Battery assembly and secondary battery

Abstract

The utility model provides a battery assembly and a secondary battery, a negative electrode connecting piece of the battery assembly is a copper-aluminum composite connecting piece, a negative electrode column correspondingly adopts an aluminum negative electrode column made of an aluminum material, when the battery assembly is assembled, a negative electrode lug welding part made of a copper material is welded with a copper negative electrode lug, and a negative electrode column welding part made of an aluminum material is welded with the aluminum negative electrode column. According to the battery assembly, the negative pole does not need to be made into a copper-aluminum composite pole, the usage amount of copper is reduced, the material cost is reduced, the weight is effectively reduced, the welding power parameter is low due to the fact that the negative connecting piece and the negative pole are welded through aluminum materials, welding heating is greatly reduced, and the service life of the battery assembly is prolonged. And the risk of insulation failure is avoided.

Description

Technical Field

[0001] The present application relates to the technical field of power batteries, and in particular to a battery assembly and a secondary battery. Background Art

[0002] In existing power batteries, ultrasonic welding is generally used to connect the pole lugs and adapters, and then laser welding is used to connect the adapters and pole terminals, thereby connecting the core pack inside the battery and the pole terminals. Among them, in the above-mentioned power battery, the positive pole lug is aluminum foil, and the negative pole lug is copper foil. Therefore, in order to ensure that the materials are the same during welding, friction welding is generally used at the negative pole terminal to make a copper-aluminum composite pole, and a positive pole aluminum adapter and a negative pole copper adapter are used to ensure that the welding materials are the same. The copper-aluminum composite pole has a complex shape and processing technology and is relatively expensive; in addition, since the negative connecting piece and the pole are made of copper, the heat generated during welding may cause the plastic under the top cover to melt and deform, posing a risk of insulation failure. Utility Model Content

[0003] The purpose of the embodiments of the present application is to provide a battery assembly and a secondary battery to solve the problem that the existing power battery adopts a copper-aluminum composite pole. Due to the complex shape and processing technology of the copper-aluminum composite pole, the cost is relatively high. In addition, since the negative electrode connecting piece and the pole are made of copper, the heat generated during welding may cause the plastic under the top cover to melt and deform, posing a risk of insulation failure.

[0004] A battery assembly provided in an embodiment of the present application includes: a negative electrode connecting sheet and a top cover;

[0005] The negative electrode connecting piece includes a negative electrode column welding part and a negative electrode ear welding part, wherein the negative electrode column welding part is a plate-shaped structure of aluminum material, and the negative electrode ear welding part is a plate-shaped structure of copper material;

[0006] The top cover includes a top cover substrate and an aluminum negative electrode column; the aluminum negative electrode column is arranged on one side of the top cover substrate;

[0007] The negative electrode ear welding part is welded to the copper negative electrode ear; the negative electrode column welding part is welded to the aluminum negative electrode column by laser penetration welding.

[0008] In the above technical solution, the negative electrode connecting piece of the battery assembly is a copper-aluminum composite connecting piece, and the negative electrode column is an aluminum negative electrode column made of aluminum material. When the battery assembly is assembled, the negative electrode ear welding part of the copper material is welded to the copper negative electrode ear, and the negative electrode column welding part of the aluminum material is welded to the aluminum negative electrode column. The battery assembly of this embodiment does not need to make the negative electrode column into a copper-aluminum composite column, which reduces the use of copper, reduces material costs and effectively reduces weight. In addition, since the welding of the negative electrode connecting piece and the negative electrode column is the welding of aluminum material and aluminum material, the required welding power parameters are relatively low, which greatly reduces welding heat and avoids the risk of insulation failure.

[0009] In some optional embodiments, a groove is formed in the middle of the negative electrode ear welding part to form an upper plate and a lower plate that are symmetrical up and down; the upper plate and the lower plate of the negative electrode ear welding part are welded to the copper negative electrode ear by butterfly welding.

[0010] In the above technical solution, the negative electrode connecting piece includes an upper plate and a lower plate that are symmetrical in both directions to achieve butterfly welding with the pole ear. Butterfly welding, also known as the lithium battery butterfly welding process, has higher reliability and lower risk of desoldering and short circuit than the traditional wire connection method.

[0011] In some optional embodiments, a positioning hole is provided at the center of the negative electrode column welding portion, and the positioning hole is used to assist positioning during the assembly process.

