WO2021171334A1 - Connection lead and battery - Google Patents

Abstract

According to an embodiment, provided is a connection lead that connects a current collector tab of an electrode group and an electrode terminal in a battery. The connection lead comprises a top plate and a pair of legs. The pair of legs, relative to the top plate, bend together toward the same side in the thickness direction of the top plate. In the connection lead, leg connecting parts of the pair of legs are connected to the top plate at positions that are set apart from each other by a first distance in the width direction of the top plate. In each of the pair of legs, an extension part is provided at a position that is set apart toward the side opposite the top plate with respect to the leg connecting part, and between the extension parts of the pair of legs is a second distance that is smaller than the first distance.

Description

Connection leads and batteries

Embodiments of the present invention relate to connection leads and batteries.

In recent years, secondary batteries such as lithium-ion secondary batteries have been installed in electric vehicles, hybrid vehicles, electric motorcycles, forklifts, and the like. Batteries such as secondary batteries are required to have high output and long life, and are required to have high impact resistance against external force and vibration.

As a battery such as a secondary battery, there is a battery in which an electrode group having a positive electrode and a negative electrode is housed in an internal cavity of an outer container. In this battery, the outer container includes a bottom wall and a peripheral wall, and a lid member is attached to the peripheral wall of the outer container at an end opposite to the bottom wall. Then, the internal cavity of the outer container is closed by the lid member. Further, in the battery, the electrode terminals are attached to the outer surface of the lid member, and the current collecting tab protrudes in the electrode group of the internal cavity. Then, the current collecting tab is electrically connected to the electrode terminal via the connection lead (lead).

In the above-mentioned batteries, it is required that the rigidity of the connection lead is ensured high. The connecting leads also form a current path between the electrode group and the electrode terminals. Therefore, it is required that the electric resistance of the connection lead is kept low.

Japanese Patent Application Laid-Open No. 2011-71109

An object to be solved by the present invention is to provide a connection lead in which high rigidity is ensured and low electrical resistance is ensured, and a battery having the connection lead.

According to the embodiment, a connection lead for connecting between the current collecting tab of the electrode group and the electrode terminal in the battery is provided. The connecting lead includes a top plate portion and a pair of legs, and the pair of legs bends with respect to the top plate portion in the same side with respect to each other in the thickness direction of the top plate portion. The first leg portion, which is one of the pair of leg portions, includes a first leg connecting portion and a first extending portion, and the first leg connecting portion is connected to the top plate portion. The first extension portion is located on the side opposite to the top plate portion with respect to the first leg connection portion. The second leg, which is the other of the pair of legs, includes a second leg connection and a second extension, and the second leg connection is the first leg in the width direction of the top plate. It is connected to the top plate at a position first distance away from the connection. The second extension portion is located on the side opposite to the top plate portion with respect to the second leg connection portion, and is different from the first extension portion of the first leg portion in the width direction of the top plate portion. Have a second distance between them, which is smaller than the first distance.

According to the embodiment, the battery includes the above-mentioned connection lead, outer container, electrode group, lid member, and electrode terminal. The outer container includes a bottom wall and a peripheral wall, and the inner cavity in which the connecting lead is arranged is defined by the bottom wall and the peripheral wall. The electrode group comprises a positive electrode and a negative electrode, and includes a current collecting tab that is joined to the connecting lead at least one of the first extension portion of the first leg portion and the second extension portion of the second leg portion. .. The lid member is attached to the peripheral wall at the end opposite to the bottom wall and closes the opening of the inner cavity of the outer container. The electrode terminal is attached to the outer surface of the lid member and is connected to the top plate portion of the connection lead.

FIG. 1 is a perspective view schematically showing a battery according to the first embodiment. FIG. 2 is a perspective view schematically showing a state in which the battery according to the first embodiment is disassembled for each member. FIG. 3 is a schematic view illustrating an example of a method for manufacturing a battery electrode group according to the first embodiment. FIG. 4 is a perspective view showing the configuration of the connection lead according to the first embodiment. FIG. 5 is a cross-sectional view schematically showing a connection lead and a portion in the vicinity thereof in the battery according to the first embodiment. FIG. 6 is a schematic view illustrating an example of a method for manufacturing a connecting lead according to the first embodiment. FIG. 7 is a perspective view showing the configuration of the connection lead according to the first modification. FIG. 8 is a cross-sectional view schematically showing a joint portion of the connection lead according to the second modification with the current collecting tab and its vicinity. FIG. 9 is a cross-sectional view schematically showing a joint portion of the connection lead according to the third modification with the current collecting tab and its vicinity. FIG. 10 is a cross-sectional view schematically showing a joint portion of the connection lead according to the fourth modification with the current collecting tab and its vicinity. FIG. 11 is a cross-sectional view schematically showing a joint portion of the connection lead according to the fifth modification with the current collecting tab and its vicinity. FIG. 12 is a cross-sectional view schematically showing a joint portion of the connection lead according to the sixth modification with the current collecting tab and its vicinity. FIG. 13 is a cross-sectional view schematically showing a joint portion of the connection lead according to the seventh modification with the current collecting tab and its vicinity. FIG. 14 is a cross-sectional view schematically showing a joint portion of the connection lead according to the eighth modification with the current collecting tab and its vicinity. FIG. 15 is a cross-sectional view schematically showing a joint portion of the connection lead according to the ninth modification with the current collecting tab and its vicinity. FIG. 16 is a cross-sectional view schematically showing a joint portion of the connection lead according to the tenth modification with the current collecting tab and its vicinity. FIG. 17 is a cross-sectional view schematically showing a joint portion of the connection lead according to the eleventh modification with the current collecting tab and its vicinity. FIG. 18 is a cross-sectional view schematically showing a joint portion of the connection lead according to the twelfth modification with the current collecting tab and its vicinity.

Hereinafter, embodiments will be described with reference to the drawings.

(First Embodiment)
1 and 2 show the battery 1 according to the first embodiment. As shown in FIGS. 1 and 2, the battery 1 includes an electrode group 2, an outer container 3, and a lid member 5. Each of the outer container 3 and the lid member 5 is formed of a metal such as aluminum, aluminum alloy, iron, copper or stainless steel. Here, in the battery 1, the vertical direction (direction indicated by the arrow X1 and the arrow X2), the horizontal direction (vertical or substantially vertical) intersecting the vertical direction (direction indicated by the arrow Y1 and the arrow Y2), and the vertical direction. Height directions (directions indicated by arrows Z1 and Z2) that intersect (vertical or substantially vertical) with respect to both directions and lateral directions are defined. In each of the battery 1 and the outer container 3, the dimensions in the vertical direction are smaller than the dimensions in the horizontal direction and the dimensions in the height direction, respectively.

The outer container 3 includes a bottom wall 6 and a peripheral wall 7. The internal cavity 8 in which the electrode group 2 is housed is defined by the bottom wall 6 and the peripheral wall 7. In the outer container 3, the inner cavity 8 opens in the height direction toward the side opposite to the side where the bottom wall 6 is located. The peripheral wall 7 includes two pairs of side walls 11 and 12. The pair of side walls 11 face each other with the internal cavity 8 interposed therebetween in the lateral direction. The pair of side walls 12 face each other with the inner cavity 8 interposed therebetween in the vertical direction. Each of the side walls 11 extends continuously along the longitudinal direction between the side walls 12. Each of the side walls 12 extends continuously along the lateral direction between the side walls 11. The lid member 5 is attached to the peripheral wall 7 at the end opposite to the bottom wall 6. Therefore, the lid member 5 closes the opening of the inner cavity 8 of the outer container 3. The lid member 5 and the bottom wall 6 face each other with the internal cavity 8 interposed therebetween in the height direction.

FIG. 3 is a diagram illustrating an example of a manufacturing method of the electrode group 2. As shown in FIG. 3 and the like, the electrode group 2 includes a positive electrode 13 and a negative electrode 14. In the electrode group 2, the separator 15 is interposed between the positive electrode 13 and the negative electrode 14. The separator 15 is formed of a material having an electrically insulating property, and electrically insulates the positive electrode 13 from the negative electrode 14.

The positive electrode 13 includes a positive electrode current collector 13A such as a positive electrode current collector foil, and a positive electrode active material-containing layer 13B supported on the surface of the positive electrode current collector 13A. The positive electrode current collector 13A is not limited to these, but is, for example, an aluminum foil or an aluminum alloy foil, and has a thickness of about 10 μm to 20 μm. The positive electrode active material-containing layer 13B includes a positive electrode active material, and may optionally contain a binder and a conductive agent. Examples of the positive electrode active material include, but are not limited to, oxides, sulfides, polymers, and the like that can occlude and release lithium ions. The positive electrode current collector 13A includes a positive electrode current collector tab 13C as a portion where the positive electrode active material-containing layer 13B is not supported.

The negative electrode 14 includes a negative electrode current collector 14A such as a negative electrode current collector foil, and a negative electrode active material-containing layer 14B supported on the surface of the negative electrode current collector 14A. The negative electrode current collector 14A is not limited to these, but is, for example, an aluminum foil, an aluminum alloy foil, a copper foil, or the like, and has a thickness of about 10 μm to 20 μm. The negative electrode active material-containing layer 14B includes a negative electrode active material, and may optionally contain a binder and a conductive agent. The negative electrode active material is not particularly limited, and examples thereof include metal oxides, metal sulfides, metal nitrides, and carbon materials capable of occluding and releasing lithium ions. The negative electrode current collector 14A includes a negative electrode current collector tab 14C as a portion where the negative electrode active material-containing layer 14B is not supported.

