CN219040550U - Connection lead and battery - Google Patents

Abstract

According to an embodiment, there is provided a connection lead that connects between a collector tab of an electrode group and an electrode terminal in a battery. The connecting lead includes a top plate portion and a pair of leg portions, and the pair of leg portions are bent with respect to the top plate portion on the same side as each other in the thickness direction of the top plate portion. In the connection lead, the leg connection portions of the pair of leg portions are connected to the top plate portion at positions separated from each other by a first distance in the width direction of the top plate portion. The pair of leg portions are each provided with an extension portion at a position distant from the leg connecting portion toward the opposite side from the top plate portion, and a second distance smaller than the first distance is provided between the extension portions of the pair of leg portions.

Description

Connection lead and battery

Technical Field

Embodiments of the present utility model relate to connecting leads and batteries.

Background

In recent years, secondary batteries such as lithium ion secondary batteries are mounted on electric vehicles, hybrid vehicles, electric motorcycles, forklift trucks, and the like. Such a battery such as a secondary battery is required to have high output and long life, and is required to have high impact resistance against external force and vibration.

As a battery such as a secondary battery, there is a case where an electrode group including a positive electrode and a negative electrode is housed in an internal cavity of an exterior container. In this battery, the outer container has a bottom wall and a peripheral wall, and a lid member is attached to an end portion of the peripheral wall of the outer container on the opposite side of the bottom wall. The inner cavity of the outer container is closed by the lid member. In addition, in the battery, an electrode terminal is attached to the outer surface of the lid member, and the collector tab protrudes from the electrode group in the internal cavity. The current collecting tab is electrically connected to the electrode terminal via a connection lead (lead).

In such a battery, it is required to ensure high rigidity of the connection lead. In addition, the connection leads form a current path between the electrode group and the electrode terminal. Therefore, it is required to ensure that the resistance of the connection leads is low.

Prior art literature

Patent literature

Patent document 1: japanese patent application laid-open No. 2011-71109

Disclosure of Invention

First, the technical problem to be solved

The present utility model provides a connection lead capable of ensuring high rigidity and low resistance, and a battery provided with the connection lead.

(II) technical scheme

According to an embodiment, there is provided a connection lead for connecting a collector tab of an electrode group and an electrode terminal in a battery. The connecting lead includes a top plate portion and a pair of leg portions, and the pair of leg portions are bent with respect to the top plate portion on the same side as each other in the thickness direction of the top plate portion. One of the pair of legs, namely, the first leg portion 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 extending portion is located at a position away from the first leg connecting portion on the opposite side of the top plate portion. The second leg portion, which is the other leg portion of the pair of leg portions, includes a second leg connecting portion and a second extending portion, and the second leg connecting portion is connected to the top plate portion at a position separated from the first leg connecting portion by a first distance in the width direction of the top plate portion. The second extending portion is located away from the second leg connecting portion on the opposite side of the top plate portion, and has a second distance smaller than the first distance between the first extending portion of the first leg portion and the top plate portion in the width direction.

According to an embodiment, a battery includes: the connecting lead, the outer case, the electrode group, the lid member, and the electrode terminal. The outer container has a bottom wall and a peripheral wall defining an internal cavity in which the connecting leads are disposed. The electrode group includes a positive electrode and a negative electrode, and a collector tab connected to a connecting wire at least one of a first extension portion of the first leg portion and a second extension portion of the second leg portion. The lid member is attached to the peripheral wall at an end portion on the opposite side of the bottom wall, and closes the opening of the internal cavity of the outer container. The electrode terminal is mounted on the outer surface of the cover member and connected to the top plate portion of the connection lead.

Drawings

Fig. 1 is a perspective view schematically showing a battery according to a first embodiment.

Fig. 2 is a perspective view schematically showing the battery according to the first embodiment in a state of being disassembled by components.

Fig. 3 is a schematic diagram illustrating an example of a method for manufacturing an electrode group of a battery according to the first embodiment.

Fig. 4 is a perspective view showing the structure of the connection lead according to the first embodiment.

Fig. 5 is a cross-sectional view schematically showing a connection lead and its vicinity in the battery according to the first embodiment.

Fig. 6 is a schematic diagram illustrating an example of a method for manufacturing a connection lead according to the first embodiment.

Fig. 7 is a perspective view showing a structure of a connection lead according to a first modification.

Fig. 8 is a cross-sectional view schematically showing a joint portion between a connecting lead and a current collector tab and the vicinity thereof in the second modification.

Fig. 9 is a cross-sectional view schematically showing a joint portion between a connecting lead and a current collecting tab and the vicinity thereof according to a third modification

Fig. 10 is a cross-sectional view schematically showing a joint portion between a connecting lead and a current collector tab and the vicinity thereof in a fourth modification.

Fig. 11 is a cross-sectional view schematically showing a joint portion between a connection lead and a current collector tab and the vicinity thereof in a fifth modification.

Fig. 12 is a cross-sectional view schematically showing a joint portion between a connecting lead and a current collector tab and the vicinity thereof in a sixth modification.

Fig. 13 is a cross-sectional view schematically showing a joint portion between a connecting lead and a current collector tab and the vicinity thereof in the seventh modification.

Fig. 14 is a cross-sectional view schematically showing a joint portion between a connecting lead and a current collector tab and the vicinity thereof in the eighth modification.

Fig. 15 is a cross-sectional view schematically showing a joint portion between a connecting lead and a current collector tab and the vicinity thereof in a ninth modification.

Fig. 16 is a cross-sectional view schematically showing a joint portion between a connecting lead and a current collector tab and the vicinity thereof according to a tenth modification.

Fig. 17 is a cross-sectional view schematically showing a joint portion between a connection lead and a current collector tab and the vicinity thereof in the eleventh modification.

Fig. 18 is a cross-sectional view schematically showing a joint portion between a connecting lead and a current collector tab and the vicinity thereof according to a twelfth modification.

Detailed Description

The embodiments are described below with reference to the drawings.

(first embodiment)

Fig. 1 and 2 show a battery 1 according to a first embodiment. As shown in fig. 1 and 2, the battery 1 includes an electrode group 2, an outer container 3, and a lid member 5. The outer container 3 and the lid member 6 are each formed of a metal such as aluminum, aluminum alloy, iron, copper, or stainless steel. Here, the battery 1 is defined as follows: a longitudinal direction (a direction indicated by an arrow X1 and an arrow X2), a transverse direction (a direction indicated by an arrow Y1 and an arrow Y2) intersecting the longitudinal direction (vertical or substantially vertical), and a height direction (a direction indicated by an arrow Z1 and an arrow Z2) intersecting both the longitudinal direction and the transverse direction (vertical or substantially vertical). The battery 1 and the outer case 3 are smaller in both the longitudinal direction and the height direction than in the lateral direction.

The outer container 3 includes a bottom wall 6 and a peripheral wall 7. The internal cavity 8 housing the electrode assembly 2 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, 12. A pair of side walls 11 are opposed across the inner cavity 8 in the lateral direction. A pair of side walls 12 are opposed longitudinally across the interior cavity 8. The side walls 11 are respectively provided extending continuously in the longitudinal direction between the side walls 12. The side walls 12 are respectively provided extending continuously in the lateral direction between the side walls 11. The cover member 5 is attached to the peripheral wall 7 at an end portion on the opposite side of the bottom wall 6. Thus, the lid member 5 closes the opening of the internal cavity 8 of the outer container 3. The lid member 5 and the bottom wall 6 are opposed to each other in the height direction across the internal cavity 8.

Fig. 3 is a diagram illustrating an example of a method for manufacturing 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, a separator 15 is interposed between the positive electrode 13 and the negative electrode 14. The separator 15 is made of an electrically insulating material, and electrically insulates the positive electrode 13 from the negative electrode 14.

The positive electrode 13 includes: a positive electrode collector 13A such as a positive electrode collector foil, and a positive electrode active material-containing layer 13B supported on the surface of the positive electrode collector 13A. The positive electrode current collector 13A is not limited to this, and may be, for example, aluminum foil, aluminum alloy foil, or the like, and has a thickness of about 10 μm to 20 μm. The positive electrode active material-containing layer 13B contains a positive electrode active material, and may optionally contain a binder and a conductive agent. The positive electrode active material is not limited to this, and examples thereof include oxides, sulfides, and polymers capable of absorbing and releasing lithium ions. The positive electrode collector 13A includes a positive electrode collector tab 13C as a portion on which 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 this, and may be, for example, aluminum foil, aluminum alloy foil, 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 absorbing and desorbing lithium ions. The negative electrode current collector 14A includes a negative electrode current collector sheet 14C as a portion on which 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 wound around the winding axis B with the separator 15 interposed between the positive electrode active material containing layer 13B and the negative electrode active material containing layer 14B. In the electrode group 2, the positive electrode 13, the separator 15, the negative electrode 14, and the separator 15 are wound in a state of being overlapped in this order. In the electrode group 2, the positive electrode collector tab 13C protrudes from the negative electrode 14 and the separator 15. The negative electrode collector tab 14C protrudes from the positive electrode 13 and the separator 15 to the opposite side of the protruding direction of the positive electrode collector tab 13C. In the present embodiment, the positive electrode collector tab 13C protrudes to one side along the axial direction of the winding axis B (arrow Y3 and arrow Y4), and the negative electrode collector tab 14C protrudes to the opposite side of the positive electrode collector tab 13C in the direction along the winding axis B.

