Battery case, battery cell and battery pack

Abstract

Disclosed in the present application are a battery case, a battery cell and a battery pack. The battery case comprises: a battery housing, which is provided with an opening; and a top cover body, which is arranged over the opening of the battery housing, wherein the end face of the battery housing facing the top cover body is arranged as an upper end face, which is provided with a first region and a second region arranged on the outer periphery of the first region; the top cover body is assembled onto the first region of the battery housing, and a welding gap is formed between the second region of the battery housing and a peripheral outer wall of the top cover body.

Description

A battery casing, a single battery cell, and a battery pack

[0001] This application claims priority to Chinese Patent Application No. 2024217736257, filed on July 24, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, and in particular to a battery casing, a single battery cell, and a battery pack. Background Technology

[0003] Depending on the battery size and structure, the welding of the top cover of a square aluminum battery can be divided into two processes: top cover vertical welding and top cover side welding. Technical issues

[0004] In actual top cover side welding, since multiple individual cells are assembled into modules, when the existing side welding protrusion of top cover side welding is relatively high, friction is easily generated between adjacent modules. Technical solutions

[0005] In a first aspect, this application provides a battery casing, comprising:

[0006] A battery casing, wherein the battery casing is provided with an opening;

[0007] The top cover body covers the opening of the battery housing; the end face of the battery housing facing the top cover body is designated as the upper end face and has a first region and a second region located circumferentially outside the first region.

[0008] The top cover body is assembled in a first region of the battery housing, and a welding notch is formed between the second region of the battery housing and the circumferential outer wall of the top cover body.

[0009] Secondly, this application provides a single battery cell, including the aforementioned battery casing, wherein the battery casing is a square casing.

[0010] Thirdly, this application provides a battery pack including the aforementioned single battery cell. Beneficial effects

[0011] The battery casing of this application solves the problem of high side weld protrusions and easy friction between modules in traditional side welding, and has the advantage of low weld protrusion; at the same time, it also solves the problem of low pressure resistance of large cell vertical welding products, and has the advantage of higher welding strength. Attached Figure Description

[0012] Figure 1 is a schematic diagram of the battery casing according to an embodiment of this application;

[0013] Figure 2 is a magnified view of part A in Figure 1;

[0014] Figure 3 is a front view structural schematic diagram of the battery casing according to an embodiment of this application;

[0015] Figure 4 is a magnified view of part B in Figure 3;

[0016] Figure 5 is a top view of the battery casing according to an embodiment of this application;

[0017] Figure 6 is a front view of the internal structure of the battery casing according to an embodiment of this application;

[0018] Attached figures: 1-Battery casing, 11-First region, 12-Second region, 2-Top cover body, 21-Assembly slot, 22-Circumferential outer wall, 3-Welding notch. Embodiments of the present invention

[0019] This application discloses a battery casing, as shown in Figures 1-6. The battery casing specifically includes a battery housing 1 with an opening. In the illustrated embodiment, the battery housing 1 has a cavity for assembling battery cells, and the cavity extends upward to the upper surface of the battery housing 1 to form an opening.

[0020] Specifically, the battery casing also includes a top cover body 2, which covers the opening of the battery casing 1; the end face of the battery casing 1 facing the top cover body 2 is designated as the upper end face, and a first region 11 and a second region 12 are provided on the upper end face in a circumferential direction outside the first region 11; the top cover body 2 is assembled in the first region 11 of the battery casing 1, and a welding notch 3 is formed between the second region 12 of the battery casing 1 and the circumferential outer wall 22 of the top cover body 2.

[0021] Given that existing top cover side-welding features relatively high side weld protrusions, which easily cause friction between adjacent modules, this battery casing addresses this issue by incorporating a welding notch 3 between the battery housing 1 and the top cover body 2. Therefore, during top cover side welding, the weld seam is contained within the welding notch 3, effectively increasing the contact distance between the welding protrusions of the modules and significantly resolving the friction problem between adjacent modules. Furthermore, the side welding process addresses the low voltage withstand strength issue of large-cell vertical welding products, resulting in higher weld strength.

