Stacked battery

Abstract

The present invention is provided with: a laminated electrode body including a plurality of electrodes laminated in a lamination direction; and an exterior body that accommodates the laminated electrode body, the exterior body including: a first conductive plate (18) provided on one surface of the laminated electrode body in the lamination direction; a second conductive plate provided on the other surface of the laminated electrode body in the lamination direction; a first laminated sheet part joined to the peripheral edge of the first conductive plate; and a second laminated sheet part joined to the peripheral edge of the second conductive plate, the first laminated sheet part and the second laminated sheet part respectively include one or more first sheets (31) and one or more second sheets (32), and the one or more first sheets (31) and the one or more second sheets (32) cooperatively cover the peripheral edge of the first conductive plate (18) and the peripheral edge of the second conductive plate in a state in which a part of the second sheets (32) overlaps a part of the first sheets (31).

Description

Technical Field

[0001] The present disclosure relates to a stacked battery. Background Art

[0002] As a conventional laminated battery, Japanese Patent Application Laid-Open No. 2004-134210 (Patent Document 1) discloses a structure in which a laminated electrode assembly formed by stacking bipolar electrodes is sealed with a laminate sheet having an opening in the center in order to extract current from the uppermost and lowermost layers.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2004-134210 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] As described in Patent Document 1, when using a laminated sheet with an opening in the center, the manufacturing process becomes complicated because the center is cut out from a rectangular sheet. In addition, the laminated sheet in the center is wasted, resulting in an increase in manufacturing cost.

[0008] The present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to provide a stacked battery that can extract current from both ends of the electrodes in the stacking direction and can reduce manufacturing costs.

[0009] Solutions for solving problems

[0010] The stacked battery disclosed herein comprises: a stacked electrode body comprising a plurality of electrodes stacked in a stacking direction; and an outer casing housing the stacked electrode body. The outer casing comprises: a first conductive plate disposed on one surface of the stacked electrode body in the stacking direction; a second conductive plate disposed on the other surface of the stacked electrode body in the stacking direction; a first laminated sheet portion bonded to the periphery of the first conductive plate; and a second laminated sheet portion bonded to the periphery of the second conductive plate. The first laminated sheet portion and the second laminated sheet portion respectively comprise one or more first sheets and one or more second sheets. The one or more first sheets and the one or more second sheets cooperatively cover the periphery of the first conductive plate and the periphery of the second conductive plate in a state in which a portion of the second sheet overlaps a portion of the first sheet.

[0011] According to the above structure, a first conductive plate is provided on one surface of the electrode stack in the stacking direction, and a second conductive plate is provided on the other surface of the electrode stack in the stacking direction. Therefore, current can be extracted from both sides of the stacking direction via the first and second conductive plates. Furthermore, the pre-cut first and second sheets are spliced ​​and joined to the peripheries of the first and second conductive plates, with a portion of the second sheet overlapping a portion of the first sheet, so as to cooperatively cover the peripheries of the first and second conductive plates. Therefore, when forming the outer body, there is no need to cut the center portion from the rectangular laminated sheet, which can reduce the loss of the laminated sheet and suppress manufacturing costs.

[0012] In the above-mentioned stacked battery based on the present disclosure, the above-mentioned first sheet may also have a first metal layer and a sealant resin layer provided on both sides of the above-mentioned first metal layer. The above-mentioned second sheet may also have: a second metal layer having a first main surface and a second main surface; and a first resin layer provided on the side of the above-mentioned first main surface. The above-mentioned first resin layer may also be compatible with the above-mentioned sealant resin layer. The above-mentioned one or more first sheets and the above-mentioned one or more second sheets may also cooperatively cover the above-mentioned periphery of the above-mentioned first conductive plate and the above-mentioned periphery of the above-mentioned second conductive plate in a state in which a part of the above-mentioned first resin layer overlaps a part of the above-mentioned sealant resin layer. The above-mentioned sealant resin layer of the above-mentioned first sheet and the above-mentioned first resin layer of the above-mentioned second sheet may also be compatible.

[0013] According to the above configuration, the sealing performance of the exterior body can be improved by being compatible with the first resin layer overlapping a portion of the sealant resin layer.

[0014] In the above-mentioned stacked battery based on the present disclosure, the side surfaces of the above-mentioned stacked electrode body may also be sealed by a sealing body. When observed from the above-mentioned stacking direction, the above-mentioned first conductive plate and the above-mentioned second conductive plate may each have a plurality of corner portions. At least one of the above-mentioned first laminated sheet portion and the above-mentioned second laminated sheet portion may also have an embossed portion for accommodating the above-mentioned stacked electrode body and the above-mentioned sealing body. The above-mentioned multiple second sheets may also be arranged in a manner covering the above-mentioned multiple corner portions. The above-mentioned second sheet may also have a second resin layer provided on the side of the above-mentioned second main surface. The above-mentioned second resin layer may also be a high-strength resin layer relative to the above-mentioned sealant resin layer or the above-mentioned first resin layer. The corners of the above-mentioned embossed portion may also be formed on the above-mentioned second sheet.

[0015] According to the above configuration, in the second sheet having the embossed corners, a second resin layer having a higher strength than the sealant layer of the first sheet and the first resin layer provided on the first main surface is provided on the second main surface. Therefore, when the first laminated sheet and the second laminated sheet are embossed, damage to the first laminated sheet and the second laminated sheet (specifically, the second sheet) at the locations corresponding to the corners can be further suppressed.

[0016] In the stacked battery according to the present disclosure, a resin layer compatible with the sealant resin layer and the first resin layer may be disposed between the one or more first sheets and the one or more second sheets and the periphery of the first conductive plate and the periphery of the second conductive plate. Alternatively, the one or more first sheets and the one or more second sheets may each have an inner end portion on the side where the periphery of the first conductive plate and the periphery of the second conductive plate are located. When viewed in the stacking direction, the inner edge of the resin layer may be located closer to the center of the stacked electrode body than the inner end portion.

[0017] According to the above structure, even if the first conductive plate and the second conductive plate cannot ensure a sufficient surface distance from the first metal layer or the second metal layer, the insulation between the first conductive plate and the second conductive plate and the first metal layer or the second metal layer can be ensured by the resin layer.

[0018] In the stacked battery according to the present disclosure, the stacked electrode body may include a positive terminal electrode located on one side of the stacking direction and a negative terminal electrode located on the other side of the stacking direction. The positive terminal electrode may include a current collector plate having a first surface on the one side of the stacking direction. The negative terminal electrode may include a current collector plate having a second surface on the other side of the stacking direction. The first conductive plate may be electrically connected to the positive terminal electrode by being arranged in contact with the first surface. The second conductive plate may be electrically connected to the negative terminal electrode by being arranged in contact with the second surface.

[0019] Generally, when the first and second laminated sheets are directly joined to a laminated electrode body (specifically, the current collector plates of the positive and negative end electrodes), if a joining failure occurs, the laminated electrode body is discarded together with the laminated electrode body.

[0020] According to the above structure, the first and second conductive plates are formed of a different member from the current collector plates of the positive and negative terminal electrodes. Therefore, if a poor connection occurs when the first and second laminated sheets are joined to the first and second conductive plates, the stacked electrode assembly does not need to be discarded.

[0021] In the stacked battery based on the present disclosure, the first conductive plate and the second conductive plate may each have a rectangular shape, the rectangular shape including a pair of first sides facing each other in a first direction and a pair of second sides facing each other in a second direction perpendicular to the first direction. Alternatively, in each of the first conductive plate and the second conductive plate, the first piece may be arranged along the first side between the pair of second sides on one side and the other side of the first direction. Alternatively, in each of the first conductive plate and the second conductive plate, the second piece may be arranged along the second side on one side and the other side of the second direction in a manner covering corners of the first conductive plate and the second conductive plate located on both sides of the first direction.

[0022] According to the above structure, by arranging the first sheet along a pair of first sides and the second sheet along a pair of second sides, the periphery of the first and second conductive plates can be efficiently surrounded by four sheets. Therefore, compared with a structure in which the center portion is cut from a rectangular laminate sheet when forming the outer body, the loss of the laminate sheet can be further reduced.

[0023] In the laminated battery according to the present disclosure, the first sheet may include a first metal layer extending in the second direction. Both end surfaces of the first metal layer in the second direction may be covered with the resin layer.

[0024] According to the above configuration, since both end faces of the first metal layer are covered with the resin layer, short circuits via the both end faces of the first metal layer can be suppressed.

