Battery

Abstract

To prevent occurrence of partial discharge between an electrode body and an outer packaging body.SOLUTION: An insulation sheet 50 includes a bottom surface part 500, a first lateral surface part 510, a second lateral surface part 511, a first left piece part 520, a second left piece part 521, a left bottom piece part 522, a first left connection part 523, and a second left connection part 524. On the insulation sheet 50, the first left piece part 520, the second left piece part 521, the left bottom piece part 522, the first left connection part 523, and the second left connection part 524 form a first communication path 530 which has a first opening end 531 at a position on the ends of the first left connection part 523 and the second left connection part 524 on an opening part 101 side of an outer packaging body 100, thereby bringing the inside of the insulation sheet 50 into communication with the outside thereof. The first communication path 530 is located on the shortest infiltration route for an electrolyte 80 which infiltrates from the outside of the insulation sheet 50 to an end part 20e of an electrode body 20 located on a bottom part 102 side of the outer packaging body 100 and closest to a ridge line part of one of a pair of second lateral walls 104a, 104b.SELECTED DRAWING: Figure 18

Description

Technical Field

[0001] The present technology relates to a battery.

Background Art

[0002] As a prior art document disclosing the configuration of an electricity storage device, there is JP 2019-29218 A (Patent Document 1). The electricity storage device described in Patent Document 1 includes an electrode assembly, an insulating holder, and an exterior case. The insulating holder accommodates the electrode assembly. The exterior case accommodates the electrode assembly together with the insulating holder and an electrolytic solution. The insulating holder is formed by folding an insulating sheet. The insulating sheet is composed of a plurality of sheet elements divided by a plurality of folds and a plurality of cuts.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When a short-circuit path to which a high voltage is applied is formed between the batteries located at both ends among a plurality of batteries connected in series due to water intrusion around the batteries or the like, a high voltage is applied between the electrode assembly and the exterior body inside the battery located in the short-circuit path, and through the gap between the electrode assembly and the exterior body formed by the cut of the insulating sheet, the insulation between the electrode assembly and the exterior body may be broken down, which may cause partial discharge.

[0005] The present technology has been made to solve the above problems, and an object thereof is to provide a battery capable of suppressing the occurrence of partial discharge between the electrode assembly and the exterior body.

Means for Solving the Problems

[0006] A battery based on this technology comprises an electrode body having a positive electrode plate and a negative electrode plate; a metal casing having an opening and housing the electrode body and electrolyte; a sealing plate that seals the opening; a positive electrode terminal electrically connected to the positive electrode plate and attached to the sealing plate; a negative electrode terminal electrically connected to the negative electrode plate and attached to the sealing plate; and a single insulating sheet disposed between the electrode body and the casing, wherein the casing has a bottom facing the opening, a pair of first side walls rising from the edge of the bottom and facing each other, and rising from the edge of the bottom and facing each other The insulating sheet has a bottom portion facing the bottom portion, a first side portion disposed between one of the pair of first side walls and the electrode body, a second side portion disposed between the other of the pair of first side walls and the electrode body, a first left side portion bent from one side end of the first side portion and disposed between one of the pair of second side walls and the electrode body, and a second side portion bent from one side end of the second side portion and between one of the pair of second side walls and the electrode body The first left side portion is positioned overlapping with at least a portion of the second left side portion, the second left side portion is positioned between one of the pair of second side walls and the electrode body, the second left side portion is provided continuously with each of the first left side portion and the second left side portion, and is bent at the boundary between each of the first left side portion and the second left side portion and sandwiched between the first left side portion and the second left side portion The electrode body includes a second left-side connecting portion which is bent at the boundary with each of the pieces and sandwiched between the second left-side piece and the left-side bottom piece, and the shortest path for the electrolyte to penetrate from the outside of the insulating sheet to the end of the electrode body that is closest to the bottom side of the outer casing and to the ridge of one of the pair of second side walls is a path that passes through the outer periphery of the first left-side connecting portion, the outer periphery of the left-side bottom piece, and the outer periphery of the second left-side connecting portion,The shortest distance between the portion on the shortest penetration path and the bottom portion is 5 mm or more, and the electrode body further comprises a tab portion provided on at least one of the positive electrode plate and the negative electrode plate, extending laterally, and a current collector connected to the tab portion, wherein the current collector includes a first region facing the second side wall, a third region located closer to the sealing plate than the first region and facing the second side wall, and a second region connecting the first region and the third region, and in the current collector and the second side wall facing each other, the shortest distance between the first region and the second side wall in a direction perpendicular to the second side wall is shorter than the shortest distance between the third region and the second side wall. [Effects of the Invention]

[0007] This technology makes it possible to suppress the occurrence of partial discharge between the electrode body and the outer casing. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view showing the configuration of a battery according to Embodiment 1 of this technology. [Figure 2] Figure 1 is a cross-sectional view of the battery as seen from the direction of the arrow along line II-II. [Figure 3] This is a perspective view showing the internal structure of a battery according to Embodiment 1 of this technology, excluding the outer casing and insulating sheet. [Figure 4] This is a front view showing the positive electrode raw plate before it is molded, which is included in the battery according to Embodiment 1 of this technology. [Figure 5] Figure 4 is a cross-sectional view of the positive electrode plate as seen from the direction of the VV arrow. [Figure 6] This is a front view showing the state after the positive electrode plate of the battery according to Embodiment 1 of this technology has been molded. [Figure 7] This is a front view showing the negative electrode raw plate before it is molded, which is included in the battery according to Embodiment 1 of this technology. [Figure 8] Figure 7 is a cross-sectional view of the negative electrode plate as seen from the direction of the arrow along line VIII-VIII. [Figure 9]This is a front view showing the state after the negative electrode plate included in the battery according to Embodiment 1 of the present technology is formed. [Figure 10] This is a perspective view showing the configurations of the electrode body and the current collector included in the battery according to Embodiment 1 of the present technology. [Figure 11] This is a cross-sectional view of the electrode body and the current collector in Fig. 10, viewed from the direction of the arrows along line XI-XI. [Figure 12] This is a cross-sectional view showing a state where the tab portion of the electrode body included in the battery according to Embodiment 1 of the present technology is bent. [Figure 13] This is an upper perspective view showing the configurations of part of the current collector and the sealing plate included in the battery according to Embodiment 1 of the present technology. [Figure 14] This is a lower perspective view showing the configurations of part of the current collector and the sealing plate included in the battery according to Embodiment 1 of the present technology. [Figure 15] This is an enlarged cross-sectional view showing part XV of the battery shown in Fig. 2. [Figure 16] This is an enlarged cross-sectional view showing part XVI of the battery shown in Fig. 2. [Figure 17] This is a perspective view showing the positional relationship between the battery case and the insulating sheet included in the battery according to Embodiment 1 of the present technology. [Figure 18] This is a perspective view showing the configuration of the battery excluding the outer exterior body included in the battery according to Embodiment 1 of the present technology. [Figure 19] This is an enlarged perspective view showing part XIX of the battery shown in Fig. 18. [Figure 20] This is a developed view showing the configuration of the insulating sheet included in the battery according to Embodiment 1 of the present technology. [Figure 21] This is a perspective view showing a state where the insulating sheet included in the battery according to Embodiment 1 of the present technology is bent. [Figure 22] This is a side view of the battery in Fig. 18, viewed from the direction of arrow XXII. [Figure 23] This is a cross-sectional view of the battery in Fig. 17, viewed from the direction of the arrows along line XXIII-XXIII. [Figure 24] This is a side view of the battery in Fig. 18, viewed from the direction of arrow XXIV. [Figure 25] This is a development view showing the configuration of an insulating sheet included in the battery according to Embodiment 2 of the present technology. [Figure 26] This is a side view showing the internal configuration of the battery according to Embodiment 2 of the present technology. [Mode for Carrying Out the Invention]

[0009] Hereinafter, embodiments of the present technology will be described. Note that the same reference numerals are assigned to the same or corresponding parts, and repeated descriptions thereof may be omitted in some cases.

[0010] In the embodiments described below, when references are made to numbers, amounts, and the like, the scope of the present technology is not necessarily limited to those numbers, amounts, and the like, unless otherwise specifically stated. Further, in the following embodiments, each constituent element is not necessarily essential to the present technology, unless otherwise specifically stated.

[0011] In the present specification, the descriptions of "comprise", "include" and "have" are open-ended. That is, when a certain configuration is included, other configurations other than the said configuration may or may not be included. In addition, the present technology is not necessarily limited to those that exhibit all of the operational effects referred to in the present embodiment.

[0012] In the present specification, "battery" is not limited to lithium-ion batteries, and may include other batteries such as nickel-metal hydride batteries. In the present specification, "electrode" may collectively refer to a positive electrode and a negative electrode. In addition, "electrode plate" may collectively refer to a positive electrode plate and a negative electrode plate.

[0013] In the present specification, "power storage cell" to "power storage module" are not limited to battery cells to battery modules, and may include capacitor cells to capacitor modules.

[0014] (Embodiment 1) Figure 1 is a perspective view showing the configuration of a battery according to Embodiment 1 of this technology. Figure 2 is a cross-sectional view of the battery in Figure 1, viewed from the direction of the arrow line II-II. Figure 3 is a perspective view showing the internal configuration of the battery according to Embodiment 1 of this technology, excluding the outer casing and insulating sheet.

[0015] As shown in Figures 1 to 3, the battery 1 comprises a battery case 10, an electrode body 20, a positive electrode current collector 30, a negative electrode current collector 40, an insulating sheet 50, a positive electrode external conductive member 60, and a negative electrode external conductive member 70. The battery case 10 includes an outer casing 100 and a sealing plate 110.

