Battery cell and battery pack
By incorporating a connecting piece structure with clearance openings in the battery cell, the problem of warping after welding the connecting piece is solved, achieving high-quality assembly and safety performance of the battery cell.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SUNWODA MOBILITY ENERGY TECHNOLOGY CO LTD
- Filing Date
- 2025-05-15
- Publication Date
- 2026-05-08
AI Technical Summary
In power batteries, warping can easily occur after the connecting pieces and tabs are welded together, affecting the assembly and performance of the battery.
A battery cell structure is designed in which the welding part of the connecting piece is provided with an avoidance opening and is set in accordance with the liquid injection hole. The connecting part is connected to the edge of the welding part to enhance the structural strength at the avoidance opening and reduce the possibility of deformation of the welding part.
By avoiding the opening design, interference of the connecting piece with the electrolyte injection is avoided, the structural strength of the welded part is improved, the possibility of deformation of the welded part is reduced, and the assembly quality and safety performance of the battery cell are improved.
Smart Images
Figure CN224217670U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of power battery technology, and more specifically, to a battery cell and a battery pack. Background Technology
[0002] In the manufacturing process of power batteries, it is usually necessary to weld connecting pieces to the terminals and tabs respectively. The connecting pieces are used to achieve electrical connection between the terminals and tabs. In traditional power batteries, in order to avoid the connecting pieces blocking the electrolyte filling hole, it is usually necessary to open an avoidance opening at the end where the connecting piece is connected to the tab. However, after the connecting piece is welded to the tab, the opening of the connecting piece usually warps, which affects the assembly and performance of the battery. Utility Model Content
[0003] In view of this, the purpose of this application is to overcome the shortcomings of the prior art and provide a battery cell that can reduce the probability of deformation after the connecting pieces are welded.
[0004] This application also provides a battery pack.
[0005] To achieve the above objectives, the technical solution adopted in this application is as follows:
[0006] In a first aspect, this application provides a battery cell, including a housing, a top cover assembly, an electrode assembly, and a connecting piece;
[0007] The housing has a receiving cavity;
[0008] The top cover assembly includes a top cover and an electrode post disposed on the top cover. The top cover is connected to the housing and seals the receiving cavity. The top cover is provided with a liquid injection hole, which is spaced apart from the electrode post.
[0009] The electrode assembly is located in the receiving cavity, and the electrode assembly has an electrode tab on the side facing the top cover;
[0010] The connecting piece is located in the receiving cavity. The connecting piece is provided with a connecting welding part and a connecting part. The welding part has a clearance opening at one end facing the connecting part. The connecting part is at least partially connected to the edge of the welding part located at the clearance opening. The welding part is welded to the electrode post or the electrode tab. The clearance opening is arranged opposite to the liquid injection hole.
[0011] In an optional embodiment, the welding part and the connecting part are integrally formed.
[0012] In an optional embodiment, the battery cell has a thickness direction, the liquid injection hole and the clearance opening are arranged opposite to each other in the thickness direction, the welded part has a dimension of L1 mm in the thickness direction, and the connecting part has a dimension of L2 mm in the thickness direction, satisfying: L1≤L2.
[0013] In an optional embodiment, the welded portion engages with the connecting portion.
[0014] In an optional embodiment, the connecting piece is further provided with a snap-fit portion, which is located at the end of the welding portion facing the connecting portion and is spaced apart from the clearance opening. The connecting portion has a snap-fit hole, and the snap-fit portion passes through the snap-fit hole to engage and connect the welding portion and the connecting portion.
[0015] In an optional embodiment, the welded portion is bonded or welded to the connecting portion.
[0016] In an optional embodiment, the battery cell has intersecting thickness and length directions, the injection hole and the clearance opening are arranged opposite to each other in the thickness direction, and the clearance opening is located at one end of the welding part along the length direction. The end of the welding part along the length direction near the clearance opening is bonded or welded to one end of the connecting part along the length direction.
[0017] In an optional embodiment, the connecting piece is further provided with an overlapping portion, which is located at one end of the connecting portion facing the welding portion along the length direction. The welding portion is provided with an overlapping groove on its surface along the thickness direction. The overlapping portion is embedded in the overlapping groove and is bonded or welded to the groove wall of the overlapping groove.
[0018] In an optional embodiment, in the thickness direction, the orthographic projection shape of the lap joint onto the welded portion is polygonal or arc-shaped.
[0019] Secondly, this application provides a battery pack, including: a battery cell as described in any of the foregoing embodiments.
