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] This technology relates to a battery.

Background Art

[0002] As a prior art document disclosing the configuration of an electrical storage device, there is Japanese Unexamined Patent Application Publication No. 2019-29218 (Patent Document 1). The electrical storage device described in Patent Document 1 includes an electrode body, an insulating holder, and an exterior case. The insulating holder houses the electrode body. The exterior case houses the electrode body 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 is formed in which a high voltage is applied between batteries located at both ends among a plurality of batteries connected in series due to flooding or the like around the battery, a high voltage is applied between the electrode body and the exterior body inside the battery located in the short-circuit path, and through the gap between the electrode body and the exterior body formed by the cut of the insulating sheet, the insulation between the electrode body and the exterior body may be broken and partial discharge may occur.

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

Means for Solving the Problems

[0006] The battery based on this technology includes an electrode body, a metal exterior, a sealing plate, and a single insulating sheet. The electrode body has a positive electrode plate and a negative electrode plate. The exterior has an opening into which the electrode body can be inserted and houses the electrode body and the electrolyte. The sealing plate seals the above-mentioned opening. The insulating sheet is disposed between the electrode body and the exterior. The exterior has a bottom, a pair of first side walls, and a pair of second side walls. The above-mentioned bottom faces the opening. The pair of first side walls stand upright from the edge of the above-mentioned bottom and face each other. The pair of second side walls stand upright from the edge of the above-mentioned bottom and face each other to connect the first side walls to each other. The insulating sheet includes a bottom surface portion, a first side surface portion, a second side surface portion, a first left side piece portion, a second left side piece portion, a left bottom piece portion, a first left side connection portion, and a second left side connection portion. The above-mentioned bottom surface portion faces the above-mentioned bottom. The first side surface portion is disposed between one of the pair of first side walls and the electrode body. The second side surface portion is disposed between the other of the pair of first side walls and the electrode body. The first left side piece portion is bent from one end on the side of the above-mentioned first side surface portion and is disposed between one of the pair of second side walls and the electrode body. The second left side piece portion is bent from one end on the side of the above-mentioned second side surface portion and is disposed between one of the pair of second side walls and the electrode body, overlapping at least partially with the above-mentioned first left side piece portion. The left bottom piece portion rises from one end on the side of the above-mentioned bottom surface portion and is located between one of the pair of second side walls and the electrode body. The first left side connection portion is continuously provided on each of the above-mentioned first left side piece portion and the left bottom piece portion, is bent at the boundary with each of the above-mentioned first left side piece portion and the left bottom piece portion, and is sandwiched between the above-mentioned first left side piece portion and the left bottom piece portion. The second left side connection portion is continuously provided on each of the above-mentioned second left side piece portion and the left bottom piece portion, is bent at the boundary with each of the above-mentioned second left side piece portion and the left bottom piece portion, and is sandwiched between the above-mentioned second left side piece portion and the left bottom piece portion. The insulating sheet has a first opening end at the position of the end on the opening side of the exterior of each of the above-mentioned first left side connection portion and the second left side connection portion by the above-mentioned first left side piece portion, the second left side piece portion, the left bottom piece portion, the first left side connection portion, and the second left side connection portion, and a first communication path is formed to communicate the inside and the outside of the insulating sheet.The first connection path is located on the shortest immersion path of the electrolytic solution that immerses from the outside of the insulating sheet to the end of the electrode body closest to the bottom side of the exterior body and the ridge line portion on one side of the pair of second side walls, and is provided on at least one of the positive electrode plate and the negative electrode plate. The first connection path further includes a tab portion that extends laterally of the electrode body and a current collector connected to the tab portion. The current collector includes a first region facing the second side wall, a third region located closer to the sealing plate side than the first region and facing the second side wall, and a second region connecting the first region and the third region. 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 the direction perpendicular to the second side wall is shorter than the shortest distance between the third region and the second side wall.

Advantages of the Invention

[0007] According to the present technology, the occurrence of partial discharge between the electrode body and the exterior body can be suppressed.

Brief Description of the Drawings

[0008]

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Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present technology will be described. In addition, the same or corresponding parts may be denoted by the same reference numerals, and the description thereof may not be repeated.

[0010] In the embodiments described below, when referring to the number, amount, etc., unless otherwise specified, the scope of the present technology is not necessarily limited to the number, amount, etc. Further, in the following embodiments, each component is not necessarily essential for the present technology, unless otherwise specified.

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

[0012] In this specification, "battery" is not limited to a lithium-ion battery, and may include other batteries such as a nickel-metal hydride battery. In this specification, "electrode" may be a general term for a positive electrode and a negative electrode. Further, "electrode plate" may be a general term for a positive electrode plate and a negative electrode plate.

[0013] In this specification, "storage cell" or "storage module" is not limited to a battery cell or a battery module, and may include a capacitor cell or a capacitor module.

[0014] (Embodiment 1) FIG. 1 is a perspective view showing the configuration of a battery according to Embodiment 1 of the present technology. FIG. 2 is a cross-sectional view of the battery in FIG. 1 as viewed from the direction of the arrow II-II. FIG. 3 is a perspective view showing the internal configuration of the battery excluding the exterior body and the insulating sheet included in the battery according to Embodiment 1 of the present technology.

[0015] As shown in FIGS. 1 to 3, the battery 1 includes 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 exterior body 100 and a sealing plate 110.

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

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

[0018] The bottom 102 faces the opening 101. Each of the pair of first side walls 103a and 103b stands upright from the edge of the bottom 102 and faces each other in parallel. Each of the pair of second side walls 104a and 104b stands upright from the edge of the bottom 102 and faces each other in parallel. Each of the pair of second side walls 104a and 104b connects the pair of first side walls 103a and 103b. The area of each of the pair of first side walls 103a and 103b is larger 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 exterior body 100. The sealing plate 110 is made of, for example, aluminum, an aluminum alloy, iron, or an 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 breaks when the pressure in the battery case 10 reaches a predetermined value or more and discharges the gas in the battery case 10 to the outside.

[0021] The electrode body 20 in the present embodiment is a flat 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 electrode body in which a strip-shaped positive electrode plate and a strip-shaped negative electrode plate are both wound via a strip-shaped separator (not shown).

[0022] As shown in FIGS. 2 and 3, the battery case 10 houses the electrode body 20. Specifically, a plurality of wound electrode bodies are housed together with an electrolyte (not shown) inside an insulating sheet 50 disposed inside the outer package 100 of the battery case 10. The battery case 10 in the present embodiment houses three wound electrode bodies. The electrode body 20 is housed in the outer package 100 with its winding axis parallel to the bottom 102. Note that the number of electrode bodies 20 disposed in the outer package 100 is not limited to three. Further, the electrode body 20 is not limited to a wound electrode body, and may be a stacked electrode body in which a plurality of positive electrode plates and a plurality of negative electrode plates are alternately stacked.

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

[0024] The electrode body 20 is preferably disposed in the outer package 100 with the insulating sheet 50 interposed therebetween in a direction in which 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 FIGS. 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 FIGS. 2 and 3, the positive electrode terminal 230 is electrically connected to the positive electrode tab groups 210 in each of the plurality of 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 include the positive electrode external conductive member 60.