[0022] In summary, this battery casing solves the problem of high side weld protrusions and easy friction between modules caused by traditional side welding, and has the advantage of low weld protrusion. At the same time, it also solves the problem of low voltage resistance of large cell vertical welding products, and has the advantage of higher welding strength.

[0023] It should be noted that the welding notch 3 can be specifically formed by the upper end face of the second region 12 of the battery casing 1 and the circumferential outer wall 22 of the top cover body 2, which will specifically form a stepped structure.

[0024] In actual welding, it was found that the existing side welding protrusions usually protrude 0.15mm or more from the outer side wall of the battery casing 1, which easily causes friction problems. To address this, multiple tests were conducted with welding protrusions of different sizes. It was found that controlling the size of the welding protrusion to within 0.1mm can solve the friction problem. Therefore, there are certain requirements for the width of the welding notch 3 itself.

[0025] In some embodiments, the width D1 of the welding notch 3 in the width direction of the battery casing ranges from 0.05mm ≤ D1 ≤ 0.15mm; and the width D2 of the welding notch 3 in the length direction of the battery casing ranges from 0.05mm ≤ D2 ≤ 0.15mm. The reason for selecting the widths D1 and D2 of the welding notch 3 within the range of 0.05mm-0.15mm is that the actual protruding size of the welding protrusion is usually 0.15mm or greater. For example, when the existing welding protrusion is 0.15mm, using the welding notch 3 structure of this application, even if the widths D1 and D2 of the welding notch 3 are set to the minimum value of 0.05mm, the welding protrusion can be controlled to 0.1mm, effectively solving the problem of friction. For example, when the existing weld protrusion is 0.25mm, such a weld protrusion size is rare. However, in order to have a greater tolerance, the widths D1 and D2 of the weld notch 3 can be set to the maximum value of 0.15mm, which can also control the weld protrusion to 0.1mm and effectively solve the problem of friction.

[0026] The width D1 of the welding notch 3 can be 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, or 0.15mm. In other embodiments, the width D1 of the welding notch 3 can also be other values ​​within the range of 0.05mm ≤ D1 ≤ 0.15mm.

[0027] The width D2 of the welding notch 3 can be 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, or 0.15mm. In other embodiments, the width D2 of the welding notch 3 can also be other values ​​within the range of 0.05mm ≤ D2 ≤ 0.15mm.

[0028] In some embodiments, the width D1 of the welding notch 3 ranges from 0.05mm to 0.1mm, and the width D2 of the welding notch 3 ranges from 0.05mm to 0.1mm. In actual welding, existing side welding protrusions are typically between 0.15mm and 0.2mm, so the widths D1 and D2 of the welding notch 3 can be controlled within the range of 0.05mm to 0.1mm. This arrangement provides sufficient space for the welding notch 3 to accommodate the weld protrusion while also ensuring the connection strength between the battery casing 1 and the top cover body 2.

[0029] In some embodiments, the width D1 of the welding notch 3 is 0.1 mm, and the width D2 of the welding notch 3 is 0.1 mm. This configuration creates a structure in which the surrounding areas of the welding notch 3 have equal dimensions, all of which are 0.1 mm in size. This structure is simple, easy to manufacture, and reduces manufacturing difficulty.

[0030] In some embodiments, the width of the welding notch 3 is D1 in the width direction of the battery casing and D2 in the length direction of the battery casing; wherein D1=D2. This arrangement can form a structure in which the surrounding areas of the welding notch 3 have equal dimensions, resulting in a simple structure that is easy to manufacture and reduces manufacturing difficulty.

[0031] In some embodiments, the height H1 between the top of the battery housing 1 and the top of the top cover body 2 in the height direction of the battery housing is in the range of 0.4mm ≤ H1 ≤ 0.8mm. This setting provides sufficient welding notch 3 to accommodate weld protrusions while ensuring the connection strength between the battery housing 1 and the top cover body 2.

