Terminal post, top cover assembly, battery cell, battery, and electrical device

Abstract

The present application relates to a terminal post, a top cover assembly, a battery cell, a battery, and an electrical device. The terminal post comprises at least one first connection portion and at least two second connection portions. The at least two second connection portions are spaced apart from each other in a first preset direction. One first connection portion is provided between every two adjacent second connection portions, and each first connection portion is connected to the two adjacent second connection portions. The first connection portion is configured to be connected to an electrical connector, and a side surface of the first connection portion along a thickness direction of the terminal post is a first surface. Each of the second connection portions extends beyond the first surface of the first connection portion in the thickness direction of the terminal post, and is configured to be connected to a tab.

Description

Terminal posts, top cover assembly, individual battery cells, batteries and electrical devices

[0001] Cross-reference to related applications

[0002] This application claims priority to patent application No. 202510096359.1, filed with the China National Intellectual Property Administration on January 21, 2025, entitled "Terminal Post and Processing Method, Top Cover Assembly, Battery Cell, Battery, and Electrical Device", and patent application No. 202510653188.8, filed with the China National Intellectual Property Administration on May 20, 2025, entitled "Terminal Post, Top Cover Assembly, Battery Cell, Battery, and Electrical Device", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of battery technology, specifically to an electrode post, a top cover assembly, a battery cell, a battery, and an electrical device. Background Technology

[0004] Lithium-ion batteries have advantages such as high energy density, long cycle life, high rate performance, good safety, and environmental friendliness, making them an important energy product for modern electronic products and electric vehicles. The battery cell is a crucial component of the battery.

[0005] There are two technical solutions for battery cells: those with adapter plates and those without. In the adapter plate solution, the tabs of the cell are led out to the terminals via the adapter plate, making the terminals the electrode terminals of the battery cell. However, the presence of the adapter plate increases the number of parts, thus increasing battery cost; furthermore, it adds a welding process between the tabs and the adapter plate, further increasing battery cost.

[0006] In adapter-less designs, the terminals and tabs are directly connected. However, due to limited space on the cover plate, the position of the terminals is restricted, necessitating the use of extended tabs to achieve direct connection. Extending the tabs significantly increases the risk of the tabs being inserted backwards into the cell and of tearing. Furthermore, the design dimensions of the terminals are also limited, resulting in weaker current-carrying capacity, which is detrimental to improving the battery's charge / discharge performance and safety.

[0007] Application content

[0008] Therefore, it is necessary to provide a terminal post, top cover assembly, battery cell, battery, and power device that can eliminate the need for adapters and avoid lengthening the electrode tabs, in order to address the above problems.

[0009] One embodiment of this application provides an electrode post, including at least one first connecting portion and at least two second connecting portions. The at least two second connecting portions are arranged at intervals along a first preset direction. A first connecting portion is provided between each pair of adjacent second connecting portions, and each first connecting portion is connected to the two adjacent second connecting portions. The first connecting portion is used to connect with an electrical connector, and one side of the first connecting portion in a third preset direction is a third surface. Each second connecting portion extends beyond the third surface of the first connecting portion along the third preset direction, and the second connecting portion is used to connect with an electrode tab. The third preset direction intersects with the first preset direction.

[0010] In some embodiments, on a dummy plane perpendicular to a third preset direction, the orthographic projection of the first connecting portion does not overlap with the orthographic projection of each of the second connecting portions.

[0011] In some embodiments, there are two second connecting portions, which are respectively connected to the two sides of the first connecting portion in a first preset direction.

[0012] In some embodiments, each second connecting portion includes a first region and a second region surrounding the first region, the second region being connected to the first connecting portion, the first region protruding relative to the second region along a third preset direction to form a connecting sub-portion; the side surface of the second region facing away from the connecting sub-portion in the third preset direction is a fourth surface, and the side surface of the connecting sub-portion facing away from the second region in the third preset direction is a second surface.

[0013] In some embodiments, the connector has a first groove, and the opening of the first groove extends through one end of the connector away from the second surface.

[0014] In some embodiments, in a third preset direction, the bottom of the first groove is located on the side of the first surface away from the third surface.

[0015] In some embodiments, the second region includes a first straight section, a first arc section, a second straight section, and a second arc section connected end to end in sequence. The first straight section and the second straight section are respectively located on both sides of the first region in a first preset direction, and the first arc section and the second arc section are respectively located on both sides of the first region in a second preset direction. The first preset direction, the second preset direction, and the third preset direction are perpendicular to each other.

[0016] In some embodiments, the first connecting portion has a boss and an annular surface on the side opposite to the first surface; the annular surface is arranged around the boss, and the boss protrudes from the annular surface in a direction away from the first surface.

[0017] In some embodiments, the protrusion height H1 of the boss relative to the annular surface is 0.05 mm to 0.8 mm.

[0018] In some embodiments, the pole includes a first metal layer and a second metal layer, the first metal layer extending to a first connection portion and each of the second connection portions; at each of the second connection portions, the second metal layer and the first metal layer are stacked together along a third preset direction, and the side surface of the first metal layer away from the second metal layer includes a fourth surface, the side surface of the second metal layer away from the first metal layer is a sixth surface, and the sixth surface includes the second surface.

[0019] In some embodiments, the connecting sub-part has a first groove, and the opening of the first groove passes through one end of the connecting sub-part away from the second surface; the connecting sub-part has a bottom wall and an annular side wall, one end of the annular side wall is connected to the second region, and the bottom wall is connected to the other end of the annular side wall, the annular side wall and the bottom wall together enclose to form the first groove; the thickness of the second metal layer at the annular side wall is T7, the thickness of the second metal layer at the second region is T3, and the thickness of the second metal layer at the bottom wall is T5, T7, T5 and T3 satisfy: T5≥T3>T7.

[0020] In some embodiments, the thickness T5 of the second metal layer at the bottom wall is 0.3 mm to 1.8 mm; and / or, the thickness T5 of the second metal layer at the bottom wall accounts for 10% to 40% of the thickness of the bottom wall. In some embodiments, the first connecting portion includes a base portion and a first electrical connecting portion, the base portion having the third surface, and along the third preset direction, the base portion having a first surface opposite to the third surface, the first electrical connecting portion being disposed on the surface of the base portion having the first surface; the second connecting portion includes a main body portion and a first flange portion, the first flange portion being connected to one end face of the main body portion along the third preset direction and extending toward the base portion, the first flange portion being connected to the base portion, and along the third preset direction, the first flange portion having a second surface, the second surface and the first surface being located on the same side in the thickness direction of the pole post, and the second surface and the first surface being in the same plane and forming a surface.

[0021] In some embodiments, along the third preset direction, the first flange portion has a fourth surface disposed opposite to the second surface, the third surface and the fourth surface being in the same plane and forming a surface.

[0022] In some embodiments, the second connecting portion further includes a second flange portion, which is connected to one end face of the main body portion along the third preset direction and extends away from the base portion. The second flange portion is disposed opposite to the first flange portion along the first preset direction. Along the third preset direction, the second flange portion has a fifth surface, which is in the same plane as the surface and forms a surface. Along the third preset direction, the second flange portion also has a sixth surface disposed opposite to the fifth surface, which is in the same plane as the surface and forms a surface, wherein the surface and the surface are parallel.

[0023] In some embodiments, the second connecting portion further includes a third flange portion and a fourth flange portion. Along a second preset direction, the third flange portion connects one end of the first flange portion and the second flange portion, and the fourth flange portion connects the other end of the first flange portion and the second flange portion. The second preset direction, the first preset direction, and the third preset direction are arranged to intersect each other.

[0024] In some embodiments, both the third flange and the fourth flange are arc-shaped.

[0025] In some embodiments, the second connecting portion includes a first metal layer and a second metal layer, which are stacked along the direction from the surface to the surface, wherein at least a portion of the interface between the first metal layer and the second metal layer intersects with the sidewall surface of the second flange portion.

[0026] In some embodiments, the first connecting portion includes the first metal layer, and the first metal layer and the second metal layer of the second connecting portion are both connected to the first metal layer of the first connecting portion.

[0027] In some embodiments, the first connecting portion includes a first metal layer and a second metal layer stacked together, wherein the first metal layer of the second connecting portion is connected to the first metal layer of the first connecting portion, and the second metal layer of the second connecting portion is connected to the second metal layer of the first connecting portion.

[0028] In some embodiments, the main body includes an annular sidewall and a bottom wall. Along the third preset direction, one end of the annular sidewall is connected to the first flange, and the other end of the annular sidewall is connected to the bottom wall. The thickness T5 of the second metal layer at the bottom wall is 0.3 mm to 1.8 mm; and / or, the thickness T5 of the second metal layer at the bottom wall accounts for 10% to 40% of the thickness of the bottom wall.

[0029] In some embodiments, the first metal layer is an aluminum layer and the second metal layer is a copper layer.

[0030] In some embodiments, along the first preset direction, the distance between the side of the first flange and the side of the main body is c, satisfying: 0.5mm≤c≤5mm; and / or, along the first preset direction, the distance between the side of the second flange and the side of the main body is d, satisfying: 0.5mm≤d≤5mm; and / or, along the first preset direction, the distance c between the side of the first flange and the side of the main body is less than the distance d between the side of the second flange and the side of the main body; and / or, along the second preset direction, the minimum distance between the edge side of the first electrical connection and the edge side of the base is a, satisfying: 0.2mm≤a≤5mm; and / or, along the third preset direction, the distance between the upper and lower surfaces of the base is W5, satisfying: 0.5mm≤W5≤3mm.

[0031] In some embodiments, the pole further includes a fusible portion connected between the first connecting portion and the second connecting portion. Along the third preset direction, the fusible portion has a seventh surface and an eighth surface disposed opposite to each other, wherein the seventh surface is in the same plane as the surface; and / or, the eighth surface is in the same plane as the surface.

[0032] In some embodiments, the first electrical connection portion includes a first sub-part and a second sub-part. Along the third preset direction, one end of the first sub-part is connected to the base portion, and the other end is connected to the second sub-part. Along the third preset direction, on a plane perpendicular to the third preset direction, the orthographic projection of the second sub-part falls within the orthographic projection range of the first sub-part. A second stepped surface is connected between the sidewall of the first sub-part and the sidewall of the second sub-part, and the surface of the second sub-part away from the first sub-part is the first electrical connection surface.

[0033] In some embodiments, on a plane perpendicular to the third preset direction, the width of the second step surface is W3, satisfying: 0.3mm≤W3≤1mm; and / or, along the third preset direction, the distance between the second step surface and the first electrical connection surface is W4, satisfying: 0.2mm≤W4≤0.7mm; and / or, along the third preset direction, the distance between the second step surface and the first electrical connection surface is W4, and the distance between the first electrical connection surface and the surface is W6, satisfying: 15%≤W4 / W6≤50%; and / or, along the first preset direction, the maximum width of the first electrical connection portion is W1, and on a plane perpendicular to the third preset direction, the width of the second step surface is W3, satisfying: 1%≤W3 / W1≤10%.

[0034] In some embodiments, the main body includes a third sub-part and a fourth sub-part. Along the third preset direction, one end of the third sub-part is connected to the first flange, and the other end is connected to the fourth sub-part. Along the third preset direction, on a plane perpendicular to the third preset direction, the orthographic projection of the fourth sub-part falls within the orthographic projection range of the third sub-part. A third stepped surface is connected between the sidewall of the fourth sub-part and the sidewall of the third sub-part. The surface of the fourth sub-part away from the third sub-part is a second electrical connection surface.

[0035] In some embodiments, on a plane perpendicular to the third preset direction, the width of the third step surface is W7, satisfying: 0.3mm≤W7≤1mm; and / or, along the third preset direction, the distance between the third step surface and the second electrical connection surface is W8, satisfying: 0.2mm≤W8≤0.7mm; and / or, along the first preset direction, the width of the second electrical connection surface is W9, and on a plane perpendicular to the third preset direction, the width of the third step surface is W7, satisfying: 2%≤W7 / W9≤20%.

[0036] In some embodiments, the second connecting portion has a first groove that is recessed from the surface into the body portion.

[0037] In some embodiments, along the third preset direction, the bottom surface of the first groove is located on the side of the third surface away from the first surface.

[0038] In some embodiments, along the third preset direction, the first flange portion has a fourth surface disposed opposite to the second surface, and on a plane perpendicular to the second preset direction, the angle between the groove wall surface of the first groove near the base portion and the fourth surface is β, satisfying: 90°≤β≤95°.

[0039] In some embodiments, the main body includes an annular sidewall and a bottom wall. Along the third preset direction, one end of the annular sidewall is connected to the first flange, and the other end of the annular sidewall is connected to the bottom wall. In the direction from the end connected to the first flange to the other end, the outer contour dimension of the annular sidewall gradually decreases or decreases in a stepwise manner.

[0040] In some embodiments, along the third preset direction, the first flange portion has a fourth surface disposed opposite to the second surface, and on a plane perpendicular to the second preset direction, the angle between the side wall surface of the main body portion near the base portion and the fourth surface is α, satisfying: 90°≤α≤95°.

[0041] In some embodiments, the first connecting portion and the second connecting portion are integrally formed.

[0042] In some embodiments, along the first preset direction, the maximum width of the first electrical connection portion is W1, satisfying: 8mm≤W1≤35mm; and / or, along the first preset direction, the maximum width of the pole post is W2, satisfying: 14mm≤W2≤80mm; and / or, along the first preset direction, the maximum width of the first electrical connection portion is W1, and the maximum width of the pole post is W2, satisfying: 20%≤W1 / W2≤60%; and / or, along the third preset direction, the distance between the first electrical connection surface of the first electrical connection portion and the surface is W6, satisfying: 0.7mm≤W6≤2mm; and / or, along the second preset direction, the base of the first connection portion... The maximum length of the body portion is W10, satisfying: 15mm≤W10≤50mm; and / or, along the second preset direction, the maximum length of the base portion of the first connecting portion is W10, and the maximum length of the first electrical connecting portion is W11, satisfying: 85%≤W11 / W10≤98%; and / or, along the second preset direction, the maximum length of the base portion of the first connecting portion is W10, and the maximum length of the second connecting portion is W12, satisfying: 80%≤W10 / W12≤100%; and / or, along the first preset direction, the maximum width of the first electrical connecting portion is W1, and the maximum width of the body portion is W13, satisfying: 35%≤W13 / W1≤75%.

[0043] In the above embodiments, optionally, the second surface is located between the first electrical connection surface and the third surface in the thickness direction of the electrode post.

[0044] Other embodiments of this application provide a top cover assembly, including a cover plate and the aforementioned pole post; a first through hole is provided on the cover plate, a first connecting portion is disposed on one side of the cover plate, the third surface of the first connecting portion faces the cover plate, and at least a portion of the second connecting portion passes through the first through hole.

[0045] Other embodiments of this application provide a battery cell including a housing, a cell assembly, and the aforementioned top cover assembly; the housing has an opening at at least one end, the cell assembly is housed within the housing, the top cover assembly covers the opening, and the thickness direction of the housing is consistent with a first preset direction; the cell assembly includes at least two sets of cells arranged side by side along the thickness direction of the housing, and the at least two sets of cells are configured to correspond one-to-one with at least two second connecting portions, the end face of each set of cells extends out to form a tab, and the tab of each set of cells is respectively connected to the corresponding second connecting portion.

[0046] Other embodiments of this application provide a battery cell including a housing, a cell assembly and the aforementioned terminals, with the terminals disposed on the housing and the cell assembly housed within the housing.

[0047] Other embodiments of this application provide a battery including a plurality of the above-described battery cells, the plurality of battery cells being electrically connected by an electrical connector, the electrical connector being connected to a first connection portion.

[0048] Other embodiments of this application provide an electrical device, including the battery cell described above, or the battery described above.