For electrode group 2, provision is made for: a width direction (directions indicated by arrows Z3 and Z4) intersecting the axial direction (the protruding direction of the current collecting tabs 13C, 14C) (vertical or substantially vertical), and a thickness direction (directions indicated by arrows X3 and X4) intersecting both the axial direction and the width direction. The electrode group 2 has a smaller dimension in the thickness direction than in the axial direction and a smaller dimension in the width direction. Thus, the electrode group 2 is formed in a flat shape. The electrode group 2 of one example of fig. 2 and the like has a larger dimension in the axial direction than in the width direction.

When the electrode group 2 is formed by winding around the winding axis B as described above, for example, the curved surface portions 17 are formed in the positive electrode collector tab 13C and the negative electrode collector tab 14C, respectively, in a state in the manufacturing process of the electrode group 2 of fig. 3 and the like. The current collecting tabs 13C and 14C are each formed with a curved surface portion 17 at both ends thereof in the width direction of the electrode group 2.

In the electrode group 2 of the example of fig. 2 and the like, the positive electrode collector tab 13C and the negative electrode collector tab 14C are each provided with a bundling portion 18 bundling a plurality of belt-shaped portions. In the present embodiment, the current collecting tabs 13C and 14C are each formed with a bundling portion 18 at the central portion in the width direction of the electrode group 2. The bundling section 18 is formed by, for example, starting from the state of fig. 3 or the like, pressing the central portions of the current collecting tabs 13C, 14C in the width direction of the electrode group 2 inward in the thickness direction of the electrode group 2, thereby forming the bundling section 18. Since the bundle portions 18 are formed as described above, the dimension of each bundle portion 18 in the thickness direction of the electrode group 2 is smaller than that of the other parts than the bundle portion 18 of the electrode group 2. In the electrode group 2 of the example of fig. 2 and the like, only 1 bundling section 18 is formed in each of the collector tabs 13C and 14C, and a plurality of belt-shaped sections are bundled at one position of the bundling section 18 in each of the collector tabs 13C and 14C.

In the production of the electrode group 2 of the example of fig. 2 and the like, after the bundling sections 18 are formed in the current collecting tabs 13C and 14C, the current collecting tabs 13C and 14C are cut from the electrode group 2 at the positions on both sides of the bundling section 18 in the width direction of the electrode group 2. Therefore, in the state of fig. 3 or the like, the curved surface portions 17 and the like formed in the current collecting tabs 13C, 14C, respectively, are cut off from the electrode group 2.

In an example of fig. 2 and the like, the electrode group 2 is disposed in the internal cavity 8 in a state where the winding axis B (axial direction) is parallel or substantially parallel to the lateral direction of the battery 1. The electrode group 2 is disposed in the 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 longitudinal direction of the battery 1. In the internal cavity 8 of the outer container 3, the bundling portion 18 of the positive electrode collector tab 13C protrudes to one side in the lateral direction with respect to the negative electrode 14 and the separator 15. The negative electrode collector tab 14C protrudes in the lateral direction with respect to the positive electrode 13 and the separator 15 to the side opposite to the side where the positive electrode collector tab 13C protrudes.

In addition, 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 stacked structure in which a plurality of positive electrodes and a plurality of negative electrodes are alternately stacked, and a separator is provided between the positive electrodes and the negative electrodes. At this time, too: in the electrode group 2, the positive electrode collector tab protrudes with respect to the negative electrode and the separator, and the negative electrode collector tab protrudes with respect to the positive electrode and the separator to the opposite side to the side where the positive electrode collector tab protrudes. In addition, for the electrode group 2, there is defined: a width direction intersecting (perpendicular or substantially perpendicular to) the protruding direction of the collector sheet, and a thickness direction intersecting (perpendicular or substantially perpendicular to) both the protruding direction and the width direction of the collector sheet. In addition, the electrode group 2 has a smaller dimension in the thickness direction than the dimension in the protruding direction and the dimension in the width direction of the current collector sheet.

In this example, too: the positive electrode collector sheet and the negative electrode collector sheet each have a bundling section 18 bundling a plurality of belt-shaped sections. Each collector sheet has a bundling portion 18 formed at least in the center in the width direction of the electrode group 2. In this example, too, the following applies: the positive electrode collector sheet protrudes to one side in the lateral direction of the battery 1 (the outer case 3) with respect to the negative electrode. In the electrode group 2, the negative electrode collector tab protrudes toward the side opposite to the side where the positive electrode collector tab protrudes with respect to the positive electrode in the lateral direction of the battery 1. In this example, too, the following applies: the electrode group 2 is disposed in the 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 longitudinal direction of the battery 1.

In the internal cavity 8, an electrolyte (not shown) is held (impregnated) in the electrode group 2. The electrolyte may be a nonaqueous electrolyte obtained by dissolving an electrolyte in an organic solvent, or may be an aqueous electrolyte such as an aqueous solution. Instead of the electrolyte solution, a gel 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 in place of the separator 15. At this time, the positive electrode 13 is electrically insulated from the negative electrode 14 by the solid electrolyte.

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

A pair of connection leads 20 are disposed in the inner cavity 8 of the outer container 3. The positive electrode collector tab 13C of the electrode group 2 is electrically connected to the positive electrode terminal, which is the corresponding one of the electrode terminals 21, via the positive electrode-side connection lead (positive electrode lead), which is the corresponding one of the connection leads (leads) 20. The negative electrode collector tab 14C of the electrode group 2 is electrically connected to a negative electrode terminal, which is a corresponding one of the electrode terminals 21, via a negative electrode-side connection lead (negative electrode lead), which is a corresponding one of the connection leads 20. The connection leads 20 are each formed of a conductive material such as metal. Examples of the conductive material forming the connection lead 20 include aluminum, stainless steel, copper, iron, and the like.

In addition, a pair of insulating protectors 23 and electrode holders 25 are disposed in the internal cavity 8 of the outer container 3. The insulating protectors 23 are each formed of a material having electrical insulation. One of the connection leads 20, that is, the positive electrode-side connection lead, and the positive electrode collector tab 13C are electrically insulated from the outer container 3 by a corresponding one of the insulating protectors 23, respectively, to prevent contact with the outer container 3. The negative electrode side connection lead, which is one of the connection leads 20, and the negative electrode collector tab 14C are electrically insulated from the outer container 3 by a corresponding one of the insulating protectors 23, respectively, to prevent contact with the outer container 3.

The electrode pressing member 25 is disposed between the electrode group 2 and the cover member 5 in the height direction of the battery 1. The electrode pressing member (internal insulating member) 25 is formed of a material having electrical insulation. The positive electrode collector tab 13C, the negative electrode collector tab 14C, and the pair of connection leads 20 are prevented from contacting the lid member 5 by the electrode pressing member 25, and are electrically insulated from the lid member 5.

In the example of fig. 1 and 2, a gas release valve 26 and a filling port 27 are formed in the cover member 5. A sealing plate 28 for sealing the liquid inlet 27 is welded to the outer surface of the lid member 5. The battery 1 may not be provided with the gas release valve 26, the liquid inlet 27, and the like.

Fig. 4 shows the structure of the connection lead 20, and fig. 5 shows the connection lead 20 and the vicinity thereof in the battery 1. Fig. 5 shows a connection state of the connection lead 20 and the current collector tab (corresponding one of the current collector tabs 13C and 14C). As shown in fig. 4 and 5, the connecting lead 20 includes a top plate 31 and a pair of legs 32A and 32B. The top plate 31 has extension ends E1 and E2, and the top plate 31 extends in the extension direction (directions indicated by arrows Y5 and Y6) from the extension end E1 to the extension end E2. The top plate 31 defines a width direction (directions indicated by arrows X5 and X6) intersecting (perpendicular or substantially perpendicular to) the extending direction (longitudinal direction), and a thickness direction (directions indicated by arrows Z5 and Z6) intersecting both the extending direction (longitudinal direction) and the width direction.

