Battery and method for manufacturing the battery

Abstract

To provide a battery to secure a low electric resistance of a lead and to achieve higher output.SOLUTION: According to an embodiment, a battery includes an electrode group, a current collecting tab, a terminal, and a lead. The current collecting tab protrudes outwardly in a lateral direction in the electrode group, and the terminal is deviated from the electrode group in a height direction. The lead includes a top plate portion to which the terminal is connected, and a leg portion bent to the top plate portion toward a side of the electrode group in the height direction. A bending line of the leg portion to the top plate portion is along a depth direction, and the leg portion extends straight from a bending position to a far side end to the top plate portion. A leg edge surface facing one side in the depth direction is joined to the current collecting tab in an outer surface of the leg portion.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE Embodiments of the present invention relate to batteries and methods for making batteries. [Background technology]

[0002] Some batteries, such as lithium ion secondary batteries, have an electrode group including a positive electrode and a negative electrode housed in the internal cavity of an outer container. In this battery, the internal cavity of the outer container opens to one side in the height direction. A lid member is attached to the outer container, and the opening of the internal cavity is closed by the lid member. In the battery, a terminal is attached to the outer surface of the lid member, and the terminal is disposed offset from the electrode group to one side in the height direction. In the electrode group disposed in the internal cavity of the outer container, a current collecting tab protrudes outward in a lateral direction intersecting the height direction. A lead electrically connects the current collecting tab and the terminal. Thus, an electrical path is formed between the electrode group and the terminal by the lead.

[0003] In the above-mentioned batteries, it is required to ensure low electrical resistance in the leads that serve as electrical paths between the electrode group and the terminals, thereby realizing high output of the battery. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-61880 A Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a battery in which the electrical resistance of the leads is ensured to be low and high output is realized, and a method for manufacturing such a battery. [Means for solving the problem]

[0006] According to an embodiment, a battery includes an electrode group, a current collecting tab, a terminal, and a lead. The electrode group includes a positive electrode and a negative electrode, and is integrally formed. The current collecting tab protrudes outward in the lateral direction from the electrode group. The terminal is disposed offset from the electrode group in a height direction intersecting the lateral direction, and the lead electrically connects between the electrode group and the terminal. The current collecting tab includes a first tab extension portion extending along the height direction, and a second tab extension portion formed apart from the first tab extension portion in a depth direction intersecting both the lateral direction and the height direction, and extending along the height direction. The second tab extension portion is integrally formed with the first tab extension portion on the integral electrode group. The second tab extension includes an additional extension portion that extends beyond the first tab extension in the height direction toward the side where the terminal is located. The lead includes a top plate portion to which the terminal is connected, and a leg portion bent relative to the top plate portion toward the side where the electrode group is located in the height direction. The bending line of the leg portion relative to the top plate portion is formed along the depth direction, and the leg portion extends straight along the height direction from the bending position relative to the top plate portion to the distal end relative to the top plate portion. The leg portion of the lead is inserted between the first tab extension portion and the second tab extension portion from the side where the terminal is located in the height direction. The outer surface of the leg portion is provided with a first leg edge surface facing one side in the depth direction, and the first leg edge surface is joined to the first tab extension portion from the side where the second tab extension portion is located in the depth direction. A second leg edge surface facing the opposite side to the first leg edge surface is provided on the outer surface of the leg, and the second leg edge surface is joined to the second tab extension portion by an additional extension portion from the side where the first tab extension portion is located in the depth direction.

[0007] According to the battery manufacturing method of the embodiment, an electrode group is integrally formed from a positive electrode and a negative electrode, and a current collecting tab is formed on the electrode group so as to protrude outward in the longitudinal direction of the electrode group. In the manufacturing method, a first tab extension is formed on the current collecting tab along the width direction of the electrode group that intersects with the longitudinal direction, and a second tab extension is formed along the width direction, away from the first tab extension, in the thickness direction of the electrode group that intersects with both the longitudinal direction and the width direction. The second tab extension is formed integrally with the first tab extension on the integral electrode group. In the manufacturing method, an additional extension portion that extends beyond the first tab extension portion to one side in the width direction of the electrode group is formed on the second tab extension portion.In the manufacturing method, the leg is bent relative to the top plate to one side in the plate thickness direction of the top plate with the bend line aligned along the plate width direction of the top plate to form a lead, and the leg is formed straight from the bent position relative to the top plate to the distal end relative to the top plate. In the manufacturing method, the top plate of the lead is connected to a terminal. In the manufacturing method, the terminal to which the top plate is connected is disposed at a position offset from the electrode group in the width direction of the electrode group. This creates a state in which the additional extension portion of the second tab extension portion extends beyond the first tab extension portion toward the side where the terminal is located. At the same time, the leg of the lead is inserted between the first tab extension and the second tab extension from the side where the terminal is located in the width direction of the electrode group, so that the leg is arranged along the width direction of the electrode group from the bending position with respect to the top plate to the distal end with respect to the top plate. 1. The leg edge surface is joined to the first tab extension portion of the current collecting tab, Furthermore, by joining a second leg edge surface facing the opposite side to the first leg edge surface to the second tab extension portion of the current collecting tab by an additional extension portion, An electrical connection is made between the electrode group and the terminal. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view that diagrammatically illustrates a battery according to a first embodiment. [Diagram 2] FIG. 2 is a perspective view that shows the battery according to the first embodiment in a state where each component is disassembled. [Diagram 3] FIG. 3 is a perspective view that illustrates a schematic diagram of a lead of the battery according to the first embodiment. [Figure 4] FIG. 4 is a perspective view that illustrates a schematic electrical connection structure between an electrode group and a terminal via a lead in the battery according to the first embodiment. [Diagram 5] FIG. 5 is a cross-sectional view showing, in a cross section perpendicular or approximately perpendicular to the lateral direction of the battery, a schematic view of an electrical connection structure via leads between an electrode group and a terminal in the battery according to the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing an electrode group and a current collecting tab of the battery according to the first embodiment, in a cross section perpendicular or approximately perpendicular to the length direction of the electrode group. [Figure 7]FIG. 7 is a cross-sectional view showing, in a cross section perpendicular or approximately perpendicular to the lateral direction of the battery, a schematic view of an electrical connection structure via leads between an electrode group and a terminal in a battery according to a first modified example. [Figure 8] FIG. 8 is a cross-sectional view showing, in a cross section perpendicular or approximately perpendicular to the lateral direction of the battery, a schematic view of an electrical connection structure via leads between an electrode group and a terminal in a battery according to a second modified example. [Figure 9] FIG. 9 is a cross-sectional view showing, in a cross section perpendicular or approximately perpendicular to the lateral direction of the battery, a schematic view of an electrical connection structure via leads between an electrode group and a terminal in a battery according to a third modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment will be described with reference to the drawings.

[0010] (First embodiment) 1 and 2 show a battery 1 according to a first embodiment. In FIG. 2, the battery 1 is shown in a state in which each component is disassembled. As shown in FIG. 1 and FIG. 2, the battery 1 includes an electrode group 2, an outer container 3, and a lid member 5. Each of the outer container 3 and the lid member 5 is formed of a metal such as aluminum, an aluminum alloy, iron, copper, or stainless steel. Here, in the battery 1, a lateral direction (direction indicated by arrows X1 and X2), a height direction (direction indicated by arrows Y1 and Y2) intersecting (perpendicular or approximately perpendicular) with respect to the lateral direction, and a depth direction (direction indicated by arrows Z1 and Z2) intersecting (perpendicular or approximately perpendicular) with respect to both the lateral direction and the height direction are defined. In each of the battery 1 and the outer container 3, the dimension in the depth direction is smaller than the dimension in the lateral direction and the dimension in the height direction.