[0049] Compared with related technologies, this application has the following advantages:

[0050] In the aforementioned terminal posts, top cover assembly, battery cells, batteries, and electrical devices, the terminal posts are directly connected to the tabs of the two sets of battery cells through two second connecting parts. On the one hand, this avoids the use of adapter plates, thereby reducing the number of parts in the top cover assembly and eliminating one welding process. On the other hand, by arranging the two second connecting parts along the arrangement direction of the two sets of battery cells, the two second connecting parts pass through the first through hole on the cover plate and are connected to the tabs of the two sets of battery cells respectively, avoiding the need to extend the tabs and thus greatly reducing the risk of adverse phenomena such as tabs being inserted backward into the battery cells and tabs being torn. Attached Figure Description

[0051] Figure 1 is a cross-sectional view of a single battery cell in one embodiment of this application;

[0052] Figure 2 is a schematic diagram of the top cover assembly in one embodiment of this application;

[0053] Figure 3 is a top view of the top cover assembly shown in Figure 2;

[0054] Figure 4 is a schematic diagram of the pole structure of the top cover assembly shown in Figure 2;

[0055] Figure 5 is a top view of the pole shown in Figure 4;

[0056] Figure 6 is a bottom view of the pole shown in Figure 5;

[0057] Figure 7 is a cross-sectional view of the top cover assembly shown in Figure 2 at the pole post (the cross-section is perpendicular to the length direction of the cover plate);

[0058] Figure 8 is a cross-sectional view of the pole of the top cover assembly shown in Figure 7 (the cross-section is perpendicular to the length direction of the cover plate);

[0059] Figure 9 is a cross-sectional view of the top cover assembly in another embodiment of this application (the cross-section is perpendicular to the length direction of the cover plate);

[0060] Figure 10 is a cross-sectional view of the pole of the top cover assembly shown in Figure 9 (the cross-section is perpendicular to the length direction of the cover plate);

[0061] Figure 11 is a cross-sectional view of the top cover assembly in another embodiment of this application (the cross-section is perpendicular to the length direction of the cover plate);

[0062] Figure 12 is a cross-sectional view of the top cover assembly in another embodiment of this application (the cross-section is perpendicular to the length direction of the cover plate);

[0063] Figure 13 is a three-dimensional structural diagram of a battery cell provided in an embodiment of this application;

[0064] Figure 14 is a front view structural diagram of a battery cell provided in an embodiment of this application;

[0065] Figure 15 is a cross-sectional view of AA in Figure 14;

[0066] Figure 16 is a cross-sectional view of BB in Figure 14;

[0067] Figure 17 is a front view of the top cover assembly provided in an embodiment of this application;

[0068] Figure 18 is a cross-sectional view of AA in Figure 17;

[0069] Figure 19 is a cross-sectional view of BB in Figure 17;

[0070] Figure 20 is an exploded disassembly diagram of the top cover assembly provided in an embodiment of this application;

[0071] Figure 21 is a three-dimensional structural diagram of the pole post in the top cover assembly provided in the embodiment of this application;

[0072] Figure 22 is a side view of the pole post in the top cover assembly provided in an embodiment of this application;

[0073] Figure 23 is a side view of the pole post in the top cover assembly provided in the embodiment of this application;

[0074] Figure 24 is a top view of the pole post in the top cover assembly provided in the embodiment of this application;

[0075] Figure 25 is the CC cross-sectional view in Figure 24;

[0076] Figure 26 is a three-dimensional structural diagram of the pole post in the top cover assembly provided in another embodiment of this application;

[0077] Figure 27 is a side view of the pole post in the top cover assembly provided in another embodiment of this application;

[0078] Figure 28 is a top view of the pole post in the top cover assembly provided in another embodiment of this application;

[0079] Figure 29 is a cross-sectional view of DD in Figure 28;

[0080] Figure 30 is a three-dimensional structural diagram of the pole post in the top cover assembly provided in another embodiment of this application;

[0081] Figure 31 is a side view of the pole post in the top cover assembly provided in another embodiment of this application;

[0082] Figure 32 is a side view of the pole post in a top cover assembly provided in another embodiment of this application;

[0083] Figure 33 is a top view of the pole post in the top cover assembly provided in another embodiment of this application;

[0084] Figure 34 is a cross-sectional view of AA in Figure 33;

[0085] Figure 35 is a three-dimensional structural diagram of the pole post in the top cover assembly provided in another embodiment of this application;

[0086] Figure 36 is a side view of the pole post in the top cover assembly provided in another embodiment of this application;

[0087] Figure 37 is a top view of the pole post in the top cover assembly provided in another embodiment of this application;

[0088] Figure 38 is a cross-sectional view of BB in Figure 37.

[0089] 1. Battery cell; 10. Cover plate; 11. First through hole; 12. Flanged structure; 13. Third groove; 14. Fifth groove;

[0090] 20. First insulating element; 210. Third insulating part; 220. Second insulating part; 230. First insulating part; 21. First insulator part; 22. Second insulator part; 223. First stepped surface; 225. Fourth groove; 23. Third insulator part;

[0091] 30. Pole post; 31. First connecting part; 311. Boss; 312. Annular surface; 315. Second groove; 3110. Base part; 3111. First surface; 3112. Third surface; 3120. First electrical connection part; 3121. Second stepped surface; 3122. First electrical connection surface; 3123. First sub-part; 3124. Second sub-part;

[0092] 32. Second connecting part; 321. First region; 322. Second region; 323. First groove; 32301. Groove bottom surface; 324. Connecting part; 3245. Annular sidewall; 3247. Bottom wall; 326. First metal layer; 327. Second metal layer; 3210. First flange; 3211. Second surface; 3212. Fourth surface; 3220. Second flange; 3221. Fifth surface; 3222. Sixth surface; 3230. Main body; 3231. Third Step surface; 3232, Second electrical connection surface; 3233, Third sub-part; 3234, Fourth sub-part; 3235, Second sidewall; 3236, Third sidewall; 3237, First sidewall; 3238, Fourth sidewall; 3240, Second electrical connection part; 3250, First arc segment; 3260, Second arc segment; 3270, Third arc segment; 3280, Fourth arc segment; 3290, Fifth arc segment; 32110, Third flange part; 32120, Fourth flange part;

[0093] 33. Transition section; 330. Second through hole; 332. Arc-shaped section; 34. Protrusion; 35. Fusible section; 3510. Seventh surface; 3520. Eighth surface;

[0094] 40. Sealing ring; 41. First sealing part; 43. Second sealing part;

[0095] 50. Second insulating component; 501. Third through hole;

[0096] 100. Top cover assembly; 200. Housing;

[0097] 300. Battery cell assembly; 301. Battery cell; 302. Electrode tab;

[0098] 7. Pressure relief mechanism; 71. Protective layer. Detailed Implementation

[0099] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0100] One embodiment of this application provides an electrical device, a battery, and a battery cell. The electrical device utilizes the following batteries or battery cells as its power source: vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, power tools, energy storage devices, amusement equipment, elevators, and lifting equipment, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, or electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.; energy storage devices can be energy storage walls, base station energy storage, container energy storage, etc.; amusement equipment can be carousels, drop towers, etc. This application does not impose any special limitations on the above-mentioned electrical devices.

[0101] The aforementioned battery can be a battery pack or a battery module. When the battery is a battery pack, the battery pack specifically includes a battery management system (BMS) and multiple battery cells. Multiple battery cells can be electrically connected in series, parallel, or a combination of series and parallel connections, and communicate with the battery management system, which controls and monitors the operating status of each battery cell. Alternatively, multiple battery cells can first be combined with a module management system to form a battery module, and then these battery modules can be electrically connected in series, parallel, or a combination of series and parallel connections to form a battery pack together with the battery management system.

[0102] Multiple battery cells can be mounted on supporting structures such as housings, frames, and brackets. Electrical connections between battery cells and between battery cells and the battery management system can be established via electrical connectors, which can be busbars. Alternatively, battery cells can be electrically connected by inserting their respective terminals. For example, between two adjacent battery cells, one battery cell has a slot on its terminal, and the other battery cell has a corresponding insert on its terminal. The insert is inserted into the slot to achieve electrical connection. Therefore, for one battery cell, the aforementioned electrical connector can be the terminal of another battery cell. Similarly, battery cells and the battery management system can also be electrically connected by mutual insertion, which will not be elaborated further. The aforementioned battery cells can be lithium-ion, sodium-ion, or magnesium-ion batteries, and their external contours can be cylindrical, flat, cuboid, or other shapes, but are not limited to these. In this embodiment, the aforementioned battery cell is a lithium-ion square battery.

[0103] Referring to Figure 1, in this embodiment, the battery cell 1 includes a top cover assembly 100, a housing 200, and a cell assembly 300. The housing 200 has a hollow structure, with internal space for accommodating the cell assembly 300, electrolyte, and other components. At least one end of the housing 200 has an opening through which the cell assembly 300 can be installed. Since the battery cell 1 in this embodiment is a prismatic battery, the outer contour of the housing 200 is cuboid, and its opening is rectangular. The top cover assembly 100 is mounted on the housing 200 and covers the opening of the housing 200, thereby enclosing the cell assembly 300 within the housing 200. Because the shape of the top cover assembly 100 needs to match the shape of the opening of the housing 200, the top cover assembly 100 is generally rectangular.

[0104] The cell assembly 300 is the core component of the battery cell 1. To adapt to the shape of the casing 200, the cell assembly 300 in this embodiment is rectangular. The cell assembly 300 generally includes at least two sets of cells 301 arranged side-by-side along the thickness direction of the casing 200, each set of cells 301 extending out with tabs 302. Each set of cells 301 may contain one or more cells 301. The cells 301 can be formed by winding or stacking positive electrode plates, negative electrode plates, and a separator that acts as an insulator between the negative and positive electrode plates. The wound cells 301 can be pressed into a flat shape. The tabs 302 of each cell 301 are divided into a positive tab (not shown) and a negative tab (not shown), which extend from the positive and negative electrode plates, respectively.

[0105] In this embodiment, the positive and negative tabs can be located at the same end of the battery cell 301, or the positive tab can be located at one end of the battery cell 301 and the negative tab at the opposite end of the battery cell 301. In this embodiment, the battery cell assembly 300 includes two sets of battery cells 301, each set including one battery cell 301. The positive and negative tabs of each battery cell 301 are located at the same end of the battery cell 301 and are spaced apart along the length direction of the battery cell assembly 300, i.e., the length direction of the housing 200. Therefore, one end of the battery cell assembly 300 has a total of four sets of tabs 302, of which two sets are negative tabs spaced apart along the width direction of the housing 200, and the other two sets are positive tabs spaced apart along the width direction of the housing 200. The two sets of negative tabs and the two sets of positive tabs are spaced apart along the length direction of the housing 200. When each group of cells 301 includes multiple cells 301, the positive tabs of the multiple cells 301 are brought together to form a group of positive tabs, and the negative tabs are brought together to form a group of negative tabs. The width direction of the aforementioned housing 200 is also its thickness direction, and the width direction of the cell assembly 300 is also its thickness direction.

[0106] Before the battery cell assembly 300 is installed into the housing 200, it needs to be assembled with the top cover assembly 100. In this embodiment, the tabs 302 of the battery cell assembly 300 need to be electrically connected to the terminals 30 on the top cover assembly 100 (see Figure 2) before the battery cell assembly 300 is installed into the housing 200. This operation is not limited by the small space inside the housing 200.

[0107] In this embodiment, the battery cell assembly 300 includes two sets of battery cells 301, each set of battery cells 301 includes one battery cell 301. That is, the battery cell assembly 300 includes a total of two battery cells 301, and the two battery cells 301 are arranged side by side along the thickness direction of the housing 200.

[0108] The specific structure of the top cover assembly will be described in detail below with reference to the accompanying drawings.

[0109] Please refer to Figures 1 to 4. In this embodiment of the application, the top cover assembly 100 includes a cover plate 10 and a pole post 30. The cover plate 10 covers the opening of the housing 200 to seal the opening. The cover plate 10 can be formed from a material with high mechanical strength, such as aluminum, aluminum alloy, or stainless steel. In this embodiment, the cover plate 10 is generally rectangular to match the shape of the opening of the housing 200. A first through hole 11 is provided on the cover plate 10, and the pole post 30 is mounted on the cover plate 10 through the first through hole 11.

[0110] The terminal post 30 is disposed on the cover plate 10, and the thickness direction Z of the terminal post 30 is consistent with the thickness direction of the cover plate 10. Since the positive and negative terminals of the cell assembly 300 are located at the same end, the cover plate 10 is provided with mutually spaced positive and negative terminals along its length. The positive terminal post is used to connect to the positive terminal of each group of cells 301, and the negative terminal post is used to connect to the negative terminal of each group of cells 301. Of course, if the positive and negative terminals are located at opposite ends of the cell assembly 300, only one of the positive and negative terminals needs to be provided on the cover plate 10. The positive terminal post serves as the positive terminal of the battery cell 1, and the negative terminal post serves as the negative terminal of the battery cell 1. The positive and negative terminals of each battery cell 1 are connected using electrical connectors to realize series, parallel, or mixed connection of the battery cells 1. The electrical connectors can be busbars or terminals 30 of other battery cells 1.

[0111] It should be noted that, due to the similarity in structure between the positive and negative terminals, this article will use one of the terminals, 30, as an example for ease of understanding. That is, the term "terminal" in this article can be either a positive or negative terminal (unless explicitly stated otherwise), and the term "tab" can be either a positive or negative tab (unless explicitly stated otherwise), as long as all tabs connected to the positive terminal are positive tabs and all tabs connected to the negative terminal are negative tabs.

[0112] In this embodiment, the electrode post 30 includes a first connecting portion 31 and two second connecting portions 32. The two second connecting portions 32 are arranged at intervals along a first preset direction X. A first connecting portion 31 is provided between the two second connecting portions 32, and the first connecting portion 31 is connected to the two adjacent second connecting portions 32. The first connecting portion 31 is provided on the side of the cover plate 10 away from the cell assembly 300 (i.e., the outer side of the cover plate 10) and is used to connect with the electrical connector. The aforementioned first preset direction X is consistent with the thickness direction of the housing 200, that is, the arrangement direction of the two second connecting portions 32 is consistent with the arrangement direction of the two sets of cells 301, so that the two second connecting portions 32 correspond one-to-one with the tabs 302 of the two sets of cells 301. At least a portion of each second connecting portion 32 passes through the first through hole 11 on the cover plate 10 and is connected to the corresponding tab 302, thereby realizing the direct connection between the electrode post 30 and each tab 302.

[0113] In this embodiment, the side of the first connecting portion 31 facing the cover plate 10 is the first surface b1. Both second connecting portions 32 extend beyond the first surface b1 of the first connecting portion 31 along the thickness direction of the electrode post 30, causing the two second connecting portions 32 to protrude relative to the first connecting portion 31 facing the cover plate 10. This allows the two second connecting portions 32 to penetrate through the first through hole 11 on the cover plate 10 to the side of the cover plate 10 facing the cell assembly 300 (i.e., the inner side of the cover plate 10), and then connect one-to-one with the tabs 302 of the two sets of cells 301. In other words, the tabs 302 of the two sets of cells 301 are connected one-to-one with the two second connecting portions 32, and the two second connecting portions 32 are electrically connected to the first connecting portion 31, making the first connecting portion 31 an electrode terminal of the battery cell 1.

[0114] In the aforementioned top cover assembly 100, the pole post 30 is directly connected to the tabs 302 of the two sets of battery cells 301 via two second connecting parts 32. This avoids the use of adapter plates, thereby reducing the number of parts in the top cover assembly 100 and eliminating one welding process. Furthermore, by arranging the two second connecting parts 32 along the arrangement direction of the two sets of battery cells 301, the two second connecting parts 32 pass through the first through hole 11 on the cover plate 10 and are respectively connected to the tabs 302 of the two sets of battery cells 301. This avoids the need to extend the tabs 302, thereby greatly reducing the risk of adverse phenomena such as the tabs 302 being inserted backwards into the battery cells 301 and the tabs 302 being torn.

[0115] It should be noted that, in order to enable the electrode post 30 to be directly connected to the electrode tab 302, related technologies have adopted the method of directly increasing the diameter of the electrode post 30. However, in this application, by arranging the two second connecting parts 32 along the arrangement direction of the two sets of cells 301, the two second connecting parts 32 can pass through the first through hole 11 on the cover plate 10 and be directly electrically connected to their respective electrode tabs 302, thus avoiding the need to increase the diameter of the electrode post 30, which helps to save electrode post 30 material and reduce electrode post 30 cost.

[0116] It should also be noted that the number of first connecting parts 31 is not limited to one; it can be two or more. Similarly, the number of second connecting parts 32 is not limited to two; it can be three or more. The number of first connecting parts 31 and second connecting parts 32 is related to the number of groups of battery cells 301. If there are N groups of battery cells 301, the number of second connecting parts 32 is also set to N. These N second connecting parts 32 are arranged at intervals along a first preset direction X. A first connecting part 31 is provided between every two adjacent second connecting parts 32, and each pair of adjacent second connecting parts 32 is connected to the first connecting part 31 between them; that is, there are N-1 first connecting parts 31. The N second connecting parts 32 respectively pass through the first through holes 11 on the cover plate 10 and are connected one-to-one with the tabs 302 of each group of battery cells 301. It should be noted that the number of groups of battery cells 301 is not the same as the quantity of battery cells 301. For example, a battery cell assembly 300 may include four battery cells 301. Two battery cells 301 form one group, with their tabs 302 joined together to form a single tab 302, which is connected to a second connection part 32. The other two battery cells 301 form another group, with their tabs 302 joined together to form a single tab 302, which is connected to another second connection part 32. In this case, there are two groups of battery cells 301, but the quantity of battery cells 301 is four; the two are not the same. For ease of understanding, this article will use the example of a battery cell assembly 300 including two groups of battery cells 301, each group including one battery cell 301, and a terminal 30 including a first connection part 31 and two second connection parts 32.

[0117] In this embodiment, the first through hole 11 on the cover plate 10 can be a single through hole with a large opening range, allowing at least two second connecting parts 32 to pass through together; the first through hole 11 can also be a through hole with a small opening range, allowing only one second connecting part 32 to pass through each first through hole 11. Referring to Figure 3, a first through hole 11 is provided on the cover plate 10 at the position corresponding to each of the two second connecting parts 32, so that the two second connecting parts 32 respectively pass through the first through hole 11 corresponding to them, and then connect to the two tabs 302 on the inner side of the cover plate 10 respectively.

[0118] In this embodiment, the first through hole 11 is a through hole with a small opening range, and the area of ​​the cover plate 10 corresponding to the first connecting part 31 does not need to be opened. Therefore, the opening area on the cover plate 10 can be reduced, thereby avoiding a significant decrease in the structural strength of the cover plate 10 due to the opening.

[0119] Taking Figure 3 as an example, the cover plate 10 has four first through holes 11. Two of the first through holes 11 are located at one end of the length direction of the cover plate 10 and are spaced apart along the width direction of the cover plate 10. The other two first through holes 11 are located at the other end of the length direction of the cover plate 10 and are also spaced apart along the width direction of the cover plate 10.

[0120] In this embodiment, the first connecting portion 31 does not overlap with the first through hole 11 in the thickness direction of the cover plate 10. That is, the orthographic projection of the first connecting portion 31 on the cover plate 10 is located in the area outside the first through hole 11 and does not overlap with the first through hole 11.

[0121] In this embodiment, the distance F2 between the ends of the two second connecting portions 32 of the pole post 30 that are far apart from each other (i.e., the length dimension F2 of the pole post 30 in the first preset direction X) is 20mm to 70mm. Thus, since the width dimension of the cover plate 10 (i.e., the dimension of the cover plate 10 in the first preset direction X) is limited, by setting F2 between 20mm and 70mm, on the one hand, it ensures that the two second connecting portions 32 are as close as possible to the two sides of the cover plate 10 in the first preset direction X. Since the tabs 302 of the two sets of cells 301 are respectively located close to the two sides of the cover plate 10 in the width direction, the two second connecting portions 32 are as close as possible to their respective tabs 302, thereby reducing the required length of the tabs 302 and avoiding the need to extend the length of the tabs 302. On the other hand, the length of the pole post 30 is moderate, ensuring that the electrical connection area between the second connecting portion 32 and the tab 302, and the electrical connection area between the first connecting portion 31 and the electrical connector are sufficiently large to better meet the overcurrent requirements, while also saving materials and reducing costs.