In the electrode group 2 of the present embodiment, the positive electrode 13, the negative electrode 14, and the separator 15 are centered on the winding shaft B with the separator 15 sandwiched between the positive electrode active material-containing layer 13B and the negative electrode active material-containing layer 14B. It is turned around as. In the electrode group 2, the positive electrode 13, the separator 15, the negative electrode 14, and the separator 15 are wound in this order. Further, in the electrode group 2, the positive electrode current collecting tab 13C projects with respect to the negative electrode 14 and the separator 15. Then, the negative electrode current collecting tab 14C projects to the positive electrode 13 and the separator 15 in the direction opposite to the protruding direction of the positive electrode current collecting tab 13C. In the present embodiment, the positive electrode current collecting tab 13C protrudes to one side in the axial direction (arrows Y3 and arrow Y4) along the winding axis B, and the negative electrode current collecting tab 14C collects positive electrodes in the direction along the winding axis B. The electric tab 13C protrudes to the side opposite to the protruding side.

In the electrode group 2, the width direction (vertical or substantially vertical) intersecting (vertical or substantially vertical) with respect to the axial direction (protruding direction of the current collecting tabs 13C and 14C), and the axial direction and the width direction. The thickness directions (directions indicated by arrows X3 and X4) that intersect with each other are defined. Then, in the electrode group 2, the dimensions in the thickness direction are smaller than the dimensions in the axial direction and the dimensions in the width direction, respectively. Therefore, the electrode group 2 is formed in a flat shape. In the electrode group 2 of an example such as FIG. 2, the dimension in the axial direction is larger than the dimension in the width direction.

Further, when the electrode group 2 is formed by winding around the winding axis B as described above, for example, in a state where the electrode group 2 is being manufactured as shown in FIG. 3, the positive electrode current collecting tab 13C and the negative electrode group are collected. A curved surface portion 17 is formed on each of the electric tabs 14C. In each of the current collecting tabs 13C and 14C, curved surface portions 17 are formed at both end portions in the width direction of the electrode group 2.

In the electrode group 2 of an example such as FIG. 2, each of the positive electrode current collecting tab 13C and the negative electrode current collecting tab 14C includes a binding portion 18 in which a plurality of strip-shaped portions are bundled. In the present embodiment, in each of the current collecting tabs 13C and 14C, a binding portion 18 is formed at the central portion in the width direction of the electrode group 2. The binding portion 18 presses the central portions of the current collecting tabs 13C and 14C in the width direction of the electrode group 2 inward in the thickness direction of the electrode group 2, for example, from the state shown in FIG. ,It is formed. Since the binding portion 18 is formed as described above, each of the binding portions 18 has a smaller dimension in the thickness direction of the electrode group 2 than a portion other than the binding portion 18 of the electrode group 2. Further, in the electrode group 2 of the example of FIG. 2 and the like, only one binding portion 18 is formed on each of the current collecting tabs 13C and 14C, and a plurality of strip-shaped portions are formed on each of the current collecting tabs 13C and 14C. It is united in one place of 18.

Further, in the production of the electrode group 2 of the example shown in FIG. 2, after forming the binding portion 18 on each of the current collecting tabs 13C and 14C, the binding portions 18 are bound in the width direction of the electrode group 2 on each of the current collecting tabs 13C and 14C. The portions on both sides of the portion 18 are cut from the electrode group 2. Therefore, the curved surface portions 17 and the like formed on the current collecting tabs 13C and 14C in the state of FIG. 3 and the like are cut from the electrode group 2.

In an example such as FIG. 2, the electrode group 2 is arranged in the internal cavity 8 in a state where the winding shaft B (axial direction) is parallel or substantially parallel to the lateral direction of the battery 1. Further, the electrode group 2 is arranged in the internal cavity 8 in a state where the width direction coincides with or substantially coincides with the height direction of the battery 1 and the thickness direction coincides with or substantially coincides with the vertical direction of the battery 1. .. Then, in the inner cavity 8 of the outer container 3, the binding portion 18 of the positive electrode current collecting tab 13C projects to one side in the lateral direction with respect to the negative electrode 14 and the separator 15. Further, the negative electrode current collecting tab 14C projects laterally to the positive electrode 13 and the separator 15 on the side opposite to the side on which the positive electrode current collecting tab 13C protrudes.

Further, the electrode group 2 does not need to have a winding structure in which the positive electrode, the negative electrode and the separator are wound. In one example, the electrode group 2 has a stack structure in which a plurality of positive electrodes and a plurality of negative electrodes are alternately laminated, and a separator is provided between the positive electrode and the negative electrode. Also in this case, in the electrode group 2, the positive electrode current collecting tab protrudes from the negative electrode and the separator, and the negative electrode current collecting tab protrudes from the positive electrode and the separator on the side opposite to the side on which the positive electrode current collecting tab protrudes. Further, in the electrode group 2, the width direction intersects the protruding direction of the current collecting tab (vertical or substantially vertical), and the electrode group 2 intersects both the protruding direction and the width direction of the current collecting tab (vertical or substantially vertical). The (vertical) thickness direction is defined. Then, in the electrode group 2, the dimensions in the thickness direction are smaller than the dimensions in the protruding direction and the dimensions in the width direction of the current collecting tab.

Even in this example, each of the positive electrode current collecting tab and the negative electrode current collecting tab includes a binding portion 18 in which a plurality of strip-shaped portions are bundled. In each of the current collecting tabs, a binding portion 18 is formed at least in the central portion in the width direction of the electrode group 2. Further, also in this example, the positive electrode current collecting tab protrudes to one side in the lateral direction of the battery 1 (outer container 3) with respect to the negative electrode. Then, in the electrode group 2, the negative electrode current collecting tab protrudes with respect to the positive electrode in the lateral direction of the battery 1 to the side opposite to the side on which the positive electrode current collecting tab protrudes. Further, also in this example, the electrode group 2 has an internal cavity 8 in a state in which the width direction coincides with or substantially coincides with the height direction of the battery 1 and the thickness direction coincides with or substantially coincides with the vertical direction of the battery 1. Is placed in.

Further, in the internal cavity 8, an electrolytic solution (not shown) is held (impregnated) in the electrode group 2. The electrolytic solution may be a non-aqueous electrolytic solution in which an electrolyte is dissolved in an organic solvent, or an aqueous electrolytic solution such as an aqueous solution. Instead of the electrolytic solution, a gel-like electrolyte may be used, or a solid electrolyte may be used. When a solid electrolyte is used as the electrolyte, in the electrode group, the solid electrolyte is interposed between the positive electrode 13 and the negative electrode 14 instead of the separator 15. In this case, the solid electrolyte electrically insulates the positive electrode 13 from the negative electrode 14.

In the battery 1, a pair of electrode terminals 21 are attached to the outer surface (upper surface) of the lid member 5 of the outer container 3. The electrode terminal 21 is formed of a conductive material such as metal. One of the electrode terminals 21 is the positive electrode terminal of the battery 1, and the other of the electrode terminals 21 is the negative electrode terminal of the battery 1. An insulating member 22 is provided between each of the electrode terminals 21 and the lid member 5. Each of the electrode terminals 21 is electrically insulated from the outer container 3 including the lid member 5 by the insulating member 22.

A pair of connecting leads 20 are arranged in the inner cavity 8 of the outer container 3. The positive electrode current collecting tab 13C of the electrode group 2 is electrically connected to the corresponding positive electrode terminal of the electrode terminal 21 via the corresponding positive electrode side connection lead (positive electrode lead) of the connection lead (lead) 20. Connected to. Further, the negative electrode current collecting tab 14C of the electrode group 2 electrically connects to the corresponding negative electrode terminal of the electrode terminal 21 via the corresponding negative electrode side connection lead (negative electrode lead) of the connection lead 20. Be connected. Each of the connecting leads 20 is formed of a conductive material such as metal. Examples of the conductive material forming the connecting lead 20 include aluminum, stainless steel, copper and iron.

Further, in the inner cavity 8 of the outer container 3, a pair of insulating guards 23 and an electrode retainer 25 are arranged. Each of the insulating guards 23 is formed of a material having electrical insulating properties. Each of the positive electrode side connecting lead and the positive electrode current collecting tab 13C, which is one of the connecting leads 20, is prevented from coming into contact with the outer container 3 by the corresponding one of the insulating guards 23, and is electrically connected to the outer container 3. Insulated into. Further, each of the negative electrode side connecting lead, which is one of the connecting leads 20, and the negative electrode current collecting tab 14C, each of the negative electrode current collecting tab 14C is prevented from coming into contact with the outer container 3 by the corresponding one of the insulating guards 23. It is electrically insulated.

Further, the electrode retainer 25 is arranged between the electrode group 2 and the lid member 5 in the height direction of the battery 1. The electrode retainer (internal insulating member) 25 is formed of a material having electrical insulating properties. The positive electrode current collecting tab 13C, the negative electrode current collecting tab 14C, and the pair of connecting leads 20 are prevented from coming into contact with the lid member 5 by the electrode retainer 25, and are electrically insulated from the lid member 5.

Further, in the example of FIGS. 1 and 2, the gas release valve 26 and the liquid injection port 27 are formed on the lid member 5. Then, a sealing plate 28 that closes the liquid injection port 27 is welded to the outer surface of the lid member 5. The gas release valve 26, the liquid injection port 27, and the like may not be provided in the battery 1.

