes a stack including a plurality of electrodes stacked in a first direction, a sealing body that seals a side surface of the stack along the first direction and has a through-hole that communicates with an internal space of the stack, a frame that surrounds the through-hole when viewed from a second direction intersecting the first direction and protrudes in the second direction beyond the sealing body, and a sealing material that seals a tip of the frame. The tip of the frame has a burr-like portion joined to the sealing material at its inner peripheral edge, and does not have a burr-like portion at least at a position of its outer peripheral edge along a third direction intersecting the first direction and the second direction. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to provide a method for manufacturing an electricity storage device that can suppress damage to film materials used for packing. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic plan view of an example of a power storage device. [Figure 2] FIG. 2 is a schematic diagram showing one side of a module main body that constitutes an example of a power storage device. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a flow chart showing an example of a method for manufacturing a power storage device. [Figure 5] FIG. 5 is a schematic diagram showing each step in an example of the manufacturing method. [Figure 6] FIG. 6 is a schematic diagram showing each step in an example of the manufacturing method. [Figure 7] FIG. 7 is a schematic diagram showing each step in an example of the manufacturing method. [Figure 8] FIG. 8 is a schematic diagram showing a processing device used in one example of the manufacturing method. [Figure 9] FIG. 9 is a perspective view schematically illustrating an exterior pack of an example of a power storage device. DETAILED DESCRIPTION OF THE INVENTION

[0012] An embodiment will be described below with reference to the drawings. In the description of the drawings, identical or equivalent elements are denoted by the same reference numerals, and redundant description may be omitted. In the description, a Cartesian coordinate system defined by the X-axis, Y-axis, and Z-axis shown in the drawings may be referenced.

[0013] FIG. 1 is a schematic plan view showing a power storage device according to this embodiment. The power storage device 1 is a power storage device used in batteries for various vehicles such as forklifts, hybrid vehicles, and electric vehicles. The power storage device 1 is a secondary battery such as a nickel-metal hydride secondary battery or a lithium-ion secondary battery. The power storage device 1 may also be an electric double layer capacitor. Here, the case where the power storage device 1 is a lithium-ion secondary battery is shown.

[0014] The energy storage device 1 includes a module body 1A and a sealing material 54. The module body 1A has a rectangular shape when viewed in the Z-axis direction (first direction) and has four outer side surfaces 20s extending in the Z-axis direction. The outer side surfaces 20s are configured with outer side surfaces 20sA and 20sB facing each other in the Y-axis direction (second direction) and outer side surfaces 20sC and 20sD facing each other in the X-axis direction (third direction). Both end surfaces of the module body 1A in the Z-axis direction are configured with a positive terminal electrode 12 and a negative terminal electrode 13, as described below, and are used for extracting power. A liquid injection frame 50 is provided on the outer side surface 20sA of the module body 1A and is used when injecting an electrolyte into the module body 1A.

[0015] FIG. 2 is a schematic diagram of a module body constituting the energy storage device, as viewed from the Y direction. FIG. 3 is a cross-sectional view taken along line IV-IV in FIG. 2. As shown in FIGS. 2 and 3, the module body 1A includes an electrode stack 10 and a sealing body 29 that surrounds the electrode stack 10 when viewed from the Z axis direction. The electrode stack 10 includes multiple electrodes stacked along the Z axis direction. The Z axis direction is the stacking direction of the electrodes, which is the thickness direction of the energy storage device 1. The multiple electrodes include multiple bipolar electrodes 11, a positive terminal electrode 12, and a negative terminal electrode 13. A separator 14 is interposed between adjacent electrodes. A pair of electrodes adjacent in the stacking direction forms one cell.

[0016] The bipolar electrode 11 includes a current collector 15, a positive electrode active material layer 16 provided on one surface of the current collector 15, and a negative electrode active material layer 17 provided on the other surface of the current collector 15. The current collector 15 is rectangular and sheet-shaped when viewed from the Z-axis direction. The active material layers (positive electrode active material layer 16, negative electrode active material layer 17) are provided in the center of the current collector 15 when viewed from the Z-axis direction, and a peripheral portion 15c of the current collector 15 is a so-called uncoated portion where no active material layer is provided. The positive electrode active material layer 16 is provided on a first surface 15a of the current collector 15. The negative electrode active material layer 17 is provided on a second surface 15b of the current collector 15, which is the surface opposite to the first surface 15a. The first surface 15a of the current collector 15 faces the negative side in the Z-axis direction, and the second surface 15b of the current collector 15 faces the positive side in the Z-axis direction. The multiple bipolar electrodes 11 are stacked so that the positive electrode active material layer 16 of one bipolar electrode 11 and the negative electrode active material layer 17 of the other bipolar electrode 11 adjacent in the stacking direction face each other with the separator 14 interposed therebetween.

[0017] The positive terminal electrode 12 has a current collector 15 and a positive electrode active material layer 16 provided on a first surface 15a of the current collector 15. No active material layer is provided on a second surface 15b of the current collector 15 of the positive terminal electrode 12. In other words, the second surface 15b of the current collector 15 of the positive terminal electrode 12 constitutes the positive electrode terminal surface of the energy storage device 1. The positive terminal electrode 12 is laminated on the bipolar electrode 11 at the positive end of the electrode laminate 10 in the Z-axis direction. The positive terminal electrode 12 is laminated on the bipolar electrode 11 so that the positive electrode active material layer 16 faces the negative electrode active material layer 17 of the bipolar electrode 11 with the separator 14 interposed therebetween.

[0018] The negative electrode terminal electrode 13 has a current collector 15 and a negative electrode active material layer 17 provided on a second surface 15b of the current collector 15. No active material layer is provided on a first surface 15a of the current collector 15 of the negative electrode terminal electrode 13. That is, the first surface 15a of the current collector 15 of the negative electrode terminal electrode 13 constitutes the negative electrode terminal surface of the energy storage device 1. The negative electrode terminal electrode 13 is laminated on the bipolar electrode 11 at the negative end of the electrode laminate 10 in the Z-axis direction. The negative electrode terminal electrode 13 is laminated on the bipolar electrode 11 so that the negative electrode active material layer 17 faces the positive electrode active material layer 16 of the bipolar electrode 11 with the separator 14 interposed therebetween. In this embodiment, the current collectors of the bipolar electrode 11, the positive terminal electrode 12, and the negative terminal electrode 13 are denoted by the same reference numeral 15, but the current collectors of the bipolar electrode 11, the positive terminal electrode 12, and the negative terminal electrode 13 may be the same as or different from one another.