[0122] In some other embodiments, the distance between the ends of the two second connecting portions 32 that are far apart from each other is F2 = (F1-30mm) to (F1-10mm), where F1 represents the width dimension of the cover plate 10 (i.e. the dimension of the cover plate 10 in the first preset direction X). Thus, since the width of the cover plate 10, the arrangement direction of the two sets of battery cells 301, and the arrangement direction of the two second connecting parts 32 are consistent, the spacing value F2 is designed according to the width of the cover plate 10. On the one hand, the two second connecting parts 32 can be as close as possible to the two sides of the cover plate 10 in the first preset direction X. Since the tabs 302 of the two sets of battery cells 301 are located close to the two sides of the cover plate 10 in the width direction, the two second connecting parts 32 are as close as possible to their respective tabs 302, thereby ensuring that the required length of the tabs 302 is small and avoiding the need to extend the length of the tabs 302. On the other hand, the length of the pole 30 is moderate, which can ensure that the electrical connection area between the second connecting part 32 and the tab 302, and the electrical connection area between the first connecting part 31 and the electrical connector are large enough to better meet the overcurrent requirements, and can also save materials and reduce costs.

[0123] In this embodiment, the dimension F3 of each second connection part 32 in the first preset direction X satisfies: 3mm≤F3≤1 / 2×F2, thereby ensuring that the electrical connection area between the second connection part 32 and the tab 302 is large enough to meet the overcurrent requirements, while also saving materials and reducing costs.

[0124] In this embodiment, the dimension F6 of each second connecting portion 32 in the second preset direction Y is 20mm to 60mm. The first preset direction X, the second preset direction Y, and the thickness direction Z of the pole post 30 intersect each other; preferably, the first preset direction X, the second preset direction Y, and the third preset direction Z are perpendicular to each other, that is, the first preset direction X is the width direction of the cover plate 10, the second preset direction Y is the length direction of the cover plate 10, and the thickness direction Z of the pole post 30 is consistent with the thickness direction of the cover plate 10. In this way, by setting F6 between 20mm and 60mm, the connection area between the second connecting portion 32 and the corresponding tab 302 is large enough, saving materials and reducing costs as much as possible while meeting the overcurrent requirements.

[0125] In this embodiment, the dimension F7 of the first connecting portion 31 in the second preset direction Y is smaller than F6. Specifically, F7 = (40%~90%)F6. If the dimension F7 is too small, the connection area between the first connecting portion 31 and the electrical connector is too small, which is not conducive to current flow. If the dimension F7 is too large, the original sheet material required to form the electrode post 30 is too large, increasing the weight of the electrode post 30 and wasting material. Therefore, limiting the ratio of F7 to F6 within a suitable range ensures that the connection area between the first connecting portion 31 and the electrical connector is large enough, thereby minimizing the weight of the electrode post 30, saving material, and reducing costs while meeting current flow requirements.

[0126] Of course, in other embodiments, the dimension F7 of the first connecting portion 31 in the second preset direction Y can also be set to be equal to the dimension F6 of the second connecting portion 32 in the second preset direction Y, which is not limited here.

[0127] In this embodiment, two second connecting portions 32 are symmetrically arranged on both sides of the first connecting portion 31. Referring to Figure 7, the distance J from the central axis of the second connecting portion 32 to the edge of the cover plate 10 is 4mm to 17mm. The distance K between the central axis of the first connecting portion 31 and the central axis of the second connecting portion 32 is 0.5mm to 2mm. By setting J and K within a reasonable range, on the one hand, the required length of the tab 302 is kept small, avoiding the need to extend the length of the tab 302; on the other hand, the length of the pole post 30 is moderate, ensuring that the electrical connection area between the second connecting portion 32 and the tab 302, and the electrical connection area between the first connecting portion 31 and the electrical connector, are sufficiently large to better meet the overcurrent requirements, while also saving materials and reducing costs.

[0128] Referring to Figures 4 to 8, in the embodiments of this application, the first connecting portion 31 further has a third surface b3 opposite to the first surface b1, and each second connecting portion 32 has a second surface b2 and a fourth surface b4 on both sides of the pole post 30 in the thickness direction Z. The second surface b2 and the first surface b1 are located on the same side of the pole post 30 in the thickness direction Z, and the third surface b3 and the fourth surface b4 are both located on the other side of the pole post 30 in the thickness direction Z. The second surface b2 extends beyond the first surface b1 of the first connecting portion 31 in the thickness direction Z of the pole post 30, and the third surface b3 extends beyond the fourth surface b4 of the second connecting portion 32 in the thickness direction of the pole post 30. In other words, on the side of the pole post 30 away from the cover plate 10, the first connecting portion 31 extends beyond each of the second connecting portions 32; on the side of the pole post 30 facing the cover plate 10, each of the second connecting portions 32 extends beyond the first connecting portion 31, so that the pole post 30 forms a structure in which each of the second connecting portions 32 is recessed relative to the first connecting portion 31 towards the cover plate 10. This allows the pole post 30 to be manufactured using a stamping process, that is, stamping processes such as upsetting and deep drawing are used to stamp the sheet metal, thereby forming the first connecting portion 31 and each of the second connecting portions 32 recessed relative to the first connecting portion 31 on the sheet metal. Compared with the cutting process that removes material in related technologies, this greatly reduces process costs and material costs.

[0129] In this embodiment, the first connecting portion 31 and each of the second connecting portions 32 of the pole post 30 are integrally formed, for example, by stamping. That is, the first connecting portion 31 and each of the second connecting portions 32 of the pole post 30 are integrally formed by stamping. Thus, compared with the cutting process that removes material in related technologies, using a stamping process to form the pole post 30 is more adaptable to mass production, improving production efficiency and reducing processing costs; on the other hand, it greatly reduces material waste in the pole post 30, lowering its material cost. It should be noted that in other embodiments, other integral forming processes can also be used, such as die casting or 3D printing, etc., and are not specifically limited here.

[0130] In the embodiments of this application, during the stamping process of forming the pole post 30, the corresponding area of ​​forming the second connecting portion 32 on the sheet metal includes a first region 321 and a second region 322 surrounding the first region 321. The second region 322 of the second connecting portion 32 is connected to the first connecting portion 31. The first region 321 of the second connecting portion 32 is drawn once or multiple times using a deep drawing process, so that the first region 321 of the second connecting portion 32 protrudes relative to the second region 322 along the thickness direction Z of the pole post 30 to form a connecting sub-portion 324. The surface of the second region 322 facing away from the cover plate 10 in the thickness direction Z of the pole post 30 is the aforementioned fourth surface b4. The second region 322 has a fifth surface b5 facing away from the aforementioned fourth surface b4; that is, the surface of the second region 322 facing away from the cover plate 10 is the fourth surface b4, and the surface of the second region 322 facing the cover plate 10 is the fifth surface b5. The distance between the fourth surface b4 and the fifth surface b5 is the thickness dimension of the second region 322. The second surface b2 is the side of the connecting part 324 facing away from the second region 322 in the thickness direction Z of the pole post 30. The pole lug 302 is welded and fixed to the second surface b2 of the connecting part 324. In this way, the first region 321 of the second connecting part 32 can be stretched once or multiple times by a stamping process, so that the first region 321 protrudes towards the cover plate 10 relative to the second region 322 to form the connecting part 324. The connecting part 324 passes through the first through hole 11 on the cover plate 10 and is then welded and fixed to the corresponding pole lug 302.

[0131] It should be noted that the tab 302 can be welded to the second surface b2 of the connector 324 using welding processes, such as laser welding, resistance welding, ultrasonic welding, and pressure welding. Alternatively, conductive adhesive can be used to bond and fix the tab 302 to the second surface b2 of the connector 324.

[0132] In this embodiment, the tab 302 is welded and fixed to the second surface b2 of the connector 324 by pressure welding. In this embodiment, a protrusion 34 is provided on the second surface b2 of the connector 324. During pressure welding, the tab 302 contacts the protrusion 34 on the second surface b2. Due to the small flow area at the protrusion 34, the heat generated is large, causing the protrusion 34 on the second surface b2 to melt and weld the tab 302 to the second surface b2.

[0133] In this embodiment, the pole post 30 further includes a transition portion 33, and each second connecting portion 32 is connected to the first connecting portion 31 through the transition portion 33. The end of the transition portion 33 connected to the second connecting portion 32 is the first end, which at least partially extends beyond the first surface b1 of the first connecting portion 31 along the thickness direction Z of the pole post 30. That is, the transition portion 33 extends obliquely relative to the thickness direction Z of the pole post 30 from the end connected to the first connecting portion 31 to the end connected to the second connecting portion 32, so that the fifth surface b5 of the second region 322 extends beyond the first surface b1 of the first connecting portion 31 in the thickness direction Z of the pole post 30. That is, the second region 322 of the second connecting portion 32 is lowered relative to the first connecting portion 31, thereby making the protrusion of the connecting sub-part 324 relative to the first connecting portion 31 greater. This is beneficial to reduce the drawing depth of the connecting sub-part 324, reduce the drawing difficulty, and improve the drawing quality of the pole post 30.

[0134] In this embodiment, the transition portion 33 is configured to melt first when the battery cell 1 experiences thermal runaway, meaning the transition portion 33 melts before the first connecting portion 31 and the second connecting portion 32. Specifically, in this embodiment, the flow area of ​​the transition portion 33 is smaller than the flow area of ​​the first connecting portion 31 and smaller than the flow area of ​​the second connecting portion 32. The flow area refers to the minimum area through which fluid passes. Here, the flow area of ​​the transition portion 33 refers to the surface area of ​​the transition portion 33 perpendicular to the current flow direction, i.e., the minimum cross-sectional area of ​​the transition portion 33. Similarly, the flow areas of the first connecting portion 31 and the second connecting portion 32 refer to the surface areas of the first connecting portion 31 and the second connecting portion 32 perpendicular to the current flow direction, i.e., the minimum cross-sectional areas of the first connecting portion 31 and the second connecting portion 32. Thus, in actual use, when a circuit malfunction occurs, the smaller flow area of ​​the transition portion 33 causes a faster temperature rise at the transition portion 33, allowing it to melt quickly and promptly disconnect the circuit, greatly improving battery safety. It is understandable that the transition portion 33 can reduce its current-carrying area by slotting, opening, and / or thinning, ensuring that it can melt and cut off the circuit in time when the circuit is abnormal. The thinning structure can be a general reduction in the thickness of the transition portion 33, or a groove structure formed in a part of the transition portion 33 and locally thinning the transition portion 33.

[0135] Please refer to Figures 4 to 8. In this embodiment, the connecting part 324 has a first groove 323. The opening of the first groove 323 passes through the end of the connecting part 324 opposite to the second surface b2, making the connecting part 324 have a hollow structure. This helps to reduce the weight of the pole post 30 and save the material of the pole post 30. It can be understood that during the process of drawing the sheet metal one or more times using a mold, the first region 321 of the sheet metal protrudes outward to one side relative to the second region 322, thereby forming the hollow connecting part 324.

[0136] In this embodiment, the depth D2 of the first groove 323 is 1mm to 5mm. If the depth of the first groove 323 is too shallow, the second surface b2 of the connector 324 will be far from the cell 301, requiring a longer tab 302; if the depth of the first groove 323 is too deep, the deep drawing process will be more difficult. In this embodiment, by rationally designing the depth of the first groove 323, a moderate depth is achieved. This allows for welding of the tab 302 to the second surface b2 of the connector 324 without needing to lengthen the tab 302, while also reducing the difficulty of the deep drawing process and improving production efficiency and the yield of the electrode post 30.

[0137] In this embodiment, the width F4 of the opening of the first groove 323 in the first preset direction X is 4mm to 25mm, and the width F5 of the bottom of the first groove 323 in the first preset direction X is 2mm to 20mm, with F5 < F4. Thus, designing the first groove 323 with a wide opening and a narrow bottom, and rationally designing the specific values ​​of the opening and bottom widths, facilitates optimization of material flow during deep drawing, improves deep drawing quality, and significantly reduces the risk of wrinkles at corners.

[0138] In this embodiment, the connecting part 324 has an annular sidewall 3245 and a bottom wall 3247. One end of the annular sidewall 3245 is connected to the second region 322. The bottom wall 3247 is connected to the other end of the annular sidewall 3245, and the surface of the bottom wall 3247 facing away from the annular sidewall 3245 is the aforementioned second surface b2. The annular sidewall 3245 and the bottom wall 3247 together form the aforementioned first groove 323. In the direction from the second region 322 to the bottom wall 3247, the outer contour dimension of the annular sidewall 3245 gradually decreases or decreases in a stepped manner, making the connecting part 324 have a shape that is larger at the top and smaller at the bottom. On the one hand, this is beneficial for deep drawing and reduces the processing difficulty; on the other hand, it makes it easier for the connecting part 324 to be inserted into the corresponding first through hole 11 on the cover plate 10 during assembly, reducing the assembly difficulty; and on the other hand, it makes the opening range of the first through hole 11 relatively small, thereby avoiding a significant decrease in the structural strength of the cover plate 10 due to the opening.

[0139] Referring to Figure 10, in this embodiment, the angle between the inner surface of the annular sidewall 3245 and a dummy axis C is α, which is parallel to the thickness direction of the pole post 30. The angle between the outer surface of the annular sidewall 3245 and the dummy axis C is β. Where α = β. α can be 5° to 60° and / or β can be 5° to 60°. Thus, by rationally designing the specific values ​​of angles α and β, the inclination of the annular sidewall 3245 is moderate, which facilitates improved material flow during deep drawing, enhances deep drawing quality, and significantly reduces the risk of wrinkles at corners. In other embodiments, α and β may also be unequal.

[0140] In this embodiment, the thickness of the first connecting portion 31 is T9, the thickness of the transition portion 33 is T13, the thickness of the second region 322 is T11, the thickness of the annular sidewall 3245 is T14, and the thickness of the bottom wall 3247 is T12, satisfying: T9 ≥ T12 ≥ T11 > T13 > T14. In this embodiment, T12 and T11 satisfy: T12 - T11 = 0 ~ 2 / 3 × T11. Thus, by rationally designing the thickness of each part of the pole post 30, the material flow during deep drawing can be further optimized, the deep drawing difficulty can be reduced, and production efficiency and yield can be improved.

[0141] In this embodiment, the first connecting portion 31 needs to be welded to the electrical connector, and the second connecting portion 32 needs to be welded to the tab 302 via the bottom wall 3247. Therefore, the thickness of the first connecting portion 31 and the bottom wall 3247 is thicker than other parts to provide sufficient weld penetration. The thickness T9 of the first connecting portion 31 is 2 mm to 8 mm, and the thickness T12 of the bottom wall 3247 is greater than or equal to 1.2 mm. Correspondingly, the thickness T14 of the annular sidewall 3245 of each connecting sub-part 324 is greater than or equal to 0.5 mm.

[0142] It should also be noted that the thickness of the second region 322 located on the side of the connecting sub-part 324 away from the first connecting part 31 may be equal to or unequal to the thickness of the side of the connecting sub-part 324 near the first connecting part 31, and this is not limited here. Similarly, the thickness of the annular sidewall 3245 located on the side of the first groove 323 away from the first connecting part 31 may be equal to or unequal to the thickness of the side of the first groove 323 near the first connecting part 31, and this is not limited here.

[0143] The positive terminal 30 is generally integrally formed from aluminum and can be directly contacted and welded to the positive electrode tab of the battery cell assembly 300. Since the positive terminal and the positive electrode tab of the battery cell assembly 300 are made of the same material, the welding effect between them can be improved.

[0144] Please refer to Figures 9 and 10. The electrode post 30, serving as the negative electrode, includes a first metal layer 326 and a second metal layer 327 stacked along the thickness direction Z of the electrode post 30. Both the first metal layer 326 and the second metal layer 327 extend to the first connecting portion 31, each transition portion 33, and each second connecting portion 32. The surface of the first metal layer 326 facing away from the second metal layer 327 includes the aforementioned third surface b3 and fourth surface b4. The surface of the second metal layer 327 facing away from the first metal layer 326 is a sixth surface, which includes the aforementioned first surface b1 and second surface b2. That is, the second metal layer 327 is located on the side of the first metal layer 326 facing the cell assembly 300, such that the second surface b2 is the second metal layer 327, i.e., the electrode tab 302 is welded to the second metal layer 327 at the second surface b2; the third surface b3 of the first connecting portion 31 is the first metal layer 326, i.e., the electrical connector is welded to the first metal layer 326 at the third surface b3.

[0145] Thus, by using a composite plate to prepare the electrode post 30, it is ensured that the tab 302 is welded to the second metal layer 327 at the connecting part 324. This second metal layer 327 can be made of the same material as the corresponding tab 302, or a material that is easily welded to the corresponding tab 302, ensuring the welding quality between the tab 302 and the second surface b2 of the connecting part 324. Similarly, by using a composite plate to prepare the electrode post 30, it is ensured that the electrical connector is welded to the first metal layer 326 at the first connecting part 31. This first metal layer 326 can be made of the same material as the electrical connector, or a material that is easily welded to the electrical connector, ensuring the welding quality between the electrical connector and the third surface b3 of the first connecting part 31. In this embodiment, the first metal layer is an aluminum layer, the second metal layer is a copper layer, and the electrode post 30 is made of a copper-aluminum composite plate through a stamping process. Since the negative electrode of the battery cell assembly is generally also made of copper, the second metal layer 327 is made of the same material as the negative electrode, which can improve the welding effect between the negative electrode post and the negative electrode.

