Square battery cover plate assembly

Abstract

The utility model belongs to the technical field of batteries, and particularly relates to a square battery cover plate assembly which comprises an aluminum shell and a cover plate, a plurality of clamping grooves are symmetrically distributed on the periphery of the aluminum shell, the clamping grooves are downwards concavely arranged on the periphery of the aluminum shell along the vertical direction, and a plurality of positioning blocks corresponding to the clamping grooves are arranged on the cover plate. The positioning blocks protrude out of the edge of the cover plate in the horizontal direction, and the positioning blocks are clamped in the clamping grooves. The positioning block is arranged on the cover plate and the clamping groove is formed in the aluminum shell, rapid positioning can be achieved through cooperation of the positioning block and the clamping groove, and the problem that due to the fact that the cover plate is directly pressed into the aluminum shell in a hard mode in a press-fitting station, a welding seam gap is poor or foreign matter is scraped and falls off is solved; meanwhile, the positioning block of the cover plate can be accurately positioned under the bearing of the clamping groove of the aluminum shell, so that the top cover is prevented from sinking or warping upwards in the aluminum shell to form a step; and therefore, the yield of the product is improved, and risks, such as explosion welding, insufficient welding and solder skips, which influence the quality and safety of the product are reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of batteries, and particularly relates to a square battery cover plate assembly. Background Art

[0002] Lithium-ion batteries are widely used in the fields of power, energy storage, and 3C digital. According to different packaging processes, lithium-ion batteries are divided into square batteries, soft-pack batteries, and cylindrical batteries. Among them, square batteries dominate the current power and energy storage markets. The packaging of square batteries adopts a laser welding process. Specifically, the battery core is placed inside an aluminum shell, the cover plate is tightly closed with the open end of the aluminum shell, and the gap of the closed cover is welded with a laser to weld the cover plate and the aluminum box into one body to isolate the outside air from entering the core and at the same time prevent the electrolyte inside the aluminum shell from leaking.

[0003] In the process of assembling the cover plate and the aluminum shell of the existing square battery, since the four sides of the cover plate are smooth side edges, and the inside of the open end of the aluminum shell is also a smooth plane or provided with slightly protruding steps. During the assembly process, the cover plate is pressed onto the open end of the aluminum shell by a pressing mechanism. Due to certain tolerances in the sizes of the cover plate and the aluminum shell, and the positioning of the battery and the limitation of the pressing mechanism will cause displacement or friction damage, resulting in large fluctuations in the gap between the cover plate and the aluminum shell; at the same time, the horizontal height of the large surface of the cover plate and the open end of the aluminum shell is inconsistent, and a step will be formed at the joint of the cover plate and the aluminum shell. During laser welding, problems such as explosion welding, false welding, leakage welding, and uneven weld seams will occur, which will cause liquid leakage and fire, affecting the quality and safety performance of the battery. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a battery cover plate assembly that is beneficial to the welding of a square aluminum shell in view of the deficiencies of the prior art, aiming to solve the problems of excessive gaps and inconsistent horizontal heights of the upper surface of the cover plate and the upper edge of the aluminum shell at the gap during the assembly process of the existing cover plate and the aluminum shell, resulting in problems such as explosion welding, false welding, leakage welding, and uneven weld seams during welding.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A square battery cover plate assembly includes an aluminum shell and a cover plate. A number of clamping grooves are symmetrically distributed around the aluminum shell. The clamping grooves are recessed vertically downward around the aluminum shell. The cover plate is provided with a number of positioning blocks corresponding to the clamping grooves. The positioning blocks protrude horizontally outward from the edge of the cover plate. The positioning blocks are clamped in the clamping grooves. The width of the positioning blocks is equal to the width of the clamping grooves. The clamping grooves can be symmetrically designed or evenly distributed around the upper edge of the aluminum shell. The corresponding positioning blocks are distributed correspondingly so that the positioning blocks can be embedded in the clamping grooves, enabling the cover plate to be flatly buckled in the upper-edge opening of the aluminum shell, achieving precise positioning and quickly forming a sealed square battery housing, reducing friction damage or displacement between the cover plate and the aluminum shell during the pressing process. Both the clamping grooves and the positioning blocks are rectangular and have the same width, forming a firm battery housing after being embedded and buckled.