[0016] The outer casing 100 is a bottomed rectangular tube with an opening 101 into which the electrode body 20 can be inserted. The outer casing 100 houses the electrode body 20 and the electrolyte. The outer casing 100 is made of metal. Specifically, the outer casing 100 is made of aluminum, aluminum alloy, iron, or iron alloy.

[0017] The outer casing 100 has a bottom portion 102, a pair of first side walls 103a, 103b, and a pair of second side walls 104a, 104b.

[0018] The bottom 102 faces the opening 101. Each of the pair of first side walls 103a and 103b is erected from the edge of the bottom 102 and faces each other parallel to each other. Each of the pair of second side walls 104a and 104b is erected from the edge of the bottom 102 and faces each other parallel to each other. Each of the pair of second side walls 104a and 104b connects the first side walls 103a and 103b to each other. The area of ​​each of the pair of first side walls 103a and 103b is greater than the area of ​​each of the pair of second side walls 104a and 104b.

[0019] The sealing plate 110 seals the opening 101 of the outer casing 100. The sealing plate 110 is made of, for example, aluminum, aluminum alloy, iron, or iron alloy.

[0020] The sealing plate 110 is provided with an electrolyte injection hole 111. The electrolyte injection hole 111 is sealed by a sealing member 112. The sealing plate 110 is provided with a gas discharge valve 113 that ruptures when the pressure inside the battery case 10 exceeds a predetermined value, thereby releasing the gas inside the battery case 10 to the outside.

[0021] The electrode body 20 in this embodiment is a flat-shaped electrode body having a positive electrode plate and a negative electrode plate, which will be described later. Specifically, the electrode body 20 is a wound-type electrode body in which a strip-shaped positive electrode plate and a strip-shaped negative electrode plate are wound together via a strip-shaped separator (not shown).

[0022] As shown in Figures 2 and 3, the battery case 10 houses the electrode bodies 20. Specifically, multiple wound electrode bodies are housed together with an electrolyte (not shown) inside an insulating sheet 50 placed within the outer casing 100 of the battery case 10. In this embodiment, the battery case 10 houses three wound electrode bodies. The electrode bodies 20 are housed within the outer casing 100 with their winding axes oriented parallel to the bottom portion 102. The number of electrode bodies 20 arranged within the outer casing 100 is not limited to three. Furthermore, the electrode bodies 20 are not limited to wound electrode bodies, but may be laminated electrode bodies in which multiple positive electrode plates and multiple negative electrode plates are alternately stacked.

[0023] The electrode body 20 has tab portions 21 provided on at least one of the positive electrode plate and the negative electrode plate, extending laterally from the electrode body 20. In the electrode body 20 in this embodiment, a group of positive electrode tabs 210, including a plurality of positive electrode tabs, is provided as one tab portion 21 at one end of the electrode body 20 in the direction in which the winding axis extends. A group of negative electrode tabs 260, including a plurality of negative electrode tabs, is provided as the other tab portion 21 at the other end of the electrode body 20 in the direction in which the winding axis extends.

[0024] It is preferable that the electrode body 20 is placed inside the outer casing 100 with an insulating sheet 50 in between, such that one second side wall 104a faces the positive electrode tab group 210, and the other second side wall 104b faces the negative electrode tab group 260.

[0025] As shown in Figures 1 to 3, a positive electrode terminal 230 and a negative electrode terminal 280 are attached to the sealing plate 110. Specifically, as shown in Figures 2 and 3, the positive electrode terminal 230 is electrically connected to the group of positive electrode tabs 210 in each of the multiple electrode bodies 20 via the positive electrode current collector 30. A positive electrode external conductive member 60 is connected to the positive electrode terminal 230. Note that the battery 1 does not necessarily need to include the positive electrode external conductive member 60.

[0026] The positive electrode terminal 230 and the positive electrode external conductive member 60 are preferably made of metal, and more preferably of aluminum or an aluminum alloy.

[0027] The negative electrode terminal 280 is electrically connected to the group of negative electrode tabs 260 in each of the multiple electrode bodies 20 via the negative electrode current collector 40. The negative electrode terminal 280 is connected to the negative electrode external conductive member 70. Note that the battery 1 does not necessarily need to include the negative electrode external conductive member 70.

[0028] The negative electrode terminal 280 is preferably made of metal, and more preferably of copper or a copper alloy. The negative electrode external conductive member 70 is preferably made of metal, and more preferably of aluminum or an aluminum alloy. The negative electrode terminal 280 may have a region connected to the negative electrode current collector 40 made of copper or a copper alloy, and a region protruding outward from the sealing plate 110 made of aluminum or an aluminum alloy.

[0029] The positive electrode current collector 30 has a plate-like shape. The positive electrode current collector 30 is connected to one of the tab portions 21. In this embodiment, the positive electrode current collector 30 is connected to the positive electrode tab group 210. The positive electrode current collector 30 is preferably made of metal, and more preferably of aluminum or an aluminum alloy.

[0030] In this embodiment, the positive electrode current collector 30 includes a first positive electrode current collector 300 as an extended current collector and a second positive electrode current collector 310 as a current collector.

[0031] The first positive electrode current collector 300 is connected to the positive electrode terminal 230 between the electrode body 20 and the sealing plate 110. The first positive electrode current collector 300 is connected to the second positive electrode current collector 310 at the end opposite to the side to which the positive electrode terminal 230 is connected. The second positive electrode current collector 310 is connected to the positive electrode tab group 210 at the end opposite to the side to which it is connected to the first positive electrode current collector 300. The positive electrode current collector 30 may be composed of a single component.

[0032] The negative electrode current collector 40 has a plate-like shape. The negative electrode current collector 40 is connected to the other tab portion 21. In this embodiment, the negative electrode current collector 40 is connected to the negative electrode tab group 260. The negative electrode current collector 40 is preferably made of metal, and more preferably of copper or a copper alloy.

[0033] In this embodiment, the negative electrode current collector 40 includes a first negative electrode current collector 400 as an extension current collector and a second negative electrode current collector 410 as a current collector. The first negative electrode current collector 400 is connected to the negative electrode terminal 280 between the electrode body 20 and the sealing plate 110. The first negative electrode current collector 400 is connected to the second negative electrode current collector 410 at the end opposite to the side to which the negative electrode terminal 280 is connected. The second negative electrode current collector 410 is connected to the negative electrode tab group 260 on the side opposite to the side to which it is connected to the first negative electrode current collector 400. The negative electrode current collector 40 may be composed of a single component.

[0034] As shown in Figure 2, a single insulating sheet 50 is placed between the electrode body 20 and the outer casing 100. The insulating sheet 50 is preferably made of resin. The material of the insulating sheet 50 is preferably, for example, polypropylene (PP), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyimide (PI), or polyolefin (PO). In particular, PP is preferred as the material of the insulating sheet 50.

[0035] The melting point of the insulating sheet 50 is preferably 100°C to 400°C, more preferably 120°C to 300°C, and particularly preferably 150°C to 170°C.

[0036] The thickness of the insulating sheet 50 is preferably 0.05 mm or more and 1 mm or less, more preferably 0.08 mm or more and 0.5 mm or less, and particularly preferably 0.1 mm or more and 0.2 mm or less.

[0037] The following describes the details of each component of battery 1 and the manufacturing method of battery 1. First, the positive electrode plate will be described.

[0038] Figure 4 is a front view showing the positive electrode base plate of the battery according to Embodiment 1 of this technology before it is formed. Figure 5 is a cross-sectional view of the positive electrode base plate of Figure 4 as seen from the direction of the VV arrow. Figure 6 is a front view showing the state after the positive electrode plate of the battery according to Embodiment 1 of this technology has been formed.

[0039] The positive electrode plate is manufactured by processing a positive electrode base plate 200S. As shown in Figures 4 and 5, the positive electrode base plate 200S includes a positive electrode core 201, a positive electrode active material layer 202, and a positive electrode protective layer 203. The positive electrode core 201 is aluminum foil or aluminum alloy foil.

[0040] A positive electrode active material layer 202 is formed on the positive electrode core 201, except for one end on both sides. The positive electrode active material layer 202 is formed on the positive electrode core 201 by applying a positive electrode active material slurry using a die coater.

[0041] The positive electrode active material layer slurry is prepared by kneading lithium nickel cobalt manganese composite oxide as the positive electrode active material, polyvinylidene fluoride (PVdF) as a binder, carbon material as a conductive material, and N-methyl-2-pyrrolidone (NMP) as a dispersion medium, such that the mass ratio of lithium nickel cobalt manganese composite oxide:PVdF:carbon material is 97.5:1:1.5.

[0042] The positive electrode protective layer 203 is formed on one end of the positive electrode active material layer 202 in the width direction, while in contact with the positive electrode core 201. The positive electrode protective layer 203 is formed on the positive electrode core 201 by applying a positive electrode protective layer slurry with a die coater.

[0043] The positive electrode protective layer slurry is prepared by kneading alumina powder, carbon material as a conductive material, PVdF as a binder, and NMP as a dispersion medium in a mass ratio of alumina powder:carbon material:PVdF of 83:3:14.

