Battery case

Abstract

A battery case, comprising: a housing (1), an opening being provided at the top of the housing (1); and a top cover (2), which comprises a cover body (21), wherein the top cover (2) further comprises a flange (22) connected to the edge of the cover body (21), and the flange (22) is welded to the housing (1) so as to jointly block the opening with the cover body (21). The flange (22) has a first top portion and a first bottom portion opposite each other, and the cover body (21) has a second top portion and a second bottom portion opposite each other, wherein the distance between the first top portion and the first bottom portion is greater than the distance between the second top portion and the second bottom portion, and the first bottom portion is provided with a guide portion.

Description

A battery box

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 27, 2023, with application number 202323592653.7. The entire contents of the above application are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a battery box. Background Art

[0003] Lithium batteries have the advantages of small size, high energy density, long service life, and green environmental protection. They are widely used in industries such as automobiles, electronic products, and energy storage systems. SUMMARY OF THE INVENTION

[0004] Currently, the cover of the box that holds the battery core pack is gradually becoming thinner, which makes it very easy to weld through the cover when laser welding it to the aluminum shell, causing the laser to penetrate directly onto the core pack and affect the performance of the core pack.

[0005] Therefore, it is urgent to design a battery box to solve the technical hidden dangers.

[0006] The present application provides a battery case, comprising: a shell, the top of which is provided with an opening; a top cover, comprising a cover body; wherein the top cover also includes a boss connected to the edge of the cover body, the boss being welded to the shell to seal the opening together with the cover body; the boss has a first top and a first bottom relative to each other, the cover body has a second top and a second bottom relative to each other, the distance between the first top and the first bottom is greater than the distance between the second top and the second bottom, and the first bottom is provided with a guide portion. Beneficial effects

[0007] The battery case provided in the present application is configured such that a boss is provided on the edge of the cover body, and the distance between the first top and the first bottom of the boss is greater than the distance between the second top and the second bottom of the cover body, thereby increasing the contact area between the top cover and the shell, making it difficult to penetrate the top cover during welding, protecting the core package from being affected by the laser, and achieving an ideal penetration depth after welding, so that the top cover and the shell have better tensile strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG1 is a partial cross-sectional view of a battery case provided in Examples 1 and 2;

[0009] FIG2 is a partial cross-sectional view of a battery case provided in Example 3, showing the arc-shaped groove at the bottom of the groove;

[0010] FIG3 is a partial cross-sectional view of a battery case provided in Example 3, for illustrating a triangular groove;

[0011] FIG4 is a partial cross-sectional view of a battery case provided in Example 3, for illustrating the trapezoidal groove;

[0012] FIG5 is a partial cross-sectional view of a battery case provided in Example 4;

[0013] FIG6 is a partial cross-sectional view of a battery case provided in Example 5;

[0014] Description of reference numerals:

[0015] 1. Shell; 2. Top cover; 21. Cover body; 22. Boss; 221. First extension portion; 222. Bend portion; 223. Second extension portion; 224. Guide surface; 225. Groove; 3. Welding surface. Modes for Carrying Out the Invention

[0016] Example 1

[0017] 1 , an embodiment of the present application provides a battery box, comprising:

[0018] Shell 1, the top of the shell 1 is provided with an opening;

[0019] Top cover 2, including a cover body 21;

[0020] Among them, the top cover 2 also includes a boss 22 connected to the edge of the cover body 21, and the boss 22 is welded to the shell 1 to seal the opening together with the cover body 21; the boss 22 has a relative first top and first bottom, and the cover body 21 has a relative second top and second bottom. The distance between the first top and the first bottom of the boss 22 is greater than the distance between the second top and the second bottom of the cover body 21, and the first bottom of the boss 22 is provided with a guide portion.

[0021] By arranging a boss 22 on the edge of the cover body 21 and making the distance between the first top and the first bottom of the boss 22 greater than the distance between the second top and the second bottom of the cover body 21, the contact area between the top cover 2 and the shell 1 is increased, making it difficult to penetrate the top cover 2 during the welding process, protecting the core package from being affected by the laser, and achieving an ideal penetration depth after welding, so that the top cover 2 and the shell 1 have better tensile strength.