[0020] The battery cell of this application has the following advantages:
[0021] In the battery cell of this application, the welding portion of the connecting piece is used to weld to the terminal post or the tab. In this way, the electrical connection between the terminal post and the tab can be achieved through the connecting piece. Since the welding portion has a clearance opening that is arranged opposite to the injection hole, when the electrolyte is injected into the receiving cavity through the injection hole, the clearance opening can avoid the injection of electrolyte, thus preventing the connecting piece from interfering with the injection of electrolyte. Furthermore, since the connecting portion is at least partially connected to the edge of the welding portion located at the clearance opening, the edge of the welding portion located at the clearance opening can be closed through the connecting portion. When welding the connecting piece and the tab, the structural strength of the edge of the welding portion located at the clearance opening can be increased, thereby reducing the possibility of deformation of the edge of the welding portion located at the clearance opening during welding, reducing the possibility of interference between the connecting piece and the tab, and reducing the impact on the assembly of the battery cell. Attached Figure Description
[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0023] Figure 1 A schematic diagram of the exploded structure of a single battery cell in this application is shown;
[0024] Figure 2 A three-dimensional structural schematic diagram of the connecting piece of Embodiment 1 of this application is shown;
[0025] Figure 3 This shows a schematic diagram of the main structure of the connecting piece in Embodiment 1 of this application;
[0026] Figure 4 A three-dimensional structural schematic diagram of the connecting piece of Embodiment 2 of this application is shown;
[0027] Figure 5 This shows a schematic diagram of the main structure of the connecting piece in Embodiment 2 of this application;
[0028] Figure 6 This shows a top view of the connecting piece in Embodiment 3 of this application;
[0029] Figure 7 An exploded view of the connecting piece of Embodiment 3 of this application is shown;
[0030] Figure 8 A top view of the connecting piece in Embodiment 4 of this application is shown;
[0031] Figure 9A top view of the connecting piece in Embodiment 5 of this application is shown;
[0032] Figure 10 An exploded view of the connecting piece in Embodiment 5 of this application is shown;
[0033] Figure 11 This shows a top view of the connecting piece in Embodiment 6 of this application;
[0034] Figure 12 An exploded structural diagram of the connecting piece of Embodiment 6 of this application is shown.
[0035] Explanation of key component symbols:
[0036] 100 - Housing;
[0037] 200 - Top cap assembly; 210 - Top cap; 211 - Injection port; 220 - End post;
[0038] 300 - Electrode assembly; 310 - Tab; 320 - Electrode body;
[0039] 400-Connecting piece; 410-Welding part; 411-Avoidance opening; 412-Overlap groove; 413-First welding area; 414-Second welding area; 420-Connecting part; 421-Snap-fit hole; 430-Snap-fit part; 440-Overlap part;
[0040] x - thickness direction; y - length direction. Detailed Implementation
[0041] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals 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 application, and should not be construed as limiting this application.
[0042] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application.
[0043] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.
[0044] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," 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 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 application according to the specific circumstances.
[0045] In this application, unless otherwise expressly 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.
[0046] Reference Figure 1 As shown, the battery cell involved in the embodiments of this application includes: a housing 100, a top cover assembly 200, an electrode assembly 300, and a connecting piece 400.
[0047] Specifically, the housing 100 has a receiving cavity; the top cover assembly 200 includes a top cover 210 and an electrode post 220 disposed on the top cover 210, the top cover 210 is connected to the housing 100 and seals the receiving cavity; the top cover 210 is provided with a liquid injection hole 211, the liquid injection hole 211 and the electrode post 220 are spaced apart; the electrode assembly 300 is located in the receiving cavity, and the electrode assembly 300 is provided with an electrode tab 310 on the side facing the top cover 210; the connecting piece 400 is located in the receiving cavity, the connecting piece 400 is provided with a connecting welding part 410 and a connecting part 420, the welding part 410 is provided with a clearance opening 411 at one end facing the connecting part 420, the connecting part 420 is at least partially connected to the edge of the welding part 410 located at the clearance opening 411, the welding part 410 is welded to the electrode post 220 or the electrode tab 310, and the clearance opening 411 is disposed opposite to the liquid injection hole 211.