[0011] The outer container 3 includes a bottom wall 6 and a peripheral wall 7. The inner cavity 8 in which the electrode group 2 is housed is defined by the bottom wall 6 and the peripheral wall 7. In the outer container 3, the inner cavity 8 opens toward the opposite side to the side where the bottom wall 6 is located in the height direction. The peripheral wall 7 includes two pairs of side walls 11, 12. The pair of side walls 11 face each other in the lateral direction with the inner cavity 8 therebetween. The pair of side walls 12 face each other in the depth direction with the inner cavity 8 therebetween. Each of the side walls 11 extends continuously between the side walls 12 along the depth direction. Each of the side walls 12 extends continuously between the side walls 11 along the lateral direction. The cover member 5 is attached to the peripheral wall 7 at an end opposite to the bottom wall 6. Therefore, the cover member 5 closes the opening of the inner cavity 8 of the outer container 3. The cover member 5 and the bottom wall 6 face each other in the height direction with the inner cavity 8 therebetween.

[0012] The electrode group 2 includes a positive electrode 13 and a negative electrode 14. In the electrode group 2, a separator (not shown) is interposed between the positive electrode 13 and the negative electrode 14. The separator is made of an electrically insulating material, and electrically insulates the positive electrode 13 from the negative electrode 14.

[0013] The positive electrode 13 includes a positive electrode current collector 13A such as a positive electrode current collector foil, and a positive electrode active material-containing layer (not shown) supported on the surface of the positive electrode current collector 13A. The positive electrode current collector 13A is, but is not limited to, for example, an aluminum foil or an aluminum alloy foil, and has a thickness of about 10 μm to 20 μm. The positive electrode active material-containing layer includes a positive electrode active material, and may optionally include a binder and a conductive agent. Examples of the positive electrode active material include, but are not limited to, oxides, sulfides, and polymers that can absorb and release lithium ions. The positive electrode current collector 13A includes a positive electrode current collector tab 13B as a portion not supported by the positive electrode active material-containing layer.

[0014] 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 (not shown) supported on the surface of the negative electrode current collector 14A. The negative electrode current collector 14A is, but is not limited to, for example, an aluminum foil, an aluminum alloy foil, or a copper foil, and has a thickness of about 10 μm to 20 μm. The negative electrode active material-containing layer includes a negative electrode active material, and may optionally include a binder and a conductive agent. Examples of the negative electrode active material include, but are not limited to, metal oxides, metal sulfides, metal nitrides, and carbon materials that can absorb and release lithium ions. The negative electrode current collector 14A includes a negative electrode current collector tab 14B as a portion where the negative electrode active material-containing layer is not supported.

[0015] In the electrode group 2, a length direction (direction indicated by arrows X3 and X4), a width direction (direction indicated by arrows Y3 and Y4) intersecting (perpendicular or approximately perpendicular) to the length direction, and a thickness direction (direction indicated by arrows Z3 and Z4) intersecting both the length direction and the width direction are defined. In the electrode group 2, the dimension in the thickness direction is smaller than the dimensions in the length direction and the width direction, respectively. Therefore, the electrode group 2 is formed in a flat shape. In the electrode group 2, the positive electrode current collector tab 13B protrudes toward one side in the length direction relative to the negative electrode 14 and the separator. In addition, the negative electrode current collector tab 14B protrudes toward the opposite side from the side where the positive electrode current collector tab 13B protrudes, in the length direction, relative to the positive electrode 13 and the separator. In the electrode group 2 of this embodiment, the positive electrode 13, the negative electrode 14, and the separator are wound around a winding axis C, with the separator sandwiched between the positive electrode active material-containing layer and the negative electrode active material-containing layer. The winding axis C is along the longitudinal direction of the electrode group 2.

[0016] In this embodiment, the electrode group 2 is disposed in the internal cavity 8 with the length direction of the electrode group 2 coinciding or approximately coinciding with the lateral direction of the battery 1 (external container 3) and the width direction of the electrode group 2 coinciding or approximately coinciding with the height direction of the battery 1. In the battery 1, the thickness direction of the electrode group 2 coinciding or approximately coinciding with the depth direction of the battery 1. In the internal cavity 8 of the external container 3, the positive electrode current collecting tab 13B protrudes toward one side in the lateral direction of the battery 1 relative to the negative electrode 14 and the separator. In addition, the negative electrode current collecting tab 14B protrudes toward the side opposite to the side from which the positive electrode current collecting tab 13B protrudes, in the lateral direction of the battery 1, relative to the positive electrode 13 and the separator.

[0017] In addition, in the internal cavity 8, the electrode group 2 is retained (impregnated) with an electrolytic solution (not shown). The electrolytic solution may be a non-aqueous electrolytic solution in which an electrolyte is dissolved in an organic solvent, or may be an aqueous electrolytic solution such as an aqueous solution. Instead of the electrolytic solution, a gel electrolyte or a solid electrolyte may be used. When a solid electrolyte is used as the electrolyte, the solid electrolyte is interposed between the positive electrode 13 and the negative electrode 14 in the electrode group 2, instead of a separator. In this case, the positive electrode 13 is electrically insulated from the negative electrode 14 by the solid electrolyte.

[0018] In the battery 1, a pair of terminals 16 are attached to the outer surface (upper surface) of the cover member 5. The terminals 16 are made of a conductive material such as metal. One of the terminals 16 is a positive terminal of the battery 1, and the other of the terminals 16 is a negative terminal of the battery 1. The cover member 5 is also provided with a pair of through holes 17, which penetrate the cover member 5 in the height direction of the battery 1. An insulating member 18 is provided between each of the terminals 16 and the cover member 5. An insulating gasket 19 is also disposed in each of the through holes 17. Each of the terminals 16 is electrically insulated from the cover member 5 and the outer container 3 by the insulating member 18 and the insulating gasket 19.

[0019] Since a pair of terminals 16 are provided as described above, each of the terminals 16 is disposed offset from the electrode group 2 on one side in the height direction of the battery 1 (width direction of the electrode group 2). Each of the terminals 16 is disposed on the side of the electrode group 2 where the lid member 5 is located in the height direction of the battery 1, and faces the electrode group 2 from one side in the height direction of the battery 1. Therefore, the negative electrode terminal, which is one of the terminals 16, is disposed offset from the electrode group 2 toward the side where the positive electrode terminal, which is the other one of the terminals 16, is located. In addition, the pair of terminals 16 are disposed apart from each other in the lateral direction of the battery 1 (length direction of the electrode group 2). The negative electrode terminal is disposed away from the positive electrode terminal on the side where the negative electrode current collecting tab 14B protrudes.

[0020] A pair of leads 20 are disposed in the internal cavity 8 of the outer container 3. The positive electrode current collecting tab 13B of the electrode group 2 is electrically connected to a positive electrode terminal, which is one of the terminals 16, via a positive electrode side lead, which is one of the leads 20. The negative electrode current collecting tab 14B of the electrode group 2 is electrically connected to a negative electrode terminal, which is one of the terminals 16, via a negative electrode side lead, which is one of the leads 20. Therefore, each of the terminals 16 is electrically connected to the electrode group 2 via a corresponding one of the leads 20. Each of the leads 20 is formed of a conductive material such as a metal. Examples of conductive materials for forming the leads 20 include aluminum, stainless steel, copper, and iron.

