CN117256075A

CN117256075A - Battery cell

Info

Publication number: CN117256075A
Application number: CN202180097559.9A
Authority: CN
Inventors: 森田修介; 荒木义朗; 矢野琢真
Original assignee: Toshiba Corp
Current assignee: Toshiba Corp
Priority date: 2021-09-03
Filing date: 2021-09-03
Publication date: 2023-12-19
Also published as: KR20230160335A; JPWO2023032151A1; WO2023032151A1

Abstract

The battery according to the embodiment includes: the electrode assembly comprises an outer part, an electrode terminal, an electrode group and a current collecting connecting plate. The electrode terminal is provided on the exterior member. The electrode group is accommodated in the internal cavity of the exterior member and has a protruding collector tab. The collector connection plate electrically connects the electrode terminal and the collector tab. The current collecting connection plate includes a substrate portion and a protruding portion. The substrate portion has a joint surface to be joined to the collector plate, and the joint surface faces one side in the first direction. The protruding portion is formed near the protruding end of the collector tab in a second direction intersecting the first direction, and protrudes from the substrate portion toward the side toward which the bonding surface faces in the first direction.

Description

Battery cell

Technical Field

Embodiments of the present invention relate to a battery.

Background

As a battery such as a lithium ion secondary battery, there is a structure in which an electrode group including a positive electrode and a negative electrode is housed in an internal cavity of an exterior member. In this battery, the electrode terminals are provided on the exterior member. The electrode group further includes a current collector and an active material-containing layer supported on the current collector. The current collector includes a current collector sheet as a portion on which the active material-containing layer is not supported. The collector tab is electrically connected to the electrode terminal via a collector connection plate such as a lead. Further, a plurality of belt-shaped portions are laminated on the current collector sheet.

In manufacturing such a battery, the plurality of laminated strip-shaped portions of the current collecting sheet are bonded to the current collecting connection plate or the like, for example, by ultrasonic bonding. When the band-shaped portion and the current collecting connection plate are joined in this manner, the band-shaped portion is deformed during the joining, and therefore the band-shaped portion and the current collecting tab may deviate from a predetermined position. In such joining, the current collecting tab is required to be joined to an appropriate position of the current collecting connection plate.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2015-103521

Patent document 2: japanese patent laid-open No. 2015-092457

Patent document 3: japanese patent laid-open publication No. 2011-192547

Patent document 4: japanese patent laid-open publication No. 2011-165437

Patent document 5: japanese patent application laid-open No. 2011-119264

Disclosure of Invention

First, the technical problem to be solved

The present invention provides a battery capable of joining a current collecting tab to a current collecting connection plate at a proper position.

(II) technical scheme

Drawings

Fig. 1A is a perspective view schematically showing an example of a battery according to an embodiment.

Fig. 1B is a perspective view schematically showing an example of a current collecting connection plate joined to a current collecting sheet of a battery according to an embodiment.

Fig. 2 is a cross-sectional view schematically showing an example of a structure of a portion where the collector tab and the collector connecting plate of fig. 1B are joined in a cross-section perpendicular to the height direction of the battery.

Fig. 3 is a cross-sectional view schematically showing a modification of the structure of the portion where the current collecting tab and the current collecting connecting plate of fig. 1B are joined, in a cross-section perpendicular to the height direction of the battery.

Fig. 4 is a cross-sectional view schematically showing a structure of a portion of the battery perpendicular to the height direction, at which the current collecting tab and the current collecting connecting plate of fig. 1B are joined, different from the modified example of fig. 3.

Fig. 5 is a cross-sectional view schematically showing a modified example of the battery according to the embodiment in a cross-section perpendicular to the depth direction of the battery.

Fig. 6 is a cross-sectional view schematically showing a modification of the battery according to the embodiment in a cross-section perpendicular to the lateral direction of the battery.

Detailed Description

The embodiments are described below with reference to the drawings.

(embodiment)

Fig. 1A shows a battery 1 according to an embodiment. As shown in fig. 1A, the battery 1 includes an electrode group 2 and an exterior member 3. The exterior member 3 includes an exterior container 5 and a lid member 6. The outer container 5 and the lid member 6 are each made of a metal such as aluminum, aluminum alloy, iron, copper, or stainless steel. Here, the battery 1 (the exterior container 5) is defined as follows: the direction of depth (the direction indicated by the arrow X1 and the arrow X2), the lateral direction (the direction indicated by the arrow Y1 and the arrow Y2) intersecting the direction of depth (orthogonal or substantially orthogonal), and the height direction (the direction indicated by the arrow Z1 and the arrow Z2) intersecting both the direction of depth and the lateral direction (orthogonal or substantially orthogonal). In both the battery 1 and the outer case 5, the dimension in the depth direction is smaller than the dimension in the lateral direction and the dimension in the height direction. Fig. 1A is a perspective view showing the components in an exploded manner.

The outer container 5 includes a bottom wall 7 and a peripheral wall 8. The internal cavity 10 for housing the electrode assembly 2 is defined by the bottom wall 7 and the peripheral wall 8. In the outer container 5, the inner cavity 10 is opened toward a side opposite to the side where the bottom wall 7 is located in the height direction. The cover member 6 is attached to the peripheral wall 8 at an end portion on the opposite side to the bottom wall 7. Thus, the lid member 6 closes the opening of the internal cavity 10 of the outer container 5. The lid member 6 and the bottom wall 7 face each other in the height direction across the internal cavity 10.