[0146] In this embodiment, the thickness of the second metal layer 327 at the first connecting portion 31 is T2, the thickness of the second metal layer 327 at the second region 322 is T3, the thickness of the second metal layer 327 at the bottom wall 3247 is T5, the thickness of the second metal layer 327 at the annular sidewall 3245 is T7, and the thickness of the second metal layer 327 at the transition portion 33 is T8. Wherein, T2, T3, T5, T7, and T8 satisfy: T7 < T8 < T3 ≤ T5 ≤ T2. In this embodiment, T5, T3, and T2 satisfy: T5 - T3 = 0 ~ 0.5 × T2.

[0147] In this embodiment, the thickness T5 of the second metal layer 327 at the bottom wall 3247 is 0.3mm to 1.8mm. This ensures that the penetration depth when welding the tab 302 to the second surface b2 of the bottom wall 3247 is less than the thickness T5 of the second metal layer 327 at the bottom wall 3247, preventing the molten pool from entering the first metal layer 326 and causing welding defects such as spalls, thus further improving the welding quality.

[0148] In other embodiments, the thickness T5 of the second metal layer 327 at the bottom wall 3247 is 10% to 40% of the thickness T12 of the bottom wall 3247. This ensures that the penetration depth when welding the tab 302 to the second surface b2 of the bottom wall 3247 is less than the thickness T5 of the second metal layer 327 at the bottom wall 3247, preventing the molten pool from entering the first metal layer 326 and causing welding defects such as spalls, thus further improving the welding quality.

[0149] In this embodiment, the thickness T3 of the second metal layer 327 at the second region 322 is 0.05mm to 1.5mm.

[0150] In other embodiments, the thickness T3 of the second metal layer 327 at the second region 322 accounts for 10% to 40% of the thickness T11 of the second region 322.

[0151] In this embodiment, a second interface E is formed between the first metal layer 326 and the second metal layer 327 in the second region 322. In the thickness direction Z of the pole post 30, this second interface E extends beyond the first surface b1 of the first connecting portion 31, thereby ensuring that the second connecting portion 32 sinks sufficiently relative to the first connecting portion 31, thus minimizing the drawing depth of the connecting sub-portion 324, reducing the drawing difficulty, and improving the drawing quality.

[0152] In this embodiment, the height difference h between the second interface E and the first surface b1 in the thickness direction of the pole post 30 is 0.02mm to 1mm, and this height difference can be 0.1mm to 0.5mm. It should be noted that the height difference h is negatively correlated with the thickness of the cover plate 10 located in the second region 322; that is, the larger the height difference h, the thinner the cover plate 10 is located in the second region 322; the smaller the height difference h, the thicker the cover plate 10 is located in the second region 322. In this embodiment, the height difference h is designed to be within a suitable range, that is, the distance by which the second connecting part 32 sinks relative to the first connecting part 31 is limited to a suitable range, which can prevent the part of the cover plate 10 corresponding to the second region 322 from being too thin and thus deformed under pressure.

[0153] It should also be noted that the second metal layer 327 is not limited to extending to each of the second connecting portions 32, each of the transition portions 33, and the first connecting portion 31. In some other embodiments, as shown in Figures 7 and 8, the second metal layer 327 is only present at each of the second connecting portions 32, while only the first metal layer 326 is present at each of the transition portions 33 and the first connecting portion 31, and no second metal layer 327 is present. That is, the pole post 30 has only the first metal layer 326 at the first connecting portion 31 and each of the transition portions 33, and the pole post 30 has both the first metal layer 326 and the second metal layer 327 at each of the second connecting portions 32. In other words, the second connecting portion 32 is still a double-layer structure, and since the transition portion 33 and the first connecting portion 31 do not need to be welded to the negative electrode tab, the whole structure is made of aluminum, that is, the copper position in the first connecting portion 31 of the previous embodiment is replaced with aluminum. Thus, on the one hand, since the material of the first connecting part 31 is the same as that of the electrical connector, such as aluminum, it can improve the welding quality between the electrical connector and the third surface b3 of the first connecting part 31, as well as the welding quality between the electrode tab 302 and the second surface b2 of the second connecting part 32. On the other hand, it also greatly reduces the area of ​​the interface formed between the first metal layer 326 and the second metal layer 327. Since the bonding force at the interface between the first metal layer 326 and the second metal layer 327 is relatively large, it has an adverse effect on stamping. Therefore, reducing the interface area can greatly reduce the adverse effect of the interface on stamping, which is conducive to reducing the stamping difficulty and improving the stamping quality. On the other hand, since the first metal layer 326 is made of aluminum and the second metal layer 327 is made of copper, the amount of copper used can be saved to reduce costs while ensuring the structural strength of the pole 30. In other embodiments, the copper position in the first connecting part 31 of the previous embodiment can also be omitted, thereby reducing the overall thickness of the pole 30 to a certain extent.

[0154] In other embodiments, the second metal layer 327 is only present at each of the second connection portions 32, including at least the following situations: (1) The second metal layer 327 is located on the bottom wall 3247. The area of ​​the second metal layer 327 on the bottom wall 3247 can be adjusted according to the welding area of ​​the negative electrode tab and the bottom wall 3247. That is, the side of the bottom wall 3247 facing the inside of the battery cell can be entirely composed of the second metal layer 327 or partially composed of the second metal layer 327, as long as the welding effect of the negative electrode tab and the bottom wall 3247 can be guaranteed; (2) The second metal layer 327 is located on the bottom wall 3247 and extends to the annular sidewall 3245; (3) The second metal layer 327 is located on the bottom wall 3247 and extends to the annular sidewall 3245 and the second region 322.

[0155] In this embodiment, the transition portion 33 has a seventh surface b7, which is located on the same side of the pole post 30 in the thickness direction Z as the sixth surface b6. That is, the surface of the transition portion 33 facing the cover plate 10 is the seventh surface b7. The seventh surface b7 and the sixth surface b6 are transitioned by an arc-shaped segment 332. Referring to Figure 8, the second metal layer 327 has a first interface D at one end near the first connecting portion 31. There is a preset distance L between the first interface D and the arc-shaped segment 332. In this way, the preset distance L is reserved between the first interface D and the arc-shaped segment 332 at the corner, which avoids the first interface D of the second metal layer 327 from extending to the corner and causing adverse effects on the material flow during stamping, which helps to reduce the stamping difficulty and improve the stamping quality.

[0156] In this embodiment, the preset distance L satisfies: 0.5mm ≤ L ≤ 6mm. This design keeps the preset distance L within a suitable range, preventing it from becoming too large. This avoids wasting material on the pole 30 and also prevents the area at this point from becoming too large, thus encroaching on the area of ​​the first connecting portion 31 and the second connecting portion 32, which would otherwise result in the area of ​​the second surface b2 welded to the tab 302 and / or the third surface b3 welded to the electrical connector being too small.

[0157] It should be noted that, as one implementation, the electrical connector can be made of aluminum. To ensure the welding quality between the electrical connector and the third surface b3 of the first connecting portion 31, the first metal layer 326 can also be an aluminum layer. Similarly, the tab 302 can be made of copper. To ensure the welding quality between the tab 302 and the second surface b2 of the connecting portion 324, the second metal layer 327 can also be a copper layer.

[0158] It should also be noted that the electrode post 30 is not limited to being fabricated using composite materials, that is, the electrode post 30 is not limited to having a first metal layer 326 and a second metal layer 327. In some embodiments, the electrode post 30, as the positive electrode post, may only have a first metal layer 326 and not have a second metal layer 327. For example, when the material of the electrical connector is aluminum and the material of the tab 302 is also aluminum, the electrode post 30 may only have a first metal layer 326, which is an aluminum layer. Furthermore, in sodium-ion batteries, the materials of both the positive and negative tabs can be aluminum, and correspondingly, the materials of both the positive and negative electrode posts can also be aluminum. That is, in some battery types, both the positive and negative electrode posts may only have a first metal layer 326 and not have a second metal layer 327.

[0159] In one implementation, when the positive electrode tab is made of aluminum and the negative electrode tab is made of copper, the positive electrode post adopts a structure having only a first metal layer 326 (without a second metal layer 327), while the negative electrode post adopts a structure having a first metal layer 326 and a second metal layer 327.

[0160] Please refer to Figures 1, 2, and 7. In the embodiments of this application, the top cover assembly 100 further includes a first insulating member 20, at least a portion of which forms insulation between the cover plate 10 and the pole post 30. The first insulating member 20 can be injection molded with the pole post 30 first, and then assembled integrally with the cover plate 10; alternatively, the pole post 30 can be assembled onto the cover plate 10 first, and then the first insulating member 20 can be integrally injection molded.

[0161] In this embodiment, the first insulating member 20 includes a first insulator portion 21 and a second insulator portion 22. The first insulator portion 21 is disposed between the first connecting portion 31 and the cover plate 10 to form insulation, thereby preventing the cover plate 10 from becoming energized or short-circuited. The second insulator portion 22 covers each of the second connecting portions 32 and each of the transition portions 33, providing insulation protection for the surfaces of each of the second connecting portions 32 and each of the transition portions 33; secondly, increasing the creepage distance from the transition portion 33 to the third surface b3 of the pole post 30, thereby increasing the electrical clearance between the transition portion 33 and the electrical connector after welding the electrical connector; and thirdly, increasing the overall strength of the pole post 30, greatly reducing the risk of deformation of the pole post 30.

[0162] In this embodiment, at least one second through hole 330 is provided on the transition portion 33 (see FIG. 4). The first insulating member 20 also includes a third insulator portion 23 (see FIG. 12) filled in the second through hole 330. The third insulator portion 23 is connected to the first insulator portion 21 and the second insulator portion 22 to form the first insulating portion 230. The first insulator portion 21, the second insulator portion 22 and the third insulator portion 23 are integrally injection molded. Thus, during injection molding, molten injection molding material is injected into the surface of each second connecting portion 32. A portion of the injection molding material covers the surface of each second connecting portion 32 and each transition portion 33, and after solidification, forms the second insulator portion 22. Another portion of the injection molding material flows through the second through hole 330 into the space between the first connecting portion 31 and the cover plate 10, and after solidification, forms the third insulator portion 23 in the second through hole 330, and forms the first insulator portion 21 between the first connecting portion 31 and the cover plate 10. The third insulator portion 23, which fills the second through hole 330, can compensate for the structural strength loss of the transition portion 33 due to the formation of the second through hole 330, and prevent the structural strength of the pole post 30 from being too low. Moreover, it can also increase the contact area between the first insulator 20 and the pole post 30, thereby improving the bonding force between the two.

[0163] It should be noted that the second through hole 330 on the transition section 33 serves two purposes: firstly, it facilitates the flow of injection molding material during injection molding; secondly, it reduces the flow area of ​​the transition section 33, ensuring that the transition section 33 can melt and cut off the circuit in time in case of an abnormality.

[0164] In this embodiment, the top cover assembly 100 also includes a flange structure 12. The flange structure 12 is fixedly connected to the side surface of the cover plate 10 away from the cell assembly 300, and a portion of the flange structure 12 can be bent to the side surface of the second insulator portion 22 away from the cover plate 10 by a rolling process, thereby using the flange structure 12 to press the second insulator portion 22 and the second connecting portion 32 of the pole post 30 onto the cover plate 10, preventing the pole post 30 from detaching from the cover plate 10.

[0165] In this embodiment, the second insulator portion 22 has a first stepped surface 223 extending along its peripheral edge. The flange structure 12 extends along the peripheral edge of the second insulator portion 22 and presses against the first stepped surface 223, making the pressing structure of the flange structure 12 against the second insulator portion 22 more stable, thereby making the assembly structure of the pole post 30 and the cover plate 10 more stable and preventing the pole post 30 from shifting position or even detaching from the cover plate 10.

[0166] In this embodiment, a second groove 315 is formed on the first surface b1 of the first connecting portion 31, and a third groove 13 is formed on the surface of the cover plate 10 facing the first insulator portion 21. A portion of the first insulator portion 21 fills the second groove 315, and a portion of the first insulator portion 21 also fills the third groove 13. Thus, during injection molding of the first insulating part 20, the molten injection material can flow into the second groove 315 and the third groove 13, and after solidification, form a structure in which a portion of the first insulator portion 21 fills the second groove 315 and the third groove 13.

[0167] In this embodiment, at least a portion of the second groove 315 gradually narrows or tapers in a stepped manner from the bottom to the opening, thereby ensuring that the first insulator portion 21 is tightly nested on the pole post 30, preventing the pole post 30 from separating from the first insulating member 20. At least a portion of the third groove 13 gradually narrows or tapers in a stepped manner from the bottom to the opening, thereby ensuring that the first insulator portion 21 is tightly nested on the cover plate 10, preventing the cover plate 10 from separating from the first insulating member 20.

[0168] In this embodiment, the depth of the second groove 315 is H2, and the thickness of the first connecting portion 31 is T9. H2 and T9 satisfy: H2 = (5% ~ 50%)T9. Thus, by designing the depth of the second groove 315 within a suitable range, on the one hand, it avoids the second groove 315 being too shallow, resulting in an insignificant effect in increasing the bonding force between the first insulator portion 21 and the first connecting portion 31; on the other hand, it avoids the second groove 315 being too deep, resulting in lower strength of the first connecting portion 31 and susceptibility to deformation.

[0169] In this embodiment, the depth of the third groove 13 is H3, and the thickness of the cover plate 10 is H4, where H3 and H4 satisfy: H3 = (5% ~ 50%)H4. Thus, by designing the depth of the third groove 13 within a suitable range, it avoids both situations where the third groove 13 is too shallow, resulting in an insignificant increase in the bonding force between the first insulator portion 21 and the cover plate 10, and where the third groove 13 is too deep, leading to weak strength of the cover plate 10 and easy deformation. In this embodiment, the second insulator portion 22 is recessed into the first groove 323 to form a fourth groove 225. That is, the second insulator portion 22 covers the inner wall of the first groove 323 but does not fill the entire first groove 323. This is beneficial in improving the bonding force between the second insulator portion 22 and the second connecting portion 32 of the pole post 30, preventing separation or misalignment of the second insulator portion 22 and the second connecting portion 32; it also reduces the material usage of the second insulator portion 22 and avoids uneven injection molding defects caused by excessive local thickness.

[0170] In this embodiment, the first connecting portion 31 has a boss 311 and an annular surface 312 on the side opposite to the first surface b1. The annular surface 312 is arranged around the boss 311, and the boss 311 protrudes relative to the annular surface 312 in a direction away from the first surface b1. The electrical connector is welded to the boss 311, and the second insulator portion 22 of the first insulating member 20 is lower than or flush with the annular surface 312. Thus, by providing the boss 311, the flow of injection molding material can be prevented from flowing onto the boss 311 during injection molding, causing the first insulating member 20 to cover the surface of the boss 311.

[0171] In this embodiment, the protrusion height H1 of the boss 311 relative to the annular surface 312 is 0.05mm to 0.8mm, and H1 can be within multiple ranges such as 0.1mm to 0.6mm or 0.3mm to 0.5mm. It should be noted that H1 can be 0.05mm, 0.20mm, 0.35mm, 0.50mm, 0.65mm or 0.8mm, etc., and is not specifically limited here.

[0172] In this embodiment, the top cover assembly 100 further includes a sealing ring 40, which includes a first sealing portion 41 and a second sealing portion 43. Both the first sealing portion 41 and the second sealing portion 43 are sleeved on the connecting portion 324. The first sealing portion 41 is located between the inner wall of the first through hole 11 and the connecting portion 324, and the second sealing portion 43 is located between the surface of the cover plate 10 facing away from the cell assembly 300 and the second region 322. Thus, on the one hand, the sealing ring 40 seals the first through hole 11 on the cover plate 10, preventing electrolyte leakage from the housing 200 through the first through hole 11; on the other hand, the sealing ring 40 forms insulation between the connecting portion 324, the second region 322, and the cover plate 10, preventing electrical conduction between the electrode post 30 and the cover plate 10.

[0173] In this embodiment, referring to Figure 5, the second region 322 includes a first straight section a1, a first arc section a2, a second straight section a3, and a second arc section a4 connected end to end. The first straight section a1 and the second straight section a3 are located on both sides of the first region 321 in the first preset direction X, and the first arc section a2 and the second arc section a4 are located on both sides of the first region 321 in the second preset direction Y. The radius of curvature R of the outer edge of the first arc section a2 and the outer edge of the second arc section a4 is 3mm to 8mm. R can be in multiple ranges such as 4mm to 6mm, 3mm to 5mm, and 5mm to 8mm, and can be selected according to the actual situation. In this way, by setting the radius of curvature R of the outer edge of the first arc section a2 and the outer edge of the second arc section a4 within a suitable range, on the one hand, it avoids that R is too small, which would prevent the flange structure 12 from being unable to fold onto the second insulator section 22; on the other hand, it avoids that R is too large, which would result in an excessively large arc area of ​​the second region 322, thereby avoiding waste of the pole post 30 material.

[0174] In this embodiment, on a dummy plane perpendicular to the thickness direction of the pole post 30, the orthographic projection of the first connecting portion 31 does not overlap with the orthographic projection of each of the second connecting portions 32. That is, each of the second connecting portions 32 and the first connecting portion 31 are completely staggered in the thickness direction Z of the pole post 30, so that the welding position of the first connecting portion 31 to the electrical connector is far enough away from each of the second connecting portions 32. Therefore, when the electrical connector is welded to the third surface b3 of the first connecting portion 31, the adverse effects of the heat generated by welding on the first insulating component 20 and the sealing ring 40 are greatly reduced, which helps to reduce the risk of cracking or heat melting of the first insulating component 20 and improve the sealing reliability of the sealing ring 40.

[0175] It should also be noted that the top cover assembly 100 can be assembled by pre-injection molding or integral injection molding. Please refer to Figures 11 and 12. Pre-injection molding means: first, the pole post 30 is formed by stamping; then, the first insulating part 20 is injection molded on the pole post 30, so that the pole post 30 and the first insulating part 20 form an integral whole; then, the sealing ring 40 is sleeved on the connecting part 324 of the pole post 30, and the connecting part 324 of the pole post 30 is inserted into the first through hole 11 on the cover plate 10; then, the flange structure 12 is rolled so that part of the flange structure 12 is bent onto the second insulating part 22 of the first insulating part 20, thereby pressing the pole post 30 and the first insulating part 20 onto the cover plate 10, while compressing the sealing ring 40 so that the sealing ring 40 seals the first through hole 11.