FIG. 4 shows the configuration of the connection lead 20, and FIG. 5 shows the connection lead 20 and the portion in the vicinity thereof in the battery 1. FIG. 5 shows the connection state of the connection lead 20 to the current collection tab (corresponding one of 13C and 14C). As shown in FIGS. 4 and 5, each of the connection leads 20 includes a top plate portion 31 and a pair of leg portions 32A and 32B. The top plate portion 31 has extension ends E1 and E2, and the top plate portion 31 extends along the extension direction (directions indicated by arrows Y5 and Y6) from the extension end E1 to the extension end E2. Will be done. Further, in the top plate portion 31, the width direction (vertical or substantially vertical) intersecting (vertical or substantially vertical) with respect to the extension direction (longitudinal direction), the extension direction (longitudinal direction), and the extension direction (longitudinal direction). Thickness directions (directions indicated by arrows Z5 and Z6) that intersect both width directions are defined.

The top plate portion 31 is formed from the top plate constituent portions 33 and 35. In the top plate portion 31, the top plate constituent portion (first top plate constituent portion) 33 forms the extended end E1. Then, the top plate constituent portion (second top plate constituent portion) 35 is adjacent to the top plate constituent portion 33 on the side where the extension end E2 is located. Further, in the top plate portion 31, the top plate constituent portion 35 forms the extended end E2. The dimension (width) in the width direction of the top plate portion 31 in the top plate constituent portion 33 is larger than the dimension (width) in the width direction of the top plate portion 31 in the top plate constituent portion 35. The top plate portion 31 is formed plane-symmetrically or substantially plane-symmetrically with the central plane in the width direction as the center. Further, the top plate constituent portion 33 is formed with a through hole 36 that penetrates the top plate constituent portion 33 in the thickness direction of the top plate portion 31.

The leg portion (first leg portion) 32A includes a leg connecting portion (first leg connecting portion) 41A connected to the top plate constituent portion 35 of the top plate portion 31, and the leg portion (second leg portion). 32B includes a leg connecting portion (second leg connecting portion) 41B connected to the top plate constituent portion 35 of the top plate portion 31. In the top plate constituent portion 35, the leg connecting portion 41A of the leg portion 32A is connected to one edge in the width direction of the top plate portion 31, and the connection position of the leg connecting portion 41A in the width direction of the top plate portion 31 is The leg connecting portion 41B of the leg portion 32B is connected to the opposite edge. Therefore, the leg connecting portions 41A and 41B are connected to the top plate portion 31 at positions separated from each other in the width direction of the top plate portion 31. The connection position of the leg connection portion 41A to the top plate portion 31 is separated by a distance (first distance) L1 in the width direction of the top plate portion 31 with respect to the connection position of the leg connection portion 41B to the top plate portion 31.

The leg portion 32A bends with respect to the top plate portion 31 with the leg connecting portion 41A as the bending position. The leg portion 32A bends to one side in the thickness direction of the top plate portion 31 with respect to the top plate portion 31. Further, the leg portion 32B bends with respect to the top plate portion 31 with the leg connecting portion 41B as the bending position. The leg portion 32B bends with respect to the top plate portion 31 toward the side where the leg portion 32A bends in the thickness direction of the top plate portion 31. Therefore, the legs 32A and 32B are bent toward the same side with respect to each other in the thickness direction of the top plate portion 31 and with respect to the top plate portion 31. Then, the legs 32A and 32B project from the top plate 31 toward the same side with respect to each other in the thickness direction of the top plate 31.

Since the pair of legs 32A and 32B are formed as described above, the connection lead 20 is formed in a bifurcated shape. The bending lines formed in each of the leg connecting portions 41A and 41B are along the extending direction (longitudinal direction) of the top plate portion 31. The bending lines formed in each of the leg connecting portions 41A and 41B intersect with each other in both the width direction of the top plate portion 31 and the thickness direction of the top plate portion 31 (become vertical or substantially vertical). .. Further, the width direction (plate width direction) of each of the leg portions 32A and 32B coincides with or substantially coincides with the extension direction (longitudinal direction) of the top plate portion 31. The width directions of the legs 32A and 32B intersect with each other with respect to both the width direction of the top plate portion 31 and the thickness direction of the top plate portion 31 (become vertical or substantially vertical).

The leg portion (first leg portion) 32A includes an extension portion (first extension portion) 42A located on the side opposite to the top plate portion 31 with respect to the leg connection portion 41A. The extension portion 42A is provided at a position distal to the top plate portion 31 as compared with the leg connection portion 41A. Further, the leg portion (second leg portion) 32B includes an extension portion (second extension portion) 42B located on the side opposite to the top plate portion 31 with respect to the leg connection portion 41B. The extension portion 42B is provided at a position distal to the top plate portion 31 as compared with the leg connection portion 41B. Each of the extension portions 42A and 42B is extended along the thickness direction of the top plate portion 31, and each extension direction (longitudinal direction) of the extension portions 42A and 42B is the thickness of the top plate portion 31. Matches or substantially matches the direction. The thickness direction (plate thickness direction) of each of the extension portions 42A and 42B coincides with or substantially coincides with the width direction of the top plate portion 31.

The extension portion 42B faces the extension portion 42A from one side in the width direction of the top plate portion 31. The extension portion (second extension portion) 42B has a distance (second distance) L2 between the extension portion (second extension portion) 42A and the extension portion (first extension portion) 42A in the width direction of the top plate portion 31. The distance L2 may be smaller than the distance L1 and the distance L2 may be zero. When the distance L2 is zero, the top plate portion 31 comes into contact with the extension portion 42A from one side in the width direction. Since the distances L1 and L2 are the same as described above, the legs 32A and 32B are closer to each other between the extension portions 42A and 42B than between the leg connection portions 41A and 41B.

In the leg portion 32A, the leg connection portion 41A and the extension portion 42A are relayed via the relay unit (first relay unit) 43A1 and 43A2. In the present embodiment, the relay portions 43A1 and 43A2 are arranged in order from the proximal side with respect to the leg connecting portion 41A. In the leg portion 32B, between the leg connecting portion 41B and the extension portion 42B is relayed via the relay portion (second relay portion) 43B1 and 43B2. In the present embodiment, the relay portions 43B1 and 43B2 are arranged in order from the proximal side with respect to the leg connecting portion 41B.

The relay portion 43A1 extends from the leg connecting portion 41A along the thickness direction of the top plate portion 31, and the relay portion 43B1 extends from the leg connecting portion 41B along the thickness direction of the top plate portion 31. .. Therefore, the extending directions (longitudinal directions) of the relay portions 43A1 and 43B1 coincide with or substantially coincide with the thickness direction of the top plate portion 31. Further, in the present embodiment, the bending angle of the relay portion 43A1 (leg portion 32A) at the leg connecting portion 41A with respect to the top plate portion 31 is 90 degrees or approximately 90 degrees, and the relay portion 43B1 (legs) at the leg connecting portion 41B. The bending angle of the portion 32B) with respect to the top plate portion 31 is 90 degrees or approximately 90 degrees. The thickness direction (plate thickness direction) of each of the relay portions 43A1 and 43B1 coincides with or substantially coincides with the width direction of the top plate portion 31. The relay portion 43B1 faces the relay portion 43A1 from one side in the width direction of the top plate portion 31. The distance between the relay portions 43A1 and 43B1 in the width direction of the top plate portion 31 is larger than the distance L2 between the extension portions 42A and 42B in the width direction of the top plate portion 31.

The relay unit 43A2 is connected to the relay unit 43A1 at the bending position 45A1 and is connected to the extension unit 42A at the bending position 45A2. In the present embodiment, the relay portion 43A2 forms a bent portion (first bent portion) that bends with respect to the relay portion 43A1 and the extending portion 42A. The relay portion 43A2 bends with respect to the relay portion 43A1 toward the side closer to the leg portion 32B at the bending position 45A1. Then, the relay portion 43A2 bends at the bending position 45A2 with respect to the extending portion 42A toward the side away from the leg portion 32B. The bending angle of the relay portion 43A2 at the bending position 45A1 with respect to the relay portion 43A1 and the bending angle of the relay portion 43A2 at the bending position 45A2 with respect to the extending portion 42A are larger than 0 degrees and 90 degrees. Less than a degree. Since the relay portion 43A2 is formed as described above, the relay portion 43A2 is inclined with respect to the extension portion 42A so that the portion closer to the extension portion (first extension portion) 42A is closer to the leg portion 32B. do.

The relay unit 43B2 is connected to the relay unit 43B1 at the bending position 45B1 and is connected to the extension unit 42B at the bending position 45B2. In the present embodiment, the relay portion 43B2 forms a bent portion (second bent portion) that bends with respect to the relay portion 43B1 and the extension portion 42B. The relay portion 43B2 bends with respect to the relay portion 43B1 toward the side closer to the leg portion 32A at the bending position 45B1. Then, the relay portion 43B2 bends at the bending position 45B2 with respect to the extending portion 42B toward the side away from the leg portion 32A. The bending angle of the relay portion 43B2 at the bending position 45B1 with respect to the relay portion 43B1 and the bending angle of the relay portion 43B2 at the bending position 45B2 with respect to the extension portion 42B are larger than 0 degrees and 90 degrees. Less than a degree. Since the relay portion 43B2 is formed as described above, the relay portion 43B2 is inclined with respect to the extension portion 42B so that the portion closer to the extension portion (second extension portion) 42B is closer to the leg portion 32A. do.

The relay unit 43B2 faces the relay unit 43A2 from one side in the width direction of the top plate unit 31. The distance between the relay portions 43A2 and 43B2 in the width direction of the top plate portion 31 is larger than the distance L2 between the extension portions 42A and 42B in the width direction of the top plate portion 31. In the relay portions 43A2 and 43B2, the closer to the extending portions 42A and 42B, the smaller the distance of the top plate portion 31 to each other in the width direction.