[0025] In the stacked battery based on the present disclosure, the first conductive plate and the second conductive plate may each have a rectangular shape, the rectangular shape including a pair of first sides facing each other in a first direction and a pair of second sides facing each other in a second direction perpendicular to the first direction. Alternatively, in each of the first conductive plate and the second conductive plate, the first piece may be arranged so as to protrude outward from the plurality of corners in the first direction. Alternatively, the plurality of second pieces may include a pair of first side pieces arranged along the pair of first sides and a pair of second side pieces arranged along the pair of second sides in each of the first conductive plate and the second conductive plate.

[0026] According to the above configuration, the area of ​​the first sheet can be reduced, and the peripheries of the first and second conductive plates can be surrounded by the plurality of first sheets and the plurality of second sheets.

[0027] Effects of the Invention

[0028] According to the present disclosure, it is possible to provide a laminated battery in which the formability of a laminate sheet is improved and the sealing performance is maintained well. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a perspective view of the laminated battery according to the first embodiment.

[0030] Figure 2 It is along Figure 1 A cross-sectional view along line II-II is shown.

[0031] Figure 3 It is along Figure 1 A cross-sectional view along line III-III is shown.

[0032] Figure 4 Is the magnification represented by Figure 3 A cross-sectional view of the second piece of the area surrounded by the two-dot chain line IV.

[0033] Figure 5 This is a diagram showing a step of disposing a resin layer on the periphery of the first conductive plate in the step of manufacturing the first laminated sheet portion of the first embodiment.

[0034] Figure 6 This is a diagram showing the step of arranging the first sheet in the step of manufacturing the first laminated sheet portion of the first embodiment.

[0035] Figure 7 This is a diagram showing the step of arranging the second sheet in the step of manufacturing the first laminated sheet portion of the first embodiment.

[0036] Figure 8 This is a diagram showing a step of disposing a resin layer on the periphery of the first conductive plate in the step of manufacturing the first laminated sheet portion of the second embodiment.

[0037] Figure 9 This is a diagram showing the step of arranging the first sheet in the process of manufacturing the first laminated sheet portion of the second embodiment.

[0038] Figure 10 This is a diagram showing the step of arranging the second sheet in the step of manufacturing the first laminated sheet portion of the second embodiment.

[0039] Figure 11 It is along Figure 10 A cross-sectional view taken along line XI-XI is shown.

[0040] Figure 12 This is a diagram showing the step of arranging the first sheet in the process of manufacturing the first laminated sheet portion of the third embodiment.

[0041] Figure 13 This is a diagram showing the step of arranging the second sheet in the step of manufacturing the first laminated sheet portion of the third embodiment.

[0042] Figure 14This is a diagram showing the step of arranging the first sheet in the process of manufacturing the first laminated sheet portion of the fourth embodiment.

[0043] Figure 15 This is a diagram showing the step of disposing the second sheet in the step of manufacturing the first laminated sheet portion of the fourth embodiment.

[0044] Figure 16 This is a cross-sectional view of a stacked battery according to the fifth embodiment.

[0045] Figure 17 Is the magnification represented by Figure 16 The cross-sectional view of the second sheet is shown in the area surrounded by XVII.

[0046] Figure 18 This is a cross-sectional view of a stacked battery according to the sixth embodiment. DETAILED DESCRIPTION

[0047] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. It should be noted that in the embodiments described below, identical or common parts are denoted by the same reference numerals in the drawings, and their description will not be repeated.

[0048] (Implementation Method 1)

[0049] Figure 1 This is a perspective view of the laminated battery according to the first embodiment. Figure 2 It is along Figure 1 A cross-sectional view along line II-II is shown. Figure 3 It is along Figure 1 The cross-sectional view of the III-III line is shown. Figures 1 to 3 , the stacked battery 100 according to the first embodiment will be described.

[0050] like Figures 1 to 3 As shown, the laminated battery 100 of Embodiment 1 includes: a storage battery module 1 having a laminated electrode body 10 formed by stacking a plurality of electrodes (electrode plates 11) in a stacking direction, described later, and a resin sealant 40; and an exterior body 20 that houses the storage battery module 1. The exterior body 20 is electrically connected to the terminal electrodes of the laminated electrode body 10, described later, and is configured to allow current to be extracted externally in the stacking direction. The exterior body 20 includes a first conductive plate 18, a second conductive plate 19, a first laminate sheet 21, a second laminate sheet 22, and a resin layer 50. The laminated battery 100 is, for example, a secondary battery such as a lithium-ion battery.

[0051] The stacked electrode body 10 includes a plurality of electrode plates 11, a plurality of separators 15, a positive terminal electrode 16, and a negative terminal electrode 17. The plurality of electrode plates 11, the positive terminal electrode 16, and the negative terminal electrode 17 are stacked in a stacking direction with separators 15 interposed therebetween.

[0052] Separator 15 is formed into a sheet. Examples of separator 15 include porous films made of polyolefin resins such as polyethylene (PE) and polypropylene (PP), and woven or nonwoven fabrics made of polypropylene, methylcellulose, and the like. Separator 15 may also be reinforced with a vinylidene fluoride resin compound.

[0053] A plurality of electrode plates 11 are provided between a positive terminal electrode 16 and a negative terminal electrode 17 . The electrode plates 11 are, for example, bipolar electrodes and include a current collector 12 , a positive electrode layer 13 , and a negative electrode layer 14 .

[0054] The current collector 12 may include, for example, at least one selected from the group consisting of aluminum (Al), stainless steel, nickel (Ni), chromium (Cr), platinum (Pt), niobium (Nb), iron (Fe), titanium (Ti), and zinc (Zn). Alternatively, the current collector 12 may be formed by plating the surface of a metal foil.

[0055] The current collector 12 has a first surface 12a located on one side in the stacking direction and a second surface 12b located on the other side in the stacking direction. A negative electrode layer 14 is provided on the first surface 12a. A positive electrode layer 13 is provided on the second surface 12b.

[0056] The positive terminal electrode 16 is located on one side in the stacking direction. It includes the current collector 12 and the positive electrode layer 13. Specifically, in the positive terminal electrode 16, the negative electrode layer 14 and the positive electrode layer 13 are not provided on the first surface 12a of the current collector 12, and the positive electrode layer 13 is provided on the second surface 12b of the current collector 12. A first conductive plate 18 is disposed on the first surface 12a of the current collector 12 in the positive terminal electrode 16.

[0057] The negative terminal electrode 17 is located on the other side of the stacking direction. It includes the current collector 12 and the negative electrode layer 14. Specifically, the negative electrode layer 14 is provided on the first surface 12a of the current collector 12, while the negative electrode layer 14 and the positive electrode layer 13 are not provided on the second surface 12b of the current collector 12. A second conductive plate 19 is disposed on the second surface 12b of the current collector 12 in the negative terminal electrode 17.

[0058] The positive electrode layer 13 is formed by applying a positive electrode active material to the second surface 12b. As the positive electrode active material, for example, a substance that can occlude and release charge carriers such as lithium ions can be used. Specifically, as the positive electrode active material, a lithium ion composite metal oxide having a layered rock salt structure, a metal oxide having a spinel structure, a polyanion compound, or the like that can be used as a positive electrode active material for a lithium ion secondary battery can be used. In addition, two or more positive electrode active materials can be used in combination. For example, the positive electrode active material can also include olivine-type lithium iron phosphate (LiFePO4).

[0059] The negative electrode layer 14 is formed by applying a negative electrode active material to the first surface 12a. Examples of the negative electrode active material include lithium, carbon, metal compounds, and elements capable of alloying with lithium or compounds thereof.

[0060] Note that, in any of the electrode plates 11 , the negative electrode end electrode 17 , and the positive electrode end electrode 16 , the peripheral portion of the current collector 12 is an uncoated region where the positive electrode layer 13 and the negative electrode layer 14 are not provided.

[0061] The resin seal 40 is provided to seal the periphery of the stacked electrode assembly 10. Specifically, the resin seal 40 seals the internal space formed between two adjacent electrode plates 11. An electrolyte is injected into this internal space. The resin seal 40 is formed by curing a resin member such as a hot melt member, a thermoplastic resin, a thermosetting resin, or a light-curing resin. The resin seal 40 is provided in the uncoated area.