[0022] Example 2

[0023] 1 , an embodiment of the present application provides a battery case including a shell 1 and a top cover 2 .

[0024] The top of the housing 1 is provided with an opening. A top cover 2 is used to seal the opening. The top cover 2 comprises an integrally formed cover body 21 and a boss 22 connected to the edge of the cover body 21. The boss 22 is welded to the side wall of the housing 1, and the contact surface between the boss 22 and the housing 1 is a welding surface 3.

[0025] The boss 22 has a first top and a first bottom facing each other, and the cover 21 has a second top and a second bottom facing each other. The first top of the boss 22 is flush with the second top of the cover 21, and the first bottom of the boss 22 is located below the second bottom of the cover 21. That is, in the direction from the first top to the first bottom, the thickness of the boss 22 is 1-5 mm thicker than that of the cover 21.

[0026] The first bottom portion of boss 22 is provided with a guide portion having a guide surface 224 near the weld between boss 22 and housing 1. The distance between guide surface 224 and the sidewall of housing 1 increases from the first top portion toward the first bottom portion, and the angle between guide surface 224 and the sidewall of housing 1 is between 30 and 60 degrees. Guide surface 224 facilitates insertion of top cover 2 into the opening of housing 1, facilitating assembly.

[0027] Example 3

[0028] The difference from Example 2 is that, referring to Figures 2, 3, and 4, a groove 225 is provided on the first top portion of the boss 22. The groove 225 faces the sidewall of the housing 1, and the distance between the groove 225 and the welding surface 3 is zero. The groove 225 accommodates the melt produced when welding the top cover 2 to the housing 1, reducing the excess height after welding the top cover 2 and the housing 1, and improving the flatness of the top of the battery case. In this embodiment, the edge of the top cover 2 is bent downward to form the cover 21 and the boss 22. A guide surface 224 is formed on the first bottom portion of the boss 22 by machining. The rounded corner formed by the partial stretching of the top cover 2 during the bending process serves as the groove 225, and the bottom of the groove 225 is curved. Alternatively, the boss 22 and the cover 21 can be formed through other molding processes, and the groove 225 can be additionally machined. The shape of the groove 225 can be triangular or trapezoidal, for example. The depth of the groove 225 is preferably between 0.3 mm and 1 mm, proportional to the thickness of the top cover 2.

[0029] In the direction from the first top to the first bottom, preferably, the length of the welding surface 3 is 1 mm to 5 mm longer than the thickness of the cover body 21 .

[0030] Example 4

[0031] The difference from Example 3 is that, referring to Figure 5 , the boss 22 includes a bent portion 222 and a first extension portion 221 and a second extension portion 223 disposed opposite each other. The first extension portion 221 is located between the second extension portion 223 and the cover 21 and is attached to the second extension portion 223. The top of the first extension portion 221 is bent and connected to the edge of the cover 21. The bottom of the first extension portion 221 is located below the bottom of the cover 21. The bent portion 222 is connected between the bottom of the first extension portion 221 and the bottom of the second extension portion 223. The top of the second extension portion 223, the housing 1, and the top of the first extension portion 221 form a groove 225. A guide surface 224 is formed on the bent portion 222. In this embodiment, the contact surface between the second extension portion 223 and the side wall of the housing 1 is a welding surface 3. The first extension 221, the bent portion 222, and the second extension 223 are formed in sequence by two bends, and the depth of the groove 225 is adjusted by controlling the length of the second extension 223. Due to process characteristics, the guide surface 224 in this embodiment is arc-shaped and the bent portion 222 is a U-shaped structure.

[0032] Example 5

[0033] The difference from Example 4 is that, referring to Figure 6 , the top of the first extension 221, the top of the second extension 223, and the bent portion 222 form the groove 225. In actual production, the first extension 221, the bent portion 222, and the second extension 223 are sequentially formed through three bends. Furthermore, a distance is provided between the groove 225 and the welding surface 3. The distance between the groove 225 and the welding surface 3 is ≤ 2 mm, allowing the groove 225 to be as close as possible to the welding surface 3 to accommodate the melt produced by welding. In this embodiment, the guide surface 224 formed on the bent portion 222 can be either an arc or a plane. When the guide surface 224 is a plane, the angle between the guide surface 224 and the side wall of the housing 1 is between 30 and 60 degrees.