[0021] In addition, a pair of insulating guards 21 and an electrode group presser 23 are disposed in the internal cavity 8 of the outer casing 3. Each of the insulating guards 21 is formed from an electrically insulating material. The positive electrode side lead, which is one of the leads 20, and the positive electrode current collector tab 13B are prevented from contacting the outer casing 3 by the corresponding one of the insulating guards 21, and are electrically insulated from the outer casing 3. In addition, the negative electrode side lead, which is one of the leads 20, and the negative electrode current collector tab 14B are prevented from contacting the outer casing 3 by the corresponding one of the insulating guards 21, and are electrically insulated from the outer casing 3. Each of the insulating guards 21 is fixed to the electrode group 2 by an insulating tape 25. The insulating tape 25 is formed from an electrically insulating material.

[0022] In addition, the electrode group presser 23 is disposed between the electrode group 2 and the lid member 5 in the height direction of the battery 1. The electrode group presser (internal insulating member) 23 is formed from an electrically insulating material. The electrode group presser 23 prevents the positive electrode current collector tab 13B, the negative electrode current collector tab 14B, and the pair of leads 20 from contacting the lid member 5, and thus electrically insulates them from the lid member 5.

[0023] 1 and 2, a gas release valve 26 and a liquid filling port 27 are formed in the cover member 5. Then, a sealing plate 28 that closes the liquid filling port 27 is welded to the outer surface of the cover member 5. Note that the gas release valve 26, the liquid filling port 27, etc. do not necessarily have to be provided in the battery 1.

[0024] Fig. 3 shows the configuration of the lead 20, and Figs. 4 and 5 show the electrical connection structure between the electrode group 2 and each of the terminals 16 via a corresponding one of the leads 20. Figs. 3 and 4 show perspective views, and in Fig. 4, the outer container 3, the lid member 5, the electrode group presser 23, etc. are omitted. Fig. 5 shows a cross section perpendicular or approximately perpendicular to the lateral direction of the battery 1 (the length direction of the electrode group 2), and the outer container 3 and the insulating guard 21, etc. are omitted. As shown in Figs. 2 to 5, etc., each of the leads 20 has a top plate portion 31 and a leg portion 32.

[0025] In the top plate portion 31, a length direction (direction indicated by arrows X5 and X6), a plate width direction (direction indicated by arrows Z5 and Z6) intersecting (perpendicular or approximately perpendicular) to the length direction, and a plate thickness direction (direction indicated by arrows Y5 and Y6) intersecting (perpendicular or approximately perpendicular) to both the length direction and the plate width direction are defined. The top plate portion 31 has extension ends E1 and E2, and extends in the length direction from the extension end E1 to the extension end E2. In addition, in the top plate portion 31, a through hole 33 is formed between the extension ends E1 and E2 in the length direction, and the through hole 33 penetrates the top plate portion 31 in the plate thickness direction.

[0026] Further, each lead 20 has only one leg 32. The leg 32 is connected to an extended end E2 of the top plate portion 31. The leg 32 is bent relative to the top plate portion 31 with the connection position to the top plate portion 31 (the extended end E2 of the top plate portion 31) as the bending position. The leg 32 is bent relative to the top plate portion 31 toward one side in the thickness direction of the top plate portion 31 (the arrow Y6 side). Therefore, the leg 32 protrudes relative to the top plate portion 31 toward one side in the thickness direction of the top plate portion 31. The protruding end of the leg 32 from the top plate portion 31 is the distal end E3 of the leg 32 relative to the top plate portion 31. The distal end E3 is the end of the leg 32 opposite to the connection position to the top plate portion 31. The bending line at the bending position of the leg 32 relative to the top plate portion 31 is along the plate width direction of the top plate portion 31. In this embodiment, when the leg portion 32 is bent relative to the top plate portion 31, the bending angle of the leg portion 32 is 90 degrees or approximately 90 degrees.

[0027] The leg 32 is formed in a plate shape. The leg 32 extends straight or approximately straight along the thickness direction of the top plate 31 from a bending position (a connection position to the top plate 31) to a distal end E3 (an end protruding from the top plate 31) to the top plate 31. Therefore, the leg 32 extends without being bent in the length direction and width direction of the top plate 31 between the connection position to the top plate 31 (an extended end E2 of the top plate 31) and the distal end E3 to the top plate 31. In each of the leads 20, the width direction of the leg 32 coincides or approximately coincides with the width direction of the top plate 31, and the thickness direction of the leg 32 intersects (is perpendicular or approximately perpendicular to) both the width direction of the top plate 31 and the thickness direction of the top plate 31. Therefore, the extension direction of the leg 32 from the connection position of the leg 32 to the top plate portion 31 to the distal end E3 of the leg 32 relative to the top plate portion 31, i.e., the length direction of the leg 32, coincides or approximately coincides with the thickness direction of the top plate portion 31.

[0028] In each of the leads 20, the outer surface of the leg 32 is formed of a pair of leg main surfaces 35, 36 and a pair of leg edge surfaces 37, 38. The leg main surface (first leg main surface) 35 faces one side in the plate thickness direction of the leg 32, i.e., one side in the longitudinal direction of the top plate portion 31. The leg main surface (second leg main surface) 36 faces the opposite side to the leg main surface 35 in the plate thickness direction of the leg 32, i.e., in the longitudinal direction of the top plate portion 31. In this embodiment, the leg main surface 35 faces the side where the extended end E1 of the top plate portion 31 is located in the longitudinal direction of the top plate portion 31, and the leg main surface 36 faces the opposite side to the side where the extended end E1 of the top plate portion 31 is located in the longitudinal direction of the top plate portion 31. In this embodiment, each of the leg main surfaces 35, 36 is parallel or approximately parallel to both the thickness direction and the width direction of the top plate portion 31 from the connection position of the leg 32 to the top plate portion 31 to the distal end E3 of the leg 32 with respect to the top plate portion 31. Therefore, each of the leg main surfaces 35, 36 is perpendicular or approximately perpendicular to the length direction of the top plate portion 31 from the connection position of the leg 32 to the top plate portion 31 to the distal end E3 of the leg 32 with respect to the top plate portion 31.

[0029] The leg edge surface (first leg edge surface) 37 is provided at an edge on one side of the leg 32 in the width direction of the leg 32 (width direction of the top plate 31) to relay between the leg main surfaces 35, 36, and is continuously extended from the leg main surface 35 to the leg main surface 36 along the thickness direction of the leg 32 (length direction of the top plate 31). The leg edge surface 37 faces one side of the leg 32 in the width direction. The leg edge surface (second leg edge surface) 38 is provided at an edge on the opposite side of the leg edge surface 37 in the width direction of the leg 32 (width direction of the top plate 31) to relay between the leg main surfaces 35, 36, and is continuously extended from the leg main surface 35 to the leg main surface 36 along the thickness direction of the leg 32 (length direction of the top plate 31). The leg edge surface 38 faces the opposite side of the leg edge surface 37 in the width direction of the leg 32. In this embodiment, each of the leg edge surfaces 37, 38 is parallel or approximately parallel to both the thickness direction and the length direction of the top plate portion 31 from the connection position of the leg 32 to the top plate portion 31 to the distal end E3 of the leg 32 with respect to the top plate portion 31. Therefore, each of the leg edge surfaces 37, 38 is perpendicular or approximately perpendicular to the plate width direction of the top plate portion 31 from the connection position of the leg 32 to the top plate portion 31 to the distal end E3 of the leg 32 with respect to the top plate portion 31.

