Battery shell and battery cell

Abstract

The utility model belongs to the technical field of batteries, and discloses a battery shell and a battery cell. The battery shell comprises a cover plate and a shell, the cover plate comprises a body and a lap joint convex part, and the lap joint convex part is convexly arranged at the top of the peripheral side of the body; a containing cavity is formed in the shell and provided with an opening, the cover plate blocks the opening, the lap joint protruding part abuts against the top of the shell, the body is suspended in the containing cavity, the lap joint protruding part is connected with the top of the shell in a welded mode, and the outer edge of the lap joint protruding part is inwards staggered by a preset distance H relative to the outer edge of the side wall of the shell. According to the battery shell and the battery cell provided by the utility model, the outward protruding height of the molten pool can be reduced, and the external dimension of the battery shell is ensured to be within a tolerance range.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a battery casing and a battery cell. Background Technology

[0002] The cover and casing of the battery are connected by welding. A molten pool is generated at the welding position. The molten metal forms a protrusion on the outside of the product. The protrusion protrudes from the surface of the battery casing, affecting the flatness of the welded surface and the overall size of the battery casing. In the subsequent assembly process, insufficient assembly clearance may occur, resulting in the battery cell not being able to be installed.

[0003] Therefore, there is an urgent need to design a battery casing and a battery cell to solve the above problems. Utility Model Content

[0004] One objective of this invention is to provide a battery casing that can reduce the outward protrusion height of the molten pool and ensure that the external dimensions of the battery casing are within tolerance.

[0005] Another objective of this invention is to provide a battery cell with a higher dimensional pass rate, which facilitates subsequent assembly.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] Battery casing, including:

[0008] The cover plate includes a body and an overlapping protrusion, wherein the overlapping protrusion protrudes from the top of the peripheral side of the body.

[0009] The housing has a cavity with an opening, a cover plate that blocks the opening, an overlapping protrusion that abuts against the top of the housing, a body that is suspended in the cavity, the overlapping protrusion that is welded to the top of the housing, and the outer edge of the overlapping protrusion that is offset inward by a predetermined distance H relative to the outer edge of the sidewall of the housing.

[0010] As an optional solution, 0.1mm≤H≤0.25mm.

[0011] As an alternative, the thickness of the aforementioned overlapping protrusion is defined as T1, and the total thickness of the aforementioned cover plate is defined as T2, where 0.4 ≤ T1 / T2 ≤ 0.6.

[0012] As an optional solution, 1.0mm≤T2≤3.0mm.

[0013] As an alternative, the thickness of the shell sidewall is defined as T3, where 0.25mm ≤ T3 ≤ 0.8mm.

[0014] As an optional solution, the aforementioned overlapping protrusion and the aforementioned housing are connected by side welding. The direction perpendicular to the height of the aforementioned battery housing is defined as the first direction. The first direction is the direction of the molten pool depth generated by the side welding. The molten pool includes connected trough areas and a straight section. The trough area is located below the straight section. In the aforementioned first direction, the bottom of the trough area is trough-shaped. The bottom of the straight section is gently set and extends to the top of the aforementioned cover plate. The cladding depth of the straight section is defined as L1, where L1 ≥ 0.6 mm.

[0015] As an alternative, the dimension of the aforementioned straight region in the aforementioned height direction is defined as L2, where L2≤L1.

[0016] As an alternative, in the first direction mentioned above, the depth of the deepest position of the trough region is defined as H1, where 1.0mm ≤ H1 ≤ 2.0mm.

[0017] As an alternative, the top height of the aforementioned flat area is either flush with or lower than the surface of the aforementioned cover plate.

[0018] As an alternative, the height of the protrusion of the molten pool on the outside of the battery casing is L4, where 0mm≤L4≤0.2mm.

[0019] The battery cell, including the aforementioned battery casing.

[0020] The beneficial effects of this utility model are as follows:

[0021] This utility model provides a battery casing. By offsetting the outer edge of the overlapping protrusion inward relative to the outer edge of the casing sidewall, during the welding process, a welding laser strikes the gap between the overlapping protrusion and the casing from the side, forming a cross-section as shown in the figure. Figure 2 The molten pool shown has a significantly reduced bulge compared to the non-staggered design, whether on the side of the battery casing or the top of the cover plate. This ensures that the external dimensions of the battery casing are within tolerance, guaranteeing the smooth progress of subsequent assembly.

[0022] This utility model also provides a battery cell, including the aforementioned battery casing. By using the aforementioned battery casing, the battery cell achieves a higher dimensional compliance rate, facilitating subsequent assembly. Attached Figure Description

[0023] Figure 1 This is a partial cross-sectional view of the battery casing before welding, provided in an embodiment of this utility model.

[0024] Figure 2 This is a partial cross-sectional view of the battery casing after welding, provided in an embodiment of this utility model.