[0176] In the pre-injection molding method, since the flange structure 12 is rolled to the folded state after the first insulating part 20 is injection molded, the second insulator part 22 of the injection molded first insulating part 20 does not cover the flange structure 12.

[0177] Please refer to Figures 7 and 9. The integral injection molding method refers to the following steps: First, the pole post 30 is formed using a stamping process; then, the sealing ring 40 is fitted onto the connecting part 324 of the pole post 30, and the connecting part 324 is inserted into the first through hole 11 on the cover plate 10; then, the pole post 30, the sealing ring 40, and the cover plate 10 are installed as a whole into the injection mold for injection molding, thereby injection molding the first insulating part 20 (the flange structure 12 has been rolled during the injection molding of the first insulating part 20). During the injection molding of the first insulating part 20, pressure is applied to the pole post 30, so that the pole post 30 compresses the sealing ring 40, so that the sealing ring 40 maintains a certain amount of compression; after the injection molding is completed, the cover plate 10, the sealing ring 40, the pole post 30, and the first insulating part 20 are removed from the injection mold as a whole. At this time, the pressure on the pole post 30 disappears, but due to the pressing action of the flange structure 12 on the first insulating element 20, the pole post 30 and the first insulating element 20 can remain pressed tightly on the cover plate 10, and the sealing ring 40 can also remain in a compressed state.

[0178] In the one-piece injection molding method, since the flange structure 12 has been rolled to a folded state before the first insulating part 20 is injection molded, the second insulator part 22 of the injection molded first insulating part 20 also covers the flange structure 12.

[0179] Considering that the sealing ring 40 on the side of the connecting sub-part 324 opposite to the first connecting part 31 indirectly bears the pressure from the flange structure 12, while the pressure on the side of the sealing ring 40 closer to the first connecting part 31 is relatively small, this portion will push upwards against the second region 322 on the side of the connecting sub-part 324 closer to the first connecting part 31. Therefore, the thickness of the second region 322 on the side of the connecting sub-part 324 closer to the first connecting part 31 is configured to be greater than the thickness of the second region 322 on the side of the connecting sub-part 324 opposite to the first connecting part 31. This increases the thickness of the second region 322 on the side of the connecting sub-part 324 closer to the first connecting part 31, thereby increasing the structural strength of this portion.

[0180] The pole post 30 can also be mounted on the housing 200. The structure of the pole post 30 mounted on the housing 200 is similar to that mounted on the cover plate 10, so it will not be described in detail here.

[0181] This application also provides another battery cell 1. Referring to Figures 13, 14, 15, and 16, the battery cell 1 includes a housing 200, a cell assembly 300, a top cover assembly 100, and other functional components. At least one end of the housing 200 has an opening, and the top cover assembly 100 covers the opening of the housing 200 to isolate the internal environment of the battery cell 1 from the external environment. The housing 200 has a receiving cavity inside to accommodate the cell assembly 300 within the receiving cavity. The housing 200 is a component used to cooperate with the top cover assembly 100 to form the internal environment of the battery cell 1, wherein the formed internal environment can accommodate the cell assembly 300, electrolyte, and other components. The housing 200 and the top cover assembly 100 can be independent components. An opening can be provided on the housing 200, and the top cover assembly 100 closes the opening to form the internal environment of the battery cell 1. The housing 200 can be of various shapes and sizes, such as cylindrical, cuboid, hexagonal prism, etc. In this embodiment, the shape of the housing 200 can be determined according to the specific shape and size of the battery cell assembly 300. The material of the housing 200 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment does not impose any special limitations on this.

[0182] As one embodiment of the top cover assembly 100, referring to Figures 15 to 20, the top cover assembly 100 includes a cover plate 10, which covers the opening of the housing 200. In any case, the shape of the cover plate 10 can be adapted to the shape of the housing 200 to fit the opening of the housing 200. The cover plate 10 can be made of a material with a certain hardness and strength (such as aluminum alloy or aluminum), so that the cover plate 10 is not easily deformed under pressure and impact, enabling the battery cell 1 to have higher structural strength and improved safety performance. The material of the cover plate 10 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this.

[0183] Referring to Figure 20, the cover plate 10 has a first through hole 11 extending through its thickness direction. The first through hole 11 is used to install functional components, such as pole posts 30. In this embodiment, the surface of the cover plate 10 facing the outside of the housing is provided with a fifth groove 14, which is recessed from the surface of the cover plate 10 facing the outside of the housing towards the surface of the cover plate 10 facing the inside of the housing. The first through hole 11 penetrates the bottom wall of the groove of the fifth groove 14 along the thickness direction of the cover plate 10. For example, in this embodiment, two first through holes 11 are provided in the fifth groove 14, with a gap between the hole wall of the first through hole 11 and the groove side wall of the fifth groove 14, that is, the hole wall of the first through hole 11 and the groove side wall of the fifth groove 14 are not aligned. When the terminal post 30 is installed on the cover plate 10, the fifth groove 14 reduces the distance between the first electrical connection surface 3122 of the terminal post 30 facing the outside of the housing and the upper surface of the cover plate 10, thereby improving the space utilization of the battery. At the same time, the fifth groove 14 allows the second connection portion 32 of the terminal post 30 to be closer to the inside of the housing, which can reduce the height of the second connection portion 32, thereby reducing the height of the terminal post 30 and reducing the processing difficulty of the terminal post 30.

[0184] As shown in Figure 20, the cover plate 10 may be provided with functional components such as pole post 30, first insulating element 20, second insulating element 50, and pressure relief mechanism 7. The cover plate 10 and the functional components such as pole post 30, first insulating element 20, second insulating element 50 and pressure relief mechanism 7 provided on the cover plate 10 together constitute the top cover assembly 100.

[0185] In this embodiment, referring to Figures 18, 19, and 20, the electrode post 30 includes at least one first connecting portion 31 and at least two second connecting portions 32. The first connecting portion 31 is used to connect with an electrical connector, and the second connecting portions 32 are used to connect with the tabs 302 of the battery cell assembly 300. The first connecting portion 31 is disposed on the side of the cover plate 10 facing the outside of the housing so that the first connecting portion 31 can connect with the electrical connector. At least a portion of the second connecting portion 32 passes through the first through hole 11 of the cover plate 10 so that the second connecting portion 32 can connect with the tabs 302. Each first connecting portion 31 is disposed between two adjacent second connecting portions 32 and is connected to two adjacent second connecting portions 32. At least two second connecting portions 32 are arranged at intervals along a first preset direction X, that is, at least two second connecting portions 32 are arranged at intervals along the width direction of the electrode post 30.

[0186] The second connecting part 32 in this embodiment can be directly welded to the tab 302. Therefore, at least a portion of the second connecting part 32 passes through the first through hole 11 and extends into the housing 200 to be directly connected to the tab 302. No adapter structure is required, which reduces the use of parts, lowers the cost of the battery cell 1, and at the same time reduces the internal resistance of the battery cell 1 and increases the energy density of the battery cell 1.

[0187] The cover plate 10 may have a first through hole 11 corresponding to each second connecting part 32, so that each second connecting part 32 passes through the first through hole 11 and is connected to the corresponding tab 302. It is understood that the number of first through holes 11 may be the same as the number of second connecting parts 32. In other embodiments, the size of the first through hole 11 may also allow two second connecting parts 32 to pass through.

[0188] In this embodiment, as shown in Figure 23 or Figure 32, the maximum width of the electrode post 30 along the first preset direction X is W2, satisfying: 14mm ≤ W2 ≤ 80mm. For example, W2 can be located within multiple intervals such as 14mm ≤ W2 ≤ 60mm, 14mm ≤ W2 ≤ 40mm, 14mm ≤ W2 ≤ 30mm, 20mm ≤ W2 ≤ 30mm, etc. In this embodiment, W2 = 14mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, 65mm, 70mm, 75mm, or 80mm, or any value between the two. Through the above settings, the width of the electrode post 30 can ensure that the first connecting portion 31 and the two second connecting portions 32 have a welding area that meets the requirements, and it can be applied to battery cells 1 of various thicknesses.

[0189] As one embodiment of the pole post 30, please refer to Figures 21, 22, 26, 27, 30, 31, 35, and 36. The first connecting portion 31 of the pole post 30 includes a base portion 3110 and a first electrical connection portion 3120, which are integrally formed. Along a third preset direction Z (i.e., the thickness direction of the pole post 30), the base portion 3110 has a first surface 3111 and a third surface 3112 opposite to the first surface 3111. The third surface 3112 is the first surface b1 of the first connecting portion 31. The first surface 3111 can be the surface of the base portion 3110 facing the outside of the housing, and the third surface 3112 can be the surface of the base portion 3110 facing the inside of the housing. The first electrical connection portion 3120 is disposed on the surface of the base portion 3110 having the first surface 3111. It is understood that the first electrical connection portion 3120 and the base portion 3110 are stacked along the thickness direction of the pole post 30, and the cross-sectional area of ​​the base portion 3110 is larger than the cross-sectional area of ​​the first electrical connection portion 3120. The first electrical connection portion 3120 is used to connect with an electrical connector. The base portion 3110 can be connected with the second connection portion 32.

[0190] As shown in Figure 23 or Figure 32, along the first preset direction X, the relationship between the maximum width W1 of the first electrical connection portion 3120 and the maximum width W2 of the pole post 30 satisfies: 20% ≤ W1 / W2 ≤ 60%. For example, W1 / W2 can be located in multiple intervals such as 30% ≤ W1 / W2 ≤ 50%, 35% ≤ W1 / W2 ≤ 45%, etc. In this embodiment, W1 / W2 = 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, or 50%, or any value between any two of the above. Through the above settings, the welding surface width of the first electrical connection portion 3120 and the welding surface width of the second connection portion 32 can both meet the overcurrent requirements. When W1 / W2 is less than 20%, the width of the first electrical connection 3120 is small, resulting in a small welding area and causing the welding point of the first electrical connection 3120 to become a current bottleneck. When W1 / W2 is greater than 60%, the width of the first electrical connection 3120 is large, resulting in a small welding surface width of the second connection 32 and causing the welding point of the second connection 32 to become a current bottleneck.

[0191] Furthermore, as shown in Figure 23 or Figure 32, along the first preset direction X, the maximum width of the first electrical connection portion 3120 is W1, satisfying: 8mm ≤ W1 ≤ 35mm. For example, W1 can be located within multiple intervals such as 8mm ≤ W1 ≤ 25mm and 8mm ≤ W1 ≤ 15mm. In this embodiment, W1 = 8mm, 10mm, 15mm, 20mm, 25mm, 30mm, or 35mm, or any value between any two of the above. Through the above settings, the first electrical connection portion 3120 can have a welding surface width that meets the requirements.

[0192] As shown in Figure 24, 28, or 33, along the second preset direction Y, the relationship between the maximum length W11 of the first electrical connection portion 3120 and the maximum length W10 of the base portion 3110 of the first connection portion 31 satisfies: 85% ≤ W11 / W10 ≤ 98%. For example, W11 / W10 can be located in multiple intervals such as 85% ≤ W11 / W10 ≤ 95% and 85% ≤ W11 / W10 ≤ 90%. In this embodiment, W11 / W10 = 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, or 98%, or any value between any two of the above. With the above settings, the lengths of the first electrical connection portion 3120 and the base portion 3110 are set within a suitable range, which makes it easier for the upper and lower dies and the edges of the base portion 3110 to have sufficient contact area when the pole post 30 is punched out of the outer contour, thereby reducing the processing difficulty of the pole post 30 and reducing the burrs generated on the outer edge of the pole post 30; at the same time, it provides a suitable width for the first insulating member 20 covering the circumference of the first electrical connection portion 3120, and avoids the first insulating member 20 from falling off from the pole post 30 due to insufficient covering width.

[0193] Furthermore, as shown in Figure 24, 28, or 33, along the second preset direction Y, the maximum length of the base portion 3110 of the first connecting portion 31 is W10, satisfying: 15mm ≤ W10 ≤ 50mm; for example, W10 can be located within multiple intervals such as 15mm ≤ W10 ≤ 40mm, 15mm ≤ W10 ≤ 35mm, 15mm ≤ W10 ≤ 30mm, 15mm ≤ W10 ≤ 25mm, etc. In this embodiment, W10 = 15mm, 18mm, 20mm, 25mm, 28mm, 30mm, 32mm, 35mm, 37mm, 40mm, 43mm, 45mm, 47mm, or 50mm, or any value between any two of the above. Through the above settings, the first connecting portion 31 can have a welding area that meets the requirements, while also preventing the length of the welding area from being too large. When W10 is less than 15mm, the welding area of ​​the first connection part 31 will be shorter, resulting in a smaller current flow area and a lower charge / discharge rate of the battery cell 1. When W10 is greater than 50mm, the welding area of ​​the first connection part 31 will be too long, increasing the cost and weight of the terminal post.

[0194] Along the second preset direction Y, as shown in Figures 24, 28, 31, or 36, the minimum distance between the edge side of the first electrical connection portion 3120 and the edge side of the base portion 3110 is 'a', satisfying: 0.2mm ≤ a ≤ 5mm. For example, a = 0.2mm, 0.3mm, 0.4mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2.0mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm, 3.0mm, 3.2mm, 3.4mm, 3.6mm, 3.8mm, 4mm, 4.2mm, 4.4mm, 4.6mm, 4.8mm, or 5mm, or any value between any two of the above. 'a' can also be located within the range of 0.3mm ≤ a ≤ 4mm, for example, a = 0.3mm, 0.4mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2.0mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm, 3.0mm, 3.2mm, 3.4mm, 3.6mm, 3.8mm, or 4mm, or any value between any two of the above. 'a' can also be located within the range of 1.2mm ≤ a ≤ 3mm, for example, a = 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2.0mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm, or 3.0mm, or any value between any two of the above. 'a' can also be within the range of 1.5mm ≤ a ≤ 2.5mm, for example, a = 1.5mm, 1.6mm, 1.8mm, 2.0mm, 2.2mm, 2.4mm, or 2.5mm, or any value between any two of the above. 'a' can also be within the range of 1.8mm ≤ a ≤ 2.2mm, for example, a = 1.8mm, 1.9mm, 2.0mm, 2.1mm, or 2.2mm, or any value between any two of the above. This configuration facilitates the punching of the outer contours of the base portion 3110 and the first electrical connection portion 3120. When 'a' is less than 0.2mm, the edge of the first electrical connection portion 3120 is closer to the edge of the base portion 3110, causing the second step surface 3121 to collapse. When 'a' is greater than 5mm, the welding area of ​​the first electrical connection surface 3122 decreases, affecting the current carrying capacity of the electrode.

[0195] Referring to Figures 21 and 22, or 26 and 27, or 30 and 31, or 35 and 36, the first electrical connection portion 3120 includes a first sub-portion 3123 and a second sub-portion 3124. Along a third preset direction Z, one end of the first sub-portion 3123 is connected to the base portion 3110, and the opposite end is connected to the second sub-portion 3124. It is understood that the second sub-portion 3124 and the first sub-portion 3123 are stacked along the third preset direction Z. Along the third preset direction Z, the orthographic projection of the second sub-portion 3124 onto the cover plate 10 falls within the orthographic projection range of the first sub-portion 3123 onto the cover plate 10; that is, the cross-sectional area of ​​the second sub-portion 3124 is smaller than the cross-sectional area of ​​the first sub-portion 3123. In some embodiments, the upper or lower surface of the cover plate 10 is a plane perpendicular to the third preset direction Z. A second stepped surface 3121 is thus connected between the sidewalls of the first sub-part 3123 and the second sub-part 3124. The second stepped surface 3121 is the annular surface 312 in the above embodiment, and the second sub-part 3124 is the boss 311 in the above embodiment. The end surface of the second sub-part 3124 away from the first sub-part 3123 is the first electrical connection surface 3122, which is a welding surface for welding with an electrical connector. The weld penetration depth between the electrical connector and the first electrical connection surface 3122 can extend from the first electrical connection surface 3122 into the interior of the first electrical connection portion 3120. Both the second stepped surface 3121 and the first electrical connection surface 3122 are located on the side of the first electrical connection portion 3120 away from the first surface 3111. The first electrical connection surface 3122 extends beyond the second stepped surface 3121 along a third preset direction Z. That is, the second stepped surface 3121 is located closer to the base portion 3110 than the first electrical connection surface 3122, and the second stepped surface 3121 surrounds the edge of the first electrical connection portion 3120. The arrangement of the second stepped surface 3121 ensures that there is a distance between the edge of the first insulating member 20 covering the outside of the base portion 3110 and the first electrical connection surface 3122, preventing interference with the first electrical connection surface 3122 and thus affecting the welding quality between the first electrical connection surface 3122 and the electrical connector. Understandably, during injection molding of the first insulating member 20, the arrangement of the second stepped surface 3121 prevents plastic material from overflowing onto the first electrical connection surface 3122 and affecting the welding quality.

[0196] Since the second step surface 3121 is formed around the side wall of the second sub-part 3124, in some embodiments, the second step surface 3121 is located on a plane perpendicular to the third preset direction Z. Thus, as shown in FIG23 or FIG32, on the plane perpendicular to the third preset direction Z, that is, on the plane composed of the first preset direction X and the second preset direction Y, including both the first preset direction X and the second preset direction Y, the width of the second step surface 3121 is W3, which satisfies: 0.3mm≤W3≤1mm. For example, W3 can be located in multiple intervals such as 0.3mm≤W3≤0.8mm, 0.3mm≤W3≤0.5mm, etc. In this embodiment, W3 = 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1mm or any value between any two of the above. Since the positioning tolerance of the pole post 30 is approximately 0.15mm, setting the width W3 of the second step surface 3121 within the aforementioned range provides a certain pressing surface for the welding fixture, enabling welding between the first electrical connection surface 3122 and the electrical connector, while ensuring that the first electrical connection surface 3122 has sufficient welding area. It also provides sufficient connection surface width for the first insulating member 20 to be pressed onto the first surface 3111 of the base portion 3110, allowing the first insulating member 20 to be stably connected to the first connecting portion 31. Of course, in some other embodiments, the second step surface 3121 may also have an angle with the plane perpendicular to the third preset direction Z, i.e., the second step surface 3121 is inclined. In this case, the width W3 of the second step surface 3121 on the plane perpendicular to the third preset direction Z is the width of the orthographic projection of the second step surface 3121 on the plane perpendicular to the third preset direction Z.