[0019] Separators 14 are disposed between adjacent bipolar electrodes 11, between the positive terminal electrode 12 and the bipolar electrode 11, and between the negative terminal electrode 13 and the bipolar electrode 11. Separators 14 are interposed between the positive electrode active material layer 16 and the negative electrode active material layer 17, and separate the positive electrode active material layer 16 from the negative electrode active material layer 17. Separators 14 allow charge carriers such as lithium ions to pass through while preventing short circuits due to contact between adjacent electrodes.

[0020] The current collector 15 is a chemically inactive electrical conductor that allows current to continue to flow through the positive electrode active material layer 16 and the negative electrode active material layer 17 during charging or discharging of the lithium-ion secondary battery. The material of the current collector 15 is, for example, a metal material, a conductive resin material, or a conductive inorganic material. Examples of conductive resin materials include resins obtained by adding a conductive filler to a conductive polymer material or a non-conductive polymer material as needed. The current collector 15 may have multiple layers. In this case, each layer of the current collector 15 may contain the above-mentioned metal material or conductive resin material.

[0021] A coating layer may be formed on the surface of the current collector 15. The coating layer may be formed by a known method such as plating or spray coating. The current collector 15 may be, for example, in the form of a plate, foil (e.g., metal foil), film, or mesh. Examples of metal foils include aluminum foil, copper foil, nickel foil, titanium foil, and 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 in the form of a foil, the thickness of the current collector 15 may be, for example, 1 μm to 100 μm. In this embodiment, the current collector 15 is an aluminum foil, or a foil obtained by bonding and integrating aluminum foil and copper foil together.

[0022] The positive electrode active material layer 16 contains a positive electrode active material capable of absorbing and releasing charge carriers such as lithium ions. Examples of the positive electrode active material include lithium composite metal oxides having a layered rock salt structure, metal oxides having a spinel structure, and polyanion compounds. Any positive electrode active material may be used as long as it is usable in lithium ion secondary batteries. The positive electrode active material layer 16 may contain multiple positive electrode active materials. In this embodiment, the positive electrode active material layer 16 contains olivine-type lithium iron phosphate (LiFePO4) as a composite oxide.

[0023] The negative electrode active material layer 17 contains a negative electrode active material capable of absorbing and releasing charge carriers such as lithium ions. The negative electrode active material may be any of a simple substance, an alloy, or a compound. Examples of the negative electrode active material include Li, carbon, and metal compounds. The negative electrode active material may be an element or a compound thereof that can be alloyed with lithium. Examples of carbon include natural graphite, artificial graphite, hard carbon (non-graphitizable carbon), and soft carbon (easily graphitizable carbon). Examples of artificial graphite include highly oriented graphite and mesocarbon microbeads. Examples of elements that can be alloyed with lithium include silicon and tin. In this embodiment, the negative electrode active material layer 17 contains graphite as a carbon-based material.

[0024] Each of the positive electrode active material layer 16 and the negative electrode active material layer 17 (hereinafter sometimes simply referred to as "active material layer") may further contain, as necessary, a conductive additive to enhance electrical conductivity, a binder, an electrolyte (polymer matrix, ion-conductive polymer, electrolyte solution, etc.), an electrolyte supporting salt (lithium salt) to enhance ionic conductivity, etc. The conductive additive is added to enhance the conductivity of each electrode (bipolar electrode 11, positive terminal electrode 12, negative terminal electrode 13). Examples of the conductive additive include acetylene black, carbon black, graphite, and carbon nanotubes.

[0025] Examples of binders include fluorine-containing resins such as polyvinylidene fluoride, polytetrafluoroethylene, and fluororubber; thermoplastic resins such as polypropylene and polyethylene; imide resins such as polyimide and polyamideimide; alkoxysilyl group-containing resins; acrylic resins such as acrylic acid and methacrylic acid; styrene-butadiene rubber (SBR); carboxymethyl cellulose; alginates such as sodium alginate and ammonium alginate; water-soluble cellulose ester crosslinked bodies; and starch-acrylic acid graft polymers. These binders can be used alone or in combination. Examples of solvents that can be used include water and N-methyl-2-pyrrolidone (NMP).

[0026] The separator 14 may be, for example, a porous sheet or nonwoven fabric containing a polymer that absorbs and retains an electrolyte. Examples of materials for the separator 14 include polypropylene, polyethylene, polyolefin, and polyester. The separator 14 may have a single-layer structure or a multilayer structure. The multilayer structure may include, for example, a ceramic layer as an adhesive layer or a heat-resistant layer. The separator 14 may be impregnated with an electrolyte. The separator 14 may be composed of an electrolyte such as a polymer electrolyte or an inorganic electrolyte. Examples of the electrolyte impregnated in the separator 14 include a liquid electrolyte (electrolytic solution) containing a nonaqueous solvent and an electrolyte salt dissolved in the nonaqueous solvent, and a polymer gel electrolyte containing an electrolyte retained in a polymer matrix.

[0027] When the separator 14 is impregnated with an electrolytic solution, known lithium salts such as LiClO4, LiAsF6, LiPF6, LiBF4, LiCF3SO3, LiN(FSO2)2, and LiN(CF3SO2)2 may be used as the electrolyte salt. Furthermore, known solvents such as cyclic carbonates, cyclic esters, chain carbonates, chain esters, and ethers may be used as the nonaqueous solvent. Two or more of these known solvent materials may be used in combination.

[0028] The seal 29 includes a seal body 20 and a liquid injection frame 50 provided in a portion of the seal body 20. The seal body 20 is formed in a frame shape around the periphery of the electrode stack 10 so as to surround the periphery of the electrode stack 10 when viewed in the Z-axis direction. The seal body 20 can be joined to the first surface 15a and the second surface 15b of each current collector 15 at the peripheral portion 15c of the current collector 15. The seal body 20 separates adjacent current collectors 15 in the Z-axis direction, forming internal spaces S therebetween, and can seal each of these internal spaces S. That is, the seal body 20 seals each cell formed by a pair of electrodes adjacent in the stacking direction. In this embodiment, each internal space S can contain an electrolyte (not shown). That is, the seal body 20 cooperates with adjacent current collectors 15 in the Z-axis direction to define an internal space S that contains the electrolyte. The seal body 20 can prevent the electrolyte solution contained in the internal space S from leaking out to the outside.