[0062] The first conductive plate 18 and the second conductive plate 19 are arranged so as to sandwich the stacked electrode body 10 in the stacking direction. Specifically, the first conductive plate 18 is arranged on the first surface 12a of the current collector 12 included in the above-mentioned positive terminal electrode 16. The first conductive plate 18 is electrically connected to the positive terminal electrode 16 by being arranged in contact with the first surface 12a. The first conductive plate 18 functions as the positive terminal of the stacked battery 100 by being electrically connected to the positive terminal electrode 16. The second conductive plate 19 is arranged on the second surface 12b of the current collector 12 included in the above-mentioned negative terminal electrode 17. The second conductive plate 19 is electrically connected to the negative terminal electrode 17 by being arranged in contact with the second surface 12b. The second conductive plate 19 functions as the negative terminal of the stacked battery 100 by being electrically connected to the negative terminal electrode 17. In the stacked battery 100 , current can be drawn from the internally housed power storage module 1 to the outside via the first conductive plate 18 functioning as a positive electrode terminal and the second conductive plate 19 functioning as a negative electrode terminal, without using a tab for drawing current to the outside.

[0063] The first conductive plate 18 and the second conductive plate 19 have a rectangular shape with a plurality of corners. The peripheries of the first conductive plate 18 and the second conductive plate 19 are positioned on the resin sealant 40 .

[0064] The first conductive plate 18 and the second conductive plate 19 may be made of at least one selected from the group consisting of aluminum (Al), stainless steel, nickel (Ni), chromium (Cr), platinum (Pt), niobium (Nb), iron (Fe), titanium (Ti), and zinc (Zn). Alternatively, the first conductive plate 18 and the second conductive plate 19 may be made of a metal foil having a plated surface.

[0065] The first laminated sheet portion 21 is bonded to the periphery of the first conductive plate 18. In this embodiment, the first laminated sheet portion 21 is bonded to the first conductive plate 18 with a resin layer 50 interposed between the first laminated sheet portion 21 and the periphery of the first conductive plate 18. The second laminated sheet portion 22 is bonded to the periphery of the second conductive plate 19. In this embodiment, the second laminated sheet portion 22 is bonded to the second conductive plate 19 with a resin layer 50 interposed between the second laminated sheet portion 22 and the periphery of the second conductive plate 19.

[0066] The resin layer 50 may also be made of an insulating resin material. The resin layer 50 may also be made of a resin material that can be welded to the first conductive plate 18 and the second conductive plate 19. As the resin layer 50, for example, a heat-melting resin such as polyethylene, polypropylene, modified polyethylene, or modified polypropylene may be used. The resin layer 50 may be a single-layer structure formed by the above-mentioned resin, or a multi-layer structure formed by stacking a plurality of the above-mentioned resins. When the resin layer 50 is set as a multi-layer structure, the surface facing the first conductive plate 18 and the second conductive plate 19 may be appropriately made of modified polyethylene or modified polypropylene that has higher adhesion to metal than polyethylene or polypropylene. The resin layer 50 has the function of preventing short circuits between the first conductive plate 18, the second conductive plate 19 and the first metal layer 310 and the second metal layer 320 included in the first sheet 31 and the second sheet 32.

[0067] The central portions of the first conductive plate 18 and the second conductive plate 19 are exposed areas not covered by the resin layer 50, the first laminate sheet 21, and the second laminate sheet 22. Current can be directly extracted from the stored power storage module 1 to the outside through these exposed areas.

[0068] The first laminated sheet portion 21 includes a plurality of first sheets 31 and a plurality of second sheets 32. The plurality of first sheets 31 and the plurality of second sheets 32 cooperate to cover the periphery of the first conductive plate 18. The second laminated sheet portion 22 includes a plurality of first sheets 31 and a plurality of second sheets 32. The plurality of first sheets 31 and the plurality of second sheets 32 cooperate to cover the periphery of the second conductive plate 19.

[0069] The first sheet 31 includes a first metal layer 310 and sealant resin layers 311 and 312. The first metal layer 310 has a sheet shape. For example, a metal foil such as Al foil, Ni foil, Cu foil, or stainless steel foil can be used for the first metal layer 310. The first metal layer 310 imparts moisture permeability, air permeability, and chemical resistance to the first sheet 31. The thickness of the first metal layer 310 can be, for example, approximately 40 μm to 80 μm. Increasing the thickness of the first metal layer 310 improves formability during embossing, which will be described later.

[0070] The sealant resin layers 311 and 312 are provided on both surfaces of the first metal layer 310 . Specifically, the sealant resin layer 311 is provided on the inner surface of the first metal layer 310 , and the sealant resin layer 312 is provided on the outer surface of the first metal layer 310 .

[0071] The sealant resin layers 311 and 312 are compatible with the resin layer 50. As the resin layer 50 and the sealant resin layers 311 and 312, for example, heat-fusible resins such as polyethylene, polypropylene, modified polyethylene, and modified polypropylene can be used. The sealant resin layers 311 and 312 can be formed of a single layer or a multi-layer structure. The sealant resin layers 311 and 312 function as a sealing layer of the outer body 20. In addition, the sealant resin layers 311 and 312 also have the function of an insulating layer, which insulates the first laminated sheet 21 and the second laminated sheet 22 when the first laminated sheet 21 and the second laminated sheet 22 are bonded. It should be noted that the thickness of the first sealant resin layer 311 can also be equal to the thickness of the second sealant resin layer 312. For example, the thickness of the first sealant resin layer 311 and the thickness of the second sealant resin layer 312 can be set to about 80 μm. Furthermore, because resin layer 50 is provided inside first sealant resin layer 311 to prevent short circuits with first conductive plate 18 and second conductive plate 19, the thickness of first sealant resin layer 311 can be made thinner than that of second sealant resin layer 312. In this case, for example, first sealant resin layer 311 only needs to be thick enough to be welded to resin layer 50, and can be less than half the thickness of second sealant resin layer 312. Specifically, for example, the thickness of first sealant resin layer 311 can be set to approximately 30 μm, and the thickness of second sealant resin layer 312 can be set to approximately 70 μm. By making the thickness of first sealant resin layer 311 thinner than that of second sealant resin layer 312, the amount of resin contained in first sheet 31 can be reduced, thereby lowering the manufacturing cost of the stacked battery.

[0072] Figure 4 Is the magnification represented by Figure 3 A cross-sectional view of the second piece of the area surrounded by the double-dotted line IV. Figure 3 and Figure 4As shown, the second sheet 32 ​​includes a second metal layer 320, a first resin layer 321, and a second resin layer 322. The second metal layer 320 has a sheet shape. It has a first principal surface 320a and a second principal surface 320b. The first principal surface 320a faces inward (the side where the stacked electrode body 10 is located), while the second principal surface 320b faces outward (the side opposite to the side where the stacked electrode body 10 is located). For example, metal foil such as Al foil, Ni foil, Cu foil, or stainless steel foil can be used for the second metal layer 320. The thickness of the second metal layer 320 can be thicker than that of the first metal layer 310 or the same as that of the first metal layer 310. The thickness of the second metal layer 320 can be, for example, approximately 60 to 80 μm. This thickness ensures sufficient pressure resistance and formability of the second sheet 32. Furthermore, by setting the thickness of the first metal layer 310 of the first sheet 31 to be approximately the same as the thickness of the second metal layer 320 (eg, approximately 80 μm), the pressure resistance and formability of the first sheet 31 can be sufficiently ensured.

[0073] The first resin layer 321 is provided on the first main surface 320a. The first resin layer 321 is compatible with the sealant resin layer 312. For example, a heat-fusible resin such as polyethylene, polypropylene, modified polyethylene, or modified polypropylene can be used as the first resin layer 321. The first resin layer 321 can be composed of a single layer of polyethylene, polypropylene, modified polyethylene, or modified polypropylene, or can be composed of a plurality of laminated resin layers. In this embodiment, the first resin layer 321 includes a polypropylene layer 33 and a modified polypropylene layer 34.

[0074] When the first resin layer 321 comprises multiple resin layers, a resin layer compatible with the sealant resin layer 312 is disposed on its outermost surface. Such a resin layer may be formed of the same resin material as the sealant resin layers 311 and 312. Furthermore, when multiple resin layers are provided, the thickness of each resin layer can be set to approximately the same. For example, the thickness of the polypropylene layer 33 disposed on the outermost surface may be set to approximately 30 μm, and the thickness of the modified polypropylene layer 34 disposed between the polypropylene layer and the second metal layer 320 may be set to approximately 30 μm.