The top plate 31 is formed of top plate constituting portions 33 and 35. In the top plate portion 31, a top plate constituting portion (first top plate constituting portion) 33 forms an extended end E1. The top plate constituent part (second top plate constituent part) 35 is adjacent to the top plate constituent part 33 on the side where the extension end E2 is located. In the top plate portion 31, the top plate constituting portion 35 forms an extended end E2. The dimension (width) of the top plate portion 31 in the width direction at the top plate constituting portion 33 is larger than the dimension (width) of the top plate portion 31 in the width direction at the top plate constituting portion 35. The top plate 31 is formed to be plane-symmetrical or substantially plane-symmetrical about a central plane in the width direction. Further, a through hole 36 is formed in the top plate constituent portion 33, and the through hole 36 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 constituting 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 constituting portion 35 of the top plate portion 31. The top plate constituent unit 35 has a leg connecting portion 41A of the leg 32A connected to an edge of one side in the width direction of the top plate unit 31, and a leg connecting portion 41B of the leg 32B connected to an edge of the opposite side to the connection position of the leg connecting portion 41A in the width direction of the top plate unit 31. Therefore, the leg connecting portions 41A, 41B are connected to the top plate 31 at positions apart from each other in the width direction of the top plate 31. The connection position of the leg connection portion 41A and the top plate portion 31 is separated from the connection position of the leg connection portion 41B and the top plate portion 31 by a distance (first distance) L1 in the width direction of the top plate portion 31.

The leg portion 32A is bent with respect to the top plate 31 with the leg connecting portion 41A as a bending position. The leg portion 32A is bent toward one side in the thickness direction of the top plate portion 31 with respect to the top plate portion 31. The leg portion 32B is bent with respect to the top plate 31 with the leg connecting portion 41B as a bending position. The leg portion 32B is bent with respect to the top plate portion 31 toward the side where the leg portion 32A is bent in the thickness direction of the top plate portion 31. Accordingly, the leg portions 32A, 32B are bent with respect to the top plate 31 toward the same side as each other in the thickness direction of the top plate 31. The legs 32A and 32B protrude from the top plate 31 to the same side as each other in the thickness direction of the top plate 31.

Since the pair of legs 32A, 32B are formed as described above, the connecting lead 20 is formed in a two-strand shape. The bending lines formed in the leg connecting portions 41A and 41B extend along the extending direction (longitudinal direction) of the top plate 31. The bending lines formed in the leg connecting portions 41A and 41B intersect (are perpendicular or substantially perpendicular) both in the width direction of the top plate 31 and in the thickness direction of the top plate 31. The width direction (plate width direction) of each leg portion 32A, 32B coincides with or substantially coincides with the extending direction (longitudinal direction) of the top plate portion 31. The width direction of each leg 32A, 32B intersects (is perpendicular or substantially perpendicular to) both the width direction of the top plate 31 and the thickness direction of the top plate 31.

The leg portion (first leg portion) 32A includes an extension portion (first extension portion) 42A, and the extension portion (first extension portion) 42A is located at a position away from the leg connecting portion 41A on the opposite side of the top plate portion 31. The extension portion 42A is provided at a position farther from the top plate 31 than the foot connecting portion 41A. The leg portion (second leg portion) 32B includes an extension portion (second extension portion) 42B, and the extension portion (second extension portion) 42B is located away from the leg connecting portion 41B on the opposite side of the top plate portion 31. The extension portion 42B is provided at a position farther from the top plate 31 than the foot connecting portion 41B. The extension portions 42A and 42B extend along the thickness direction of the top plate 31, and the extension directions (longitudinal directions) of the extension portions 42A and 42B are identical or substantially identical to the thickness direction of the top plate 31. The thickness direction (plate thickness direction) of each of the extension portions 42A, 42B is identical or substantially identical to 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. In the width direction of the top plate portion 31, a distance (second distance) L2 is provided between the extension portion (second extension portion) 42B and the extension portion (first extension portion) 42A. The distance L2 may be less than the distance L1, and the distance L2 may be zero. When the distance L2 is zero, the extension portion 42B abuts against the extension portion 42A from one side in the width direction of the top plate portion 31. Since the distances L1 and L2 are the above-described magnitudes, the leg portions 32A and 32B are closer to each other between the extension portions 42A and 42B than between the leg connecting portions 41A and 41B.

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

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

The relay portion 43A2 is connected to the relay portion 43A1 at the bending position 45A1, and is connected to the extension portion 42A at the bending position 45 A2. In the present embodiment, the relay portion 43A2 forms a bent portion (first bent portion) that is bent with respect to the relay portion 43A1 and the extension portion 42A. The relay portion 43A2 is bent toward the leg portion 32B with respect to the relay portion 43A1 at the bending position 45 A1. The intermediate portion 43A2 is bent at the bending position 45A2 toward the side away from the leg portion 32B with respect to the extension portion 42A. The bending angle of the intermediate portion 43A2 at the bending position 45A1 with respect to the intermediate portion 43A1 and the bending angle of the intermediate portion 43A2 at the bending position 45A2 with respect to the extension portion 42A are respectively greater than 0 degrees and less than 90 degrees. Since the relay portion 43A2 is formed as described above, the relay portion 43A2 is inclined with respect to the extension portion 42A in a state where the portion closer to the extension portion (first extension portion) 42A is closer to the leg portion 32B.

The relay portion 43B2 is connected to the relay portion 43B1 at the bending position 45B1, and is connected to the extension portion 42B at the bending position 45B 2. In the present embodiment, the relay portion 43B2 forms a bent portion (second bent portion) that is bent with respect to the relay portion 43B1 and the extension portion 42B. The relay portion 43B2 is bent toward the leg portion 32A with respect to the relay portion 43B1 at the bending position 45B 1. The intermediate portion 43B2 is bent at the bending position 45B2 toward the side away from the leg portion 32A with respect to the extension portion 42B. The bending angle of the intermediate portion 43B2 at the bending position 45B1 with respect to the intermediate portion 43B1 and the bending angle of the intermediate portion 43B2 at the bending position 45B2 with respect to the extension portion 42B are respectively greater than 0 degrees and less than 90 degrees. Since the relay portion 43B2 is formed as described above, the relay portion 43B2 is inclined with respect to the extension portion 42B in a state where the closer to the extension portion (second extension portion) 42B is to the foot portion 32A.

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

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

The end plate 47A is connected to the extension portion 42A at a bending position 48A. The end plate 47A is bent at the bending position 48A toward the side away from the leg portion 32B with respect to the extension portion 42A. Accordingly, the end plate portion 47A is inclined with respect to the extension portion 42A in a state of being further away from the leg portion 32B as the portion closer to the protruding end of the leg portion 32A. The end plate 47B is connected to the extension portion 42B at a bending position 48B. The end plate 47B is bent at the bending position 48B toward the side away from the leg portion 32A with respect to the extension portion 42B. Accordingly, the end plate portion 47B is inclined with respect to the extension portion 42B in a state of being further away from the leg portion 32A as the portion closer to the protruding end of the leg portion 32B. Further, the bending angle of the end plate portion 47A at the bending position 48A with respect to the extension portion 42A and the bending angle of the end plate portion 47B at the bending position 48B with respect to the extension portion 42B are respectively greater than 0 degrees and less than 90 degrees. The closer the end plate portions 47A, 47B are to the extension portions 42A, 42B, the smaller the mutual distance in the width direction of the top plate portion 31 is.

In the present embodiment, the thin plate portion 50 is formed on the leg portion 32A from the extension portion 42A to the protruding end. That is, the thin plate portion 50 is formed in a part of the extension 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 at 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 connection lead 20 is 2.0mm to 3.0mm at a portion other than the thin plate portion 50. The thickness of the thin plate portion 50 is-0.5 mm to-1.0 mm relative to the other portions of the connecting leads 20.

Further, a step 51 is formed on the surface of the extension portion 42A facing the side of the leg portion 32B at the boundary between the thin plate portion 50 and the portion other than the thin plate portion 50. On the surface of the extension portion 42A facing the leg portion 32B, the surface of the thin plate portion 50 is located on the opposite side of the leg portion 32B from the surface of the portion other than the thin plate portion 50 due to the step 51. On the surface of the extension portion 42A facing the opposite side of the leg portion 32B, a step or the like is not formed at the boundary between the thin plate portion 50 and the portion other than the thin plate portion 50.