[0029] The seal body 20 can prevent air, moisture, and the like from entering and leaving between the outside of the electrode stack 10 and the internal space S. The seal body 20 can prevent, for example, gas generated in each electrode due to a charge / discharge reaction from leaking to the outside of the module body 1A. The edge of the separator 14 is joined to the seal body 20. The seal body 20 contains an insulating material. Examples of materials for the seal body 20 include various resin materials such as polypropylene, polyethylene, polystyrene, ABS resin, acid-modified polypropylene, acid-modified polyethylene, and acrylonitrile-styrene resin.

[0030] An example of the seal body 20 includes a plurality of seal materials 21, a pair of end seal materials 24, and a plurality of spacers 22. The seal materials 21, the end seal materials 24, and the spacers 22 may be frame-shaped members formed in a sheet shape. The seal body 20 also has a welded end portion 23. The seal material 21 is frame-shaped when viewed from the Z-axis direction and is provided along the peripheral edge portion 15c of the current collector 15. The seal material 21 is provided so as to extend from the first surface 15a of the current collector 15, across the end face, to the second surface 15b, and covers the peripheral edge portion 15c. That is, on the first surface 15a and the second surface 15b of the current collector 15, the seal material 21 has an inner portion overlapping the current collector 15 and an outer portion located outside the edge of the current collector 15, when viewed from the Z direction. The outer portions of a pair of seal materials 21 adjacent to each other across the current collector 15 are connected to each other. The sealant 21 can be welded to at least one of the first surface 15a and the second surface 15b of the current collector 15. In this embodiment, the sealant 21 is welded to both the first surface 15a and the second surface 15b of the current collector 15.

[0031] The end seal material 24 has a frame shape when viewed in the Z-axis direction and is provided along the peripheral edge 15c of the current collector 15 constituting each of the positive and negative terminal electrodes 12 and 13. Therefore, the end seal material 24 is arranged to sandwich the plurality of seal materials 21 in the Z-axis direction. The end seal material 24 can be welded to at least one of the first surface 15a and the second surface 15b of the current collector 15. The end seal material 24 of this embodiment is welded to both the first surface 15a and the second surface 15b of the current collector 15. The end seal material 24 may be configured by laminating, on a resin layer bonded to the current collector 15, a gas barrier layer made of a resin with lower gas permeability than the resin layer.

[0032] The spacer 22 has a frame shape when viewed from the Z-axis direction, and is arranged along the peripheral edge 15c of the current collector 15. The spacer 22 is arranged so as to be interposed between the seal materials 21 adjacent to each other in the Z-axis direction. The spacer 22 is also arranged so as to be interposed between the seal materials 21 and the end seal materials 24 adjacent to each other in the Z-axis direction. The spacer 22 can maintain the distance between the current collectors 15 adjacent to each other in the Z-axis direction. In other words, the spacer 22, the seal materials 21, and the end seal materials 24 define an internal space S between the adjacent current collectors 15.

[0033] The welded end portion 23 is formed by welding together and integrating the ends of the multiple sealants 21, the pair of end sealants 24, and the multiple spacers 22 on the opposite side to the internal space S. When viewed from the Z-axis direction, the welded end portion 23 has a frame shape that surrounds the electrode stack 10. The side of the welded end portion 23 on the opposite side to the internal space S extends along the Z-axis direction and forms the outer surface 20s of the seal main body 20. In other words, the seal main body 20 includes the outer surface 20s on the opposite side to the internal space S. The outer surface 20s may be formed as a flat surface.

[0034] The seal main body 20 has a plurality of communication holes 27 that communicate with each of the plurality of internal spaces S. As an example, the communication holes 27 are configured by forming cutout portions by cutting out a portion of the frame-shaped spacer 22 in a plan view. The communication holes 27 are through holes that penetrate the welded end portion 23. Each communication hole 27 has one opening in the internal space S and the other opening on the outer surface 20s of the seal main body 20. In the illustrated example, an opening is formed on the outer surface 20sA.

[0035] The liquid filling frame 50 is formed so as to overlap the region of the outer surface 20sA where the communication holes 27 are formed. The liquid filling frame 50 is made of resin and is joined to the welding end portion 23. For example, the liquid filling frame 50 is formed by injection molding of resin. The liquid filling frame is integrally joined to the welding end portion 23 by the heat generated during injection molding. One example of the liquid filling frame 50 includes a main body portion 51, a protruding frame portion 53 (frame portion), and an overhang portion 55.

[0036] The main body 51 partially covers the outer surface 20sA. For example, the main body 51 covers the outer surface 20sA so as to include the region where the plurality of communication holes 27 are formed on the outer surface 20sA. As described above, the plurality of communication holes 27 are connected to the plurality of internal spaces S. In the example shown in FIG. 2 , 30 communication holes 27 corresponding to the 30 internal spaces formed between the current collectors 15 are discretely arranged in the X-axis direction and the Z-axis direction. More specifically, the communication holes 27 corresponding to the internal spaces of the first to tenth layers, with the positive terminal electrode 12 as the base end, are arranged at equal intervals along the X-axis direction, and the communication holes 27 corresponding to the internal spaces of the eleventh to twentieth layers and the communication holes 27 corresponding to the internal spaces of the twenty-first to thirtieth layers are arranged in order below the internal spaces of the first to tenth layers in the Z-axis direction. The main body 51 extends in a rectangular shape along the X-axis direction and the Z-axis direction to cover the area in which the 30 communication holes 27 are formed.

[0037] The main body 51 is formed in the shape of a rectangular plate having a predetermined thickness in the Y-axis direction. The main body 51 has a liquid injection port 52 that opens at a position corresponding to the communication hole 27. In other words, the communication hole 27 and the liquid injection port 52 communicate with each other.