In the leg portion (first leg portion) 32A, an end plate portion (first end plate portion) 47A is provided on the side opposite to the top plate portion 31 with respect to the extension portion 42A. The end plate portion 47A forms a protruding end of the leg portion 32A from the top plate portion 31, that is, an end of the leg portion 32A opposite to the top plate portion 31. Further, in the leg portion (second leg portion) 32B, an end plate portion (second end plate portion) 47B is provided on the side opposite to the top plate portion 31 with respect to the extension portion 42B. The end plate portion 47B forms a protruding end of the leg portion 32B from the top plate portion 31, that is, an end of the leg portion 32B opposite to the top plate portion 31.

The end plate portion 47A is connected to the extension portion 42A at the bending position 48A. Then, the end plate portion 47A bends with respect to the extending portion 42A toward the side away from the leg portion 32B at the bending position 48A. Therefore, the end plate portion 47A is inclined with respect to the extending portion 42A so that the portion closer to the protruding end of the leg portion 32A is separated from the leg portion 32B. Further, the end plate portion 47B is connected to the extension portion 42B at the bending position 48B. Then, the end plate portion 47B bends with respect to the extending portion 42B toward the side away from the leg portion 32A at the bending position 48B. Therefore, the end plate portion 47B is inclined with respect to the extending portion 42B so that the portion closer to the protruding end of the leg portion 32B is separated from the leg portion 32A. The bending angle of the end plate portion 47A with respect to the extending portion 42A at the bending position 48A and the bending angle of the end plate portion 47B with respect to the extending portion 42B at the bending position 48B are larger than 0 degrees. And it is smaller than 90 degrees. In the end plate portions 47A and 47B, the closer to the extending portions 42A and 42B, the smaller the distance of the top plate portion 31 to each other in the width direction.

Further, in the present embodiment, the thin plate portion 50 is formed in the leg portion 32A from the extending portion 42A to the protruding end. That is, the thin plate portion 50 is formed over a part of the extending portion 42A and the entire end plate portion 47A. The thin plate portion 50 has a smaller thickness (plate thickness) than other portions of the connecting lead 20, that is, the top plate portion 31, the leg portion 32B, and the leg portion 32A. Therefore, the thickness of the leg portion 32A in the thin plate portion 50 is smaller than the thickness of the leg portion 32A between the top plate portion 31 and the thin plate portion 50. In one example, the thickness of the connecting lead 20 is 2.0 mm to 3.0 mm at a portion other than the thin plate portion 50. Then, the thin plate portion 50 has a thickness of −0.5 mm to −1.0 mm with respect to other portions of the connection lead 20.

Further, on the surface of the extension portion 42A facing the side where the leg portion 32B is located, a step 51 is formed at the boundary between the thin plate portion 50 and a portion other than the thin plate portion 50. On the surface of the extension portion 42A facing the side where the leg portion 32B is located, the surface of the thin plate portion 50 is located on the side opposite to the leg portion 32B with respect to the surface of the portion other than the thin plate portion 50 due to the step 51. .. No step or the like is formed at the boundary between the thin plate portion 50 and the portion other than the thin plate portion 50 on the surface of the extended portion 42A facing the side opposite to the leg portion 32B.

Further, in the present embodiment, except that the thin plate portion 50 is formed on the leg portion 32A, the leg portions 32A and 32B are mutually centered on the central surface of the connection lead 20 in the width direction of the top plate portion 31. On the other hand, it is formed plane-symmetrically or substantially plane-symmetrically. The connection lead 20 is formed plane-symmetrically or substantially plane-symmetrically with the central plane in the width direction of the top plate portion 31 as the center, except that the thin plate portion 50 is formed on the leg portion 32A.

FIG. 6 is a diagram illustrating an example of a method for manufacturing the connection lead 20. In one example of FIG. 6, the connecting lead 20 is formed from one plate member 60. The plate member 60 includes parts 61, 62A, 62B. When forming the connection lead 20, the portion 62A is bent with respect to the portion 61 at the bending position 63A by bending. At this time, the portion 62A is bent with respect to the portion 61 toward one side in the thickness direction (plate thickness direction) of the portion 61. Further, by bending, the portion 62B is bent with respect to the portion 61 at the bending position 63B. At this time, the part 62B is bent with respect to the part 61 toward the side where the part 62A is bent in the thickness direction of the part 61. As a result, the top plate portion 31 is formed by the portion 61.

Further, the bending position 45A1, 45A2, 48A is formed at the portion 62A by the bending process, and the thin plate portion 50 is formed at the portion 62A by the crushing process. As a result, the leg portion 32A is formed by the portion 62A. Further, the bending positions 45B1, 45B2, 48B are formed at the portion 62B by the bending process. As a result, the leg portion 32B is formed by the portion 62B.

Further, in another example, the top plate portion 31, the leg portions 32A, and 32B are formed from different members with respect to each other. Then, the connection lead 20 is formed by integrating the three members by welding or the like.

As shown in FIGS. 2 and 5, in the internal cavity 8 of the battery 1, each top plate portion 31 of the pair of connection leads 20 is located between the electrode group 2 and the electrode retainer 25 in the height direction of the battery 1. Is arranged in, and is sandwiched between the electrode group 2 and the electrode retainer 25. In each of the connection leads 20, the extending direction (longitudinal direction) of the top plate portion 31 coincides with or substantially coincides with the lateral direction of the battery 1, and the width direction (plate width direction) of the top plate portion 31 is that of the battery 1. Matches or substantially matches the vertical direction. Then, in each of the connection leads 20, the thickness direction (plate thickness direction) of the top plate portion 31 coincides with or substantially coincides with the height direction of the battery 1. In the battery 1, one of the electrode terminals 21, that is, the corresponding one of the positive electrode terminal and the corresponding negative electrode terminal, is connected to each of the top plate portions 31 of the pair of connection leads 20. In each of the connection leads 20, the corresponding one of the electrode terminals 21 is inserted into the through hole 36 of the top plate constituent portion 33. Then, one of the electrode terminals 21 is connected to each of the connection leads 20 by caulking and fixing in the through hole 36.

Further, in the internal cavity 8 of the battery 1, the legs 32A and 32B of the pair of connecting leads 20 are arranged between the corresponding one of the side walls 11 and the electrode group 2 in the lateral direction of the battery 1. In each of the connection leads 20, the width directions of the legs 32A and 32B coincide with or substantially coincide with the lateral direction of the battery 1. Further, in each of the connection leads 20, the legs 32A and 32B are arranged outside the through hole 36, that is, the corresponding connection position of the electrode terminal 21 in the lateral direction of the battery 1. Therefore, each top plate portion 31 of the connection lead 20 extends from one of the electrode terminals 21 to the connection position of the leg portions 32A and 32B toward the outside in the lateral direction of the battery 1.

Further, in each of the connection leads 20, each of the legs 32A and 32B bends with respect to the top plate 31 toward the side where the bottom wall 6 is located in the height direction of the battery 1. Then, in each of the connection leads 20, the leg portion 32B faces the leg portion 32A from one side in the vertical direction of the battery 1.

Further, in each of the connection leads 20, the extension portion (second extension portion) 42A of the leg portion (first leg portion) 32A and the extension portion (second extension portion) 32B of the leg portion (second leg portion) 32B. Corresponding one of the current collecting tabs 13C and 14C is connected to both of the extension portions) 42B. That is, in each of the connection leads 20, joint portions 55 with one of the current collector tabs 13C and 14C are formed on both of the extension portions 42A and 42B. In the present embodiment, a joint portion 55 is formed on the thin plate portion 50 in each of the extension portions 42A of the connection lead 20. Therefore, in the connection lead 20, the thickness (plate thickness) of the leg portion 32A at the joint portion 55 of the extension portion 42A is the thickness of the leg portion 32A between the top plate portion 31 and the joint portion 55 of the extension portion 42A. Compared to, it is small.

Further, in the present embodiment, the binding portions 18 of the current collecting tabs 13C and 14C are sandwiched between the corresponding extension portions 42A and 42B of the connection lead 20. That is, each of the binding portions 18 of the current collecting tabs 13C and 14C is joined to the joining portion 55 in a state of being sandwiched between the extending portion 42A of the leg portion 32A and the extending portion 42B of the leg portion 32B. It becomes a holding part. In the extension portion 42A (thin plate portion 50), the binding portion 18 comes into contact with the surface facing the side where the leg portion 32B is located. Then, in the extending portion 42A, a step 51 is formed on the surface facing the side where the binding portion 18 comes into contact.

Here, the work of joining the current collecting tab (13C or 14C) to the connection lead 20 will be described. Each of the current collector tabs 13C, 14C is bonded to the corresponding one of the connecting leads 20 by, for example, ultrasonic welding using an ultrasonic horn. In the work of joining the current collecting tab (13C or 14C) to the connecting lead 20, first, the binding portion 18 is arranged between the extending portion 42A of the leg portion 32A and the extending portion 42B of the leg portion 32B. At this time, the binding portion 18 is inserted between the protruding ends of the leg portions 32A and the protruding ends of the leg portions 32B, and between the leg portions 32A and 32B. In the present embodiment, the end plate portion 47A bends with respect to the extension portion 42A toward the side away from the leg portion 32B, and the end plate portion 47B bends with respect to the extension portion 42B toward the side away from the leg portion 32A. .. Therefore, the binding portion 18 can be easily inserted between the legs 32A and 32B, and the binding portion 18 can be easily arranged between the extending portions 42A and 42B.