In the present embodiment, the leg portions 32A and 32B are formed to be plane-symmetrical or substantially plane-symmetrical with each other about the central surface of the connecting lead 20 in the width direction of the top plate portion 31, except that the thin plate portion 50 is formed in the leg portion 32A. The connecting lead 20 is formed to be plane-symmetrical or substantially plane-symmetrical about the center plane of the top plate 31 in the width direction, except for the thin plate portion 50 formed in 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 connection leads 20 are formed of 1 plate member 60. The plate member 60 includes portions 61, 62A, 62B. When the connection lead 20 is formed, 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 to one side in the thickness direction (plate thickness direction) of the portion 61 with respect to the portion 61. Further, the portion 62B is bent with respect to the portion 61 at the bending position 63B by bending. At this time, the portion 62B is bent with respect to the portion 61 to the side where the portion 62A is bent in the thickness direction of the portion 61. Thereby, the top plate 31 is formed by the portion 61.

Bending positions 45A1, 45A2, 48A are formed at the portion 62A by bending, and the thin plate portion 50 is formed at the portion 62A by pressing. Thus, the leg portion 32A is formed by the portion 62A. Bending positions 45B1, 45B2, 48B are formed at the portion 62B by bending. Thus, the leg portion 32B is formed by the portion 62B.

In another example, the top plate 31 and the legs 32A and 32B are formed of different members. The 3 members are integrated by welding or the like, thereby forming the connection lead 20.

As shown in fig. 2, 5, and the like, in the internal cavity 8 of the battery 1, the top plate portions 31 of the pair of connection leads 20 are arranged between the electrode group 2 and the electrode pressing member 25 in the height direction of the battery 1, and are sandwiched between the electrode group 2 and the electrode pressing member 25. For each connection lead 20, the extending direction (longitudinal direction) of the top plate 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 31 coincides with or substantially coincides with the longitudinal direction of the battery 1. The thickness direction (plate thickness direction) of the top plate 31 is identical or substantially identical to the height direction of the battery 1 for each connection lead 20. In the battery 1, the top plate 31 of each of the pair of connecting leads 20 is connected to a corresponding one of the electrode terminals 21, that is, a corresponding one of the positive electrode terminal and the negative electrode terminal. Each connection lead 20 is inserted into a corresponding one of the electrode terminals 21 through the through hole 36 of the top plate constituting portion 33. The connection leads 20 are connected to the corresponding one of the electrode terminals 21 by caulking or the like at the through holes 36.

In the internal cavity 8 of the battery 1, the leg portions 32A and 32B of the pair of connecting leads 20 are arranged between the electrode group 2 and the corresponding one of the side walls 11 in the lateral direction of the battery 1. The width direction of each leg portion 32A, 32B of each connecting lead 20 is aligned or substantially aligned with the lateral direction of the battery 1. The connection leads 20 are arranged outside the respective legs 32A and 32B at the connection positions of the corresponding one of the through holes 36, that is, the electrode terminals 21 in the lateral direction of the battery 1. Accordingly, the top plate portions 31 of the connecting leads 20 extend from the corresponding one of the electrode terminals 21 to the connecting position of the leg portions 32A, 32B toward the lateral outside of the battery 1.

The leg portions 32A and 32B of each connecting lead 20 are bent toward the bottom wall 6 side with respect to the top plate 31 in the height direction of the battery 1. The leg portion 32B faces the leg portion 32A from one side in the longitudinal direction of the battery 1 for each connection lead 20.

In addition, each connection lead 20 is connected to a corresponding one of the current collecting tabs 13C and 14C at both the extension portion (first extension portion) 42A of the leg portion (first leg portion) 32A and the extension portion (second extension portion) 42B of the leg portion (second leg portion) 32B. That is, the connecting leads 20 are each formed with a joint 55 joined to a corresponding one of the current collecting tabs 13C and 14C at both of the extending portions 42A and 42B. In the present embodiment, the bonding portion 55 is formed in the thin plate portion 50 at the extending portion 42A of each of the connection leads 20. Therefore, the thickness (plate thickness) of the leg portion 32A at the joint portion 55 of the extension portion 42A is smaller than the thickness of the leg portion 32A between the top plate portion 31 and the joint portion 55 of the extension portion 42A for the connection lead 20.

In the present embodiment, the bundling portions 18 of the current collecting tabs 13C and 14C are sandwiched between the corresponding one of the extending portions 42A and 42B of the connecting lead 20. That is, the binding portions 18 of the current collecting tabs 13C and 14C are engaged with the engaging 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. In the extension portion 42A (thin plate portion 50), the binding portion 18 is in contact with a surface facing the side of the foot portion 32B. In the extension portion 42A, a step 51 is formed on a surface facing the side where the bundling portion 18 contacts.

The operation of bonding the collector tab (13C or 14C) to the connecting lead 20 will be described. Each of the current collecting tabs 13C and 14C is bonded to a corresponding one of the connecting leads 20 by, for example, ultrasonic welding using an ultrasonic horn. In the operation of bonding the collector tab (13C or 14C) to the connection lead 20, first, the bundling portion 18 is arranged between the extension portion 42A of the leg portion 32A and the extension portion 42B of the leg portion 32B. At this time, the bundling portion 18 is inserted between the leg portions 32A, 32B from between the protruding end of the leg portion 32A and the protruding end of the leg portion 32B. In the present embodiment, the end plate portion 47A is bent to a side away from the leg portion 32B with respect to the extension portion 42A, and the end plate portion 47B is bent to a side away from the leg portion 32A with respect to the extension portion 42B. Therefore, the bundling part 18 is easily inserted between the leg parts 32A, 32B, and the bundling part 18 is easily arranged between the extension parts 42A, 42B.

The ultrasonic horn is brought into contact with the thin plate portion 50 of the extension portion 42A in a state where the bundling 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. At this time, the ultrasonic horn is brought into contact with the thin plate portion 50 from the opposite side of the foot portion 32B. The current collector sheet (13C or 14C) is bonded to the connecting lead 20 at the extending portions 42A, 42B using ultrasonic vibration transmitted from the ultrasonic horn, and a bonding portion 55 with the current collector sheet (13C or 14C) is formed at the thin plate portion 50 and the extending portion 42B of the extending portion 42A. In the present embodiment, since the thin plate portion 50 is provided in the extension portion 42A, the bondability between the current collector tab (13C or 14C) and the extension portions 42A, 42B is improved. Therefore, the bundling portion 18 of the collector tab (13C or 14C) is appropriately joined to the connecting lead 20 at the joining portion 55 of the extension portion 42A, 42B.

Since the welding is performed in a state where the bundling part 18 is sandwiched between the extension parts 42A, 42B, even if the backup lead is not provided, the extension parts 42A, 42B can prevent the bundling part 18 of the collector tab (13C or 14C) from being exposed. That is, even if the backup lead is not provided, the extension portions 42A and 42B can protect the bundling portion 18 of the collector tab (13C or 14C) during welding using the ultrasonic horn.

In the connection lead 20 of the present embodiment, the connection position between the leg connection portion 41A and the top plate 31 is separated from the connection position between the leg connection portion 41B and the top plate 31 by a distance (first distance) L1 in the width direction of the top plate 31. The distance L1 is a certain amount and is larger than the distance (second distance) L2 between the extension portions 42A and 42B. Therefore, the portion of the top plate 31 to which the leg portions 32A and 32B are connected and the vicinity thereof, that is, the top plate constituent portion 35 can be increased in the width direction of the top plate 31. The width dimension of the top plate 31 at the top plate forming portion 35 becomes larger, so that the cross-sectional area of the top plate 31 can be ensured to be large for the top plate forming portion 35. That is, by increasing the distance L1, the width of the top plate forming portion 35 can be increased, and the cross-sectional area of the top plate forming portion 35 can be increased. As described above, the cross-sectional area of the top plate portion 31 at the top plate constituting portion 35 is ensured to be large, thereby ensuring that the resistance of the connecting lead 20 is low. As a result, the current path between each of the current collecting tabs 13C and 14C and the corresponding one of the electrode terminals 21 is ensured to have low resistance.

In the connecting lead 20 of the present embodiment, the extension portion 42A is provided on the leg portion 32A at a position apart from the connection position with the top plate portion 31, and the extension portion 42B is provided on the leg portion 32B at a position apart from the connection position with the top plate portion 31. The distance (second distance) L2 is between the extension portions 42A and 42B. The distance L2 is smaller than the distance L1, and is small or zero. By reducing the distance L2 between the extension portions 42A, 42B, it is possible to ensure high rigidity of the connection lead 20. Therefore, in the battery 1, the resistance of each connection lead 20 to impact is improved.