[0038] The protruding frame portion 53 protrudes along the Y-axis direction from the main body portion 51 as a base end. When viewed from the Y-axis direction, the protruding frame portion 53 surrounds each of the liquid filling ports 52 (communication holes 27) and functions as a partition wall that separates each of the liquid filling ports 52. In the example of Fig. 2, ten protruding frame portions 53, each having three spaces formed therein to separate three liquid filling ports 52 aligned in the Z-axis direction, are arranged in the X-axis direction.

[0039] As an example, the protruding frame portions 53 are used when injecting the electrolyte solution into each of the internal spaces S. For example, when injecting the electrolyte solution, a nozzle of a liquid injection device is brought into close contact with the top surface of the protruding frame portions 53, and the electrolyte solution is introduced from the nozzle into the space of each of the protruding frame portions 53. This makes it possible to inject the electrolyte solution into the internal spaces S through the liquid injection port 52 and the communication hole 27. After the electrolyte solution is injected, a sealant 54 for sealing the internal spaces S of each cell is provided on the protruding frame portions 53. The sealant 54 is a sheet-like or plate-like member. For example, the sealant 54 is a rectangular sheet that can collectively cover the multiple protruding frame portions 53 provided on the liquid injection frame 50.

[0040] In one example, the main body 51 includes a terminal 58 for voltage detection. The terminal 58 is formed in a position on the main body 51 that is shifted toward the positive side in the X-axis direction relative to the multiple protruding frame portions 53. For example, the terminal 58 is provided adjacent to the protruding frame portion 53 formed at the end on the positive side in the X-axis direction, with the flat surface 51a interposed therebetween. In one example, the terminal 58 is provided at the end on the positive side in the X-axis direction of the main body 51. The terminal 58 provides multiple terminals 58a electrically connected to the multiple current collectors 15, respectively. One end of the terminal 58a is connected to the corresponding current collector 15, and the other end of the terminal 58a is exposed from the main body 51. The terminals 58a may be, for example, metal pins, as long as they are electrically connected to the current collectors 15.

[0041] The overhang portions 55 are provided on both end edges of the main body 51 in the Z-axis direction. The overhang portions 55 partially cover both end edges of the welded end 23 in the Z-axis direction. For example, the overhang portions 55 partially cover the end seal material 24 joined to the positive terminal electrode 12. In the illustrated example, the end edge 55a of the overhang portion 55 extends from the end edge of the welded end 23 to a position outside the inner edge 22a of the spacer 22 and the inner edge 21a of the seal material 21 when viewed in the Z-axis direction, but this is not limited thereto. The overhang portions 55 may be formed in the shape of a rectangular plate having the same length as the main body 51 in the X-axis direction.

[0042] Next, a description will be given of a method for manufacturing the energy storage device 1. Fig. 4 is a flow diagram showing a method for manufacturing the energy storage device 1. Figs. 5 to 7 are diagrams schematically showing each step in an example of the manufacturing method.

[0043] In one example of a manufacturing method, first, a module main body 1A is prepared (preparation step S10). The manufacturing method of the module main body 1A is not particularly limited. As an example, electrodes to which a sealing material 21 or an edge sealing material 24 is attached are stacked. Spacers 22 are disposed between the sealing materials 21 attached to adjacent electrodes in the stacking direction, and between the sealing material 21 and the edge sealing material 24. Separators 14 are also disposed between adjacent electrodes in the stacking direction. The spacers 22 are provided with cutouts for forming communication holes 27. A plate for forming a liquid injection port is disposed in the cutouts of the spacers, and the peripheral edges of the sealing materials 21, edge sealing materials 24, and spacers 22 adjacent in the stacking direction are welded to each other. Thereafter, the module main body 1A is placed in an injection mold, and a liquid injection frame 50 is formed in a part of the sealing main body 20 by injection molding. The plate is pulled out of the communication hole 27 to form a liquid injection port 52. In this manner, the module main body 1A is prepared. The electrolyte solution is poured into the internal space S of the prepared module body 1A through the pouring port 52. When the electrolyte solution is poured into the module body 1A, the electrolyte solution may permeate the pouring frame 50. For example, the electrolyte solution may be poured in a state in which the module body 1A is upright so that the pouring port 52 faces upward.

[0044] Subsequently, each cell formed in the module main body 1A is sealed (sealing step S20). In the sealing step S20, a sealant 54 is welded to the protruding frame portion 53 surrounding the communication hole 27 (liquid inlet 52). That is, by attaching the sealant 54 to the protruding frame portion 53, the cell space including the liquid inlet 52, the communication hole 27, and the internal space S is sealed.

[0045] In an example of the sealing step S20, first, the protruding frame portion 53 of the liquid filling frame 50 is temporarily sealed in a reduced-pressure environment (first temporary sealing step S21). In an example of the first temporary sealing step S21, the protruding frame portion 53 is temporarily sealed by a hot plate welding device 81. The hot plate welding device 81 has a hot plate 81a (heating body), which is a plate body that can be heated to a desired temperature by a heat source such as a heater. In an example of the hot plate 81a, a flat contact surface 81b that contacts an object. For example, the hot plate 81a may be supported by a moving mechanism that can reciprocate in one direction. In the illustrated example, the hot plate 81a is arranged so as to be reciprocable along the Y-axis direction of the module body 1A. In this example, the Y-axis direction of the module body 1A is aligned with the vertical direction, and the hot plate 81a is reciprocable along the vertical direction. The contact surface 81b of the hot plate 81a is set so as to be perpendicular to the vertical direction (i.e., so as to coincide with a horizontal plane).

[0046] In the first temporary sealing step S21, the hot plate 81a is moved along the Y-axis direction toward the module main body 1A (see FIGS. 5(a) and 5(b)). The hot plate 81a moves to a position where it abuts against the entire tip of the protruding frame portion 53. A sealing material 56 (first temporary sealing material) is disposed between the protruding frame portion 53 and the hot plate 81a, and as the hot plate 81a moves, the sealing material 56 is sandwiched between the protruding frame portion 53 and the hot plate 81a. The sealing material 56 is a sheet-like or plate-like member. For example, the sealing material 56 is a rectangular sheet having a size that allows it to collectively cover the multiple protruding frame portions 53 provided on the liquid filling frame 50.