[0075] The second resin layer 322 is provided on the second main surface 320b. The second resin layer 322 may also be a resin layer having higher strength than the sealant resin layer 312 or the first resin layer 321. In addition, the second resin layer 322 may also use a resin material that is incompatible with the sealant resin layer 312. As the second resin layer 322, for example, a single layer of polyethylene terephthalate or nylon, or a layer formed by laminating them can be used. In this embodiment, the second resin layer 322 includes a nylon layer 35 and a polyethylene terephthalate layer 36. The polyethylene terephthalate layer 36 is located at a position closer to the outer layer side than the nylon layer 35. In addition, the thickness of the polyethylene terephthalate layer 36 may also be smaller than the thickness of the nylon layer 35. For example, the thickness of the nylon layer 35 can be set to about 15 μm to about 25 μm, and the thickness of the polyethylene terephthalate layer 36 can be set to about 12 μm.

[0076] Here, the second resin layer 322 may be stronger than the sealant resin layer 312 or the first resin layer 321. This means that the second resin layer 322 has higher rigidity or tensile strength than the sealant resin layer 312 or the first resin layer 321. This effectively prevents damage to the second metal layer 320 when the second sheet 32 ​​is subjected to external forces such as puncture. Furthermore, by providing the second sheet 32 ​​with a second resin layer having higher strength than the sealant resin layer 312 or the first resin layer 321, the overall strength of the second sheet 32 ​​is increased, effectively preventing damage to the second sheet 32 ​​during deep drawing, as described later. Alternatively, the second resin layer 322 may be a laminated layer of a polypropylene layer and a nylon layer 35. In this case, the polypropylene layer is disposed as the outermost layer. The thickness of the polypropylene layer may be greater than that of the nylon layer 35. For example, the thickness of the nylon layer 35 may be approximately 25 μm, and the thickness of the polypropylene layer may be approximately 30 to 70 μm. It should be noted that the thickness of each resin layer constituting the second resin layer 322 may be set to be less than or equal to half the thickness of the second metal layer 320 .

[0077] The first laminated sheet 21 is deep-drawn into a substantially box-like shape while being bonded to the first conductive plate 18. Specifically, the first laminated sheet 21 has a box-like shape that is open downward. A flange 21f that is bent outward is provided at the open end of the first laminated sheet 21.

[0078] The second laminated sheet 22 is deep-drawn into a substantially box-like shape while being bonded to the second conductive plate 19. Specifically, the second laminated sheet 22 has an upwardly open box-like shape. A flange 22f bent outward is provided at the open end of the second laminated sheet 22.

[0079] In this way, the first laminated sheet portion 21 and the second laminated sheet portion 22 are provided with receiving recesses 21c and 22c on the inner side for receiving the stacked electrode body 10. The peripheral edge portion of the upper surface and the peripheral edge portion of the lower surface of the stacked electrode body 10 and the peripheral surface of the stacked electrode body 10 are covered by the receiving recesses 21c and 22c. In addition, the central portion of the upper surface of the stacked electrode body 10 is covered by the first conductive plate 18, and the central portion of the lower surface of the stacked electrode body 10 is covered by the second conductive plate 19. The receiving recesses 21c and 22c are composed of, for example, embossed portions formed by embossing the first laminated sheet portion 21 and the second laminated sheet portion 22. It should be noted that the receiving recesses 21c and 22c are not limited to embossed portions, and can be provided as long as they are capable of receiving the stacked electrode body 10. In addition, in the above, the case where the storage recess is provided in both the first laminate sheet portion 21 and the second laminate sheet portion 22 is exemplified, but the storage recess may be provided in only one of the first laminate sheet portion 21 and the second laminate sheet portion 22 .

[0080] The first sheet 31 has an inner end 31i located at the center of the laminated electrode body 10. The second sheet 32 ​​has an inner end 32i located at the center of the laminated electrode body 10. The resin layer 50 has an inner edge 50i and an outer edge 50c located at the center of the laminated electrode body 10.

[0081] In order to ensure the insulation distance between the first metal layer 310 of the first piece 31 and the second metal layer 320 of the second piece 32 and the first conductive plate 18 and the second conductive plate 19, the inner edge portion 50i is located closer to the center side of the stacked electrode body 10 than the inner end portions 31i and 32i.

[0082] The first conductive plate 18 has an outer edge portion 18c, and the second conductive plate 19 has an outer edge portion 19c. The inner end portions 31i and 32i are located closer to the center of the stacked electrode assembly 10 than the outer edges 18c and 19c.

[0083] The portions where the first conductive plate 18 and the second conductive plate 19 overlap with the resin layer 50 are welded, and the joint interface is sealed.

[0084] The outer edge portion 50c of the resin layer 50 is located outside the outer edges 18c and 19c, but the present invention is not limited thereto. The outer edge portion 50c and the outer edges 18c and 19c may be coplanar.

[0085] By bonding the first sheet 31 and the second sheet 32 ​​to the first conductive plate 18 and the second conductive plate 19 via the resin layer 50 , short circuiting of the first conductive plate 18 and the second conductive plate 19 via the first sheet 31 and the second sheet 32 ​​having the metal layer can be suppressed.

[0086] Figures 5 to 71 is a diagram showing a predetermined process of manufacturing the first laminated sheet portion 21 of the first embodiment. Figures 5 to 7 , the details of the first laminated sheet portion 21 will be described. It should be noted that the structure of the second laminated sheet portion 22 is substantially the same as that of the first laminated sheet portion 21, and therefore description thereof will be omitted.

[0087] Figure 5 This is a diagram showing a step of disposing a resin layer on the periphery of the first conductive plate in the process of manufacturing the first laminated sheet portion 21 according to the first embodiment.

[0088] like Figure 5 As shown, when manufacturing the first laminated sheet portion 21, first, the first conductive plate 18 and a plurality of resin layers 50 are prepared.

[0089] The first conductive plate 18 has a rectangular shape having corners at four corners. The first conductive plate 18 has a pair of first sides 181 and a pair of second sides 182 .

[0090] The pair of first side portions 181 face each other in the first direction (DR1 direction), and the pair of second side portions 182 face each other in the second direction (DR2 direction).

[0091] The multiple resin layers 50 each have a sheet shape. The multiple resin layers 50 are arranged along a pair of first sides 181 and a pair of second sides 182 to cover the periphery of the first conductive plate 18. The multiple resin layers 50 are arranged on one main surface of the first conductive plate 18. In this case, the multiple resin layers 50 may also be fixed to the one main surface of the first conductive plate 18 by welding, such as heat pressing.

[0092] Figure 6 This is a diagram showing a step of arranging the first sheet in the process of manufacturing the first laminated sheet unit 21 according to the first embodiment.

[0093] like Figure 6 As shown, the first piece 31 is arranged along the first side 181 between the pair of second side portions 182 on one side and the other side in the first direction. Specifically, the first piece 31A is arranged on one side in the first direction where the pair of first side portions 181 face each other, and the first piece 31B is arranged on the other side in the first direction where the pair of first side portions 181 face each other.

[0094] The first piece 31A and the first piece 31B have an inner end 31i and an outer end 31c. The inner end 31i is located closer to the center of the first conductive plate 18 than the outer end 31c.

[0095] The first sheet 31A and the first sheet 31B are arranged on the resin layer 50 so that the outer end 31c is located further outward from the resin layer 50. In this state, the inner edge 50i of the resin layer 50 is located closer to the center of the first conductive plate 18 than the inner end 31i. As described above, this ensures the insulation distance between the first conductive plate 18 and the first metal layer 310 included in the first sheets 31A and 31B.

[0096] The first sheets 31A and 31B are arranged so that the sealant resin layer 311 contacts the resin layer 50 and the sealant resin layer 312 is located on the side opposite to the resin layer 50. The first sheet 31 is also arranged on the second conductive plate 19 side in substantially the same manner as described above.

[0097] Figure 7 This is a diagram showing a step of arranging the second sheet 32 ​​in the step of manufacturing the first laminate sheet unit 21 according to the first embodiment.

[0098] like Figure 7 As shown, the second sheet 32 ​​is arranged along the second side 182 so as to cover the corners of the first conductive plate 18 located on both sides in the first direction on one side and the other side in the second direction.