[0007] Preferably, the protruding length of the positioning block is L, satisfying the following relationship: 0 < L ≤ 3 mm. Specifically, the protruding length L of the positioning block is 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, 2.5 mm, 3 mm, etc., which is convenient for embedding into the clamping grooves and can be adjusted accordingly according to the specific size of the clamping grooves.

[0008] Preferably, the protruding length of the positioning block is the same as the wall thickness of the aluminum shell. When the positioning block is embedded in the clamping groove, the side surface of the positioning block and the outer side wall of the aluminum shell are in the same vertical plane, forming a flat surface, making the overall square battery housing relatively smooth and flat.

[0009] Preferably, the recessed depth of the clamping groove is H, satisfying the following relationship: 0 < H ≤ 10 mm. Specifically, the recessed depth H of the clamping groove is 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, etc., which is convenient for receiving the positioning blocks and can be adjusted accordingly according to the specific size of the positioning blocks.

[0010] Preferably, the recessed depth of the clamping groove is the same as the thickness of the positioning block. When the clamping groove receives the positioning block, the upper surfaces of the positioning block and the cover plate are in the same horizontal plane as the upper edge of the aluminum shell, forming a flat surface, making the overall square battery housing relatively smooth and flat. Preventing the formation of a step between the two can make the subsequent laser welding process smoother, so as to form a battery housing with better sealing performance as a whole.

[0011] Preferably, a slope is provided at the connection between the aluminum shell and the clamping groove, and a bevel is provided at the connection between the cover plate and the positioning block. The slope fits closely with the bevel. The inclination angle of the slope is the same as that of the bevel. When the cover plate is buckled onto the aluminum shell, the slope and the bevel are in close contact to achieve a sealing and protection effect.

[0012] Preferably, the thickness T of the upper edge of the aluminum shell is less than the protruding length L of the positioning block, and the following relationship is satisfied: L - T ≤ 1 mm. Since the slope is obtained by thinning the inner wall of the upper edge of the aluminum shell to accommodate the bevel on the cover plate, the thickness T of the upper edge of the aluminum shell is less than the protruding length L of the positioning block. The slight gap between the two can serve as a cavity for molten aluminum during the laser welding process, avoiding unevenness on the surface of the cover plate caused by laser welding and making the welding sealing effect better.

[0013] Preferably, a positive terminal and a negative terminal penetrate through the upper surface of the cover plate, and a liquid injection hole and an explosion-proof valve mounting hole are also provided. A stop frame is provided on the lower surface of the cover plate. One first fixing boss is provided on each side of the stop frame in the length direction of the cover plate, and the first fixing boss is opposite to the positioning block. The cover plate is limited to the inner side wall of the aluminum shell by the first fixing boss on the stop frame, and at the same time, the position of the battery cell in the aluminum shell can be limited.

[0014] Preferably, several second fixing bosses are further provided in the middle of the stop frame. The position of the battery cell is further limited by the second fixing bosses, making its installation more secure.

[0015] Preferably, a chamfer is provided on the vertical side of the aluminum shell, and a recess corresponding to the chamfer is provided on the first fixing boss. By providing the chamfer on the vertical side of the aluminum shell, on the one hand, the R angle of the battery cell in the aluminum shell can be limited, improving the battery energy density, and on the other hand, the overall battery shell is made more rounded and convenient to grasp. At the same time, a recess is provided for the first fixing boss embedded in the aluminum shell for corresponding treatment, and the four corners of the cover plate are also cut.

