Battery

Abstract

The present invention is provided with: a charge / discharge body 100 in which a positive electrode, a negative electrode, and an insulating member provided between the positive electrode and the negative electrode are laminated; a positive electrode conductive member; and a negative electrode conductive member. The insulating member has insulating properties. The positive electrode has a positive electrode current collector, and a plurality of positive electrode tabs projecting from the positive electrode current collector. The negative electrode has a negative electrode current collector, and a plurality of negative electrode tabs 121b projecting from the negative electrode current collector. The plurality of positive electrode tabs are joined, in a bundled state, to the positive electrode conductive member. The plurality of negative electrode tabs 121b are joined, in a bundled state, to the negative electrode conductive member. The plurality of positive electrode tabs and / or the plurality of negative electrode tabs 121b include, on one side from among the outside and the inside of the charge / discharge body 100, a tab that is wider than a tab on the other side.

Description

Battery

[0001] The present invention relates to a battery.

[0002] A battery including a charge-discharge body (electrode body) having tabs and a conductive member (current collector) joined to the tabs is known (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2024-53888

[0004] There is a demand for a battery in which the tabs and conductive members such as current collectors and electrode terminals are sufficiently joined.

[0005] A battery according to an aspect of the present invention includes a charge-discharge body in which a positive electrode, a negative electrode, and an insulating member provided between the positive electrode and the negative electrode are laminated, a positive electrode conductive member, and a negative electrode conductive member. The insulating member has insulating properties. The positive electrode has a positive electrode current collector and a plurality of positive electrode tabs that are a plurality of tabs protruding from the positive electrode current collector. The negative electrode has a negative electrode current collector and a plurality of negative electrode tabs that are a plurality of tabs protruding from the negative electrode current collector. The plurality of positive electrode tabs are joined to the positive electrode conductive member in a bundled state, and the plurality of negative electrode tabs are joined to the negative electrode conductive member in a bundled state. At least one of the plurality of positive electrode tabs and the plurality of negative electrode tabs includes the tab that is wider than the other tab on one side inside and outside the charge-discharge body.

[0006] According to the present invention, a battery in which the tabs and the conductive member are sufficiently joined can be obtained.

[0007] A perspective view showing the battery 1 of the first embodiment. A perspective view showing a cross-sectional view of the components around the negative electrode terminal 420 of the battery 1. A side view showing the components of Figure 2. A perspective view showing a cross-sectional view of the components around the positive electrode terminal 410 of the battery 1. A side view showing the components of Figure 4. A perspective view showing the battery 1 partially disassembled. A perspective view showing the charge / discharge body 100 of the battery 1. A side view showing a cross-sectional view of a part of the charge / discharge body 100 of Figure 7. A side view showing a cross-sectional view of a part of the charge / discharge body 1100 of a modified example. A perspective view showing the components around the negative electrode terminal 420 of the battery 1 disassembled. A perspective view showing the components around the opening valve 530 and sealing plug 540 of the battery 1 disassembled. A perspective view showing the components around the positive electrode terminal 410 of the battery 1 disassembled. A perspective view of the charge / discharge body 100 according to the first embodiment, in a state where there is no misalignment of the plurality of negative electrode tabs 121b. A perspective view of the charge / discharge body 100 according to the first embodiment, in a state where there is misalignment of multiple negative electrode tabs 121b. A perspective view showing the joint between the multiple negative electrode tabs 121b and the negative electrode current collector plate 220. A schematic plan view of the charge / discharge body 100 in a state where there is no misalignment of multiple negative electrode tabs 121b. A schematic plan view of the charge / discharge body 100 in a state where there is misalignment of multiple negative electrode tabs 121b. A schematic plan view of a charge / discharge body 1000 according to a comparative example of this embodiment in a state where there is no misalignment of multiple negative electrode tabs 1021b. A schematic plan view of a charge / discharge body 1000 according to a comparative example of this embodiment in a state where there is misalignment of multiple negative electrode tabs 1021b. A perspective view of the charge / discharge body 800 according to the second embodiment, in a state where there is no misalignment of multiple negative electrode tabs 821b. A perspective view of the charge / discharge body 800 according to the second embodiment, in a state in which the positional displacement of the multiple negative electrode tabs 821b has occurred. A perspective view of the charge / discharge body 900 according to the third embodiment, in a state in which the positional displacement of the multiple negative electrode tabs 121b has not occurred. A perspective view of the charge / discharge body 900 according to the third embodiment, in a state in which the positional displacement of the multiple negative electrode tabs 121b has occurred.

[0008] Embodiments for carrying out the present invention will be described with reference to the drawings. In order to facilitate understanding of each embodiment, the size and proportions of the components may be exaggerated in each drawing. In each drawing, the same reference numerals are assigned to the same components. In each drawing, the longitudinal direction X, the short direction Y, and the height direction Z of the battery 1 are indicated by arrows. In each drawing, the longitudinal direction X, the short direction Y, and the height direction Z of the battery 1 indicate the relative positional relationship within the same drawing. That is, if the battery 1 is rotated 180 degrees and the top and bottom surfaces are reversed, or if the battery 1 is rotated 90 degrees and the top surface is positioned as a side surface, the longitudinal direction X, the short direction Y, and the height direction Z of the battery 1 will change.

[0009] (Configuration of Battery 1 in the First Embodiment) The configuration of Battery 1 will be described with reference to Figures 1 to 16B.

[0010] Figure 1 is a perspective view showing a battery 1 of the first embodiment. Figure 2 is a perspective view showing a cross-sectional view of the components around the negative electrode terminal 420 of the battery 1. Figure 3 is a side view showing the components of Figure 2. Figure 4 is a perspective view showing a cross-sectional view of the components around the positive electrode terminal 410 of the battery 1. Figure 5 is a side view showing the components of Figure 4. Figure 6 is a perspective view showing the battery 1 partially disassembled. Figure 7 is a perspective view showing the charge / discharge body 100 of the battery 1. Figure 8 is a side view showing a cross-sectional view of a part of the charge / discharge body 100 of Figure 7. Figure 9 is a side view showing a cross-sectional view of a part of a modified charge / discharge body 1100. Figure 10 is a perspective view showing a disassembled view of the components around the negative electrode terminal 420 of the battery 1. Figure 11 is a perspective view showing a disassembled view of the components around the opening valve 530 and sealing plug 540 of the battery 1. Figure 12 is a perspective view showing a disassembled view of the components around the positive electrode terminal 410 of the battery 1.

[0011] The battery 1 includes a charge / discharge unit 100 for charging and discharging electricity, a current collector 200 connected to the charge / discharge unit 100, a current interrupter 300 connected to the current collector 200, electrode terminals 400 connected to the current collector 200 or the current interrupter 300, an outer casing 500 in which the components of the battery 1 are housed or attached, an insulator 600 that insulates the components of the battery 1 from the outer casing 500, and a sealant 700 that seals the components of the battery 1 from the outer casing 500.

[0012] The charge / discharge unit 100 charges and discharges electricity. The charge / discharge unit 100 shown in Figures 2 to 8 includes a positive electrode 110, a negative electrode 120, a separator 130, and an electrolyte 140. The charge / discharge unit 100 is constructed by winding a rectangular parallelepiped shape a component (sheet structure) in which a long sheet-shaped positive electrode 110, a long sheet-shaped first separator 130, a long sheet-shaped negative electrode 120, and a long sheet-shaped second separator 130 are stacked in that order.

[0013] The positive electrode 110 includes a long positive electrode current collector layer 111 and a positive electrode active material layer 112 bonded to both sides of the positive electrode current collector layer 111. The positive electrode current collector layer 111 includes a positive electrode current collector (positive electrode current collector foil) 111a and a plurality of tabs (hereinafter also referred to as positive electrode tabs 111b). The positive electrode active material layer 112 is bonded to the positive electrode current collector 111a. As shown in Figure 8, the positive electrode active material layer 112 faces, for example, the entire area along the short direction of the positive electrode current collector 111a. The positive electrode tabs 111b protrude from the side edge 111c along the longitudinal direction of the positive electrode current collector 111a in the short direction of the positive electrode current collector 111a. The positive electrode tabs 111b are formed integrally with the positive electrode current collector 111a. Multiple positive electrode tabs 111b are formed on a single positive electrode current collector 111a. The positive electrode 110 may be configured such that a positive electrode active material layer 112 is bonded to only one side of the positive electrode current collector layer 111. The positive electrode current collector layer 111 is formed of, for example, aluminum or an aluminum alloy. The positive electrode active material layer 112 contains a positive electrode active material composed of a lithium-containing composite oxide, a binder, and a conductive additive. Examples of lithium-containing composite oxides include metallic elements such as nickel (Ni), cobalt (Co), and manganese (Mn), and lithium (Li).