[0197] As shown in Figure 23 or Figure 32, along the third preset direction Z, the distance between the second step surface 3121 and the first electrical connection surface 3122 is W4, satisfying: 0.2mm≤W4≤0.7mm. For example, W4 can be located in the range of 0.2mm≤W4≤0.5mm. In this embodiment, W4 = 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm or 0.7mm, or any value between any two of the above. Setting the distance W4 between the second step surface 3121 and the first electrical connection surface 3122 within the above range makes it less likely that the height of the electrode post 30 will be too high, thereby improving the space utilization of the battery and reducing the molding difficulty of the electrode post 30. It also prevents W4 from being too small, so as to avoid the plastic material overflowing onto the first electrical connection surface 3122 and affecting the welding quality.

[0198] The relationship between the width W3 of the second step surface 3121 and the maximum width W1 of the first electrical connection portion 3120 satisfies: 1% ≤ W3 / W1 ≤ 10%. For example, W3 / W1 can be located in multiple intervals such as 1% ≤ W3 / W1 ≤ 8%, 1% ≤ W3 / W1 ≤ 5%, etc. In this embodiment, W3 / W1 = 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%, or any value between any two of the above. Through the above settings, a certain pressing surface can be provided for the welding fixture to realize the welding between the first electrical connection surface 3122 and the electrical connector, while ensuring that the first electrical connection surface 3122 has sufficient welding area. Understandably, when the first electrical connection portion 3120 does not have the second stepped surface 3121, the maximum width W1 of the first electrical connection portion 3120 is equal to the maximum width of the first electrical connection surface 3122, that is, the entire surface of the first electrical connection portion 3120 away from the base portion 3110 serves as the first electrical connection surface 3122. In some embodiments, although the cross-sectional area of ​​the base portion 3110 is larger than the cross-sectional area of ​​the first electrical connection portion 3120, the maximum width of the base portion 3110 in the first preset direction X can be equal to the maximum width W1 of the first electrical connection portion 3120.

[0199] As shown in Figure 23 or Figure 32, along the third preset direction Z, the distance between the second step surface 3121 and the first electrical connection surface 3122 is W4, and the distance between the first electrical connection surface 3122 and the first surface 3111 is W6, satisfying: 15% ≤ W4 / W6 ≤ 50%. For example, W4 / W6 can be located at 15% ≤ W4 / W6 ≤ 40%, 15% ≤ W4 / W6 ≤ 30%, 15% ≤ W4 / W6 ≤ 25%, or 15% ≤ W4 / W6. Within multiple ranges such as ≤20%, in this embodiment, W4 / W6 = 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%, or any value between any two of the above. Through the above settings, the height of the electrode post 30 is not too high, reducing the molding difficulty of the electrode post 30 and improving the space utilization of the battery. At the same time, W4 is not too small to avoid the plastic material overflowing onto the first electrical connection surface 3122 and affecting the welding quality.

[0200] As shown in Figure 23 or Figure 32, along the third preset direction Z, the distance between the first electrical connection surface 3122 and the first surface 3111 of the first electrical connection portion 3120 is W6, satisfying: 0.7mm≤W6≤2mm. For example, W6 can be located in multiple intervals such as 0.7mm≤W6≤1.5mm, 0.7mm≤W6≤1.2mm, etc. In this embodiment, W6 = 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, or 2.0mm, or any value between any two of the above. The above settings ensure that the thickness of the first insulating member 20 covering the first electrical connection portion 3120 in the circumferential direction is neither too thin nor too thick. When W6 is less than 0.7mm, the thickness of the first insulating member 20 covering that area will be too thin, making it easy to be damaged and causing the terminal post 30 to be exposed. When W6 is greater than 2mm, the thickness of the first insulating member 20 covering that area will be too thick, reducing the space utilization rate of the battery.

[0201] As shown in Figures 24, 28, or 33, along the second preset direction Y, the relationship between the maximum length W12 of the second connecting portion 32 and the maximum length W10 of the base portion 3110 of the first connecting portion 31 satisfies: 80% ≤ W10 / W12 ≤ 100%. For example, W10 / W12 can be located within multiple intervals such as 80% ≤ W10 / W12 ≤ 95%, 80% ≤ W10 / W12 ≤ 90%, 80% ≤ W10 / W12 ≤ 85%, etc. In this embodiment, W10 / W12 = 80%, 82%, 84%, 86%, 88%, 90%, 92%, 94%, 95%, 96%, 98%, or 100%, or any value between any two of the above. It can be understood that the maximum length of the base portion 3110 can be equal to or less than the maximum length of the second connecting portion 32. The above configuration allows for the reduction of material usage and the decrease in weight and cost of the pole post 30 while ensuring the welding area of ​​the second connecting part 32 and the first connecting part 31.

[0202] As one embodiment of the pole, please refer to Figures 21, 26, 30 or 35. The second connection portion 32 of the pole 30 includes a main body portion 3230. As one embodiment of the main body portion 3230 of the pole, a second electrical connection portion 3240 is formed at one end of the main body portion 3230 facing the interior of the housing along a third preset direction Z.

[0203] As shown in Figures 21 to 23, or Figures 26, 27, 30, 31, 35, and 36, the main body 3230 includes a third sub-part 3233 and a fourth sub-part 3234, which are stacked along a third preset direction Z. Along the third preset direction Z, on a plane perpendicular to Z, the orthographic projection of the fourth sub-part 3234 falls within the orthographic projection range of the third sub-part 3233; that is, the cross-sectional area of ​​the fourth sub-part 3234 is smaller than the cross-sectional area of ​​the third sub-part 3233. A third stepped surface 3231 connects the sidewall of the fourth sub-part 3234 and the sidewall of the third sub-part 3233. The end surface of the fourth sub-part 3234 away from the third sub-part 3233 is a second electrical connection surface 3232. Along the third preset direction Z, i.e., the thickness direction of the electrode post 30, the third step surface 3231 and the second electrical connection surface 3232 are located on the side of the second connection portion 32 facing the interior of the housing. The second electrical connection surface 3232 extends beyond the third step surface 3231 along the third preset direction Z, meaning that the second electrical connection surface 3232 is located closer to the cell assembly 300 than the third step surface 3231, and the third step surface 3231 is located around the edge side of the second electrical connection portion 3240. The second electrical connection surface 3232 is used to connect with the tab 302. The solder joint depth of the tab 302 and the second electrical connection surface 3232 extends from the tab 302 through the second electrical connection surface 3232 toward the interior of the main body portion 3230. The fact that the second electrical connection surface 3232 extends beyond the third step surface 3231 facilitates direct welding of the tab 302 to the second electrical connection surface 3232, avoiding interference and damage to the tab 302 from other components, and improving the safety of the battery cell 1.

[0204] Since the third step surface 3231 is formed around the side wall of the fourth sub-part 3234, in some embodiments, the third step surface 3231 is located on a plane perpendicular to the third preset direction Z. Thus, as shown in FIG23 or FIG32, on the plane perpendicular to the third preset direction Z, that is, on the plane composed of the first preset direction X and the second preset direction Y, including both the first preset direction X and the second preset direction Y, the width of the third step surface 3231 is W7, which satisfies: 0.3mm≤W7≤1mm. For example, W7 can be located in multiple intervals such as 0.3mm≤W7≤0.8mm, 0.3mm≤W7≤0.5mm, etc. In this embodiment, W7 = 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1mm or any value between any two of the above. Since the positioning tolerance of the pole post 30 is approximately 0.15mm, setting the width W7 of the third step surface 3231 within the aforementioned range provides a certain pressing surface for the welding fixture, enabling welding between the second electrical connection surface 3232 and the electrode tab, while ensuring that the second electrical connection surface 3232 has sufficient welding area. Of course, in some other embodiments, the third step surface 3231 may also have an angle with the plane perpendicular to the third preset direction Z, i.e., the third step surface 3231 is inclined. In this case, the width W7 of the third step surface 3231 on the plane perpendicular to the third preset direction Z is the width of the orthographic projection of the third step surface 3231 onto the plane perpendicular to the third preset direction Z.

[0205] As shown in Figure 23 or Figure 32, along the third preset direction Z, the distance between the third step surface 3231 and the second electrical connection surface 3232 is W8, satisfying: 0.2mm ≤ W8 ≤ 0.7mm; for example, W8 can be located within the range of 0.2mm ≤ W8 ≤ 0.5mm. In this embodiment, W8 = 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, or 0.7mm, or any value between any two of the above. Setting the distance W8 between the third step surface 3231 and the second electrical connection surface 3232 within the above range makes it less likely that the height of the second connection part 32 will be too high, improving the space utilization of the battery and reducing the molding difficulty of the electrode post 30.

[0206] As shown in Figure 23 or Figure 32, the width of the second electrical connection surface 3232 along the first preset direction X is W9. On a plane perpendicular to the third preset direction Z, i.e., on the plane composed of the first preset direction X and the second preset direction Y (including both the first and second preset directions X and Y), the width of the third step surface 3231 is W7, satisfying: 2% ≤ W7 / W9 ≤ 20%. For example, W7 / W9 can be within multiple ranges such as 2% ≤ W7 / W9 ≤ 15%, 2% ≤ W7 / W9 ≤ 10%, 2% ≤ W7 / W9 ≤ 6%, etc. In this embodiment, W7 / W9 = 2%, 6%, 10%, 15%, 20%, etc., or any value between any two of the above. Through the above settings, the second electrical connection surface 3232 has sufficient welding area.

[0207] As shown in Figure 23 or Figure 32, along the first preset direction X, the relationship between the maximum width W13 of the main body 3230 and the maximum width W1 of the first electrical connection 3120 satisfies: 35% ≤ W13 / W1 ≤ 75%. For example, W13 / W1 = 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, or 75%, or any value between any two of the above. Further, 45% ≤ W13 / W1 ≤ 65%. For example, W13 / W1 = 45%, 48%, 50%, 52%, 55%, 57%, 60%, 63%, or 65%, or any value between any two of the above. Through the above settings, the widths of the second connection 32 and the first electrical connection 3120 meet the welding area requirements.

[0208] Understandably, when the main body 3230 does not have a third stepped surface 3231, the width W9 of the second electrical connection surface 3232 is equal to the maximum width W13 of the main body 3230, that is, the entire surface of the main body 3230 facing the cell assembly 300 is used as the second electrical connection surface 3232.

[0209] As shown in Figures 21, 25, 26, 28, 30, 33, 35, and 38, in one embodiment of the pole post, the second connecting portion 32 further includes a first flange portion 3210. The first flange portion 3210 is connected to one end face of the main body portion 3230 along a third preset direction Z and extends toward the base portion 3110. It can be understood that the first flange portion 3210 is a structure bent from the main body portion 3230 toward the base portion 3110. The first flange portion 3210 is connected to the base portion 3110. Along the third preset direction Z, one end of the third sub-part 3233 is connected to the first flange portion 3210, and the opposite end is connected to the fourth sub-part 3234.

[0210] In some embodiments, the first flange portion 3210 is directly connected to the base portion 3110 without a fusible portion, such as the embodiments shown in FIG21 or FIG26. In other embodiments, the first flange portion 3210 may also be connected to the base portion 3110 through a fusible portion, such as the embodiments shown in FIG30 or FIG35.

[0211] As shown in Figures 22, 27, 31, or 36, along the third preset direction Z, the first flange portion 3210 has a second surface 3211 and a fourth surface 3212 opposite to the second surface 3211. The second surface 3211 and the first surface 3111 of the base portion 3110 are located on the same side in the thickness direction of the pole post 30, and the fourth surface 3212 and the third surface 3112 of the base portion 3110 are located on the same side in the thickness direction of the pole post 30. It can be understood that both the second surface 3211 and the first surface 3111 are located on the side of the pole post 30 facing the outside of the shell. Both the third surface 3112 and the fourth surface 3212 are located on the side of the pole post 30 facing the inside of the shell. The second surface 3211 and the first surface 3111 are in the same plane and form surface A. That is, the area of ​​the first surface 3111 of the base portion 3110 and the area of ​​the second surface 3211 of the first flange portion 3210 of the second connecting portion 32 together constitute the surface A of the pole post 30. The third surface 3112 and the fourth surface 3212 are on the same plane and form surface B. That is, the area of ​​the third surface 3112 of the base part 3110 and the area of ​​the fourth surface 3212 of the first flange part 3210 of the second connecting part 32 together constitute the surface B of the pole post 30.

[0212] The second surface 3211 of the first flange portion 3210 and the first surface 3111 of the base portion 3110 are disposed on the same plane to form surface A. The fourth surface 3212 of the first flange portion 3210 and the third surface 3112 of the base portion 3110 are disposed on the same plane to form surface B. On the one hand, the electrode post can be stamped by pressing the surfaces A and B with a mold, making the processing of the electrode post more convenient. On the other hand, while ensuring that the first connecting portion 31 and the second connecting portion 32 have sufficient welding area, the width dimension of the electrode post 30 can be reduced, so that it can be applied to the battery cell 1 with limited design space in the top cover assembly 100 without affecting the performance of the battery cell 1. In other words, when the width dimension of the electrode post 30 is fixed, the weldable area of ​​the first connecting portion 31 or the second connecting portion 32 can be increased.

[0213] As shown in Figure 23 or Figure 32, on a plane perpendicular to the second preset direction Y, that is, on the plane composed of the first preset direction X and the third preset direction Z, the angle between the side wall of the main body 3230 near the base part 3110 and the fourth surface 3212 is α, satisfying: 90°≤α≤95°. This creates a draft angle of 0–5° on the side wall of the main body 3230, facilitating smooth demolding. Understandably, the entire circumferential side wall of the main body 3230 has a draft angle of 0–5° to facilitate easy demolding of the main body 3230 as a whole.

[0214] Referring to Figures 25 or 29, the fourth surface 3212 of the first flange portion 3210 is connected to the side wall surface of the main body portion 3230 via a first arc segment 3250. It can be understood that the fourth surface 3212 of the first flange portion 3210 and the side wall surface of the main body portion 3230 are connected by an arc transition via the first arc segment 3250. This arc transition between the fourth surface 3212 of the first flange portion 3210 and the side wall surface of the main body portion 3230 facilitates the processing of the pole post 30 and also facilitates demolding after processing.

[0215] Please refer to Figures 22, 27, or 31. Along the first preset direction X, the distance between the side of the first flange portion 3210 and the side of the main body portion 3230 is c, which satisfies: 0.5mm≤c≤5mm. For example, c can be located within multiple intervals such as 0.5mm≤c≤4mm, 0.5mm≤c≤3mm, 0.8mm≤c≤3mm, 0.5mm≤c≤2mm, 0.9mm≤c≤2mm, 0.5mm≤c≤1.5mm, and 1.0mm≤c≤1.5mm. In this embodiment, c = 0.5mm, 0.7mm, 0.8mm, 0.9mm, 1.1mm, 1.3mm, 1.5mm, 1.7mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.5mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.2mm, 3.4mm, 3.6mm, 3.7mm, 4.2mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm, or 5.0mm, or any value between any two of the above. The side of the first flange portion 3210 can be understood as the edge side of the first flange portion 3210 along the first preset direction X. The side of the main body portion 3230 can be understood as the edge side of the main body portion 3230 along the first preset direction X. When the side wall of the main body portion 3230 has a draft angle greater than 0° and less than or equal to 5°, the distance c refers to the minimum distance between the side of the first flange portion 3210 and the side of the main body portion 3230. Through the above arrangement, on the one hand, the first flange portion 3210 has sufficient width to facilitate the die pressing on the first flange portion 3210 to punch the outer contour of the pole post 30, and on the other hand, the first flange portion 3210 is not too wide, thereby affecting the total width of the pole post 30.

[0216] As another embodiment of the second connecting portion 32 of the pole post 30, please refer to Figures 21, 22, 26, 27, 30, 31, 35, and 36. The second connecting portion 32 includes a first flange portion 3210 and a second flange portion 3220. The second flange portion 3220 is connected to one end face of the main body portion 3230 along a third preset direction Z and extends in a direction away from the base portion 3110. That is, the first flange portion 3210 and the second flange portion 3220 are arranged opposite to each other along the first preset direction X. Along the third preset direction Z, the second flange portion 3220 has a fifth surface 3221 and a sixth surface 3222 arranged opposite to the fifth surface 3221. The fifth surface 3221 and surface A are located on the same side in the pole post thickness direction. That is, the fifth surface 3221 and surface A are both located on the side facing the outside of the housing, and the sixth surface 3222 is located on the side facing the inside of the housing. The fifth surface 3221 is coplanar with surface A and forms surface C. That is, the fifth surface 3221, together with the regions of the first surface 3111 and the second surface 3211 that make up surface A, constitutes surface C. The sixth surface 3222 is coplanar with surface B and forms surface D. That is, the sixth surface 3222, together with the regions of the third surface 3112 and the fourth surface 3212 that make up surface B, constitutes surface D. Thus, the base portion 3110 of the first connecting portion 31 and the first flange portion 3210 and the second flange portion 3220 of the second connecting portion 32 are coplanar. The surface of the base portion 3110 facing outwards from the shell is coplanar with the surfaces of the first flange portion 3210 and the second flange portion 3220 facing outwards from the shell, i.e., surface C. The surface of the base portion 3110 facing inwards from the shell is coplanar with the surfaces of the first flange portion 3210 and the second flange portion 3220 facing inwards from the shell, i.e., surface D. Surfaces C and D are parallel. In the processing of the electrode post 30, the various structural parts of the electrode post 30 are first formed on a strip of raw material of a certain length through a stamping process (such as upsetting and deep drawing). Finally, the outer contour of the electrode post 30, namely the outer contour of the base part 3110 and the outer contour of the first electrical connection part 3120, is punched, so that the electrode post 30 is successfully dropped from the strip. With this setting, when the electrode post 30 is punched, the thickness of the punched surface is uniform and there is no height difference on the punched surface. The outermost contour of the electrode post 30 can be punched out in the last step of the punching process, resulting in fewer punching burrs.