[0012] In the above technical solution, the positioning hole is used as an assembly reference to effectively improve the positioning accuracy between the negative electrode column and the negative electrode connecting piece. Through the positioning hole, the negative electrode column and the negative electrode connecting piece can be accurately aligned before welding, and deformation and displacement during welding can be prevented, thereby ensuring the stability and accuracy of the workpiece after welding.

[0013] In some optional embodiments, the top cover further comprises a lower plastic, and a limiting column is arranged on the lower plastic;

[0014] The negative electrode connecting piece also includes: a connecting portion between the negative electrode column welding portion and the negative electrode ear welding portion; the connecting portion is an asymmetric structure, and the upper side or the lower side of the connecting portion cooperates with the limiting column, which is used to prevent the negative electrode connecting piece from being installed upside down during assembly.

[0015] In the above technical solution, the asymmetric design of the negative electrode connector can effectively avoid misoperation during the assembly process, especially on the automated assembly line. This design can significantly reduce the risk of reverse installation, thereby improving the safety of the battery. The setting of the limit column further enhances this safety. Through physical restrictions, it prevents the reverse insertion of the negative electrode connector during assembly, avoiding safety hazards such as short circuits caused by reverse installation. In addition, the limit column can ensure that the position of the negative electrode connector in the top cover is fixed, preventing performance degradation or damage that may be caused by position changes. The connector with an asymmetric structure is easier to identify and locate on the automated assembly line, reducing the difficulty of assembly and improving production efficiency. The design of the limit column also simplifies the assembly process, reduces the time for manual inspection and adjustment, and further improves production efficiency.

[0016] In some optional embodiments, it further includes: a positive electrode connecting sheet;

[0017] The positive electrode connecting piece includes a positive electrode column welding portion and a positive electrode ear welding portion, and the positive electrode column welding portion and the positive electrode ear welding portion are an integrally formed aluminum plate structure.

[0018] In some optional embodiments, the top cover further includes an aluminum positive electrode column; the aluminum positive electrode column is disposed on a side of the top cover substrate away from the aluminum negative electrode column;

[0019] The positive electrode ear welding part is welded to the aluminum positive electrode ear; the positive electrode column welding part is welded to the aluminum positive electrode column by laser penetration welding.

[0020] In some optional embodiments, a groove is formed in the middle of the positive electrode tab welding part to form an upper plate and a lower plate that are symmetrical up and down; the upper plate and the lower plate of the positive electrode tab welding part are welded to the aluminum positive electrode tab by butterfly welding.

[0021] In the above technical solution, the positive electrode connecting piece includes an upper plate and a lower plate which are symmetrical in vertical direction to realize butterfly welding with the pole ear.

[0022] In some optional embodiments, a positioning hole is provided at the center of the positive electrode column welding portion, and the positioning hole is used to assist positioning during the assembly process.

[0023] In the above technical solution, the positioning hole is used as an assembly reference to effectively improve the positioning accuracy between the positive electrode column and the positive connecting piece. Through the positioning hole, the positive electrode column and the positive connecting piece can be accurately aligned before welding, and deformation and displacement during welding can be prevented, thereby ensuring the stability and accuracy of the workpiece after welding.

[0024] In some optional embodiments, the top cover further comprises a lower plastic, and a limiting column is arranged on the lower plastic;

[0025] The positive electrode connecting piece also includes a connecting portion between the positive electrode column welding portion and the positive electrode ear welding portion, and the positive electrode column welding portion, the positive electrode ear welding portion and the connecting portion are integrally formed; the connecting portion is an asymmetric structure up and down, and the upper side or the lower side of the connecting portion cooperates with the limit column, and the limit column is used to prevent the positive electrode connecting piece from being installed upside down during assembly.

[0026] In the above technical solution, the asymmetric positive electrode connector design can effectively avoid misoperation during the assembly process, especially on the automated assembly line. This design can significantly reduce the risk of reverse installation, thereby improving the safety of the battery. The setting of the limit column further enhances this safety. Through physical restrictions, it prevents the reverse insertion of the positive electrode connector during assembly, avoiding safety hazards such as short circuits caused by reverse installation. In addition, the limit column can ensure that the position of the positive electrode connector in the top cover is fixed, preventing performance degradation or damage that may be caused by position changes. The connector with an asymmetric structure is easier to identify and locate on the automated assembly line, reducing the difficulty of assembly and improving production efficiency. The design of the limit column also simplifies the assembly process, reduces the time for manual inspection and adjustment, and further improves production efficiency.