[0030] FIG. 6 shows the configuration of the electrode group 2 and the current collecting tabs 13B, 14B. In FIG. 6, a cross section perpendicular or approximately perpendicular to the length direction of the electrode group 2 is shown. As shown in FIG. 2, FIG. 4 to FIG. 6, etc., the electrode group 2 has an electrode group end face 41A at one end in the length direction, and an electrode group end face 41B at an end opposite to the electrode group end face 41A in the length direction. The electrode group end faces 41A, 41B face opposite each other in the length direction of the electrode group 2, and each of the electrode group end faces 41A, 41B faces outward in the length direction of the electrode group 2. In the battery 1, each of the electrode group end faces 41A, 41B faces outward in the lateral direction. In addition, the positive electrode current collecting tab 13B protrudes from the electrode group end face 41A toward the side toward which the electrode group end face 41A faces, and the negative electrode current collecting tab 14B protrudes from the electrode group end face 41B toward the side toward which the electrode group end face 41B faces. In the battery 1, each of the current collecting tabs 13B, 14B protrudes laterally outward from a corresponding one of the electrode group end faces 41A, 41B as its base position.

[0031] Each of the current collecting tabs 13B, 14B includes tab extensions 42, 43 and a tab side portion 45. The tab extension (first tab extension) 42 extends along the width direction of the electrode group 2. The tab extension (second tab extension) 43 is formed at a position away from the tab extension 42 in the thickness direction of the electrode group 2, and extends along the width direction of the electrode group 2. Since the tab extensions 42, 43 are formed as described above, a space 46 is formed between the tab extensions 42, 43 in the thickness direction of the electrode group 2. In each of the current collecting tabs 13B, 14B, the tab side portion 45 forms one end (edge) in the width direction of the electrode group 2. One end of each of the tab extensions 42, 43 is connected to the tab side portion 45. The tab side portions 45 relay between the tab extension portions 42, 43, and the tab extension portion 43 is folded back onto the tab extension portion 42 at the tab side portions 45. In this embodiment, the tab extension portion 42 is continuous with the tab extension portion 43 only with the tab side portions 45 therebetween.

[0032] In each of the current collecting tabs 13B and 14B, the space 46 between the tab extensions 42 and 43 opens at an opening 47 toward the opposite side to the tab side portion 45 in the width direction of the electrode group 2. The opening 47 is formed between the distal end E4 of the tab extension 42 relative to the tab side portion 45 and the distal end E5 of the tab extension 43 relative to the tab side portion 45. The tab side portion 45 is adjacent to the space 46 from the opposite side to the opening 47 in the width direction of the electrode group 2, and the space 46 does not open to the opposite side to the opening 47 in the width direction of the electrode group 2. The space 46 formed in each of the current collecting tabs 13B and 14B opens to the outside in the length direction of the electrode group 2. Since the tab extensions 42 and 43 and the tab side portion 45 are formed as described above, in this embodiment, each of the current collecting tabs 13B and 14B is U-shaped or approximately U-shaped when viewed from the outside in the length direction of the electrode group 2.

[0033] In each of the current collecting tabs 13B, 14B, the distal end E5 of the tab extension portion 43 relative to the tab side portion 45 is located farther away from the tab side portion 45 in the width direction of the electrode group 2 than the distal end E4 of the tab extension portion 42 relative to the tab side portion 45. For this reason, the tab extension portion (second tab extension portion) 43 extends to a position farther away from the tab side portion 45 in the width direction of the electrode group 2 than the tab extension portion (first tab extension portion) 42. Therefore, the tab extension portion 43 includes an additional extension portion 48 that extends beyond the tab extension portion 42 (distal end E4) toward the side away from the tab side portion 45.

[0034] In the battery 1, in each of the current collecting tabs 13B, 14B, the tab extensions 42, 43 extend along the height direction, and the tab extension (second tab extension) 43 is formed away from the tab extension (first tab extension) 42 in the depth direction. In addition, in each of the current collecting tabs 13B, 14B, the tab side portion 45 is disposed on the opposite side of the tab extensions 42, 43 from the terminal 16 in the height direction, that is, on the side where the bottom wall 6 is located. Therefore, in each of the current collecting tabs 13B, 14B, the space 46 between the tab extensions 42, 43 opens at the opening 47 toward the side where the terminal 16 is located in the height direction of the battery 1. In each of the current collecting tabs 13B, 14B, the space 46 also opens toward the outside in the lateral direction of the battery 1.

[0035] In the battery 1, in each of the current collecting tabs 13B, 14B, the distal end E5 of the tab extension portion 43 relative to the tab side portion 45 is located closer to the terminal 16 in the height direction than the distal end E4 of the tab extension portion 42 relative to the tab side portion 45. For this reason, the tab extension portion (second tab extension portion) 43 extends to a position closer to the terminal 16 in the height direction of the battery 1 than the tab extension portion (first tab extension portion) 42. Therefore, in the tab extension portion 43, the additional extension portion 48 extends beyond the tab extension portion 42 (distal end E4) toward the side where the terminal 16 is located in the height direction of the battery 1.

[0036] As shown in FIG. 2, FIG. 4, FIG. 5, etc., in the internal cavity 8 of the battery 1, the top plate portion 31 of each of the pair of leads 20 is disposed between the electrode group 2 and the electrode group presser 23 in the height direction of the battery 1, and is sandwiched between the electrode group 2 and the electrode group presser 23. In each of the leads 20, the length direction of the top plate portion 31 coincides or approximately coincides with the lateral direction of the battery 1 (the length direction of the electrode group 2), and the plate width direction of the top plate portion 31 coincides or approximately coincides with the depth direction of the battery 1 (the thickness direction of the electrode group 2). In each of the leads 20, the plate thickness direction of the top plate portion 31 coincides or approximately coincides with the height direction of the battery 1 (the width direction of the electrode group 2). In each of the leads 20, the extension end E1 and the through hole 33 in the top plate portion 31 are located inward in the lateral direction of the battery 1 compared to the extension end E2 (the bending position of the leg portion 32 relative to the top plate portion 31). For this reason, the top plate portions 31 of each lead 20 extend outward in the lateral direction of the battery 1 from the extended end E1 to the extended end E2. In the battery 1, a corresponding one of the terminals 16, i.e., a corresponding one of the positive terminal and the negative terminal, is connected to each of the top plate portions 31 of a pair of leads 20. In each of the leads 20, a corresponding one of the terminals 16 is inserted into a through hole 33 in the top plate portion 31. Then, the corresponding one of the terminals 16 is connected to each of the leads 20 by crimping or the like at the through hole 33.

[0037] Furthermore, in the internal cavity 8 of the battery 1, the leg 32 of each of the pair of leads 20 is disposed between a corresponding one of the side walls 11 and the electrode group 2 in the lateral direction of the battery 1. In each of the leads 20, the plate width direction of the leg 32 coincides or approximately coincides with the depth direction of the battery 1 (thickness direction of the electrode group 2), and the plate thickness direction of the leg 32 coincides or approximately coincides with the lateral direction of the battery 1 (length direction of the electrode group 2). In each of the leads 20, the leg 32 is disposed on the outside of the through hole 33, i.e., the connection position of a corresponding one of the terminals 16, in the lateral direction of the battery 1.