[0044] The positive electrode core 201, coated with the positive electrode active material layer slurry and the positive electrode protective layer slurry, is dried to remove NMP contained in the positive electrode active material layer slurry and the positive electrode protective layer slurry. This forms the positive electrode active material layer 202 and the positive electrode protective layer 203. Furthermore, the positive electrode active material layer 202 is compressed to form a positive electrode base plate 200S containing the positive electrode core 201, the positive electrode active material layer 202, and the positive electrode protective layer 203. The positive electrode base plate 200S is cut into a predetermined shape to form a positive electrode plate. The positive electrode base plate 200S can be cut by laser processing using energy beam irradiation, mold processing, or cutter processing.

[0045] As shown in Figure 6, a plurality of positive electrode tabs 220, each consisting of a positive electrode core 201, are provided at one end in the width direction of the positive electrode plate 200 formed from the positive electrode base plate 200S. Considering the state in which the plurality of positive electrode tabs 220 are stacked and connected to the positive electrode current collector 30 as a group of positive electrode tabs 210, the length or width in the protruding direction of each of the plurality of positive electrode tabs 220 is appropriately adjusted depending on the position in which each of the plurality of positive electrode tabs 220 is formed.

[0046] A positive electrode protective layer 203 is provided at the base of each of the multiple positive electrode tabs 220. However, the positive electrode tab group 210 does not necessarily need to have a positive electrode protective layer 203.

[0047] Next, the negative electrode plate will be described. Figure 7 is a front view showing the negative electrode raw material before it is molded for the battery according to Embodiment 1 of this technology. Figure 8 is a cross-sectional view of the negative electrode raw material in Figure 7, viewed from the direction of the line VIII-VIII arrow. Figure 9 is a front view showing the negative electrode plate of the battery according to Embodiment 1 of this technology after it has been molded.

[0048] The negative electrode plate is manufactured by processing the negative electrode base plate 250S. As shown in Figures 7 and 8, the negative electrode base plate 250S includes a negative electrode core 251 and a negative electrode active material layer 252. The negative electrode core 251 is copper foil or copper alloy foil.

[0049] The negative electrode core body 251 has a negative electrode active material layer 252 formed on all sides except for one end. The negative electrode active material layer 252 is formed by applying a negative electrode active material slurry using a die coater.

[0050] The negative electrode active material layer slurry is prepared by kneading graphite as the negative electrode active material, styrene-butadiene rubber (SBR) and carboxymethylcellulose (CMC) as binders, and water as a dispersion medium, so that the mass ratio of graphite:SBR:CMC is 98:1:1.

[0051] The negative electrode core 251, to which the negative electrode active material layer slurry has been applied, is dried to remove water contained in the negative electrode active material layer slurry. This forms the negative electrode active material layer 252. Furthermore, the negative electrode active material layer 252 is compressed to form a negative electrode base plate 250S containing the negative electrode core 251 and the negative electrode active material layer 252. The negative electrode base plate 250S is cut into a predetermined shape to form a negative electrode plate 250. The negative electrode base plate 250S can be cut by laser processing using energy beam irradiation, mold processing, or cutter processing.

[0052] As shown in Figure 9, a plurality of negative electrode tabs 270, each made of a negative electrode core 251, are provided at one end in the width direction of the negative electrode plate 250 formed from the negative electrode base plate 250S. Considering the state in which the plurality of negative electrode tabs 270 are stacked and connected to the negative electrode current collector 40 as a group of negative electrode tabs 260, the length or width in the protruding direction of each of the plurality of negative electrode tabs 270 is appropriately adjusted depending on the position in which each of the plurality of negative electrode tabs 270 is formed.

[0053] Next, the electrode body 20, the positive electrode current collector 30, and the negative electrode current collector 40 will be described. Figure 10 is a perspective view showing the configuration of the electrode body and current collector of the battery according to Embodiment 1 of this technology. In Figure 10, the tab portion 21 is shown in its state before it is bent.

[0054] As shown in Figure 10, the strip-shaped positive electrode plate 200 and the strip-shaped negative electrode plate 250, which were prepared by the method described above, are wound around a strip-shaped separator (not shown) to produce a flattened electrode body 20. The separator is preferably made of a polyolefin substrate with a heat-resistant layer on its surface. This heat-resistant layer contains ceramic particles and a binder. As ceramic particles, for example, aluminum oxide, boehmite, aluminum hydroxide, or titania can be used.

[0055] A group of positive electrode tabs 210, including a plurality of positive electrode tabs 220 provided on the positive electrode plate 200, is arranged at one end of the electrode body 20 on the side in the direction in which the winding axis of the electrode body 20 extends.

[0056] The thickness of the positive electrode tab 220 is preferably 5 μm or more and 30 μm or less, and more preferably 8 μm or more and 20 μm or less. The number of stacked positive electrode tabs 220 in the positive electrode tab group 210 is preferably 10 or more, more preferably 20 or more, and particularly preferably 30 or more.

[0057] At the other end of the electrode body 20 on the side in the direction in which the winding axis of the electrode body 20 extends, a group of negative electrode tabs 260, including a plurality of negative electrode tabs 270 provided on the negative electrode plate 250, is arranged. Thus, the tab portion 21 is composed of at least one of the positive electrode tab group 210 and the negative electrode tab group 260. In this embodiment, the tab portion 21 is composed of the positive electrode tab group 210 and the negative electrode tab group 260.

[0058] The thickness of the negative electrode tab 270 is preferably 5 μm or more and 30 μm or less, more preferably 8 μm or more and 20 μm or less. The number of stacked negative electrode tabs 270 in the negative electrode tab group 260 is preferably 10 or more, more preferably 20 or more, and particularly preferably 30 or more.

[0059] The second positive electrode current collector 310 has a first region 311, a second region 312, and a third region 313. As shown in Figure 2, the first region 311 faces one of the second side walls 104a. A tab portion 21 is connected to the first region 311.

[0060] As shown in Figures 2 and 10, the second region 312 is located on the sealing plate 110 side of the first region 311. The second region 312 is inclined with respect to both the first region 311 and the third region 313.

[0061] The third region 313 is located on the sealing plate 110 side of the second region 312 and faces one of the second side walls 104a. The third region 313 is connected to the first positive electrode current collector 300.

[0062] As shown in Figure 2, the first region 311 and the third region 313 are arranged such that their planar portions are substantially perpendicular to the winding axis of the electrode body 20. In the opposing second positive electrode current collector 310 and one of the second side walls 104a, the shortest distance between the first region 311 and one of the second side walls 104a in a direction perpendicular to one of the second side walls 104a is shorter than the shortest distance between the third region 313 and one of the second side walls 104a.

[0063] As shown in Figure 10, a recess 314 is provided in the third region 313. The portion with the recess 314 is thinner than its surroundings. A through hole 315 is provided in the recess 314. The third region 313 is joined to the first positive electrode current collector 300 at the recess 314. A fuse hole 316 can be provided in the second positive electrode current collector 310.

[0064] The second negative electrode current collector 410, like the second positive electrode current collector 310, has a first region 411, a second region 412, and a third region 413. The third region 413 is provided with a recess 414 and a through hole 415. The third region 413 is joined to the first negative electrode current collector 400 at the recess 414.

[0065] Next, the connection between the current collector and the tab portion 21 will be described. Figure 11 is a cross-sectional view of the electrode body and current collector in Figure 10, viewed from the direction of the XI-XI arrow. Figure 12 is a cross-sectional view showing the state in which the tab portion of the electrode body of the battery according to Embodiment 1 of this technology is bent.

[0066] As shown in Figure 11, the tip 221 of the positive electrode tab group 210, which includes multiple positive electrode tabs 220, is positioned adjacent to the first region 311 of the second positive electrode current collector 310, and the first region 311 and the positive electrode tab group 210 are joined together. This joining forms a tab joint 320. As a method for joining the first region 311 and the positive electrode tab group 210, ultrasonic welding, resistance welding, or laser welding can be used.

[0067] As shown in Figure 12, the group of positive electrode tabs 210 on which the tab joint 320 is formed is curved by bending. The bent tip portion 221 of the tab portion 21 faces at least one of the pair of second side walls 104a and 104b. In this embodiment, the tip portion 221 faces one of the second side walls 104a. In this way, the second positive electrode current collector 310 faces the side surface of the battery case 10 due to the bending of the group of positive electrode tabs 210. The tab joint 320 may be joined to the surface in the first region 311 opposite to the electrode body 20.

[0068] The negative electrode tab group 260, like the positive electrode tab group 210, is positioned adjacent to the first region 411 of the second negative electrode current collector 410, and the negative electrode tab group 260 is joined to the first region 411. This joining forms a tab joint. The negative electrode tab group 260, with the tab joint formed, is curved by bending. The bent tip of the tab portion 21 faces at least one of the pair of second side walls 104a and 104b. In this embodiment, the tip faces the other second side wall 104b. In this way, the second negative electrode current collector 410 faces the other second side wall 104b because the negative electrode tab group 260 is bent.

[0069] In the first region 311 of the second positive electrode current collector 310, it is preferable that the tab joint portion 320 is positioned closer to the base of the positive electrode tab group 210. With this configuration, when the positive electrode tab group 210 is bent, a stable curved shape can be formed near the base of the positive electrode tab group 210. In the first region 411 of the second negative electrode current collector 410, the position where the negative electrode tab group 260 is joined is the same as in the case of the second positive electrode current collector 310.

[0070] As shown in Figure 2, it is preferable that the bottom 102 side end of the outer casing 100 of the second positive electrode current collector 310 is located closer to the bottom 102 than the bottom 102 side end of the outer casing 100 of the positive electrode tab group 210. With this configuration, the positive electrode tab group 210 can be bent stably during the bending process. The lower end of the second negative electrode current collector 410 is the same as that of the second positive electrode current collector 310.

