Lithium battery cover plate assembly and lithium battery

Abstract

The utility model relates to a lithium battery cover plate assembly and a lithium battery, and belongs to the field of new energy power batteries. The lithium battery cover plate assembly comprises a top cover plate structure which is provided with an electrode leading-out hole, and further comprises a terminal structure which comprises a pole and a welding plate, the pole comprises a base part which abuts against one side of the top cover plate structure, and a penetrating part which extends from the base part and penetrates through the electrode lead-out hole; the welding plate is connected with the penetrating portion in a penetrating laser welding mode, and the edge portion of the welding plate abuts against the other side of the top cover plate structure. According to the utility model, through the unique matching design of the terminal structure and the welding plate, the pole and the welding plate can be directly subjected to laser welding, so that the number of structural members is greatly reduced, the difficulty of production and assembly is reduced, the production efficiency is improved, and the production cost is also reduced.

Description

Technical Field

[0001] The utility model relates to the field of new energy power batteries, and in particular to a lithium battery cover plate assembly and a lithium battery. Background Art

[0002] Lithium batteries have the characteristics of high energy density, no memory effect, long single-cell cycle, high efficiency, cleanliness and no pollution. They are widely used in portable electronic products such as mobile phones, laptops, digital cameras, and have good application prospects in electric vehicles and other fields. Especially in recent years, with the vigorous development of the new energy vehicle industry, the new energy vehicle power battery technology industry has also made great and effective development and progress. However, with the more intense competition in the same industry and the significant decline in domestic subsidies for new energy vehicles in recent years, new energy vehicle companies want to occupy the market and ensure survival. They must undoubtedly reduce costs in the manufacture of new energy vehicles, and battery cells are undoubtedly the focus of cost control for car companies.

[0003] In order to optimize and improve the energy density and price cost of the battery cell, the design of the pole structure plays a vital role in the overall battery cell processing process. The existing negative pole material used on the cover plate of the lithium battery shell is often made of copper-aluminum composite material, such as the patent with the authorization announcement number CN107275529B, which discloses a lithium-ion battery negative pole sealing structure and its preparation process. The overall material of the negative pole in this patent is copper-aluminum composite material. The cost of copper-aluminum composite material is very high, and the assembly process is relatively complicated, which cannot meet the demand for reducing the cost of the battery cell. For this reason, there is an urgent need for a cover plate assembly that adopts a specific pole structure, which can ensure the normal conduction of the current while being able to fasten the pole to the cover plate with a simple process method or structural parts. Utility Model Content

[0004] 1. Problems to be solved

[0005] In view of the problem that the copper-aluminum composite material is used as the negative electrode in the prior art, which has high cost and complicated assembly process, the utility model provides a lithium battery cover plate assembly, which adopts a specific pole structure, designs and simplifies the terminal connection structure, and fastens the pole to the end cover with a simple assembly process.

[0006] 2. Technical solution

[0007] To solve the above problems, the utility model adopts the following technical solutions.

[0008] A lithium battery cover plate assembly includes a top cover plate structure, on which an electrode lead-out hole is provided, and also includes: a terminal structure, including a pole and a welding plate; wherein the pole includes a base abutting against one side of the top cover plate structure, and an insertion portion extending from the base through the electrode lead-out hole; the welding plate is connected to the insertion portion by penetrating laser welding, and its edge portion abuts against the other side of the top cover plate structure.

[0009] The lithium battery cover plate assembly of the utility model can directly laser weld the pole and the welding plate through the unique matching design of the terminal structure and the welding plate, which greatly reduces the number of structural parts, reduces the difficulty of production and assembly, improves production efficiency and reduces production costs.

[0010] In some embodiments, the terminal structure includes a positive terminal, and the pole and the welding plate in the positive terminal are both made of aluminum.

[0011] Furthermore, the terminal structure includes a negative terminal, wherein the pole of the negative terminal is made of aluminum and the welding plate is made of copper. The pole of the negative terminal is made of aluminum and the welding plate is made of copper, and the two can be connected together by penetrating laser welding, which simplifies the assembly process compared with the prior art that uses copper-aluminum composite materials as negative pole materials.

[0012] In some embodiments, an insulating member is disposed between the terminal structure and the top cover plate structure, and the insulating member at least wraps a portion of the outer periphery of the base portion and the outer periphery of the insertion portion.

[0013] Furthermore, a seal is provided between the terminal structure and the top cover plate structure, and the seal has a cylindrical portion filling the gap between the insertion portion and the inner wall of the electrode lead-out hole, and an annular portion filling the gap between the top cover plate structure and the welding plate.

[0014] Furthermore, the top cover plate structure includes a base plate abutting against the terminal structure, and a stop frame abutting against the welding plate.

[0015] Furthermore, the stop frame includes a main body, and the main body has an axial limiting portion for limiting the movement of the welding plate toward the axial direction of the pole, and a radial limiting portion for limiting the movement of the welding plate toward the radial direction of the pole.