[0099] The second sheet 32, with a portion of the first resin layer 321 overlapping the sealant resin layer 312 of the first sheet 31, cooperates with the first sheet 31 to cover the periphery of the first conductive plate 18. When viewed in the stacking direction, the second sheet 32 ​​overlaps the first sheet 31 at each corner of the first conductive plate 18. In the portion where the first and second sheets 31 and 32 do not overlap, the first side 181 is covered only by the first sheet 31, and in the portion where the first and second sheets 31 and 32 do not overlap, the second side 182 is covered only by the second sheet 32.

[0100] The second piece 32A is disposed on one side in the second direction where the pair of second sides 182 face each other, and the second piece 32B is disposed on the other side in the second direction. The second pieces 32A and 32B have one end 32a located on one side in the first direction where the pair of first sides 181 face each other, and another end 32b located on the other side in the first direction. The first pieces 31A and 31B have one end 31a located on one side in the second direction where the pair of second sides 182 face each other, and another end 31b located on the other side in the first direction.

[0101] The second sheets 32A and 32B are arranged on the resin layer 50 and the first sheets 31A and 31B so that their outer ends 32c are located further outward from the resin layer 50. In this state, the inner edge 50i of the resin layer 50 is located closer to the center of the first conductive plate 18 than the inner end 32i of the second sheet 32. This ensures an insulation distance between the first conductive plate 18 and the first metal layer 310 included in the second sheets 32A and 32B.

[0102] One end portion 32a and the other end portion 32b of the second sheet 32A overlap with one end portion 31a of the first sheet 31A and one end portion 31a of the first sheet 31B, respectively.

[0103] Similarly, one end 32a and the other end 32b of the second piece 32B overlap with the other end 31b of the first piece 31A and the other end 31b of the first piece 31B, respectively.

[0104] In this way, the first sheet 31 and the second sheet are spliced ​​together to cover the periphery of the first conductive plate 18 and the second conductive plate 19, but no gap is formed between the first conductive plate 18 and the second conductive plate 19 and the first metal layer 310 and the second metal layer 320, so that it is possible to appropriately suppress the infiltration of moisture, air, etc. into the interior of the outer body 20. That is, in the first laminated sheet composed of the first conductive plate 18, the first sheet 31 and the second sheet 32, and the second laminated sheet composed of the second conductive plate 19, the first sheet 31 and the second sheet 32, as shown in FIG. Figure 7 As shown, when viewed from the first direction, the metal layer exists in all parts.

[0105] With the resin layer 50, the plurality of first sheets 31, and the plurality of second sheets 32 arranged, their overlapping portions are heated and pressed (hot pressing) using a heater or the like, thereby thermally fusing the mutually compatible resin layer 50, the sealant resin layers 311 and 312, and the first resin layer 321. As a result, the plurality of first sheets 31 and the second sheets 32 are fixed to the first conductive plate 18 via the resin layer 50.

[0106] It should be noted that, while the above description illustrates a case where multiple first sheets 31 and second sheets 32 are simultaneously fixed to the first conductive plate 18, the present invention is not limited thereto. Alternatively, with the first sheet 31 disposed on the resin layer 50, the first sheet 31 may be first welded and fixed to the resin layer 50 by heat pressing or the like. Subsequently, the second sheet 32 ​​may be disposed on the first sheet 31 and the resin layer 50, and then welded and fixed to the resin layer 50 and the first sheet 31 by heat pressing or the like. In this manner, multiple first sheets 31 and multiple second sheets 32 may be sequentially fixed to the first conductive plate 18.

[0107] The first sheets 31 and the second sheets 32 are fixed to the first conductive plate 18 via the resin layer 50, thereby forming a first laminated sheet. The first laminated sheet is subjected to deep drawing. Thus, the first sheets 31, the second sheets 32 and the first conductive plate 18 are embossed into a roughly box shape to form an upper shell. It should be noted that in the case of deep drawing, Figure 7 The area surrounded by the processing line 90 indicated by the two-dot chain line in FIG. 3 is punched out with a punch, thereby forming the corner portion of the embossed portion in the second sheet 32 ​​.

[0108] On the side of the second conductive plate 19, a plurality of first sheets 31 and second sheets 32 are fixed to the second conductive plate 19 via a resin layer 50 in a structure roughly similar to that on the side of the first conductive plate 18, thereby forming a second laminated sheet. The second laminated sheet is deep-drawn. More specifically, the plurality of first sheets 31 and second sheets 32 that surround the portion of the second conductive plate 19 in a frame shape are deep-drawn. As a result, the plurality of first sheets 31, second sheets 32, and second conductive plate 19 are embossed into a roughly box-shaped shape to form the lower housing. On the side of the second conductive plate 19, as described above, the area surrounded by the processing line 90 is punched out by a punch, thereby forming the corners of the embossed portion on the second sheet 32.

[0109] The battery cell 100 of the embodiment is formed by housing the battery module 1 including the stacked electrode assembly 10 and the resin sealant 40 between the upper and lower cases, and thermally welding the flange 21f of the upper case and the flange 22f of the lower case.

[0110] When the battery module 1 is housed in the upper and lower cases, the first conductive plate 18 of the upper case contacts the positive terminal electrode 16 and is electrically connected to the positive terminal electrode. Furthermore, the second conductive plate 19 of the lower case contacts the negative terminal electrode 17 and is electrically connected to the negative terminal electrode 17. This allows the first and second conductive plates 18 and 19 to function as terminals.

[0111] It should be noted that while the above description illustrates the case where the first and second laminated sheets are deep-drawn, this is not limiting. As long as they can accommodate the stacked electrode assembly 10, the first and / or second laminated sheets may remain in a sheet shape without embossing to form the receiving recesses 21c and 22c. Alternatively, a portion of the first and / or second laminated sheets may be bent along the outer shape of the storage module 1 housed therein.

[0112] As described above, in this embodiment, the plurality of first sheets 31 and the plurality of second sheets 32 cooperatively cover the peripheries of the first conductive plate 18 and the second conductive plate 19 while a portion of the first resin layer 321 overlaps a portion of the sealant resin layer 312 .

[0113] The sealant resin layer 312 is compatible with the first resin layer 321, and the sealant resin layer 311 and the first resin layer 321 are compatible and bonded to each other. This allows the sealant between the first laminate sheet portion 21 and the second laminate sheet portion 22 to be well maintained.

[0114] Furthermore, since the second sheet 32 ​​is provided with the second resin layer 322 having a higher strength than the sealant resin layers 311 and 312 , damage to the first laminated sheet portion 21 and the second laminated sheet portion 22 can be suppressed, thereby improving formability.

[0115] Furthermore, the first conductive plate 18 and the second conductive plate 19 are arranged so as to contact the terminal electrode of the stacked electrode body 10 and are electrically connected to the terminal electrode, thereby enabling current to be drawn in the stacking direction. The first conductive plate 18 and the second conductive plate 19 are formed from a member different from the stacked electrode body 10. Therefore, compared to a case where the first laminated sheet 21 and the second laminated sheet 22 are directly joined to the periphery of the stacked electrode body 10, if a poor joining occurs when joining the first laminated sheet 21 and the second laminated sheet 22 to the first conductive plate 18 and the second conductive plate 19, the stacked electrode body 10 does not need to be discarded.

[0116] Typically, at corners that are embossed (deep-drawn), the first and second laminated sheets 21 and 22 are stretched in various directions during the process, resulting in stress and potential damage. In this embodiment, for example, in the second sheet 32 ​​covering the multiple corners of the first and second conductive plates 18 and 19, the second metal layer 320 is thicker than the first metal layer 310 of the first sheet 31. Therefore, when the first and second laminated sheets 21 and 22 are embossed, damage to the first and second laminated sheets 21 and 22 (specifically, the second sheet 32) at the corners of the housing recesses 21c and 22c (embossed portions) can be further suppressed.

[0117] Note that, although the second metal layer 320 is thicker than the first metal layer 310 , the present invention is not limited thereto, and the second resin layer 322 may be thicker.

[0118] Furthermore, as described above, by arranging the first sheet 31 along the pair of first side portions 181 and the second sheet 32 ​​along the pair of second side portions 182, the peripheries of the first conductive plate 18 and the second conductive plate 19 can be efficiently surrounded by four sheets. Therefore, compared to a structure in which the center portion is cut out from a rectangular laminate sheet when forming the exterior body, loss of the laminate sheet is reduced.