[0071] Next, the sealing plate 110 will be described. Figure 13 is an upper perspective view showing the configuration of a part of the current collector and the sealing plate of the battery according to Embodiment 1 of this technology. Figure 14 is a lower perspective view showing the configuration of a part of the current collector and the sealing plate of the battery according to Embodiment 1 of this technology. Figure 15 is an enlarged cross-sectional view showing part XV of the battery shown in Figure 2. Figure 16 is an enlarged cross-sectional view showing part XVI of the battery shown in Figure 2. In Figure 13, the sealing plate 110 is shown from the outside of the battery 1, and in Figure 14, the sealing plate 110 is shown from the inside of the battery 1.

[0072] As shown in Figures 13 and 15, the sealing plate 110 has a positive terminal mounting hole 114 near one end and a negative terminal mounting hole 115 near the other end.

[0073] As shown in Figures 13 to 15, in the sealing plate 110, the first external insulating member 231 is arranged around the positive terminal mounting hole 114 on the side opposite to the electrode body 20, and the internal insulating member 240 and the first positive current collector 300 are arranged around the positive terminal mounting hole 114 on the side facing the electrode body 20.

[0074] The positive terminal 230 is inserted from the outside of the battery 1 into the through hole 232h of the second external insulating member 232, the positive terminal mounting hole 114 of the sealing plate 110, the through hole 240h of the internal insulating member 240, and the through hole 301h of the first positive current collector 300. The positive terminal 230 is crimped onto the first positive current collector 300, forming a crimped portion 230A. Alternatively, the crimped portion 230A of the positive terminal 230 may be welded to the first positive current collector 300 after crimping.

[0075] As shown in Figures 13, 14, and 16, in the sealing plate 110, the first external insulating member 281 is arranged on the side of the negative electrode terminal mounting hole 115 opposite to the electrode body 20, and the internal insulating member 290 and the first negative electrode current collector 400 are arranged on the side of the negative electrode terminal mounting hole 115 that is on the electrode body 20 side.

[0076] The negative electrode terminal 280 is inserted from the outside of the battery 1 into the through hole 282h of the second external insulating member 282, the negative electrode terminal mounting hole 115 of the sealing plate 110, the through hole 290h of the internal insulating member 290, and the through hole 401h of the first negative electrode current collector 400. The negative electrode terminal 280 is crimped onto the first negative electrode current collector 400, forming a crimped portion 280A. Alternatively, the crimped portion 280A of the negative electrode terminal 280 may be welded to the first negative electrode current collector 400 after crimping.

[0077] The timing of connecting the positive electrode external conductive member 60 to the positive electrode terminal 230, or the negative electrode external conductive member 70 to the negative electrode terminal 280, is not particularly limited. This connection may occur after the positive electrode terminal 230 and the negative electrode terminal 280 have been fixed to the sealing plate 110, or after the electrolyte injection hole 111 of the sealing plate 110 connected to the outer casing 100 has been sealed.

[0078] As shown in Figures 13 to 15, the first positive electrode current collector 300, which is an extended current collector, has an L-shape in cross-section. The first positive electrode current collector 300 has a base portion 301 and a current collector connection portion 302. The base portion 301 is positioned between the electrode body 20 and the sealing plate 110, along the sealing plate 110 via an internal insulating member 240.

[0079] The current collector connection portion 302 is bent from the end of the base portion 301 and extends toward the bottom portion 102. The current collector connection portion 302 is connected to the third region 313 of the second positive electrode current collector 310. The current collector connection portion 302 is positioned between one second side wall 104a of the outer casing 100 and the electrode body 20.

[0080] As shown in Figures 13, 14, and 16, the first negative electrode current collector 400, which is an extended current collector, has an L-shape in cross-section. The first negative electrode current collector 400 has a base portion 401 and a current collector connection portion 402. The base portion 401 is positioned between the electrode body 20 and the sealing plate 110, along the sealing plate 110 via an internal insulating member 290.

[0081] The current collector connector 402 is bent from the end of the base 401 and extends toward the bottom 102. The current collector connector 402 is connected to the third region 413 of the second negative electrode current collector 410. The current collector connector 402 is positioned between the other second side wall 104b of the outer casing 100 and the electrode body 20.

[0082] Next, the connection between the first and second current collectors will be explained. As shown in Figure 3, three electrode bodies 20, each fitted with a second positive electrode current collector 310 and a second negative electrode current collector 410, are arranged side by side. In this case, the positive electrode tab groups 210 and negative electrode tab groups 260 of each of the three electrode bodies 20 are positioned on the same side.

[0083] With each of the positive electrode tab groups 210 of the three electrode bodies 20 curved, the second positive electrode current collector 310 attached to the three electrode bodies 20 is joined to the current collector connection portion 302 of the first positive electrode current collector 300 fixed to the sealing plate 110. As a result, the joint between the current collector connection portion 302 and the third region 313 is formed within the recess 314.

[0084] With each of the negative electrode tab groups 260 of the three electrode bodies 20 curved, the second negative electrode current collector 410 attached to the three electrode bodies 20 is joined to the current collector connection portion 402 of the first negative electrode current collector 400 fixed to the sealing plate 110. As a result, the joint between the current collector connection portion 402 and the third region 413 is formed within the recess 414.

[0085] As a method for connecting the first positive electrode current collector 300 and the second positive electrode current collector 310, or the first negative electrode current collector 400 and the second negative electrode current collector 410, ultrasonic welding, resistance welding, or laser welding using high-energy rays can be used. Laser welding is particularly preferred.

[0086] Next, the insertion of the electrode body 20 into the outer casing 100 will be described. As shown in Figure 2, the electrode body 20 is placed inside an insulating sheet 50 that is shaped like a bag or box. The electrode body 20 covered with the insulating sheet 50 is then inserted into the outer casing 100. As a result, multiple wound electrode bodies are housed inside the battery case 10. Next, the sealing plate 110 is joined to the opening 101 of the outer casing 100 by laser welding or the like.

[0087] Subsequently, a non-aqueous electrolyte is injected through the electrolyte injection hole 111 provided in the sealing plate 110, and the electrolyte injection hole 111 is sealed with the sealing member 112. This completes the battery 1. The positive electrode plate 200, negative electrode plate 250, separator, electrolyte, and materials constituting each mechanical component used in the battery 1 according to this embodiment can be those of known origin.

[0088] The structure of the insulating sheet 50 in Embodiment 1 of this technology will be described in detail below.

[0089] Figure 17 is a perspective view showing the positional relationship between the battery case and the insulating sheet of the battery according to Embodiment 1 of this technology. Figure 18 is a perspective view showing the configuration of the battery according to Embodiment 1 of this technology, excluding the outer casing.

[0090] As shown in Figures 17 and 18, the insulating sheet 50 includes a bottom portion 500, a first side portion 510, a second side portion 511, a first left side portion 520, a second left side portion 521, a left bottom portion 522, a first left connection portion 523, and a second left connection portion 524.

[0091] The bottom portion 500 is positioned between the electrode body 20 and the bottom portion 102 of the outer casing 100. The bottom portion 500 faces the bottom portion 102.

[0092] The first side portion 510 is positioned between one of the pair of first side walls 103a, 103b and the electrode body 20. In this embodiment, the first side portion 510 is positioned between one of the first side walls 103a and the electrode body 20.

[0093] The second side portion 511 is positioned between the other of the pair of first side walls 103a, 103b and the electrode body 20. In this embodiment, the second side portion 511 is positioned between the other first side wall 103b and the electrode body 20.

[0094] The first left-side portion 520 is bent from one lateral end of the first side portion 510. In this embodiment, the first left-side portion 520 is bent from the lateral end of the first side portion 510 on the positive electrode side of the battery 1.

[0095] The first left-side portion 520 is positioned between one of the pair of second side walls 104a, 104b and the electrode body 20. In this embodiment, the first left-side portion 520 is positioned between one of the second side walls 104a and the electrode body 20.

[0096] The second left-side portion 521 is bent from one lateral end of the second side portion 511. In this embodiment, the second left-side portion 521 is bent from the lateral end of the second side portion 511 on the positive electrode side of the battery 1.

[0097] The second left portion 521 is positioned between one of the pair of second side walls 104a, 104b and the electrode body 20, overlapping with at least a portion of the first left portion 520. In this embodiment, the second left portion 521 is positioned between one of the second side walls 104a and the electrode body 20.

[0098] The left bottom piece 522 rises from one of the lateral ends of the bottom surface 500. In this embodiment, the left bottom piece 522 rises from the lateral end of the bottom surface 500 on the positive electrode side of the battery 1.

[0099] The left bottom portion 522 is located outside the first left portion 520 and the second left portion 521, which overlap each other, between one of the pair of second side walls 104a and 104b and the electrode body 20. In this embodiment, the left bottom portion 522 is located between one of the second side walls 104a and the electrode body 20, on the side of one of the second side walls 104a, and is located on the side of the first left portion 520 and the second left portion 521 toward one of the second side walls 104a.

[0100] The first left-side connecting portion 523 is provided continuously with each of the first left-side piece 520 and the left-side bottom piece 522. The first left-side connecting portion 523 is bent at the boundary with each of the first left-side piece 520 and the left-side bottom piece 522 and is sandwiched between the first left-side piece 520 and the left-side bottom piece 522.