In the present embodiment, the thin plate portion 50 of the extension portion 42A is connected to the bundling portion 18 of the current collecting tab (13C or 14C) on the surface facing the side where the extension portion 42B is located. In addition, the surface of the extension portion 42A facing the side of the extension portion 42B (the side where the bundling portion 18 is in contact with) is recessed toward the side opposite to the bundling portion 18 (the leg portion 32B) with respect to the portion other than the thin plate portion 50 due to the step 51. Therefore, the thickness of the bundling section 18 can be absorbed by the depressions of the thin plate section 50 with respect to the portions other than the thin plate section 50, and the distance L2 between the extension portions 42A and 42B can be further reduced. Thereby, the rigidity of the connection lead 20 is further improved.

In the connecting lead 20 of the present embodiment, the leg portion 32A is provided with the relay portion 43A2 between the leg connecting portion 41A and the extension portion 42A, and the relay portion 43A2 is inclined with respect to the extension portion 42A. In the connection lead 20, the leg portion 32B is provided with a relay portion 43B2 between the leg connection portion 41B and the extension portion 42B, and the relay portion 43B2 is inclined with respect to the extension portion 42B. Accordingly, in the internal cavity 8 of the battery 1, the relay parts 43A2 and 43B2 of the connection lead 20 are arranged in a state of being inclined with respect to the longitudinal direction and the height direction of the battery 1. Therefore, when the battery 1 is impacted from the longitudinal direction or the like, the load acting on each connection lead 20 is dispersed and reduced by the relay parts 43A2 and 43B 2. In this way, in the battery 1, the resistance of each connection lead 20 to impact is further improved.

In the present embodiment, the current collecting tabs 13C and 14C are each configured to bind a plurality of belt-shaped portions to one portion of the binding portion 18. The current collecting tabs 13C and 14C are joined to a corresponding one of the connecting leads 20 at a bundling portion 18 where a plurality of belt-shaped portions are bundled at one position. Since the current collecting tabs 13C and 14C are connected to the corresponding one of the connecting leads 20 in a state where the plurality of band-shaped portions are bundled together, stress (load) acting on the root portions of the protruding portions in the electrode group 2 is reduced for each of the current collecting tabs 13C and 14C of the battery 1. This improves the resistance of each of the current collecting sheets 13C and 14C.

(modification)

A modification of the first embodiment described above will be described below. In the following modification, only the modification of the first embodiment will be described, and the same portions as those of the first embodiment will be omitted.

In the first modification shown in fig. 7, the wide portion 53 is formed in each connection lead 20. The wide portion 53 is integrally formed with a portion of the thin plate portion 50 formed in the extension portion (first extension portion) 42A. The wide portion 53 has a larger width (plate width) than other portions of the leg portion 32B and the leg portion 32A. Therefore, the width of the leg portion 32A at 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 the portions other than the wide portion 53 are 6.0mm to 7.0mm, respectively. The width of the wide portion 53 is +0.5mm to +1.0mm with respect to the other portions of the leg portion 32A. In addition, the wide portion 53 protrudes in the width direction of the leg portion 32A (the extending direction of the top plate portion 31) toward the other portion of the leg portion 32A, that is, toward the side where the through hole 36 is located, which is the connection position of the electrode terminal 21. The wide portion 53 does not protrude in the width direction of the leg portion 32A toward the side opposite to the side where the through hole 36 is located with respect to the other portion of the leg portion 32A.

In this modification, too: the bundling portions 18 of the current collecting tabs 13C and 14C are sandwiched between the corresponding one of the extension portions 42A and 42B of the connecting lead 20. Further, in each connection lead 20, a joint 55 to be joined to a corresponding one of the current collecting tabs 13C and 14C is formed in both the extension portions 42A and 42B. In the present modification, the bonding portion 55 is formed at a portion where the wide portion 53 is formed in the thin plate portion 50 of the extension portion 42A of each of the connection leads 20. Therefore, for each connection lead 20, the width (plate width) of the leg portion 32A at the joint portion 55 of the extension portion 42A is larger than the width of the leg portion 32A between the top plate portion 31 and the joint portion 55 of the extension portion 42A. In the internal cavity 8 of the battery 1, the wide portions 53 of the connecting leads 20 protrude toward the electrode group 2 with respect to the other portions of the leg portions 32A in the lateral direction of the battery 1.

In the present modification, the wide portion 53 is provided in a part of the thin plate portion 50. Therefore, the cross-sectional area of the leg portion 32A can be ensured to a certain extent also in the thin plate portion 50 of the leg portion 32A. In addition, each connecting lead 20 has a joint 55 joined to a corresponding one of the current collecting tabs 13C and 14C at the wide portion 53. Therefore, at the joint 55, the contact area of the connection lead 20 with the corresponding one of the current collecting tabs 13C and 14C increases. Therefore, in the present modification, the lower resistance can be more appropriately ensured in the current path between the current collecting tabs 13C and 14C and the corresponding one of the electrode terminals 21.

In addition, the wide portion 53 of each connecting lead 20 protrudes toward the electrode group 2 with respect to the other portion of the leg portion 32A in the lateral direction of the battery 1. Therefore, even if the wide portion 53 is provided, the insertion property of the assembly body such as the electrode group 2 and the pair of connection leads 20 into the internal cavity 8 of the outer case 3 can be ensured at the time of manufacturing the battery 1.

In the above embodiment and the like, the bundling portion 18 in which the plurality of belt-shaped portions are bundled at one position is joined to the corresponding one of the connecting leads 20 with respect to the current collecting tabs 13C and 14C, but the present invention is not limited thereto. In the above embodiment and the like, the binding portion 18 of the corresponding one of the current collecting tabs 13C, 14C is sandwiched between the extension portions 42A, 42B, and the joining portion 55 to be joined to the corresponding one of the current collecting tabs 13C, 14C is formed in both the extension portions 42A, 42B, but the present invention is not limited thereto.

For example, in the second modification shown in fig. 8, the current collecting tabs 13C and 14C are each configured to bundle a plurality of belt-shaped portions at 2, and the current collecting tabs 13C and 14C are each provided with 2 bundle portions 18A and 18B. In the present modification, the bundling parts (clamped parts) 18A, 18B are joined to the corresponding one of the connecting leads 20 in a state of being clamped between the extension setting parts 42A, 42B. In this modification, too: a joint 55 to be joined to a corresponding one of the current collecting tabs 13C and 14C is formed in both the extending portions 42A and 42B of each connecting lead 20. In the example of fig. 8, the bundling part 18B is sandwiched by the extension parts 42A and 42B at a position closer to the top plate 31 than the bundling part 18A. In the present modification, the extending portion 42A is provided with a joint 55 that is joined to each of the bundling portions (clamped portions) 18A and 18B in the thin plate portion 50.

In the connection lead 20 according to the third modification shown in fig. 9, the end plate 47A and the bending position 48A are not formed in the leg portion 32A, and the extension portion (first extension portion) 42A forms a protruding end of the leg portion 32A protruding from the top plate 31. In addition, the end plate 47B and the bending position 48B are not formed in the leg portion 32B, and the extension portion (second extension portion) 42B forms a protruding end of the leg portion 32B protruding from the top plate 31. In the present modification, the thin plate portion 50 is not formed in the extension portion 42A. In the present modification, the current collecting tabs 13C and 14C are each bundled together at one portion, and each of the current collecting tabs 13C and 14C includes only 1 bundling portion 18.

However, in the present modification, the bundle part 18 is not sandwiched between the extension parts 42A and 42B for each connection lead 20. In the present modification, the bundling section 18 is joined to the extension 42A on the surface facing the opposite side of the extension 42B. That is, the connection leads 20 are each formed with a joint 55 joined to a corresponding one of the current collecting tabs 13C and 14C on a surface of the extension portion 42A facing the opposite side to the extension portion 42B. Therefore, the joint 55 is formed only in the extension portion 42A of the leg portion 32A for each connection lead 20. In the present modification, the bundling section 18 is joined to the extension section 42A in a state sandwiched by the backup leads 56. In manufacturing the battery 1, when welding is performed using an ultrasonic horn, for example, the ultrasonic horn is brought into contact with the backup lead 56. At this time, the backup lead 56 prevents the bundle part 18 from being exposed, and protects the bundle part 18 of the collector sheet (13C or 14C).

In the fourth modification shown in fig. 10, as in the second modification, the current collecting tabs 13C and 14C are each bundled at 2 in the plurality of band-shaped portions, and the current collecting tabs 13C and 14C each include 2 bundling portions 18A and 18B. 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, the connecting leads 20 are formed with the joining portions 55 joined to the corresponding one of the current collecting tabs 13C and 14C on the surface of the extension portion 42A facing the opposite side to the extension portion 42B. Therefore, the joint 55 is formed only in the extension portion 42A of the leg portion 32A for each connection lead 20. The bundling parts 18A and 18B are joined to the extension part 42A in a state sandwiched by the backup leads 56. In the example of fig. 10, the bundling part 18B is joined to the extension-set part 42A at a position closer to the top plate 31 than the bundling part 18A.