[0038] Moreover, in each of the leads 20, the leg 32 is bent relative to the top plate 31 toward the side where the electrode group 2 and the bottom wall 6 are located in the height direction of the battery 1. The bending line of the leg 32 relative to the top plate 31 is along the depth direction of the battery 1. Moreover, in each of the leads 20, the leg 32 extends straight or approximately straight along the height direction of the battery 1 from the bending position relative to the top plate 31 (extension end E2 of the top plate 31) to the distal end E3 relative to the top plate 31. In each of the current collecting tabs 13B, 14B, one of the corresponding leg portions 32 of the lead 20 is inserted from an opening 47 into a space 46 between the tab extension portions 42, 43. Therefore, each leg 32 of the lead 20 is inserted between the tab extensions 42, 43 of the corresponding current collecting tabs 13B, 14B from the side where the terminal 16 is located in the height direction of the battery 1.

[0039] In each leg 32 of the lead 20, the leg main surface (first leg main surface) 35 faces inward in the lateral direction of the battery 1 and faces one of the corresponding electrode group end faces 41A, 41B. In addition, the leg main surface (second leg main surface) 36 faces outward in the lateral direction of the battery 1. In each lead 20, each of the leg main surfaces 35, 36 of the leg 32 is formed parallel or approximately parallel to the corresponding one of the electrode group end faces 41A, 41B from the connection position of the leg 32 to the top plate portion 31 to the distal end E3 of the leg 32 relative to the top plate portion 31, and is parallel or approximately parallel to both the height direction of the battery 1 and the depth direction of the battery 1. Furthermore, in each leg 32 of the lead 20, the leg edge surface (first leg edge surface) 37 faces one side in the depth direction of the battery 1, and the leg edge surface (second leg edge surface) 38 faces the opposite side to the leg edge surface 37 in the depth direction of the battery 1. In each lead 20, each of the leg edge surfaces 37, 38 of the leg 32 is parallel or approximately parallel to both the height direction of the battery 1 and the lateral direction of the battery 1 from the connection position of the leg 32 to the top plate portion 31 to the distal end E3 of the leg 32 relative to the top plate portion 31.

[0040] As shown in Figs. 2, 4, 5, etc., two pairs of clips (backup leads) 51, 52 are disposed in the internal cavity 8 of the outer container 3. In each of the current collecting tabs 13B, 14B, a plurality of strip-shaped portions are bundled in each of the tab extensions 42, 43. In each of the tab extensions (first tab extensions) 42 of the current collecting tabs 13B, 14B, the bundled plurality of strip-shaped portions are clamped by one corresponding one of a pair of clips 51. In each of the tab extensions (second tab extensions) 43 of the current collecting tabs 13B, 14B, the bundled plurality of strip-shaped portions are clamped by one corresponding one of a pair of clips 52. In the tab extensions 43, the additional extension portion 48 is clamped by the clip 52.

[0041] Furthermore, in each of the leads 20, the leg 32 is joined (connected) to a corresponding one of the current collecting tabs 13B, 14B. In this embodiment, in each of the current collecting tabs 13B, 14B, a leg edge surface (first leg edge surface) 37 of the leg 32 of the corresponding one of the leads 20 is joined to a tab extension portion (first tab extension portion) 42. The leg edge surface 37 of the leg 32 is joined to the tab extension portion 42 with the clip 51 interposed therebetween, and is joined to the tab extension portion 42 from the side where the tab extension portion 43 is located in the depth direction of the battery 1.

[0042] In each of the current collecting tabs 13B, 14B, a leg edge surface (second leg edge surface) 38 of a corresponding one of the legs 32 of the lead 20 is joined to an additional extension portion 48 of a tab extension portion (second tab extension portion) 43. The leg edge surface 38 of the leg 32 is joined to the tab extension portion 43 via a clip 52, and is joined to the tab extension portion 43 from the side where the tab extension portion 42 is located in the depth direction of the battery 1. In this embodiment, since the leg edge surface 38 is joined to the additional extension portion 48 in the tab extension portion 43, the joining position (second joining position) of the leg edge surface 38 to the tab extension portion 43 is formed at a position closer to the terminal 16 in the height direction of the battery 1 than the joining position (first joining position) of the leg edge surface 37 to the tab extension portion 42.

[0043] Here, the manufacture of the battery 1 will be described. In the manufacture of the battery 1, the electrode group 2 is formed by winding the positive electrode 13, the negative electrode 14, etc. around the winding axis C. At this time, the current collecting tabs 13B, 14B are formed in the electrode group 2 in a state of protruding outward in the length direction of the electrode group 2. The current collecting tabs 13B, 14B are formed in a state of protruding in opposite directions to each other. In the formation of each of the current collecting tabs 13B, 14B, a part of the protruding portion outward in the length direction in the electrode group 2 is cut. For example, in each of the protruding portions outward in the length direction in the electrode group 2, a current collecting tab (corresponding one of 13B, 14B) having the tab extension portions 42, 43 and the tab side portion 45 is formed by cutting the portion 53 shown by the dashed line in FIG. 6.

[0044] In each of the current collecting tabs 13B and 14B before the portion 53 is cut, the portion 53 forms an end opposite to the tab side portion 45 in the width direction of the electrode group 2. The portion 53 is adjacent to the space 46 between the tab extension portions 42 and 43 from the opposite side to the tab side portion 45. In each of the protruding portions (current collecting tabs 13B and 14B), before the portion 53 is cut, the tab extension portion 42 is continuous with the tab extension portion 43 with the tab side portion 45 interposed therebetween, and is also continuous with the tab extension portion 43 with the portion 53 interposed therebetween. In each of the current collecting tabs 13B and 14B, an opening 47 of the space 46 is formed by cutting the portion 53, and the space 46 opens at the opening 47 to the opposite side to the tab side portion 45 in the width direction of the electrode group 2. In the present embodiment, the portion 53 is cut in a state in which an additional extension portion 48 of the tab extension portion 43 is formed.

[0045] In addition, in manufacturing the battery 1, the pair of leads 20 described above are formed. At this time, in each of the leads 20, the top plate portion 31 and the leg portion 32 are formed in the configuration described above. Therefore, in each of the leads 20, the leg portion 32 is bent relative to the top plate portion 31 to one side in the plate thickness direction of the top plate portion 31 with the bending line aligned along the plate width direction of the top plate portion 31. The leg portion 32 is formed straight or approximately straight from the bending position relative to the top plate portion 31 to the distal end E3 relative to the top plate portion 31.

[0046] In manufacturing the battery 1, a pair of terminals 16 are attached to the outer surface of the cover member 5, and one corresponding top plate portion 31 of the lead 20 is connected to each of the terminals 16. Then, with one corresponding top plate portion 31 of the lead 20 connected to each of the terminals 16, the terminals 16 and the top plate portion 31 are disposed at a position offset from the electrode group 2 in the width direction of the electrode group 2.

[0047] Then, in each of the current collecting tabs 13B, 14B, the corresponding one of the leg portions 32 of the lead 20 is inserted into the space 46 between the tab extension portions 42, 43 from the side where the terminal 16 is located in the width direction of the electrode group 2, that is, from the opening 47. As a result, each of the leg portions 32 of the lead 20 is in a state of being along the width direction of the electrode group 2 from the bending position with respect to the top plate portion 31 to the distal end E3 with respect to the top plate portion 31. In each of the leg portions 32 of the lead 20, the leg main surface 35 faces the corresponding one of the electrode group end surfaces 41A, 41B, and the leg main surface 36 faces outward in the length direction of the electrode group 2. In each of the leg portions 32 of the lead 20, the leg edge surface 37 faces one side in the thickness direction of the electrode group 2, and the leg edge surface 38 faces the opposite side to the leg edge surface 37 in the thickness direction of the electrode group 2.