[0016] Compared with the prior art, the beneficial effects of the present utility model are as follows: A square battery cover plate assembly provided by the present utility model aims to nest the positioning blocks protruding from the periphery of the cover plate into the corresponding clamping grooves around the upper edge of the aluminum shell by arranging positioning blocks around the cover plate and clamping grooves around the upper edge of the aluminum shell, which can achieve rapid positioning and avoid problems such as poor weld gaps or scratching and dropping foreign objects caused by directly pressing the cover plate hard into the aluminum shell at the pressing station; at the same time, the positioning blocks of the cover plate can be accurately positioned under the bearing of the clamping grooves of the aluminum shell, avoiding unevenness between the upper surface of the cover plate and the upper edge of the aluminum shell, so that the top cover is sunken or warped in the aluminum shell to form a step; thereby improving the yield of the product and reducing risks such as explosion welding, false welding, and leakage welding that affect the product quality and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a three-dimensional structural schematic diagram of an embodiment of the present utility model.

[0018] Figure 2 is a three-dimensional structural exploded view of an embodiment of the present utility model.

[0019] Figure 3 is a front-direction structural schematic diagram of an embodiment of the present utility model.

[0020] Figure 4 is a front-direction structural exploded view of an embodiment of the present utility model.

[0021] Figure 5 is a side-direction structural schematic diagram of an embodiment of the present utility model.

[0022] Figure 6 is a side-direction structural exploded view of an embodiment of the present utility model.

[0023] Figure 7 is a top-direction structural schematic diagram of an embodiment of the present utility model.

[0024] Figure 8 is Figure 1 a partial enlarged schematic diagram at A of

[0025] Figure 9 is Figure 2 a partial enlarged schematic diagram at B of

[0026] Figure 10 is Figure 4 a partial enlarged schematic diagram at C of

[0027] REFERENCE MARKS:

[0028] 1. Aluminum shell, 11. Clamping groove, 12. Inclined surface, 13. Chamfer;

[0029] 2. Cover plate, 21. Positioning block, 22. Inclined platform, 23. Positive terminal, 24. Negative terminal, 25. Liquid injection hole, 26. Explosion-proof valve mounting hole, 27. Stopping frame, 28. First fixing boss, 281. Concave portion, 29. Second fixing boss. Detailed implementation manners

[0030] Next, the technical solutions in the embodiments of the present invention will be described clearly and completely. Apparently, the described embodiments are only a part rather than all of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0031] As Figures 1-7 shown, a square battery cover plate assembly includes an aluminum shell 1 and a cover plate 2. A plurality of clamping grooves 11 are symmetrically distributed around the aluminum shell 1. The clamping grooves 11 are recessed downward in the vertical direction around the aluminum shell 1. A plurality of positioning blocks 21 corresponding to the clamping grooves 11 are provided on the cover plate 2. The positioning blocks 21 protrude outward from the edge of the cover plate 2 in the horizontal direction. The positioning blocks 21 are clamped in the clamping grooves 11. The width of the positioning block 21 is equal to the width of the clamping groove 11. The clamping grooves 11 can be symmetrically designed or evenly distributed around the upper edge of the aluminum shell 1, and the corresponding positioning blocks 21 corresponding to the clamping grooves 11 are designed correspondingly, so as to inlay the positioning blocks 21 in the clamping grooves 11, so that the cover plate 2 is flatly buckled in the upper open of the aluminum shell 1, so as to achieve precise positioning and quickly form a sealed square battery housing, reducing the friction damage or displacement of the cover plate 2 and the aluminum shell 1 during the pressing process. Both the clamping grooves 11 and the positioning blocks 21 are rectangular, and their widths are the same. After being inlaid and buckled, a firm battery housing is formed. In this embodiment, one clamping groove 11 is provided on each side in the width direction of the aluminum shell 1, and the two clamping grooves 11 are symmetrically arranged. Similarly, one positioning block 21 corresponding to the position of the clamping groove 11 is provided on each side in the width direction of the cover plate 2. The clamping groove 11 and the positioning block 21 have the same width, which is convenient for forming a sealed battery outer shell after buckling.