[0101] The second left-side connecting portion 524 is provided continuously with each of the second left-side piece 521 and the left-side bottom piece 522. The second left-side connecting portion 524 is bent at the boundary with each of the second left-side piece 521 and the left-side bottom piece 522 and is sandwiched between the second left-side piece 521 and the left-side bottom piece 522.

[0102] Figure 19 is a magnified perspective view of section XIX of the battery shown in Figure 18.

[0103] As shown in Figure 19, the insulating sheet 50 has a first communication passage 530 that connects the inside and outside of the insulating sheet 50. The first communication passage 530 is composed of a first left side portion 520, a second left side portion 521, a left bottom portion 522, a first left connection portion 523, and a second left connection portion 524. The first communication passage 530 is a gap formed when each of the first left side portion 520, the second left side portion 521, the left bottom portion 522, the first left connection portion 523, and the second left connection portion 524 is bent and adjacent to each other, allowing the electrolyte to flow between the inside and outside of the insulating sheet 50 through the first communication passage 530.

[0104] The first connecting passage 530 has a first open end 531. The first open end 531 is located at the end of the exterior body 100 of the first left-side connecting portion 523 and the second left-side connecting portion 524 on the opening 101 side. In this embodiment, the first open end 531 is located at the end of the exterior body 100 of the left-side bottom piece portion 522, the first left-side connecting portion 523, and the second left-side connecting portion 524 on the opening 101 side.

[0105] Figure 20 is an exploded view showing the configuration of the insulating sheet provided in the battery according to Embodiment 1 of this technology.

[0106] As shown in Figures 18 and 20, a single insulating sheet 50 is folded to form a bottomed cylindrical shape. As shown in Figure 20, the bottom portion 500 has a rectangular shape with a pair of long sides and a pair of short sides perpendicular to the pair of long sides.

[0107] The first side portion 510 is connected to one of the pair of long sides of the bottom portion 500. Specifically, the first side portion 510 and the bottom portion 500 are continuously connected along the entire length of one of the pair of long sides of the bottom portion 500.

[0108] The second side portion 511 is connected to the other of the pair of long sides of the bottom portion 500. Specifically, the second side portion 511 and the bottom portion 500 are continuously connected along the entire length of the other of the pair of long sides of the bottom portion 500.

[0109] The bottom surface 500 and the left bottom piece 522 are continuously connected along the entire length of one of the pair of short sides of the bottom surface 500.

[0110] In this embodiment, the first side portion 510 and the first left side portion 520 are continuously connected along the entire length of the area facing the electrode body 20 at the boundary between the first side portion 510 and the first left side portion 520. However, there may be a discontinuity between the first side portion 510 and the first left side portion 520 at the upper end portion that does not face the electrode body 20, where a notch or through hole is formed.

[0111] In this embodiment, the second side portion 511 and the second left side portion 521 are continuously connected along the entire length of the area facing the electrode body 20 at the boundary between the second side portion 511 and the second left side portion 521. However, there may be a discontinuous area between the second side portion 511 and the second left side portion 521 at the upper end portion that does not face the electrode body 20, where a notch or through hole is formed.

[0112] The insulating sheet 50 has a first fold line 551, a second fold line 552, a third fold line 553, a fourth fold line 554, a fifth fold line 555, a sixth fold line 556, a seventh fold line 557, an eighth fold line 558, and a ninth fold line 559 formed on it.

[0113] The first fold line 551 is formed at the boundary between the bottom portion 500 and the first side portion 510. The second fold line 552 is formed at the boundary between the bottom portion 500 and the second side portion 511. The third fold line 553 is formed at the boundary between the first side portion 510 and the first left side portion 520. The fourth fold line 554 is formed at the boundary between one of the pair of short sides of the bottom portion 500 and the left bottom portion 522. The fifth fold line 555 is formed at the boundary between the second side portion 511 and the second left side portion 521. The sixth fold line 556 is formed at the boundary between the first left side portion 520 and the first left side connecting portion 523. The seventh fold line 557 is formed at the boundary between the left bottom portion 522 and the first left side connecting portion 523. The eighth fold line 558 is formed at the boundary between the left bottom piece 522 and the second left connecting piece 524. The ninth fold line 559 is formed at the boundary between the second left piece 521 and the second left connecting piece 524.

[0114] Each of the first fold line 551, second fold line 552, third fold line 553, fourth fold line 554, fifth fold line 555, seventh fold line 557, and eighth fold line 558 is formed by recessing from one side of the insulating sheet 50. Each of the sixth fold line 556 and ninth fold line 559 is formed by recessing from the other side of the insulating sheet 50. This allows the left bottom piece 522 to be positioned outside the first left piece 520 and the second left piece 521.

[0115] The insulating sheet 50 further includes a first intersection 540 and a second intersection 541. The first intersection 540 is the intersection with the first fold line 551, the third fold line 553, the fourth fold line 554, the sixth fold line 556, and the seventh fold line 557. The second intersection 541 is the intersection with the second fold line 552, the fourth fold line 554, the fifth fold line 555, the eighth fold line 558, and the ninth fold line 559. The first intersection 540 and the second intersection 541 are located at one corner of a pair of short sides of the bottom surface 500.

[0116] Figure 21 is a perspective view showing the state in which the insulating sheet of the battery according to Embodiment 1 of this technology is bent.

[0117] As shown in Figure 21, the insulating sheet 50 is formed into a bottomed cylindrical shape by folding the first side portion 510, the second side portion 511, the first left side portion 520, the second left side portion 521, the left bottom portion 522, the first left connection portion 523, and the second left connection portion 524 along the first to ninth folding lines 551 to 559 relative to the bottom portion 500.

[0118] Specifically, the first left side portion 520 is folded so that it is on the outside of the second left side portion 521. The first left side portion 520 and the first left side connecting portion 523 are folded so that they are sandwiched between the left bottom portion 522 and the second left side connecting portion 524. As a result, as shown in Figure 19, the insulating sheet 50 forms a first communication passage 530, which is a gap communicating between the inside and outside of the insulating sheet 50, due to the overlapping first left side portion 520, the second left side portion 521, the left bottom portion 522, the first left side connecting portion 523, and the second left side connecting portion 524.

[0119] Figure 22 is a side view of the battery shown in Figure 18, viewed from the direction of arrow XXII. As shown in Figure 22, the insulating sheet 50 further has a first overlapping region 571, a second overlapping region 572, a third overlapping region 573, and a fourth overlapping region 574.

[0120] The first overlapping region 571 is the region between one of the pair of second side walls 104a, 104b and the electrode body 20 where the first left side portion 520 and the second left side portion 521 overlap each other. In this embodiment, the first overlapping region 571 is located between one of the second side walls 104a and the electrode body 20.

[0121] The second overlapping region 572 is the region where the first left side portion 520, the second left side portion 521, and the left bottom portion 522 overlap each other. In this embodiment, the second overlapping region 572 also includes the first left connection portion 523 and the second left connection portion 524 in addition to the first left side portion 520, the second left side portion 521, and the left bottom portion 522.

[0122] The third overlapping region 573 is the region where the first left side portion 520, the left bottom portion 522, and the first left connecting portion 523 overlap. The fourth overlapping region 574 is the region where the second left side portion 521, the left bottom portion 522, and the second left connecting portion 524 overlap.

[0123] The first opening end 531 is located at the end of the exterior body 100 on the opening 101 side of each of the third overlapping region 573 and the fourth overlapping region 574. In this embodiment, the first opening end 531 is located at the end of the second overlapping region 572, the third overlapping region 573, and the fourth overlapping region 574 on the opening 101 side.

[0124] In a direction perpendicular to the bottom surface 500, the shortest distance L between the bottom surface 500 and the first open end 531 is 5 mm or more. This configuration ensures a creepage distance of 5 mm or more between the short-side end of the bottom surface of the electrode body 20 (end 20e, described later) and the outer casing 100. In the insulating sheet 50 according to this embodiment, there are no locations within a radius of 5 mm of each of the first intersection 540 and the second intersection 541 where the inside and outside of the insulating sheet 50 are in communication, thus ensuring a creepage distance of 5 mm or more between the short-side end of the bottom surface of the electrode body 20 (end 20e, described later) and the outer casing 100.

[0125] Figure 23 is a cross-sectional view of the battery shown in Figure 17, viewed from the direction of the arrow XXIII-XXIII. In Figure 23, a cross-section perpendicular to the bottom surface 500 at the intersection of the sixth fold line 556 and the ninth fold line 559 is shown.

[0126] As shown in Figure 23, the insulating sheet 50 is arranged in the following order from the electrode body 20 toward the outer casing 100, around the corner on the bottom 102 side: second left piece 521, second left connection part 524, first left piece 520, first left connection part 523, and left bottom piece 522.

[0127] The first communication passage 530 is located on the shortest path for electrolyte to penetrate from the outside of the insulating sheet 50 to the end of the electrode body 20 that is closest to the ridge of one of the pair of second side walls 104a and 104b on the bottom 102 side of the outer casing 100. In this embodiment, the first communication passage 530 is located on the shortest path for electrolyte 80 to penetrate from the outside of the insulating sheet 50 to the end 20e of the electrode body 20 that is closest to the ridge 104e on the bottom 102 side of the outer casing 100 on one of the second side walls 104a.