[0048] Then, in each of the current collecting tabs 13B and 14B, the leg edge surface 37 of the corresponding one leg 32 of the lead 20 is joined to the tab extension portion 42 by ultrasonic welding or the like. At this time, with the tab extension portion 42 held by the clip 51, the leg edge surface 37 of the leg 32 is joined to the tab extension portion 42 from the side where the tab extension portion 43 is located in the thickness direction of the electrode group 2. Also, in each of the current collecting tabs 13B and 14B, the leg edge surface 38 of the corresponding one leg 32 of the lead 20 is joined to the additional extension portion 48 of the tab extension portion 43 by ultrasonic welding or the like. At this time, with the tab extension portion 43 held by the clip 52, the leg edge surface 38 of the leg 32 is joined to the tab extension portion 43 from the side where the tab extension portion 42 is located in the thickness direction of the electrode group 2. One leg 32 of the lead 20 is joined to each of the current collecting tabs 13B, 14B, so that the electrode group 2 is electrically connected to each of the terminals 16.

[0049] In manufacturing the battery 1, an assembly including the electrode group 2, the lead 20, the cover member 5, and the terminal 16 is inserted into the internal cavity 8 of the outer container 3, and the electrode group 2 and the lead 20 are stored in the internal cavity 8. Then, the cover member 5 is attached to the peripheral wall 7 of the outer container 3 by welding or the like. As a result, the opening of the internal cavity 8 is closed by the cover member 5.

[0050] In the lead 20 of this embodiment, the leg 32 is bent relative to the top plate 31 with the bending line at the bending position relative to the top plate 31 aligned along the plate width direction of the top plate 31. The plate width direction of the leg 32 coincides or approximately coincides with the plate width direction of the top plate 31. Therefore, unlike a configuration in which the leg is bent relative to the top plate 31 with the bending line aligned along the length direction of the top plate 31 (the extension direction from the extended end E1 to the extended end E2), there is no need to form a notch or the like at the connection position of the leg 32 and its vicinity in the top plate 31. This ensures a large cross-sectional area of ​​the top plate 31 at the portion where the leg 32 is connected and its vicinity, i.e., at the extended end E2 and its vicinity.

[0051] In this embodiment, the leg 32 of the lead 20 extends straight or approximately straight along the height direction of the battery 1 (the plate thickness direction of the top plate 31) from the bending position relative to the top plate 31 to the distal end E3 relative to the top plate 31. That is, the leg 32 is not bent in the lateral direction of the battery 1 (the length direction of the top plate 31) or in the depth direction of the battery 1 (the plate width direction of the top plate 31) between the connection position to the top plate 31 and the distal end E3 relative to the top plate 31. Therefore, in each of the leads 20, the extension length from the joining position (connection position) to the corresponding one of the current collecting tabs 13B, 14B to the connection position (through hole 33) of the corresponding one of the terminals 16 is ensured to be short. That is, the lead 20 ensures that the path length of the electrical path between the electrode group 2 and the terminal 16 is short.

[0052] As described above, in the lead 20 of this embodiment, the cross-sectional area of ​​the top plate portion 31 is ensured to be large, and the path length of the electrical path between the electrode group 2 and the terminal 16 is ensured to be short. This ensures low electrical resistance of the lead 20. The low electrical resistance of the lead 20, which serves as the electrical path between the electrode group 2 and the terminal 16, realizes high output of the battery 1.

[0053] In each of the leads 20 of this embodiment, on the outer surface of the leg 32, the leg edge surface 37 faces one side in the width direction of the top plate portion 31, and the leg edge surface 38 faces the opposite side to the leg edge surface 37 in the width direction of the top plate portion 31. Therefore, even if the leg 32 of each of the leads 20 is bent relative to the top plate portion 31 as described above, the leg edge surface 37 can be easily joined to the corresponding one of the tab extension portions 42 of the current collecting tabs 13B, 14B from one side in the thickness direction of the electrode group 2. Similarly, in each of the leads 20, the leg edge surface 38 can be easily joined to the corresponding one of the tab extension portions 43 of the current collecting tabs 13B, 14B from the side where the tab extension portion 42 is located in the thickness direction of the electrode group 2. Therefore, in this embodiment, even if the leg 32 is bent relative to the top plate portion 31 as described above, the workability of joining the corresponding one of the leads 20 to each of the current collecting tabs 13B, 14B is ensured.

[0054] Furthermore, in each of the current collecting tabs 13B, 14B of the present embodiment, the space 46 between the tab extension portions 42, 43 opens at an opening 47 toward the opposite side to the tab side portion 45 in the width direction of the electrode group 2. Therefore, even if each of the leads 20 has a configuration in which the leg portions 32 extend straight or approximately straight as described above, the leg portions 32 can be easily inserted from the opening 47 into the space 46 formed in the corresponding one of the current collecting tabs 13B, 14B. Since each of the leg portions 32 of the leads 20 can be easily inserted into the space 46 in the corresponding one of the current collecting tabs 13B, 14B, the ease of insertion of the leg portions 32 of the leads 20 into the space 46 in the corresponding one of the current collecting tabs 13B, 14B further improves the operability of joining each of the leads 20 to the corresponding one of the current collecting tabs 13B, 14B.

[0055] Furthermore, in the present embodiment, in forming the electrode group 2, openings 47 of spaces 46 are formed by cutting portions 53 from each of current collecting tabs 13B, 14B (portions protruding outward in the longitudinal direction of the electrode group 2). Therefore, even in a configuration in which openings 47 of spaces 46 are formed in each of current collecting tabs 13B, 14B, the electrode group 2 can be formed without any or almost no increase in effort or the like.

[0056] In addition, in each of the current collecting tabs 13B, 14B of this embodiment, the additional extension portion 48 of the tab extension portion 43 extends beyond the tab extension portion 42 (distal end E4) toward the side where the terminal 16 is located in the height direction of the battery 1 (the side away from the tab side portion 45). The leg edge surface 38 of the leg portion 32 of the lead 20 is joined to the additional extension portion 48 of the tab extension portion 43. Therefore, compared with the joining position of the leg edge surface 37 to the tab extension portion 42, the joining position of the leg edge surface 38 to the tab extension portion 43 is formed at a position closer to the terminal 16 in the height direction of the battery 1. This ensures the ease of joining one of the corresponding leads 20 to each of the current collecting tabs 13B, 14B, even when one of the corresponding legs 32 of the lead 20 is joined to each of the current collecting tabs 13B, 14B at two joining positions.

[0057] (Modification) In the first modified example shown in FIG. 7, the distal end E5 of the tab extension 43 relative to the tab side portion 45 is not shifted or is hardly shifted in the height direction of the battery 1 (width direction of the electrode group 2) with respect to the distal end E4 of the tab extension 42 relative to the tab side portion 45. Therefore, the additional extension portion 48 is not formed in the tab extension 43. The joining position (second joining position) of the leg edge surface (second leg edge surface) 38 to the tab extension (second tab extension) 43 is not shifted or is hardly shifted in the height direction of the battery 1 with respect to the joining position (first joining position) of the leg edge surface (first leg edge surface) 37 to the tab extension (first tab extension) 42. In this modified example, in each of the current collecting tabs 13B and 14B, the space 46 opens at an opening 47 on the opposite side to the tab side portion 45 in the width direction of the electrode group 2. In forming each of the current collecting tabs 13B and 14B, a part of the outward protruding portion in the longitudinal direction of the electrode group 2 (part 53 indicated by the dashed line in FIG. 7) is cut off, and an opening 47 is formed.