[0217] Furthermore, as shown in Figures 22, 27, 31 or 36, along the first preset direction X, the distance between the side of the second flange portion 3220 and the side of the main body portion 3230 is d, which satisfies: 0.5mm≤d≤5mm. For example, d can be located within multiple intervals such as 0.5mm≤d≤4mm, 0.5mm≤d≤3mm, 0.8mm≤d≤3mm, 0.5mm≤d≤2mm, 0.9mm≤d≤2mm, 0.5mm≤d≤1.5mm, and 1.0mm≤d≤1.5mm. In this embodiment, d = 0.5mm, 0.7mm, 0.8mm, 0.9mm, 1.1mm, 1.3mm, 1.5mm, 1.7mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.5mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.2mm, 3.4mm, 3.6mm, 3.7mm, 4.2mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm, or 5.0mm, or any value between any two of the above. The side of the second flange portion 3220 can be understood as the edge side of the second flange portion 3220 along the first preset direction X. When the side wall of the main body portion 3230 has a draft angle greater than 0° and less than or equal to 5°, the distance d refers to the minimum distance between the side of the second flange portion 3220 and the side of the main body portion 3230. Through the above arrangement, on the one hand, the second flange portion 3220 has sufficient width to facilitate the die pressing on the second flange portion 3220 to punch the outer contour of the pole post 30, and on the other hand, the second flange portion 3220 is not too wide, so that the total width of the pole post 30 is not too large.

[0218] Since the first flange 3210 is closer to the base portion 3110 of the first connecting portion 31 than the second flange 3220, current flows through the first flange 3210. Therefore, in some embodiments, the distance c between the side of the first flange 3210 and the side of the main body 3230 is smaller than the distance d between the side of the second flange 3220 and the side of the main body 3230. This results in a relatively shorter current path for the first flange 3210, leading to better current flow performance.

[0219] In some embodiments, referring to Figures 25, 29, or 34, the sixth surface 3222 of the second flange portion 3220 is connected to the side wall surface of the main body portion 3230 via a second arc segment 3260. It is understood that the sixth surface 3222 of the second flange portion 3220 and the side wall surface of the main body portion 3230 are transitionally connected via the second arc segment 3260, thereby facilitating the processing of the pole post 30 and the demolding of the mold.

[0220] In some other embodiments, referring to Figures 21, 26, 27, or 35, the second connecting portion 32 includes a first flange 3210, a second flange 3220, a third flange 32110, and a fourth flange 32120. The third flange 32110 and the fourth flange 32120 are connected to one end face of the main body 3230 along a third preset direction Z and extend away from the main body 3230. Along the circumference of the second connecting portion 32, the first flange 3210, the third flange 32110, the second flange 3220, and the fourth flange 32120 are connected end to end in sequence. Since the first flange portion 3210 and the second flange portion 3220 are arranged opposite each other along the width direction of the second connecting portion 32, i.e., along the first preset direction X, and the third flange portion 32110 and the fourth flange portion 32120 are arranged opposite each other along the length direction of the second connecting portion 32, i.e., along the second preset direction Y, the third flange portion 32110 is connected to one end of the first flange portion 3210 and the second flange portion 3220, and the fourth flange portion 32120 is connected to the other end of the first flange portion 3210 and the second flange portion 3220. The third flange portion 32110 and the fourth flange portion 32120 can be arc-shaped or straight-shaped. Preferably, the third flange portion 32110 and the fourth flange portion 32120 are arc-shaped. The surfaces of the third flange portion 32110 and the fourth flange portion 32120 facing the outside of the shell are on the same plane as surface C. The surfaces of the third flange 32110 and the fourth flange 32120 facing the interior of the housing are on the same plane as surface D. As a result, when the pole post 30 is punched, the thickness of the punched surface is uniform and there is no height difference on the punched surface. The outermost contour of the pole post 30 can be punched out in the last step of punching, resulting in fewer punching burrs.

[0221] It is understood that the first flange 3210, the second flange 3220, the third flange 32110, and the fourth flange 32120 constitute flanges, which is one embodiment of the second region 322 of the second connecting portion 32 in the above embodiments. The main body 3230 of the second connecting portion 32 is one embodiment of the first region 321 of the second connecting portion 32 in the above embodiments. Specifically, the surfaces of the third flange 32110 and the fourth flange 32120 facing the outside of the housing, together with the second surface 3211 of the first flange 3210 and the fifth surface 3221 of the second flange 3220, form the fourth surface b4 of the second connecting portion 32. The surfaces of the third flange 32110 and the fourth flange 32120 facing the inside of the housing, together with the fourth surface 3212 of the first flange 3210 and the sixth surface 3222 of the second flange 3220, form the fifth surface b5 of the second connecting portion 32.

[0222] In some embodiments, as shown in Figures 22, 27, 31, and 36, the distance between surface C and surface D along the third preset direction Z is W5, satisfying: 0.5mm ≤ W5 ≤ 3mm. For example, W5 = 0.5mm, 0.7mm, 0.8mm, 0.9mm, 1.1mm, 1.3mm, 1.5mm, 1.7mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.5mm, 2.7mm, 2.8mm, 2.9mm, or 3mm, or any value between any two of the above. Preferably, 0.8mm ≤ W5 ≤ 1.5mm. For example, W5 = 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, or 1.5mm, or any value between any two of the above. This setting ensures the electrode has a certain flow area and facilitates processing. When W5 is less than 0.5mm, the flow area between surface C and surface D of the electrode post is small, making this location prone to deformation. When W5 is greater than 3mm, the thickness between surface C and surface D is large, increasing the cost and height of the electrode post 30, reducing the space utilization of the battery cell 1 and the battery. At the same time, when processing the electrode post, it is difficult to stamp out the first electrical connection portion 3120 that extends beyond the base portion 3110, increasing the processing difficulty.

[0223] As one embodiment of the pole post, referring to Figures 25, 29, or 34, the main body 3230 of the second connecting portion 32 includes a first sidewall 3237 and a second sidewall 3235. The first sidewall 3237 and the second sidewall 3235 are disposed opposite each other along a first preset direction X. One end face of the first sidewall 3237 along a third preset direction Z is connected to a first flange portion 3210, which extends from the first sidewall 3237 toward the base portion 3110. The first sidewall 3237 can be straight. One end face of the second sidewall 3235 along the third preset direction Z is connected to a second flange portion 3220. The second flange portion 3220 extends from the second sidewall 3235 in a direction away from the base portion 3110. The second sidewall 3235 can be straight.

[0224] Since the first sidewall 3237 connects to the first flange 3210, current flows through both the first sidewall 3237 and the first flange 3210. Therefore, along the first preset direction X, the thickness of the first sidewall 3237 is greater than the thickness of the second sidewall 3235, thereby increasing the current-carrying area of ​​the first sidewall 3237. Since current does not flow through the second sidewall 3235, the thickness of the second sidewall 3235 can be set to be less than the thickness of the first sidewall 3237, thereby reducing the overall weight of the electrode post 30, saving material, and also reducing the width dimension of the electrode post 30.

[0225] In some other embodiments, referring to Figures 24, 28, or 33, the main body 3230 includes a first sidewall 3237, a second sidewall 3235, a third sidewall 3236, and a fourth sidewall 3238, wherein the first sidewall 3237, the third sidewall 3236, the second sidewall 3235, and the fourth sidewall 3238 are connected end-to-end along the circumference of the main body 3230. The first sidewall 3237 and the second sidewall 3235 are arranged opposite to each other, and the third sidewall 3236 and the fourth sidewall 3238 are arranged opposite to each other. One end face of the third sidewall 3236 along a third preset direction Z is connected to the third flange portion 32110. One end face of the fourth sidewall 3238 along the third preset direction Z is connected to the fourth flange portion 32120. The third sidewall 3236 and the fourth sidewall 3238 can be curved (e.g., arc-shaped) or straight. In some embodiments, the third sidewall 3236 and the fourth sidewall 3238 are arc-shaped. It is understood that the first sidewall 3237, the third sidewall 3236, the second sidewall 3235 and the fourth sidewall 3238 form the annular sidewall 3245 in the above embodiments.

[0226] As one embodiment of the electrode post, as shown in Figures 21 to 38, the second connecting portion 32 has a first groove 323, which is recessed from surface A into the interior of the main body portion 3230. That is, the first groove 323 extends from surface A into the interior of the main body portion 3230. The opening of the first groove 323 is located on surface A. The opening of the first groove 323 may be higher than the side surface of the cover plate 10 away from the interior of the housing. A second electrical connection portion 3240 is formed on the bottom wall of the first groove 323 and is connected to the tab 302, thereby making the second connecting portion 32 form a hollow structure, reducing the overall weight of the electrode post 30 and saving materials. It should be noted that the groove depth of the first groove 323 needs to take into account the weld penetration depth of the second electrical connection portion 3240 and the tab 302, the material utilization rate, and the space utilization rate inside the housing, and the welding quality of both needs to be guaranteed while saving materials.

[0227] In some embodiments, on a plane perpendicular to the second preset direction Y, i.e., on the plane composed of the first preset direction X and the third preset direction Z, the angle between the groove wall surface of the first groove 323 near the base portion 3110 and the fourth surface 3212 is β, satisfying: 90°≤β≤95°. This creates a draft angle of 0–5° on the groove wall surface of the first groove 323, facilitating smooth mold demolding. Since the first groove 323 can be formed by a first sidewall 3237, a second sidewall 3235, a third sidewall 3236, a fourth sidewall 3238, and a groove bottom wall, and the inner sidewall of the first sidewall 3237 facing the first groove 323 is parallel to the outer sidewall facing away from the first groove 323, the groove wall surface of the first groove 323 also has an angle of 90°≤β≤95° with the fourth surface 3212, further facilitating demolding. Understandably, the entire circumferential groove wall of the first groove 323 has a draft angle of 0 to 5° to facilitate mold demolding.

[0228] In some embodiments, as shown in Figures 18 and 19, the bottom surface 32301 of the first groove 323 is located between the upper and lower surfaces of the cover plate 10. The upper surface of the cover plate 10 refers to the surface of the cover plate 10 facing the outside of the housing. The lower surface of the cover plate 10 refers to the surface of the cover plate 10 facing the inside of the housing. This ensures the welding penetration between the second electrical connection portion 3240 and the tab 302, while reducing the overall height of the electrode post 30, thereby reducing the processing difficulty of the electrode post 30. In addition, it can save material of the electrode post 30 and improve the space utilization rate inside the battery cell 1.

[0229] In some embodiments, referring to Figures 25, 29, or 34, the groove wall surface and the groove bottom surface 32301 of the first groove 323 are connected by a third arc segment 3270. It is understood that the arc transition between the groove wall surface and the groove bottom surface 32301 of the first groove 323 via the third arc segment 3270 facilitates the processing and demolding of the first groove 323.

[0230] In some embodiments, referring to Figures 25, 29, or 34, when the main body 3230 has a first groove 323, the groove wall surface of the first groove 323 is connected to the second surface 3211 of the first flange 3210 via a fourth arc segment 3280. It is understood that the groove wall surface of the first groove 323 and the second surface 3211 of the first flange 3210 are transitioned by the fourth arc segment 3280, thus facilitating demolding after the first groove 323 is punched out by the electrode post 30. In some embodiments, the groove wall surface of the first groove 323 is connected to the fifth surface 3221 of the second flange 3220 via a fifth arc segment 3290. It is understood that the groove wall surface of the first groove 323 and the fifth surface 3221 of the second flange 3220 are transitioned by the fifth arc segment 3290. This facilitates demolding after the first groove 323 is punched out by the electrode post 30.

[0231] Of course, the electrode post 30 in this application can be a positive electrode post, as shown in the embodiments of Figures 21 to 25 or Figures 30 to 34; the electrode post 30 in this application can also be a negative electrode post, as shown in the embodiments of Figures 26 to 29 or Figures 35 to 38. When the electrode post 30 is a negative electrode post, the second connecting portion 32 includes a first metal layer 326 and a second metal layer 327. Along the direction from surface C to surface D, the first metal layer 326 and the second metal layer 327 are stacked, with the second metal layer 327 located on the side of the first metal layer 326 facing the interior of the housing. The first metal layer 326 can be connected to the first connecting portion 31 and is made of the same material. The second metal layer 327 covers the outside of the first metal layer 326. The second metal layer 327 is directly in contact with the negative electrode tab for welding. In this embodiment, the first metal layer 326 is an aluminum layer, and the second metal layer 327 is a copper layer. Since the negative electrode tab of the battery cell assembly 300 is generally made of copper, the second metal layer 327 is made of the same material as the negative electrode tab in order to improve the welding effect of the negative electrode post and the negative electrode tab.

[0232] In some embodiments, a portion of the interface between the first metal layer 326 and the second metal layer 327 intersects with the sidewall surface of the second flange portion 3220, as shown in Figures 26, 29, 35, and 38. The portion of the interface between the first metal layer 326 and the second metal layer 327 may also intersect with the sidewall surfaces of the third flange portion 32110 and the fourth flange portion 32120, as shown in Figure 26 or 35. The portion of the interface between the first metal layer 326 and the second metal layer 327 may also intersect with the sidewall surface of the first flange portion 3210, as shown in Figure 35. It is understood that the sidewall surfaces refer to the circumferential side surfaces of the first flange portion 3210, the second flange portion 3220, the third flange portion 32110, and the fourth flange portion 32120. Since the first flange 3210, the second flange 3220, the third flange 32110, and the fourth flange 32120 are located on the side of the cover plate 10 facing the outside of the housing, the interface between the first metal layer 326 and the second metal layer 327 can extend to the circumferential side of the first flange 3210, the second flange 3220, the third flange 32110, and the fourth flange 32120 and be located on the outside of the cover plate 10. This avoids the first metal layer 326, which is an aluminum layer, from contacting the electrolyte inside the housing and corroding, thereby affecting the safety performance of the battery.

[0233] As a preferred embodiment of the electrode post, as shown in Figures 30 or 35, the electrode post 30 may further include a fusible portion 35, which connects the first connecting portion 31 and the second connecting portion 32. As shown in Figures 31 or 36, along the third preset direction Z, the fusible portion 35 has a seventh surface 3510 and an eighth surface 3520 disposed opposite to each other, wherein the seventh surface 3510 is in the same plane as surface A, and the eighth surface 3520 is in the same plane as surface B. This arrangement facilitates the stamping and forming of the electrode post 30, making its processing more convenient.

[0234] The fusible link can refer to a structural component that melts preferentially over the first connection 31 and the second connection 32 when thermal runaway occurs in the battery cell 1. This allows the fusible link 35 to promptly disconnect the circuit in the event of thermal runaway within the battery cell 1.

[0235] To ensure that the fuse portion 35 melts preferentially before the first connection portion 31 and the second connection portion 32 in the event of thermal runaway in battery cell 1, as shown in Figure 30, the length of the fuse portion 35 along the second preset direction Y is less than the length of the first connection portion 31 and less than the length of the second connection portion 32. This makes the current-carrying area of ​​the fuse portion 35 smaller than that of the first connection portion 31 and less than that of the second connection portion 32. The current-carrying area of ​​the fuse portion 35 refers to the surface area of ​​the fuse portion 35 perpendicular to the current flow direction, i.e., the minimum cross-sectional area of ​​the fuse portion 35. The current-carrying areas of the first connection portion 31 and the second connection portion 32 refer to the surface areas of the first connection portion 31 and the second connection portion 32 perpendicular to the current flow direction, i.e., the minimum cross-sectional areas of the first connection portion 31 and the second connection portion 32. Thus, in actual use, when a circuit malfunction occurs, the smaller current-carrying area of ​​the fuse portion 35 allows for faster temperature rise at the fuse portion 35, enabling it to melt quickly and promptly disconnect the circuit, greatly improving battery safety.

[0236] Understandably, the fuse part 35 can also reduce the current-passing area by slotting or opening, so as to ensure that the fuse can be blown in time to cut off the circuit when the circuit is abnormal.

[0237] Referring to Figures 18 to 20, as a preferred embodiment of the first insulating member 20, the first insulating member 20 of this application includes a third insulating portion 210, a second insulating portion 220, and a first insulating portion 230. The third insulating portion 210 is disposed on the side of the cover plate 10 facing the interior of the housing. It is understood that the third insulating portion 210, disposed on the side of the cover plate 10 facing the interior of the housing and forming an insulation with the second connecting portion 32, can prevent the second connecting portion 32 from contacting and electrically connecting with the cover plate 10. Along the third preset direction Z, at least a portion of the orthographic projection of the third insulating portion 210 falls on the cover plate 10; that is, on a plane perpendicular to the third preset direction Z, the orthographic projection of the third insulating portion 210 overlaps with the orthographic projection of the cover plate 10. It is understood that at least a portion of the third insulating portion 210 is bent towards the inner side of the cover plate 10 below the wall of the first through hole 11.

[0238] The second insulating portion 220 is disposed between the wall of the first through hole 11 and the second connecting portion 32 of the electrode post 30, so as to connect the second connecting portion 32 and the wall of the first through hole 11 through the second insulating portion 220 and form insulation, and at the same time, it can play a sealing role to prevent electrolyte from leaking out of the first through hole 11. The second insulating portion 220 can be in the form of a ring structure, with one end of the second insulating portion 220 facing the inside of the housing connected to the third insulating portion 210, and the other end of the second insulating portion 220 facing the outside of the housing connected to the first insulating portion 230.