In the fifth modification shown in fig. 11, the current collecting tabs 13C and 14C each include 2 bundling portions 18A and 18B, as in the second modification and the like. In the present modification, the bundling section 18A is joined to the surface of the extension 42A facing the opposite side of the extension 42B, and the bundling section 18B is joined to the surface of the extension 42B facing the opposite side of the extension 42A. Therefore, the connection leads 20 are formed with the joint portions 55 joined to the corresponding one of the current collecting tabs 13C and 14C 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 opposite side of the extension portion 42A. Therefore, the joint 55 is formed in both the extending portion 42A of the leg portion 32A and the extending portion 42B of the leg portion 32B for each connection lead 20.

In the present modification, each connecting lead 20 does not sandwich the bundling portion 18A, 18B of the corresponding one of the collector tabs 13C, 14C between the extending portions 42A, 42B. The bundling part 18A is joined to the extension part 42A in a state sandwiched by the backup lead 56, and the bundling part 18B is joined to the extension part 42B in a state sandwiched by the backup lead 56. When the battery 1 is manufactured, for example, when welding is performed using an ultrasonic horn, the ultrasonic horn is brought into contact with one of the backup lead 56 of the clamp bundling part 18A and the backup lead 56 of the clamp bundling part 18B. In the example of fig. 11, the distance from the top plate 31 to the bundling unit 18A is the same as or substantially the same as the distance from the top plate 31 to the bundling unit 18B.

In the sixth modification shown in fig. 12, the current collecting tabs 13C and 14C each include 2 bundling portions 18A and 18B, similarly to the fifth modification. The bundling section 18A is joined to the surface of the extension 42A facing the opposite side of the extension 42B, and the bundling section 18B is joined to the surface of the extension 42B facing the opposite side of the extension 42A. Therefore, in each connection lead 20, a joint 55 that is joined to a corresponding one of the current collecting tabs 13C and 14C is formed on a surface of the extension portion 42A facing the opposite side of the extension portion 42B and a surface of the extension portion 42B facing the opposite side of the extension portion 42A. The bundling parts 18A and 18B are held by the backup lead 56, respectively. However, in the present modification, the bundling portion 18B is joined to the connecting wire 20 at a position closer to the top plate 31 than the bundling portion 18A.

In the above embodiment and the like, the relay portion 43A2 is extended and provided in a state of being inclined with respect to the extension portion 42A in the leg portion 32A, and the relay portion 43B2 is extended and provided in a state of being inclined with respect to the extension portion 42B in the leg portion 32B, but the present invention is not limited thereto.

In the seventh modification shown in fig. 13, the relay portion 43A2 of the leg portion 32A and the relay portion 43B2 of the leg portion 32B are provided so as to extend in the width direction of the top plate portion 31 for each connection lead 20. Therefore, in the battery 1, the relay portions 43A2, 43B2 of the respective connection leads 20 are provided to extend in the longitudinal direction. In the present modification, the bending angle of the intermediate portion 43A2 at the bending position 45A1 with respect to the intermediate portion 43A1 and the bending angle of the intermediate portion 43A2 at the bending position 45A2 with respect to the extension portion 42A are respectively 90 degrees or substantially 90 degrees. The bending angle of the intermediate portion 43B2 at the bending position 45B1 with respect to the intermediate portion 43B1 and the bending angle of the intermediate portion 43B2 at the bending position 45B2 with respect to the extension portion 42B are respectively 90 degrees or substantially 90 degrees.

In the present modification, the leg portion 32A is provided with the relay portion 43A2 extending from the bending position 45A1 to the bending position 45A2 toward the side where the leg portion 32B is located. The leg portion 32B is provided with the relay portion 43B2 extending from the bending position 45B1 to the bending position 45B2 toward the side of the leg portion 32A. In this modification, too: the bent portion (first bent portion) bent with respect to the relay portion 43A1 and the extension portion 42A is formed by the relay portion 43A2, and the bent portion (second bent portion) bent with respect to the relay portion 43B1 and the extension portion 42B is formed by the relay portion 43B 2. In this modification, as in the first embodiment and the like, the connecting leads 20 sandwich the bundling portions 18 of the corresponding one of the collector tabs 13C, 14C between the extension portions 42A, 42B, and form the joint portions 55 joined to the corresponding one of the collector tabs 13C, 14C in both the extension portions 42A, 42B.

In the above embodiment and the like, the leg portion 32A has 2 bending positions 45A1 and 45A2 in addition to the bending position at the leg connecting portion 41A in the intermediate portion (first intermediate portion) between the top plate portion 31 (leg connecting portion 41A) and the extension portion 42A, but the present invention is not limited thereto. Similarly, in the above embodiment and the like, the leg portion 32B has 2 bending positions 45B1 and 45B2 formed in the intermediate portion (second intermediate portion) between the top plate portion 31 (leg connecting portion 41B) and the extension portion 42B, in addition to the bending position at the leg connecting portion 41B, but the present invention is not limited thereto.

In the eighth modification shown in fig. 14, in the leg portion 32A, only 1 bending position 45A1 is formed in the intermediate portion (first intermediate portion) between the top plate portion 31 (leg connecting portion 41A) and the extension portion 42A, except for the bending position at the leg connecting portion 41A. In addition, in the leg portion 32B, only 1 bending position 45B1 is formed in the intermediate portion (second intermediate portion) between the top plate portion 31 (leg connecting portion 41B) and the extension portion 42B, except for the bending position at the leg connecting portion 41B. In the present modification, the leg portion 32A is relayed only by the relay portion 43A1 between the leg portion 41A and the extension portion 42A, and the leg portion 32B is relayed only by the relay portion 43B1 between the leg portion 41B and the extension portion 42B.

In the present modification, the relay portion 43A1 is connected to the top plate 31 via the leg connection portion 41A, and is connected to the extension portion 42A at the bending position 45 A1. The relay portion 43A1 is bent with respect to the top plate 31 at the foot connecting portion 41A, and is bent with respect to the extension portion 42A at the bending position 45 A1. The intermediate portion (first bending portion) 43A1 is bent at the bending position 45A1 toward a side away from the leg portion 32B with respect to the extension portion 42A. The intermediate portion 43A1 of the foot connecting portion 41A has an obtuse angle of 150 degrees or less with respect to the top plate 31. The intermediate portion 43A1 at the bending position 45A1 has an acute angle of 60 degrees or less with respect to the extending portion 42A. Since the relay portion 43A1 is formed as described above, the relay portion 43A1 is inclined with respect to the extension portion 42A in a state where the portion closer to the extension portion (first extension portion) 42A is closer to the leg portion 32B.

The relay portion 43B1 is formed to be plane-symmetrical or substantially plane-symmetrical with respect to the relay portion 43A1 about the center surface of the connecting lead 20 in the width direction of the top plate 31. The bending position 45B1 is arranged to be surface-symmetrical or substantially surface-symmetrical with respect to the bending position 45B1 about the center surface of the connecting lead 20 in the width direction of the top plate 31. Therefore, the intermediate portion (second bending portion) 43B1 is bent at the bending position 45B1 toward the side away from the leg portion 32A with respect to the extension portion 42B. The relay portion 43B1 is inclined with respect to the extension portion 42B in a state where the closer to the extension portion (second extension portion) 42B is to the leg portion 32A.

In the ninth modification shown in fig. 15, 3 bending positions 45A1, 45A2, 45A3 are formed in the leg portion 32A in addition to the bending positions at the leg connecting portion 41A in the intermediate portion (first intermediate portion) between the top plate portion 31 (leg connecting portion 41A) and the extension portion 42A. In addition, in the leg portion 32B, 3 bending positions 45B1, 45B2, 45B3 are formed in the intermediate portion (second intermediate portion) between the top plate portion 31 (leg connecting portion 41B) and the extension portion 42B, except for the bending position at the leg connecting portion 41B. In the present modification, the leg portion 32A and the extension portion 42A are relayed via the relay portions 43A1, 43A2, and 43A3 in this order from the side close to the leg portion 41A, and the leg portion 32B and the extension portion 42B are relayed via the relay portions 43B1, 43B2, and 43B3 in this order from the side close to the leg portion 41B.

In the present modification, the relay portion 43A1 is connected to the top plate 31 via the leg connection portion 41A, and is connected to the relay portion 43A2 at the bending position 45 A1. 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 in the thickness direction of the top plate portion 31. The relay portion 43A1 is bent with respect to the top plate 31 at the leg connecting portion 41A, and is bent with respect to the relay portion 43A2 at the bending position 45 A1. The relay portion 43A1 is bent toward the leg portion 32B with respect to the relay portion 43A2 at the bending position 45 A1. The intermediate portion 43A1 at the foot connecting portion 41A has an acute angle of 30 degrees or more with respect to the bending angle of the top plate portion 31. The bending angle of the intermediate portion 43A1 at the bending position 45A1 with respect to the intermediate portion 43A2 is an acute angle of 60 degrees or less.