[0058] In addition, in one modified example, similar to the first modified example, the distal end E5 of the tab extension portion 43 is not misaligned or is barely misaligned in the height direction of the battery 1 (the width direction of the electrode group 2) with respect to the distal end E4 of the tab extension portion 42. However, in this modified example, only the leg edge surface 37 is joined to the tab extension portion 42, and the leg edge surface 38 is not joined to the tab extension portion 43.

[0059] In the second modification of FIG. 8, the current collecting tabs 13B, 14B are not provided with the tab extension 43. Therefore, the space 46 and the opening 47 are not formed in the current collecting tabs 13B, 14B. In this modification, the current collecting tabs 13B, 14B are also formed with the tab extension 42 and the tab side portion 45. The leg edge surface 37 of each leg 32 of the lead 20 is joined to the corresponding one of the tab extensions 42 of the current collecting tabs 13B, 14B from one side in the depth direction of the battery 1 (thickness direction of the electrode group 2). In this modification, when forming each of the current collecting tabs 13B, 14B, a part of the protruding portion outward in the length direction of the electrode group 2 (portion 53 indicated by the dashed line in FIG. 8) is cut. Before portion 53 is cut, in each of current collecting tabs 13B and 14B, the end of tab extension portion 42 opposite tab side portion 45 is connected to portion 53.

[0060] As a modification of the first embodiment, two clips (backup leads) may be attached to at least one of the tab extensions 42, 43 of each of the current collecting tabs 13B, 14B. For example, in a third modification of FIG. 9, two clips, a first clip (first backup lead) 51A and a second clip (second backup lead) 51B, are attached to the tab extension 42. The clips 51A, 51B are attached to the tab extension 42 at positions spaced apart from each other in the width direction of the electrode group 2. In this modification, the tab extension 42 is joined to the leg edge surface 37 of the leg 32 of the lead 20 via the first clip 51A, and is joined to the leg edge surface 37 of the leg 32 of the lead 20 via the second clip 51B at a position spaced apart from the first clip 51A in the height direction of the battery 1. That is, the tab extension 42 is joined to the leg edge surface 37 of the leg 32 of the lead 20 at two different locations.

[0061] In a modified example, the electrode group 2 may have a stack structure in which a plurality of positive electrodes 13 and a plurality of negative electrodes 14 are alternately stacked, instead of a wound structure. In this case, the positive electrodes 13 and the negative electrodes 14 in the electrode group 2 are electrically insulated from each other by a separator or the like. When the electrode group 2 has a stack structure, the openings 47 of the above-mentioned space 46 can be formed without cutting a portion of each of the portions of the electrode group 2 that protrude outward in the length direction. That is, in each of the portions (current collecting tabs 13B, 14B) that protrude outward in the length direction of the electrode group 2, the leg edge surface 37 of the leg portion 32 that extends straight or approximately straight can be joined to the tab extension portion 42 without cutting a portion.

[0062] In any of the above-mentioned modified examples, similar to the first embodiment, the lead 20 includes a top plate 31 and a leg 32 bent relative to the top plate 31 toward one side in the plate thickness direction of the top plate 31. The plate width direction of the leg 32 coincides or substantially coincides with the plate width direction of the top plate 31. Therefore, similar to the first embodiment, a large cross-sectional area of ​​the top plate 31 is ensured at the portion where the leg 32 is connected and its vicinity, i.e., at the extended end E2 and its vicinity. In any of the above-mentioned modified examples, similar to the first embodiment, the leg 32 of the lead 20 extends straight or substantially straight along the height direction of the battery 1 (plate thickness direction of the top plate 31) from the bending position relative to the top plate 31 to the distal end E3 relative to the top plate 31. This ensures that each lead 20 has a short extension length from the joining position to the corresponding one of current collecting tabs 13B, 14B to the connection position (through hole 33) to the corresponding one of terminals 16. Therefore, in any of the modified examples described above, the electrical resistance of the lead 20 is kept low, and high output of the battery 1 is achieved.

[0063] It is not necessary that both the positive electrode side electrical connection structure from the electrode group 2 to the positive electrode terminal with the positive electrode current collecting tab 13B and the positive electrode side lead interposed therebetween, and the negative electrode side electrical connection structure from the electrode group 2 to the negative electrode with the negative electrode current collecting tab 14B and the negative electrode side lead interposed therebetween, have the same configuration as any of the above-mentioned embodiments and modified examples, etc. In other words, it is sufficient that at least one of the positive electrode side connection structure and the negative electrode side connection structure has the same configuration as any of the above-mentioned embodiments and modified examples, etc.

[0064] According to at least one of these embodiments or examples, the leg of the lead is bent relative to the top plate toward the side where the electrode group is located in the height direction of the battery, and the bending line of the leg relative to the top plate is along the depth direction of the battery. The leg of the lead extends straight along the height direction of the battery from the bending position relative to the top plate to the distal end relative to the top plate. The leg edge surface of the outer surface of the leg faces one side in the depth direction of the battery and is joined to the current collecting tab. This ensures low electrical resistance of the lead, and a battery that realizes high output can be provided.

[0065] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. The following are additional notes. [1] An electrode group including a positive electrode and a negative electrode; a current collecting tab protruding laterally outward from the electrode group; a terminal disposed offset from the electrode group in a height direction intersecting the lateral direction; a lead electrically connecting the electrode group and the terminal; Equipped with The lead is A top plate portion to which the terminal is connected; a leg portion that is bent with respect to the top plate portion toward a side where the electrode group is located in the height direction, and a bending line with respect to the top plate portion is formed along a depth direction that intersects both the lateral direction and the height direction, the leg portion extending straight along the height direction from a bending position with respect to the top plate portion to a distal end with respect to the top plate portion; a first leg edge surface that faces one side in the depth direction on an outer surface of the leg and is joined to the current collecting tab; Equipped with a battery. [2] The current collecting tab is a first tab extension portion extending along the height direction; a second tab extension portion that is formed apart from the first tab extension portion in the depth direction and extends along the height direction; Equipped with the leg portion of the lead is inserted between the first tab extension portion and the second tab extension portion from a side where the terminal is located in the height direction, The first leg edge surface of the leg portion is joined to the first tab extension portion from a side where the second tab extension portion is located in the depth direction. [1] Battery. [3] The leg portion of the lead has a second leg edge surface facing the opposite side to the first leg edge surface on the outer surface, The second leg edge surface is joined to the second tab extension portion from a side where the first tab extension portion is located in the depth direction. [2] Battery. [4] The second tab extension portion extends to a position closer to the terminal in the height direction than the first tab extension portion, a joining position of the second leg edge surface to the second tab extension portion is formed at a position closer to the terminal in the height direction than a joining position of the first leg edge surface to the first tab extension portion; [3] Battery. [5] The electrode group has an electrode group end surface facing outward in the lateral direction, the current collecting tab protrudes from the electrode group end surface outward in the lateral direction, The legs of the leads include: a first leg main surface that faces the electrode group end surface on the outer surface and is formed parallel to the electrode group end surface from the bending position of the leg portion relative to the top plate portion to the distal end of the leg portion relative to the top plate portion; a second leg main surface facing the opposite side to the first leg main surface on the outer surface and formed parallel to the electrode group end surface from the bending position of the leg with respect to the top plate portion to the distal end of the leg with respect to the top plate portion; Equipped with The first leg edge surface connects the first leg main surface and the second leg main surface at an edge on one side of the leg portion. Any one of the batteries [1] to [4]. [6] The current collecting tab is at least one of a positive electrode current collecting tab protruding from the electrode group to one side in the lateral direction and a negative electrode current collecting tab protruding from the electrode group to a side opposite to the side from which the positive electrode current collecting tab protrudes, the terminal is at least one of a positive electrode terminal disposed offset from the electrode group on one side in the height direction, and a negative electrode terminal offset from the electrode group in the height direction toward the side where the positive electrode terminal is located and disposed away from the positive electrode terminal in the lateral direction toward a side where the negative electrode current collecting tab protrudes, the lead is at least one of a positive electrode side lead that electrically connects between the positive electrode current collecting tab and the positive electrode terminal, and a negative electrode side lead that electrically connects between the negative electrode current collecting tab and the negative electrode terminal; Any one of the batteries [1] through [5]. [7] forming an electrode group from a positive electrode and a negative electrode, and forming a current collecting tab on the electrode group so as to protrude outward in a longitudinal direction of the electrode group; forming a lead by bending the leg portion toward one side of the top plate portion in a thickness direction of the top plate portion with a bending line along a width direction of the top plate portion, and forming the leg portion straight from a bending position relative to the top plate portion to a distal end relative to the top plate portion; connecting the top plate portion of the lead to a terminal; the terminal connected to the top plate portion is disposed at a position offset from the electrode group in a width direction of the electrode group that intersects with the length direction of the electrode group, and the lead is disposed in a state in which the leg portion is aligned along the width direction of the electrode group from the bending position with respect to the top plate portion to the distal end with respect to the top plate portion; a leg edge surface of an outer surface of the leg portion arranged along the width direction of the electrode group, the leg edge surface facing one side in a thickness direction of the electrode group intersecting both the length direction and the width direction of the electrode group, is joined to the current collecting tab to electrically connect the electrode group and the terminal; A method for manufacturing a battery comprising the steps of: [Explanation of symbols]