[0014] The negative electrode 120 includes a long negative electrode current collector layer 121 and a negative electrode active material layer 122 bonded to both sides of the negative electrode current collector layer 121. The negative electrode current collector layer 121 includes a negative electrode current collector (negative electrode current collector foil) 121a and a plurality of tabs (hereinafter also referred to as negative electrode tabs 121b). As shown in Figure 8, the negative electrode current collector 121a of the negative electrode 120 has a longer width in the short direction compared to the positive electrode current collector 111a of the positive electrode 110. Both ends of the positive electrode current collector 111a of the positive electrode 110 are located within the range of the negative electrode current collector 121a of the negative electrode 120 in the short direction, via a separator 130. The negative electrode active material layer 122 is bonded to the negative electrode current collector 121a. The negative electrode active material layer 122 faces, for example, the entire area along the short direction of the negative electrode current collector 121a. The negative electrode tab 121b protrudes from the side edge 121c along the longitudinal direction of the negative electrode current collector 121a in the short direction of the negative electrode current collector 121a. When stacked with the positive electrode 110 via the separator 130, the negative electrode tab 121b protrudes in the same direction as the positive electrode tab 111b of the positive electrode 110. When stacked with the positive electrode 110 via the separator 130, the negative electrode tab 121b is separated from the positive electrode tab 111b of the positive electrode 110. The negative electrode tab 121b is formed integrally with the negative electrode current collector 121a. Multiple negative electrode tabs 121b are formed on a single negative electrode current collector 121a. The negative electrode 120 may be configured such that the negative electrode active material layer 122 is bonded to only one side of the negative electrode current collector layer 121. The negative electrode current collector layer 121 is formed of, for example, copper or a copper alloy. The negative electrode active material layer 122 contains a negative electrode active material composed of a carbon-based material, a binder, and a conductive additive. For example, graphite is used as the carbon-based material.

[0015] The separator 130 is an insulating material having insulating properties. The separator 130 is provided between the positive electrode 110 and the negative electrode 120. The separator 130 allows lithium ions to pass through while insulating the space between the positive electrode 110 and the negative electrode 120. The separator 130 is formed in an elongated shape. As shown in Figure 8, the separator 130 has a longer width in the short direction compared to the positive electrode current collector 111a of the positive electrode 110 and the negative electrode current collector 121a of the negative electrode 120. Both ends of the positive electrode current collector 111a of the positive electrode 110 and both ends of the negative electrode current collector 121a of the negative electrode 120 are located within the range of the separator 130 in the short direction. The separator 130 is made of a porous material. The separator 130 is made of polyethylene (PE) or polypropylene (PP). A different insulating material may be used instead of the separator 130. The insulating material may be provided on the side of the positive electrode 110 facing the negative electrode 120. The insulating material may also be provided on the side of the negative electrode 120 facing the positive electrode 110. The insulating material may be heat-resistant. In such a configuration, the separator 130 is not essential.

[0016] The electrolyte 140 facilitates the flow of lithium ions between the positive electrode 110 and the negative electrode 120. The electrolyte 140 is also called an electrolyte solution. The electrolyte 140 contains a solvent and a solute. The electrolyte 140 may also contain additives. The solvent may include, for example, an organic solvent. For example, a carbonate ester such as ethylene carbonate is used as the organic solvent. The solute may include, for example, a lithium salt. For example, lithium hexafluoride phosphate (LiPF) is used as the lithium salt. ６ ) is used.

[0017] A modified example of the charge / discharge body 100, the charge / discharge body 1100, will be described with reference to Figure 9. The configuration of the positive electrode 1110 in the charge / discharge body 1100 differs from the configuration of the positive electrode 110 in the charge / discharge body 100. In the configuration of the charge / discharge body 1100, the same reference numerals are used for components that are the same as those in the charge / discharge body 100, and their explanation is omitted. The positive electrode active material layer 1112 of the charge / discharge body 1100 faces the positive electrode current collector 111a, excluding both ends along the short direction. The heat-resistant insulating layer 1113 of the charge / discharge body 1100 is joined to both ends along the short direction of the positive electrode current collector 111a and to the base end of the positive electrode tab 111b.

[0018] Thus, the charge / discharge bodies 100 and 1100 are wound bodies in which at least the positive electrodes 110 and 1110 and the negative electrode 120 are wound around an insulating member (separator 130).

[0019] The current collector 200 is connected to the charge / discharge unit 100. The current collector 200 is also called a current collector plate. The current collector 200 is a conductive member that electrically connects the charge / discharge unit 100 and the electrode terminals 400. The current collector 200 shown in Figures 2 to 5, 10 and 12 includes a positive electrode current collector plate 210 and a negative electrode current collector plate 220.

[0020] The positive electrode current collector plate 210 is a positive electrode conductive member that connects the positive electrode tab 111b of the charge / discharge body 100 and the positive electrode terminal 410 via the current interrupter 300. The positive electrode current collector plate 210 includes a rectangular plate-shaped first base portion 210a, a rectangular plate-shaped second base portion 210b, and a connecting portion 210c that connects the first base portion 210a and the second base portion 210b in a stepped manner with different heights. A recess 210d is formed on the upper surface of the second base portion 210b, which is configured to be thinner than the second base portion 210b. In the center of the recess 210d, a ring-shaped recess is formed, creating a fragile portion 210e that partially weakens the recess 210d. The positive electrode current collector plate 210 is made of, for example, aluminum or an aluminum alloy.

[0021] The negative electrode current collector plate 220 is a negative electrode conductive member that connects the negative electrode tab 121b of the charge / discharge body 100 with the negative electrode terminal 420. The negative electrode current collector plate 220 includes a rectangular plate-shaped base portion 220a and an insertion hole 220b that penetrates the base portion 220a. The insertion portion 420b of the negative electrode terminal 420 is inserted into the insertion hole 220b of the negative electrode current collector plate 220. The negative electrode current collector plate 220 is formed of, for example, copper or a copper alloy.

[0022] The current interrupter 300 maintains contact with the positive electrode current collector plate 210 when the internal pressure of the battery 1 is within a predetermined value, thereby maintaining the current path between the current collector 200 and the positive electrode terminal 410. On the other hand, when the internal pressure of the battery 1 rises above a predetermined value, the current interrupter 300 separates from the positive electrode current collector plate 210, thereby opening the current path between the current collector 200 and the positive electrode terminal 410 and interrupting the current path between the current collector 200 and the positive electrode terminal 410. The current interrupter 300 is also called a current interruption member (CID: Current Interrupt Device). In the battery 1, the current interrupter 300 is not an essential component. The current interrupter 300 shown in Figures 4, 5 and 12 includes a diaphragm 310, a conductive member 320, and a pair of support bases 330.

[0023] The diaphragm 310 includes a curved cylindrical body portion 310a, a disc-shaped first joint portion 310b provided on the tip side of the body portion 310a, and a ring-shaped second joint portion 310c provided on the base end side of the body portion 310a. The first joint portion 310b is joined to a recess 210d of the positive electrode current collector plate 210. The second joint portion 310c is joined to the conductive member 320. When the internal pressure of the battery 1 rises above a predetermined value, the first joint portion 310b of the diaphragm 310 deforms and ruptures toward the outside of the battery 1 together with the recess 210d of the positive electrode current collector plate 210. As a result, the diaphragm 310 separates from the positive electrode current collector plate 210. Therefore, the current path between the current collector 200 and the positive electrode terminal 410 is interrupted. The diaphragm 310 is formed of, for example, aluminum or an aluminum alloy.

[0024] The conductive member 320 is formed in a cylindrical shape. The conductive member 320 includes a disc-shaped base portion 320a and an insertion hole 320b opening in the center of the base portion 320a. The positive electrode side insulating plate 620 is joined to the upper surface of the conductive member 320. The second joint portion 310c of the diaphragm 310 is joined to the outer edge of the lower surface of the conductive member 320. The conductive member 320 is formed of, for example, aluminum or an aluminum alloy.

[0025] The support base 330 includes a rectangular main body portion 330a extending in the short direction of the battery 1, and leg portions 330b extending downward from both sides in the longitudinal direction of the main body portion 330a. One support base 330 is provided at each end of the diaphragm 310 along the longitudinal direction of the battery 1. The main body portion 330a is attached to the positive electrode side insulating plate 620. The leg portions 330b are attached to the second base portion 210b of the positive electrode current collector plate 210. The support base 330 is formed of, for example, an insulating resin.

[0026] The plug 340 is provided in the through-hole 410d of the positive terminal 410. The plug 340 detaches from the through-hole 410d when the internal pressure of the battery 1 increases. Specifically, when the diaphragm 310 deforms outward from the battery 1 and the pressure in the space between the diaphragm 310 and the positive terminal 410 increases, the plug 340 is discharged outward from the through-hole 410d of the positive terminal 410. The plug 340 is made of resin and molded into the through-hole 410d of the positive terminal 410.