[0047] The sealing material 56 has, on its inner surface facing the protruding frame portion 53, a resin layer 56a (low-melting point sealing material) made of a resin material with a lower melting point than the resin material making up the protruding frame portion 53. For example, if the protruding frame portion 53 is made of polyethylene, the resin layer 56a may also be made of polyethylene. In this case, the resin layer 56a may be made of a resin material with a relatively low melting point, such as low-density polyethylene, and the protruding frame portion 53 may be made of high-density polyethylene, which has a relatively high melting point, so that the melting point of the resin layer 56a is lower than that of the protruding frame portion 53.

[0048] Furthermore, the sealing material 56 has a surface layer made of a material with a higher melting point than the resin layer 56a on the surface opposite the side of the resin layer 56a facing the protruding frame portion 53. The surface layer may be made of a resin material. In this embodiment, the sealing material 56 has a resin layer 56b as the surface layer. The melting point of the resin layer 56b may be higher than the melting point of the protruding frame portion 53. For example, if the resin layer 56a is made of low-density polyethylene with a relatively low melting point, the resin layer 56b may be made of polypropylene with a relatively high melting point. In one example, the protruding frame portion 53 may be made of polyethylene with a melting point of about 130°C, the resin layer 56a may be made of polyethylene with a melting point of about 110°C, and the resin layer 56b may be made of polypropylene with a melting point of about 160°C.

[0049] In the first temporary sealing step S21, the hot plate 81a is heated to a first temperature (e.g., approximately 120°C) that is lower than the melting point of the material constituting the protruding frame portion 53 but higher than the melting point of the material constituting the resin layer 56a of the sealing material 56. The sealing material 56 is arranged so that the resin layer 56a faces the protruding frame portion 53 and the resin layer 56b faces the hot plate 81a. The hot plate 81a heated to the first temperature presses the sealing material 56 against the tip of the protruding frame portion 53, whereby the sealing material 56 is sandwiched between the protruding frame portion 53 and the hot plate 81a with the resin layer 56a melted. At this time, because the protruding frame portion 53 does not melt, the sealing material 56 is not fused to the protruding frame portion 53 but is bonded to the protruding frame portion 53 in an incompatible state. Because the sealing material 56 bonded to the protruding frame portion 53 is incompatible with the protruding frame portion 53, it is in a state where it can be peeled off from the protruding frame portion 53. In this embodiment, the first temporary sealing step S21 is a temporary sealing step using a sealing material melting method. After the sealing material 56 is pressed into the protruding frame portion 53 by the hot plate 81a, the hot plate 81a returns to the standby position.

[0050] In one example of the temporary sealing step S21, after the protruding frame portion 53 is sealed, initial charging, aging, etc. of the module main body 1A are performed. For example, initial charging, aging, etc. are performed in a state where a hole is opened in the sealing material 56 that seals the protruding frame portion 53 of the liquid filling frame 50. This hole connects the internal space S with the outside of the module main body 1A. Gas generated in the internal space S due to aging is released to the outside of the module main body 1A through the hole.

[0051] Next, the sealing material 56 is removed from the protruding frame portion 53 (first removal step S22). As described above, the temporarily sealed sealing material 56 is releasably bonded to the protruding frame portion 53, and therefore, when the sealing material 56 is peeled off, the end face of the protruding frame portion 53 is exposed.

[0052] Next, in a reduced-pressure environment, the protruding frame portion 53 of the liquid filling frame 50 is temporarily sealed (second temporary sealing step S23). In one example of the second temporary sealing step S23, the protruding frame portion 53 is temporarily sealed by a hot plate welding device 81. In the second temporary sealing step S23, the hot plate 81a is moved along the Y-axis direction toward the module main body 1A (see FIGS. 6(a) and 6(b)). The hot plate 81a moves to a position where it abuts against the entire tip of the protruding frame portion 53. A sealing material 57 (second temporary sealing material) is disposed between the protruding frame portion 53 and the hot plate 81a. As the hot plate 81a moves, the sealing material 57 is sandwiched between the protruding frame portion 53 and the hot plate 81a. The sealing material 57 is a sheet-like or plate-like member. For example, the sealing material 57 is a rectangular sheet having a size that allows it to collectively cover the multiple protruding frame portions 53 provided on the liquid filling frame 50.

[0053] In this embodiment, the sealing material 57 may be composed of a single layer of resin layer 57a (high-melting-point sealing material). The resin layer 57a may be formed from the same resin as the resin layer 56b. When the same sealing material 56 as the first temporary sealing material is used as the second temporary sealing material, the sealing material 56 is arranged so that the resin layer 56b (high-melting-point sealing material) faces the protruding frame portion 53 and the resin layer 56a faces the hot plate 81a. In this case, a release sheet may be arranged between the hot plate 81a and the sealing material 56 to prevent the sealing material 56 from adhering to the hot plate 81a.

[0054] The hot plate 81a is heated to a second temperature (e.g., about 140°C) that is higher than the melting point of the material constituting the protruding frame portion 53 but lower than the melting point of the material constituting the resin layer 57a of the sealing material 57. The hot plate 81a presses the sealing material 57 against the protruding frame portion 53, so that the sealing material 57 is sandwiched between the protruding frame portion 53 and the hot plate 81a while the leading end of the protruding frame portion 53 is melted. The leading end of the protruding frame portion 53 is pressed into the hot plate 81a via the sealing material 57, deforming and spreading along the XZ plane, forming a burr-like portion 53a (protruding portion) (see FIG. 6(b)). The burr-like portion is a residue outside the geometric shape of the edge (the portion where two surfaces intersect) of the component. More specifically, it is a portion where the melted and deformed resin solidifies and protrudes outside the original shape of the protruding frame portion 53.

[0055] Because the resin layer 57a does not melt, the sealing material 57 is not welded to the protruding frame portion 53, but is joined to the protruding frame portion 53 in an incompatible state. The sealing material 57 joined to the protruding frame portion 53 is incompatible with the protruding frame portion 53, and is therefore in a state where it can be peeled off from the protruding frame portion 53. In this embodiment, the second temporary sealing step S24 is a temporary sealing step using a frame melting method. After the sealing material 57 is pressed into the protruding frame portion 53 by the hot plate 81a, the hot plate 81a returns to the standby position.