[0066] 1...battery, 2...electrode group, 13...positive electrode, 13B...current collecting tab (positive electrode current collecting tab), 14...negative electrode, 14B...current collecting tab (negative electrode current collecting tab), 16...terminal, 20...lead, 31...top plate portion, 32...leg portion, 35...leg main surface (first leg main surface), 36...leg main surface (second leg main surface), 37...leg edge surface (first leg edge surface), 38...leg edge surface (second leg edge surface), 41A, 41B...electrode group end surface, 42...tab extension portion (first tab extension portion), 43...tab extension portion (second tab extension portion).

Claims

1. an electrode group formed integrally with a positive electrode and a negative electrode; a current collecting tab protruding laterally outward from the electrode group; a terminal disposed offset from the electrode group in a height direction intersecting the lateral direction; a lead electrically connecting the electrode group and the terminal; Equipped with The current collecting tab is a first tab extension portion extending along the height direction; a second tab extension portion that is formed apart from the first tab extension portion in a depth direction that intersects both the lateral direction and the height direction and extends along the height direction, the second tab extension portion being formed integrally with the first tab extension portion on the integrated electrode group; Equipped with the second tab extension portion includes an additional extension portion extending beyond the first tab extension portion toward a side where the terminal is located in the height direction, The lead is A top plate portion to which the terminal is connected; a leg portion that is bent with respect to the top plate portion toward a side where the electrode group is located in the height direction and has a bending line with respect to the top plate portion along the depth direction, the leg portion extending straight along the height direction from a bending position with respect to the top plate portion to a distal end with respect to the top plate portion; Equipped with the leg portion of the lead is inserted between the first tab extension portion and the second tab extension portion from a side where the terminal is located in the height direction, The leg portion is a first leg edge surface that faces one side in the depth direction on an outer surface of the leg portion and is joined to the first tab extension portion from a side where the second tab extension portion is located in the depth direction; a second leg edge surface that faces the opposite side to the first leg edge surface on the outer surface of the leg portion and is joined to the second tab extension portion by the additional extension portion from the side where the first tab extension portion is located in the depth direction; Equipped with a battery.

2. a first clip that clamps the first tab extension; a second clip that clamps the second tab extension portion with the additional extension portion; Further comprising: The first leg edge surface of the leg portion is joined to the first tab extension portion with the first clip therebetween, The second leg edge surface of the leg portion is joined to the additional extension portion of the second tab extension portion with the second clip interposed therebetween.

2. The battery of claim 1.

3. the electrode group includes an electrode group end surface facing outward in the lateral direction, the current collecting tab protrudes from the electrode group end surface outward in the lateral direction, The legs of the leads include: a first leg main surface that faces the electrode group end surface on the outer surface and is formed parallel to the electrode group end surface from the bending position of the leg portion relative to the top plate portion to the distal end of the leg portion relative to the top plate portion; a second leg main surface facing the opposite side to the first leg main surface on the outer surface and formed parallel to the electrode group end surface from the bending position of the leg with respect to the top plate portion to the distal end of the leg with respect to the top plate portion; Equipped with The first leg edge surface connects the first leg main surface and the second leg main surface at an edge on one side of the leg portion.

3. The battery of claim 1 or 2.

4. the current collecting tab is at least one of a positive electrode current collecting tab protruding from the electrode group to one side in the lateral direction and a negative electrode current collecting tab protruding from the electrode group to a side opposite to a side from which the positive electrode current collecting tab protrudes, the terminal is at least one of a positive electrode terminal disposed offset from the electrode group on one side in the height direction, and a negative electrode terminal offset from the electrode group in the height direction toward the side where the positive electrode terminal is located and disposed away from the positive electrode terminal in the lateral direction toward a side where the negative electrode current collecting tab protrudes, the lead is at least one of a positive electrode side lead that electrically connects between the positive electrode current collecting tab and the positive electrode terminal, and a negative electrode side lead that electrically connects between the negative electrode current collecting tab and the negative electrode terminal; The battery of any one of claims 1 to 3.

5. forming an electrode group integrally from a positive electrode and a negative electrode, and forming a current collecting tab on the electrode group so as to protrude outward in a longitudinal direction of the electrode group; forming a first tab extension portion in the current collecting tab along a width direction of the electrode group intersecting the length direction, and forming a second tab extension portion along the width direction, spaced apart from the first tab extension portion, in a thickness direction of the electrode group intersecting both the length direction and the width direction, wherein the second tab extension portion is integrally formed with the first tab extension portion on the integral electrode group; forming an additional extension portion on the second tab extension portion, the additional extension portion extending beyond the first tab extension portion toward one side in the width direction of the electrode group; forming a lead by bending the leg portion toward one side of the top plate portion in a thickness direction of the top plate portion with a bending line along a width direction of the top plate portion, and forming the leg portion straight from a bending position relative to the top plate portion to a distal end relative to the top plate portion; connecting the top plate portion of the lead to a terminal; by arranging the terminal to which the top plate portion is connected at a position offset from the electrode group in the width direction of the electrode group, the additional extension portion of the second tab extension portion is extended beyond the first tab extension portion toward the side where the terminal is located, and by inserting the leg of the lead between the first tab extension portion and the second tab extension portion from the side where the terminal is located in the width direction of the electrode group, the lead is arranged in a state where the leg runs along the width direction of the electrode group from the bending position relative to the top plate portion to the distal end relative to the top plate portion; a first leg edge surface facing one side in a thickness direction of the electrode group on an outer surface of the leg portion arranged along the width direction of the electrode group is joined to the first tab extension portion of the current collecting tab, and a second leg edge surface facing the opposite side to the first leg edge surface is joined to the second tab extension portion of the current collecting tab by the additional extension portion, thereby electrically connecting the electrode group and the terminal; A method for manufacturing a battery comprising the steps of:

Images