[0027] A secondary battery provided in an embodiment of the present application includes a battery assembly as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 A schematic diagram of a battery assembly structure provided in an embodiment of the present application;

[0030] Figure 2 A schematic diagram of the structure of the negative electrode connecting piece provided in the first embodiment of the present application;

[0031] Figure 3 A schematic diagram of the structure of the negative electrode connecting piece provided in the second embodiment of the present application;

[0032] Figure 4 A schematic diagram of the structure of the negative electrode connecting piece provided in the third embodiment of the present application;

[0033] Figure 5 A schematic diagram of the structure of the negative electrode connecting piece provided in the fourth embodiment of the present application;

[0034] Figure 6 A schematic diagram of a secondary battery structure provided in an embodiment of the present application.

[0035] Icon: 1-negative electrode connecting piece, 11-negative electrode ear welding part, 111-lower plate, 12-negative electrode column welding part, 121-positioning hole, 13-connecting part, 2-top cover, 21-top cover substrate, 22-aluminum negative electrode column, 23-lower plastic, 24-upper plastic. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0037] Please refer to Figure 1 , Figure 1 A schematic diagram of a battery assembly structure provided in an embodiment of the present application specifically includes: a negative electrode connecting piece 1 and a top cover 2. Among them, the negative electrode connecting piece 1 includes a negative electrode column welding part 12 and a negative electrode ear welding part 11, the negative electrode column welding part 12 is a plate-like structure of aluminum material, and the negative electrode ear welding part 11 is a plate-like structure of copper material; the top cover 2 includes a top cover substrate 21 and an aluminum negative electrode column 22; the aluminum negative electrode column 22 is arranged on one side of the top cover substrate 21; the negative electrode ear welding part 11 is welded to the copper negative electrode ear; the negative electrode column welding part 12 is welded to the aluminum negative electrode column 22 by laser penetration welding.

[0038] In the embodiment of the present application, the negative electrode connecting piece 1 of the battery assembly is a copper-aluminum composite connecting piece, and the negative electrode column correspondingly adopts an aluminum negative electrode column 22 made of aluminum material. When the battery assembly is assembled, the negative electrode ear welding part 11 of the copper material is welded to the copper negative electrode ear, and the negative electrode column welding part 12 of the aluminum material is welded to the aluminum negative electrode column 22. The negative electrode column of the battery assembly of this embodiment is made of all-aluminum material (for example, Al 1060-H14), and there is no need to make the negative electrode column into a copper-aluminum composite column, which reduces the use of copper, reduces material costs and effectively reduces weight. In addition, since the welding of the negative electrode connecting piece 1 and the negative electrode column is the welding of aluminum material and aluminum material, the required welding power parameters are low, which greatly reduces welding heat and avoids the risk of insulation failure.

[0039] For details, please refer to Figure 2 , Figure 2 This is a schematic diagram of the structure of the negative electrode connecting sheet 1 provided in the first embodiment of the present application. The negative electrode connecting sheet 1 includes a negative electrode column welding portion 12 and a negative electrode ear welding portion 11. The negative electrode column welding portion 12 and the negative electrode ear welding portion 11 can be compositely formed by casting and rolling.

[0040] In some optional embodiments, the negative electrode ear welding part 11 is slotted in the middle to form an upper plate and a lower plate 111 that are symmetrical up and down; the upper plate and the lower plate 111 of the negative electrode ear welding part 11 are welded to the copper negative electrode ear by butterfly welding. Figure 3 and Figure 4 , Figure 3 This is a schematic diagram of the structure of the negative electrode connecting sheet 1 provided in the second embodiment of the present application. Figure 4This is a schematic structural diagram of the negative electrode connecting piece 1 provided in the third embodiment of the present application.

[0041] In the embodiment of the present application, the negative electrode connecting sheet 1 includes an upper plate and a lower plate 111 that are symmetrical in both directions to achieve butterfly welding with the pole ear. Butterfly welding, also known as lithium battery butterfly welding process, has higher reliability and lower risk of desoldering and short circuit compared to traditional wire connection methods.