[0056] After the module body 1A is temporarily sealed in the second temporary sealing step S23, the self-discharge characteristics of the module body 1A are inspected. In the self-discharge characteristic inspection, the temporarily sealed module body 1A is left in a predetermined environment for a certain period of time. This causes the module body 1A to self-discharge. During the self-discharge characteristic inspection, air permeates into the internal space S of the module body 1A, causing the internal space S to regain pressure compared to the state before the inspection began. Therefore, the sealing material 57 is then removed from the protruding frame portion 53 of the liquid filling frame 50 (second removal step S24). As described above, the temporarily sealed sealing material 57 is releasably joined to the protruding frame portion 53, and therefore, when the sealing material 57 is peeled off, the end face of the protruding frame portion 53 is exposed.

[0057] Next, in a reduced pressure environment, a sealant 54 is attached to the protruding frame portions 53 of the liquid filling frame 50, thereby performing a final sealing (final sealing step S25). In the final sealing step S25, the protruding frame portions 53 and the sealant are welded together by a hot plate welding device 81. A hot plate 81a of the hot plate welding device 81 is moved along the Y-axis direction toward the module main body 1A. The hot plate 81a moves to a position where it abuts against the entire tips of the multiple protruding frame portions 53 (see FIGS. 7(a) and 7(b)).

[0058] A sealing material 54 (main sealing material) is disposed between the hot plate 81a and the protruding frame portion 53, and as the hot plate 81a moves, the sealing material 54 is sandwiched between the protruding frame portion 53 and the hot plate 81a. The sealing material 54 has a resin layer 54a made of a resin material on an inner surface facing the protruding frame portion 53 and on a surface opposite to the side facing the protruding frame portion 53. The resin layer 54a may be made of a material with a lower melting point than the resin material constituting the protruding frame portion 53, or may be made of the same material as the resin layer 56a.

[0059] The sealing material 54 also has an intermediate layer made of a material with excellent gas barrier properties between the front and back resin layers 54a. The intermediate layer may be made of a resin material. In this embodiment, the sealing material 54 has a resin layer 54b as the intermediate layer. The melting point of the resin layer 54b may be higher than the melting point of the protruding frame portion 53. For example, the resin layer 54b may be made of an ethylene-vinyl alcohol copolymer.

[0060] The hot plate 81a is heated to a temperature (e.g., about 140°C) higher than the melting point of the material constituting the protruding frame portion 53 and the material constituting the resin layer 54a of the sealing material 54. When the hot plate 81a presses the sealing material 54 against the protruding frame portion 53, the resin layer 54a of the sealing material 54 melts, and the sealing material 54 is sandwiched between the protruding frame portion 53 and the hot plate 81a with the tip of the protruding frame portion 53 melting. A release sheet may be disposed between the hot plate 81a and the sealing material 54 to prevent the sealing material 54 from adhering to the hot plate 81a. The sealing material 54 is bonded (i.e., welded) to the protruding frame portion 53 with the resin layer 54a and the tip of the protruding frame portion 53 compatible with each other. The tip of the protruding frame portion 53 is pressed into the hot plate 81a via the sealing material 54, further deforming and expanding along the XZ plane. This expands the burr-like portion 53a. A part of the expanded flash-like portion 53b may be compatible with the sealing material 54. After the sealing material 54 is pressed into the protruding frame portion 53 by the hot plate 81a, the hot plate 81a returns to the standby position.

[0061] Next, of the burr-like portions 53b formed at the tip of the protruding frame portion 53, at least the burr-like portions 53b formed on the outer peripheral edge of the protruding frame portion along the X-axis direction are removed together with the excess portion 54C of the sealing material 54 that protrudes outward from the protruding frame portion 53 (burr-like portion removing step S30, (b) and (c) of FIG. 7). In the burr-like portion removing step S30, the burr-like portions 53b and the sealing material 54 are removed so that the protruding lengths of the burr-like portions 53b and the sealing material 54 after removal are, for example, 0.3 mm or less. The protruding lengths may be the lengths of the burr-like portions 53b and the sealing material 54 along the Z-axis direction that protrude outward from the end face of the protruding frame portion in the Z-axis direction. In one example of the burr-like portion removing step S30, the removal device 100 is used to process the burr-like portions 53b and the sealing material 54 so that they are flush with the protruding frame portion 53.

[0062] 8 is a schematic diagram showing a removal device. The removal device 100 includes a fixing unit 110, a linear motion guide unit 120, and a cutting unit 130. The fixing unit 110 fixes the module main body 1A sealed with the sealing material 54 and positions the module main body 1A. One example of the fixing unit 110 is composed of a pair of restraint plates 111a and 111b that restrain the module main body 1A in the Z-axis direction. The restraint plates 111a and 111b are, for example, rectangular plates and restrain the electrode stack 10 of the module main body 1A in the Z-axis direction.

[0063] The linear motion guide unit 120 is fixed to the fixed unit 110. The linear motion guide unit 120 has a support unit 121 fixed to the restraint plate 111a, a rail 123 supported by the support unit 121, and a carriage 125 that moves along the rail 123. The support unit 121 is plate-shaped and extends along the X-axis direction. The rail 123 is a linear member and fixed to the support unit 121. The rail 123 extends along the X-axis direction of the module main body 1A that is restrained by the fixed unit 110. The carriage 125 engages with the rail 123 and moves along the rail 123 in the X-axis direction. The cutting unit 130 is fixed to the carriage 125 and moves together with the carriage 125 in the X-axis direction.

[0064] The cutting unit 130 includes a support portion 131, a roller 133 attached to the support portion 131, and a cutting blade 135 attached to the support portion 131. The support portion 131 is fixed to the carriage 125 and is disposed so as to overlap at least the burr-like portion 53b and the sealing material 54 in the Y-axis direction. The position of the support portion 131 relative to the carriage 125 in the Z-axis direction may be arbitrarily adjusted. The roller 133 has a rotation axis along the Y-axis direction and protrudes from the support portion 131 toward the module main body 1A in the Z-axis direction. The cutting blade 135 protrudes from the support portion 131 toward the module main body 1A in the Z-axis direction. In the Z-axis direction, the position of the tip of the cutting blade 135 is adjusted to be the same as the position of the protruding end of the roller 133 (i.e., the position where the roller 133 abuts against the module main body 1A) or to be within 0.3 mm of that position toward the support portion 131. The cutting blade 135, in one example, cuts an object when moved from the negative side to the positive side in the X-axis direction.