[0025] In the picture:

[0026] 10. Cover plate; 11. Body; 12. Overlapping protrusion;

[0027] 20. Shell; 21. Receiving cavity;

[0028] 30. Molten pool; 31. Trough area; 32. Flat area. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0030] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" 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 or an electrical connection; 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. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0031] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0032] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, 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. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0033] This embodiment provides a battery casing that reduces the outward bulge height of the molten pool 30, ensuring that the external dimensions of the battery casing are within tolerance range. Figure 1As shown, the battery casing includes a cover plate 10 and a housing 20. The cover plate 10 includes a body 11 and an overlapping protrusion 12. The overlapping protrusion 12 protrudes from the top of the periphery of the body 11. A receiving cavity 21 is formed inside the housing 20, and it has an opening. The cover plate 10 blocks the opening, and the overlapping protrusion 12 abuts against the top of the housing 20. The body 11 is suspended in the receiving cavity 21. The overlapping protrusion 12 is connected to the top of the housing 20 by welding. The outer edge of the overlapping protrusion 12 is offset inward by a preset distance H relative to the outer edge of the side wall of the housing 20.

[0034] The battery casing is designed such that the outer edge of the overlapping protrusion 12 is offset inward from the outer edge of the side wall of the housing 20. During the welding process, the welding laser strikes the gap between the overlapping protrusion 12 and the housing 20 from the side, forming a cross-section as shown in the figure. Figure 2 The molten pool 30 shown has a significantly reduced protrusion compared to the non-staggered arrangement, whether on the side of the battery casing or on the top of the cover plate 10. This ensures that the external dimensions of the battery casing are within tolerance, guaranteeing the normal progress of subsequent assembly.

[0035] Optionally, 0.1mm ≤ H ≤ 0.25mm. When the offset distance exceeds 0.25mm, the contact area between the overlapping protrusion 12 and the housing 20 is insufficient, which will reduce the strength of the weld. When the offset distance is less than 0.1mm, the effect on reducing the protrusion of the molten pool 30 is not significant. For example, H = 0.1mm, 0.13mm, 0.15mm, 0.18mm, 0.2mm, 0.22mm, 0.25mm, etc.

[0036] Optionally, such as Figure 1 As shown, the thickness of the overlapping protrusion 12 is defined as T1, and the total thickness of the cover plate 10 is defined as T2, where 0.4 ≤ T1 / T2 ≤ 0.6. With this design, on the one hand, if this ratio is set too low, the overlapping protrusion 12, as part of the cover plate 10, is prone to bending and deformation at the connection point between the body 11 and the overlapping protrusion 12. On the other hand, if this ratio is set too high, it wastes raw materials, and during welding, the overlapping protrusion 12 is not easily penetrated, affecting the welding effect. For example, T1 / T2 = values ​​such as 0.4, 0.45, 0.5, 0.55, and 0.6.

[0037] Furthermore, 1.0mm ≤ T2 ≤ 3.0mm. For example, the thickness of the cover plate 10 is 1.0mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm, etc. If the thickness of the cover plate 10 is too thin, the structural strength is poor, making it difficult to support other structures on the cover plate 10, thereby reducing the bending strength of the cover plate 10, making it difficult to guarantee the flatness of the cover plate 10, and there is a possibility that during laser welding, there is less remaining material, and the laser penetrates into the battery, causing short circuits and other problems. If the thickness of the cover plate 10 is too thick, it will cause the battery to be too heavy. This design has a moderate thickness of the cover plate 10, which is lightweight and has good structural strength, is not easily deformed, and ensures flatness.

[0038] Optionally, such as Figure 1 As shown, the thickness of the sidewall of the housing 20 is defined as T3, where 0.25mm ≤ T3 ≤ 0.8mm. For example, the thickness of the housing 20 can be 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, etc. If the thickness of the housing 20 is too thin, the structural strength is poor, making it difficult to support the cover plate 10. Furthermore, during laser welding, there may be insufficient remaining material, allowing the laser to penetrate into the battery and cause short circuits. If the wall thickness of the housing 20 is too thick, the battery weight will be excessive. This design has a moderate thickness and good structural strength.

[0039] Optionally, such as Figure 1 and Figure 2 As shown, the overlapping protrusion 12 and the housing 20 are connected by side welding. The direction perpendicular to the height of the battery casing (Z direction in the figure) is defined as the first direction (X direction in the figure, which is perpendicular to the Z direction). The first direction is the direction of the molten pool 30 generated by the side welding. The molten pool 30 includes connected trough areas 31 and flat areas 32. The trough area 31 is located below the flat area 32. In the first direction, the bottom of the trough area 31 is trough-shaped, and the bottom of the flat area 32 is gently sloping and extends to the top of the cover plate 10. The cladding depth of the flat area 32 is defined as L1, where L1 ≥ 0.6 mm. It can be understood that during the side welding process, by adjusting the cladding depth of the flat area 32 corresponding to the welded molten pool 30 to be greater than 0.6 mm, it can be ensured that the volume of the molten material of the cover plate 10 and the housing 20 is sufficient to firmly weld the housing 20 and the cover plate 10 together.

[0040] Optionally, the cover plate 10 is made of a smooth aluminum sheet, which has good thermal conductivity and can quickly dissipate the heat inside the battery.

[0041] It should be noted that the shape of the molten pool 30 in the side weld is roughly as follows: Figure 2 As shown, the bottom of the flat area 32 is generally flat, transitioning smoothly to the top surface of the cover plate 10.