[0042] Please refer to Figure 5 , Figure 5 This is a schematic structural diagram of the negative electrode connecting piece 1 provided in the fourth embodiment of the present application.

[0043] In some optional embodiments, a positioning hole 121 is provided at the center of the negative electrode column welding portion 12, and the positioning hole 121 is used to assist positioning during assembly. In the embodiment of the present application, the positioning hole 121 is used as an assembly reference to effectively improve the positioning accuracy between the negative electrode column and the negative electrode connecting piece 1. Through the positioning hole 121, it is possible to ensure that the positions of the negative electrode column and the negative electrode connecting piece 1 are accurately aligned before welding, and to prevent deformation and displacement during welding, thereby ensuring the stability and accuracy of the workpiece after welding.

[0044] In some optional embodiments, the top cover 2 also includes a lower plastic 23, on which a limiting column is arranged; the negative electrode connecting piece 1 also includes: a connecting portion 13 between the negative electrode column welding portion 12 and the negative electrode ear welding portion 11; the connecting portion 13 is an asymmetric structure up and down, and the upper side or the lower side of the connecting portion 13 cooperates with the limiting column, and the limiting column is used to prevent the negative electrode connecting piece 1 from being installed upside down during assembly.

[0045] In the embodiment of the present application, the asymmetric design of the negative electrode connector 1 can effectively avoid misoperation during the assembly process, especially on the automated assembly line. This design can significantly reduce the risk of reverse installation, thereby improving the safety of the battery. The setting of the limit column further enhances this safety, and prevents the reverse insertion of the negative electrode connector 1 during assembly through physical restrictions, thereby avoiding safety hazards such as short circuits caused by reverse installation. In addition, the limit column can ensure that the position of the negative electrode connector 1 in the top cover 2 is fixed, preventing performance degradation or damage that may be caused by position changes. The connector with an asymmetric structure is easier to identify and locate on the automated assembly line, reducing the difficulty of assembly and improving production efficiency. The design of the limit column also simplifies the assembly process, reduces the time for manual inspection and adjustment, and further improves production efficiency.

[0046] In some optional embodiments, it also includes: a positive electrode connecting piece; the positive electrode connecting piece includes a positive electrode column welding part and a positive electrode ear welding part, and the positive electrode column welding part and the positive electrode ear welding part are an integrally formed aluminum material plate structure.

[0047] In some optional embodiments, the top cover 2 also includes an aluminum positive electrode column; the aluminum positive electrode column is arranged on the side of the top cover substrate 21 away from the aluminum negative electrode column 22; the positive electrode ear welding part is welded to the aluminum positive electrode ear; the positive electrode column welding part is welded to the aluminum positive electrode column by laser penetration welding.

[0048] In some optional embodiments, a groove is formed in the middle of the positive electrode ear welding part to form an upper plate and a lower plate 111 that are symmetrical up and down; the upper plate and the lower plate 111 of the positive electrode ear welding part are welded to the aluminum positive electrode ear by butterfly welding. In the embodiment of the present application, the positive electrode connecting piece includes an upper plate and a lower plate 111 that are symmetrical up and down to achieve butterfly welding with the electrode ear.

[0049] In some optional embodiments, a positioning hole 121 is provided at the center of the positive electrode column welding portion, and the positioning hole 121 is used to assist positioning during the assembly process. In the embodiment of the present application, the positioning hole 121 is used as an assembly reference to effectively improve the positioning accuracy between the positive electrode column and the positive electrode connecting piece. Through the positioning hole 121, it is possible to ensure that the positive electrode column and the positive electrode connecting piece are accurately aligned before welding, and to prevent deformation and displacement during the welding process, thereby ensuring the stability and accuracy of the workpiece after welding.

[0050] In some optional embodiments, the top cover 2 also includes a lower plastic 23 and an upper plastic 24, and a limiting column is arranged on the lower plastic 23; the positive electrode connecting piece also includes a connecting portion 13 between the positive electrode column welding portion and the positive electrode ear welding portion, and the positive electrode column welding portion, the positive electrode ear welding portion and the connecting portion 13 are integrally formed; the connecting portion 13 is an asymmetric structure up and down, and the upper side or the lower side of the connecting portion 13 cooperates with the limiting column, and the limiting column is used to prevent the positive electrode connecting piece from being installed upside down during assembly.