[0048] In the battery cell of this application, the welding portion 410 of the connecting piece 400 is used to weld with the terminal 220 and the tab 310. Thus, an electrical connection between the terminal 220 and the tab 310 can be achieved through the connecting piece 400. Since the welding portion 410 has a clearance opening 411 opposite to the injection hole 211, when electrolyte is injected into the receiving cavity through the injection hole 211, the clearance opening 411 can prevent interference with the electrolyte injection by the connecting piece 400. Furthermore, since the connecting portion 410... The edge of the connecting piece 400 located at the clearance opening 411 is connected to the welding part 410. In this way, the edge of the welding part 410 located at the clearance opening 411 can be closed by the connecting part 420. When welding the connecting piece 400 and the tab 310, the structural strength of the edge of the welding part 410 located at the clearance opening 411 can be increased, thereby reducing the possibility of deformation of the edge of the welding part 410 located at the clearance opening 411 during welding, reducing the possibility of interference between the connecting piece 400 and the tab 310, and reducing the impact on the assembly of the battery cell.
[0049] Example 1
[0050] Reference Figure 2 as well as Figure 3 As shown, in Embodiment 1, the battery cell has a thickness direction x, the welding part 410 and the connecting part 420 are integrally formed, the liquid injection hole 211 and the clearance opening 411 are arranged opposite to each other in the thickness direction x, the dimension of the welding part 410 in the thickness direction x is L1 mm, and the dimension of the connecting part 420 in the thickness direction x is L2 mm, satisfying: L1=L2.
[0051] It should be noted that the thickness direction x is Figure 1 The direction indicated by x in the middle.
[0052] In this embodiment, since the welding part 410 and the connecting part 420 are integrally formed, the structural strength of the connection between the welding part 410 and the connecting part 420 can be improved, thereby improving the structural strength of the connecting piece 400 and enhancing its resistance to deformation. At the same time, in the thickness direction x, since the dimensions L1 mm of the welding part 410 and L2 mm of the connecting part 420 satisfy L1 = L2, the structural strength of the connection between the welding part 410 and the connecting part 420 can be improved, and the connecting part 420 can be prevented from protruding from the welding part 410 in the thickness direction x, thus preventing the connecting piece 400 from occupying too much cavity space, thereby improving the energy density of the battery cell.
[0053] Example 2
[0054] Reference Figure 4 as well as Figure 5As shown, in Embodiment 2, the welding part 410 and the connecting part 420 are integrally formed structures. The dimension of the welding part 410 in the thickness direction x is L1 mm, and the dimension of the connecting part 420 in the thickness direction x is L2 mm, satisfying: L1 < L2.
[0055] In this embodiment, since the welding part 410 and the connecting part 420 are integrally formed, the structural strength of the connection between the welding part 410 and the connecting part 420 can be improved, thereby improving the structural strength of the connecting piece 400 and enhancing its resistance to deformation. Furthermore, in the thickness direction x, since the dimensions L1 mm of the welding part 410 and L2 mm of the connecting part 420 satisfy L1 < L2, the structural strength of the connection between the welding part 410 and the connecting part 420 can be improved, while reducing the material consumption in manufacturing the connecting piece 400, thus lowering its manufacturing cost. Additionally, the weight of the connecting piece 400 can be reduced, preventing it from becoming too heavy and compressing the top cover assembly 200 and / or the electrode assembly 300, thus reducing the possibility of damage to the top cover assembly 200 and / or the electrode assembly 300 by the connecting piece 400.
[0056] Example 3
[0057] Reference Figure 6 as well as Figure 7 As shown, in Embodiment 3, the welding part 410 and the connecting part 420 are engaged and connected.
[0058] In this embodiment, since the welding part 410 and the connecting part 420 are engaged, the connection between the welding part 410 and the connecting part 420 can be improved, the production efficiency of the connecting piece 400 can be improved, and further, the connecting part 420 can be easily replaced and maintained, so that the connecting part 420 can be made of a different material than the welding part 410. That is, the connecting part 420 can be made of a material with good deformation resistance and low price, thereby improving the deformation resistance of the connecting piece 400 and reducing the manufacturing cost of the connecting piece 400. Preferably, the connecting part 420 is made of metal to improve the high temperature resistance of the connecting part 420 and prevent the connecting part 420 from being melted by the high temperature of welding during the welding process with the tab 310 or the post 220.
[0059] Continue to refer to Figure 6 as well as Figure 7 As shown, in embodiment 3, the connecting piece 400 is further provided with a snap-fit portion 430. The snap-fit portion 430 protrudes from the end of the welding portion 410 facing the connecting portion 420 and is spaced apart from the clearance opening 411. The connecting portion 420 is provided with a snap-fit hole 421, and the snap-fit portion 430 passes through the snap-fit hole 421 to snap-fit and connect the welding portion 410 and the connecting portion 420.