The intermediate portion 43A3 is bent with respect to the intermediate portion 43A2 at the bending position 45A2, and is bent with respect to the extension portion 42A at the bending position 45 A3. The intermediate portion (first bending portion) 43A3 is bent at the bending position 45A3 toward a side away from the leg portion 32B with respect to the extension portion 42A. The bending angle of the intermediate portion 43A3 at the bending position 45A2 with respect to the intermediate portion 43A2, and the bending angle of the intermediate portion 43A3 at the bending position 45A3 with respect to the extension portion 42A are respectively greater than 0 degrees and less than 90 degrees. Since the relay portion 43A3 is formed as described above, the relay portion 43A3 is inclined with respect to the extension portion 42A in a state where the portion closer to the extension portion (first extension portion) 42A is closer to the leg portion 32B.

The relay portion 43B1 is formed to be plane-symmetrical or substantially plane-symmetrical with respect to the relay portion 43A1, the relay portion 43B2 is formed to be plane-symmetrical or substantially plane-symmetrical with respect to the relay portion 43A2, and the relay portion 43B3 is formed to be plane-symmetrical or substantially plane-symmetrical with respect to the relay portion 43A3, with respect to the central plane of the connection lead 20 in the width direction of the top plate 31 as a center. The bending position 45B1 is disposed to be surface-symmetrical or substantially surface-symmetrical with respect to the bending position 45A1, the bending position 45B2 is disposed to be surface-symmetrical or substantially surface-symmetrical with respect to the bending position 45A2, and the bending position 45B3 is disposed to be surface-symmetrical or substantially surface-symmetrical with respect to the bending position 45A3, with respect to the central surface of the connecting lead 20 in the width direction of the top plate 31 as a center. Therefore, the intermediate portion (second bending portion) 43B3 is bent at the bending position 45B3 toward the side away from the leg portion 32A with respect to the extension portion 42B. The relay portion 43B3 is inclined with respect to the extension portion 42B in a state where the closer to the extension portion (second extension portion) 42B is to the leg portion 32A.

In addition, in a modification, in the leg portion 32A of each connection lead 20, 4 or more bending positions (45 A1, 45A2, ··) are formed in addition to the bending positions at the leg connecting portion 41A in the intermediate portion (first intermediate portion) between the top plate portion 31 (leg connecting portion 41A) and the extension portion 42A. In addition, at the leg portion 32B of each connecting lead 20, 4 or more bending positions (45B 1, 45B2, ··) are formed in addition to the bending positions at the leg connecting portion 41B at the intermediate portion (second intermediate portion) between the top plate portion 31 (leg connecting portion 41B) and the extension portion 42B.

In the above embodiment and the like, the current collecting tabs 13C and 14C are each cut from the electrode group 2 at the portions on both sides thereof with respect to the bundling portion 18 in the width direction of the electrode group 2, but the present invention is not limited thereto. In the tenth modification shown in fig. 16, at the time of manufacturing the electrode group 2, after the bundling sections 18 are formed in the current collecting tabs 13C and 14C, only one side portion of the current collecting tabs 13C and 14C is cut from the electrode group 2 with respect to the bundling section 18 in the width direction of the electrode group 2. Therefore, the current collecting tabs 13C and 14C do not cut the other side portion of the electrode group 2 from the bundling portion 18 in the width direction of the electrode group 2. Therefore, in the electrode group 2 of the battery 1, the curved surface portion 17 is formed at a portion on one side of the bundling portion 18 in the width direction of the electrode group 2 with respect to each of the current collecting tabs 13C, 14C. The current collecting tabs 13C and 14C do not need to be cut off from one side of the curved surface portion 17, and the formation of the electrode group 2 is facilitated.

In the present modification, as in the first embodiment and the like, the connecting leads 20 sandwich the bundling portions (clamped portions) 18 of the corresponding one of the collector tabs 13C, 14C between the extension portions 42A, 42B. The current collecting tabs 13C and 14C are joined to the corresponding one of the connecting leads 20 via the extending portions 42A and 42B with the binding portion 18 interposed therebetween. In the battery 1, the curved surface portion 17 is provided on the side of the top plate portion 31 of the corresponding one of the connecting leads 20 with respect to the bundling portion (clamped portion) 18 for each of the current collecting tabs 13C and 14C. That is, the curved surface portion 17 is disposed on the side closer to the lid member 5 than the bundling portion 18 is, for each of the collector tabs 13C, 14C. In the internal cavity 8, the curved surface portions of the current collecting tabs 13C and 14C are arranged between the corresponding one of the relay portions (first relay portion) 43A1 and the relay portion (second relay portion) 43B1 of the connecting lead 20.

In the above embodiment and the like, the leg portions 32A and 32B are formed to be plane-symmetrical or substantially plane-symmetrical with each other about the center surface of the connecting lead 20 in the width direction of the top plate portion 31, except for the thin plate portion 50 and the like formed in the leg portion 32A, but the present invention is not limited thereto. In the eleventh modification shown in fig. 17, the leg portions 32A and 32B are non-planar symmetrical with each other about the center surface of the connecting lead 20 in the width direction of the top plate portion 31. Therefore, in the above embodiment and the like, the central surface of the connecting lead 20 in the width direction of the top plate 31 is defined between the extension portions 42A, 42B, but in the present modification, the central surface of the connecting lead 20 in the width direction of the top plate 31 is not defined between the extension portions 42A, 42B.

In the present modification, the current collecting tabs 13C, 14C are each joined to a corresponding one of the connecting leads 20 on the surface of the extension portion 42A facing the opposite side to the extension portion 42B. At this time, the current collecting tabs 13C, 14C are connected to the extension portion 42A in a state where the bundling portion 18 is sandwiched by the backup leads 56. By using the connection lead 20 according to this modification, for example, when the bundling part 18 is formed in the current collecting tab (13C or 14C) so as to deviate from the center position of the electrode group 2 in the thickness direction of the electrode group 2, the current collecting tab (13C or 14C) is easily connected to the connection lead 20.

In the twelfth modification shown in fig. 18, the leg portion 32B, which is one of the leg portions 32A and 32B, is not formed at the bending position other than the bending position at the leg connecting portion 41B in the intermediate portion 43B1 between the top plate portion 31 (the leg connecting portion 41B) and the extension portion 42B. The leg portion 32B extends straight or substantially straight in the thickness direction of the top plate 31 from the leg connecting portion 41B to the protruding end. That is, the leg portion 32B is provided to extend straight or substantially straight without being bent in the entirety of the relay portion 43B1 and the extending portion 42B. However, in this modification, too, it is: in the leg portion 32A which is not a straight one of the leg portions 32A, 32B, 1 or more bending positions (45 A1, 45A2, etc.) are formed in addition to the bending positions at the leg connecting portion 41B in the intermediate portion between the top plate portion 31 (the leg connecting portion 41A) and the extension portion 42A.

In the present modification as well, the leg portions 32A, 32B are non-planar symmetrical to each other about the center surface of the connecting lead 20 in the width direction of the top plate portion 31, as in the eleventh modification. Therefore, the central surface of the connecting lead 20 in the width direction of the top plate 31 is not defined between the extending portions 42A and 42B. By using the connection lead 20 according to the present modification, it is easy to connect the current collecting tab (13C or 14C) to the connection lead 20, for example, when the bundling part 18 is formed in the current collecting tab (13C or 14C) so as to deviate from the center position of the electrode group 2 in the thickness direction of the electrode group 2, as in the eleventh modification. In the present modification, since the bending position is not formed on the one leg portion 32B except for the bending position at the leg connecting portion 41B, the formation of the connecting lead 20 is facilitated.

In each of the above-described modifications, as in the first embodiment and the like, the connecting lead 20 includes the top plate 31 and the pair of leg portions 32A, 32B, and the pair of leg portions 32A, 32B are bent with respect to the top plate 31 on the same side as each other in the thickness direction of the top plate 31. The connection position of the foot connection portion 41A of the foot portion 32A and the top plate 31 is separated by a distance (first distance) L1 in the width direction of the top plate 31 from the connection position of the foot connection portion 41B of the foot portion 32B and the top plate 31. The distance L1 has a certain size. Therefore, in the same manner as in the first embodiment and the like, in each modification, it is: in the portion connecting the leg portions 32A, 32B and the vicinity thereof, that is, in the top plate constituting portion 35, the width dimension of the top plate portion 31 can be increased, and the cross-sectional area of the top plate portion 31 at the top plate constituting portion 35 can be increased. Therefore, in each modification, too: by securing a large cross-sectional area of the top plate portion 31 at the top plate constituting portion 35, the resistance of the connecting lead 20 is secured to be low, and the resistance is secured to be low in the current path between each of the current collecting tabs 13C, 14C and the corresponding one of the electrode terminals 21.