[0119] (Implementation Method 2)

[0120] Figures 8 to 10 1 is a diagram showing a predetermined step in the process of manufacturing the first laminated sheet portion 21 of the second embodiment. Figures 8 to 10 , a stacked battery according to the second embodiment will be described.

[0121] When compared with the laminated battery 100 of the first embodiment, the laminated battery of the second embodiment has a different shape of the resin layer 50. The other structures are substantially the same.

[0122] Figure 8 This is a diagram showing a step of disposing a resin layer on the periphery of the first conductive plate in the process of manufacturing the first laminated sheet portion 21 according to the second embodiment.

[0123] like Figure 8 As shown, in the second embodiment, the resin layers 50A and 50B located on one and the other sides of the pair of second side portions 182 in the second direction have protruding pieces 55 at both ends in the first direction of the pair of first side portions 181. The protruding pieces 55 have outer end portions 55c on the outer sides in the first direction. The resin layers 50A and 50B located on one and the other sides in the second direction are arranged along the second side portions 182 so that the protruding pieces 55 protrude from the first conductive plate 18 to both outer sides in the first direction.

[0124] The resin layer 50 disposed at each side portion is disposed so that the outer edge portion 50c substantially coincides with each side portion. The outer edge portion 50c may be located outside the side portion.

[0125] Figure 9 This is a diagram showing a step of arranging the first sheet in the process of manufacturing the first laminated sheet unit 21 according to the second embodiment.

[0126] The first piece 31 is arranged along the first side 181 between the pair of second sides 182 on one side and the other side in the first direction. Specifically, the first piece 31A is arranged on one side in the first direction where the pair of first sides 181 face each other, and the first piece 31B is arranged on the other side in the first direction where the pair of first sides 181 face each other.

[0127] The first piece 31A and the first piece 31B are arranged along the first side 181 so as to span the protruding piece 55 located on one side in the second direction (the side where the resin layer 50A is located) and the protruding piece 55 located on the other side in the second direction (the side where the resin layer 50B is located).

[0128] The first piece 31A and the first piece 31B are arranged so that the outer end 31c is substantially aligned with the outer end 55c of the protruding piece 55. It should be noted that the position of the outer end 31c may be offset relative to the outer end 55c. The first piece 31A and the first piece 31B are arranged so that the inner end 31i is located on the resin layer 50. The inner edge 50i of the resin layer 50 is located closer to the center of the first conductive plate 18 than the inner end 31i. As described above, this ensures the insulation distance between the first conductive plate 18 and the first metal layer 310 of the first pieces 31A and 31B.

[0129] Figure 10 This is a diagram showing a step of arranging the second sheet in the process of manufacturing the first laminated sheet unit 21 according to the second embodiment.

[0130] The plurality of second sheets 32 are arranged so as to cover the periphery of the first conductive plate 18 in cooperation with the plurality of first sheets 31, with a portion of the first resin layer 321 overlapping the sealant resin layer 312. When viewed in the stacking direction, the second sheets 32 overlap the first sheets 31 at each corner of the first conductive plate 18.

[0131] The second sheet 32 ​​is arranged along the second side 182, covering the corners of the first conductive plate 18 on both sides in the first direction, on one side and the other side in the second direction. The second sheet 32A is arranged on one side in the second direction where the pair of second sides 182 face each other, and the second sheet 32B is arranged on the other side in the second direction. The second sheets 32A and 32B are arranged so that one end 32a substantially coincides with the outer end 55c of the protruding piece 55 on one side in the first direction (the side where the resin layer 50A is located), and the other end 32b substantially coincides with the outer end 55c of the protruding piece 55 on the other side in the first direction (the side where the resin layer 50B is located). Furthermore, the second sheet 32 ​​is arranged to overlap with the first sheet 31 in a manner substantially similar to that of the first embodiment.

[0132] The inner edge 50i of the resin layer 50 is located closer to the center of the first conductive plate 18 than the inner end 32i of the second sheet 32. This ensures an insulation distance between the first conductive plate 18 and the second metal layer 320 of the second sheet 32.

[0133] Figure 11 It is along Figure 10 A cross-sectional view along line XX is shown. Figure 11 The cross section of the portion where the first sheet 31 , the second sheet 32 ​​, and the resin layer 50 overlap on one side in the second direction is shown.

[0134] like Figure 11 As shown in the figure, by arranging the resin layer 50, the first sheet 31, and the second sheet 32 ​​as described above, when the resin layer 50, the first sheet 31, and the second sheet 32 ​​are thermally fused, at least the entire end surface of the first metal layer 310 in the second direction can be covered by the resin layer 50. Similarly, on the other side of the second direction, at least the entire end surface of the first metal layer 310 in the second direction can also be covered by the resin layer 50. In this way, the entire end surfaces of the first metal layer 310 in the second direction are covered by the resin layer 50.

[0135] Note that the first sheet 31 and the second sheet 32 ​​are also arranged on the second conductive plate 19 side in the same manner as on the first conductive plate 18 side.

[0136] In the second embodiment, the first laminated sheet consisting of the plurality of first sheets 31, the plurality of second sheets 32, and the first conductive plate 18 and the second laminated sheet consisting of the plurality of first sheets 31, the plurality of second sheets 32, and the second conductive plate 19 are also embossed. The stacked battery of the second embodiment is manufactured by housing the power storage module 1 in the embossed first and second laminated sheets.

[0137] Even with the above configuration, the laminated battery of Embodiment 2 can achieve substantially the same effects as the laminated battery 100 of Embodiment 1. Furthermore, both end faces of the first metal layer 310 on which the second sheet 32 ​​is stacked are covered with the resin layer 50, thereby suppressing undesirable short circuits caused through these end faces.

[0138] (Implementation Method 3)

[0139] Figure 12 and Figure 13 1 is a diagram showing a predetermined process in the process of manufacturing the first laminated sheet portion 21 of the third embodiment. Figure 12 and Figure 13 , a stacked battery according to a third embodiment will be described.

[0140] The laminated battery of the third embodiment differs from the laminated battery of the second embodiment in the shape of the first sheet 31 and the arrangement of the first sheet 31 and the second sheet 32. The other structures are substantially the same.

[0141] Figure 12 This is a diagram showing a step of arranging the first sheet in the process of manufacturing the first laminated sheet unit 21 according to the third embodiment.

[0142] The first piece 31 is arranged so as to protrude outward in the first direction from each of the multiple corners of the first conductive plate 18. Specifically, the first piece 31 is arranged on the protruding piece 55 so that the inner end 31i overlaps with the above-mentioned corner. The first piece 31 also has an inner end 31e and an outer end 31f in the second direction relative to the pair of second side portions 182. The inner end 31e is located closer to the center of the first conductive plate 18 than the outer end 31f. On one side of the above-mentioned first direction, a pair of first pieces 31A are arranged at intervals in the above-mentioned second direction. On the other side of the above-mentioned first direction, a pair of first pieces 31B are arranged at intervals in the above-mentioned second direction.

[0143] Figure 13 This is a diagram showing a step of arranging the second sheet in the process of manufacturing the first laminate sheet unit 21 according to the third embodiment.

[0144] The plurality of second sheets 32 are arranged so as to cover the periphery of the first conductive plate 18 in cooperation with the plurality of first sheets 31, with a portion of the first resin layer 321 overlapping the sealant resin layer 312. When viewed in the stacking direction, the second sheets 32 overlap the first sheets 31 at each corner of the first conductive plate 18.

[0145] The plurality of second sheets 32 include a pair of first side sheets 325A and 325B arranged along the pair of first sides 181 and a pair of second side sheets 326A and 326B arranged along the pair of second sides 182 .

[0146] The first side panel 325A is located on one side in the first direction of the pair of first sides 181. The first side panel 325B is located on the other side in the first direction. The first side panels 325A and 325B have end portions 325a on both sides in the second direction of the pair of second sides 182.

[0147] The second side piece 326A is positioned on one side in the second direction. The second side piece 326B is positioned on the other side in the second direction. The second side pieces 326A and 326B have end portions 326a on both sides in the first direction. Furthermore, the second side pieces 326A and 326B have inner end portions 326b located at the center of the first conductive plate 18.

[0148] The first side sheet 325A is arranged on the resin layer 50 so as to straddle the pair of first sheets 31A spaced apart in the second direction. The first side sheet 325A is arranged so that both ends 325a thereof cover the inner ends 31e of the pair of first sheets 31A.

