A novel cylindrical battery structure

Abstract

This utility model discloses a novel cylindrical battery structure, relating to the field of power lithium battery technology. It includes an aluminum shell, with a negative electrode top cover assembly and a positive current collector mounted at the top and bottom of the shell, respectively. An integrally formed explosion-proof valve is located at the bottom of the aluminum shell, with grooves forming a thinned area to create a pressure relief channel. This battery employs a single-pole riveting structure, placing the explosion-proof valve integrally at the bottom of the aluminum shell, eliminating the need to weld the explosion-proof valve into the negative electrode top cover assembly. This increases the height space of the electrode tabs, improving welding and sealing reliability. The positive current collector is welded to the aluminum shell through the bottom, reducing the risk of leakage, increasing resistance to compression, and decreasing internal resistance compared to traditional open seam welding.

Description

Technical Field

[0001] This utility model belongs to the field of power lithium battery technology, and specifically relates to a novel cylindrical battery structure. Background Technology

[0002] With the rapid development of the new energy industry, power lithium batteries, especially cylindrical batteries, are increasingly widely used in electric vehicles, energy storage and other fields due to their high energy density and strong adaptability.

[0003] However, existing cylindrical battery structures have significant shortcomings in safety and stability: in traditional top-cover components, the explosion-proof valve needs to be fixed to the casing by welding, which is prone to insufficient airtightness due to poor welding or incomplete welding, thus creating a risk of thermal runaway; the positive electrode current collector often uses a top-opening seam welding process, which not only increases the sealing difficulty but also prolongs the current path, leading to increased internal resistance. These problems severely restrict the application of cylindrical batteries in high-safety, long-life scenarios, and there is an urgent need for innovative optimization of the top cover and casing structure. Utility Model Content

[0004] In view of the problems mentioned in the background art, the purpose of this utility model is to provide a new cylindrical battery structure to solve the problems mentioned in the background art.

[0005] The above-mentioned technical objective of this utility model is achieved through the following technical solution:

[0006] A novel cylindrical battery structure includes an aluminum casing. A negative electrode top cover assembly and a positive current collector are respectively installed at the top and bottom of the aluminum casing. An integrally formed explosion-proof valve is provided at the bottom of the aluminum casing. The explosion-proof valve has a thinning area formed by scribing at the bottom of the aluminum casing, which constitutes a pressure relief channel.

[0007] Preferably, the groove depth of the explosion-proof valve is 30%-50% of the aluminum shell wall thickness.

[0008] Preferably, the groove shape of the explosion-proof valve includes annular, cross-shaped, or star-shaped.

[0009] Preferably, an explosion-proof patch is attached to the bottom of the aluminum shell, and the explosion-proof valve is located within the coverage area of ​​the explosion-proof patch.

[0010] Preferably, the positive current collector is laser-welded to the inner wall of the bottom end of the aluminum shell and is connected to the positive electrode tab of the battery cell inside the aluminum shell.

[0011] Preferably, the negative electrode top cover assembly includes a top cover plate, a negative electrode post, and a negative current collector. The top cover plate is welded to the inner wall of the top of the aluminum shell. The negative electrode post riveted to the top cover plate is connected to the negative current collector. The negative current collector is connected to the negative electrode tab inside the aluminum shell. The height space between the negative current collector and the negative electrode tab is not less than 8mm.

[0012] This utility model proposes a novel cylindrical battery structure that employs a single-pole riveting structure. The explosion-proof valve is integrally formed at the bottom of the aluminum shell, eliminating the need to weld the explosion-proof valve into the negative electrode top cover assembly. This increases the height space of the electrode tabs, thereby improving welding and sealing reliability. The positive current collector is welded to the aluminum shell through the bottom of the aluminum shell. Compared with traditional open seam welding, this reduces the risk of leakage, increases the resistance to extrusion, and reduces internal resistance.

[0013] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0014] Figure 1 This invention proposes a novel three-dimensional structure for a cylindrical battery. Figure 1 ;

[0015] Figure 2 This invention proposes a novel three-dimensional structure for a cylindrical battery. Figure 2 ;

[0016] Figure 3 This is a bottom view of a novel cylindrical battery structure proposed in this utility model;

[0017] Figure 4 for Figure 3 Perspective view and enlarged view along the AA direction.

[0018] Reference numerals: 1. Negative electrode top cover assembly; 11. Injection port; 12. Negative electrode post; 13. Upper plastic; 14. Top cover plate; 15. Extension plate; 16. Negative current collector; 2. Positive current collector; 3. Aluminum shell; 31. Explosion-proof grooves. Detailed Implementation

[0019] The embodiments of this utility model are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar symbols denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0020] Example 1

[0021] refer to Figures 1 to 4 The novel cylindrical battery described in this embodiment includes an aluminum shell 3. A negative electrode top cover assembly 1 and a positive current collector 2 are respectively installed at the top and bottom of the aluminum shell 3. An integrally formed explosion-proof valve 31 is provided at the bottom of the aluminum shell 3. The explosion-proof valve 31 has a thinning area formed by etched grooves at the bottom of the aluminum shell 3, which constitutes a pressure relief channel.