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

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

[0028] The negative electrode terminal 280 is preferably made of metal, more preferably made of copper or a copper alloy. The negative electrode external conductive member 70 is preferably made of metal, more preferably made of aluminum or an aluminum alloy. Note that the region where the negative electrode terminal 280 is connected to the negative electrode current collector 40 may be made of copper or a copper alloy, and the region protruding outside the sealing plate 110 may be 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 tab portion 21. The positive electrode current collector 30 in the present embodiment is connected to the positive electrode tab groups 210. The positive electrode current collector 30 is preferably made of metal, more preferably made of aluminum or an aluminum alloy.

[0030] The positive electrode current collector 30 in the present embodiment 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 an end opposite to the side where the positive electrode terminal 230 is connected. The second positive electrode current collector 310 is connected to the positive electrode tab group 210 on the side opposite to the side connected to the first positive electrode current collector 300. Note that the positive electrode current collector 30 may be composed of one part.

[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. The negative electrode current collector 40 in the present embodiment is connected to the negative electrode tab group 260. The negative electrode current collector 40 is preferably made of metal, and more preferably made of copper or a copper alloy.

[0033] The negative electrode current collector 40 in the present embodiment includes a first negative electrode current collector 400 as an extended 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 an end opposite to the side where 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 connected to the first negative electrode current collector 400. Note that the negative electrode current collector 40 may be composed of one part.

[0034] As shown in FIG. 2, a single insulating sheet 50 is disposed between the electrode body 20 and the exterior body 100. The insulating sheet 50 is preferably a resin sheet. 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, the material of the insulating sheet 50 is preferably PP.

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

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

[0038] FIG. 4 is a front view showing a positive electrode raw plate before the positive electrode plate included in the battery according to Embodiment 1 of the present technology is formed. FIG. 5 is a cross-sectional view of the positive electrode raw plate in FIG. 4 viewed from the direction of the arrow along the line V-V. FIG. 6 is a front view showing the state after the positive electrode plate included in the battery according to Embodiment 1 of the present technology is formed.

[0039] The positive electrode plate is manufactured by processing the positive electrode raw plate 200S. As shown in FIGS. 4 and 5, the positive electrode raw 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 an aluminum foil or an aluminum alloy foil.

[0040] The positive electrode active material layer 202 is formed on the positive electrode core 201 except for one end portion 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 layer slurry with a die coater.

[0041] The positive electrode active material layer slurry is prepared by kneading lithium nickel cobalt manganese composite oxide as a positive electrode active material, polyvinylidene fluoride (PVdF) as a binder, a carbon material as a conductive material, and N-methyl-2-pyrrolidone (NMP) as a dispersion medium so 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 at one end in the width direction of the positive electrode active material layer 202 while being 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, a carbon material as a conductive material, PVdF as a binder, and NMP as a dispersion medium so that the mass ratio of alumina powder: carbon material: PVdF is 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 the NMP contained in the positive electrode active material layer slurry and the positive electrode protective layer slurry. Thereby, the positive electrode active material layer 202 and the positive electrode protective layer 203 are formed. Further, by compressing the positive electrode active material layer 202, a positive electrode raw plate 200S including the positive electrode core 201, the positive electrode active material layer 202, and the positive electrode protective layer 203 is obtained. The positive electrode raw plate 200S is cut into a predetermined shape to obtain a positive electrode plate. Note that the positive electrode raw plate 200S can be cut by laser processing, die processing, or cutter processing by irradiation with energy rays.

[0045] As shown in FIG. 6, a plurality of positive electrode tabs 220 made of the positive electrode core 201 are provided at one end in the width direction of the positive electrode plate 200 formed from the positive electrode raw plate 200S. Considering the state in which the plurality of positive electrode tabs 220 are laminated and connected to the positive electrode current collector 30 as a positive electrode tab group 210, the length or width in the protruding direction of each of the plurality of positive electrode tabs 220 is appropriately adjusted according to the position where each is formed.

[0046] A positive electrode protective layer 203 is provided at the base of each of the plurality of positive electrode tabs 220. Note that the positive electrode tab group 210 may not be provided with the positive electrode protective layer 203.

[0047] Next, the negative electrode plate will be described. FIG. 7 is a front view showing a negative electrode raw plate before the negative electrode plate included in the battery according to Embodiment 1 of the present technology is formed. FIG. 8 is a cross-sectional view of the negative electrode raw plate of FIG. 7 as viewed from the direction of the arrow along line VIII-VIII. FIG. 9 is a front view showing the state of the negative electrode plate included in the battery according to Embodiment 1 of the present technology after being formed.

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

[0049] The negative electrode active material layer 252 is formed on the negative electrode core 251 except for one end on both sides. The negative electrode active material layer 252 is formed by applying a negative electrode active material layer slurry with a die coater.

[0050] The negative electrode active material layer slurry is prepared by kneading graphite as a negative electrode active material, styrene-butadiene rubber (SBR) and carboxymethyl cellulose (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 coated with the negative electrode active material layer slurry is dried to remove the water contained in the negative electrode active material layer slurry. Thereby, the negative electrode active material layer 252 is formed. Further, by compressing the negative electrode active material layer 252, a negative electrode raw plate 250S including the negative electrode core 251 and the negative electrode active material layer 252 is obtained. The negative electrode raw plate 250S is cut into a predetermined shape to obtain a negative electrode plate 250. Note that the negative electrode raw plate 250S can be cut by laser processing, die processing, or cutter processing by irradiation with energy rays.

[0052] As shown in FIG. 9, a plurality of negative electrode tabs 270 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 raw 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 negative electrode tab group 260, the length or width in the protruding direction of each of the plurality of negative electrode tabs 270 is appropriately adjusted according to the position where each is formed.

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

[0054] As shown in FIG. 10, the belt-shaped positive electrode plate 200 and the belt-shaped negative electrode plate 250 produced by the above-described method are wound via a belt-shaped separator (not shown) to produce a flat electrode body 20. The separator preferably has a heat-resistant layer provided on the surface of a polyolefin-based substrate. This heat-resistant layer contains ceramic particles and a binder. As the ceramic particles, for example, aluminum oxide, boehmite, aluminum hydroxide, or titania can be used.

[0055] A positive electrode tab group 210 including a plurality of positive electrode tabs 220 provided on the positive electrode plate 200 is arranged at one end on the side of the electrode body 20 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, more preferably 8 μm or more and 20 μm or less. The number of stacked sheets of the positive electrode tabs 220 in the positive electrode tab group 210 is preferably 10 sheets or more, more preferably 20 sheets or more, and particularly preferably 30 sheets or more.

[0057] On 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 negative electrode tab group 260 including a plurality of negative electrode tabs 270 provided on the negative electrode plate 250 is arranged. Thus, the tab portion 21 is constituted by at least one of the positive electrode tab group 210 and the negative electrode tab group 260. The tab portion 21 in the present embodiment is constituted by 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 FIG. 2, the first region 311 faces one of the second side walls 104a. The tab portion 21 is connected to the first region 311.