Then, in a state where the binding portion 18 of the current collecting tab (13C or 14C) is sandwiched between the thin plate portion 50 of the extension portion 42A and the extension portion 42B, the ultrasonic horn is attached to the thin plate portion 50 of the extension portion 42A. To abut. At this time, the ultrasonic horn is brought into contact with the thin plate portion 50 from the side opposite to the leg portion 32B. Then, using the ultrasonic vibration transmitted by the ultrasonic horn, the current collecting tabs (13C or 14C) are joined to the connecting leads 20 by the extending portions 42A and 42B, and the thin plate portion 50 and the extending portion 42A of the extending portion 42A are extended. A joint portion 55 with a current collecting tab (13C or 14C) is formed in the portion 42B. In the present embodiment, since the thin plate portion 50 is provided on the extension portion 42A, the bondability of the current collecting tab (13C or 14C) to the extension portions 42A and 42B is improved. Therefore, the binding portion 18 of the current collecting tab (13C or 14C) is appropriately joined to the connecting lead 20 at the joining portion 55 of the extending portions 42A and 42B.

Since welding is performed with the binding portion 18 sandwiched between the extension portions 42A and 42B, the extension portions 42A and 42B bind the current collecting tabs (13C or 14C) without providing a backup lead. The exposure of the portion 18 is prevented. That is, even if the backup lead is not provided, the binding portion 18 of the current collecting tab (13C or 14C) is protected by the extending portions 42A and 42B in the welding using the ultrasonic horn.

In the connection lead 20 of the present embodiment, the connection position of the leg connection portion 41A to the top plate portion 31 is a distance in the width direction of the top plate portion 31 with respect to the connection position of the leg connection portion 41B to the top plate portion 31. (First distance) L1 away. The distance L1 has a certain size and is larger than the distance (second distance) L2 between the extending portions 42A and 42B. Therefore, it is possible to increase the width dimension of the top plate portion 31 in the portion of the top plate portion 31 to which the legs 32A and 32B are connected and in the vicinity thereof, that is, in the top plate constituent portion 35. By increasing the width direction dimension of the top plate portion 31 in the top plate constituent portion 35, a large cross-sectional area of the top plate portion 31 is secured in the top plate constituent portion 35. That is, by increasing the distance L1, the width of the top plate constituent portion 35 can be increased, and the cross-sectional area of the top plate constituent portion 35 can be increased. As described above, by ensuring a large cross-sectional area of the top plate portion 31 in the top plate constituent portion 35, the electrical resistance of the connection lead 20 is ensured low. As a result, low electrical resistance is ensured in the current path between each of the current collecting tabs 13C and 14C and the corresponding one of the electrode terminals 21.

Further, in the connection lead 20 of the present embodiment, the extension portion 42A is provided on the leg portion 32A away from the connection position to the top plate portion 31, and the leg portion 32B is separated from the connection position to the top plate portion 31. , The extension portion 42B is provided. Then, the distance (second distance) L2 is formed between the extension portions 42A and 42B. The distance L2 is smaller than the above-mentioned distance L1 and is small or zero. By reducing the distance L2 between the extending portions 42A and 42B, the rigidity of the connecting lead 20 is ensured to be high. Therefore, in the battery 1, the resistance of the connection leads 20 to each impact is improved.

Further, in the present embodiment, in the thin plate portion 50 of the extension portion 42A, the binding portion 18 of the current collecting tab (13C or 14C) is connected to the surface facing the side where the extension portion 42B is located. Then, on the surface of the extension portion 42A facing the side where the extension portion 42B is located (the side with which the binding portion 18 abuts), the thin plate portion 50 has the binding portion 18 (the side where the binding portion 18 abuts) with respect to other than the thin plate portion 50 due to the step 51. It is dented on the opposite side of the leg 32B). Therefore, the thickness of the binding portion 18 is absorbed by the recess of the thin plate portion 50 with respect to the portion other than the thin plate portion 50, and the distance L2 between the extending portions 42A and 42B can be further reduced. As a result, the rigidity of the connection lead 20 is further increased.

Further, in the connection lead 20 of the present embodiment, the relay portion 43A2 is provided between the leg connection portion 41A and the extension portion 42A in the leg portion 32A, and the relay portion 43A2 is inclined with respect to the extension portion 42A. Then, in the connection lead 20, a relay portion 43B2 is provided between the leg connection portion 41B and the extension portion 42B in the leg portion 32B, and the relay portion 43B2 is inclined with respect to the extension portion 42B. Therefore, in the internal cavity 8 of the battery 1, the relay portions 43A2 and 43B2 of the connection leads 20 are arranged in a state of being inclined with respect to the vertical direction and the height direction of the battery 1. Therefore, when the battery 1 is impacted from the vertical direction, the load acting on each of the connection leads 20 is dispersed and reduced by the relay units 43A2 and 43B2. As a result, in the battery 1, the resistance of the connection leads 20 to each impact is further improved.

Further, in the present embodiment, in each of the current collecting tabs 13C and 14C, a plurality of strip-shaped portions are bound to one place of the binding portion 18. Then, in each of the current collecting tabs 13C and 14C, the binding portion 18 in which a plurality of strip-shaped portions are bound in one place is joined to the corresponding one of the connection leads 20. Since each of the current collecting tabs 13C and 14C is connected to the corresponding one of the connection leads 20 in a state where the plurality of strips are bundled in one place, the electrode group is used in each of the current collecting tabs 13C and 14C of the battery 1. The stress (load) acting on the root of the protruding portion in 2 is reduced. As a result, the resistance of each of the current collecting tabs 13C and 14C is improved.

(Modification example)
Hereinafter, a modified example of the above-described first embodiment will be described. In the following modification, only the changed portion from the first embodiment will be described, and the description of the same portion as that of the first embodiment will be omitted.

In the first modification shown in FIG. 7, a wide portion 53 is formed in each of the connection leads 20. In the wide portion 53, the wide portion 53 is formed over the entire portion formed in the extension portion (first extension portion) 42A in the thin plate portion 50. The wide portion 53 has a larger width (plate width) than the leg portion 32B and the other portions of the leg portion 32A. Therefore, the width of the leg portion 32A in the wide portion 53 is larger than the width of the leg portion 32A between the top plate portion 31 and the wide portion 53. In one example, the width (plate width) of the leg portion 32A and the width of the leg portion 32B at a portion other than the wide portion 53 are 6.0 mm to 7.0 mm, respectively. Then, in the wide portion 53, the width becomes +0.5 mm to +1.0 mm with respect to other portions of the leg portion 32A. Further, in the wide portion 53, a through hole 36, which is a connection position of the electrode terminal 21, is located with respect to another portion of the leg portion 32A in the width direction of the leg portion 32A (extending direction of the top plate portion 31). Protrude to the side. Then, the wide portion 53 does not project in the width direction of the leg portion 32A to the side opposite to the side where the through hole 36 is located with respect to the other portion of the leg portion 32A.

Also in this modification, the binding portions 18 of the current collecting tabs 13C and 14C are sandwiched between the corresponding extension portions 42A and 42B of the connection lead 20. Then, in each of the connecting leads 20, joint portions 55 with the corresponding ones of the current collecting tabs 13C and 14C are formed on both of the extending portions 42A and 42B. In this modification, in the thin plate portion 50 of each extending portion 42A of the connecting lead 20, the joint portion 55 is formed at a portion where the wide portion 53 is formed. Therefore, in each of the connection leads 20, the width (plate width) of the leg portion 32A at the joint portion 55 of the extension portion 42A is the leg portion 32A between the top plate portion 31 and the joint portion 55 of the extension portion 42A. It is large compared to the width of. Further, in the internal cavity 8 of the battery 1, each wide portion 53 of the connection lead 20 projects in the lateral direction of the battery 1 toward the side where the electrode group 2 is located with respect to other portions of the leg portion 32A.

In this modification, the above-mentioned wide portion 53 is provided in a part of the thin plate portion 50. Therefore, even in the thin plate portion 50 of the leg portion 32A, the cross-sectional area of the leg portion 32A is secured to a certain size. Further, in each of the connection leads 20, a joint portion 55 with one of the current collector tabs 13C and 14C is formed in the wide portion 53. Therefore, in the joint portion 55, the contact area between each of the connection leads 20 and the corresponding one of the current collector tabs 13C and 14C becomes large. Therefore, in this modification, the electric resistance is secured to be more appropriately low in the current path between each of the current collecting tabs 13C and 14C and the corresponding one of the electrode terminals 21.

Further, in each of the connection leads 20, the wide portion 53 projects in the lateral direction of the battery 1 toward the side where the electrode group 2 is located with respect to other portions of the leg portion 32A. Therefore, even if the wide portion 53 is provided, the insertability of the assembly such as the electrode group 2 and the pair of connecting leads 20 into the internal cavity 8 of the outer container 3 is ensured at the time of manufacturing the battery 1.

In the above-described embodiment or the like, in each of the current collecting tabs 13C and 14C, the binding portion 18 in which a plurality of strip-shaped portions are bound in one place is joined to the corresponding one of the connection leads 20, but the present invention is limited to this. It's not a thing. Further, in the above-described embodiment or the like, in each of the connection leads 20, one of the corresponding binding portions 18 of the current collecting tabs 13C and 14C is sandwiched between the extension portions 42A and 42B, and the extension portions 42A and 42B are sandwiched between the extension portions 42A and 42B. A joint portion 55 with one of the current collector tabs 13C and 14C is formed on both of them, but the present invention is not limited to this.

For example, in the second modification shown in FIG. 8, in each of the current collecting tabs 13C and 14C, a plurality of strip-shaped portions are bound at two places, and each of the current collecting tabs 13C and 14C has two binding portions 18A, 18B is provided. In this modification, the binding portions (held portions) 18A and 18B are joined to the corresponding one of the connecting leads 20 in a state of being sandwiched between the extending portions 42A and 42B. Also in this modification, the connecting portions 55 with the corresponding ones of the current collecting tabs 13C and 14C are formed on both of the extending portions 42A and 42B in each of the connecting leads 20. In one example of FIG. 8, the binding portion 18B is sandwiched by the extending portions 42A and 42B at a position closer to the top plate portion 31 than the binding portion 18A. Further, in this modification, a joint portion 55 with each of the binding portions (holding portions) 18A and 18B is formed on the thin plate portion 50 in the extension portion 42A.