The electrode group 2 includes: a pair of electrodes 13, a pair of current collectors 14, and a pair of current collecting tabs 15. One of the pair of electrodes 13 is a positive electrode 13A, and the other of the pair of electrodes 13, which is different from the positive electrode 13A, is a negative electrode 13B. One of the pair of current collectors 14 is a positive electrode current collector 14A, and the other of the pair of current collectors 14, which is different from the positive electrode current collector 14A, is a negative electrode current collector 14B. One of the pair of collector tabs 15 is a positive electrode collector tab 15A, and the other of the pair of collector tabs 15, which is different from the positive electrode collector tab 15A, is a negative electrode collector tab 15B. A plurality of belt-shaped portions are bundled on each of the pair of current collecting tabs 15. In the electrode group 2, a separator (not shown) is interposed between the positive electrode 13A and the negative electrode 13B. The separator is made of an electrically insulating material, and electrically insulates the positive electrode 13A from the negative electrode 13B.

The positive electrode current collector 14A is formed of a positive electrode current collector foil or the like. A positive electrode active material-containing layer (not shown) is formed on the surface of the positive electrode current collector 14A. The positive electrode current collector 14A is, for example, aluminum foil or aluminum alloy foil. The thickness of the positive electrode current collector 14A is about 10 μm to 20 μm. The positive electrode active material-containing layer contains a positive electrode active material. The positive electrode active material-containing layer may optionally contain a binder and a conductive agent. The positive electrode active material is, for example, an oxide, sulfide, or polymer capable of absorbing and emitting lithium ions. The positive electrode collector sheet 15A is a portion of the positive electrode collector 14A on which the positive electrode active material-containing layer (not supported) is not supported. Positive electrode collector 15A protrudes from negative electrode 13B and the separator.

The negative electrode current collector 14B is formed of a negative electrode current collector foil or the like. A negative electrode active material-containing layer (not shown) is formed on the surface of the negative electrode current collector 14B. The negative electrode current collector 14B is, for example, aluminum foil, aluminum alloy foil, copper foil, or the like. The thickness of the negative electrode current collector 14B is about 10 μm to 20 μm. The negative electrode active material-containing layer is provided with a negative electrode active material. The anode active material-containing layer may optionally contain a binder and a conductive agent. The negative electrode active material is, for example, a metal oxide, a metal sulfide, a metal nitride, a carbon material, or the like capable of absorbing and desorbing lithium ions. The negative electrode collector sheet 15B is a portion of the negative electrode collector 14B on which the negative electrode active material-containing layer (not supported) is not supported. The negative electrode collector tab 15B protrudes to the opposite side of the positive electrode 13A from the positive electrode collector tab 15A.

In the electrode group 2 of the example, the positive electrode 13A, the negative electrode 13B, and the separator are wound around the winding axis W. The positive electrode 13A is offset to one side of the separator in the axial direction of the winding shaft W. Negative electrode 13B is offset from the separator toward the opposite side of positive electrode 13A in the axial direction. Therefore, the pair of collector tabs 15 (positive electrode collector tab 15A and negative electrode collector tab 15B) protrude outward in the axial direction with respect to the separator. In this case, the positive electrode collector tab 15A protrudes to one side in the axial direction with respect to the separator. The negative electrode collector tab 15B protrudes to the opposite side of the separator from the direction in which the positive electrode collector tab 15A protrudes.

In the electrode group 2 of the other example, a plurality of positive electrodes 13A and a plurality of negative electrodes 13B are alternately stacked. That is, the electrode group 2 is a stacked structure. The plurality of positive electrodes 13A are offset to one side with respect to the separator. The plurality of negative electrodes 13B are offset to the opposite side of the positive electrode 13A with respect to the separator. Therefore, the pair of collector tabs 15 protrude outward from the separator. Specifically, the positive electrode collector tab 15A protrudes in the lateral direction of the battery 1 with respect to the separator, and the negative electrode collector tab 15B protrudes in the lateral direction of the battery 1 with respect to the separator toward the opposite side of the positive electrode collector tab 15A.

In the following description, the electrode group 2 is described as the above-described wound electrode group, but the electrode group 2 is not limited thereto. As shown in fig. 1A, one of the pair of collector tabs 15 protrudes to one side in the lateral direction (axial direction along the winding axis W) of the battery 1. The other of the pair of collector tabs 15 protrudes in the lateral direction of the battery 1 to the opposite side of the direction in which one of the pair of collector tabs 15 protrudes. That is, the positive electrode collector tab 15A protrudes to one side in the lateral direction of the battery 1, and the negative electrode collector tab 15B protrudes to the other side in the lateral direction of the battery 1. Because of the above-described structure, the pair of collector tabs 15 do not contact each other.

A pair of backup leads 16 are attached to the pair of collector tabs 15 from the lateral outside of the battery 1. One of the pair of backup leads 16 is a positive-side backup lead 16A, and the other of the pair of backup leads 16, which is different from the positive-side backup lead 16A, is a negative-side backup lead 16B. The positive electrode side backup lead 16A is attached to the positive electrode collector tab 15A from the lateral outside. The negative electrode backup lead 16B is attached to the negative electrode collector tab 15B from the lateral outside. The positive electrode backup lead 16A is bundled by sandwiching a plurality of belt-shaped portions of the positive electrode collector tab 15A. The negative electrode backup lead 16B is bundled by sandwiching the band-shaped portion of the negative electrode collector tab 15B.

In the internal cavity 10, 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 13A and the negative electrode 13B instead of the separator. At this time, the positive electrode 13A is electrically insulated from the negative electrode 13B by the solid electrolyte.