[0027] The electrode terminals 400 are connected to the current collector 200 or the current interrupter 300. The electrode terminals 400 shown in Figures 1 to 6, 10, and 12 include a positive electrode terminal 410 and a negative electrode terminal 420.

[0028] The positive terminal 410 is connected to the conductive member 320 of the current interrupter 300, for example, as shown in Figure 5. The positive terminal 410 includes a rectangular plate-shaped base 410a, a cylindrical insertion portion 410b protruding downward from the base 410a in Figure 4, and a cylindrical joint portion 410c protruding downward from the outer circumference of the base 410a in Figure 4. The positive terminal 410 includes a through portion 410d that penetrates the base 410a and the insertion portion 410b. The base 410a is in contact with the base 720a of the positive side second gasket 720. The insertion portion 410b is inserted into the insertion hole 720b of the positive electrode side second gasket 720, the positive electrode side insertion hole 520a of the cover 520, the insertion hole 620b of the positive electrode side insulating plate 620, and the insertion hole 320b of the conductive member 320. As shown in Figures 5 and 12, the joint portion 410c protrudes downward from the insertion hole 320b of the conductive member 320 and is expanded radially outward to join with the conductive member 320. In other words, the joint portion 410c is crimped to the conductive member 320. Furthermore, the joint portion 410c is welded to the conductive member 320. The plug 340 of the current interrupter 300 is inserted into the through portion 410d. In this configuration, the busbar that is joined to the positive electrode terminal 410 is provided with a through hole to prevent interference with the plug 340. Alternatively, in such a configuration, the busbar connected to the positive terminal 410 is positioned to prevent interference with the plug 340. On the other hand, if the battery 1 is not provided with a current interrupter 300, it is not necessary to provide a through-hole 410d in the positive terminal 410. That is, if the battery 1 is not provided with a current interrupter 300, the busbar connected to the positive terminal 410 does not need to have a through-hole. The positive terminal 410 is formed of, for example, aluminum or an aluminum alloy.

[0029] The negative electrode terminal 420 is connected to the negative electrode current collector plate 220, for example, as shown in Figure 3. As shown in Figures 3 and 10, the negative electrode terminal 420 includes a rectangular plate-shaped base portion 420a, a cylindrical insertion portion 420b protruding downward from the base portion 420a in Figure 3, and a cylindrical joint portion 420c protruding downward from the outer circumference of the base portion 420a in Figure 3. The base portion 420a is in contact with the base portion 740a of the negative electrode side second gasket 740. The insertion portion 420b is inserted into the insertion hole 740b of the negative electrode side second gasket 740, the negative electrode side insertion hole 520b of the cover 520, the insertion hole 630b of the negative electrode side insulating plate 630, and the insertion hole 220b of the negative electrode current collector plate 220. As shown in Figures 3 and 10, the joint portion 420c protrudes downward from the insertion hole 220b of the negative electrode current collector plate 220 and is expanded radially outward to join with the negative electrode current collector plate 220. In other words, the joint portion 420c is crimped to the negative electrode current collector plate 220. Furthermore, the joint portion 420c is welded to the negative electrode current collector plate 220. The negative electrode terminal 420 is formed of, for example, copper or a copper alloy.

[0030] The outer casing 500 houses or mounts the components of the battery 1. The outer casing 500 shown in Figures 1 to 6 and Figures 10 to 12 includes a container 510, a lid 520, a detachable valve 530, and a sealing plug 540.

[0031] The container 510 houses the charge / discharge unit 100, etc. The container 510 is made of a rectangular metal can. The container 510 includes an opening 510a that opens along the longitudinal direction and a housing section 510b that is connected to the opening 510a. The container 510 is made of, for example, aluminum or an aluminum alloy.

[0032] The lid 520 seals the opening 510a of the container 510. The container 510 is formed from a long, plate-shaped metal sheet. The lid 520 has a positive electrode insertion hole 520a, which is a circular through-hole, at one end in the longitudinal direction X. The insertion portion 410b of the positive electrode terminal 410 and the positive electrode side first gasket 710 of the sealing body 700 are inserted into the positive electrode insertion hole 520a. The lid 520 has a negative electrode insertion hole 520b, which is a circular through-hole, at the other end in the longitudinal direction X. The insertion portion 420b of the negative electrode terminal 420 and the negative electrode side first gasket 730 of the sealing body 700 are inserted into the negative electrode insertion hole 520b. Between the positive electrode insertion hole 520a and the negative electrode insertion hole 520b, the lid 520 has a liquid injection insertion hole 520c, which is a circular through-hole. The insertion portion 540b of the sealing stopper 540 is inserted into the injection hole 520c for liquid injection. The lid 520 is welded to the container 510. The lid 520 is made of, for example, aluminum or an aluminum alloy.

[0033] The cleavage valve 530 is provided on the lid 520, as shown in Figure 11. When the internal pressure of the battery 1 reaches a predetermined value, the cleavage valve 530 cleaves outward from the battery, allowing the internal pressure of the battery 1 to become atmospheric pressure. The cleavage valve 530 is formed, for example, in a circular shape. The cleavage valve 530 is formed to be thinner than the lid 520. The cleavage valve 530 has a groove that serves as a reference for cleavage. The cleavage valve 530 is formed integrally with the lid 520. The cleavage valve 530 may be formed separately from the lid 520 and then welded in an annular manner to a through hole provided in the lid 520.

[0034] As shown in Figure 6, the sealing plug 540 seals the liquid injection hole 520c of the lid 520. The sealing plug 540 is formed in a cylindrical shape. As shown in Figure 11, the sealing plug 540 includes a head 540a with a relatively large outer diameter and an insertion portion 540b that is continuous with the head 540a and has a relatively smaller outer diameter. The head 540a of the sealing plug 540 is welded to the lid 520. The insertion portion 540b is inserted into the liquid injection hole 520c. The sealing plug 540 is formed of, for example, aluminum or an aluminum alloy.

[0035] The insulator 600 insulates the components of the battery 1 from the outer casing 500. The insulator 600 shown in Figures 2 to 5, 10 and 12 includes an insulating cover 610, a positive electrode side insulating plate 620, and a negative electrode side insulating plate 630.

[0036] The insulating cover 610 covers the charge / discharge element 100. The insulating cover 610 exposes one side 100a of the charge / discharge element 100 to the outside, while covering the rest of the charge / discharge element 100. The insulating cover 610 is formed, for example, in a pentahedral shape and is constructed by folding into a box shape. The insulating cover 610 is made of, for example, polypropylene.

[0037] The positive electrode side insulating plate 620 insulates the positive electrode current collector plate 210 and the conductive member 320 from the lid 520. The positive electrode side insulating plate 620 includes a rectangular plate-shaped base portion 620a, an insertion hole 620b that penetrates the base portion 620a, and a protrusion 620c that surrounds the side edge of the base portion 620a in an annular shape and protrudes away from the lid 520. The positive electrode side insulating plate 620 houses the positive electrode current collector plate 210 and the conductive member 320, etc., in the space formed by the base portion 620a and the protrusion 620c. The insertion portion 410b of the positive electrode terminal 410 is inserted into the insertion hole 620b. The positive electrode side insulating plate 620 is formed of, for example, an insulating resin.

[0038] The negative electrode side insulating plate 630 insulates the negative electrode current collector plate 220 from the cover 520. The negative electrode side insulating plate 630 includes a rectangular plate-shaped base portion 630a, an insertion hole 630b that penetrates the base portion 630a, and a protrusion 630c that surrounds the side edge of the base portion 630a in an annular shape and protrudes away from the cover 520. The negative electrode current collector plate 220 is housed in the space formed by the base portion 630a and the protrusion 630c of the negative electrode side insulating plate 630. The insertion portion 420b of the negative electrode terminal 420 is inserted into the insertion hole 630b. The negative electrode side insulating plate 630 is formed of, for example, an insulating resin.

[0039] The sealing body 700 seals the components of the battery 1 and the outer casing 500. The sealing body 700 shown in Figures 2 to 5, 10 and 12 includes a positive electrode side first gasket 710, a positive electrode side second gasket 720, a negative electrode side first gasket 730, and a negative electrode side second gasket 740.