[0060] As shown in FIGS. 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 FIG. 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 second positive electrode current collector 310 and one of the second side walls 104a facing each other, the shortest distance between the first region 311 and one of the second side walls 104a in the 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 FIG. 10, a recess 314 is provided in the third region 313. The portion where the recess 314 is provided is thinner than its surroundings. A through hole 315 is provided in the recess 314. In the recess 314, the third region 313 is joined to the first positive current collector 300. A fuse hole 316 can be provided in the second positive current collector 310.

[0064] Similar to the second positive current collector 310, the second negative current collector 410 has a first region 411, a second region 412, and a third region 413. A recess 414 and a through hole 415 are provided in the third region 413. In the recess 414, the third region 413 is joined to the first negative current collector 400.

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

[0066] As shown in FIG. 11, the first region 311 and the positive tab group 210 are joined in a state where the tip 221 of the positive tab group 210 including a plurality of positive tabs 220 is adjacent to the first region 311 of the second positive current collector 310. By this joining, a tab joint portion 320 is formed. As a joining method between the first region 311 and the positive tab group 210, ultrasonic welding, resistance welding, laser welding, or the like can be used.

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

[0068] Similar to the positive electrode tab group 210, the negative electrode tab group 260 is joined to the first region 411 with the first region 411 of the second negative electrode current collector 410 adjacent thereto, thereby forming a tab joint portion. The negative electrode tab group 260 with the tab joint portion formed is curved by being bent. The tip portion of the tab portion 21 that is bent faces at least one of the pair of second side walls 104a and 104b. In the present embodiment, the tip portion faces the other second side wall 104b. Thus, the second negative electrode current collector 410 faces the other second side wall 104b due to the negative electrode tab group 260 being bent.

[0069] In the first region 311 of the second positive electrode current collector 310, the tab joint portion 320 is preferably arranged closer to the base side of the positive electrode tab group 210. With such a configuration, when the positive electrode tab group 210 is bent, a curved shape can be stably formed in the vicinity of the base of the positive electrode tab group 210. The position where the negative electrode tab group 260 is joined in the first region 411 of the second negative electrode current collector 410 is the same as that of the second positive electrode current collector 310.

[0070] As shown in FIG. 2, the end portion of the second positive electrode current collector 310 on the bottom 102 side of the exterior body 100 is preferably located closer to the bottom 102 side than the end portion of the positive electrode tab group 210 on the bottom 102 side of the exterior body 100. With such a configuration, in the process of bending the positive electrode tab group 210, it becomes possible to stably bend the positive electrode tab group 210. The same applies to the lower end portion of the second negative electrode current collector 410 as that of the second positive electrode current collector 310.

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

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

[0073] As shown in FIGS. 13 to 15, in the sealing plate 110, a first external side insulating member 231 is disposed around the positive electrode terminal attachment hole 114 on the surface opposite to the electrode body 20 side, and an internal side insulating member 240 and a first positive current collector 300 are disposed around the positive electrode terminal attachment hole 114 on the surface of the electrode body 20 side.

[0074] The positive electrode terminal 230 is inserted from the outside of the battery 1 into the through hole 232h of the second external side insulating member 232, the positive electrode terminal attachment hole 114 of the sealing plate 110, the through hole 240h of the internal side insulating member 240, and the through hole 301h of the first positive current collector 300. The positive electrode terminal 230 is caulked onto the first positive current collector 300 to form a caulked portion 230A. Note that the caulked portion 230A of the positive electrode terminal 230 may be welded to the first positive current collector 300 after caulking.

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

[0076] Insert the negative electrode terminal 280 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 caulked onto the first negative electrode current collector 400 to form a caulked portion 280A. Note that the caulked portion 280A of the negative electrode terminal 280 may be welded to the first negative electrode current collector 400 after caulking.

[0077] Note that the timing for 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 timing may be after the positive electrode terminal 230 and the negative electrode terminal 280 are fixed to the sealing plate 110, or may be after the electrolyte injection hole 111 of the sealing plate 110 connected to the exterior body 100 is sealed.

[0078] As shown in FIGS. 13 to 15, the first positive electrode current collector 300, which is an extended current collector, has an L-shaped 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 disposed along the sealing plate 110 via the internal insulating member 240 between the electrode body 20 and the sealing plate 110.

[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 disposed between one second side wall 104a of the exterior body 100 and the electrode body 20.

[0080] As shown in FIGS. 13, 14, and 16, the first negative electrode current collector 400, which is an extended current collector, has an L-shaped 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 disposed along the sealing plate 110 via the internal insulating member 290 between the electrode body 20 and the sealing plate 110.

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

[0082] Next, the connection between the first current collector and the second current collector will be described. As shown in FIG. 3, three electrode bodies 20 to which the second positive current collector 310 and the second negative current collector 410 are attached are arranged side by side. At this time, for each of the three electrode bodies 20, the positive tab groups 210 are arranged on the same side, and the negative tab groups 260 are also arranged on the same side.

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

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

[0085] As a connection method for the first positive current collector 300 and the second positive current collector 310, or the first negative current collector 400 and the second negative current collector 410, ultrasonic welding, resistance welding, or laser welding by irradiation with high energy rays can be used. In particular, it is preferable to use laser welding.

[0086] Next, the insertion of the electrode body 20 into the exterior body 100 will be described. As shown in FIG. 2, the electrode body 20 is disposed within an insulating sheet 50 formed in a bag shape or a box shape. The electrode body 20 covered with the insulating sheet 50 is inserted into the exterior body 100. Thereby, a plurality of wound electrode bodies are accommodated within the battery case 10. Next, at the opening 101 of the exterior body 100, the sealing plate 110 is joined by laser welding or the like.

[0087] Thereafter, 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 a sealing member 112. Thereby, the battery 1 is completed. Note that known materials can be used for the positive electrode plate 200, negative electrode plate 250, separator, electrolyte, and materials constituting each mechanism component used in the battery 1 according to the present embodiment.

[0088] Hereinafter, the structure of the insulating sheet 50 in Embodiment 1 of the present technology will be described in detail.

[0089] FIG. 17 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. FIG. 18 is a perspective view showing the configuration of the battery excluding the exterior body included in the battery according to Embodiment 1 of the present technology.

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

[0091] The bottom surface portion 500 is disposed between the electrode body 20 and the bottom portion 102 of the exterior body 100. The bottom surface portion 500 faces the bottom portion 102.

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

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

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

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

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

[0097] The second left side piece portion 521 is disposed between the electrode body 20 and one of the pair of second side walls 104a and 104b, and at least partially overlaps with the first left side piece portion 520. In the present embodiment, the second left side piece portion 521 is disposed between the one second side wall 104a and the electrode body 20.

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

[0099] The left bottom film portion 522 is located outside the first left side piece portion 520 and the second left side piece portion 521 that overlap each other between one of the pair of second side walls 104a and 104b and the electrode body 20. In the present embodiment, the left bottom film portion 522 is located on the side of one of the second side walls 104a with respect to the first left side piece portion 520 and the second left side piece portion 521 between one of the second side walls 104a and the electrode body 20.