In the battery 1, a pair of electrode terminals 17 are mounted on the outer surface of the cover member 6. The pair of electrode terminals 17 are exposed to the outside of the battery 1 and are disposed on the outer surface of the cover member 6. Therefore, the pair of electrode terminals 17 are provided to the exterior member 3. The pair of electrode terminals 17 are formed of a conductive material such as metal. One of the pair of electrode terminals 17 is a positive electrode terminal 17A of the battery 1. One of the pair of electrode terminals 17, which is different from the positive electrode terminal 17A, is a negative electrode terminal 17B of the battery 1. An insulating member 18 is provided between each of the pair of electrode terminals 17 and the cover member 6 on the outer surface of the cover member 6. The pair of electrode terminals 17 are electrically insulated from the outer case 5 and the lid member 6 by insulating members 18.

A pair of collector connection plates 30 are disposed in the inner cavity 10 of the outer case 5. One of the pair of collector connection plates 30 is a positive-side collector connection plate 30A. One of the pair of collector connection plates 30, which is different from the positive-side collector connection plate 30A, is a negative-side collector connection plate 30B. The positive-side current collecting connection plate 30A forms at least a part of an electrical path between the positive-electrode current collecting tab 15A and the positive-electrode terminal 17A. Therefore, the positive electrode collector tab 15A is electrically connected to the positive electrode terminal 17A through at least the positive electrode side collector connection plate 30A. The negative-side current collecting connection plate 30B forms at least a part of an electrical path between the negative current collecting tab 15B and the negative terminal 17B. Therefore, the negative electrode collector tab 15B is electrically connected to the negative electrode terminal 17B through at least the negative electrode side collector connection plate 30B. Each of the current collecting connection plates 30 is formed of a conductive material such as metal. The material forming the collector connection plate 30 is, for example, aluminum, stainless steel, copper, iron, or the like. The pair of collector connection plates 30 is, for example, a pair of leads.

A plurality of strip-shaped portions are laminated on each of the pair of current collecting tabs 15. When manufacturing the battery 1, before each of the current collecting tabs 15 is electrically connected to a corresponding one of the electrode terminals 17, a plurality of band-shaped portions are bundled by the backup lead 16 on each of the pair of current collecting tabs 15. Therefore, the plurality of belt-shaped portions bundled by the backup lead 16 on each of the current collecting tabs 15 are electrically connected to the corresponding one of the pair of electrode terminals 17 via the corresponding one of the pair of current collecting connection plates 30. Specifically, the plurality of belt-shaped portions of the positive electrode collector tab 15A bundled by the positive electrode side backup lead 16A are electrically connected to the positive electrode terminal 17A via the positive electrode side collector connection plate 30A. The plurality of belt-shaped portions of the negative electrode collector tab 15B bundled by the negative electrode side backup lead 16B are electrically connected to the negative electrode terminal 17B via the negative electrode side collector connection plate 30B.

In one example of fig. 1A, a gas release valve 19 and a liquid filling port (not shown) are formed in the cover member 6. A sealing plate 20 for closing the liquid inlet is welded to the outer surface of the lid member 6. The battery 1 may not be provided with the gas release valve 19, the liquid filling port, and the like. In the internal cavity 10 of the outer case 5, the pair of collector tabs 15 and the pair of collector tabs 30 are electrically insulated from the outer case 5 by 1 or more insulating members (not shown).

Next, the joint between the pair of collector tabs 15 and the pair of collector connecting plates 30 will be described. Fig. 1B is a perspective view schematically showing an example of a current collecting connection plate joined to a current collecting sheet of a battery according to an embodiment. Fig. 2 is a cross-sectional view schematically showing the structure in the vicinity of the junction of collector tab 15 and collector connecting plate 30 in a cross-section perpendicular to the height direction of the battery. In fig. 1B and 2, the height direction, the lateral direction, and the depth direction of the battery 1 are defined as in fig. 1A. As shown in fig. 1B and 2, the current collecting connection plate 30 has a first direction (indicated by an arrow X3 and an arrow X4) aligned with or substantially aligned with the depth direction of the battery 1. The second direction (indicated by arrows Y3 and Y4) intersects (is orthogonal or substantially orthogonal to) the first direction. The third direction (indicated by arrows Z3 and Z4) intersects (is orthogonal or substantially orthogonal to) both the first direction and the second direction.

In the present embodiment, the second direction coincides or substantially coincides with the lateral direction of the battery 1. The second direction is identical or substantially identical to the protruding direction of the collector tab 15 protruding from the electrode group 2 and the direction opposite to the protruding direction. The third direction coincides or substantially coincides with the height direction of the battery 1. The joint is formed, for example, at a connection portion between the current collecting tab 15 and the current collecting connection plate 30. Thereby, the collector tab 15 is joined to the collector connection plate 30, and the collector tab 15 and the collector connection plate 30 are electrically connected. The joint is formed, for example, by a horn (ultrasonic horn) used for ultrasonic joining.

Each of the pair of current collecting connection plates 30 includes: a base plate 31, a protruding portion 32, and a top plate 33. The positive electrode-side current collecting connection plate 30A includes: positive electrode side substrate 31A, positive electrode side protruding portion 32A, and positive electrode side top plate 33A. The negative electrode side current collecting connection plate 30B includes: a negative electrode side base plate 31B, a negative electrode side protruding portion 32B, and a negative electrode side top plate 33B. A positive electrode-side joint is formed between the positive electrode collector tab 15A and the positive electrode-side collector connection plate 30A, and a negative electrode-side joint is formed between the negative electrode collector tab 15B and the negative electrode-side collector connection plate 30B.