[0040] The positive electrode side first gasket 710 seals the positive electrode current collector plate 210 and the cover 520, thereby sealing the outer casing 500. The positive electrode side first gasket 710 is formed in a cylindrical shape. As shown in Figure 12, the positive electrode side first gasket 710 includes a first insertion portion 710a with a relatively large outer diameter, a second insertion portion 710b that is continuous with the first insertion portion 710a and has a relatively smaller outer diameter, and an insertion hole 710c that penetrates the first insertion portion 710a and the second insertion portion 710b. As shown in Figure 5, the positive electrode side first gasket 710 is provided between the positive electrode terminal 410 and the positive electrode current collector plate 210. The first insertion portion 710a is inserted into the insertion hole 620b of the positive electrode side insulating plate 620 shown in Figure 12. The second insertion portion 710b is inserted into the positive electrode side insertion hole 520a of the lid 520 shown in Figure 12 and the insertion hole 720b of the positive electrode side second gasket 720. The insertion portion 410b of the positive electrode terminal 410 shown in Figure 12 is inserted into the insertion hole 710c. The positive electrode side first gasket 710 is formed of, for example, rubber that has insulating and elastic properties.

[0041] The positive electrode side second gasket 720 seals the positive electrode terminal 410 and the cover 520. As shown in Figure 12, the positive electrode side second gasket 720 includes a rectangular plate-shaped base portion 720a, an insertion hole 720b that penetrates the base portion 720a, and a protrusion 720c that surrounds the side edge of the base portion 720a in an annular shape and protrudes away from the cover 520. The positive electrode terminal 410 is housed in the space formed by the base portion 720a and the protrusion 720c of the positive electrode side second gasket 720. The insertion portion 410b of the positive electrode terminal 410 is inserted into the insertion hole 720b. The positive electrode side second gasket 720 is formed of, for example, an insulating resin.

[0042] The first gasket 730 on the negative electrode side seals the negative electrode current collector plate 220 and the lid 520, and seals the exterior body 500. The first gasket 730 on the negative electrode side is formed in a cylindrical shape. As shown in FIG. 10, the first gasket 730 on the negative electrode side includes a first insertion portion 730a having a relatively large outer diameter, a second insertion portion 730b that is continuous with the first insertion portion 730a and has a relatively small outer diameter, and an insertion hole 730c that penetrates the first insertion portion 730a and the second insertion portion 730b. As shown in FIG. 3, the first gasket 730 on the negative electrode side is provided between the second member 422 of the negative electrode terminal 420 and the negative electrode current collector plate 220. The first insertion portion 730a is inserted into the insertion hole 630b of the negative electrode side insulating plate 630 shown in FIG. 10. The second insertion portion 730b is inserted into the negative electrode side insertion hole 520b of the lid 520 and the insertion hole 740b of the second gasket 740 on the negative electrode side shown in FIG. 10. The main body portion 421b of the first member 421 of the negative electrode terminal 420 shown in FIG. 10 is inserted into the insertion hole 730c. The first gasket 730 on the negative electrode side is formed of, for example, rubber having insulation and elasticity.

[0043] The second gasket 740 on the negative electrode side seals the negative electrode terminal 420 and the lid 520. As shown in FIG. 10, the second gasket 740 on the negative electrode side includes a rectangular plate-shaped base portion 740a, an insertion hole 740b that penetrates the base portion 740a, and a convex portion 740c that annularly surrounds the side edge of the base portion 740a and protrudes in a direction away from the lid 520. The negative electrode terminal 420 is accommodated in a space formed by the base portion 740a and the convex portion 740c in the second gasket 740 on the negative electrode side. The insertion portion 420b of the negative electrode terminal 420 is inserted into the insertion hole 740b. The second gasket 740 on the negative electrode side is formed of, for example, insulating resin.

[0044] Referring to FIGS. 6, 7, and 13 to 15, the configuration of the tabs (the positive electrode tab 111b and the negative electrode tab 121b) and the joint portion between the tabs and the current collector 200 will be described. As shown in FIGS. 6 and 7, a plurality of positive electrode tabs 111b and a plurality of negative electrode tabs 121b protrude from one end surface of the wound portion of the charge and discharge body 100 to one side in the height direction Z of the battery 1. Hereinafter, the height direction Z, the longitudinal direction X, and the lateral direction Y of the battery 1 are also referred to as the height direction Z, the longitudinal direction X, and the lateral direction Y of the charge and discharge body 100.

[0045] The structure of the positive electrode tab 111b is the same as that of the negative electrode tab 121b. Also, the joining structure between the positive electrode tab 111b and the positive electrode current collector plate 210 is the same as the joining structure between the negative electrode tab 121b and the negative electrode current collector plate 220. Therefore, the structure of the negative electrode tab 121b and the joining structure between the negative electrode tab 121b and the negative electrode current collector plate 220 will be described as a representative, and the description of the structure of the positive electrode tab 111b and the joining structure between the positive electrode tab 111b and the positive electrode current collector plate 210 will be omitted.

[0046] FIG. 13 is a perspective view of the charge and discharge body 100 in a state where misalignment of a plurality of negative electrode tabs 121b does not occur, and FIG. 14 is a perspective view of the charge and discharge body 100 in a state where misalignment of a plurality of negative electrode tabs 121b occurs. The width of the charge and discharge body 100 in the longitudinal direction X of the negative electrode tab 121b, that is, the width along the winding direction of the charge and discharge body 100, will be hereinafter referred to as the lateral width. As shown in FIGS. 13 and 14, the plurality of negative electrode tabs 121b include a plurality of negative electrode tabs 121b having different lateral widths from each other. The plurality of negative electrode tabs 121b are arranged such that the lateral width gradually increases from the outside to the inside of the charge and discharge body 100. That is, the plurality of negative electrode tabs 121b include, on the inside of the charge and discharge body 100, a negative electrode tab 121b having a wider lateral width than the outer negative electrode tabs 121b. Here, the inside of the charge and discharge body 100 corresponds to the side of the winding central axis of the charge and discharge body 100. The outside of the charge and discharge body 100 corresponds to the side of the outer peripheral surface of the charge and discharge body 100.

[0047] The plurality of negative electrode tabs 121b have the first negative electrode tab 121b1 to the twelfth negative electrode tab 121b12. The first negative electrode tab 121b1 is arranged at the innermost side of the charge and discharge body 100 among the plurality of negative electrode tabs 121b. That is, the first negative electrode tab 121b1 is the negative electrode tab 121b closest to the start end of the winding of the sheet structure. The twelfth negative electrode tab 121b12 is arranged at the outermost side of the charge and discharge body 100 among the plurality of negative electrode tabs 121b. That is, the twelfth negative electrode tab 121b12 is the negative electrode tab 121b closest to the end of the winding of the sheet structure.

[0048] With respect to the central plane Cp that divides the charge / discharge body 100 into two equal parts in the short direction Y, the first negative electrode tab 121b1, the third negative electrode tab 121b3, the fifth negative electrode tab 121b5, the seventh negative electrode tab 121b7, the ninth negative electrode tab 121b9, and the eleventh negative electrode tab 121b11 are arranged on one side. With respect to the central plane Cp of the charge / discharge body 100, the second negative electrode tab 121b2, the fourth negative electrode tab 121b4, the sixth negative electrode tab 121b6, the eighth negative electrode tab 121b8, the tenth negative electrode tab 121b10, and the twelfth negative electrode tab 121b12 are arranged on the other side.

[0049] The first negative electrode tab 121b1, the third negative electrode tab 121b3, the fifth negative electrode tab 121b5, the seventh negative electrode tab 121b7, the ninth negative electrode tab 121b9, and the eleventh negative electrode tab 121b11 are arranged in this order from the inside to the outside of the charge / discharge body 100. The second negative electrode tab 121b2, the fourth negative electrode tab 121b4, the sixth negative electrode tab 121b6, the eighth negative electrode tab 121b8, the tenth negative electrode tab 121b10, and the twelfth negative electrode tab 121b12 are arranged in this order from the inside to the outside of the charge / discharge body 100.

[0050] Figure 15 is a perspective view showing the joint between the multiple negative electrode tabs 121b and the negative electrode current collector plate 220. In Figure 15, only three of the multiple negative electrode tabs 121b are shown as representative. As shown in Figure 15, the multiple negative electrode tabs 121b are bundled together and joined to the negative electrode current collector plate 220 in a curved state. The multiple negative electrode tabs 121b are joined to the negative electrode current collector plate 220, for example, by laser beam welding. It is preferable that the protruding length of the multiple negative electrode tabs 121b is set so that the positions of the tips of the multiple negative electrode tabs 121b are aligned when the multiple negative electrode tabs 121b are joined to the negative electrode current collector plate 220.

[0051] The effects and advantages of this embodiment will be explained in detail with reference to Figures 16A and 16B. Figure 16A is a schematic plan view of the charge / discharge body 100 in a state where there is no misalignment of the multiple negative electrode tabs 121b, and shows the arrangement of the multiple negative electrode tabs 121b. As shown in Figure 16A, the multiple negative electrode tabs 121b are formed so that the width of each tab increases from the outside to the inside of the charge / discharge body 100.