[0149] The first side sheet 325B is arranged on the resin layer 50 so as to straddle the pair of first sheets 31B spaced apart in the second direction. The first side sheet 325B is arranged so that both ends 325a thereof cover the inner ends 31e of the pair of first sheets 31B.

[0150] The second side piece 326A is arranged on the resin layer 50 so as to straddle the pair of first pieces 31A and 31B spaced apart in the first direction. The second side piece 326A is arranged so that the inner end 326b covers the outer end 31f of each of the pair of first pieces 31A and 31B. The inner end 326b is opposed to the end 325a.

[0151] The second side piece 326B is arranged on the resin layer 50 so as to straddle the pair of first pieces 31A and 31B spaced apart in the first direction. The second side piece 326B is arranged so that the inner end 326b covers the outer end 31f of each of the pair of first pieces 31A and 31B. The inner end 326b is opposed to the end 325a.

[0152] By arranging the second sheet 32 ​​in this manner, even when the area of ​​the first sheet 31 is small, the second sheet 32 ​​can be stably arranged to overlap with the first sheet 31 .

[0153] The inner edge 50i of the resin layer 50 is located closer to the center of the first conductive plate 18 than the inner end 326b of the second sheet 32. This ensures an insulation distance between the first conductive plate 18 and the second metal layer 320 of the second sheet 32.

[0154] Note that the first sheet 31 and the second sheet 32 ​​are also arranged on the second conductive plate 19 side in the same manner as on the first conductive plate 18 side.

[0155] In the third embodiment, embossing is also performed on the first laminated sheet consisting of the plurality of first sheets 31, the plurality of second sheets 32, and the first conductive plate 18, and the second laminated sheet consisting of the plurality of first sheets 31, the plurality of second sheets 32, and the second conductive plate 19. The stacked battery of the third embodiment is manufactured by housing the power storage module 1 in the embossed first and second laminated sheets.

[0156] Even when configured as described above, the stacked battery of the third embodiment can achieve substantially the same effects as those of the stacked battery of the second embodiment.

[0157] (Implementation Method 4)

[0158] Figure 14 and Figure 15A diagram showing a predetermined step in the process of manufacturing the first laminated sheet portion 21 of the fourth embodiment. Figure 14 and Figure 15 , a stacked battery according to a fourth embodiment will be described.

[0159] When compared with the laminated battery 100 of the first embodiment, the laminated battery of the fourth embodiment has a shorter length of the first sheet 31 and a different shape of the second sheet 32 ​​.

[0160] Figure 14 This is a diagram showing a step of arranging the first sheet in the process of manufacturing the first laminated sheet unit 21 according to the fourth embodiment.

[0161] like Figure 14 As shown, the first piece 31 is arranged along the first side 181 between the pair of second sides 182 on one side and the other side in the first direction. The first piece 31A is arranged on one side in the first direction opposite the pair of first sides 181, and the first piece 31B is arranged on the other side in the first direction opposite the pair of first sides 181. The first pieces 31A and 31B are arranged so as not to reach the pair of second sides 182. That is, the length of the first pieces 31A and 31B in the second direction is shorter than that of the first side 181.

[0162] Figure 15 This is a diagram showing a step of arranging the second sheet in the process of manufacturing the first laminated sheet unit 21 according to the fourth embodiment.

[0163] The plurality of second sheets 32 are arranged so as to cover the periphery of the first conductive plate 18 in cooperation with the plurality of first sheets 31, with a portion of the first resin layer 321 overlapping the sealant resin layer 312. When viewed in the stacking direction, each corner of the first conductive plate 18 is covered only by the second sheets 32. The second sheets 32 overlap the first sheets 31 on the first side portion 181.

[0164] The second piece 32A is arranged on one side in the second direction where the pair of second side portions 182 face each other, and the second piece 32B is arranged on the other side in the second direction.

[0165] The second piece 32A has a base 327 extending along the second side 182 and protrusions 328 that protrude from both ends of the base 327 in the first direction toward the first pieces 31A and 31B. The protrusions 328 extend along the first side 181. The top 328a of the protrusions 328 covers one end 31a of the first pieces 31A and 31B.

[0166] The second piece 32B has a base 327 extending along the second side 182 and protrusions 328 that protrude from both ends of the base 327 in the first direction toward the first pieces 31A and 31B. The protrusions 328 extend along the first side 181. The top ends 328a of the protrusions 328 cover the other ends 31b of the first pieces 31A and 31B.

[0167] The inner edge portion 50i of the resin layer 50 is located closer to the center of the first conductive plate 18 than the inner end portion 31i of the first sheet 31 and the inner end portion 32i of the second sheet 32. This ensures an insulation distance between the first conductive plate 18 and the first metal layer 310 of the first sheet 31 and the second metal layer 320 of the second sheet 32.

[0168] Note that the first sheet 31 and the second sheet 32 ​​are also arranged on the second conductive plate 19 side in the same manner as on the first conductive plate 18 side.

[0169] In the fourth embodiment, embossing is also performed on the first laminated sheet consisting of the plurality of first sheets 31, the plurality of second sheets 32, and the first conductive plate 18, and the second laminated sheet consisting of the plurality of first sheets 31, the plurality of second sheets 32, and the second conductive plate 19. The stacked battery of the fourth embodiment is manufactured by housing the power storage module 1 in the embossed first and second laminated sheets.

[0170] Even with the above configuration, the laminated battery of Embodiment 4 can achieve substantially the same effects as the laminated battery 100 of Embodiment 1. Furthermore, by having the first sheet 31 and the second sheet 32 ​​have the above-described shapes, the seam between the first sheet 31 and the second sheet 32 ​​can be prevented from being located in a portion susceptible to wrinkling due to tension and stress during embossing. By positioning the seam away from the corners of the embossed portion, the loss of the laminated sheet due to punching can be minimized, reducing wrinkles during embossing.

[0171] (Implementation method 5)

[0172] Figure 16 This is a cross-sectional view of a stacked battery according to Embodiment 5. Figure 16 This is a cross-sectional view corresponding to the cross-sectional view along the III-III line. Figure 16 Next, a laminated battery 100D according to the fifth embodiment will be described.

[0173] like Figure 16 As shown, the laminated battery 100D of the fifth embodiment differs from the laminated battery 100 of the first embodiment in that it includes an outer resin layer 50D. The other structures are substantially the same.

[0174] The outer resin layer 50D covers the inner end portion 32i of the second sheet 32 ​​on the outer edge portion 18c of the first conductive plate 18 and the outer edge portion 19c of the second conductive plate 19. Specifically, the outer resin layer 50D is arranged on the resin layer 50 and the second sheet 32 ​​so as to cover the inner end portion 32i of the second sheet 32.

[0175] Although not shown here, on the first sheet 31 side, the outer resin layer 50D also covers the inner end portion 31i of the first sheet 31 on the outer edge portion 18c of the first conductive plate 18 and the outer edge portion 19c of the second conductive plate 19. Specifically, the outer resin layer 50D is arranged on the resin layer 50 and the first sheet 31 so as to cover the inner end portion 31i of the first sheet 31.

[0176] The outer resin layer 50D covers the first metal layer 310 and the second metal layer 320 exposed from the inner end portions 31 i and 32 i , thereby preventing the first conductive plate 18 and the second conductive plate 19 from short-circuiting with the first sheet 31 and the second sheet 32 ​​.

[0177] Figure 17 yes Figure 16 A cross-sectional view of the second sheet in the area surrounded by XVII shown. Figure 17 As shown, in the fifth embodiment, the outermost layer of the second resin layer 322 is formed of a resin material compatible with the outer resin layer 50D. Specifically, the outermost layer of the second resin layer 322 includes a polypropylene layer 36E, which is laminated on the nylon layer 35. The polypropylene layer 36E is compatible with the outer resin layer 50D disposed on the second resin layer 322. Therefore, by fusing the polypropylene layer 36E to the outer resin layer 50D, the sealing performance can be improved and the short circuit described above can be effectively suppressed.

[0178] The thickness of the polypropylene layer 36E may be greater than that of the nylon layer 35. For example, the thickness of the nylon layer 35 may be approximately 25 μm, and the thickness of the polypropylene layer 36E may be approximately 30 μm to 70 μm. In this case, the thickness of the polypropylene layer disposed on the outermost surface of the first resin layer 321 may be approximately 30 μm, and the thickness of the modified polypropylene disposed between the polypropylene layer and the second metal layer 320 may be approximately 30 μm. In other words, the thickness of each resin layer constituting the second resin layer 322 may be set to be less than half the thickness of the second metal layer 320.