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

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

[0102] FIG. 19 is a perspective view showing an enlarged XIX portion of the battery shown in FIG. 18.

[0103] As shown in FIG. 19, a first communication passage 530 that communicates the inside and the outside of the insulating sheet 50 is formed in the insulating sheet 50. The first communication passage 530 is constituted by the first left side piece portion 520, the second left side piece portion 521, the left bottom film portion 522, the first left side connection portion 523, and the second left side connection portion 524. The first communication passage 530 is a gap formed by bending each of the first left side piece portion 520, the second left side piece portion 521, the left bottom film portion 522, the first left side connection portion 523, and the second left side connection portion 524 so as to be adjacent to each other, and the electrolytic solution can flow through the inside and the outside of the insulating sheet 50 through the first communication passage 530.

[0104] The first connection path 530 has a first opening end 531. The first opening end 531 is located at the position of the end on the opening 101 side of the outer casing 100 of each of the first left connection part 523 and the second left connection part 524. The first opening end 531 in the present embodiment is located at the end on the opening 101 side of the outer casing 100 of each of the left bottom film part 522, the first left connection part 523, and the second left connection part 524.

[0105] FIG. 20 is a developed view showing the configuration of an insulating sheet included in the battery according to Embodiment 1 of the present technology.

[0106] As shown in FIGS. 18 and 20, a single insulating sheet 50 is bent to form a bottomed cylindrical shape. As shown in FIG. 20, the bottom surface part 500 has a rectangular shape having a pair of long sides and a pair of short sides orthogonal to the pair of long sides.

[0107] A first side surface part 510 is connected to one of the pair of long sides of the bottom surface part 500. Specifically, the first side surface part 510 and the bottom surface part 500 are continuously connected over the entire length of one of the pair of long sides of the bottom surface part 500.

[0108] A second side surface part 511 is connected to the other of the pair of long sides of the bottom surface part 500. Specifically, the second side surface part 511 and the bottom surface part 500 are continuously connected over the entire length of the other of the pair of long sides of the bottom surface part 500.

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

[0110] The first side surface portion 510 and the first left side piece portion 520 are continuously connected over the entire length of the range facing the electrode body 20 at the boundary therebetween. In the present embodiment, the first side surface portion 510 and the first left side piece portion 520 are continuously connected over the entire length of their boundary. However, a cut or a through hole may be formed at the upper end portion that does not face the electrode body 20 at the boundary between the first side surface portion 510 and the first left side piece portion 520, and there may be a discontinuous portion between the first side surface portion 510 and the first left side piece portion 520.

[0111] The second side surface portion 511 and the second left side piece portion 521 are continuously connected over the entire length of the range facing the electrode body 20 at the boundary therebetween. In the present embodiment, the second side surface portion 511 and the second left side piece portion 521 are continuously connected over the entire length of their boundary. However, a cut or a through hole may be formed at the upper end portion that does not face the electrode body 20 at the boundary between the second side surface portion 511 and the second left side piece portion 521, and there may be a discontinuous portion between the second side surface portion 511 and the second left side piece portion 521.

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

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

[0114] Each of the first folding line 551, the second folding line 552, the third folding line 553, the fourth folding line 554, the fifth folding line 555, the seventh folding line 557, and the eighth folding line 558 is formed by being recessed from one surface side of the insulating sheet 50. Each of the sixth folding line 556 and the ninth folding line 559 is formed by being recessed from the other surface side of the insulating sheet 50. Thereby, the left bottom piece portion 522 can be disposed outside the first left side piece portion 520 and the second left side piece portion 521.

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

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

[0117] As shown in FIG. 21, the insulating sheet 50 is formed into a bottomed cylindrical shape by bending the first side surface portion 510, the second side surface portion 511, the first left side piece portion 520, the second left side piece portion 521, the left bottom piece portion 522, the first left side connection portion 523, and the second left side connection portion 524 with respect to the bottom surface portion 500 at the first to ninth bending lines 551 to 559.

[0118] Specifically, the first left side piece portion 520 is bent so as to be outside the second left side piece portion 521. The first left side piece portion 520 and the first left side connection portion 523 are bent so as to be sandwiched between the left bottom piece portion 522 and the second left side connection portion 524. As a result, as shown in FIG. 19, in the insulating sheet 50, a first communication path 530, which is a gap communicating between the inside and the outside of the insulating sheet 50, is formed by the first left side piece portion 520, the second left side piece portion 521, the left bottom piece portion 522, the first left side connection portion 523, and the second left side connection portion 524 that are folded on top of each other.

[0119] FIG. 22 is a side view of the battery of FIG. 18 as viewed from the direction of arrow XXII. As shown in FIG. 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 a region where the first left side piece portion 520 and the second left side piece portion 521 overlap each other between one of the pair of second side walls 104a and 104b and the electrode body 20. The first overlapping region 571 in the present embodiment is located between one of the second side walls 104a and the electrode body 20.

[0121] The second overlapping region 572 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. In the present embodiment, in the second overlapping region 572, in addition to the first left-side piece portion 520, the second left-side piece portion 521, and the left-side bottom piece portion 522, the first left-side connecting portion 523 and the second left-side connecting portion 524 also overlap.

[0122] 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 connecting portion 523 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 connecting portion 524 overlap.

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

[0124] In the direction orthogonal to the bottom surface portion 500, the shortest distance L between the bottom surface portion 500 and the first opening end 531 is 5 mm or more. With this configuration, it is possible to secure a creepage distance of 5 mm or more between the end portion (end portion 20e to be described later) on the short side of the bottom surface of the electrode body 20 and the exterior body 100. In the insulating sheet 50 according to the present embodiment, there is no location where the inside and the outside of the insulating sheet 50 communicate within a radius of 5 mm for each of the first intersection point 540 and the second intersection point 541, so that it is possible to secure a creepage distance of 5 mm or more between the end portion (end portion 20e to be described later) on the short side of the bottom surface of the electrode body 20 and the exterior body 100.

[0125] FIG. 23 is a cross-sectional view of the battery in FIG. 17 as viewed from the direction of the arrow XXIII-XXIII. In FIG. 23, a cross-section in the direction perpendicular to the bottom surface portion 500 at the position where the sixth folding line 556 and the ninth folding line 559 intersect is shown.

[0126] As shown in FIG. 23, the insulating sheet 50 is arranged in the order of a second left side piece portion 521, a second left side connection portion 524, a first left side piece portion 520, a first left side connection portion 523, and a left side bottom piece portion 522 from the electrode body 20 toward the exterior body 100 around the corner portion on the bottom portion 102 side.

[0127] The first communication path 530 is located on the shortest immersion path of the electrolytic solution that penetrates from the outside of the insulating sheet 50 into the end portion of the electrode body 20 closest to the ridge line portion on one side of the bottom portion 102 side of the exterior body 100 and one of the pair of second side walls 104a, 104b. In the present embodiment, the first communication path 530 is located on the shortest immersion path of the electrolytic solution 80 that penetrates from the outside of the insulating sheet 50 into the end portion 20e of the electrode body 20 closest to the ridge line portion 104e on the bottom portion 102 side of the exterior body 100 and on the side of one of the second side walls 104a.