[0128] In some cases, a short circuit may be formed between batteries 1 located at both ends of a series-connected battery 1 due to water ingress around battery 1, resulting in a high voltage being applied. In this case, the highest voltage is applied between the end 20e of the electrode body 20 and the ridge portion 104e of the outer casing 100 within the battery 1 located in the short circuit. In the battery 1 according to this embodiment, the first communication passage 530 is located on the shortest possible entry path for the electrolyte 80 that penetrates from the outside of the insulating sheet 50 to the end 20e of the electrode body 20. This ensures that even when a high voltage is applied between the end 20e of the electrode body 20 and the ridge portion 104e of the outer casing 100, a sufficient creepage distance can be maintained between the end 20e of the electrode body 20 and the ridge portion 104e of the outer casing 100. Therefore, partial discharge between the end 20e of the electrode body 20 and the ridge portion 104e of the outer casing 100 can be suppressed.

[0129] Figure 24 is a side view of the battery shown in Figure 18, viewed from the direction of arrow XXIV. As shown in Figures 17, 20, and 24, the insulating sheet 50 includes a first right side portion 525, a second right side portion 526, a right bottom portion 527, a first right side connection portion 528, and a second right side connection portion 529.

[0130] The first right-side portion 525 is bent from the other lateral end of the first side portion 510. In this embodiment, the first right-side portion 525 is bent from the lateral end of the first side portion 510 on the negative electrode side of the battery 1.

[0131] The first right-side portion 525 is positioned between the other of the pair of second side walls 104a, 104b and the electrode body 20. In this embodiment, the first right-side portion 525 is positioned between the other second side wall 104b and the electrode body 20.

[0132] The second right-side portion 526 is bent from the other lateral end of the second side portion 511. In this embodiment, the second right-side portion 526 is bent from the lateral end of the second side portion 511 on the negative electrode side of the battery 1.

[0133] The second right-side portion 526 is positioned between the other of the pair of second side walls 104a, 104b and the electrode body 20, overlapping at least a portion of the first right-side portion 525. In this embodiment, the second right-side portion 526 is positioned between the other second side wall 104b and the electrode body 20.

[0134] The right bottom piece 527 rises from the other side end of the bottom surface 500. In this embodiment, the right bottom piece 527 rises from the side end of the bottom surface 500 on the negative electrode side of the battery 1.

[0135] The right bottom portion 527 is located outside the first right portion 525 and the second right portion 526, which overlap each other, between the other of the pair of second side walls 104a and 104b and the electrode body 20. In this embodiment, the right bottom portion 527 is located between the other second side wall 104b and the electrode body 20, on the other second side wall 104b side than the first right portion 525 and the second right portion 526.

[0136] The first right-side connecting portion 528 is provided continuously with each of the first right-side piece 525 and the right-side bottom piece 527. The first right-side connecting portion 528 is bent at the boundary with each of the first right-side piece 525 and the right-side bottom piece 527 and is sandwiched between the first right-side piece 525 and the right-side bottom piece 527.

[0137] The second right-side connecting portion 529 is provided continuously with each of the second right-side piece 526 and the right-side bottom piece 527. The second right-side connecting portion 529 is bent at the boundary with each of the second right-side piece 526 and the right-side bottom piece 527 and is sandwiched between the second right-side piece 526 and the right-side bottom piece 527.

[0138] The insulating sheet 50 has a 10th fold line 560, an 11th fold line 561, a 12th fold line 562, a 13th fold line 563, a 14th fold line 564, a 15th fold line 565, and a 16th fold line 566 formed on it.

[0139] The 10th fold line 560 is formed at the boundary between the first side portion 510 and the first right side portion 525. The 11th fold line 561 is formed at the boundary between the other of the pair of short sides of the bottom portion 500 and the right bottom portion 527. The 12th fold line 562 is formed at the boundary between the second side portion 511 and the second right side portion 526. The 13th fold line 563 is formed at the boundary between the first right side portion 525 and the first right connection portion 528. The 14th fold line 564 is formed at the boundary between the right bottom portion 527 and the first right connection portion 528. The 15th fold line is formed at the boundary between the right bottom portion 527 and the second right connection portion 529. The 16th fold line 566 is formed at the boundary between the second right side portion 526 and the second right connection portion 529.

[0140] The insulating sheet 50 has a second communication passage 532 that connects the inside and outside of the insulating sheet 50. The second communication passage 532 is composed of a first right side portion 525, a second right side portion 526, a right bottom portion 527, a first right connection portion 528, and a second right connection portion 529. The first communication passage 530 is a gap formed when the first right side portion 525, the second right side portion 526, the right bottom portion 527, the first right connection portion 528, and the second right connection portion 529 are each bent and adjacent to each other, allowing the electrolyte to flow between the inside and outside of the insulating sheet 50 through the second communication passage 532.

[0141] The second connecting passage 532 has a second open end 533. The second open end 533 is located at the end of the exterior body 100 of the first right-side connecting portion 528 and the second right-side connecting portion 529 that is on the opening 101 side. In this embodiment, the second open end 533 is located at the end of the exterior body 100 of the right-side bottom piece portion 527, the first right-side connecting portion 528, and the second right-side connecting portion 529 that is on the opening 101 side.

[0142] The insulating sheet 50 further includes a fifth overlapping region 575, a sixth overlapping region 576, a seventh overlapping region 577, and an eighth overlapping region 578.

[0143] The fifth overlapping region 575 is the region where the first right-side portion 525 and the second right-side portion 526 overlap each other between the other of the pair of second side walls 104a, 104b and the electrode body 20. In this embodiment, the fifth overlapping region 575 is located between the other second side wall 104b and the electrode body 20.

[0144] The sixth overlapping region 576 is the region where the first right-side piece 525, the second right-side piece 526, and the right-side bottom piece 527 overlap each other. In this embodiment, the sixth overlapping region 576 also includes the first right-side connection 528 and the second right-side connection 529 in addition to the first right-side piece 525, the second right-side piece 526, and the right-side bottom piece 527.

[0145] The seventh overlapping region 577 is the region where the first right-side piece 525, the right-side bottom piece 527, and the first right-side connecting portion 528 overlap. The eighth overlapping region 578 is the region where the second right-side piece 526, the right-side bottom piece 527, and the second right-side connecting portion 529 overlap.

[0146] The second opening end 533 is located at the end of the exterior body 100 on the opening 101 side of each of the seventh overlapping region 577 and the eighth overlapping region 578. In this embodiment, the second opening end 533 is located at the end of the sixth overlapping region 576, the seventh overlapping region 577, and the eighth overlapping region 578 on the opening 101 side.

[0147] The insulating sheet 50 further includes a third intersection 542 and a fourth intersection 543. The third intersection 542 is the intersection with the first fold line 551, the tenth fold line 560, the eleventh fold line 561, the thirteenth fold line 563, and the fourteenth fold line 564. The fourth intersection 543 is the intersection with the second fold line 552, the eleventh fold line 561, the twelfth fold line 562, the fifteenth fold line 565, and the sixteenth fold line 566. The third intersection 542 and the fourth intersection 543 are located at the other corner of a pair of short sides of the bottom surface 500.

[0148] The second communication passage 532 is located on the shortest possible entry path for the electrolyte 80 that penetrates from the outside of the insulating sheet 50 to the end of the electrode body 20 that is closest to the bottom 102 side of the outer casing 100 and to the ridge of the other of the pair of second side walls 104a and 104b. In this embodiment, the second communication passage 532 is located on the shortest possible entry path for the electrolyte that penetrates from the outside of the insulating sheet 50 to the end of the electrode body 20 that is closest to the bottom 102 side of the outer casing 100 and to the ridge of the other second side wall 104b.

[0149] The first right side portion 525, the second right side portion 526, the right bottom portion 527, the first right connection portion 528, and the second right connection portion 529, as well as the 10th to 16th folding lines 560 to 566 of the insulating sheet 50, have the same configuration as the first left side portion 520, the second left side portion 521, the left bottom portion 522, the first left connection portion 523, and the second left connection portion 524, as well as the 3rd to 9th folding lines 553 to 559, except for the configuration described above.

[0150] In the battery 1 according to this embodiment, the first communication passage 530 provided in the insulating sheet 50 is located on the shortest path for the electrolyte 80 to penetrate from the outside of the insulating sheet 50 to the end of the electrode body 20 that is closest to the bottom 102 side of the outer casing 100 and to one of the ridges of the pair of second side walls 104a and 104b. As a result, even when a high voltage is applied between the end of the electrode body 20 and the ridge of the outer casing 100, a creepage distance can be secured between the end of the electrode body 20 and the ridge of the outer casing 100, thereby suppressing the occurrence of partial discharge between the end of the electrode body 20 and the ridge of the outer casing 100.

[0151] In the battery 1 according to this embodiment, by ensuring that the shortest distance between the bottom surface 500 and the first open end 531 in a direction perpendicular to the bottom surface 500 is 5 mm or more, the occurrence of partial discharge between the end 20e of the electrode body 20 and the ridge 104e of the outer casing 100 can be suppressed. Note that the shortest distance is not limited to 5 mm, but is appropriately set according to the required creepage distance corresponding to the voltage of the battery 1, etc.

[0152] In the battery 1 according to this embodiment, by making the shortest distance between the first region 311 and the first second side wall 104a in a direction perpendicular to one of the second side walls 104a shorter than the shortest distance between the third region 313 and the first second side wall 104a, a longer insulation distance between the electrode body 20 and the outer casing 100 can be secured at a position close to the open end of the box-shaped insulating sheet 50. The same effect can be obtained in the first region 411, the third region 413 and the other second side wall 104b by having the same configuration as the first region 311, the third region 313 and the first second side wall 104a.

[0153] In the battery 1 according to this embodiment, the electrical connection path to the electrode body 20 of the battery case 10 can be easily configured by using two members, a first positive electrode current collector 300 and a second positive electrode current collector 310, or a first negative electrode current collector 400 and a second negative electrode current collector 410, to connect the tab portion 21 to the positive electrode terminal 230 or the negative electrode terminal 280.