Here, the positive electrode-side current collecting connection plate 30A is configured in the same manner as the negative electrode-side current collecting connection plate 30B. The positive electrode side joint is configured in the same manner as the negative electrode side joint. Therefore, the description of the structure similar to that of the positive electrode side joint portion is also true for the negative electrode side joint portion. Therefore, the positive electrode side current collecting connection plate 30A, the positive electrode current collecting plate 15A, and the positive electrode side joint are described below as the current collecting connection plate 30, the current collecting plate 15A, and the joint, and the description of the negative electrode side current collecting connection plate 30B, the negative electrode current collecting plate 15B, and the negative electrode side joint is omitted. The joint portion of the present embodiment may not be formed in both of the pair of current collecting tabs 15. That is, the joint portion may be formed only on one of the pair of collector tabs 15, or may be formed on both of the pair of collector tabs 15. The current collecting connection plate 30 of the present embodiment may not be used for both of the pair of current collecting connection plates 30. That is, the collector connection plate 30 may be used for only one of the pair of collector connection plates 30, or may be used for both of the pair of collector connection plates 30.

As shown in fig. 1B, the current collecting connection plate 30 includes: a base plate 31, a protruding portion 32, and a top plate 33. The base plate portion 31 and the protruding portion 32 of the collector connecting plate 30 are provided so as to extend in the height direction of the battery 1, that is, in the third direction of the collector connecting plate 30. As shown in fig. 1B and 2, the substrate portion 31 includes: a joint surface S1, a bottom surface S2, and a pair of side surfaces S3, S4. The protruding portion 32 includes: a protruding end S5, a pair of side surfaces S6, S7. Backup leads 16 (collector tabs 15) are bonded to the collector connection plate 30 from one side in the first direction on the substrate portion 31. As described above, the backup lead 16 is attached to the current collecting tab 15 from the lateral outside of the battery 1, thereby bundling the band-shaped portion of the current collecting tab 15. With this configuration, if the backup lead 16 is bonded to the current collecting connection plate 30, the band-shaped portion of the current collecting tab 15 is connected to the current collecting connection plate 30 via the backup lead 16. That is, the current collecting tab 15, the backup lead 16, and the current collecting connection plate 30 are electrically connected.

The joint surface S1 forms one end surface of the substrate portion 31 in the first direction of the current collecting connection plate 30. The bottom surface S2 forms an end surface of the substrate portion 31 on the opposite side of the joint surface S1 in the first direction of the current collecting connection plate 30. In the present embodiment, the bottom surface S2 forms an end surface of the substrate portion 31 on the opposite side of the protruding portion 32 in the first direction of the current collecting connection plate 30. In the substrate portion 31, the bottom surface S2 and the joint surface S1 face each other in the first direction of the current collecting connection plate 30. The pair of side surfaces S3 and S4 face each other in the second direction of the current collecting connection plate 30. One side surface S3 of the pair of side surfaces is provided on the side of the electrode group 2 in the second direction of the current collecting connection plate 30. The other side surface S4 of the pair of side surfaces is provided on the side farther from the electrode group 2 than the side surface S3 in the second direction of the current collecting connection plate 30. Bottom surface S2 extends from side surface S3 to side surface S4 in the second direction of collector connecting plate 30. The pair of side surfaces S3 and S4 extend from the joint surface S1 to the bottom surface S2 in the first direction of the current collecting connection plate 30.

The protruding portion 32 protrudes from the joint surface S1 of the substrate portion 31 in the first direction of the current collecting connection plate 30. The protruding end S5 forms the front end of the protruding portion 32 in the protruding direction. The protruding end S5 is provided on the opposite side of the bottom surface S2 of the substrate portion 31 in the first direction of the current collecting connection plate 30. The pair of side surfaces S6 and S7 face each other in the second direction of the current collecting connection plate 30. One side surface S6 of the pair of side surfaces is provided on the side of the electrode group 2 in the second direction of the current collecting connection plate 30. The other side surface S7 of the pair of side surfaces is provided on the side farther than the side surface S6 with respect to the collector tab 15 in the second direction of the collector connecting plate 30. And, the protruding end S5 extends from the side surface S6 to the side surface S7 in the second direction of the current collecting connection plate 30. Further, the protruding portion 32 does not have to be formed in the full size in the first direction of the collector connecting plate 30. That is, the protruding portion 32 may be formed at least in part along the first direction of the current collecting connection plate 30.

The protruding portion 32 is provided at a position away from the electrode group 2 toward one of the second directions of the current collecting connection plates 30. In the present embodiment, the protruding portion 32 is located on the side of the exterior member 3 with respect to the joint surface S1 in the second direction of the collector connecting plate 30, and forms an end portion of the collector connecting plate 30. That is, the protruding portion 32 is provided at a position where the side surface S7 of the protruding portion 32 is flush with the side surface S4 of the substrate portion 31. Accordingly, the side surface S7 of the protruding portion 32 and the side surface S4 of the substrate portion 31 form the side surface S8 of the current collecting connection plate 30. The side surface S8 of the collector connection plate 30 is provided on the opposite side of the side surface S3 of the substrate portion 31 in the second direction of the collector connection plate 30. At this time, the joint surface S1 of the substrate 31 is provided between the side surface S3 of the substrate 31 and the side surface S6 of the protruding portion 32 so as to extend in the second direction of the current collecting connection plate 30.

