Composite current collector for secondary battery

Abstract

The utility model provides a composite current collector for a secondary battery, comprising a current collector body and a conductive connector, wherein the conductive connectors are overlapped on opposite sides of the current collector body, a weld mark is provided at the overlapped portion of the current collector body and the conductive connector, and a cutting groove is provided in the weld mark area; by providing the cutting groove in the weld mark area, the cutting groove is a weak area of ​​the welding electrical connection part, and when the pole ear is bent, the bending is performed in the weak area, which, on the one hand, reduces the space required for bending in the welding area, and on the other hand, reduces the risk of the pole ear tearing in the welding area.

Description

Technical Field

[0001] The utility model relates to the field of lithium ion batteries, in particular to a composite current collector for secondary batteries. Background Art

[0002] The current collector refers to a structure or part that collects current. The current collector is used to connect the tabs and collect the current generated by the active material of the battery to form a larger current output. Composite current collectors have the advantages of small thickness and high stability, and are therefore widely used.

[0003] The composite current collector is a metal layer coated on an insulating film, and on this basis, the metal layers on both sides of the insulating film are welded together with their respective pole ears, thereby connecting the metal layers on both sides. The existing one-piece roll welding connection method has a wide roll welding width, which is not conducive to the bending of the pole ears here.

[0004] Therefore, we propose a composite current collector for secondary batteries to solve the problem that the tab is difficult to bend at the welding point. Utility Model Content

[0005] The purpose of the utility model is to solve the shortcomings of the prior art. In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A composite current collector for a secondary battery comprises a current collector body and a conductive connector, wherein the conductive connectors are overlapped on opposite sides of the current collector body, a weld mark is provided at the overlapped portion of the current collector body and the conductive connector, and a cutting groove is provided in the weld mark region; by providing the cutting groove in the weld mark region, the cutting groove is a weak region of the welding electrical connection portion, and when the tab is bent, the bending is performed in the weak region, which reduces the space required for bending in the welding region on the one hand, and reduces the risk of the tab tearing in the welding region on the other hand.

[0007] Further preferably, the length direction of the current collector body is the X direction, the width direction of the current collector body is the Y direction, the weld mark is rectangular, the width A of the weld mark in the X direction is 0-100 mm, and the length B of the weld mark in the Y direction is 0-500 mm.

[0008] Further preferably, the cutting groove is rectangular, and at least one cutting groove is provided in the weld stamp area. The width of the cutting groove in the X direction is D, and the length in the Y direction is C. D is smaller than A, and C is smaller than B.

[0009] Further preferably, the cutting groove is centrally distributed in the weld mark area.

[0010] Further preferably, the cutting groove passes through the current collector body and the conductive connecting member.

[0011] Further preferably, the current collector body includes an insulating layer and a first metal layer and a second metal layer respectively coated on both sides of the insulating layer.

[0012] Further preferably, the conductive connector includes a first pole tab and a second pole tab, and the upper and lower surfaces of the current collector body are connected to the first pole tab and the second pole tab by welding.

[0013] Compared with the prior art, the beneficial effects of the utility model are:

[0014] The utility model connects the pole ear with the current collector body through welding marks. A cutting groove is arranged in the welding mark area. The cutting groove is a weak area of ​​the welding electrical connection part. When the pole ear is bent, the bending is performed in the weak area. On the one hand, the space required for bending in the welding area is reduced, and on the other hand, the risk of the pole ear tearing in the welding area is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is the front view of the utility model;

[0016] Figure 2 It is a schematic diagram of the explosion structure of the utility model.

[0017] In the figure: current collector body 1, conductive connector 2, weld mark 3, cutting groove 4, insulating layer 11, first metal layer 12, first pole ear 13, second metal layer 14, second pole ear 15. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0019] Reference Figure 1-Figure 2 A composite current collector for a secondary battery comprises a current collector body 1 and a conductive connector 2, wherein the conductive connector 2 is overlapped on opposite sides of the current collector body 1, a weld mark 3 is provided at the overlapped portion of the current collector body 1 and the conductive connector 2, and a cutting groove 4 is provided in the weld mark 3 region; by providing the cutting groove in the weld mark region, the cutting groove is a weak region of the welding electrical connection portion, and when the tab is bent, the tab is bent in the weak region, which reduces the space required for bending in the welding region on the one hand, and reduces the risk of tab tearing in the welding region on the other hand.

[0020] The length direction of the current collector body 1 is the X direction, the width direction of the current collector body 1 is the Y direction, the weld mark 3 is rectangular, the width A of the weld mark 3 in the X direction is 0-100 mm, and the length B of the weld mark 3 in the Y direction is 0-500 mm.

[0021] The cutting groove 4 is rectangular. In the weld area, at least one cutting groove 4 is provided. The width of the cutting groove 4 in the X direction is D, and the length in the Y direction is C. D is smaller than A, and C is smaller than B.