[0154] In the battery 1 according to this embodiment, since multiple wound-type electrode bodies are housed inside the insulating sheet 50 arranged in the battery case 10, the curvature radius of the end on the bottom surface 500 side of the electrode body 20 can be reduced compared to the case where one thick wound-type electrode body is housed, thereby securing a larger area in which the electrolyte 80 can penetrate the electrode body 20, and thus preventing a shortage of electrolyte 80 inside the electrode body 20.

[0155] In the battery 1 according to this embodiment, the first side portion 510 and the bottom portion 500 are continuously connected along the entire length of one of the pair of long sides of the bottom portion 500 of the insulating sheet 50, and the second side portion 511 and the bottom portion 500 are continuously connected along the entire length of the other of the pair of long sides of the bottom portion 500. This allows for continuous insulation between the electrode body 20 and the outer casing 100 at each of the first fold line 551 and the second fold line 552, thereby suppressing the occurrence of partial discharge.

[0156] In the battery 1 according to this embodiment, the bottom surface 500 and the left bottom piece 522 are continuously connected along the entire length of one of the pair of short sides of the bottom surface 500 of the insulating sheet 50, thereby continuously insulating the electrode body 20 and the outer casing 100 at the fourth fold line 554 and suppressing the occurrence of partial discharge.

[0157] In the battery 1 according to this embodiment, the first side portion 510 and the first left side portion 520 of the insulating sheet 50 are continuously connected over the entire length of the area facing the electrode body 20 at the boundary between the first side portion 510 and the first left side portion 520, and the second side portion 511 and the second left side portion 521 are continuously connected over the entire length of the area facing the electrode body 20 at the boundary between the second side portion 511 and the second left side portion 521. As a result, the electrode body 20 and the outer casing 100 are continuously insulated at each of the third bend line 553 and the fifth bend line 555, thereby suppressing the occurrence of partial discharge.

[0158] In the battery 1 according to this embodiment, each of the first fold line 551, second fold line 552, third fold line 553, fourth fold line 554, fifth fold line 555, seventh fold line 557, and eighth fold line 558 is formed by recessing from one side of the insulating sheet 50, and each of the sixth fold line 556 and ninth fold line 559 is formed by recessing from the other side of the insulating sheet 50. As a result, the recessed side can be made the valley side of the fold, and the insulating sheet 50 can be easily folded into a box shape.

[0159] In the battery 1 according to this embodiment, the second communication passage 532 provided in the folded insulating sheet 50 is located on the shortest possible entry path for the electrolyte 80 that enters from the outside of the insulating sheet 50 to the end of the electrode body 20 that is closest to the bottom 102 side of the outer casing 100 and to the other ridge of the pair of second side walls 104a, 104b. As a result, creepage distance between the end of the electrode body 20 and the ridge of the outer casing 100 can be secured, thereby suppressing the occurrence of partial discharge between the end of the electrode body 20 and the ridge of the outer casing 100.

[0160] (Embodiment 2) The following describes the battery according to Embodiment 2 of this technology. Since the configuration of the insulating sheet in the battery according to Embodiment 2 of this technology differs from that of battery 1 according to Embodiment 1 of this technology, the configuration that is the same as that of battery 1 according to Embodiment 1 of this technology will not be repeated in the description.

[0161] Figure 25 is an exploded view showing the configuration of the insulating sheet provided in the battery according to Embodiment 2 of this technology. As shown in Figure 25, the insulating sheet 50A provided in the battery according to this embodiment includes a bottom portion 500, a first side portion 510, a second side portion 511, a first left side portion 520, a second left side portion 521, a left bottom portion 522, a first left connection portion 523A, and a second left connection portion 524A.

[0162] The first left-side connector 523A is provided continuously with the first left-side piece 520 and the left-side bottom piece 522. The second left-side connector 524A is provided continuously with the second left-side piece 521 and the left-side bottom piece 522.

[0163] The insulating sheet 50A has a first fold line 551, a second fold line 552, a third fold line 553, a fourth fold line 554, a fifth fold line 555, a sixth fold line 556A, a seventh fold line 557A, an eighth fold line 558A, and a ninth fold line 559A formed on it.

[0164] The sixth fold line 556A is formed at the boundary between the first left-side piece 520 and the first left-side connection 523A. The sixth fold line 556A includes the short side portion of the first left-side piece 520 on the side of the first left-side connection 523A.

[0165] The seventh fold line 557A is formed at the boundary between the left bottom piece 522 and the first left connection piece 523A. The seventh fold line 557A includes the short side portion of the left bottom piece 522 on the side of the first left connection piece 523A.

[0166] The eighth fold line 558A is formed at the boundary between the left bottom piece 522 and the second left connection piece 524A. The eighth fold line 558A includes the short side portion of the left bottom piece 522 on the side of the second left connection piece 524A.

[0167] The ninth fold line 559A is formed at the boundary between the second left piece 521 and the second left connection 524A. The ninth fold line 559A includes the short side portion of the second left piece 521 on the side of the second left connection 524A.

[0168] In the insulating sheet 50A, a first through-cut portion 523h is formed in the region adjacent to the first left-side connection portion 523A, sandwiched between the sixth fold line 556A and the seventh fold line 557A. A second through-cut portion 524h is formed in the region adjacent to the second left-side connection portion 524A, sandwiched between the eighth fold line 558 and the ninth fold line 559. Note that the first through-cut portion 523h and the second through-cut portion 524h are not limited to a notch shape, and may be structures that allow communication between the inside and outside of the insulating sheet 50, such as slits, through holes, or perforations.

[0169] Each of the first fold line 551, second fold line 552, third fold line 553, fourth fold line 554, fifth fold line 555, seventh fold line 557A, and eighth fold line 558A is formed by recessing from one side of the insulating sheet 50. Each of the sixth fold line 556A and ninth fold line 559A is formed by recessing from the other side of the insulating sheet 50. This allows the left bottom piece 522 to be positioned outside the first left piece 520 and the second left piece 521.

[0170] Figure 26 is a side view showing the internal configuration of a battery according to Embodiment 2 of this technology. As shown in Figure 26, the first left-side connector 523A is bent at the boundary with the first left-side piece 520 and the left-side bottom piece 522, and is sandwiched between the first left-side piece 520 and the left-side bottom piece 522. The second left-side connector 524A is bent at the boundary with the second left-side piece 521 and the left-side bottom piece 522, and is sandwiched between the second left-side piece 521 and the left-side bottom piece 522.

[0171] The insulating sheet 50A has a first communication passage 530A that connects the inside and outside of the insulating sheet 50A. The first communication passage 530A is composed of a first left side portion 520, a second left side portion 521, a left bottom portion 522, a first left connection portion 523A, and a second left connection portion 524A. The first communication passage 530A is a gap formed when each of the first left side portion 520, the second left side portion 521, the left bottom portion 522, the first left connection portion 523A, and the second left connection portion 524A is bent and adjacent to each other, allowing the electrolyte to flow between the inside and outside of the insulating sheet 50A through the first communication passage 530A.

[0172] The first connecting passage 530A has a first open end 531A. The first open end 531A is located in the first connecting passage 530A at the end of the exterior body 100 on the opening 101 side of the first left-side connecting portion 523A and the second left-side connecting portion 524A.

[0173] The insulating sheet 50A further includes a first overlapping region 571, a second overlapping region 572A, a third overlapping region 573A, a fourth overlapping region 574A, a ninth overlapping region 579, and a tenth overlapping region 580.

[0174] The first overlapping region 571 is a region where the first left-side piece portion 520 and the second left-side piece portion 521 overlap each other. The second overlapping region 572A is a region where the first left-side piece portion 520, the second left-side piece portion 521 and the left-side bottom piece portion 522 overlap each other. The third overlapping region 573 is a region where the first left-side piece portion 520, the left-side bottom piece portion 522 and the first left-side connection portion 523A overlap. The fourth overlapping region 574 is a region where the second left-side piece portion 521, the left-side bottom piece portion 522 and the second left-side connection portion 524A overlap.

[0175] The ninth overlapping region 579 is a region where the first left-side piece portion 520 and the left-side bottom piece portion 522 overlap each other. The tenth overlapping region 580 is a region where the second left-side piece portion 521 and the left-side bottom piece portion 522 overlap each other.

[0176] The first opening end 531A is positioned at the position of the end on the opening portion 101 side of the exterior body 100 of each of the third overlapping region 573A and the fourth overlapping region 574A. As shown in FIG. 26, the first opening end 531A in the present embodiment is located on the bottom surface portion 500 side relative to the position where the sixth fold line 556A and the ninth fold line 559A intersect.

[0177] When the width dimension in the direction in which the pair of first side walls 103a, 103b of the electrode body 20 face each other is defined as W, and the height dimension from the bottom surface portion 500 to the first opening end 531A in the direction orthogonal to the bottom surface portion 500 is defined as H, the width dimension W and the height dimension H satisfy the relationship of H<W / 2. Due to this relationship, the first opening end 531A is close to the end portion of the electrode body 20 on the bottom surface portion 500 side.