[0042] Optionally, such as Figure 2 As shown, the dimension of the straight zone 32 in the height direction is defined as L2, where L2 ≤ L1. It can be understood that during side welding, the depth of L1 should be sufficiently ensured to guarantee the melting depth of the straight zone 32. The larger L2 is, the more unmelted material is inside the molten pool 30. Therefore, L2 should be set smaller to ensure the melting effect inside the molten pool 30.

[0043] Optionally, in the first direction, the depth of the deepest position of the trough region 31 is defined as H1, where 1.0mm ≤ H1 ≤ 2.0mm. This setting ensures that the depth of the deepest position of the trough region 31 is within this range. In this case, the depth is approximately ten times H, ensuring sufficient melting of the material at the welding location. For example, the value of H1 can be 1.0mm, 1.2mm, 1.5mm, 1.7mm, 1.9mm, 2.0mm, etc.

[0044] Optionally, such as Figure 2 As shown, the top height of the flat area 32 is either flush with or below the surface of the cover plate 10. For ease of understanding, Figure 2 In this embodiment, the height of the flat area 32 protruding from the cover plate 10 is defined as L3. In the prior art, this value is positive. After the overlapping protrusion 12 and the outer edge of the housing 20 are offset by a distance H, the protrusion at this position disappears after a side welding test, ensuring the flatness and dimensional accuracy of the top of the cover plate 10. That is to say, in actual embodiment, the L3 indicated in the figure does not exist.

[0045] Optionally, such as Figure 2 As shown, the protrusion height of the molten pool 30 on the outside of the battery casing is L4, where 0mm ≤ L4 ≤ 0.2mm. In other words, after testing, the height of the molten pool 30 protruding from the side of the battery casing has also been reduced. In the prior art, the protrusion on this side is approximately 0.3mm. With the design of this embodiment, after side welding, a better effect can be achieved by preventing the formation of any protrusion, with most protrusions within 0.1mm and a small portion around 0.2mm, all within the tolerance range of the battery casing dimensions. For example, the values ​​of L4 are 0.05mm, 0.07mm, 0.1mm, 0.12mm, 0.15mm, 0.18mm, etc.

[0046] Optionally, such as Figure 2 As shown, the protrusion on the side of the molten pool 30 is located on the side of the molten pool 30 closer to the shell 20 than in the prior art, where the protrusion on the side of the molten pool 30 is located at the center of the molten pool 30. Essentially, this is due to the setting of H, causing the molten pool 30 to be oriented towards... Figure 2 The movement to the right side causes the lateral protrusions to deform, changing their height and position.

[0047] This embodiment also provides a battery cell, including the aforementioned battery casing. By using the aforementioned battery casing, the battery cell achieves a higher dimensional compliance rate, facilitating subsequent assembly.

[0048] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A battery housing, characterized by The battery shell comprises: a cover plate (10) comprising a body (11) and a lap protrusion (12) protruding from a top side of the body (11); a shell (20) having an accommodating cavity (21) formed therein and having an opening, wherein the cover plate (10) seals the opening, the lap protrusion (12) abuts against a top of the shell (20), the body (11) is suspended in the accommodating cavity (21), the lap protrusion (12) and the top of the shell (20) are connected by welding, and an outer edge of the lap protrusion (12) is arranged inwardly from an outer edge of a side wall of the shell (20) by a preset distance H.

2. The battery case of claim 1, wherein, 0.1mm≤H≤0.25mm.

3. The battery case of claim 1, wherein, A thickness of the lap protrusion (12) is defined as T1, a total thickness of the cover plate (10) is defined as T2, and 0.4≤T1 / T2≤0.

6.

4. The battery case of claim 3, wherein, 1.0mm≤T2≤3.0mm.

5. The battery case of claim 1, wherein, A thickness of the side wall of the shell (20) is defined as T3, and 0.25mm≤T3≤0.8mm.

6. The battery housing of any one of claims 1-5, wherein, The lap protrusion (12) and the shell (20) are connected by side welding, a first direction perpendicular to a height direction of the battery shell is defined as a penetration direction of a molten pool (30) generated by the side welding, the molten pool (30) comprises a connected valley region (31) and a flat region (32), the valley region (31) is located below the flat region (32), in the first direction, a bottom of the valley region (31) is in a valley shape, a bottom of the flat region (32) is arranged gently and extends to a top of the cover plate (10), a depth of the flat region (32) in the height direction is defined as L1, and L1≥0.6mm.

7. The battery case of claim 6, wherein, A size of the flat region (32) in the height direction is defined as L2, and L2≤L1.

8. The battery case of claim 6, wherein, In the first direction, a depth of a deepest position of the valley region (31) is defined as H1, and 1.0mm≤H1≤2.0mm.

9. The battery case of claim 6, wherein, A top of the flat region (32) is flush with or lower than a surface of the cover plate (10).

10. The battery case of claim 6, wherein, A protruding height of the molten pool (30) outside the battery shell is defined as L4, and 0mm≤L4≤0.2mm.

11. An electric cell, characterized by The battery shell comprises the battery shell according to any one of claims 1-10.

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