[0034] In this embodiment, the first extension portion 221, the bent portion 222 and the second extension portion 223 can also be obtained by stamping the edge of the top cover 2. By stamping in a direction perpendicular to the top cover 2, part of the material flows to both sides to form the first extension portion 221 and the second extension portion 223. The groove left by the final stamping is the groove 225 for accommodating the melt.

Claims

1. A battery box body, comprising: A housing (1), with an opening provided at the top of the housing (1); A top cover (2), including a cover body (21); Wherein, the top cover (2) further includes a boss (22) connected to the edge of the cover body (21), and the boss (22) is welded to the housing (1) to jointly seal the opening with the cover body (21); the boss (22) has opposite first top and first bottom, the cover body (21) has opposite second top and second bottom, the distance between the first top and the first bottom is greater than the distance between the second top and the second bottom, and a guiding portion is provided at the first bottom.

2. The battery box according to claim 1, wherein The guiding portion has a guiding surface (224) near the welding joint of the boss (22) and the housing (1), and the distance between the guiding surface (224) and the side wall of the housing (1) increases in the direction from the first top to the first bottom.

3. The battery box according to claim 1, wherein, A groove (225) is provided at the first top of the boss (22), and the groove (225) is near the welding surface (3) of the boss (22) and the housing (1).

4. The battery box according to any one of claims 1-3, wherein, The cover body (21) and the boss (22) are integrally formed, and the first top of the boss (22) is bent and connected to the edge of the top cover (2).

5. The battery box according to claim 4, wherein, The guiding portion has a guiding surface (224) near the welding joint of the boss (22) and the housing (1), and the included angle between the guiding surface (224) and the side wall of the housing (1) is 30 degrees - 60 degrees.

6. The battery box according to claim 3, wherein, The cover body (21) and the boss (22) are integrally formed, the boss (22) includes a bending portion (222) and relatively arranged first and second extending portions (221, 223), the first extending portion (221) is located between the second extending portion (223) and the cover body (21), the top of the first extending portion (221) is bent and connected to the edge of the cover body (21), the bottom of the first extending portion (221) is below the bottom of the cover body (21), the bending portion (222) is connected between the bottom of the first extending portion (221) and the bottom of the second extending portion (223), the top of the second extending portion (223) and the housing (1) and the top of the first extending portion (221) enclose the groove (225), and the guiding surface (224) is formed on the bending portion (222).

7. The battery box according to claim 3, wherein, The cover body (21) and the boss (22) are integrally formed. The boss (22) includes a bending portion (222) and a first extension portion (221) and a second extension portion (223) that are oppositely arranged. The top of the first extension portion (221) is bent and connected to the edge of the cover body (21). The bottom of the first extension portion (221) is located below the bottom of the cover body (21). The bending portion (222) is connected between the bottom of the first extension portion (221) and the bottom of the second extension portion (223). The top of the first extension portion (221), the top of the second extension portion (223), and the bending portion (222) enclose the groove (225). The guiding surface (224) is formed on the bending portion (222).

8. The battery box according to claim 6 or 7, wherein The distance between the groove (225) and the welding surface (3) is ≤ 2 mm.

9. The battery box according to claim 1, wherein, The boss (22) and the housing (1) have a welding surface (3). In the direction from the first top of the boss (22) to the first bottom of the boss (22), the length of the welding surface (3) is greater than the thickness of the top cover (2).

10. The battery box according to claim 9, wherein, In the direction from the first top of the boss (22) to the first bottom of the boss (22), the length of the welding surface (3) is 1 mm - 5 mm longer than the thickness of the cover body (21).

11. The battery box according to any one of claims 3-9, wherein, The distance between the groove (225) and the welding surface (3) is zero.

12. The battery box according to any one of claims 3-9, wherein, The bottom of the groove (225) is arc-shaped.

13. The battery box according to any one of claims 3-9, wherein, The shape of the groove (225) includes a triangle or a trapezoid.

14. The battery box according to any one of claims 2-9, wherein, The guiding surface (224) is arc-shaped.

15. The battery box according to any one of claims 6-9, wherein, The bending portion (222) is a U-shaped structure.

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