[0178] Note that the first right-side piece portion 525, the second right-side piece portion 526, the right-side bottom piece portion 527, the first right-side connection portion 528A and the second right-side connection portion 529A, as well as the tenth to twelfth fold lines 560 to 562 and the thirteenth to sixteenth fold lines 563A to 566A in the insulating sheet 50A of the present embodiment have the same configurations as the first left-side piece portion 520, the second left-side piece portion 521, the left-side bottom piece portion 522, the first left-side connection portion 523A and the second left-side connection portion 524A, as well as the third to fifth fold lines 553 to 555 and the sixth to ninth fold lines 556A to 559A.

[0179] In the battery according to the present embodiment, the insulating sheet 50A is formed with the first penetrating cutout portion 523h and the second penetrating cutout portion 524h, so that in the direction orthogonal to the bottom surface portion 500, compared with the case where the first penetrating cutout portion 523h and the second penetrating cutout portion 524h are not formed, the first open end 531A of the first communication passage 530A is located at a position close to the bottom surface portion 500, and thus it is possible to facilitate the penetration of the electrolytic solution from the outer side to the inner side of the insulating sheet 50 while suppressing the occurrence of partial discharge between the end portion 20e of the electrode body 20 and the ridgeline portion 104e of the exterior body 100.

[0180] In the battery 1 according to the present embodiment, the width dimension W in the direction in which the pair of first side walls 103a, 103b of the electrode body 20 face each other and the height dimension H from the bottom surface portion 500 to the first open end 531A in the direction orthogonal to the bottom surface portion 500 satisfy the relationship of H<W / 2, so that the first open end 531A can be brought close to the end portion of the electrode body 20 on the bottom surface portion 500 side, and thus the electrolytic solution can penetrate into the inner side of the insulating sheet 50 even when the amount of the electrolytic solution on the outer side of the insulating sheet 50 is small. Also in the present embodiment, it is preferable that the shortest distance between the bottom surface portion 500 and the first open end 531A in the direction orthogonal to the bottom surface portion 500 is 5 mm or more.

[0181] Although the embodiments of the present technology have been described above, it should be considered that the embodiments disclosed this time are illustrative in all points and not restrictive. The scope of the present technology is indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Description of Reference Signs

[0182] 1 Battery, 10 Battery case, 20 Electrode body, 20e End, 21 Tab, 30 Positive electrode current collector, 40 Negative electrode current collector, 50, 50A Insulating sheet, 60 Positive electrode external conductive member, 70 Negative electrode external conductive member, 80 Electrolyte, 100 Outer casing, 101 Opening, 102 Bottom, 103a, 103b First side wall, 104a, 104b Second side wall, 104e Ridge, 110 Sealing plate, 111 Electrolyte injection hole, 112 Sealing member, 113 Gas discharge valve, 114 Positive electrode terminal mounting hole, 115 Negative electrode terminal mounting hole, 200 Positive electrode plate, 200S Positive electrode base plate, 201 Positive electrode core, 202 Positive electrode active material layer, 203 Positive electrode protective layer, 210 Positive electrode tab group, 220 Positive electrode tab, 221 Tip, 230 Positive electrode terminal, 230A, 280A Crimped part, 231, 281 First external insulating member, 232, 282 Second external insulating member, 232h, 240h, 282h, 290h, 301h, 315, 401h, 415 Through hole, 240, 290 Internal insulating member, 250 Negative electrode plate, 250S Negative electrode base plate, 251 Negative electrode core, 252 Negative electrode active material layer, 260 Negative electrode tab group, 270 Negative electrode tab, 280 Negative electrode terminal, 300 First positive electrode current collector, 301, 401 Base, 302, 402 Current collector connection part, 310 Second positive electrode current collector, 311, 411 1st region, 312,412 2nd region, 313,413 3rd region, 314,414 recess, 316 fuse hole, 320 tab joint, 400 1st negative electrode current collector, 410 2nd negative electrode current collector, 500 bottom part, 510 1st side part, 511 2nd side part, 520 1st left side part, 521 2nd left side piece, 522 Left side bottom piece, 523,523A 1st left side connection, 523h 1st through cutout, 524,524A 2nd left side connection, 524h 2nd through cutout, 525 1st right side piece, 526 2nd right side piece, 527 Right side bottom piece, 528 1st right side connection, 529 2nd right side connection, 530,530A 1st communication passage, 531,531A 532 First open end, 533 Second connecting passage, 533 Second open end, 540 First intersection, 541 Second intersection, 542 Third intersection, 543 Fourth intersection, 551 First bend line, 552 Second bend line, 553 Third bend line, 554 Fourth bend line, 555 Fifth bend line, 556, 556A Sixth bend line, 557, 557A Seventh bend line, 558,558A 8th fold line, 559, 559A 9th fold line, 560 10th fold line, 561 11th fold line, 562 12th fold line, 563 13th fold line, 564 14th fold line, 565 15th fold line, 566 16th fold line, 571 1st overlapping region, 572, 572A 2nd overlapping region, 573, 573A 3rd overlapping region, 574, 574A 4th overlapping region, 575 5th overlapping region, 576 6th overlapping region, 577 7th overlapping region, 578 8th overlapping region, 579 9th overlapping region, 580 10th overlapping region.

Claims

1. An electrode body having a positive electrode plate and a negative electrode plate, A metal casing having an opening and containing the electrode body and electrolyte, A sealing plate that seals the aforementioned opening, A positive terminal electrically connected to the positive electrode plate and attached to the sealing plate, A negative electrode terminal electrically connected to the negative electrode plate and attached to the sealing plate, The system comprises an insulating sheet disposed between the electrode body and the outer casing, The exterior body has a bottom facing the opening, a pair of first side walls erected from the edge of the bottom and facing each other, and a pair of second side walls erected from the edge of the bottom and facing each other, connecting the first side walls. The aforementioned insulating sheet is The bottom portion facing the bottom portion, A first side surface portion is disposed between one of the pair of first side walls and the electrode body, A second side surface portion is disposed between the other of the pair of first side walls and the electrode body, The first left side portion is bent from one end of the side of the first side portion and is positioned between one of the pair of second side walls and the electrode body, The second left side portion is bent from one end of the side of the second side portion, and is positioned between one of the pair of second side walls and the electrode body, with at least a portion overlapping the first left side portion. The left bottom piece rises from one of the side ends of the bottom portion and is located between one of the pair of second side walls and the electrode body, A first left connecting portion is provided continuously with each of the first left side portion and the left bottom portion, and is bent at the boundary with each of the first left side portion and the left bottom portion, and is sandwiched between the first left side portion and the left bottom portion, It includes a second left connecting portion which is provided continuously with each of the second left side portion and the left bottom portion, and is bent at the boundary with each of the second left side portion and the left bottom portion and sandwiched between the second left side portion and the left bottom portion, The shortest path for the electrolyte to penetrate from the outside of the insulating sheet to the end of the electrode body that is closest to the bottom side of the outer casing and to the ridge of one of the pair of second side walls is a path that passes through the outer periphery of the first left connection part, the outer periphery of the left bottom piece part, and the outer periphery of the second left connection part. In any of the outer periphery of the first left-side connecting portion, the outer periphery of the left-side bottom piece, and the outer periphery of the second left-side connecting portion, the shortest distance between the portion on the shortest entry path and the bottom is 5 mm or more. A tab portion is provided on at least one of the positive electrode plate and the negative electrode plate, extending laterally to the electrode body, The system further comprises a current collector connected to the tab portion, The current collector is positioned between the side of the electrode body and one of the pair of second side walls, and includes a first region facing the second side wall, a third region located closer to the sealing plate than the first region and facing the second side wall, and a second region connecting the first region and the third region. A battery in which, in the current collector and the second side wall facing each other, the shortest distance between the first region and the second side wall in a direction perpendicular to the second side wall is shorter than the shortest distance between the third region and the second side wall.

2. The insulating sheet is formed into a bottomed cylindrical shape by being folded, The bottom portion has a rectangular shape with a pair of long sides and a pair of short sides perpendicular to the pair of long sides. The first side surface is connected to one of the pair of long sides of the bottom surface, and a first fold line is formed at the boundary between the bottom surface and the first side surface. The second side surface is connected to the other of the pair of long sides of the bottom surface, and a second fold line is formed at the boundary between the bottom surface and the second side surface. A third fold line is formed at the boundary between the first side portion and the first left side portion. A fourth fold line is formed at the boundary between one of the pair of short sides of the bottom surface and the left bottom piece. A fifth fold line is formed at the boundary between the second side portion and the second left side portion. A sixth fold line is formed at the boundary between the first left piece and the first left connecting piece. A seventh fold line is formed at the boundary between the left bottom portion and the first left connecting portion. An eighth fold line is formed at the boundary between the left bottom portion and the second left connecting portion. A ninth fold line is formed at the boundary between the second left piece and the second left connecting piece. The insulating sheet has, between one of the pair of second side walls and the electrode body, a first overlapping region where the first left side portion and the second left side portion overlap each other, a second overlapping region where the first left side portion, the second left side portion and the left bottom portion overlap each other, a third overlapping region where the first left side portion, the left bottom portion and the first left connection portion overlap, and a fourth overlapping region where the second left side portion, the left bottom portion and the second left connection portion overlap. The first left piece, the second left piece, the left bottom piece, the first left connecting portion, and the second left connecting portion form a first communication passage that connects the inside and outside of the insulating sheet, with the first open end located at the opening-side end of each of the first left connecting portion and the second left connecting portion of the outer casing. The battery according to claim 1, wherein the first open end is located at the end of the outer casing on the opening side of each of the third overlapping region and the fourth overlapping region.

3. The battery according to claim 1 or claim 2, wherein the electrode body is a laminated electrode body including a plurality of positive electrode plates and a plurality of negative electrode plates.

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