[0016] In some embodiments, a liquid injection hole is provided on the top cover plate structure.

[0017] Furthermore, an explosion-proof valve is provided on the top cover plate structure.

[0018] A lithium battery comprises a shell with at least one end open, a battery cell is arranged in the shell, and the above-mentioned lithium battery cover plate assembly is arranged at the shell opening.

[0019] It will be apparent that elements or features described above in the context of a single embodiment may be used alone or in combination in other embodiments.

[0020] 3. Beneficial effects

[0021] Compared with the prior art, the beneficial effects of the utility model are:

[0022] (1) The utility model provides a lithium battery cover plate assembly, which can directly laser weld the pole and the welding plate through the unique matching design of the terminal structure and the welding plate, thereby greatly reducing the number of structural parts, reducing the difficulty of production and assembly, improving production efficiency and reducing production costs.

[0023] (2) The utility model provides a lithium battery cover plate assembly, in which the pole of the negative terminal is made of aluminum and the welding plate is made of copper. The two can be connected together by penetrating laser welding, which simplifies the assembly process. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In the drawings, the sizes and proportions do not represent the sizes and proportions of actual products. The drawings are merely illustrative, and some non-essential elements or features are omitted for clarity.

[0025] Figure 1 This is a schematic diagram of the structure of the lithium battery cover assembly in Example 1;

[0026] Figure 2 This is a schematic diagram of the cross-sectional structure of the lithium battery cover assembly in Example 1;

[0027] Figure 3 for Figure 2 The enlarged view of point A in the middle;

[0028] Figure 4 This is a schematic diagram of the structure of the lithium battery cover assembly in Example 1 (I);

[0029] Figure 5 This is a structural schematic diagram of the lithium battery cover assembly in Example 1 (II);

[0030] Figure 6 This is a structural schematic diagram of the lithium battery cover assembly in Example 1 (III).

[0031] Description of Reference Numerals

[0032] 1. Top cover plate structure; 101. Base plate; 102. Stop frame; 1021. Main body; 1022. Axial limiting portion; 1023. Radial limiting portion; 2. Pole; 201. Base; 202. Inserting portion; 3. Welding plate; 4. Sealing member; 401. Cylindrical portion; 402. Annular portion; 5. Insulating member; 6. Liquid injection hole; 7. Explosion-proof valve. DETAILED DESCRIPTION

[0033] The present invention will be described in detail with reference to the accompanying drawings. What is described here is only a preferred embodiment of the present invention, and those skilled in the art can think of other ways to implement the present invention based on the preferred embodiment, and other ways also fall within the scope of the present invention.

[0034] Example 1

[0035] This embodiment provides a lithium battery cover assembly, which is mainly used in secondary batteries, especially lithium batteries. The lithium battery cover assembly can be assembled at the opening of the battery shell, and is suitable for batteries with one end opening as well as batteries with two ends opening.

[0036] like Figure 1-3 As shown, the lithium battery cover plate assembly mainly includes a top cover plate structure 1, a terminal structure assembled on the top cover plate structure 1, and a connecting structure between the two.

[0037] The top cover plate structure 1 includes a substrate 101 and a stop frame 102, both of which are provided with through holes at corresponding positions, which are electrode lead-out holes. The terminal structure includes a pole 2 and a welding plate 3, wherein the pole 2 includes a base 201 abutting against one side of the top cover plate structure 1, specifically, the base 201 abuts against the substrate 101; the pole 2 also includes an insertion portion 202 extending from the base 201 through the electrode lead-out hole. The welding plate 3 is connected to the insertion portion 202 by penetrating laser welding, and its edge portion abuts against the other side of the top cover plate structure 1, specifically, the welding plate 3 abuts against the stop frame 102.

[0038] In a possible embodiment, the terminal structure includes a positive terminal and a negative terminal. The two terminals can be located on the same cover plate, that is, the positive and negative terminals are located at the same end of the battery, and the two terminals can also be located on different cover plates, that is, the positive and negative terminals can also be located at opposite ends of the battery. Among them, the pole 2 and the welding plate 3 in the positive terminal are both made of aluminum, and can be connected by penetrating laser welding without worrying about melting the terminal when the penetrating laser welding temperature is too high. The pole 2 in the negative terminal is made of aluminum, and the welding plate 3 is made of copper. Compared with the copper-aluminum composite material used as the material of the negative pole 2 in the prior art, the copper-aluminum composite material is very expensive and the assembly process is relatively complicated. The special design of the terminal structure in this embodiment can ensure the normal conduction of the current while fastening the pole 2 to the cover plate with a simple process method or structural parts.

[0039] Furthermore, the lithium battery cover plate assembly in this embodiment, through the unique matching design of the terminal structure and the welding plate 3, can directly laser weld the pole 2 and the welding plate 3, which greatly reduces the number of structural parts, reduces the difficulty of production and assembly, improves production efficiency and reduces production costs.