[0060] In this embodiment, when it is necessary to connect the connecting part 420 and the welding part 410, it is only necessary to make the snap-fit part 430 on the welding part 410 pass through the snap-fit hole 421 on the connecting part 420, so that the connection between the welding part 410 and the connecting part 420 can be achieved through the snap-fit connection between the snap-fit part 430 and the snap-fit hole 421, and the connection stability between the welding part 410 and the connecting part 420 can be improved.
[0061] Specifically, in this embodiment, the snap-fit portion 430 may also protrude from the end of the connecting portion 420 facing the welding portion 410, and the snap-fit hole 421 is opened on the welding portion 410. The snap-fit portion 430 passes through the snap-fit hole 421 to realize the snap-fit connection between the welding portion 410 and the connecting portion 420.
[0062] Example 4
[0063] Reference Figure 8 As shown, in Embodiment 4, the welding part 410 is bonded or welded to the connecting part 420.
[0064] In this embodiment, since the welding part 410 and the connecting part 420 are bonded or welded together, the bonding or welding connection improves the connection stability between the welding part 410 and the connecting part 420 compared to the snap-fit connection, so that the welding part 410 and the connecting part 420 can be connected more firmly.
[0065] Continue to refer to Figure 8 As shown, in embodiment 4, the battery cell also has a length direction y, the liquid injection hole 211 and the clearance opening 411 are arranged opposite to each other in the thickness direction x, and the clearance opening 411 is located at one end of the welding part 410 along the length direction y. The end of the welding part 410 along the length direction y close to the clearance opening 411 is bonded or welded to one end of the connecting part 420 along the length direction y.
[0066] It should be noted that the length direction y is Figure 1 The direction indicated by y in the middle.
[0067] In this embodiment, since the end of the welding part 410 along the length direction y near the clearance opening 411 is bonded or welded to the end of the connecting part 420 along the length direction y, the end face of the welding part 410 along the length direction y and the end face of the connecting part 420 along the length direction y can be bonded or welded, thereby realizing the connection between the welding part 410 and the connecting part 420. At the same time, the connecting part 420 can be connected to the end of the welding part 410 along the length direction y near the clearance opening, thereby increasing the structural strength of the edge of the welding part 410 at the clearance opening 411, thereby reducing the possibility of deformation of the edge of the welding part 410 at the clearance opening 411 during welding.
[0068] Example 5
[0069] Reference Figure 9 as well as Figure 10 As shown, the connecting piece 400 is also provided with an overlapping portion 440. The overlapping portion 440 protrudes along the length direction y at one end of the connecting portion 420 facing the welding portion 410. The welding portion 410 has an overlapping groove 412 on its surface along the thickness direction x. The overlapping portion 440 is embedded in the overlapping groove 412 and is bonded or welded to the groove wall of the overlapping groove 412. In the thickness direction x, the orthographic projection shape of the overlapping portion 440 on the welding portion 410 is a polygonal structure.
[0070] Specifically, in this embodiment, the overlap groove 412 is provided at one end of the welded part 410 along the length direction y near the avoidance opening 411.
[0071] Specifically, in this embodiment, the orthographic projection shape of the overlapping portion 440 on the welding portion 410 is a rectangular structure. In other embodiments, the orthographic projection shape of the overlapping portion 440 on the welding portion 410 can also be a triangle, parallelogram, trapezoid, pentagon, hexagon, etc.
[0072] In this embodiment, since the overlapping portion 440 protrudes along the length direction y at one end of the connecting portion 420 facing the welding portion 410, and the welding portion 410 has an overlapping groove 412 on its surface along the thickness direction x, when the overlapping portion 440 is disposed in the overlapping groove 412 and bonded or welded to the groove wall of the overlapping groove 412, the contact area between the welding portion 410 and the connecting portion 420 can be increased, thereby increasing the bonding or welding area between the welding portion 410 and the connecting portion 420, thereby further improving the structural strength of the connection between the welding portion 410 and the connecting portion 420, reducing the occurrence of warping or connection detachment at the connection between the welding portion 410 and the connecting portion 420, thereby strengthening the structural strength of the clearance opening 411.
[0073] Example 6
[0074] Reference Figure 11 as well as Figure 12 As shown, in Embodiment 6, the difference between Embodiment 6 and Embodiment 5 is that, in the thickness direction x, the orthographic projection shape of the overlapping portion 440 on the welding portion 410 is arc-shaped.
[0075] In this embodiment, the arc-shaped structure is easier to process than the polygonal structure. This reduces the processing difficulty of the overlapping groove 412 and the overlapping part 440. At the same time, it can reduce the burrs on the groove wall of the overlapping groove 412 and the edge of the overlapping part 440 during processing, reducing the possibility of the connecting piece 400 scratching the electrode tab 310. In addition, the arc-shaped structure can reduce the stress concentration at the connection between the welding part 410 and the connecting part 420, thereby improving the structural stability of the connection between the welding part 410 and the connecting part 420.