Since the joint surface S1 of the plate portion 31 is formed in this way, the side surface S6 of the protruding portion 32 is connected to the joint surface S1 at an end opposite to the end of the joint surface S1 formed by the side surface S3 in the second direction of the current collecting connection plate 30. The side surface S6 of the protruding portion 32 is raised from one end of the joint surface S1 toward the opposite side of the bottom surface S2 in the first direction of the current collecting connection plate 30. The side surface S6 of the protruding portion 32 extends from the raised portion of the side surface S6 to the protruding end S5 in the first direction of the current collecting connection plate 30. The protruding end S5 of the protruding portion 32 extends from the side surface S6 of the protruding portion 32 to the side surface S8 of the current collecting connection plate 30 in the second direction of the current collecting connection plate 30. Since the substrate portion 31 and the protruding portion 32 are formed on the current collecting connection plate 30 as described above, the current collecting connection plate 30 is formed in an L shape or a substantially L shape in the cross section shown in fig. 2.

The top plate portion 33 is located on the side of the electrode terminal 17 with respect to the joint portion (joint surface S1) of the collector tab 15 in the third direction of the collector connection plate 30. The top plate portion 33 is connected to one end of the substrate portion 31 on the side where the electrode terminals 17 are located in the third direction of the collector connection plate 30. Therefore, the top plate 33 is provided closer to the electrode terminal 17 than the collector tab 15 in the third direction of the collector connection plate 30. The protruding portion 32 is connected to the top plate portion 33 from the opposite side of the current collecting connection plate 30 to the side where the electrode terminal 17 is located in the third direction. That is, the protruding end S5 of the protruding portion 32 is connected to the top plate 33.

The backup lead 16 includes a pair of flat plate portions 161 and a folded portion 162. The pair of flat plate portions 161 are connected to the folded portion 162 at one end of the opposite side of the edges E (E1, E2). One of the pair of flat plate portions 161 is a flat plate portion 161A, and the other of the pair of flat plate portions 161 is a flat plate portion 161B. The flat plate portion 161A faces the flat plate portion 161B in one of the plate thickness directions of the flat plate portion 161A. The flat plate portion 161A extends from the edge E1 to a connection portion with the folded portion 162. The flat plate portion 161B extends from the edge E2 to a connection portion with the folded portion 162. The folded portion 162 folds the flat plate portion 161A back with respect to the flat plate portion 161B. As described above, in the present embodiment, the backup lead 16 is attached to the collector tab 15 from the lateral outside of the battery 1. Further, the backup lead 16 (collector tab 15) is bonded to the bonding surface S1, so that the collector tab 15, the backup lead 16, and the collector connection plate 30 are electrically connected.

Since the backup lead 16 is attached to the current collecting tab 15 in this way, the pair of flat plate portions 161 face each other in the first direction of the current collecting connection plate 30. One of the pair of flat plate portions 161 (flat plate portion 161B) is joined to the joint surface S1 from one side of the current collecting connection plate 30 in the first direction. The folded portion 162 is disposed on the side of the protruding portion 32 with respect to the pair of flat plate portions 161 in the second direction of the current collecting connection plate 30. The folded-back portion 162 is in contact with the side surface S6 of the protruding portion 32 from the side where the electrode group 2 is located in the second direction of the collector connecting plate 30. Therefore, the backup lead 16 is not provided at a position beyond the protruding portion 32 in the protruding direction of the collector tab 15. That is, the side surface S6 of the protruding portion 32 restricts in the second direction of the current collecting connection plate 30: the protruding ends of the folded-back portions 162 and the current collecting tabs 15 move toward the side where the exterior member 3 is located. The folded portion 162 may be at least partially in contact with the side surface S6 of the protruding portion 32 from the side where the electrode group 2 is located in the second direction of the current collecting connection plate 30.

The side surface S6 of the protruding portion 32 is preferably formed in a shape following the shape of the folded back portion 162. In the example shown in fig. 2, in the folded-back portion 162, the surface of the side on which the protruding portion 32 is located is opposed to the side surface S6 of the protruding portion 32 in the second direction of the current collecting connection plate 30. In this case, the side surface S6 of the protruding portion 32 is formed in a planar shape or a substantially planar shape. In addition, the side surface S6 of the protruding portion 32 is located on the side of the exterior member 3 (the exterior container 5) than the protruding end of the collector tab 15 in the second direction of the collector connecting plate 30. The side surface S6 of the protruding portion 32 is an approaching surface that approaches the protruding end of the collector tab 15 from the side where the exterior member 3 is located in the second direction of the collector connecting plate 30 through the folded-back portion 162 of the backup lead 16.

Next, the dimensions of the current collecting connection plate 30 will be described. The current collecting connection plate 30 defines a dimension T1, a dimension T2, a dimension T3, a dimension W1, a dimension W2, and a dimension W3. The dimension T1, the dimension T2, and the dimension T3 are all dimensions along the first direction of the current collecting connecting plate 30. The dimension T1 is the plate thickness of the substrate portion 31 along the first direction of the current collecting connection plate 30. That is, the dimension T1 is a dimension between the joint surface S1 and the bottom surface S2 along the first direction of the current collecting connecting plate 30. The dimension T2 is the protruding amount of the protruding portion 32 from the substrate portion 31 in the first direction of the current collecting connection plate 30. That is, the dimension T2 is the dimension between the joint surface S1 and the protruding end S5 along the first direction of the current collecting connecting plate 30. The dimension T3 is a dimension between the bottom surface S2 and the protruding end S5 along the first direction of the collector connecting plate 30.