[0032] The height H1 between the top of the battery casing 1 and the top of the top cover body 2 can be 0.5mm, 0.6mm, 0.7mm, or 0.8mm. In other embodiments, the height H1 between the top of the battery casing 1 and the top of the top cover body 2 can also be other values ​​within the range of 0.4mm ≤ H1 ≤ 0.8mm.

[0033] In some embodiments, the top cover body 2 has an assembly slot 21 on the side facing the battery housing 1, and the top cover body 2 is engaged with the opening of the battery housing 1 through the assembly slot 21. In the illustrated embodiment, the assembly slot 21 is provided on the bottom of the top cover body 2 facing the battery housing 1. This arrangement allows for a stable engagement structure through the assembly slot 21, ensuring that the top cover body 2 is stably fixed at the opening of the battery housing 1, thereby improving the overall structural stability.

[0034] The embodiments of this application also disclose a single battery cell, including the aforementioned battery casing. Therefore, it can be seen that this single battery cell can effectively avoid weld seam protrusion during side welding, thereby avoiding the problem of friction between adjacent modules, and has the advantage of low weld seam protrusion. Furthermore, the side welding process solves the problem of low voltage resistance in large-cell vertically welded products, and has the advantage of higher welding strength.

[0035] In some implementations, the battery casing is square to improve the structural stability of the square battery.

[0036] Embodiments of this application also disclose a battery pack, including the aforementioned single battery cell. Multiple cells can be combined to form a module, and this battery pack can include multiple modules. Therefore, this battery pack can effectively avoid weld seam protrusion during side welding, thereby avoiding the problem of easy friction between adjacent modules, and has the advantage of low weld seam protrusion. Furthermore, the welding process uses a side welding process, solving the problem of low withstand voltage strength in large-cell vertically welded products, and has the advantage of higher welding strength.

Claims

1. A battery case, comprising: a battery shell (1) provided with an opening; a top cover body (2) covering the opening of the battery shell (1); an end surface of the battery shell (1) towards the top cover body (2) is an upper end surface, and the upper end surface is provided with a first area (11) and a second area (12) outside the first area (11) in a circumferential direction; the top cover body (2) is assembled in the first area (11) of the battery shell (1), and a welding gap (3) is formed between the second area (12) of the battery shell (1) and a circumferential outer wall (22) of the top cover body (2).

2. A battery case according to claim 1, wherein, In the width direction of the battery case, the width D1 of the welding gap (3) ranges from 0.05 mm to 0.15 mm; In the length direction of the battery case, the width D2 of the welding gap (3) ranges from 0.05 mm to 0.15 mm.

3. A battery case according to claim 2, wherein, The width D1 of the welding gap (3) ranges from 0.05 mm to 0.1 mm, and the width D2 of the welding gap (3) ranges from 0.05 mm to 0.1 mm.

4. A battery case according to claim 3, wherein, The width D1 of the welding gap (3) is 0.1 mm, and the width D2 of the welding gap (3) is 0.1 mm.

5. The battery case of claim 1, wherein In the width direction of the battery case, the width of the welding gap (3) is D1; in the length direction of the battery case, the width of the welding gap (3) is D2; wherein D1=D2.

6. A battery case according to any one of claims 1-5, wherein, In the height direction of the battery case, the height H1 between the top of the battery shell (1) and the top of the top cover body (2) ranges from 0.4 mm to 0.8 mm.

7. A battery case according to claim 6, wherein, The height H1 between the top of the battery shell (1) and the top of the top cover body (2) is 0.6 mm.

8. A battery case according to any one of claims 1-5, wherein, The top cover body (2) is provided with an assembly notch (21) towards the bottom of the battery shell (1), and the top cover body (2) is clamped at the opening of the battery shell (1) through the assembly notch (21). 9.A single cell comprising the battery case according to any one of claims 1-8, wherein the battery case is a square case. 10.A battery pack comprising the single cell according to claim 9.

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