[0076] Reference Figure 2 As shown, based on Embodiments 1 to 6, the welding part 410 further has a first welding area 413 and a second welding area 414, with the clearance opening 411 located in the second welding area 414. The pole post 220 is welded to the first welding area 413, and the pole tab 310 is welded to the second welding area 414, thereby realizing the welding of the connecting piece 400 with the pole tab 310 and the pole post 220. At the same time, the pole post 220 and the clearance opening 411 are spaced apart, improving the sealing performance of the receiving cavity.
[0077] Reference Figure 1 As shown, based on Embodiments 1 to 6, the electrode assembly 300 further includes an electrode body 320, which is electrically connected to the tab 310. The electrode body 320 and the tab 220 are electrically connected by connecting piece 400 to connect the tab 310 and the post 220.
[0078] The battery pack involved in the embodiments of this application includes: the above-mentioned battery cells.
[0079] In the battery pack of this application, since the aforementioned battery cells can reduce the probability of deformation after the connecting piece 400 is welded, the aforementioned battery cells can have higher product quality, so that the battery pack of this application can have higher product quality and safety performance.
[0080] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0081] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.
Claims
1. A battery cell, characterized in that, It includes a housing (100), a top cover assembly (200), an electrode assembly (300), and a connecting piece (400); The housing (100) has a receiving cavity; The top cover assembly (200) includes a top cover (210) and an electrode post (220) disposed on the top cover (210). The top cover (210) is connected to the housing (100) and covers the receiving cavity. The top cover (210) is provided with a liquid injection hole (211), which is spaced apart from the electrode post (220). The electrode assembly (300) is located in the receiving cavity, and the electrode assembly (300) has a tab (310) on the side facing the top cover (210); The connecting piece (400) is located in the receiving cavity. The connecting piece (400) is provided with a connecting welding part (410) and a connecting part (420). The welding part (410) has a clearance opening (411) at one end facing the connecting part (420). The connecting part (420) is at least partially connected to the edge of the welding part (410) located at the clearance opening (411). The welding part (410) is welded to the pole post (220) or the pole tab (310). The clearance opening (411) is arranged opposite to the injection hole (211).
2. The battery cell according to claim 1, characterized in that, The welding part (410) and the connecting part (420) are integrally formed.
3. The battery cell according to claim 2, characterized in that, The battery cell has a thickness direction (x), the liquid injection hole (211) and the clearance opening (411) are arranged opposite to each other in the thickness direction (x), the welding part (410) has a size of L1mm in the thickness direction (x), and the connecting part (420) has a size of L2mm in the thickness direction (x), satisfying: L1≤L2.
4. The battery cell according to claim 1, characterized in that, The welding part (410) engages with the connecting part (420).
5. The battery cell according to claim 4, characterized in that, The connecting piece (400) is also provided with a snap-fit part (430), which is located at one end of the welding part (410) facing the connecting part (420) and is spaced apart from the clearance opening (411). The connecting part (420) is provided with a snap-fit hole (421), and the snap-fit part (430) passes through the snap-fit hole (421) to snap-fit the welding part (410) and the connecting part (420).
6. The battery cell according to claim 1, characterized in that, The welding part (410) is bonded or welded to the connecting part (420).
7. The battery cell according to claim 6, characterized in that, The battery cell has intersecting thickness direction (x) and length direction (y). The injection hole (211) and the clearance opening (411) are arranged opposite to each other in the thickness direction (x), and the clearance opening (411) is located at one end of the welding part (410) along the length direction (y). The end of the welding part (410) along the length direction (y) near the clearance opening (411) is bonded or welded to one end of the connecting part (420) along the length direction (y).
8. The battery cell according to claim 7, characterized in that, The connecting piece (400) is also provided with an overlapping portion (440), which is located at one end of the connecting portion (420) facing the welding portion (410) along the length direction (y). The welding portion (410) is provided with an overlapping groove (412) on its surface along the thickness direction (x). The overlapping portion (440) is embedded in the overlapping groove (412) and is bonded or welded to the groove wall of the overlapping groove (412).
9. The battery cell according to claim 8, characterized in that, In the thickness direction (x), the orthographic projection shape of the overlapping portion (440) onto the welded portion (410) is polygonal or arc-shaped.
10. A battery pack, characterized in that, include: The battery cell as described in any one of claims 1-9.