Further, in the connection lead 20 of the third modified example shown in FIG. 9, the end plate portion 47A and the bending position 48A are not formed on the leg portion 32A, and the extension portion (first extension portion) 42A is formed. A protruding end of the leg portion 32A from the top plate portion 31 is formed. Then, the end plate portion 47B and the bent position 48B are not formed on the leg portion 32B, and the extension portion (second extension portion) 42B forms a protruding end of the leg portion 32B from the top plate portion 31. .. Further, in this modification, the thin plate portion 50 is not formed on the extending portion 42A. In this modification, in each of the current collecting tabs 13C and 14C, a plurality of strip-shaped portions are bound at one place, and each of the current collecting tabs 13C and 14C includes only one binding portion 18.

However, in this modification, each of the connection leads 20 does not sandwich the binding portion 18 between the extension portions 42A and 42B. In this modification, the binding portion 18 is joined to the surface of the extension portion 42A facing the opposite side of the extension portion 42B. That is, in each of the connection leads 20, a joint portion 55 with one of the current collector tabs 13C and 14C is formed on the surface of the extension portion 42A facing the opposite side of the extension portion 42B. Therefore, in each of the connection leads 20, the joint portion 55 is formed only on the extension portion 42A of the leg portion 32A. Further, in this modification, the binding portion 18 is joined to the extending portion 42A while being sandwiched between the backup leads 56. When welding is performed using the ultrasonic horn in the manufacturing of the battery 1, for example, the ultrasonic horn is brought into contact with the backup lead 56. At this time, the backup lead 56 prevents the binding portion 18 from being exposed, and protects the binding portion 18 of the current collecting tab (13C or 14C).

Further, in the fourth modification shown in FIG. 10, similarly to the second modification, in each of the current collecting tabs 13C and 14C, a plurality of strips are bundled at two places, and the current collecting tabs 13C and 14C are connected. Each includes two binding portions 18A and 18B. Then, the binding portions 18A and 18B are joined to the surface of the extension portion 42A facing the opposite side of the extension portion 42B. Therefore, as in the third modification, in each of the connection leads 20, the extension portion 42A is joined to the corresponding one of the current collecting tabs 13C and 14C on the surface facing the side opposite to the extension portion 42B. The portion 55 is formed. Therefore, in each of the connection leads 20, the joint portion 55 is formed only on the extension portion 42A of the leg portion 32A. Further, each of the binding portions 18A and 18B is joined to the extending portion 42A while being sandwiched between the backup leads 56. In one example of FIG. 10, the binding portion 18B is joined to the extending portion 42A at a position closer to the top plate portion 31 than the binding portion 18A.

Further, in the fifth modification shown in FIG. 11, the current collecting tabs 13C and 14C each include two binding portions 18A and 18B, as in the second modification and the like. In this modification, the binding portion 18A is joined to the surface of the extension portion 42A facing the opposite side of the extension portion 42B, and the binding portion is joined to the surface of the extension portion 42B facing the opposite side of the extension portion 42A. 18B is joined. Therefore, in each of the connection leads 20, the current collecting tabs are on the surface of the extension portion 42A facing the opposite side of the extension portion 42B and the surface of the extension portion 42B facing the side opposite to the extension portion 42A. A joint 55 with the corresponding one of 13C and 14C is formed. Therefore, in each of the connection leads 20, the joint portion 55 is formed on both the extension portion 42A of the leg portion 32A and the extension portion 42B of the leg portion 32B.

In this modified example, each of the connection leads 20 does not sandwich one of the binding portions 18A and 18B of the current collecting tabs 13C and 14C between the extending portions 42A and 42B. Further, the binding portion 18A is joined to the extension portion 42A while being sandwiched between the backup leads 56, and the binding portion 18B is joined to the extension portion 42B while being sandwiched between the backup leads 56. When welding is performed using the ultrasonic horn in the manufacturing of the battery 1, for example, the ultrasonic horn is brought into contact with one of the backup reed 56 that sandwiches the binding portion 18A and the backup lead 56 that sandwiches the binding portion 18B. .. Further, in an example of FIG. 11, the distance from the top plate portion 31 to the binding portion 18A is the same as or substantially the same as the distance from the top plate portion 31 to the binding portion 18B.

Further, in the sixth modification shown in FIG. 12, the current collecting tabs 13C and 14C each include two binding portions 18A and 18B, as in the fifth modification and the like. Then, the binding portion 18A is joined to the surface of the extension portion 42A facing the opposite side of the extension portion 42B, and the binding portion 18B is joined to the surface of the extension portion 42B facing the opposite side of the extension portion 42A. Will be done. Therefore, in each of the connection leads 20, the current collecting tabs are on the surface of the extension portion 42A facing the opposite side of the extension portion 42B and the surface of the extension portion 42B facing the side opposite to the extension portion 42A. A joint 55 with the corresponding one of 13C and 14C is formed. Further, each of the binding portions 18A and 18B is sandwiched between backup leads 56. However, in this modification, the binding portion 18B is joined to the connecting lead 20 at a position closer to the top plate portion 31 than the binding portion 18A.

Further, in the above-described embodiment or the like, in the leg portion 32A, the relay portion 43A2 is extended in a state of being inclined with respect to the extension portion 42A, and in the leg portion 32B, the relay portion 43B2 is inclined with respect to the extension portion 42B. It will be extended in the state of being, but it is not limited to this.

In the seventh modification shown in FIG. 13, in each of the connection leads 20, the relay portion 43A2 of the leg portion 32A and the relay portion 43B2 of the leg portion 32B are extended along the width direction of the top plate portion 31. Therefore, in the battery 1, the relay portions 43A2 and 43B2 of the connection leads 20 are extended along the vertical direction. In this modification, the bending angle of the relay portion 43A2 at the bending position 45A1 with respect to the relay portion 43A1 and the bending angle of the relay portion 43A2 at the bending position 45A2 with respect to the extending portion 42A are 90 degrees or approximately 90 degrees, respectively. It becomes a right angle. The bending angle of the relay portion 43B2 at the bending position 45B1 with respect to the relay portion 43B1 and the bending angle of the relay portion 43B2 at the bending position 45B2 with respect to the extension portion 42B are 90 degrees or approximately 90 degrees, respectively. ..

Further, in the present modification, in the leg portion 32A, the relay portion 43A2 extends from the bending position 45A1 to the bending position 45A2 toward the side where the leg portion 32B is located. Then, in the leg portion 32B, the relay portion 43B2 extends from the bending position 45B1 to the bending position 45B2 toward the side where the leg portion 32A is located. Also in this modification, the relay portion 43A2 forms a bent portion (first bent portion) that bends with respect to the relay portion 43A1 and the extended portion 42A, and the relay portion 43B2 forms the relay portion 43B1 and the extended portion 42B. A bent portion (second bent portion) that bends is formed. Further, in the present modification, as in the first embodiment or the like, each of the connection leads 20 sandwiches one of the binding portions 18 of the current collecting tabs 13C and 14C between the extending portions 42A and 42B. A joint portion 55 with one of the current collector tabs 13C and 14C is formed on both of the extension portions 42A and 42B.

Further, in the above-described embodiment or the like, in the leg portion 32A, the leg connection portion 41A is folded into the relay portion (first relay portion) between the top plate portion 31 (leg connection portion 41A) and the extension portion 42A. Two bending positions 45A1 and 45A2 are formed in addition to the bending positions, but the present invention is not limited to this. Similarly, in the above-described embodiment or the like, in the leg portion 32B, the relay portion (second relay portion) between the top plate portion 31 (leg connection portion 41B) and the extension portion 42B is connected to the leg connection portion 41B. Two bending positions 45B1 and 45B2 are formed in addition to the bending positions, but the present invention is not limited to this.

In the eighth modification shown in FIG. 14, the leg connecting portion 41A is used at the relay portion (first relay portion) between the top plate portion 31 (leg connecting portion 41A) and the extending portion 42A in the leg portion 32A. Only one bending position 45A1 is formed in addition to the bending position of. Then, in the leg portion 32B, the relay portion (second relay portion) between the top plate portion 31 (leg connection portion 41B) and the extension portion 42B has a bending position other than the bending position at the leg connection portion 41B. Only one 45B1 is formed. In this modification, the leg connection portion 41A and the extension portion 42A are relayed in the leg portion 32A only via the relay portion 43A1, and the leg connection portion 41B and the extension portion 42B are relayed in the leg portion 32B. , It is relayed only through the relay unit 43B1.

In this modification, the relay portion 43A1 is connected to the top plate portion 31 via the leg connecting portion 41A, and is connected to the extending portion 42A at the bending position 45A1. Then, the relay portion 43A1 bends with respect to the top plate portion 31 at the leg connecting portion 41A, and bends with respect to the extending portion 42A at the bending position 45A1. The relay portion (first bent portion) 43A1 bends at the bent position 45A1 with respect to the extending portion 42A toward the side away from the leg portion 32B. Further, the bending angle of the relay portion 43A1 at the leg connecting portion 41A with respect to the top plate portion 31 is an obtuse angle of 150 degrees or less. The bending angle of the relay portion 43A1 with respect to the extending portion 42A at the bending position 45A1 is an acute angle of 60 degrees or less. Since the relay portion 43A1 is formed as described above, the relay portion 43A1 is inclined with respect to the extension portion 42A so that the portion closer to the extension portion (first extension portion) 42A is closer to the leg portion 32B. do.