The dimension W1, the dimension W2, and the dimension W3 are all dimensions along the second direction of the current collecting connecting plate 30. The dimension W1 is the dimension of the joint surface S1 along the second direction of the current collecting connecting plate 30. That is, the dimension W1 is a dimension between the side surface S3 of the substrate portion 31 and the side surface S6 (the raised portion of the side surface S6 from the joint surface S1) of the protruding portion 32 along the second direction of the current collecting connection plate 30. The dimension W2 is the dimension of the protruding portion 32 along the second direction of the current collecting connecting plate 30. That is, the dimension W2 is a dimension between the pair of side surfaces S6, S7 of the protruding portion 32 along the second direction of the current collecting connecting plate 30. The dimension W3 is a dimension between the pair of side surfaces S3, S4 of the substrate portion 31 along the second direction of the current collecting connection plate 30. However, as shown in an example of fig. 2, when the side surface S7 of the protruding portion 32 is flush with the side surface S4 of the substrate portion 31, the dimension W3 is identical or substantially identical to the dimension between the side surface S3 of the substrate portion 31 and the side surface S8 of the collector connecting plate 30.

In collector connection plate 30, dimension W1 is larger than dimension W2. That is, W1 > W2. The dimension W1 is preferably equal to or larger than the dimension of the backup lead 16 in the second direction of the current collecting connection plate 30. The dimension of the backup lead 16 in the second direction of the collector connecting plate 30 is the dimension in the second direction of the collector connecting plate 30 between the edge E of the pair of flat plate portions 161 and the end of the side of the protruding portion 32 on the folded-back portion 162. Since the dimension W1 and the dimension of the backup lead 16 in the second direction of the collector connecting plate 30 satisfy such a relationship, in the case where the backup lead 16 is bonded to the bonding surface S1 of the collector connecting plate 30, the backup lead 16 does not exceed the side surface S3 of the substrate portion 31 on the side where the electrode group 2 is located in the second direction of the collector connecting plate 30.

When the dimension W1 is the same as or substantially the same as the dimension of the backup lead 16 in the second direction of the collector connecting plate 30, the backup lead 16 is bonded to the bonding surface S1 of the collector connecting plate 30 (the substrate portion 31) by the arrangement in which the folded-back portion 162 is in contact with the side surface S6 of the protruding portion 32. In this case, the edges E1 of the pair of flat plate portions 161 of the backup lead 16 are at the same position or substantially the same position as the side face S3 of the substrate portion 31 in the second direction of the collector connecting plate 30. When the dimension W1 is larger than the dimension of the backup lead 16 in the second direction of the collector connecting plate 30, the backup lead 16 is bonded to the bonding surface S1 of the collector connecting plate 30 (the substrate portion 31) also at the position where the folded-back portion 162 contacts the side surface S6 of the protruding portion 32. In this case, the edges E1 of the pair of flat plate portions 161 of the backup lead 16 are disposed closer to the side of the protruding portion 32 than the side surface S3 of the substrate portion 31 in the second direction of the collector connecting plate 30.

As described above, in the present embodiment, the current collecting connection plate 30 includes: a joint surface S1, a base plate 31, and a protruding portion 32. The substrate 31 has a bonding surface S1. The bonding surface S1 faces the first direction and is bonded to the collector tab 15. The protruding portion 32 is formed adjacent to the protruding end of the collector tab 15 in a second direction intersecting the first direction, and protrudes from the substrate portion 31 toward the side toward which the bonding surface S1 faces in the first direction. Since the protruding ends of the collector tabs 15 and the protruding portions 32 are arranged in this way, it is possible to effectively prevent: when the collector tab 15 is engaged with the collector connection plate 30, the protruding end of the collector tab 15 exceeds the protruding portion 32 in the second direction. Therefore, in the battery 1 of the present embodiment, the current collecting tab 15 can be bonded to the current collecting connection plate 30 at an appropriate position.

In the present embodiment, the protruding portion 32 preferably has an approaching surface. The approaching surface is provided on the side of the exterior member 3 in the second direction of the collector connecting plate 30 as compared with the protruding end of the collector tab 15, and approaches the collector tab 15 from the side of the exterior member 3 in the second direction of the collector connecting plate 30. In addition, the approach surface is directed to the side where the protruding end of the collector tab 15 is located. The proximity surface is preferably formed in a shape that follows the shape of a portion adjacent to the proximity surface from the side toward which the proximity surface faces in the second direction of the current collecting connection plate 30. In the present embodiment, the side surface S6 of the protruding portion 32 functions as an approaching surface. By forming the proximity surface in this way, when the current collecting tab 15 is joined to the joint surface S1, the current collecting tab 15 can be arranged at a position adjacent to the protruding portion 32 in the second direction. Therefore, it is possible to effectively prevent: when the current collecting tab 15 and the current collecting connection plate 30 are connected by, for example, ultrasonic bonding, the protruding end of the current collecting tab 15 is deformed beyond the approaching surface of the protruding portion 32 in the second direction. In addition, when the current collecting tab 15 is joined to the joint surface S1, the position of the current collecting tab 15 can be easily matched to a predetermined portion of the current collecting connection plate 30. Therefore, in the battery 1 of the present embodiment, the current collecting tab 15 can be bonded to the current collecting connection plate 30 at an appropriate position.

In the current collecting connection plate 30 of the present embodiment, it is preferable that the dimension T3 in the first direction between the protruding end S5 of the protruding portion 32 and the bottom surface S2 of the substrate portion 31 is larger than the dimension T1 in the first direction between the joint surface S1 and the bottom surface S2 of the substrate portion 31. By forming the protruding portion 32 in this manner, for example, the cross-sectional area of the cross-section (cross-section orthogonal or substantially orthogonal to the third direction of the current collecting connection plate 30) shown in the example of fig. 2 is increased in the current collecting connection plate 30. Therefore, heat generated by the current flowing through the collector connection plate 30 is reduced. Thereby suppressing the temperature rise of the collector connection plate 30 due to the generation of this heat. In addition, by forming the protruding portion 32 on the current collecting connection plate 30, the rigidity of the current collecting connection plate 30 is improved. Therefore, the deformation of the current collecting connection plate 30 can be suppressed.