[0065] In the burr-like portion removing step S30, first, the module main body 1A is restrained by the restraint plates 111a and 111b. At this stage, the position of the cutting blade 135 in the X-axis direction may be the position of the edge of the liquid pouring frame 50 on the negative side in the X-axis direction. Next, the position of the support part 131 in the Z-axis direction relative to the carriage 125 is adjusted so that the roller 133 abuts against the liquid pouring frame 50 of the module main body 1A. Then, with the roller 133 still abutting against the liquid pouring frame 50, the carriage 125 supporting the cutting part 130 is moved on the rail toward the positive side in the X-axis direction. As a result, the cutting blade 135 provided on the cutting part 130 cuts, along the X-axis direction, the burr-like portion 53b formed on the outer periphery of one end of the protruding frame part 53 in the Z-axis direction and the excess sealing material 54. In the burr-like portion removing step S30, the burr-like portion 53b formed on the outer periphery of the other end of the protruding frame part 53 in the Z-axis direction is also removed. In one example, the constraint on the module main body 1A by the constraint plates 111a and 111b is temporarily released, the module main body 1A is turned over, and then it is again constrained by the constraint plates 111a and 111b, and the burr-like portion 53b formed on the outer peripheral edge of the other end of the protruding frame portion 53 in the Z-axis direction is cut off by the cutting blade 135.

[0066] FIG. 9 is a perspective view schematically illustrating an exterior pack of a power storage device. In FIG. 9, the power storage device 1 and an exterior pack 90 that covers the power storage device 1 are shown disassembled from each other. As shown in FIG. 9, the power storage device 1, with the connector unit 30 attached, is housed in the exterior pack 90 together with a cover member 60. The cover member 60, in the example, is housed in the exterior pack 90 together with the module main body 1A and the connector unit 30, with the cover member 60 being disposed between the outer surface 20s of the module main body 1A and the exterior film 93. That is, the cover member 60 is interposed between the outer surface 20s and the exterior film 93. In the example power storage device 1, the cover member 60 is composed of a first cover member 61 and a second cover member 62 that are disposed between the outer surface 20sA of the module main body 1A and the exterior film 93, and a third cover member 63 that is disposed between the outer surface 20sB of the module main body 1A and the exterior film 93. The first cover member 61 is disposed on the outer surface 20sA on the negative side (second side) in the X-axis direction of the terminal portion 58. The connector unit 30 is disposed between the first cover member 61 and the second cover member 62 in the X-axis direction, and is electrically connected to the terminal portion 58.

[0067] The exterior pack 90 accommodates the power storage device 1, the cover member 60, and the connector unit 30. An example of the exterior pack 90 includes a conductive member 91 and an exterior film 93 (film material). The conductive member 91 is composed of a first conductive member 91A and a second conductive member 91B, each of which has a rectangular sheet shape. The first conductive member 91A abuts against the second surface 15b of the current collector 15 of the positive terminal electrode 12 and is electrically connected to the positive terminal electrode 12. The second conductive member 91B abuts against the first surface 15a of the current collector 15 of the negative terminal electrode 13 and is electrically connected to the negative terminal electrode 13. The conductive member 91 may be, for example, a metal foil, such as an aluminum foil. The planar size of the conductive member 91 may be equal to or smaller than that of the current collector 15.

[0068] An example exterior film 93 is composed of a first exterior film 93A connected to the first conductive member 91A and a second exterior film 93B connected to the second conductive member 91B. The exterior film 93 may be, for example, a laminate film including a metal layer. The exterior film 93 has a rectangular frame shape. For example, the exterior film 93 may be formed by welding four strip-shaped sheets 94 along each of the four sides of the rectangle.

[0069] The inner edge of the rectangular frame-shaped exterior film 93 is located inside the peripheral edge of the conductive member 91 when viewed from the Z-axis direction. The inner edge of the exterior film 93 and the peripheral edge of the conductive member 91 are joined together while overlapping each other. In one example, the inner edge of the exterior film 93 and the peripheral edge of the conductive member 91 may be joined together with a resin material 95. The resin material 95 may be a rectangular frame-shaped sealing resin formed in a sheet. For example, the inner edge of the rectangular frame-shaped resin material 95 may be located inside the inner edge of the exterior film 93, and the outer edge of the resin material 95 may coincide with the peripheral edge of the conductive member 91. In the illustrated example, the first exterior film 93A is deformed so that its outer edge is located closer to the second exterior film 93B than its inner edge. The second exterior film 93B is deformed so that its outer edge is located closer to the first exterior film 93A than its inner edge.

[0070] The outer edge of the exterior film 93 is located outside the periphery of the contents when viewed from the Z-axis direction. The outer edge of the first exterior film 93A and the outer edge of the second exterior film 93B are joined to each other. As an example, the outer edge of the first exterior film 93A and the outer edge of the second exterior film 93B may be welded to each other. The periphery of the conductive member 91 and the inner edge of the exterior film 93 are sealed to each other, and the outer edge of the first exterior film 93A and the outer edge of the second exterior film 93B are joined to each other, thereby forming a sealed space inside the exterior pack 90. ​​After the module main body 1A and the like are housed in the exterior pack 90, the interior of the exterior pack 90 may be sealed in a reduced-pressure state.

[0071] The energy storage devices 1 sealed in the exterior pack 90 may be housed in a hard case made of metal or the like, for example, in a state where multiple energy storage devices 1 are stacked in the Z-axis direction. In this case, the multiple energy storage devices 1 may be electrically connected to each other by placing a conductive plate between the energy storage devices 1 adjacent to each other in the Z-axis direction. Furthermore, the positions of the liquid injection frames 50 of the multiple stacked energy storage devices 1 may be aligned so that the connector units 30 face the same direction.

[0072] As described above, the manufacturing method of the example energy storage device 1 includes the steps of: preparing a module main body 1A including an electrode stack 10 including a plurality of electrodes stacked in the Z-axis direction; a sealing main body 20 that seals the side surface of the electrode stack 10 along the Z-axis direction and has communication holes 27 that communicate with the internal space S of the electrode stack 10; and a protruding frame portion 53 that surrounds the communication holes 27 when viewed from the Y-axis direction and protrudes further in the Y-axis direction than the sealing main body 20; pressing a sealing material 54 abutting against the tip of the protruding frame portion 53 toward the base end of the protruding frame portion 53 with a hot plate 81a to melt the tip of the protruding frame portion 53 and form a burr-like portion 53b, and partially melting the tip of the protruding frame portion 53 and the sealing material 54 to seal the protruding frame portion 53; and removing the burr-like portion 53b formed at the tip of the protruding frame portion 53, at least the burr-like portion 53b formed on the outer periphery along the X-axis direction.