[0052] Specifically, the width Be1 of the first negative electrode tab 121b1 and the second negative electrode tab 121b2 is wider than the width Be2 of the third negative electrode tab 121b3 and the fourth negative electrode tab 121b4 (Be1 > Be2). The width Be2 of the third negative electrode tab 121b3 and the fourth negative electrode tab 121b4 is wider than the width Be3 of the fifth negative electrode tab 121b5 and the sixth negative electrode tab 121b6 (Be2 > Be3). The width Be3 of the fifth negative electrode tab 121b5 and the sixth negative electrode tab 121b6 is wider than the width Be4 of the seventh negative electrode tab 121b7 and the eighth negative electrode tab 121b8 (Be3 > Be4). The width Be4 of the 7th negative electrode tab 121b7 and the 8th negative electrode tab 121b8 is wider than the width Be5 of the 9th negative electrode tab 121b9 and the 10th negative electrode tab 121b10 (Be4 > Be5). The width Be5 of the 9th negative electrode tab 121b9 and the 10th negative electrode tab 121b10 is wider than the width Be6 of the 11th negative electrode tab 121b11 and the 12th negative electrode tab 121b12 (Be5 > Be6).

[0053] In this manner, the multiple negative electrode tabs 121b are arranged so that their widths continuously increase one by one from the outside to the inside of the charge / discharge body 100. Note that the width of the first negative electrode tab 121b1 and the width of the second negative electrode tab 121b2 do not have to be the same. In this case, it is preferable that the width of the second negative electrode tab 121b2 be wider than the width of the first negative electrode tab 121b1 and narrower than the width of the third negative electrode tab 121b3. Similarly, the width of the third negative electrode tab 121b3 and the width of the fourth negative electrode tab 121b4 do not have to be the same. In this case, it is preferable that the width of the fourth negative electrode tab 121b4 be wider than the width of the third negative electrode tab 121b3 and narrower than the width of the fifth negative electrode tab 121b5. Similarly, the width of the fifth negative electrode tab 121b5 and the width of the sixth negative electrode tab 121b6 do not have to be the same. In this case, it is preferable that the width of the sixth negative electrode tab 121b6 be wider than the width of the fifth negative electrode tab 121b5 and narrower than the width of the seventh negative electrode tab 121b7. Similarly, the widths of the seventh negative electrode tab 121b7 and the eighth negative electrode tab 121b8 do not have to be the same. In this case, it is preferable that the width of the eighth negative electrode tab 121b8 be wider than the width of the seventh negative electrode tab 121b7 and narrower than the width of the ninth negative electrode tab 121b9. Similarly, the widths of the ninth negative electrode tab 121b9 and the tenth negative electrode tab 121b10 do not have to be the same. In this case, it is preferable that the width of the tenth negative electrode tab 121b10 be wider than the width of the ninth negative electrode tab 121b9 and narrower than the width of the eleventh negative electrode tab 121b11. Similarly, the width of the 11th negative electrode tab 121b11 and the width of the 12th negative electrode tab 121b12 do not have to be the same. In this case, it is preferable that the width of the 12th negative electrode tab 121b12 be wider than the width of the 11th negative electrode tab 121b11.

[0054] Furthermore, the multiple negative electrode tabs 121b may be arranged so that their width gradually increases in units of multiple tabs from the outside to the inside of the charge / discharge body 100. For example, widths Be1 and Be2 may be the same, widths Be3 and Be4 may be the same, and widths Be5 and Be6 may be the same (Be1=Be2>Be3=Be4>Be5=Be6).

[0055] The charge / discharge body 100 is manufactured by a winding process in which a single, elongated sheet structure is formed by stacking a separator 130, a negative electrode 120, another separator 130, and a positive electrode 110 in that order, and then winding it (see Figure 7). The charge / discharge body 100 has a flattened shape and has a pair of curved portions 100c that are arc-shaped in plan view and formed at both ends in the longitudinal direction X, and a flat portion 100p connected to the pair of curved portions 100c. Multiple negative electrode tabs 121b protrude from the flat portion 100p. In other words, the width of the negative electrode tabs 121b corresponds to the width dimension in the direction perpendicular to the stacking direction of the positive electrode 110, negative electrode 120, and separator 130 in the flat portion 100p (i.e., the short direction Y) and the protruding direction of the negative electrode tabs 121b (i.e., the height direction Z) (i.e., the longitudinal direction X).

[0056] During the winding process, tension is applied to the positive electrode 110, the negative electrode 120, and the separator 130. Due to the tension, elongation occurs in the positive electrode 110 and the negative electrode 120, which may cause misalignment (winding misalignment) in multiple positive electrode tabs 111b and multiple negative electrode tabs 121b. The amount of misalignment of the positive electrode tabs 111b and negative electrode tabs 121b from their target positions (design positions) accumulates with each winding. Therefore, the further out the tabs are positioned on the outside of the charge / discharge body 100, the greater the amount of misalignment from the target position.

[0057] Figure 16B is a schematic plan view of the charge / discharge unit 100 in a state where there is misalignment of multiple negative electrode tabs 121b. In the example shown in Figure 16B, the tab located furthest out of the multiple negative electrode tabs 121b is the 12th negative electrode tab 121b12. Therefore, the misalignment amount Dx of the 12th negative electrode tab 121b12 from its target position is larger than the misalignment amounts of the other negative electrode tabs 121b. In other words, the misalignment amount Dx shown corresponds to the maximum misalignment amount among the multiple negative electrode tabs 121b.

[0058] In this embodiment, as described above, the multiple negative electrode tabs 121b are arranged such that their width gradually increases from the outside to the inside of the charge / discharge body 100. The target positions of the negative electrode tabs 121b are set on the same straight line perpendicular to the center plane Cp (see Figure 16A). Furthermore, the width of each negative electrode tab 121b is set so that the necessary contact area (target area) with respect to the negative electrode current collector plate 220 can be secured even if the expected positional misalignment occurs. Therefore, if positional misalignment occurs in the multiple negative electrode tabs 121b, when the multiple negative electrode tabs 121b are viewed from the short side direction Y, a sufficient area of ​​the region where all the negative electrode tabs 121b overlap (overlapping region) can be secured. In other words, the width Beo of the overlapping region can be set to a value greater than or equal to the design value (target value). As a result, a sufficient contact area between the bundled multiple negative electrode tabs 121b and the negative electrode current collector plate 220 can be secured.

[0059] In contrast, if misalignment occurs in a configuration where all of the multiple negative electrode tabs 121b have the same width, there is a risk that a sufficient bonding area cannot be secured. Figure 17A is a schematic plan view of the charge / discharge body 1000 according to a comparative example of this embodiment in a state where no misalignment of the multiple negative electrode tabs 1021b has occurred, and Figure 17B is a schematic plan view of the charge / discharge body 1000 according to a comparative example of this embodiment in a state where misalignment of the multiple negative electrode tabs 1021b has occurred.

[0060] As shown in Figures 17A and 17B, in the comparative example of this embodiment, the width Bc of all the negative electrode tabs 1021b are equal. In this configuration, if the misalignment of the multiple negative electrode tabs 1021b is large, there is a risk that the area of ​​the region where all the negative electrode tabs 121b overlap (overlapping region) cannot be sufficiently secured when the multiple negative electrode tabs 1021b are viewed from the short side direction Y. In other words, there is a risk that the width Bco of the overlapping region cannot be sufficiently secured. As a result, there is a risk that the bonding area between the bundled multiple negative electrode tabs 1021b and the negative electrode current collector plate 220 cannot be sufficiently secured.

[0061] In the comparative example, to ensure sufficient overlapping area, it is conceivable to widen the width Bc. However, if the width Bc is widened, the overall width Bcx of the bundled negative electrode tabs 1021b will increase in the event of misalignment, which may make it difficult to join them to the limited space of the negative electrode current collector plate 220.

[0062] In contrast, in this embodiment, as shown in Figures 16A and 16B, the multiple negative electrode tabs 121b are arranged such that their width gradually increases from the outside to the inside of the charge / discharge body 100. Therefore, even if misalignment of the negative electrode tabs 121b occurs, the overall width Bex of the bundled multiple negative electrode tabs 121b is suppressed to increase. As a result, according to this embodiment, the connection between the multiple negative electrode tabs 121b and the negative electrode current collector plate 220 can be easily performed, and a sufficient connection area between the multiple negative electrode tabs 121b and the negative electrode current collector plate 220 can be secured.