[0179] Even with such a configuration, the stacked battery 100D according to the fifth embodiment can achieve the same effects as those of the stacked battery 100 according to the first embodiment.

[0180] (Implementation Method 6)

[0181] Figure 18This is a cross-sectional view of a stacked battery according to Embodiment 6. Figure 18 This is a cross-sectional view corresponding to the cross-sectional view along the III-III line. Figure 18 , a stacked battery 100E according to a seventh embodiment will be described.

[0182] like Figure 18 As shown, the stacked battery 100E according to the sixth embodiment differs from the stacked battery 100D according to the fifth embodiment in that the resin layer 50 is omitted.

[0183] In the sixth embodiment, by omitting the resin layer 50 , the second sheet 32 ​​is directly bonded to the outer edges of the first conductive plate 18 and the second conductive plate 19 . That is, the first resin layer 321 of the second sheet 32 ​​is directly bonded to the first conductive plate 18 and the second conductive plate 19 .

[0184] Although not shown here, on the first sheet 31 side, the first sheet 31 is also directly bonded to the outer edges of the first conductive plate 18 and the second conductive plate 19. In other words, the sealant resin layer 311 of the first sheet 31 is directly bonded to the first conductive plate 18 and the second conductive plate 19.

[0185] In this case, modified polypropylene (more specifically, acid-modified polypropylene), which has higher adhesion to metal than polypropylene, can be used as sealant resin layer 311 and first resin layer 321. Reducing the number of resin layers 50 reduces the number of components, improves productivity, and reduces manufacturing costs.

[0186] It should be noted that, in the above-described first to sixth embodiments, examples are provided in which a plurality of first sheets 31 and a plurality of second sheets cooperatively cover the periphery of the first conductive plate 18 and the periphery of the second conductive plate 19, but the present invention is not limited thereto. As long as the periphery of the first conductive plate 18 and the periphery of the second conductive plate 19 can be cooperatively covered, the number of first sheets 31 may be one or more, and the number of second sheets 32 may also be one or more. For example, a single first sheet 31 may cover a portion of the periphery of the first conductive plate 18 and a portion of the periphery of the second conductive plate 19, while a single second sheet 32 ​​may cover the rest of the periphery of the first conductive plate 18 and the rest of the periphery of the second conductive plate 19.

[0187] The embodiments disclosed herein are by way of illustration and not limitation in all respects. The scope of the present invention is indicated by the claims, and all modifications within the meaning and scope equivalent to the claims are intended to be encompassed.

[0188] Description of Reference Numerals

[0189] 1: Storage module, 10: Laminated electrode body, 11: Electrode plate, 12: Current collector, 12a: First surface, 12b: Second surface, 13: Positive electrode layer, 14: Negative electrode layer, 15: Separator, 16: Positive electrode end electrode, 17: Negative electrode end electrode, 18: First conductive plate, 18c: Outer edge, 19: Second conductive plate, 19c: Outer edge, 20: Outer body, 21: First laminated sheet, 21c, 22c: Receiver Concave portion, 21f: flange portion, 22: second laminated sheet portion, 22f: flange portion, 31, 31A, 31B: first sheet, 31a: one side end portion, 31b: the other side end portion, 31c: outer end portion, 31e: inner end portion, 31f: outer end portion, 31i: inner end portion, 32, 32A, 32B: second sheet, 32a: one side end portion, 32b: the other side end portion, 32c: outer end portion, 32i: Inner end, 33: Polypropylene layer, 34: Modified polypropylene layer, 35: Nylon layer, 36: Polyethylene terephthalate layer, 36E: Polypropylene layer, 40: Resin sealant, 50, 50A, 50B: Resin layer, 50c: Outer edge, 50D: Outer resin layer, 55: Protruding piece, 90: Processing line, 100: Laminated battery, 181: First side, 182: Second side, 310: First metal Layer, 311, 312: sealant resin layer, 320: second metal layer, 320a: first main surface, 320b: second main surface, 321: first resin layer, 322: second resin layer, 325A, 325B: first edge side piece, 325a, 326a: end, 326A, 326B: second edge side piece, 326b: inner end, 327: base, 328: protrusion, 328a: top.

Claims

1. A stacked battery, wherein: The stacked battery has: a stacked electrode body comprising a plurality of electrodes stacked in a stacking direction; as well as an outer body housing the stacked electrode body, The outer body comprises: a first conductive plate provided on one surface of the stacked electrode body in the stacking direction; a second conductive plate provided on the other surface of the stacked electrode body in the stacking direction; a first laminated sheet portion joined to a periphery of the first conductive plate; and The second laminated sheet is bonded to the periphery of the second conductive plate. The first laminated sheet portion and the second laminated sheet portion each include one or more first sheets and one or more second sheets. The one or more first sheets and the one or more second sheets cooperatively cover the periphery of the first conductive plate and the periphery of the second conductive plate in a state in which a portion of the second sheet overlaps a portion of the first sheet.

2. The stacked battery according to claim 1, wherein The first sheet includes a first metal layer and sealant resin layers provided on both surfaces of the first metal layer. The second sheet comprises: a second metal layer having a first main surface and a second main surface; and a first resin layer provided on one side of the first main surface. The first resin layer is compatible with the sealant resin layer. The one or more first sheets and the one or more second sheets cooperatively cover the periphery of the first conductive plate and the periphery of the second conductive plate in a state where a portion of the first resin layer overlaps a portion of the sealant resin layer. The sealant resin layer of the first sheet is compatible with the first resin layer of the second sheet.

3. The stacked battery according to claim 2, wherein: The side surfaces of the stacked electrode body are sealed by a sealing body, When viewed from the stacking direction, the first conductive plate and the second conductive plate each have a plurality of corners. At least one of the first laminated sheet portion and the second laminated sheet portion has an embossed portion for accommodating the laminated electrode body and the sealing body. The one or more second sheets are arranged so as to cover the plurality of corners. The second sheet has a second resin layer provided on the second main surface side. The second resin layer is a resin layer having a higher strength than the sealant resin layer or the first resin layer. The second sheet has corners of the embossed portion formed thereon.

4. The stacked battery according to claim 2, wherein A resin layer having compatibility with the sealant resin layer and the first resin layer is disposed between the one or more first sheets and the one or more second sheets and the periphery of the first conductive plate and the periphery of the second conductive plate. The one or more first sheets and the one or more second sheets have inner ends on the sides where the periphery of the first conductive plate and the periphery of the second conductive plate are located, respectively. When viewed in the stacking direction, the inner edge of the resin layer is located closer to the center of the stacked electrode body than the inner end.

5. The laminated battery according to any one of claims 1 to 4, wherein The stacked electrode body includes a positive terminal electrode located on one side of the stacking direction and a negative terminal electrode located on the other side of the stacking direction. The positive terminal electrode includes a current collector having a first surface on the one side in the stacking direction. The negative terminal electrode includes a current collector having a second surface on the other side in the stacking direction. The first conductive plate is electrically connected to the positive terminal electrode by being arranged in contact with the first surface. The second conductive plate is arranged in contact with the second surface to be electrically connected to the negative terminal electrode.

6. The stacked battery according to claim 5, wherein The first conductive plate and the second conductive plate each have a rectangular shape including a pair of first sides facing each other in a first direction and a pair of second sides facing each other in a second direction orthogonal to the first direction. In each of the first conductive plate and the second conductive plate, the first piece is disposed along the first side between the pair of second sides on one side and the other side in the first direction, In each of the first conductive plate and the second conductive plate, the second piece is arranged along the second side so as to cover corners of the first conductive plate and the second conductive plate located on both sides in the first direction, respectively, on one side and the other side in the second direction.

7. The stacked battery according to claim 6, wherein: The first sheet includes a first metal layer extending along the second direction, Both end surfaces of the first metal layer in the second direction are covered with the resin layer.

8. The stacked battery according to claim 5, wherein The first conductive plate and the second conductive plate each have a rectangular shape including a pair of first sides facing each other in a first direction and a pair of second sides facing each other in a second direction orthogonal to the first direction. In each of the first conductive plate and the second conductive plate, the first piece is arranged so as to protrude outward in the first direction from a plurality of corners. The second sheet includes a pair of first side sheets arranged along the pair of first sides and a pair of second side sheets arranged along the pair of second sides in each of the first conductive plate and the second conductive plate.

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