[0051] In the embodiment of the present application, the asymmetric positive electrode connector design can effectively avoid misoperation during the assembly process, especially on the automated assembly line. This design can significantly reduce the risk of reverse installation, thereby improving the safety of the battery. The setting of the limit column further enhances this safety, and prevents the reverse insertion of the positive electrode connector during assembly through physical restrictions, avoiding safety hazards such as short circuits caused by reverse installation. In addition, the limit column can ensure that the position of the positive electrode connector in the top cover 2 is fixed, preventing performance degradation or damage that may be caused by position changes. The connector with an asymmetric structure is easier to identify and locate on the automated assembly line, reducing the difficulty of assembly and improving production efficiency. The design of the limit column also simplifies the assembly process, reduces the time for manual inspection and adjustment, and further improves production efficiency.

[0052] Please refer to Figure 6 , Figure 6 A schematic diagram of the structure of a secondary battery provided in an embodiment of the present application, the secondary battery includes a battery assembly as described above.

[0053] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0054] In addition, the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0055] Furthermore, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0056] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0057] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery assembly, characterized in that: include: Negative electrode connecting piece and top cover; The negative electrode connecting piece comprises a negative electrode column welding portion and a negative electrode ear welding portion, wherein the negative electrode column welding portion is a plate-shaped structure of aluminum material, and the negative electrode ear welding portion is a plate-shaped structure of copper material; The top cover comprises a top cover substrate and an aluminum negative electrode column; the aluminum negative electrode column is arranged on one side of the top cover substrate; The negative electrode ear welding portion is welded to the copper negative electrode ear; the negative electrode column welding portion is welded to the aluminum negative electrode column by laser penetration welding.

2. The battery assembly according to claim 1, characterized in that The negative electrode ear welding part has a groove in the middle to form an upper plate and a lower plate that are symmetrical up and down; the upper plate and the lower plate of the negative electrode ear welding part are welded to the copper negative electrode ear by butterfly welding.

3. The battery assembly according to claim 1, characterized in that A positioning hole is arranged at the center of the negative electrode column welding portion, and the positioning hole is used for auxiliary positioning during the assembly process.

4. The battery assembly according to claim 1, wherein: The top cover also includes a lower plastic, and a limiting column is arranged on the lower plastic; The negative electrode connecting piece also includes: a connecting portion between the negative electrode column welding portion and the negative electrode ear welding portion; the connecting portion is an asymmetric structure, and the upper side or the lower side of the connecting portion cooperates with the limiting column, and the limiting column is used to prevent the negative electrode connecting piece from being installed upside down during assembly.

5. The battery assembly according to claim 1, characterized in that: Also includes: Positive electrode connecting piece; The positive electrode connecting piece includes a positive electrode column welding portion and a positive electrode ear welding portion, and the positive electrode column welding portion and the positive electrode ear welding portion are an integrally formed aluminum material plate structure.

6. The battery assembly according to claim 5, characterized in that: The top cover also includes an aluminum positive electrode column; the aluminum positive electrode column is arranged on a side of the top cover substrate away from the aluminum negative electrode column; The positive electrode ear welding portion is welded to the aluminum positive electrode ear; the positive electrode column welding portion is welded to the aluminum positive electrode column by laser penetration welding.

7. The battery assembly according to claim 6, characterized in that: The positive electrode ear welding part has a groove in the middle to form an upper plate and a lower plate that are symmetrical up and down; the upper plate and the lower plate of the positive electrode ear welding part are welded to the aluminum positive electrode ear by butterfly welding.

8. The battery assembly according to claim 6, characterized in that: A positioning hole is arranged at the center of the positive electrode column welding portion, and the positioning hole is used for auxiliary positioning during the assembly process.

9. The battery assembly according to claim 6, characterized in that: The top cover also includes a lower plastic, and a limiting column is arranged on the lower plastic; The positive electrode connecting piece also includes a connecting portion between the positive electrode column welding portion and the positive electrode ear welding portion, and the positive electrode column welding portion, the positive electrode ear welding portion and the connecting portion are integrally formed; the connecting portion is an asymmetric structure up and down, and the upper side or the lower side of the connecting portion cooperates with the limiting column, and the limiting column is used to prevent the positive electrode connecting piece from being installed upside down during assembly.

10. A secondary battery, characterized in that: Comprising a battery assembly as described in any one of claims 1 to 9.

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