[0128] In the case where a short - circuit path is formed in which a high voltage is applied between the batteries 1 located at both ends among a plurality of batteries 1 connected in series due to flooding or the like around the battery 1. In this case, the highest voltage is applied between the end portion 20e of the electrode body 20 and the ridge line portion 104e of the exterior body 100 inside the battery 1 located in the short - circuit path. In the battery 1 according to the present embodiment, since the first communication path 530 is located on the shortest immersion path of the electrolytic solution 80 that penetrates from the outside of the insulating sheet 50 into the end portion 20e of the electrode body 20, even when a high voltage is applied between the end portion 20e of the electrode body 20 and the ridge line portion 104e of the exterior body 100, the creepage distance between the end portion 20e of the electrode body 20 and the ridge line portion 104e of the exterior body 100 can be ensured, so that the occurrence of partial discharge between the end portion 20e of the electrode body 20 and the ridge line portion 104e of the exterior body 100 can be suppressed.

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

[0130] The first right-side piece portion 525 is bent from the other end on the side of the first side surface portion 510. The first right-side piece portion 525 in the present embodiment is bent from the end on the side of the first side surface portion 510 on the negative electrode side of the battery 1.

[0131] The first right-side piece portion 525 is disposed between the other one of the pair of second side walls 104a and 104b and the electrode body 20. The first right-side piece portion 525 in the present embodiment is disposed between the other second side wall 104b and the electrode body 20.

[0132] The second right-side piece portion 526 is bent from the other end on the side of the second side surface portion 511. The second right-side piece portion 526 in the present embodiment is bent from the end on the side of the second side surface portion 511 on the negative electrode side of the battery 1.

[0133] The second right-side piece portion 526 is disposed such that at least a part thereof overlaps with the first right-side piece portion 525 between the other one of the pair of second side walls 104a and 104b and the electrode body 20. The second right-side piece portion 526 in the present embodiment is disposed between the other second side wall 104b and the electrode body 20.

[0134] The right-side bottom piece portion 527 rises from the other end on the side of the bottom surface portion 500. The right-side bottom piece portion 527 in the present embodiment rises from the end on the side of the bottom surface portion 500 on the negative electrode side of the battery 1.

[0135] The right-side bottom piece portion 527 is located outside the first right-side piece portion 525 and the second right-side piece portion 526 that overlap each other between the other one of the pair of second side walls 104a and 104b and the electrode body 20. The right-side bottom piece portion 527 in the present embodiment is located on the side of the other second side wall 104b rather than the first right-side piece portion 525 and the second right-side piece portion 526 between the other second side wall 104b and the electrode body 20.

[0136] The first right connection part 528 is provided continuously to each of the first right piece part 525 and the right bottom piece part 527. The first right connection part 528 is bent at the boundary with each of the first right piece part 525 and the right bottom piece part 527, and is sandwiched between the first right piece part 525 and the right bottom piece part 527.

[0137] The second right connection part 529 is provided continuously to each of the second right piece part 526 and the right bottom piece part 527. The second right connection part 529 is bent at the boundary with each of the second right piece part 526 and the right bottom piece part 527, and is sandwiched between the second right piece part 526 and the right bottom piece part 527.

[0138] On the insulating sheet 50, a tenth folding line 560, an eleventh folding line 561, a twelfth folding line 562, a thirteenth folding line 563, a fourteenth folding line 564, a fifteenth folding line 565, and a sixteenth folding line 566 are formed.

[0139] The tenth folding line 560 is formed at the boundary between the first side surface part 510 and the first right piece part 525. The eleventh folding line 561 is formed at the boundary between the other of the pair of short sides of the bottom surface part 500 and the right bottom piece part 527. The twelfth folding line 562 is formed at the boundary between the second side surface part 511 and the second right piece part 526. The thirteenth folding line 563 is formed at the boundary between the first right piece part 525 and the first right connection part 528. The fourteenth folding line 564 is formed at the boundary between the right bottom piece part 527 and the first right connection part 528. The fifteenth folding line is formed at the boundary between the right bottom piece part 527 and the second right connection part 529. The sixteenth folding line 566 is formed at the boundary between the second right piece part 526 and the second right connection part 529.

[0140] The insulating sheet 50 is formed with a second communication path 532 that communicates the inside and the outside of the insulating sheet 50. The second communication path 532 is constituted by a first right-side piece portion 525, a second right-side piece portion 526, a right-side bottom piece portion 527, a first right-side connection portion 528, and a second right-side connection portion 529. The first communication path 530 is a gap formed by bending each of 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 528, and the second right-side connection portion 529 so as to be adjacent to each other, and the electrolytic solution can flow through the inside and the outside of the insulating sheet 50 through the second communication path 532.

[0141] The second communication path 532 has a second opening end 533. The second opening end 533 is located at the end on the opening portion 101 side of the exterior body 100 of each of the first right-side connection portion 528 and the second right-side connection portion 529. The second opening end 533 in the present embodiment is located at the end on the opening portion 101 side of the exterior body 100 of each of the right-side bottom piece portion 527, the first right-side connection portion 528, and the second right-side connection portion 529.

[0142] The insulating sheet 50 further has 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 a region where the first right-side piece portion 525 and the second right-side piece portion 526 overlap each other between the other one of the pair of second side walls 104a and 104b and the electrode body 20. The fifth overlapping region 575 in the present embodiment is located between the other second side wall 104b and the electrode body 20.

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

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

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

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

[0148] The second communication path 532 is located on the shortest immersion path of the electrolytic solution 80 that penetrates from the outside of the insulating sheet 50 to the end portion of the electrode body 20 that is closest to the ridge line portion on the bottom 102 side of the exterior body 100 and on the other side of the pair of second side walls 104a, 104b. In the present embodiment, the second communication path 532 is located on the shortest immersion path of the electrolytic solution that penetrates from the outside of the insulating sheet 50 to the end portion of the electrode body 20 that is closest to the ridge line portion on the bottom 102 side of the exterior body 100 and on the other second side wall 104b side.

[0149] 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 528, the second right-side connection portion 529, and the tenth to sixteenth bending lines 560 to 566 in the insulating sheet 50 have the same configuration 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 523, the second left-side connection portion 524, and the third to ninth bending lines 553 to 559, except for the above-described configuration.

[0150] In the battery 1 according to the present embodiment, since the first communication path 530 provided in the insulating sheet 50 is located on the shortest immersion path of the electrolytic solution 80 that penetrates from the outside of the insulating sheet 50 to the end portion of the electrode body 20 closest to the bottom portion 102 side of the exterior body 100 and the ridge line portion on one side of the pair of second side walls 104a and 104b, even when a high voltage is applied between the end portion of the electrode body 20 and the ridge line portion of the exterior body 100, it is possible to secure the creepage distance between the end portion of the electrode body 20 and the ridge line portion of the exterior body 100. Therefore, it is possible to suppress the occurrence of partial discharge between the end portion of the electrode body 20 and the ridge line portion of the exterior body 100.