[0022] Preferably, the groove depth of the explosion-proof valve 31 is 30%-50% of the wall thickness of the aluminum shell 3. If the groove is too deep, it is easy to leak liquid; if the groove is too shallow, it is easy to fail to explode and thus fail to achieve the purpose of explosion protection.

[0023] Preferably, the explosion-proof valve 31 is engraved on the outer wall of the aluminum shell 3 with the opening facing downwards for easy engraving.

[0024] Preferably, the groove shape of the explosion-proof valve 31 includes annular, cross-shaped, or star-shaped, symmetrical structure, which can uniformly regulate local stress and improve the pressure relief response speed.

[0025] An explosion-proof patch is affixed to the bottom of the aluminum shell 3, and the explosion-proof valve 31 is located within the coverage area of ​​the explosion-proof patch. After the explosion-proof valve 31 is scored, the explosion-proof patch is affixed to the bottom of the aluminum shell 3 to protect the explosion-proof valve 31.

[0026] The positive current collector 2 is laser-penetrating welded to the inner wall of the bottom end of the aluminum shell 3 and is connected to the positive electrode tab of the battery cell inside the aluminum shell 3. During assembly, the positive current collector 2 is inserted into the aluminum shell 3 through the opening and then laser-penetrating welded to the bottom end of the aluminum shell 3.

[0027] The negative electrode top cover assembly 1 includes a top cover plate 14, a negative electrode post 12 and a negative current collector 16. The top cover plate 14 is welded to the inner wall of the top of the aluminum shell 3. An unobstructed vertical space channel is formed between the top cover plate 14 and the positive current collector 2. The negative electrode post 12 riveted to the top cover plate 14 is connected to the negative current collector 16.

[0028] The height of the vertical space channel is not less than 8mm. Compared with the traditional battery cover structure, the battery in this structure places the explosion-proof valve 31 at the bottom of the battery, eliminating the explosion-proof valve, insulating sheet and other multi-layer components in the cover assembly, simplifying the cover structure, forming an unobstructed vertical space channel, increasing the extension space of the negative electrode post 12 and improving the reliability of welding.

[0029] Specifically, the top cover plate 14 has an injection port 11. After the injection is completed, a sealing rubber plug is inserted into the injection port 11, and a sealing patch is welded into the injection port 11 at the top of the sealing rubber plug.

[0030] A disc-shaped upper plastic 13 is installed on the top cover plate 14. The negative terminal 12 is riveted to the upper plastic 13 and passes through the upper plastic 13 and the top cover plate 14. The upper plastic 13 forms a seal between the negative terminal 12 and the top cover plate 14.

[0031] An extension piece 15 is welded to the bottom of the negative electrode post 12. The extension piece 15 is welded to the negative current collector 16. The negative current collector 16 is connected to the negative electrode tab inside the aluminum shell 3.

[0032] The battery structure adopts a single-pole riveting structure, with the explosion-proof valve 31 integrally formed at the bottom of the aluminum shell 3. This eliminates the need to weld the explosion-proof valve in the negative electrode top cover assembly 1, increasing the height space of the electrode tab and improving the reliability of welding and sealing. The positive current collector is welded to the aluminum shell 3 through the bottom of the aluminum shell 3. Compared with the traditional open seam welding, this reduces the risk of leakage, increases the resistance to extrusion, and reduces the internal resistance.

[0033] It should be understood that the terms "length", "thickness", "upper", "lower", "inner", "outer", "axial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0035] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0036] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0037] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A novel cylindrical battery structure, comprising an aluminum casing (3), characterized in that: The top and bottom of the aluminum shell (3) are respectively equipped with a negative electrode top cover assembly (1) and a positive current collector (2). The bottom of the aluminum shell (3) is provided with an integrally formed explosion-proof valve (31). The explosion-proof valve (31) is scored at the bottom of the aluminum shell (3) to form a thinning area, which constitutes a pressure relief channel. The negative electrode top cover assembly (1) includes a top cover plate (14), a negative electrode post (12) and a negative current collector (16). The top cover plate (14) is welded to the inner wall of the top of the aluminum shell (3). The negative electrode post (12) riveted to the top cover plate (14) is connected to the negative current collector (16). The negative current collector (16) is connected to the negative electrode ear inside the aluminum shell (3). The height space between the negative current collector (16) and the negative electrode ear is not less than 8mm.

2. The novel cylindrical battery structure according to claim 1, characterized in that: The depth of the groove on the explosion-proof valve (31) is 30%-50% of the wall thickness of the aluminum shell (3).

3. The novel cylindrical battery structure according to claim 1, characterized in that: The groove shapes of the explosion-proof valve (31) include ring, cross, or star shapes.

4. The novel cylindrical battery structure according to claim 1, characterized in that: An explosion-proof patch is attached to the bottom of the aluminum shell (3), and the explosion-proof valve (31) is located within the coverage area of ​​the explosion-proof patch.

5. The novel cylindrical battery structure according to claim 1, characterized in that: The positive current collector (2) is laser-welded to the inner wall of the bottom end of the aluminum shell (3) and is connected to the positive electrode tab of the inner cell of the aluminum shell (3).

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