In the current collecting connection plate 30 of the present embodiment, it is preferable that the dimension W2 in the second direction of the protruding portion 32 is smaller than the dimension W1 in the second direction between the portion where the side surface S6 of the protruding portion 32, which is the approach surface, stands up from the joint surface S1 and the one end of the substrate portion 31 on the opposite side to the side where the protruding portion 32 is formed in the second direction. By forming the protruding portion 32 in this manner, for example, the region where the current collecting tab 15 is joined can be ensured while maintaining the dimension W3 of the current collecting connection plate 30 at or below a predetermined size.

The protruding portion 32 of the present embodiment is preferably formed at the end of the collector connecting plate 30 on the exterior member 3 side in the second direction. By forming the protruding portion 32 in this manner, for example, the joint surface S1, which is a portion joined to the current collector 15, can be sufficiently secured. Therefore, when the position of collector tab 15 is matched with a predetermined portion of collector connection plate 30, the degree of freedom in arrangement of collector tab 15 is improved. Therefore, in the battery 1 of the present embodiment, the current collecting tab 15 can be bonded to the current collecting connection plate 30 at an appropriate position.

(modification)

Fig. 3 is a cross-sectional view schematically showing a modification of the structure in the vicinity of the junction of collector tab 15 and collector connecting plate 30 in a cross-section perpendicular to the height direction of battery 1. In fig. 3, the height direction, the lateral direction, the depth direction, and the first, second, and third directions of the current collecting connection plates 30 of the battery 1 are defined as in fig. 1A, 1B, and 2.

In the modification shown in fig. 3, the backup lead 16 is not attached to the collector tab 15 of the battery 1. That is, the band-shaped portion of the bundle of the collector tab 15 is directly joined to the joint surface S1 of the collector connecting plate 30. When backup lead 16 is not attached to current collecting tab 15 in this way, current collecting tab 15 is pressed from the first direction side of current collecting connection plate 30, and current collecting tab 15 is bonded to current collecting connection plate 30. In the present modification, the protruding end of the collector tab 15 is in contact with the side surface S6 of the protruding portion 32 as the approaching surface from the side surface S3 of the collector connecting plate 30. Therefore, as in the foregoing embodiment, the current collecting tab 15 is not provided at a position beyond the protruding portion 32 in the second direction of the current collecting connection plate 30.

In the case where the backup lead 16 is not provided in this way, the dimension T2 of the protruding portion 32 is preferably larger than the dimension between the bonding surface S1 of the current collecting connection plate 30 and the surface of the current collecting tab 15 on the opposite side of the surface bonded to the bonding surface S1. That is, the protruding end S5 of the protruding portion 32 is disposed at a position farther from the joint surface S1 (the base plate portion 31) than the surface of the current collecting tab 15 opposite to the surface joined to the joint surface S1 in the first direction of the current collecting connection plate 30. Therefore, when the current collecting tab 15 is joined to the current collecting connection plate 30, if the current collecting tab 15 is deformed in the second direction of the current collecting connection plate 30 toward the side where the protruding portion 32 is located, the protruding end of the current collecting tab 15 contacts the side surface S6 of the protruding portion 32. Therefore, the current collecting tab 15 can be effectively restricted from being provided at a position beyond the protruding portion 32 in the second direction of the current collecting connection plate 30. Further, since the protruding end of the collector tab 15 is in contact with the side surface S6 of the protruding portion 32, the position of the collector tab 15 can be easily matched with a predetermined portion of the collector connection plate 30.

Fig. 4 is a cross-sectional view schematically showing a structure in the vicinity of a joint portion of the current collecting tab 15 and the current collecting connecting plate 30 in a cross-section perpendicular to the height direction of the battery, which is different from the modification example of fig. 3. In fig. 4, the height direction, the lateral direction, the depth direction, and the first, second, and third directions of the current collecting connection plates 30 of the battery 1 are defined as in fig. 1A to 3. In the modification shown in fig. 4, the side surface S6 of the protruding portion 32 is inclined with respect to the joint surface S1. The side surface S6 of the protruding portion 32 is formed in the following state: the closer to the protruding end S5 in the first direction of the current collecting connection plate 30, the more toward the side surface S7 of the protruding portion 32 in the second direction of the current collecting connection plate 30. By forming the side surface S6 of the protruding portion 32 in this manner, the side surface S6 can follow the shape of the protruding end of the band-shaped portion of the binding of the current collector 15. For example, as shown in fig. 4, when the band-shaped portion of the collector sheet 15 is bundled, the band-shaped portion of the collector sheet 15 may be formed in a tapered shape or a substantially tapered shape in which the thickness of the band-shaped portion is thinner as it goes toward the protruding end of the collector sheet 15, as viewed from one of the third directions of the collector connection plates 30. In this case, in the present modification, since the side surface S6 of the protruding portion 32 is inclined as described above, the position of the collector tab 15 can be easily matched with a predetermined portion of the collector connection plate 30.

When the protruding portion 32 is formed in this way, the dimensions T1, T2, T3, W1, W2, and W3 are defined as in the foregoing embodiment and the like. Therefore, the same relationship as in the foregoing embodiment and the like regarding the dimensions is also true in the present modification.