[0151] In the battery 1 according to the present embodiment, in the direction orthogonal to the bottom surface portion 500, since the shortest distance between the bottom surface portion 500 and the first opening end 531 is 5 mm or more, it is possible to suppress the occurrence of partial discharge between the end portion 20e of the electrode body 20 and the ridge line portion 104e of the exterior body 100. Note that the above shortest distance is not limited to 5 mm and is appropriately set according to the required creepage distance according to the voltage of the battery 1 and the like.

[0152] In the battery 1 according to the present embodiment, by making the shortest distance between the first region 311 and one of the second side walls 104a in the direction orthogonal to the one second side wall 104a shorter than the shortest distance between the third region 313 and the one second side wall 104a, an insulating distance between the electrode body 20 and the exterior body 100 can be ensured to be long at a position close to the open end of the box-shaped insulating sheet 50. Also 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 one second side wall 104a, the same effect can be obtained.

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

[0154] In the battery 1 according to the present embodiment, since a plurality of wound electrode bodies are accommodated inside the insulating sheet 50 disposed in the battery case 10, compared with the case where one thick wound electrode body is accommodated, the bending radius of the end portion on the bottom surface portion 500 side of the electrode body 20 can be made smaller and a region where the electrolytic solution 80 can penetrate into the electrode body 20 can be ensured to be large, so that it is possible to suppress a shortage of the electrolytic solution 80 inside the electrode body 20.

[0155] In the battery 1 according to the present embodiment, the first side surface portion 510 and the bottom surface portion 500 are continuously connected over the entire length of one of the pair of long sides of the bottom surface portion 500 of the insulating sheet 50, and the second side surface portion 511 and the bottom surface portion 500 are continuously connected over the entire length of the other of the pair of long sides of the bottom surface portion 500, whereby at each of the first folding line 551 and the second folding line 552, the electrode body 20 and the exterior body 100 can be continuously insulated to suppress the occurrence of partial discharge.

[0156] In the battery 1 according to the present embodiment, the bottom surface portion 500 of the insulating sheet 50 and the left bottom piece portion 522 are continuously connected over the entire length of one of the pair of short sides, so that at the fourth bending line 554, the electrode body 20 and the exterior body 100 can be continuously insulated to suppress the occurrence of partial discharge.

[0157] In the battery 1 according to the present embodiment, the first side surface portion 510 and the first left side piece portion 520 are continuously connected over the entire length of the range facing the electrode body 20 at the boundary between the first side surface portion 510 and the first left side piece portion 520, and the second side surface portion 511 and the second left side piece portion 521 are continuously connected over the entire length of the range facing the electrode body 20 at the boundary between the second side surface portion 511 and the second left side piece portion 521. Thus, at each of the third bending line 553 and the fifth bending line 555, the electrode body 20 and the exterior body 100 can be continuously insulated to suppress the occurrence of partial discharge.

[0158] In the battery 1 according to the present embodiment, each of the first bending line 551, the second bending line 552, the third bending line 553, the fourth bending line 554, the fifth bending line 555, the seventh bending line 557, and the eighth bending line 558 is formed by being recessed from one surface side of the insulating sheet 50, and each of the sixth bending line 556 and the ninth bending line 559 is formed by being recessed from the other surface side of the insulating sheet 50. Therefore, the recessed side can be the valley side of the bending, so that the insulating sheet 50 can be easily bent into a box shape.

[0159] In the battery 1 according to the present embodiment, the second communication path 532 provided in the bent insulating sheet 50 is located on the shortest immersion path of the electrolytic solution 80 that penetrates from the outside of the insulating sheet 50 into the end portion of the electrode body 20 that is closest to the bottom portion 102 side of the exterior body 100 and the ridge line portion on the other side of the pair of second side walls 104a, 104b. Thus, the creepage distance between the end portion of the electrode body 20 and the ridge line portion of the exterior body 100 can be ensured, so that the occurrence of partial discharge between the end portion of the electrode body 20 and the ridge line portion of the exterior body 100 can be suppressed.

[0160] (Embodiment 2) The battery according to Embodiment 2 of the present technology will be described below. Since the configuration of the insulating sheet of the battery according to Embodiment 2 of the present technology is different from that of the battery 1 according to Embodiment 1 of the present technology, the description of the same configuration as that of the battery 1 according to Embodiment 1 of the present technology will not be repeated.

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

[0162] The first left side connection portion 523A is continuously provided on each of the first left side piece portion 520 and the left side bottom piece portion 522. The second left side connection portion 524A is continuously provided on each of the second left side piece portion 521 and the left side bottom piece portion 522.

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

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

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

[0166] The eighth folding line 558A is formed at the boundary between the left bottom film portion 522 and the second left connecting portion 524A. The eighth folding line 558A includes the short side portion on the second left connecting portion 524A side in the left bottom film portion 522.

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

[0168] In the insulating sheet 50A, a first through deletion portion 523h is formed in a region adjacent to the first left connecting portion 523A while being sandwiched between the sixth folding line 556A and the seventh folding line 557A. A second through deletion portion 524h is formed in a region adjacent to the second left connecting portion 524A while being sandwiched between the eighth folding line 558 and the ninth folding line 559. Note that the first through deletion portion 523h and the second through deletion portion 524h are not limited to the notch shape, and may have a structure that can communicate the inside and the outside of the insulating sheet 50 such as a slit, a through hole, or a perforation.

[0169] Each of the first folding line 551, the second folding line 552, the third folding line 553, the fourth folding line 554, the fifth folding line 555, the seventh folding line 557A, and the eighth folding line 558A is formed by being recessed from one surface side of the insulating sheet 50. Each of the sixth folding line 556A and the ninth folding line 559A is formed by being recessed from the other surface side of the insulating sheet 50. Thereby, the left bottom film portion 522 can be disposed outside the first left piece portion 520 and the second left piece portion 521.

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

[0171] The insulating sheet 50A is formed with a first communication path 530A that communicates the inside and the outside of the insulating sheet 50A. The first communication path 530A is constituted by the first left piece portion 520, the second left piece portion 521, the left bottom piece portion 522, the first left connection portion 523A, and the second left connection portion 524A. The first communication path 530A is a gap formed by bending each of the first left piece portion 520, the second left piece portion 521, the left bottom piece portion 522, the first left connection portion 523A, and the second left connection portion 524A so as to be adjacent to each other, and the electrolytic solution can flow through the inside and the outside of the insulating sheet 50A through the first communication path 530A.

[0172] The first communication path 530A has a first opening end 531A. The first opening end 531A is located at the end on the opening portion 101 side of the exterior body 100 of each of the first left connection portion 523A and the second left connection portion 524A in the first communication path 530A.

[0173] The insulating sheet 50A further has 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 the 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 the 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 the region where the first left-side piece portion 520, the left-side bottom piece portion 522, and the first left-side connecting portion 523A overlap. The fourth overlapping region 574 is the region where the second left-side piece portion 521, the left-side bottom piece portion 522, and the second left-side connecting portion 524A overlap.