[0032] Furthermore, as Figure 8 and Figure 10 shown, the protruding length of the positioning block 21 is L, satisfying the following relationship: 0 < L ≤ 3 mm. Specifically, the protruding length L of the positioning block 21 is 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, 2.5 mm, 3 mm, etc., which is convenient for embedding into the clamping groove 11 and can be adjusted accordingly according to the specific size of the clamping groove 11. In this embodiment, the protruding length L of the positioning block 21 is 3 mm.

[0033] Further, the protruding length of the positioning block 21 is the same as the wall thickness of the aluminum shell 1. When the positioning block 21 is embedded into the clamping groove 11, the side surface of the positioning block 21 and the outer side wall of the aluminum shell 1 are in the same vertical plane, forming a flat surface, making the overall square battery shell relatively smooth and flat.

[0034] Further, as Figure 6 and Figure 8 shown, the recessed depth of the clamping groove 11 is H, satisfying the following relational expression: 0 < H ≤ 10 mm. Specifically, the recessed depth H of the clamping groove 11 is 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, etc., which is convenient for receiving the positioning block 21 and can be adjusted accordingly according to the specific size of the positioning block 21. In this embodiment, the recessed depth H of the clamping groove 11 is 8 mm.

[0035] Further, the recessed depth of the clamping groove 11 is the same as the thickness of the positioning block 21. When the clamping groove 11 receives the positioning block 21, the upper surfaces of the positioning block 21 and the cover plate 2 are in the same horizontal plane as the upper edge of the aluminum shell 1, forming a flat surface, making the overall square battery shell relatively smooth and flat. Eliminating the formation of a step between the two can make the subsequent laser welding process smoother, so as to form an overall battery shell with better airtight performance.

[0036] Further, as Figure 9 and Figure 10 shown, a bevel 12 is provided at the connection between the aluminum shell 1 and the clamping groove 11, and a bevel platform 22 is provided at the connection between the cover plate 2 and the positioning block 21, and the bevel 12 is in contact with the bevel platform 22. The inclination angle of the bevel 12 is the same as the inclination angle of the bevel platform 22. When the cover plate 2 is buckled onto the aluminum shell 1, the bevel 12 and the bevel platform 22 are in close contact to achieve a sealing and protecting effect.

[0037] Further, as Figure 8 shown, the thickness T of the upper edge of the aluminum shell 1 is less than the protruding length L of the positioning block 21, and satisfies the following relational expression: L - T ≤ 1 mm. Since the bevel 12 is obtained by thinning the inner wall of the upper edge of the aluminum shell 1 to accommodate the bevel platform 22 on the cover plate 2, the thickness T of the upper edge of the aluminum shell 1 is less than the protruding length L of the positioning block 21. The slight gap between the two can serve as a cavity for accommodating the molten aluminum during the laser welding process, avoiding unevenness on the surface of the cover plate 2 caused by laser welding, and at the same time making the welding sealing effect better. In this embodiment, the thickness T of the upper edge of the aluminum shell 1 is 2.5 mm, and there is a 0.5 mm gap between the aluminum shell 1 and the cover plate 2.

[0038] Further, as Figure 2 and Figure 7As shown in the figure, a positive terminal 23 and a negative terminal 24 penetrate through the upper surface of the cover plate 2. There are also a liquid injection hole 25 and an explosion-proof valve mounting hole 26. A stop frame 27 is provided on the lower surface of the cover plate 2. On both sides of the cover plate 2 in the length direction, there is a first fixing boss 28 on the stop frame 27. The first fixing boss 28 faces the positioning block 21. The cover plate 2 is limited to the inner side wall of the aluminum shell 1 by the first fixing boss 28 on the stop frame 27, and at the same time, the position of the battery cell in the aluminum shell 1 can be limited.