Further, the relay portion 43B1 is formed plane-symmetrically or substantially plane-symmetrically with respect to the relay portion 43A1 centering on the central surface of the connection lead 20 in the width direction of the top plate portion 31. The bent position 45B1 is arranged plane-symmetrically or substantially plane-symmetrically with respect to the bent position 45B1 with the central surface of the connecting lead 20 in the width direction of the top plate portion 31 as the center. Therefore, the relay portion (second bent portion) 43B1 bends at the bent position 45B1 with respect to the extending portion 42B toward the side away from the leg portion 32A. Then, the relay portion 43B1 is inclined with respect to the extension portion 42B so that the portion closer to the extension portion (second extension portion) 42B is closer to the leg portion 32A.

In the ninth modification shown in FIG. 15, in the leg portion 32A, the leg connecting portion 41A is connected to the relay portion (first relay portion) between the top plate portion 31 (leg connecting portion 41A) and the extension portion 42A. In addition to the bending positions of, three bending positions 45A1, 45A2, 45A3 are formed. Then, in the leg portion 32B, the relay portion (second relay portion) between the top plate portion 31 (leg connection portion 41B) and the extension portion 42B is folded three times in addition to the bending position at the leg connection portion 41B. Bending positions 45B1, 45B2, 45B3 are formed. In this modified example, the leg connecting portion 41A and the extending portion 42A are relayed in order from the side closer to the leg connecting portion 41A in the leg portion 32A via the relay portions 43A1, 43A2, 43A3, and the legs in the leg portion 32B. The connection portion 41B and the extension portion 42B are relayed in order from the side closer to the leg connection portion 41B via the relay portions 43B1, 43B2, 43B3.

In this modification, the relay portion 43A1 is connected to the top plate portion 31 via the leg connecting portion 41A, and is connected to the relay portion 43A2 at the bending position 45A1. Further, the relay portion 43A3 is connected to the relay portion 43A2 at the bending position 45A2, and is connected to the extension portion 42A at the bending position 45A3. The relay portion 43A2 extends along the thickness direction of the top plate portion 31. Then, the relay portion 43A1 bends with respect to the top plate portion 31 at the leg connecting portion 41A, and bends with respect to the relay portion 43A2 at the bending position 45A1. The relay portion 43A1 bends with respect to the relay portion 43A2 toward the side closer to the leg portion 32B at the bending position 45A1. The bending angle of the relay portion 43A1 at the leg connecting portion 41A with respect to the top plate portion 31 is an acute angle of 30 degrees or more. The bending angle of the relay portion 43A1 with respect to the relay portion 43A2 at the bending position 45A1 is an acute angle of 60 degrees or less.

Further, the relay portion 43A3 bends with respect to the relay portion 43A2 at the bending position 45A2, and bends with respect to the extension portion 42A at the bending position 45A3. The relay portion (first bent portion) 43A3 bends at the bending position 45A3 with respect to the extending portion 42A toward the side away from the leg portion 32B. The bending angle of the relay part 43A3 with respect to the relay part 43A2 at the bending position 45A2 and the bending angle of the relay part 43A3 with respect to the extending part 42A at the bending position 45A3 are larger than 0 degrees and more than 90 degrees. small. Since the relay portion 43A3 is formed as described above, the relay portion 43A3 is inclined with respect to the extension portion 42A so that the portion closer to the extension portion (first extension portion) 42A is closer to the leg portion 32B. do.

The relay section 43B1 is for the relay section 43A1, the relay section 43B2 is for the relay section 43A2, and the relay section 43B3 is for the relay section 43A3, centering on the central surface of the connection lead 20 in the width direction of the top plate section 31. Therefore, it is formed plane-symmetrically or substantially plane-symmetrically. Then, centering on the central surface of the connecting lead 20 in the width direction of the top plate portion 31, the bending position 45B1 is at the bending position 45A1, and the bending position 45B2 is at the bending position with respect to the bending position 45A2. The 45B3 is arranged plane-symmetrically or substantially plane-symmetrically with respect to the bending position 45A3. Therefore, the relay portion (second bent portion) 43B3 bends at the bent position 45B3 with respect to the extending portion 42B toward the side away from the leg portion 32A. Then, the relay portion 43B3 is inclined with respect to the extension portion 42B so that the portion closer to the extension portion (second extension portion) 42B is closer to the leg portion 32A.

Further, in a modified example, in each leg portion 32A of the connection lead 20, a leg connection is made to a relay portion (first relay portion) between the top plate portion 31 (leg connection portion 41A) and the extension portion 42A. Four or more bending positions (45A1, 45A2, ...) Are formed in addition to the bending position in the portion 41A. Then, in each of the leg portions 32B of the connection lead 20, the leg connection portion 41B is folded into the relay portion (second relay portion) between the top plate portion 31 (leg connection portion 41B) and the extension portion 42B. In addition to the bending positions, four or more bending positions (45B1, 45B2, ...) Are formed.

Further, in the above-described embodiment and the like, in each of the current collecting tabs 13C and 14C, the portions on both sides of the binding portion 18 in the width direction of the electrode group 2 are cut from the electrode group 2, but the present invention is limited to this. is not it. In the tenth modification shown in FIG. 16, in the production of the electrode group 2, after forming the binding portion 18 on each of the current collecting tabs 13C and 14C, the width direction of the electrode group 2 is formed on each of the current collecting tabs 13C and 14C. Only one side of the binding portion 18 is cut from the electrode group 2. Therefore, in each of the current collecting tabs 13C and 14C, the portion on the opposite side of the binding portion 18 in the width direction of the electrode group 2 is not cut from the electrode group 2. Therefore, in the electrode group 2 of the battery 1, a curved surface portion 17 is formed on one side of the current collecting tabs 13C and 14C with respect to the binding portion 18 in the width direction of the electrode group 2. Since it is not necessary to cut one of the curved surface portions 17 at each of the current collecting tabs 13C and 14C, the formation of the electrode group 2 becomes easy.

In this modification, as in the first embodiment or the like, each of the connection leads 20 has one of the binding portions (held portions) 18 of the current collecting tabs 13C and 14C attached to the extending portions 42A and 42B. Put it in between. Then, each of the current collecting tabs 13C and 14C is joined by the extension portions 42A and 42B to the corresponding one of the connection leads 20 in a state where the binding portion 18 is sandwiched between the extension portions 42A and 42B. Further, in the battery 1, in each of the current collecting tabs 13C and 14C, the curved surface portion 17 is located on the side where the corresponding top plate portion 31 of the connection lead 20 is located with respect to the binding portion (held portion) 18. Provided. That is, in each of the current collecting tabs 13C and 14C, the curved surface portion 17 is arranged on the side closer to the lid member 5 with respect to the binding portion 18. Further, in the internal cavity 8, the curved surfaces of the current collecting tabs 13C and 14C are the corresponding relay part (first relay part) 43A1 and the relay part (second relay part) 43B1 of the connection lead 20. Placed between.

Further, in the above-described embodiment and the like, the legs 32A and 32B are centered on the central surface of the connection lead 20 in the width direction of the top plate 31 except that the thin plate portion 50 is formed on the leg portion 32A. As a result, they are formed plane-symmetrically or substantially plane-symmetrically with respect to each other, but the present invention is not limited to this. In the eleventh modification shown in FIG. 17, the legs 32A and 32B are non-plane symmetric with respect to each other with the central surface of the connecting lead 20 in the width direction of the top plate 31 as the center. Therefore, in the above-described embodiment and the like, the central surface of the connecting lead 20 in the width direction of the top plate portion 31 is defined between the extending portions 42A and 42B, but in this modification, the top plate portion 31 The central surface of the connecting lead 20 in the width direction is not defined between the extending portions 42A and 42B.

In this modification, each of the current collecting tabs 13C and 14C is joined to the corresponding one of the connection leads 20 on the surface of the extension portion 42A facing the opposite side of the extension portion 42B. At this time, each of the current collecting tabs 13C and 14C is connected to the extending portion 42A with the binding portion 18 sandwiched between the backup leads 56. By using the connection lead 20 of this modification, for example, when the binding portion 18 is formed in the current collecting tab (13C or 14C) with the binding portion 18 deviated from the center position of the electrode group 2 in the thickness direction of the electrode group 2. In addition, the current collecting tab (13C or 14C) can be easily connected to the connection lead 20.

Further, in the twelfth modification shown in FIG. 18, in the leg portion 32B which is one of the leg portions 32A and 32B, the relay portion 43B1 between the top plate portion 31 (leg connection portion 41B) and the extension portion 42B is formed. , No bending position is formed other than the bending position at the leg connecting portion 41B. Then, the leg portion 32B extends straight or substantially straight along the thickness direction of the top plate portion 31 from the leg connecting portion 41B to the protruding end. That is, the leg portion 32B extends straight or substantially straight over the entire relay portion 43B1 and the extension portion 42B without bending. However, even in this modified example, in the leg portion 32A, which is not straight among the leg portions 32A and 32B, the leg is connected to the relay portion between the top plate portion 31 (leg connection portion 41A) and the extension portion 42A. One or more bending positions (45A1, 45A2, etc.) are formed in addition to the bending position in the portion 41B.