[0063] As shown in Figure 16B, the width of the negative electrode tab 121b is set considering the case where a positional displacement occurs at the maximum positional displacement amount Dx. As shown in the figure, even when a positional displacement occurs at the maximum positional displacement amount Dx, it is preferable that the following conditions are satisfied. (Condition 1) In the multiple negative electrode tabs 121b arranged on one side (the lower side in the figure) with respect to the central plane Cp, the third negative electrode tab 121b3 to the eleventh negative electrode tab 121b11 do not protrude outside the longitudinal direction X beyond both ends of the width direction of the first negative electrode tab 121b1. That is, when viewed from the short direction Y, the projected areas of the third negative electrode tab 121b3 to the eleventh negative electrode tab 121b11 are contained within the projected area of ​​the first negative electrode tab 121b1. (Condition 2) In the multiple negative electrode tabs 121b arranged on the other side (upper side in the figure) with respect to the central plane Cp, the fourth negative electrode tab 121b4 to the twelfth negative electrode tab 121b12 do not extend beyond the ends of the second negative electrode tab 121b2 in the width direction in the longitudinal direction X. That is, when viewed from the short direction Y, the projected areas of the fourth negative electrode tab 121b4 to the twelfth negative electrode tab 121b12 are contained within the projected area of ​​the second negative electrode tab 121b2.

[0064] In this way, the multiple negative electrode tabs 121b are arranged such that, when the charge / discharge body 100 is viewed from the short side Y, the width of the tabs located outside the charge / discharge body 100 (e.g., the third negative electrode tab 121b3, fifth negative electrode tab 121b5, seventh negative electrode tab 121b7, ninth negative electrode tab 121b9, eleventh negative electrode tab 121b11) fits within the width of the tab located inside the charge / discharge body 100 (e.g., the first negative electrode tab 121b1) (see Figures 13, 14, etc.). With this configuration, the overlapping area of ​​the negative electrode tabs 121b can be made wider. Therefore, the overall width Bex of the bundled multiple negative electrode tabs 121b can be suppressed while ensuring a sufficient contact area between the negative electrode tabs 121b and the negative electrode current collector plate 220.

[0065] The configuration of the multiple negative electrode tabs 121b has been described with reference to Figures 13 to 16B, and the configuration of the multiple positive electrode tabs 111b is similar.

[0066] (Effects of Battery 1 in the First Embodiment) The effects of Battery 1 in the first embodiment will be described below.

[0067] In this embodiment, the multiple negative electrode tabs 121b are arranged such that their width (horizontal width) gradually increases from the outside to the inside of the charge / discharge body 100, along the winding direction of the charge / discharge body 100. With this configuration, even if misalignment occurs in the multiple negative electrode tabs 121b due to manufacturing errors such as winding misalignment, a sufficient contact area between the multiple negative electrode tabs 121b and the negative electrode current collector plate 220 can be secured. As a result, electrical resistance on the negative electrode side is reduced, and conductivity is improved. Similarly, the multiple positive electrode tabs 111b are arranged such that their width (horizontal width) gradually increases from the outside to the inside of the charge / discharge body 100, along the winding direction of the charge / discharge body 100. With this configuration, even if misalignment occurs in the multiple positive electrode tabs 111b due to manufacturing errors such as winding misalignment, a sufficient contact area between the multiple positive electrode tabs 111b and the positive electrode current collector plate 210 can be secured. As a result, electrical resistance on the positive electrode side is reduced, and conductivity is improved.

[0068] The charge / discharge body 100 tends to accumulate heat towards the inside (towards the winding center axis). In this embodiment, the width of each of the multiple negative electrode tabs 121b and multiple positive electrode tabs 111b is wider towards the inside of the charge / discharge body 100. Therefore, the heat from the charge / discharge body 100 can be effectively released.

[0069] (Configuration of Battery 1 in the Second Embodiment) Battery 1 in the second embodiment has a charge / discharge unit 800 as shown in Figure 18.

[0070] (Configuration of the charge / discharge unit 800) The configuration of the charge / discharge unit 800 will be described with reference to Figure 18. Figure 18 is a perspective view of the charge / discharge unit 800 according to the second embodiment, in a state in which no misalignment of the multiple negative electrode tabs 821b has occurred.

[0071] In the second embodiment, components identical to those in the first embodiment are given the same reference numerals as in the first embodiment and their descriptions are omitted. In the second embodiment, components different from those in the first embodiment are given different reference numerals and described accordingly. In the second embodiment, the configuration of the multiple negative electrode tabs 821b differs from the configuration of the multiple negative electrode tabs 121b in the first embodiment.

[0072] In the first embodiment, as shown in Figure 13, a plurality of negative electrode tabs 121b were arranged such that their width gradually increased from the outside to the inside of the charge / discharge body 100.

[0073] In contrast, in the second embodiment, as shown in Figure 18, a plurality of negative electrode tabs 821b are arranged such that their width gradually increases from the inside to the outside of the charge / discharge body 800.

[0074] The multiple negative electrode tabs 821b include a first negative electrode tab 821b1 to a twelfth negative electrode tab 821b12. The first negative electrode tab 821b1 is located on the innermost side of the charge / discharge body 800 among the multiple negative electrode tabs 821b. In other words, the first negative electrode tab 821b1 is the negative electrode tab 821b closest to the winding start end of the sheet structure. The twelfth negative electrode tab 821b12 is located on the outermost side of the charge / discharge body 800 among the multiple negative electrode tabs 821b. In other words, the twelfth negative electrode tab 821b12 is the negative electrode tab 821b closest to the winding end of the sheet structure.

[0075] With respect to the central plane Cp of the charge / discharge body 800, the first negative electrode tab 821b1, the third negative electrode tab 821b3, the fifth negative electrode tab 821b5, the seventh negative electrode tab 821b7, the ninth negative electrode tab 821b9, and the eleventh negative electrode tab 821b11 are arranged on one side. With respect to the central plane Cp of the charge / discharge body 800, the second negative electrode tab 821b2, the fourth negative electrode tab 821b4, the sixth negative electrode tab 821b6, the eighth negative electrode tab 821b8, the tenth negative electrode tab 821b10, and the twelfth negative electrode tab 821b12 are arranged on the other side.

[0076] The first negative electrode tab 821b1, the third negative electrode tab 821b3, the fifth negative electrode tab 821b5, the seventh negative electrode tab 821b7, the ninth negative electrode tab 821b9, and the eleventh negative electrode tab 821b11 are arranged in this order from the inside to the outside of the charge / discharge body 800. The second negative electrode tab 821b2, the fourth negative electrode tab 821b4, the sixth negative electrode tab 821b6, the eighth negative electrode tab 821b8, the tenth negative electrode tab 821b10, and the twelfth negative electrode tab 821b12 are arranged in this order from the inside to the outside of the charge / discharge body 800.

[0077] In this second embodiment, the multiple negative electrode tabs 821b are formed such that their width increases one by one from the inside to the outside of the charge / discharge body 800.

[0078] Specifically, the widths of the first negative electrode tab 821b1 and the second negative electrode tab 821b2 are narrower than the widths of the third negative electrode tab 821b3 and the fourth negative electrode tab 821b4. The widths of the third negative electrode tab 821b3 and the fourth negative electrode tab 821b4 are narrower than the widths of the fifth negative electrode tab 821b5 and the sixth negative electrode tab 821b6. The widths of the fifth negative electrode tab 821b5 and the sixth negative electrode tab 821b6 are narrower than the widths of the seventh negative electrode tab 821b7 and the eighth negative electrode tab 821b8. The widths of the seventh negative electrode tab 821b7 and the eighth negative electrode tab 821b8 are narrower than the widths of the ninth negative electrode tab 821b9 and the tenth negative electrode tab 821b10. The width of the ninth negative electrode tab 821b9 and the tenth negative electrode tab 821b10 is narrower than the width of the eleventh negative electrode tab 821b11 and the twelfth negative electrode tab 821b12.

[0079] (Effects of Battery 1 in the Second Embodiment) The effects of Battery 1 in the second embodiment will be described with reference to Figure 19. Figure 19 is a perspective view of the charge / discharge body 800 according to the second embodiment, in which a misalignment of the multiple negative electrode tabs 821b has occurred.

[0080] In this second embodiment, the multiple negative electrode tabs 821b are arranged such that their width (horizontal width) gradually increases from the inside to the outside of the charge / discharge body 800, along the winding direction of the charge / discharge body 800. Furthermore, when the charge / discharge body 100 is viewed from the short side Y, the multiple negative electrode tabs 821b are arranged such that the width of the tabs located inside the charge / discharge body 800 (for example, the 11th negative electrode tab 821b11) is contained within the width of the tab located outside the charge / discharge body 800 (for example, the 11th negative electrode tab 821b11).

[0081] With this configuration, as shown in Figure 19, if misalignment occurs between the multiple negative electrode tabs 821b, similar to the first embodiment, a sufficient area of ​​the region where all the negative electrode tabs 821b overlap (overlapping region) can be secured when the multiple negative electrode tabs 821b are viewed from the short-side direction Y of the charge / discharge body 800. As a result, a sufficient contact area between the bundled multiple negative electrode tabs 821b and the negative electrode current collector plate 220 can be secured.