[0040] In order to ensure the insulation effect between the terminal structure and the cover plate structure, in a possible embodiment, an insulating member 5 is provided between the terminal structure and the top cover plate structure 1 , and the insulating member 5 at least wraps a portion of the periphery of the base 201 and the periphery of the insertion portion 202 .

[0041] In order to ensure the sealing effect at the connection between the terminal structure and the cover plate structure, in a possible embodiment, a seal 4 is arranged between the terminal structure and the top cover plate structure 1, and the seal 4 has a cylindrical portion 401 filling the gap between the insertion portion 202 and the inner wall of the electrode lead-out hole, and an annular portion 402 filling the gap between the top cover plate structure 1 and the welding plate 3.

[0042] In order to better connect and support the welding plate 3, in a possible embodiment, the stop frame 102 includes a main body 1021, and the main body 1021 has an axial limiting portion 1022 for limiting the movement of the welding plate 3 in the axial direction of the pole 2, and a radial limiting portion 1023 for limiting the movement of the welding plate 3 in the radial direction of the pole 2.

[0043] Furthermore, if Figure 4-6 As shown, the lithium battery cover plate assembly in this embodiment is further provided with a liquid injection hole 6 and an explosion-proof valve 7 on the top cover plate structure 1.

[0044] Example 2

[0045] This embodiment provides a lithium battery, which is mainly used in new energy power battery modules. Multiple lithium batteries can form a large power battery module to provide power for new energy vehicles and other equipment.

[0046] The lithium battery comprises a shell, at least one end of which is open so that a battery cell can be inserted into the shell. The lithium battery cover assembly in Example 1 is arranged at the opening of the shell, and the connecting piece of the battery cell is electrically connected to the pole 2.

[0047] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "front", "rear", "left", "right", "up", "down", "top", "bottom", "inside" and "outside" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0048] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] The protection scope of the present invention is limited only by the claims. Thanks to the teachings of the present invention, those skilled in the art will easily recognize that alternative structures to the structures disclosed in the present invention can be used as feasible alternative embodiments, and the embodiments disclosed in the present invention can be combined to generate new embodiments, which also fall within the scope of the appended claims.

Claims

1. A lithium battery cover plate assembly, comprising a top cover plate structure (1), wherein the top cover plate structure (1) is provided with an electrode lead-out hole, characterized in that: Also includes: The terminal structure comprises a pole (2) and a welding plate (3); wherein: The pole (2) comprises a base (201) abutting against one side of the top cover plate structure (1), and an insertion portion (202) extending from the base (201) and passing through the electrode lead-out hole; The welding plate (3) is connected to the insertion portion (202) by means of penetrating laser welding, and its edge portion abuts against the other side of the top cover plate structure (1).

2. The lithium battery cover plate assembly according to claim 1, characterized in that: The terminal structure comprises a positive terminal, wherein a pole (2) and a welding plate (3) in the positive terminal are both made of aluminum.

3. The lithium battery cover plate assembly according to claim 1, characterized in that: The terminal structure comprises a negative terminal, wherein the pole (2) of the negative terminal is made of aluminum and the welding plate (3) is made of copper.

4. The lithium battery cover plate assembly according to claim 1, characterized in that: An insulating member (5) is provided between the terminal structure and the top cover plate structure (1), and the insulating member (5) at least wraps a portion of the outer periphery of the base portion (201) and the outer periphery of the insertion portion (202).

5. The lithium battery cover plate assembly according to claim 1, characterized in that: A sealing member (4) is provided between the terminal structure and the top cover plate structure (1), and the sealing member (4) comprises a cylindrical portion (401) filling a gap between the insertion portion (202) and the inner wall of the electrode lead-out hole, and an annular portion (402) filling a gap between the top cover plate structure (1) and the welding plate (3).

6. The lithium battery cover plate assembly according to any one of claims 1 to 5, characterized in that: The top cover plate structure (1) comprises a base plate (101) abutting against the terminal structure, and a stop frame (102) abutting against the welding plate (3).

7. The lithium battery cover plate assembly according to claim 6, characterized in that: The stop frame (102) comprises a main body (1021), and the main body (1021) has an axial limiting portion (1022) for limiting the movement of the welding plate (3) in the axial direction of the pole (2), and a radial limiting portion (1023) for limiting the movement of the welding plate (3) in the radial direction of the pole (2).

8. The lithium battery cover plate assembly according to claim 1, characterized in that: The top cover plate structure (1) is provided with a liquid injection hole (6).

9. The lithium battery cover plate assembly according to claim 1, characterized in that: An explosion-proof valve (7) is provided on the top cover plate structure (1).

10. A lithium battery, comprising a shell with at least one end open, wherein a battery cell is arranged in the shell, characterized in that: The shell opening is provided with a lithium battery cover assembly as described in any one of claims 1 to 9.

Images