[0175] The ninth overlapping region 579 is the 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 the 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 located at the position of the end on the opening 101 side of the exterior body 100 of each of the third overlapping region 573A and the fourth overlapping region 574A. The first opening end 531A in the present embodiment is located closer to the bottom surface portion 500 side than the position where the sixth bending line 556A and the ninth bending line 559A intersect, as shown in FIG. 26.

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

[0178] In addition, 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 connecting portion 528A, and the second right-side connecting portion 529A, as well as the tenth to twelfth bending lines 560 to 562 and the thirteenth to sixteenth bending lines 563A to 566A in the insulating sheet 50A of the present embodiment, have the same configuration 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 connecting portion 523A, and the second left-side connecting portion 524A, as well as the third to fifth bending lines 553 to 555 and the sixth to ninth bending lines 556A to 559A.

[0179] In the battery according to the present embodiment, since the first through-removed portion 523h and the second through-removed portion 524h are formed in the insulating sheet 50A, in the direction orthogonal to the bottom surface portion 500, compared with the case where the first through-removed portion 523h and the second through-removed portion 524h are not formed, since the first opening end 531A of the first communication path 530A is located at a position close to the bottom surface portion 500, while suppressing the occurrence of partial discharge between the end portion 20e of the electrode body 20 and the ridge line portion 104e of the exterior body 100, it is possible to make the electrolytic solution easily penetrate from the outside to the inside of the insulating sheet 50.

[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 and 103b of the electrode body 20 face each other and the height dimension H from the bottom surface portion 500 to the first opening end 531A in the direction orthogonal to the bottom surface portion 500 satisfy the relationship of H < W / 2. Thus, the first opening end 531A can be brought close to the end portion on the bottom surface portion 500 side of the electrode body 20. Therefore, even when the amount of the electrolytic solution outside the insulating sheet 50 is small, the electrolytic solution can penetrate into the inside of the insulating sheet 50. In the present embodiment as well, in the direction orthogonal to the bottom surface portion 500, it is preferable that the shortest distance between the bottom surface portion 500 and the first opening end 531A is 5 mm or more.

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

Explanation of Reference Numerals

[0182] 1 Battery, 10 Battery case, 20 Electrode body, 20e End portion, 21 Tab portion, 30 Positive current collector, 40 Negative current collector, 50, 50A Insulating sheet, 60 Positive external conductive member, 70 Negative external conductive member, 80 Electrolyte, 100 Outer package, 101 Opening, 102 Bottom portion, 103a, 103b First side wall, 104a, 104b Second side wall, 104e Ridge line portion, 110 Sealing plate, 111 Electrolyte injection hole, 112 Sealing member, 113 Gas discharge valve, 114 Positive terminal attachment hole, 115 Negative terminal attachment hole, 200 Positive electrode plate, 200S Positive electrode raw 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 portion, 230 Positive electrode terminal, 230A, 280A Caulking portion, 231, 281 First external side insulating member, 232, 282 Second external side insulating member, 232h, 240h, 282h, 290h, 301h, 315, 401h, 415 Through hole, 240, 290 Inner side insulating member, 250 Negative electrode plate, 250S Negative electrode raw 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 current collector, 301, 401 Base portion, 302, 402 Current collector connection portion, 310 Second positive current collector, 311, 411 First region, 312, 412 Second region, 313, 413 Third region, 314, 414 Recess, 316 Fuse hole, 320 Tab joint portion, 400 First negative current collector, 410 Second negative current collector, 500 Bottom surface portion, 510 First side surface portion, 511 Second side surface portion, 520 First left side piece portion, 521 Second left side piece portion, 522 Left side bottom piece portion, 523, 523A First left side connection portion, 523h First through hole removal portion, 524, 524A Second left side connection portion, 524h Second through hole removal portion, 525 First right side piece portion, 526 Second right side piece portion, 527 Right side bottom piece portion, 528 First right side connection portion, 529 Second right side connection portion, 530, 530A First communication path, 531, 531A First opening end, 532 Second communication path, 533 Second opening end, 540 First intersection point, 541 Second intersection point, 542 Third intersection point, 543 Fourth intersection point, 551 First folding line, 552 Second folding line, 553 Third folding line, 554 Fourth folding line, 555 Fifth folding line, 556, 556A Sixth folding line, 557, 557A Seventh folding line, 558,558A, the 8th folding line; 559, 559A, the 9th folding line; 560, the 10th folding line; 561, the 11th folding line; 562, the 12th folding line; 563, the 13th folding line; 564, the 14th folding line; 565, the 15th folding line; 566, the 16th folding line; 571, the 1st overlapping area; 572, 572A, the 2nd overlapping area; 573, 573A, the 3rd overlapping area; 574, 574A, the 4th overlapping area; 575, the 5th overlapping area; 576, the 6th overlapping area; 577, the 7th overlapping area; 578, the 8th overlapping area; 579, the 9th overlapping area; 580, the 10th overlapping area.,

Claims

1. An electrode body having a positive electrode plate and a negative electrode plate, A metal exterior body having an opening into which the electrode body can be inserted and housing the electrode body and an electrolytic solution, A sealing plate for sealing the opening, and one insulating sheet disposed between the electrode body and the exterior body, The exterior body has a bottom portion facing the opening, a pair of first side walls standing up from the edge of the bottom portion and facing each other, and a pair of second side walls standing up from the edge of the bottom portion and facing each other to connect the first side walls, The insulating sheet includes a bottom surface portion facing the bottom portion, a first side surface portion disposed between one of the pair of first side walls and the electrode body, a second side surface portion disposed between the other of the pair of first side walls and the electrode body, a first left side piece portion bent from one end on the side of the first side surface portion and disposed between one of the pair of second side walls and the electrode body, a second left side piece portion bent from one end on the side of the second side surface portion and disposed between one of the pair of second side walls and the electrode body, at least partially overlapping the first left side piece portion, a left side bottom piece portion rising from one end on the side of the bottom surface portion and positioned between one of the pair of second side walls and the electrode body, a first left side connecting portion continuously provided on each of the first left side piece portion and the left side bottom piece portion, bent at the boundary with each of the first left side piece portion and the left side bottom piece portion, and sandwiched between the first left side piece portion and the left side bottom piece portion, a second left side connecting portion continuously provided on each of the second left side piece portion and the left side bottom piece portion, bent at the boundary with each of the second left side piece portion and the left side bottom piece portion, and sandwiched between the second left side piece portion and the left side bottom piece portion, and The first left piece part, the second left piece part, the left bottom piece part, the first left connection part, and the second left connection part form a first communication path that has a first opening end at the position of the end on the opening side of the exterior body of each of the first left connection part and the second left connection part, and that connects the inside and the outside of the insulating sheet. The first communication path is located on the shortest immersion path of the electrolytic solution that penetrates from the outside of the insulating sheet into the end of the electrode body that is closest to the bottom side of the exterior body and to the ridge line part on one side of the pair of second side walls. At least one of the positive electrode plate and the negative electrode plate is provided with a tab part that extends laterally of the electrode body, and further includes a current collector connected to the tab part. The current collector includes a first region facing the second side wall, a third region located closer to the sealing plate side than the first region and facing the second side wall, and a second region connecting the first region and the third region. A battery, wherein, in the current collector and the second side wall that face each other, the shortest distance in the direction orthogonal to the second side wall between the first region and 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 in a bottomed cylindrical shape by being bent. The bottom surface part has a rectangular shape having a pair of long sides and a pair of short sides orthogonal to the pair of long sides. The first side surface part is connected to one of the pair of long sides of the bottom surface part, and a first folding line is formed at the boundary between the bottom surface part and the first side surface part. The second side surface part is connected to the other of the pair of long sides of the bottom surface part, and a second folding line is formed at the boundary between the bottom surface part and the second side surface part. A third folding line is formed at the boundary between the first side surface part and the first left piece part. A fourth folding line is formed at the boundary between one of the pair of short sides of the bottom surface part and the left bottom piece part. A fifth bending line is formed at the boundary between the second side surface portion and the second left side piece portion. A sixth bending line is formed at the boundary between the first left side piece portion and the first left side connecting portion. A seventh bending line is formed at the boundary between the left bottom piece portion and the first left side connecting portion. An eighth bending line is formed at the boundary between the left bottom piece portion and the second left side connecting portion. A ninth bending line is formed at the boundary between the second left side piece portion and the second left side connecting portion. The insulating sheet has a first overlapping region where the first left side piece portion and the second left side piece portion overlap each other, a second overlapping region where the first left side piece portion, the second left side piece portion, and the left bottom piece portion overlap each other, a third overlapping region where the first left side piece portion, the left bottom piece portion, and the first left side connecting portion overlap each other, and a fourth overlapping region where the second left side piece portion, the left bottom piece portion, and the second left side connecting portion overlap each other, between one of the pair of second side walls and the electrode body. The battery according to claim 1, wherein the first opening end is located at the position of the end on the opening side of the exterior body in each of the third overlapping region and the fourth overlapping region.