[0082] (Configuration of the battery 1 in the third embodiment) The battery 1 in the second embodiment has a charge / discharge unit 900 as shown in Figure 20.

[0083] (Configuration of the charge / discharge unit 900) The configuration of the charge / discharge unit 900 will be described with reference to Figure 20. Figure 20 is a perspective view of the charge / discharge unit 900 according to the third embodiment, in a state in which no misalignment of the multiple negative electrode tabs 121b has occurred.

[0084] In the third embodiment, components identical to those in the first embodiment are given the same reference numerals as in the first embodiment and their descriptions are omitted. In the third embodiment, components different from those in the first embodiment are given different reference numerals and described accordingly. In the third embodiment, the method for manufacturing the charge / discharge body 900 differs from the method for manufacturing the charge / discharge body 100 in the first embodiment.

[0085] In the first embodiment, the charge / discharge body 100 was manufactured by winding a single sheet structure in which a separator 130, a negative electrode 120, a separator 130, and a positive electrode 110 were stacked in that order. In contrast, in the third embodiment, the charge / discharge body 900 is manufactured by stacking multiple rectangular sheet structures that are shorter than the length X in the longitudinal direction of the container 510. This sheet structure is a structure in which a rectangular separator, a rectangular negative electrode, a rectangular separator, and a rectangular positive electrode are stacked in that order. For this reason, the charge / discharge body 900 according to this third embodiment does not have the curved portion 100c described in the first embodiment, and only has a flat portion 900p in the shape of a flattened rectangular parallelepiped.

[0086] The manufacturing method for the charge / discharge body 900 according to the third embodiment does not include the winding process described in the first embodiment. Therefore, no elongation of the sheet structure occurs due to the tension acting on the sheet structure when the winding process is performed. However, the third embodiment includes a process of stacking multiple sheet structures. Therefore, when stacking multiple sheet structures, there is a risk of misalignment of the negative electrode tab 121b. Furthermore, when forming the negative electrode tab 121b by laser processing on an exposed portion at one end of the negative electrode current collector layer 121 where the negative electrode active material layer 122 is not provided, there is a risk of misalignment of the negative electrode tab 121b due to processing errors. In addition, during the pressing process in the process of joining the negative electrode current collector (negative electrode current collector foil) 121a to the negative electrode current collector, there is a risk of misalignment of the negative electrode tab 121b due to elongation of the negative electrode current collector 121a.

[0087] (Effects of the Battery 1 of the Third Embodiment) The effects of the Battery 1 of the third embodiment will be described with reference to Figure 21. Figure 21 is a perspective view of the charge / discharge body 900 according to the third embodiment, in which a misalignment of the multiple negative electrode tabs 121b has occurred.

[0088] In this third embodiment, the multiple negative electrode tabs 121b are formed such that their width gradually increases from the outside to the inside of the charge / discharge body 900. With this configuration, as shown in Figure 21, if misalignment occurs between the multiple negative electrode tabs 121b, as in the first embodiment, a sufficient area of ​​the region where all the negative electrode tabs 121b overlap (overlapping region) can be secured when the multiple negative electrode tabs 121b are viewed from the short side direction Y. As a result, a sufficient contact area between the bundled multiple negative electrode tabs 121b and the negative electrode current collector plate 220 can be secured.

[0089] (Batteries of other embodiments) The battery of the present invention is not limited to the configuration of the battery described in the embodiments, but can be configured as appropriate based on the contents described in the claims.

[0090] The embodiments are described in detail or in a simplified manner to clearly illustrate the present invention, and it is not necessary to have all the configurations described, or to have configurations that are not shown. Furthermore, some of the configurations of the embodiments may be deleted, replaced with configurations from other embodiments, or combined with configurations from other embodiments.

[0091] In the above embodiment, an example was described in which the positive electrode tab 111b is joined to the positive electrode current collector plate 210, and the positive electrode tab 111b is electrically connected to the positive electrode terminal 410 via the positive electrode current collector plate 210, and the negative electrode tab 121b is joined to the negative electrode current collector plate 220, and the negative electrode tab 121b is electrically connected to the negative electrode terminal 420 via the negative electrode current collector plate 220. However, the bundled positive electrode tabs 111b may be directly joined to the positive electrode terminal 410, which is a positive electrode conductive member. Similarly, the bundled negative electrode tabs 121b may be directly joined to the negative electrode terminal 420, which is a negative electrode conductive member.

[0092] In the above embodiment, an example was described in which both the plurality of positive electrode tabs 111b and the plurality of negative electrode tabs 121b are arranged such that their width gradually increases from one side of the charge / discharge body 100, 800, 900 to the other side. However, only the plurality of positive electrode tabs 111b may be arranged such that their width gradually increases from one side of the charge / discharge body 100, 800, 900 to the other side. Alternatively, only the plurality of negative electrode tabs 121b may be arranged such that their width gradually increases from one side of the charge / discharge body 100, 800, 900 to the other side.

[0093] In the first and second embodiments, examples of applying the present invention to a battery in which a positive electrode tab and a negative electrode tab protrude from one end of a flat-shaped charge / discharge body 100, 800 in the winding axis direction were described. However, the present invention may also be applied to a battery in which a positive electrode tab protrudes from one end of a cylindrical charge / discharge body housed in a cylindrical container, and a negative electrode tab protrudes from the other end in the axial direction.

[0094] The battery of the present invention is not limited to lithium-ion batteries. For example, the battery of the present invention can be applied to nickel-metal hydride batteries and lead-acid batteries. The battery of the present invention is not limited to secondary batteries. The battery of the present invention can be applied to primary batteries.

[0095] The battery charge / discharge element of the present invention can be of a laminated type in which a plurality of relatively short positive electrodes and a plurality of negative electrodes are alternately arranged on a single elongated separator, facing each other via the separator. In such a configuration, the positive and negative electrodes face each other via the separator by folding and laminating the separator. The battery of the present invention is not limited to a configuration with one charge / discharge element. The battery of the present invention can be applied to a configuration with two or more charge / discharge elements. The battery of the present invention is not limited to a configuration in which the charge / discharge element is sealed by a container and a lid. The battery of the present invention can be applied to a configuration in which the charge / discharge element is sealed by a laminate film.

[0096] The configuration, operation, and effects of the embodiment of the present invention configured as described above will be summarized below.

[0097] (1) The battery 1 comprises charge / discharge elements 100, 800, and 900, a positive electrode conductive member (positive electrode current collector plate 210, positive electrode terminal 410), and a negative electrode conductive member (negative electrode current collector plate 220, negative electrode terminal 420). The charge / discharge elements 100, 800, and 900 are stacked, each comprising a positive electrode 110, a negative electrode 120, and a separator (insulating member) 130 provided between the positive electrode 110 and the negative electrode 120. The separator 130 is an insulating member having insulating properties. The positive electrode 110 has a positive electrode current collector 111a and a plurality of positive electrode tabs 111b which are a plurality of tabs protruding from the positive electrode current collector 111a. The negative electrode 120 has a negative electrode current collector 121a and a plurality of negative electrode tabs 121b which are a plurality of tabs protruding from the negative electrode current collector 121a. Multiple positive electrode tabs 111b are bonded together to a positive electrode conductive member (e.g., a positive electrode current collector plate 210). Multiple negative electrode tabs 121b are bonded together to a negative electrode conductive member (e.g., a negative electrode current collector plate 220). At least one of the multiple positive electrode tabs 111b and the multiple negative electrode tabs 121b includes a tab that is wider on one side of the charge / discharge body 100, 800, 900, both on the outside and inside, than the tab on the other side.

[0098] This configuration makes it possible to obtain a battery 1 in which the tab and conductive members such as the current collector 200 and electrode terminals 400 are sufficiently joined.

[0099] (2) The charge / discharge bodies 100, 800 are wound bodies in which at least the positive electrode 110 and the negative electrode 120 are wound around a separator 130 (see Figure 7, etc.).

[0100] With this configuration, even if misalignment of the tabs occurs in the winding process for manufacturing the charge / discharge bodies 100, 800 due to stretching of the positive electrode 110 and negative electrode 120 caused by the tension acting on them, a sufficient contact area between the multiple tabs and the conductive member can be secured.

[0101] (3) At least one of the multiple positive electrode tabs 111b and the multiple negative electrode tabs 121b is arranged such that the width of the charge / discharge body 100 gradually increases from the outside to the inside of the charge / discharge body 100 along the winding direction of the charge / discharge body 100 (see Figures 13, 14, etc.).