In this modification as well as in the eleventh modification, the legs 32A and 32B are non-plane symmetric with respect to each other with the central surface of the connecting lead 20 in the width direction of the top plate 31 as the center. Therefore, the central surface of the connecting lead 20 in the width direction of the top plate portion 31 is not defined between the extending portions 42A and 42B. By using the connection lead 20 of this modification, for example, in the current collecting tab (13C or 14C), the binding portion is formed from the center position of the electrode group 2 in the thickness direction of the electrode group 2 in the same manner as in the eleventh modification. When the 18 is formed so as to be displaced, the current collecting tab (13C or 14C) can be easily connected to the connection lead 20. Further, in the present modification, since the bending position is not formed on one leg portion 32B other than the bending position at the leg connecting portion 41B, the connection lead 20 can be easily formed.

In any of the above-described modifications, as in the first embodiment or the like, the connection lead 20 has the top plate portion 31 and the top plate portion 31 on the same side with respect to each other in the thickness direction of the top plate portion 31. A pair of legs 32A and 32B that bend with respect to the leg portion 32A and 32B are provided. The connection position of the leg connection portion 41A of the leg portion 32A to the top plate portion 31 is in the width direction of the top plate portion 31 with respect to the connection position of the leg connection portion 41B of the leg portion 32B to the top plate portion 31. Distance (first distance) L1 away. And the distance L1 has a certain size. Therefore, as in the first embodiment and the like, in any of the modified examples, in the portion where the legs 32A and 32B are connected and their vicinity, that is, in the top plate constituent portion 35, in the width direction of the top plate portion 31. The dimensions can be increased, and the cross-sectional area of the top plate portion 31 in the top plate constituent portion 35 can be increased. Therefore, in any of the modified examples, by ensuring a large cross-sectional area of the top plate portion 31 in the top plate constituent portion 35, the electric resistance of the connection lead 20 is ensured low, and the current collecting tabs 13C and 14C are respectively. Low electrical resistance is ensured in the current path between the electrode terminal 21 and the corresponding one.

Further, in any of the above-described modifications, the leg portion 32A is provided with the extension portion 42A on the side opposite to the top plate portion 31 with respect to the leg connection portion 41A, and the leg portion 32B is provided with the leg connection portion. An extension portion 42B is provided on the side opposite to the top plate portion 31 with respect to 41B. The distance between the extending portions 42A and 42B in the width direction of the top plate portion 31 is a distance (second distance) L2 smaller than the distance (first distance) L1. The distance L2 is, for example, very small or zero. Since the distance L2 between the extending portions 42A and 42B becomes small, the rigidity of the connecting lead 20 is ensured high in each of the modified examples as in the first embodiment and the like, and the connection lead 20 is secured in the battery 1. Resistance to each impact is improved.

Further, in the above-described embodiments and modifications, the thin plate portion 50 is not formed on any of the legs 32A and 32B ( extended portions 42A and 42B), or the legs 32A and 32B ( extended portions 42A, 42B). It is formed on one side of 42B). However, the thin plate portion 50 may be formed on both the extending portions 42A and 42B. In this case, in each of the extending portions 42A and 42B, a joint portion 55 with the corresponding binding portion 18 of the current collecting tabs 13C and 14C is formed on the thin plate portion 50.

When the thin plate portion 50 is formed in the extension portion 42A, a recess in the thin plate portion 50 with respect to a portion other than the thin plate portion 50, that is, a step 51 is formed on a surface facing the side where the extension portion 42B is located. It may be formed on the surface facing the side opposite to the extension portion 42B. However, when the binding portion 18 is joined to the extending portion 42A with the binding portion 18 sandwiched between the extending portions 42A and 42B, the above-mentioned recess is formed on the side where the extending portion 42B is located. It is preferably formed on the facing surface. As a result, the thickness of the binding portion 18 is absorbed, and the distance L2 between the extending portions 42A and 42B can be further reduced. On the other hand, when the binding portion 18 is joined to the extension portion 42A on the surface facing the side opposite to the extension portion 42B, the above-mentioned recess is formed on the surface facing the side opposite to the extension portion 42B. Is preferable. Therefore, it is preferable that the dent formed by the thin plate portion 50 is formed on the surface of the extending portion 42A facing the side where the binding portion 18 abuts. The case where the thin plate portion 50 is formed on the extension portion 42B is the same as the case where the thin plate portion 50 is formed on the extension portion 42A.

Both the positive electrode side connecting lead between the positive electrode current collecting tab 13C and the positive electrode terminal and the negative electrode side connecting lead between the negative electrode current collecting tab 14C and the negative electrode terminal are described in the above-described embodiments and modifications. It is not necessary to have the same configuration as any of the connection leads 20. That is, at least one of the positive electrode side connecting lead and the negative electrode side connecting lead may have the same configuration as the connecting lead 20 of any one of the above-described embodiments and modifications.

According to at least one of these embodiments or embodiments, in the connecting lead, the leg connecting portions of the pair of legs are located on the top plate portion at a position first distance from each other in the width direction of the top plate portion. Be connected. Then, in each of the pair of leg portions, an extension portion is provided at a position opposite to the top plate portion with respect to the leg connection portion, and the first extension portion between the pair of leg portions is provided. It becomes a second distance smaller than the distance of. As a result, it is possible to provide a connection lead in which high rigidity is ensured and low electrical resistance is ensured.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

Claims (10)

1. A connection lead that connects the current collecting tab of the electrode group and the electrode terminal in the battery.
   Top plate and
   A pair of legs that bend to the same side with respect to each other in the thickness direction of the top plate, and
   Equipped with
   The first leg, which is one of the pair of legs,
   The first leg connection portion connected to the top plate portion and
   A first extension portion located away from the top plate portion with respect to the first leg connection portion, and a first extension portion.
   With
   The second leg, which is the other of the pair of legs,
   With respect to the width direction of the top plate portion, a second leg connecting portion connected to the top plate portion at a position separated from the first leg connecting portion by a first distance, and
   It is located away from the top plate portion with respect to the second leg connection portion, and is located between the first leg portion and the first extension portion in the width direction of the top plate portion. With a second extension having a second distance smaller than the first distance,
   With connection leads.
2. The first leg portion is provided between the first leg connection portion and the first extension portion, and is provided with respect to the first extension portion toward a side away from the second leg portion. It has a first bend that bends or
   The second leg portion is provided between the second leg connecting portion and the second extension portion, and is provided with respect to the second extension portion toward a side away from the first leg portion. Provide a second bend that bends
   The connection lead of claim 1, which is at least one of the above.
3. The first bent portion is inclined with respect to the first extended portion so that the portion closer to the first extended portion is closer to the second leg portion.
   The second bent portion is inclined with respect to the second extended portion so that the portion closer to the second extended portion is closer to the first leg portion.
   The connection lead of claim 2, which is at least one of the above.
4. The first leg portion is provided on the side opposite to the top plate portion with respect to the first extension portion, and forms a protruding end of the first leg portion from the top plate portion. Is provided with a first end plate portion that bends with respect to the first extension portion on the side away from the second leg portion, or
   The second leg portion is provided on the side opposite to the top plate portion with respect to the second extension portion, and forms a protruding end of the second leg portion from the top plate portion. Is provided with a second end plate portion that bends with respect to the second extension portion on the side away from the first leg portion.
   The connection lead according to any one of claims 1 to 3, which is at least one of the above.
5. The connection lead according to any one of claims 1 to 4 and
   An outer container provided with a bottom wall and a peripheral wall, and an internal cavity in which the connecting lead is arranged is defined by the bottom wall and the peripheral wall.
   A current collecting tab provided with a positive electrode and a negative electrode, which is joined to the connection lead at least one of the first extension portion of the first leg portion and the second extension portion of the second leg portion. Electrode group to be provided and
   A lid member that is attached to the peripheral wall at an end opposite to the bottom wall and closes the opening of the internal cavity of the outer container.
   An electrode terminal attached to the outer surface of the lid member and connected to the top plate portion of the connection lead,
   Batteries equipped with.
6. In the connection lead, a joint portion with the current collecting tab is formed at least in the first extension portion of the first leg portion.
   The thickness of the first leg portion at the joint portion of the first extension portion is the thickness of the first leg portion between the top plate portion and the joint portion of the first extension portion. Small compared to the thickness,
   The battery of claim 5.
7. In the connection lead, a joint portion with the current collecting tab is formed at least in the first extension portion of the first leg portion.
   The width of the first leg portion at the joint portion of the first extension portion is the width of the first leg portion between the top plate portion and the joint portion of the first extension portion. Larger than the width,
   The battery of claim 5 or 6.
8. In the connection lead, a joint portion with the current collecting tab is formed on both the first extension portion of the first leg portion and the second extension portion of the second leg portion.
   The current collecting tab is joined to the joint portion in a state of being sandwiched between the first extension portion of the first leg portion and the second extension portion of the second leg portion. Equipped with a holding part
   The battery according to any one of claims 5 to 7.
9. In the electrode group, the positive electrode and the negative electrode are wound around the winding shaft.
   The first leg portion includes a first relay portion that relays between the first leg connection portion and the first extension portion.
   The second leg portion includes a second relay portion that relays between the second leg connection portion and the second extension portion.
   The current collecting tab is provided on the side where the top plate portion of the connection lead is located with respect to the sandwiched portion, and the first relay portion and the second relay portion of the first leg portion in the internal cavity. A curved surface portion arranged between the leg portion and the second relay portion of the leg portion is provided.
   The battery of claim 8.
10. The current collecting tab includes a positive electrode current collecting tab protruding from the electrode group and a negative electrode current collecting tab protruding from the electrode group to the side opposite to the side on which the positive electrode current collecting tab protrudes.
    The electrode terminal includes a positive electrode terminal and a negative electrode terminal.
    The connecting lead is at least one of connecting between the positive electrode current collecting tab and the positive electrode terminal, and the connecting lead connecting between the negative electrode current collecting tab and the negative electrode terminal.
    The battery according to any one of claims 5 to 9.

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