[0073] In the manufacturing method for the electricity storage device described above, the tip of the protruding frame portion 53 melted by the hot plate 81a and the sealing material 54 become compatible with each other, and the protruding frame portion 53 is sealed by the sealing material 54. At this time, the sealing material 54 abutting against the tip of the protruding frame portion 53 is pressed toward the base end of the protruding frame portion 53 by the hot plate 81a, so that the sealing material 54 is reliably bonded to the protruding frame portion 53. As the sealing material 54 is pressed by the hot plate 81a, a burr-like portion 53b is formed at the tip of the protruding frame portion 53. However, by removing the burr-like portion 53b formed on the outer periphery of the protruding frame portion 53, even if the electricity storage device 1 is packaged in an exterior film 93, damage to the exterior film 93 by the burr-like portion 53b is suppressed.

[0074] Furthermore, when a plurality of energy storage devices 1 are stacked in the Z-axis direction and housed in a hard case, the burr-like portions 53b of adjacent energy storage devices 1 in the Z-axis direction are prevented from interfering with each other. This allows the thickness of the conductive plate disposed between the energy storage devices 1 to be reduced. This also contributes to the miniaturization of the case.

[0075] In one example, in the step of removing the burrs 53b, the burrs 53b may be removed by a cutting blade 135 that moves along the X-axis direction using an end face of the module body 1A that intersects with the Z-axis direction as a reference height. With this configuration, the burrs 53b formed on the outer peripheral edge of the protruding frame portion 53 along the X-axis direction can be easily removed.

[0076] An energy storage device 1 according to one aspect of the present disclosure includes an electrode stack 10 including a plurality of electrodes stacked in the Z-axis direction, a sealing main body 20 that seals a side surface of the electrode stack 10 along the Z-axis direction and has communication holes 27 that communicate with an internal space S of the electrode stack 10, a protruding frame 53 that surrounds the communication holes 27 when viewed from the Y-axis direction and protrudes in the Y-axis direction beyond the sealing main body 20, and a sealing material 54 that seals a tip of the protruding frame 53. The tip of the protruding frame 53 has a burr-like portion 53b joined to the sealing material 54 at its inner peripheral edge, and does not have a burr-like portion 53b at least at a position along the X-axis direction of its outer peripheral edge.

[0077] In the above-described energy storage device 1, since no burr-like portions 53b are formed on the outer peripheral edge of the protruding frame portion 53, even if the energy storage device 1 is packaged in an exterior film 93, damage to the exterior film 93 by the burr-like portions 53b is suppressed. Moreover, since the inner peripheral edge of the protruding frame portion 53 has burr-like portions 53b joined to the sealing material 54, the sealing material 54 can be more firmly joined to the protruding frame portion 53. Furthermore, since the area of ​​the sealing material 54 exposed toward the internal space S is reduced, the amount of gas and the like permeating through the sealing material 54 is reduced.

[0078] Although examples of the embodiments of the present disclosure have been described above with reference to the drawings, the present disclosure is not limited to the above embodiments.

[0079] For example, the hot plate 81a may be provided with a cooling mechanism for cooling the contact surface 81b. As an example, a flow path through which a cooling refrigerant flows may be formed inside the hot plate 81a, so that the contact surface 81b heated by the heat source can be cooled by the refrigerant. In this case, after the sealing material is welded, the hot plate 81a is cooled and then returns to the standby position, thereby suppressing deformation of the sealing material.

[0080] Although the example in which the burr-like portion is removed by cutting has been shown, the burr-like portion may be removed by other methods. For example, the burr-like portion may be pressed toward the pouring frame by a hot plate that moves in the Z-axis direction. In this case, the burr-like portion is removed by being crushed by the hot plate.

[0081] In the example removal device 100, the linear motion guide portion 120 and the cutting portion 130 are provided on only one of the restraint plates 111a, but the linear motion guide portion 120 and the cutting portion 130 may be provided on both of the restraint plates 111a, 111b. [Explanation of symbols]

[0082] 1...energy storage device, 1A...module body, 10...electrode laminate (laminate), 11...bipolar electrode (electrode), 12...positive terminal electrode (electrode), 13...negative terminal electrode (electrode), 20...sealing body, 27...communicating hole, 29...sealing body, 50...filling frame, 53...protruding frame portion (frame portion), 54...sealing material, 81a...heating plate (heating element), S...internal space.

Claims

1. a step of preparing a module body including: a laminate including a plurality of electrodes laminated in a first direction; a sealing body portion that seals a side surface of the laminate along the first direction and has a communication hole that communicates with an internal space of the laminate; and a frame portion that surrounds the communication hole when viewed from a second direction intersecting the first direction and protrudes in the second direction beyond the sealing body portion; a step of pressing the sealing material abutting against the tip of the frame portion toward the base end of the frame portion using a heating body to melt the tip of the frame portion to form a burr-like portion and partially melt the tip of the frame portion and the sealing material to seal the frame portion; and removing burr-like portions formed on the outer peripheral edge of the frame portion along at least a third direction intersecting the first direction and the second direction from among the burr-like portions formed on the tip of the frame portion.

2. 2. The method for manufacturing an energy storage device according to claim 1, wherein the step of removing the burr-like portion removes the burr-like portion with a cutting blade that moves along a third direction that intersects with the first direction and the second direction, using an end face of the module body that intersects with the first direction as a reference height position.

3. a stack including a plurality of electrodes stacked in a first direction; a sealing body that seals a side surface of the stack body along the first direction and has a communication hole that communicates with an internal space of the stack body; a frame portion that surrounds the communication hole when viewed from a second direction intersecting the first direction and that protrudes in the second direction beyond the sealing main body portion; a sealing material that seals the tip of the frame portion, The tip of the frame portion has a burr-like portion joined to the sealing material at its inner peripheral edge, and does not have the burr-like portion at least at a position on the outer peripheral edge along a third direction that intersects the first direction and the second direction.

Images