3. The battery according to claim 2, wherein the shortest distance between the bottom surface portion and the first opening end in the direction orthogonal to the bottom surface portion is 5 mm or more.

4. In the insulating sheet, A first through removal portion is formed in a region adjacent to the first left side connecting portion while being sandwiched between the sixth bending line and the seventh bending line. The battery according to claim 3, wherein a second through removal portion is formed in a region adjacent to the second left side connecting portion while being sandwiched between the eighth bending line and the ninth bending line.

5. The electrode body is a wound type electrode body in which both the positive electrode plate and the negative electrode plate are wound. Let the width dimension of the electrode body in the direction in which the pair of first side walls face each other be W. When the height dimension from the bottom surface to the first opening end in the direction orthogonal to the bottom surface is defined as H, The battery according to claim 4, wherein the width dimension W and the height dimension H satisfy the relationship of H < W / 2.

6. Further comprising an extended current collector connected to the current collector, The extended current collector has a base portion disposed between the electrode body and the sealing plate and a current collector connection portion extending from an end of the base portion toward the bottom, The battery according to any one of claims 1 to 5, wherein the current collector connection portion is connected to the third region.

7. The battery according to claim 5, wherein a plurality of the wound electrode bodies are accommodated inside the insulating sheet disposed inside the exterior body.

8. The first side surface portion and the bottom surface portion are continuously connected over the entire length of one of the pair of long sides of the bottom surface portion, The battery according to any one of claims 2 to 5, wherein the second side surface portion and the bottom surface portion are continuously connected over the entire length of the other of the pair of long sides of the bottom surface portion.

9. The battery according to any one of claims 2 to 5, wherein the bottom surface portion and the left bottom piece portion are continuously connected over the entire length of one of the pair of short sides of the bottom surface portion.

10. The first side surface portion and the first left side piece portion are continuously connected over the entire length of the range facing the electrode body at the boundary between the first side surface portion and the first left side piece portion, The battery according to any one of claims 1 to 9, wherein the second side surface portion and the second left side piece portion are continuously connected over the entire length of the range facing the electrode body at the boundary between the second side surface portion and the second left side piece portion.

11. Each of the first folding line, the second folding line, the third folding line, the fourth folding line, the fifth folding line, the seventh folding line, and the eighth folding line is formed by being recessed from one surface side of the insulating sheet. Each of the sixth folding line and the ninth folding line is formed by being recessed from the other surface side of the insulating sheet. The battery according to any one of claims 2 to 5.

12. The insulating sheet is bent from the other end on the side of the first side surface portion and is disposed between the other of the pair of second side walls and the electrode body as a first right side piece portion. is bent from the other end on the side of the second side surface portion and is disposed such that at least a part thereof overlaps with the first right side piece portion between the other of the pair of second side walls and the electrode body as a second right side piece portion. rises from the other end on the side of the bottom surface portion and is located outside the first right side piece portion and the second right side piece portion that overlap each other between the other of the pair of second side walls and the electrode body as a right side bottom piece portion. is continuously provided on each of the first right side piece portion and the right side bottom piece portion, is bent at the boundary with each of the first right side piece portion and the right side bottom piece portion, and is sandwiched between the first right side piece portion and the right side bottom piece portion as a first right side connecting portion. is continuously provided on each of the second right side piece portion and the right side bottom piece portion, is bent at the boundary with each of the second right side piece portion and the right side bottom piece portion, and is sandwiched between the second right side piece portion and the right side bottom piece portion as a second right side connecting portion, and a second communication path is formed by the first right side piece portion, the second right side piece portion, the right side bottom piece portion, the first right side connecting portion, and the second right side connecting portion to communicate the inside and the outside of the insulating sheet and having a second opening end at the position of the end on the opening side of the exterior body of each of the first right side connecting portion and the second right side connecting portion. The second communication path is located on the shortest immersion path of the electrolytic solution that penetrates from the outside of the insulating sheet to the end of the electrode body closest to the ridge line portion on the bottom side of the exterior body and on the other side of the pair of second side walls. The battery according to any one of claims 2 to 5.

13. A tenth bending line is formed at the boundary between the first side surface portion and the first right side piece portion. An eleventh bending line is formed at the boundary between the other of the pair of short sides of the bottom surface portion and the right side bottom piece portion. A twelfth bending line is formed at the boundary between the second side surface portion and the second right side piece portion. A thirteenth bending line is formed at the boundary between the first right side piece portion and the first right side connection portion. A fourteenth bending line is formed at the boundary between the right side bottom piece portion and the first right side connection portion. A fifteenth bending line is formed at the boundary between the right side bottom piece portion and the second right side connection portion. A sixteenth bending line is formed at the boundary between the second right side piece portion and the second right side connection portion. The insulating sheet has a fifth overlapping region where the first right side piece portion and the second right side piece portion overlap each other, a sixth overlapping region where the first right side piece portion, the second right side piece portion, and the right side bottom piece portion overlap each other, a seventh overlapping region where the first right side piece portion, the right side bottom piece portion, and the first right side connection portion overlap, and an eighth overlapping region where the second right side piece portion, the right side bottom piece portion, and the second right side connection portion overlap, between the other of the pair of second side walls and the electrode body. The second opening end is located at the position of the end on the opening side of the exterior body in each of the seventh overlapping region and the eighth overlapping region. The battery according to claim 12.

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