[0102] With this configuration, the wide tab is placed on the inside of the charge / discharge body 100, which is more prone to heat accumulation than the outside of the charge / discharge body 100, thus enabling effective heat dissipation from the charge / discharge body 100.

[0103] (4) At least one of the multiple positive electrode tabs 111b and the multiple negative electrode tabs 121b is arranged such that its width gradually increases from the inside to the outside of the charge / discharge body 800 along the winding direction of the charge / discharge body 800 (see Figures 18 and 19).

[0104] In this configuration, wider tabs are positioned on the outside of the charge / discharge body 800, where the amount of tab displacement is greater. Therefore, even when the amount of displacement becomes larger, sufficient contact area between the multiple tabs and the conductive member can be secured.

[0105] (5) The positive electrode current collector 111a and the positive electrode tab 111b contain aluminum. The negative electrode current collector 121a and the negative electrode tab 121b contain copper. The plurality of positive electrode tabs 111b are arranged such that their width gradually increases along the winding direction of the charge / discharge bodies 100, 800, from one side to the other, on the outside and inside of the charge / discharge bodies 100, 800.

[0106] The positive electrode current collector 111a is more prone to stretching than the negative electrode current collector 121a, and is more susceptible to tab misalignment. Therefore, by adjusting the width of the tab on the positive electrode side and ensuring sufficient contact area between the positive electrode tab and the conductive material, a more reliable battery 1 can be provided.

[0107] Furthermore, by widening the width of the positive electrode tab 111b, which has a lower thermal conductivity than the negative electrode tab 121b, the heat dissipation effect on the positive electrode side can be improved. For example, by keeping the tab width constant on the negative electrode side and widening the tab width on the positive electrode side, the heat dissipation can be made equal on both the positive and negative electrode sides. As a result, the temperature gradient within the charge / discharge body can be reduced.

[0108] (6) At least one of the multiple positive electrode tabs 111b and the multiple negative electrode tabs 121b is arranged such that the width of the charge / discharge body 100 gradually widens from the outside to the inside of the charge / discharge body 100 along the winding direction of the charge / discharge body 100, and the width of the tabs located outside the charge / discharge body 100 (e.g., the third negative electrode tab 121b3, the fifth negative electrode tab 121b5, the seventh negative electrode tab 121b7, the ninth negative electrode tab 121b9, the eleventh negative electrode tab 121b11) fits within the width range of the tab located inside the charge / discharge body 100 (e.g., the first negative electrode tab 121b1) (see Figures 13, 14, etc.).

[0109] With this configuration, in a battery 1 in which the width of the tabs increases continuously or intermittently from the outside to the inside of the charge / discharge body 100, a more sufficient contact area between the multiple tabs and the conductive member can be secured.

[0110] (7) At least one of the plurality of positive electrode tabs 111b and the plurality of negative electrode tabs 121b is arranged such that the width of the charge / discharge body 800 gradually widens from the inside to the outside of the charge / discharge body 800 along the winding direction of the charge / discharge body 800, and the width of the tabs that are located inside the charge / discharge body 800 (first negative electrode tab 821b1, third negative electrode tab 821b3, fifth negative electrode tab 821b5, seventh negative electrode tab 821b7, ninth negative electrode tab 821b9) is within the width range of the tab located outside the charge / discharge body 800 (e.g., the 11th negative electrode tab 821b11) (see Figures 18 and 19).

[0111] With this configuration, in a battery 1 in which the width of the tabs increases continuously or intermittently from the inside to the outside of the charge / discharge body 100, a more sufficient contact area between the multiple tabs and the conductive member can be secured.

[0112] 1...Battery, 100...Charging / discharging element, 100a...One side, 100c...Curved part, 100p...Flat part, 110...Positive electrode, 111...Positive electrode current collector layer, 111a...Positive electrode current collector (positive electrode current collector foil), 111b...Positive electrode tab (tab), 111c...Side edge, 112...Positive electrode active material layer, 120...Negative electrode, 121...Negative electrode current collector layer, 121a...Negative electrode current collector (negative electrode current collector foil), 121b...Negative electrode tab (tab), 121c...Side edge, 122...Negative electrode active material layer, 130...Separator (insulating material), 140...Electrolyte, 200...Current collector (conductive material), 210...Positive electrode current collector plate (positive electrode conductive material), 210a...First base, 210b...First 2...base, 210c...connecting part, 210d...recess, 210e...weak part, 220...negative electrode current collector plate (negative electrode conductive member), 220a...base, 220b...insertion hole, 300...current interrupter, 310...diaphragm, 310a...main body, 310b...first joint, 310c...second joint, 320...conducting member, 320a...base, 320b...insertion hole, 330...support base, 330a...main body, 330b...leg, 340...plug, 400...electrode terminal (conductive member), 410...positive electrode terminal (positive electrode conductive member), 410a...base, 410b...insertion part, 410c...joint, 410d...through part, 420...negative electrode terminal (Negative electrode conductive member), 420a...base, 420b...insertion part, 420c...joint part, 421...first member, 421b...main body, 422...second member, 500...outer body, 510...container, 510a...opening, 510b...housing part, 520...lid, 520a...positive electrode side insertion hole, 520b...negative electrode side insertion hole, 520c...insertion hole for liquid injection, 530...opening valve, 540...sealing plug, 540a...head, 540b...insertion part, 600...insulator, 610...insulating cover, 620...positive electrode side insulating plate, 620a...base, 620b...insertion hole, 620c...protrusion, 630...negative electrode side insulating plate, 630a...base, 630b...insertion Hole, 630c... protrusion, 700... sealing body, 710... positive electrode side first gasket, 710a... first insertion part, 710b... second insertion part, 710c... insertion hole, 720... positive electrode side second gasket, 720a... base, 720b... insertion hole, 720c... protrusion, 730... negative electrode side first gasket, 730a... first insertion part, 730b... second insertion part, 730c... insertion hole, 740... negative electrode side second gasket, 740a... base, 740b... insertion hole, 740c... protrusion, 800... charging / discharging body, 821b... negative electrode tab (tab), 900... charging / discharging body, 900p... flat part, 1100... charging / discharging body, 1110... positive electrode,1112... Positive electrode active material layer, 1113... Heat-resistant insulating layer, X... Longitudinal direction, Y... Shortitudinal direction, Z... Height direction,

Claims

1. A battery comprising: a charge / discharge body having a positive electrode, a negative electrode, and an insulating member provided between the positive electrode and the negative electrode stacked on top of each other; a positive electrode conductive member; and a negative electrode conductive member, wherein the insulating member is insulating; the positive electrode has a positive electrode current collector and a plurality of positive electrode tabs which are a plurality of tabs protruding from the positive electrode current collector; the negative electrode has a negative electrode current collector and a plurality of negative electrode tabs which are a plurality of tabs protruding from the negative electrode current collector; the plurality of positive electrode tabs are joined to the positive electrode conductive member in a bundled state; the plurality of negative electrode tabs are joined to the negative electrode conductive member in a bundled state; and at least one of the plurality of positive electrode tabs and the plurality of negative electrode tabs includes a tab on one side of the charge / discharge body that is wider than the tab on the other side.

2. The battery according to claim 1, wherein the charge / discharge body is a wound body in which at least the positive electrode and the negative electrode are wound with the insulating member in between.

3. The battery according to claim 2, wherein at least one of the plurality of positive electrode tabs and the plurality of negative electrode tabs is arranged such that the width of the charge / discharge body gradually widens from the outside to the inside, along the winding direction of the charge / discharge body.

4. The battery according to claim 2, wherein at least one of the plurality of positive electrode tabs and the plurality of negative electrode tabs is arranged such that the width of the charge / discharge body gradually widens from the inside outward along the winding direction of the charge / discharge body.

5. The battery according to claim 2, wherein the positive electrode current collector and the positive electrode tab comprise aluminum, the negative electrode current collector and the negative electrode tab comprise copper, and the plurality of positive electrode tabs are arranged such that the width along the winding direction of the charge / discharge body gradually widens from one side of the charge / discharge body to the other.

6. The battery according to claim 2, wherein at least one of the plurality of positive electrode tabs and the plurality of negative electrode tabs is arranged such that the width of the charge / discharge body gradually widens from the outside to the inside of the charge / discharge body along the winding direction of the charge / discharge body, and the width of the tabs arranged on the outside of the charge / discharge body is contained within the width range of the tabs arranged on the inside of the charge / discharge body.

7. The battery according to claim 2, wherein at least one of the plurality of positive electrode tabs and the plurality of negative electrode tabs is arranged such that the width of the charge / discharge body gradually widens from the inside to the outside of the charge / discharge body along the winding direction of the charge / discharge body, and the width of the tabs arranged inside the charge / discharge body is contained within the width range of the tabs arranged outside the charge / discharge body.

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