In each of the above modifications, the following are also included: the leg portion 32A is provided with an extension portion 42A so as to be away from the leg connecting portion 41A on the opposite side from the top plate portion 31, and the leg portion 32B is provided with an extension portion 42B so as to be away from the leg connecting portion 41B on the opposite side from the top plate portion 31. The distance between the extending portions 42A and 42B in the width direction of the top plate 31 is a distance (second distance) L2 smaller than the distance (first distance) L1. The distance L2 is for example small or zero. Since the distance L2 between the extension portions 42A and 42B is reduced, the rigidity of the connection lead 20 can be ensured in each modification as in the first embodiment and the like, and the resistance of each connection lead 20 to impact is improved in the battery 1.

In the above embodiment, the modified example, and the like, the thin plate portion 50 is not formed in either one of the leg portions 32A, 32B (the extending portions 42A, 42B) or in one of the leg portions 32A, 32B (the extending portions 42A, 42B). However, the thin plate portion 50 may be formed in both the extension portions 42A and 42B. At this time, the joint 55 that is joined to the bundling portion 18 of the corresponding one of the current collecting tabs 13C, 14C is formed in the thin plate portion 50 in each of the extension portions 42A, 42B.

When the thin plate portion 50 is formed in the extension portion 42A, the step 51, which is a recess of the thin plate portion 50 with respect to a portion other than the thin plate portion 50, may be formed on a surface facing the extension portion 42B, or may be formed on a surface facing the opposite side to the extension portion 42B. However, when the bundling part 18 is joined to the extension 42A with the bundling part 18 sandwiched between the extensions 42A, 42B, the recess is preferably formed on the surface facing the side of the extension 42B. This can absorb the thickness of the bundling section 18, and further reduce the distance L2 between the extension sections 42A and 42B. On the other hand, when the bundling part 18 is engaged with the extension setting part 42A on the surface facing the opposite side of the extension setting part 42B, the above-described recess is preferably formed on the surface facing the opposite side of the extension setting part 42B. Therefore, the recess of the thin plate portion 50 is preferably formed on the surface facing the side where the bundling portion 18 abuts on the extension portion 42A. The case where the thin plate portion 50 is formed on the extension portion 42B is also similar to the case where the thin plate portion 50 is formed on the extension portion 42A.

It is not necessary to provide both the positive electrode side connecting lead between the positive electrode collector tab 13C and the positive electrode terminal and the negative electrode side connecting lead between the negative electrode collector tab 14C and the negative electrode terminal with the same configuration as the connecting lead 20 of any of the above-described embodiments and modifications. That is, at least one of the positive electrode side connecting lead and the negative electrode side connecting lead may have the same structure as the connecting lead 20 of any one of the above-described embodiments and modifications.

According to at least one embodiment or example of these, with respect to the connection lead, the leg connection portions of the pair of leg portions are connected to the top plate portion at positions apart from each other by a first distance in the width direction of the top plate portion. The pair of leg portions are each provided with an extension portion at a position distant from the leg connecting portion toward the side opposite to the top plate portion, and a second distance smaller than the first distance is provided between the extension portions of the pair of leg portions. This can provide a connection lead which can ensure high rigidity and low resistance.

While the present utility model has been described with reference to several embodiments, these embodiments are presented by way of example and do not limit the scope of the utility model. These novel embodiments can be implemented in various other modes, and various omissions, substitutions, and changes can be made without departing from the scope of the utility model. These embodiments and modifications thereof are included in the scope and gist of the utility model, and are included in the utility model described in the claims and their equivalents.

Claims (10)

1. A connection lead for connecting a collector tab of an electrode group to an electrode terminal in a battery is characterized by comprising:

A top plate portion; and

a pair of leg portions which are bent with respect to the top plate portion toward the same side as each other in the thickness direction of the top plate portion,

one of the pair of legs, namely, the first leg is provided with:

a first leg connecting portion connected to the top plate portion; and

a first extending portion located away from the first leg connecting portion on a side opposite to the top plate portion,

the second leg, which is the other leg of the pair of legs, includes:

a second leg link portion connected to the top plate portion at a position separated from the first leg link portion by a first distance in a width direction of the top plate portion,

and a second extending portion which is located away from the second leg connecting portion on a side opposite to the top plate portion, and which has a second distance smaller than the first distance between the first extending portion of the first leg portion and the width direction of the top plate portion.

2. The connecting lead according to claim 1, wherein at least one of:

the first leg portion includes a first bending portion provided between the first leg connecting portion and the first extending portion and bending toward a side away from the second leg portion with respect to the first extending portion; the method comprises the steps of,

The second leg portion includes a second bending portion provided between the second leg connecting portion and the second extending portion and bent toward a side away from the first leg portion with respect to the second extending portion.

3. The connecting lead according to claim 2, wherein at least one of:

the first bending portion is inclined with respect to the first extension portion in a state that the closer to the first extension portion is to the second leg portion; the method comprises the steps of,

the second bending portion is inclined with respect to the second extension portion in a state that the second bending portion is closer to the first leg portion as the second bending portion is closer to the second extension portion.

4. A connecting lead according to any one of claims 1 to 3, characterized in that at least one of:

the first leg portion includes a first end plate portion which is provided on the opposite side of the top plate portion from the first extension portion, forms a protruding end of the first leg portion protruding from the top plate portion, and is bent toward a side away from the second leg portion from the first extension portion; the method comprises the steps of,

The second leg portion includes a second end plate portion that is provided on the opposite side of the top plate portion from the second extension portion, forms a protruding end of the second leg portion that protrudes from the top plate portion, and is bent toward a side away from the first leg portion from the second extension portion.

5. A battery, characterized by comprising:

the connecting lead of any one of claims 1 to 4;

an outer container having a bottom wall and a peripheral wall, wherein an internal cavity in which the connection leads are disposed is defined by the bottom wall and the peripheral wall;

an electrode group including a positive electrode and a negative electrode, and a current collecting tab bonded to the connection wire at least at one of the first extended portion of the first leg and the second extended portion of the second leg;

a lid member attached to the peripheral wall at an end portion on the opposite side of the bottom wall, the lid member closing an opening of the internal cavity of the outer container; and

and an electrode terminal attached to an outer surface of the cover member and connected to the top plate portion of the connection lead.

6. The battery of claim 5, wherein the battery is configured to provide the battery with a battery cell,

At least the first extension of the first leg is formed with a joint with the collector tab on the connection lead,

the thickness of the first leg portion at the joint portion of the first extension portion is smaller than the thickness of the first leg portion between the top plate portion and the joint portion of the first extension portion.

7. The battery according to claim 5 or 6, wherein,

at least the first extension of the first leg is formed with a joint with the collector tab on the connection lead,

the width of the first leg portion at the joint portion of the first extension portion is larger than the width of the first leg portion between the top plate portion and the joint portion of the first extension portion.

8. The battery according to claim 5 or 6, wherein,

a joint portion with the collector tab is formed on the connection lead at both the first extension portion of the first leg portion and the second extension portion of the second leg portion,

the current collecting tab includes a clamped portion that is joined to the joint portion in a state of being clamped between the first extended portion of the first leg portion and the second extended portion of the second leg portion.

9. The battery of claim 8, wherein the battery is configured to provide the battery with a battery cell,

in the electrode group, the positive electrode and the negative electrode are wound around a winding shaft,

the first leg portion includes a first relay portion that relays between the first leg connecting portion and the first extended portion,

the second leg portion includes a second relay portion that relays between the second leg connecting portion and the second extended setting portion,

the current collecting tab includes a curved surface portion that is provided on a side of the top plate portion of the connecting lead with respect to the clamped portion, and is disposed in the internal cavity between the first relay portion of the first leg portion and the second relay portion of the second leg portion.

10. The battery according to claim 5 or 6, wherein,

the current collecting sheet includes: a positive electrode collector tab protruding from the electrode group; and a negative electrode collector tab protruding in the electrode group to a side opposite to a side on which the positive electrode collector tab protrudes,

the electrode terminal includes a positive electrode terminal and a negative electrode terminal,

is at least one of the following cases: the connecting lead connects the positive electrode collector plate with the positive electrode terminal; and the connecting lead connects the negative electrode collector tab and the negative electrode terminal.

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