[0039] Furthermore, several second fixing bosses 29 are also provided in the middle of the stop frame 27. The position of the battery cell is further limited by the second fixing bosses 29, making its installation more firm.

[0040] Furthermore, as Figure 1 and Figure 2 shown in the figure, a chamfer 13 is provided on the vertical edge of the aluminum shell 1, and a recess 281 corresponding to the chamfer 13 is provided on the first fixing boss 28. By providing the chamfer 13 on the vertical edge of the aluminum shell 1, on the one hand, the R angle of the battery cell in the aluminum shell 1 can be limited, improving the battery energy density. On the other hand, the overall shape of the battery shell is more rounded and convenient to grasp. At the same time, a recess 281 is provided for corresponding treatment of the first fixing boss 28 embedded in the aluminum shell 1, and the four corners of the cover plate 2 are also cut.

[0041] According to the disclosure and teachings of the above specification, those skilled in the art of the present utility model can also make changes and modifications to the above embodiments. Therefore, the present utility model is not limited to the above specific embodiments. Any obvious improvements, substitutions or variations made by those skilled in the art on the basis of the present utility model all fall within the protection scope of the present utility model. In addition, although some specific terms are used in this specification, these terms are only for convenience of description and do not constitute any limitation to the present utility model.

Claims

1. A square battery cover plate assembly, characterized in that: It includes an aluminum shell (1) and a cover plate (2). A number of clamping grooves (11) are provided around the aluminum shell (1). The clamping grooves (11) are recessed downward in the vertical direction around the aluminum shell (1). A number of positioning blocks (21) corresponding to the clamping grooves (11) are provided on the cover plate (2). The positioning blocks (21) protrude outward from the edge of the cover plate (2) in the horizontal direction. The positioning blocks (21) are clamped in the clamping grooves (11).

2. The square battery cover plate assembly according to claim 1, characterized in that: The protruding length of the positioning block (21) is L, satisfying the following relationship: 0 < L ≤ 3 mm.

3. The square battery cover plate assembly according to claim 2, wherein: The protruding length of the positioning block (21) is the same as the wall thickness of the aluminum shell (1).

4. The square battery cover plate assembly according to claim 1, wherein: The recessed depth of the clamping groove (11) is H, satisfying the following relationship: 0 < H ≤ 10 mm.

5. The square battery cover plate assembly according to claim 4, wherein: The recessed depth of the clamping groove (11) is the same as the thickness of the positioning block (21).

6. The square battery cover plate assembly according to claim 2, characterized in that: A bevel surface (12) is provided at the connection of the aluminum shell (1) and the clamping groove (11), and a bevel platform (22) is provided at the connection of the cover plate (2) and the positioning block (21). The bevel surface (12) is in fit with the bevel platform (22).

7. The square battery cover plate assembly according to claim 6, wherein: The thickness T of the upper edge of the aluminum shell (1) is less than the protruding length L of the positioning block (21), and satisfies the following relationship: L - T ≤ 1 mm.

8. The square battery cover plate assembly according to claim 1, wherein: A positive terminal (23) and a negative terminal (24) are penetrated through the upper surface of the cover plate (2). A liquid injection hole (25) and an explosion-proof valve mounting hole (26) are also provided. A stop frame (27) is provided on the lower surface of the cover plate (2). A first fixing boss (28) is provided on each side of the stop frame (27) in the length direction of the cover plate (2). The first fixing boss (28) is opposite to the positioning block (21).

9. The square battery cover plate assembly according to claim 8, wherein: A number of second fixing bosses (29) are also provided in the middle of the stop frame (27).

10. The square battery cover plate assembly according to claim 8, wherein: A chamfer (13) is provided on the vertical edge of the aluminum shell (1), and a recessed portion (281) corresponding to the chamfer (13) is provided on the first fixing boss (28).

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