[0022] The cutting groove 4 is centrally distributed in the weld mark 3 area; the cutting groove 4 passes through the current collector body 1 and the conductive connecting member 2 .

[0023] In the embodiment: the width A of the weld mark 3 is 50 mm, and the length B is 120 mm; it is centrally distributed at the overlap portion of the current collector body 1 and the conductive connector 2, and in the regional weld, there is one cutting groove 4 in the X direction and one cutting groove 4 in the Y direction; in the X direction, the width D of the cutting groove 4 is 20 mm, centrally distributed, and the length C of the cutting groove 4 is 80 mm, centrally distributed. When the tab is bent, it is bent in the weak area of ​​the cutting groove 4, which reduces the space required for bending in the welding area on the one hand, and reduces the risk of tab tearing in the welding area on the other hand.

[0024] In the embodiment: the width A of the weld mark 3 is 50 mm, and the length B is 120 mm; it is centrally distributed at the overlap portion of the current collector body 1 and the conductive connector 2, and in the regional weld, there are 2 cutting grooves 4 in the X direction and 2 cutting grooves 4 in the Y direction; in the X direction, the width D of the cutting groove 4 is 10 mm, the interval is 5 mm, and it is centrally distributed; the length C of the cutting groove 4 is 20 mm, the interval is 20 mm, and it is centrally distributed. When the tab is bent, any cutting groove 4 can be selected for bending, which can reduce the space required for bending in the welding area on the one hand, and reduce the risk of tab tearing in the welding area on the other hand.

[0025] In the embodiment: the width A of the weld mark 3 is 60 mm, and the length B is 100 mm; it is centrally distributed at the overlap portion of the current collector body 1 and the conductive connector 2, and in the regional weld, there is one cutting groove 4 in the X direction and four cutting grooves 4 in the Y direction; in the X direction, the width D of the cutting groove 4 is 15 mm, centrally distributed, the length C of the cutting groove 4 is 15 mm, the interval is 5 mm, and it is centrally distributed, and the cutting groove 4 is bent in the weak area, which reduces the space required for bending in the welding area on the one hand, and reduces the risk of ear tearing in the welding area on the other hand.

[0026] The current collector body 1 includes an insulating layer 11 and a first metal layer 12 and a second metal layer 14 respectively coated on both sides of the insulating layer 11. The conductive connecting member 2 includes a first pole tab 13 and a second pole tab 15. The upper and lower surfaces of the current collector body 1 are connected to the first pole tab 13 and the second pole tab 15 through a weld mark 3.

[0027] In the embodiment: the insulating layer 11 is an insulating film, and the material of the insulating film is any one of PMMA, PP, PE, PET, and PI. The first metal layer 12 and the second metal layer 14 are extremely thin metal sheets or strips, such as gold, silver, copper, iron, tin, zinc, lead, nickel, aluminum, tungsten, molybdenum, tantalum, niobium, titanium, steel and stainless steel, nickel-based and cobalt-based alloys, etc., preferably aluminum foil and copper foil. In order to reduce the bendability of the composite current collector, a thin metal layer is coated on both sides of the insulating film. At the pole ear, the metals on both sides are welded together with their respective foil metals. By setting a cutting groove in the weld print area, the cutting groove is a weak area of ​​the welding electrical connection part. When the pole ear is bent, it is preferred to bend in the weak area, which reduces the space required for bending in the welding area on the one hand, and reduces the risk of the pole ear tearing in the welding area on the other hand.

Claims

1. A composite current collector for a secondary battery, characterized in that: The invention comprises a current collector body and a conductive connector, wherein the conductive connectors are overlapped on two opposite sides of the current collector body, a weld mark is arranged at the overlapped part of the current collector body and the conductive connector, and a cutting groove is arranged in the weld mark area.

2. A composite current collector for a secondary battery according to claim 1, characterized in that: The length direction of the current collector body is the X direction, the width direction of the current collector body is the Y direction, the weld mark is rectangular, the width A of the weld mark in the X direction is 0-100 mm, and the length B of the weld mark in the Y direction is 0-500 mm.

3. A composite current collector for a secondary battery according to claim 2, characterized in that: The cutting groove is rectangular. In the welding area, at least one cutting groove is provided. The width of the cutting groove in the X direction is D, and the length in the Y direction is C. D is smaller than A, and C is smaller than B.

4. The composite current collector for a secondary battery according to claim 1, characterized in that: The cutting groove is centrally distributed in the weld imprint area.

5. The composite current collector for a secondary battery according to claim 1, characterized in that: The cutting groove passes through the current collector body and the conductive connecting member.

6. The composite current collector for a secondary battery according to claim 1, characterized in that: The current collector body includes an insulating layer and a first metal layer and a second metal layer respectively coated on both sides of the insulating layer.

7. The composite current collector for a secondary battery according to claim 1, characterized in that: The conductive connecting member comprises a first pole tab and a second pole tab, and the upper and lower surfaces of the current collector body are connected to the first pole tab and the second pole tab by welding.

Images