The shape of the protruding portion 32 is not limited to the shape of the foregoing embodiment and modification example, and can be appropriately set in accordance with the shape of the current collecting connection plate 30, the shape of the band-shaped portion of the current collecting tab 15 (the shape of the protruding end of the current collecting tab 15), and the like. In one example, the side surface S7 of the protruding portion 32 may be inclined with respect to the joint surface S1. That is, the side surface S7 of the protruding portion 32 may be formed in the following state: the closer to the protruding end S5 in the first direction of the collector connecting plate 30, the closer to the collector tab 15 in the second direction of the collector connecting plate 30. In another example, the protruding portion 32 may be formed in the following shape: as the protruding end S5 is oriented in the first direction of the current collecting connection plate 30, the dimension along the second direction of the current collecting connection plate 30 becomes smaller. That is, the protruding portion 32 may be formed as: the protruding surface of the protruding portion 32 is tapered as seen from one of the third directions of the collector connecting plate 30, the more the direction of the collector connecting plate 30 is toward the protruding portion 32.

Fig. 5 is a cross-sectional view schematically showing a modification of the battery 1 according to the embodiment in a cross-section of the battery 1 perpendicular to the depth direction. Fig. 6 is a cross-sectional view schematically showing a modification of the battery 1 according to the embodiment in a cross-section perpendicular to the lateral direction of the battery 1. The height direction, the lateral direction, and the depth direction of the battery 1 are also defined in the battery 1 shown in fig. 5 and 6. However, in the battery 1 of the present modification, the first direction (indicated by the arrow Z5 and the arrow Z6) coincides or substantially coincides with the height direction of the battery 1 in the current collecting connection plate 30. The second direction (indicated by arrows X5 and X6) coincides or substantially coincides with the depth direction of the battery 1. The third direction (indicated by arrow Y5 and arrow Y6) coincides or substantially coincides with the lateral direction of the battery 1.

In the battery 1 of the present modification, the pair of current collecting tabs 15 protrude toward the same side as each other. The pair of collector tabs 15 protrude from the electrode group 2 to the side on which the pair of electrode terminals 17 are located in the height direction of the battery 1. In this modification, too: the pair of collector tabs 15 do not contact each other. Specifically, the positive electrode collector tab 15A protrudes from the electrode group 2 toward the positive electrode terminal 17A. The negative electrode collector tab 15B protrudes from the electrode group 2 to the side where the negative electrode terminal 17B is located. In this case, as shown in fig. 5 and 6, similarly to any of the embodiments and the like, the protruding portion 32 of the current collecting connection plate 30 is formed close to the protruding end of the current collecting tab 15 in the second direction, and protrudes from the substrate portion 31 toward the side toward which the joint surface S1 faces in the first direction. Thus, the battery 1 according to the present modification achieves the same effects as those of the foregoing embodiment and the like.

According to at least 1 of these embodiments, a collector connecting plate for electrically connecting an electrode terminal and a collector sheet includes: a base plate and a protruding part. The substrate portion has a joint surface to be joined to the collector plate, and the joint surface faces one side in the first direction. The protruding portion is formed near the protruding end of the collector tab in a second direction intersecting the first direction, and protrudes from the substrate portion toward the side toward which the bonding surface faces in the first direction. In this way, in the battery according to the embodiment, the current collecting tab can be bonded to the current collecting connection plate at an appropriate position.

While the present invention has been described with reference to several embodiments, these embodiments are presented by way of example and do not limit the scope of the invention. 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 invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the scope equivalent thereto.

Claims

1. A battery is provided with:

an exterior member;

an electrode terminal provided on the exterior member;

an electrode group which is accommodated in the internal cavity of the exterior member and which has a protruding collector tab; and

a collector connection plate that electrically connects the electrode terminal and the collector sheet,

the current collecting connection plate is provided with:

a substrate portion having a joint surface to be joined to the collector sheet, the joint surface facing one side in a first direction; and

and a protruding portion that is formed near a protruding end of the collector tab in a second direction intersecting the first direction and protrudes from the substrate portion toward a side toward which the bonding surface faces in the first direction.

2. The battery of claim 1, wherein the battery is configured to provide the battery with a plurality of cells,

the protruding portion has an approaching surface that approaches the collector sheet in the second direction from a side where the exterior member is located, and faces a side where the protruding end of the collector sheet is located, as compared with the protruding end of the collector sheet.

3. The battery of claim 2, wherein the battery is configured to provide the battery with a plurality of cells,

the substrate portion has a bottom surface provided on a side opposite to a side on which the protruding portion is provided in the first direction,

in the current collecting connection plate, a dimension in the first direction between a tip end of the protruding portion and the bottom surface of the substrate portion is larger than a dimension in the first direction between the joint surface and the bottom surface.

4. A battery according to claim 2 or 3, wherein,

in the current collecting connection plate, a dimension of the protruding portion in the second direction is smaller than a dimension of the second direction between a portion of the approach surface rising from the joint surface and one end of the substrate portion on a side opposite to a side on which the protruding portion is formed in the second direction.

5. The battery according to any one of claim 1 to 4, wherein,

the protruding portion forms an end portion of the collector connecting plate on the exterior member side in the second direction.

6. The battery according to any one of claims 1 to 5, wherein,

the electrode terminal is provided on one side of the electrode group in a third direction intersecting both the first direction and the second direction.

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

the current collecting connection plate includes a top plate portion which is located on the side where the electrode terminal is located with respect to the joint surface in the third direction and which is connected to the electrode terminal,

the protruding portion is connected to the top plate portion from a side opposite to a side where the electrode terminal is located in the third direction.

8. The battery according to any one of claims 1 to 7, wherein,

the current collecting sheet includes: a positive electrode collector tab protruding in the electrode group, and a negative electrode collector tab protruding in the electrode group in a state of not being in contact with the positive electrode collector tab,

at least one of the current collecting connection plate in which the junction surface is joined to the positive current collecting tab and the current collecting connection plate in which the junction surface is joined to the negative current collecting tab is provided.