[0239] The first insulating portion 230 is disposed on the side of the cover plate 10 facing the outside of the housing. The first insulating portion 230 includes the first insulator portion 21, the second insulator portion 22, and the third insulator portion 23 in the above embodiments. That is, the first insulating portion 230 is disposed on the outside of the cover plate 10 to insulate the pole portion of the cover plate 10 facing the outside of the housing and the cover plate 10. At the same time, the first insulating portion 230 can also play a sealing role. Along the third preset direction Z, at least a portion of the orthographic projection of the first insulating portion 230 falls on the cover plate 10. That is, on the plane perpendicular to the third preset direction Z, the orthographic projection of the first insulating portion 230 overlaps with the orthographic projection of the cover plate 10. It can be understood that the outer contour edge of the first insulating portion 230 extends beyond the hole wall of the first through hole 11.

[0240] First, the third insulating part 210 and the second insulating part 220 are connected as a whole, forming an L-shape, which allows them to interlock with the cover plate 10, improving the fixation effect on the terminal post 30. Furthermore, when at least a portion of the orthographic projection of the first insulating part 230 falls on the cover plate 10, the third insulating part 210 and the first insulating part 230 can jointly clamp the cover plate 10 from both sides in the thickness direction, further improving the fixation effect on the terminal post 30. Secondly, the sealing ring structure in the top cover assembly 100 of related technologies can be eliminated, thus eliminating the size requirement of the sealing ring in the width direction of the cover plate 10. Therefore, only the dimensions of the outer casing film folded at the edge of the cover plate 10 to the edge of the first insulating member 20, the dimensions of the two second connecting parts 32, and the dimensions of the first connecting part 31 need to be considered. Even for a thin battery cell 1 with a limited design width, the welding area of ​​the first connecting part 31 and the second connecting part 32 can be guaranteed, thus not affecting the battery's charging and discharging performance and safety performance. Finally, the second insulating part 220 is inserted into the first through hole 11, which can prevent the electrolyte from leaking out of the first through hole 11 due to compression failure of the sealing ring during long-term use. Furthermore, the third insulating part 210, the second insulating part 220 and the first insulating part 230 are connected as one unit, which can increase the sealing path for sealing the hole wall of the first through hole 11, further preventing the electrolyte from leaking out of the first through hole 11.

[0241] In this embodiment, the third insulating portion 210, the second insulating portion 220, and the first insulating portion 230 of the first insulating member 20 are integrally formed. Furthermore, the third insulating portion 210, the second insulating portion 220, and the first insulating portion 230 are integrally nano-injection molded. Nano-injection molding is a process technology that tightly bonds metal and plastic. By integrally nano-injection molding the third insulating portion 210, the second insulating portion 220, and the first insulating portion 230, the sealing performance of the battery cell 1 can be greatly improved, thus further ensuring that the sealing ring can be eliminated in this application. Of course, in some other embodiments, the third insulating portion 210, the second insulating portion 220, and the first insulating portion 230 can also be formed separately first, and then connected by bonding, heat fusion, or other methods.

[0242] In this embodiment, the surfaces of the cover plate 10 that contact the third insulating portion 210 and the second insulating portion 220 are provided with first nanopores, and at least a portion of the third insulating portion 210 and the second insulating portion 220 are embedded in the first nanopores; this can increase the bonding force and sealing performance between the third insulating portion 210 and the second insulating portion 220 and the cover plate 10. During the manufacturing process, a nanopore structure can be formed on the lower surface of the cover plate 10 and the hole wall of the first through hole 11 by chemical etching, thereby increasing the contact surface area of ​​the third insulating portion 210, the second insulating portion 220 and the cover plate 10, and improving the bonding force and sealing performance.

[0243] In some embodiments, the surfaces of the electrode post 30 that contact the third insulating portion 210 and the second insulating portion 220 are provided with second nanopores, and the third insulating portion 210 and the second insulating portion 220 are at least partially embedded in the second nanopores. During the manufacturing process, a nanopore structure can be formed on the circumferential side surface of the second connecting portion 32 of the electrode post 30 by chemical etching to increase the contact surface area with the third insulating portion 210 and the second insulating portion 220, thereby improving the bonding force and sealing performance between the third insulating portion 210 and the second insulating portion 220 and the electrode post 30.

[0244] In some embodiments, the surface of the cover plate 10 in contact with the first insulating portion 230 is provided with a third nanopore, and at least a portion of the first insulating portion 230 is embedded in the third nanopore. During the manufacturing process, a nanopore structure can be formed on the outer surface of the cover plate 10, the bottom surface of the fifth groove 14, and the groove wall surface by chemical etching, thereby increasing the contact surface area between the first insulating portion 230 and the cover plate 10 and improving the bonding force and sealing performance between the first insulating portion 230 and the cover plate 10.

[0245] In some embodiments, the surface of the pole post 30 that contacts the first insulating portion 230 is provided with a fourth nanopore, and at least a portion of the first insulating portion 230 is embedded in the fourth nanopore. During the manufacturing process, nanoporous structures can be formed on surface C, surface D, the bottom surface 32301 and wall surface of the first groove 323 of the second connecting portion 32, the circumferential side surfaces of the second flange portion 3220, the third flange portion 32110 and the fourth flange portion 32120, and the circumferential side surface of the base portion 3110 of the first connecting portion 31 by chemical etching. Alternatively, in some other embodiments, nanoporous structures can be formed on surface C, surface D, the bottom surface 32301 and wall surface of the first groove 323 of the second connecting portion 32, the circumferential side surfaces of the second flange portion 3220, the third flange portion 32110 and the fourth flange portion 32120, the circumferential side surface of the base portion 3110 of the first connecting portion 31, and the upper and lower surfaces of the fused portion 35 by chemical etching. This increases the contact surface area between the first insulating portion 230 and the pole post 30, and improves the bonding force and sealing performance between the first insulating portion 230 and the pole post 30.

[0246] As one embodiment of the top cover assembly 100, please refer to Figures 18 to 20. The cover plate 10 may also be provided with a second insulating member 50. The second insulating member 50 is provided on the surface of the cover plate 10 facing the inside of the housing, and is used to insulate the cover plate 10 and the cell assembly 300 to reduce the risk of short circuit. For example, the second insulating member 50 may be a plastic material, such as PP, PE, PPS, etc.

[0247] In this embodiment, referring to FIG20, the second insulating member 50 is provided with a third through hole 501 corresponding to the first through hole 11. The third through hole 501 penetrates the thickness direction of the second insulating member 50. The second connecting part 32 passes through the first through hole 11 and the third through hole 501 in sequence so that the second connecting part 32 can be welded to the tab 302.

[0248] The cover plate 10 may also be provided with a pressure relief mechanism 7 for releasing internal pressure when the internal pressure or temperature of the battery cell 1 reaches a threshold. The surface of the pressure relief mechanism 7 facing the outer side of the casing is provided with a protective layer 71 to protect the pressure relief mechanism 7. By providing a pressure relief mechanism 7 on the cover plate 10, it is less likely for the battery cell 1 to experience thermal runaway.

[0249] In all the above embodiments, optionally, in the third preset direction, the second surface (3211) is located between the first electrical connection surface (3122) and the third surface (3112).

[0250] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0251] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A pole, characterized in that It includes at least one first connecting portion (31) and at least two second connecting portions (32), the at least two second connecting portions (32) are arranged at intervals along a first preset direction (X), and a first connecting portion (31) is provided between each two adjacent second connecting portions (32), and each first connecting portion (31) is connected to the two adjacent second connecting portions (32); the first connecting portion (31) is used to connect with an electrical connector, and one side of the first connecting portion (31) in a third preset direction (Z) is a third surface (3112); each second connecting portion (32) extends beyond the third surface (3112) of the first connecting portion (31) along the third preset direction (Z), and the second connecting portion (32) is used to connect with a tab; the third preset direction (Z) and the first preset direction (X) intersect.

2. The pole according to claim 1, characterized in that The first connecting portion (31) has a first electrical connection surface (3122) opposite to the third surface (3112) in the third preset direction, and the second connecting portion has a second surface (3211). In the third preset direction, the second surface (3211) and the first electrical connection surface (3122) are located on the same side of the pole and between the first electrical connection surface (3122) and the third surface (3112).

3. The pole post according to claim 1 or 2, characterized in that, The first connecting portion (31) includes a base portion (3110) and a first electrical connecting portion (3120). The base portion (3110) has the third surface (3112), and the first electrical connecting portion (3120) has the first electrical connecting surface (3122). Along the third preset direction (Z), the base portion (3110) has a first surface (3111) disposed opposite to the third surface (3112), and the first electrical connecting portion (3120) is disposed on the surface of the base portion (3110) having the first surface (3111). The second connecting portion (32) includes a main body portion (3230) and a first flange portion (3210). The first flange portion (3210) is connected to one end face of the main body portion (3230) along the third preset direction (Z) and extends toward the base portion (3110). The first flange portion (3210) is connected to the base portion (3110). Along the third preset direction (Z), the first flange portion (3210) has a second surface (3211). The second surface (3211) and the first surface (3111) are located on the same side in the thickness direction of the pole post, and the second surface (3211) and the first surface (3111) are in the same plane and form a surface (A).

4. The pole according to claim 3, characterized in that Along the third preset direction (Z), the first flange portion (3210) has a fourth surface (3212) that is disposed opposite to the second surface (3211), the third surface (3112) and the fourth surface (3212) are in the same plane and form a surface (B).

5. The electrode post according to claim 3, characterized in that, The second connecting portion (32) further includes a second flange portion (3220), which is connected to one end face of the main body portion (3230) along the third preset direction (Z) and extends in a direction away from the base portion (3110). The second flange portion (3220) is disposed opposite to the first flange portion (3210) along the first preset direction (X). Along the third preset direction (Z), the second flange portion (3220) has a fifth surface (3221), which is in the same plane as the surface (A) and forms a surface (C). Along the third preset direction (Z), the second flange (3220) also has a sixth surface (3222) disposed opposite to the fifth surface (3221), the sixth surface (3222) being in the same plane as the surface (B) and forming a surface (D), wherein the surface (C) and the surface (D) are parallel.

6. The pole according to claim 5, characterized in that The second connecting part (32) further includes a third flange (32110) and a fourth flange (32120). Along the second preset direction (Y), the third flange (32110) connects one end of the first flange (3210) and the second flange (3220), and the fourth flange (32120) connects the other end of the first flange (3210) and the second flange (3220). The second preset direction (Y), the first preset direction (X) and the third preset direction (Z) are arranged to intersect each other.

7. The pole according to claim 6, characterized in that Both the third flange (32110) and the fourth flange (32120) are arc-shaped.

8. The pole according to claim 5, wherein The second connecting portion (32) includes a first metal layer (326) and a second metal layer (327) in a direction from the surface (C) to the surface (D). The first metal layer (326) and the second metal layer (327) are stacked, wherein at least a portion of the interface between the first metal layer (326) and the second metal layer (327) intersects with the sidewall surface of the second flange portion (3220).

9. The pole according to claim 8, characterized in that The first connecting portion (31) includes the first metal layer (326), and the first metal layer (326) and the second metal layer (327) of the second connecting portion (32) are both connected to the first metal layer (326) of the first connecting portion (31).

10. The pole according to claim 8, wherein The first connecting portion (31) includes a first metal layer (326) and a second metal layer (327) stacked together. The first metal layer (326) of the second connecting portion (32) is connected to the first metal layer (326) of the first connecting portion (31), and the second metal layer (327) of the second connecting portion (32) is connected to the second metal layer (327) of the first connecting portion (31).

11. The pole according to claim 8, wherein The main body (3230) includes an annular sidewall (3245) and a bottom wall (3247). Along the third preset direction (Z), one end of the annular sidewall (3245) is connected to the first flange (3210), and the other end of the annular sidewall (3245) is connected to the bottom wall (3247). The thickness T5 of the second metal layer (327) at the bottom wall (3247) is 0.3 mm to 1.8 mm; and / or, the thickness T5 of the second metal layer (327) at the bottom wall (3247) accounts for 10% to 40% of the thickness of the bottom wall (3247).

12. The pole according to any one of claims 8-10, characterized in that The first metal layer (326) is an aluminum layer, and the second metal layer (327) is a copper layer.

13. The pole post according to claim 5, characterized in that, Along the first preset direction (X), the distance between the side of the first flange (3210) and the side of the main body (3230) is c, which satisfies: 0.5mm≤c≤5mm; And / or, Along the first preset direction (X), the distance between the side of the second flange (3220) and the side of the main body (3230) is d, which satisfies: 0.5mm≤d≤5mm; And / or, Along the first preset direction (X), the distance c between the side of the first flange (3210) and the side of the main body (3230) is less than the distance d between the side of the second flange (3220) and the side of the main body (3230); And / or, Along the second preset direction (Y), the minimum distance between the edge side of the first electrical connection part (3120) and the edge side of the base part (3110) is a, which satisfies: 0.2mm≤a≤5mm; And / or, Along the third preset direction (Z), the distance between the upper and lower surfaces of the base part (3110) is W5, which satisfies: 0.5mm≤W5≤3mm.

14. The pole according to any one of claims 1-3, characterized in that Also includes: A fusible portion (35) is connected between the first connecting portion (31) and the second connecting portion (32) along the third preset direction (Z). The fusible portion (35) has a seventh surface (3510) and an eighth surface (3520) arranged opposite to each other, wherein the seventh surface (3510) is in the same plane as surface (A); and / or, the eighth surface (3520) is in the same plane as surface (B).

15. The pole according to any one of claims 1-3, wherein The first electrical connection portion (3120) includes a first sub-part (3123) and a second sub-part (3124). Along the third preset direction (Z), one end of the first sub-part (3123) is connected to the base portion (3110), and the other end is connected to the second sub-part (3124). Along the third preset direction (Z), on a plane perpendicular to the third preset direction (Z), the orthographic projection of the second sub-part (3124) falls within the orthographic projection range of the first sub-part (3123). A second step surface (3121) is connected between the side wall surface of the first sub-part (3123) and the side wall surface of the second sub-part (3124). The surface of the second sub-part (3124) away from the first sub-part (3123) is the first electrical connection surface (3122).

16. The pole post according to claim 15, characterized in that, On a plane perpendicular to the third preset direction (Z), the width of the second step surface (3121) is W3, satisfying: 0.3mm ≤ W3 ≤ 1mm; and / or, Along the third preset direction (Z), the distance between the second step surface (3121) and the first electrical connection surface (3122) is W4, satisfying: 0.2mm ≤ W4 ≤ 0.7mm; and / or, Along the third preset direction (Z), the distance between the second step surface (3121) and the first electrical connection surface (3122) is W4, and the distance between the first electrical connection surface (3122) and the surface (A) is W6, satisfying: 15% ≤ W4 / W6 ≤ 50%; and / or, Along the first preset direction (X), the maximum width of the first electrical connection portion (3120) is W1, and on the plane perpendicular to the third preset direction (Z), the width of the second step surface (3121) is W3, satisfying: 1% ≤ W3 / W1 ≤ 10%.

17. The pole as claimed in any one of claims 1 to 3, wherein The main body (3230) includes a third sub-part (3233) and a fourth sub-part (3234). Along the third preset direction (Z), one end of the third sub-part (3233) is connected to the first flange (3210), and the other end is connected to the fourth sub-part (3234). Along the third preset direction (Z), on a plane perpendicular to the third preset direction (Z), the orthographic projection of the fourth sub-part (3234) falls within the orthographic projection range of the third sub-part (3233). A third step surface (3231) is connected between the side wall surface of the fourth sub-part (3234) and the side wall surface of the third sub-part (3233). The surface of the fourth sub-part (3234) away from the third sub-part (3233) is a second electrical connection surface (3232).

18. The pole post according to claim 17, characterized in that, On a plane perpendicular to the third preset direction (Z), the width of the third step surface (3231) is W7, satisfying: 0.3mm≤W7≤1mm; And / or, Along the third preset direction (Z), the distance between the third step surface (3231) and the second electrical connection surface (3232) is W8, which satisfies: 0.2mm≤W8≤0.7mm; And / or, Along the first preset direction (X), the width of the second electrical connection surface (3232) is W9, and on the plane perpendicular to the third preset direction (Z), the width of the third step surface (3231) is W7, satisfying: 2% ≤ W7 / W9 ≤ 20%.

19. The pole according to any of claims 1-17, characterized in that The second connecting portion (32) has a first groove (323) that is recessed from the surface (A) into the body portion (3230).

20. The pole according to claim 19, wherein Along the third preset direction (Z), the bottom surface (32301) of the first groove (323) is located on the side of the third surface (3112) away from the first surface (3111).

21. The pole as claimed in claim 19, wherein Along the third preset direction (Z), the first flange (3210) has a fourth surface (3212) that is opposite to the second surface (3211). On a plane perpendicular to the second preset direction (Y), the angle between the groove wall surface of the first groove (323) near the base part (3110) and the fourth surface (3212) is β, which satisfies: 90°≤β≤95°.

22. The pole as claimed in any one of claims 1 to 17, characterized in that The main body (3230) includes an annular sidewall (3245) and a bottom wall (3247). Along the third preset direction (Z), one end of the annular sidewall (3245) is connected to the first flange (3210), and the other end of the annular sidewall (3245) is connected to the bottom wall (3247). In the direction from the end connected to the first flange (3210) to the other end, the outer contour dimension of the annular sidewall (3245) gradually decreases or decreases in a stepwise manner.

23. The pole as claimed in any one of claims 1 to 17, wherein, Along the third preset direction (Z), the first flange (3210) has a fourth surface (3212) that is opposite to the second surface (3211). On a plane perpendicular to the second preset direction (Y), the angle between the side wall of the main body (3230) near the base (3110) and the fourth surface (3212) is α, which satisfies: 90°≤α≤95°.

24. The pole as claimed in any one of claims 1 to 17, wherein, The first connecting part (31) and the second connecting part (32) are integrally formed.

25. The pole post according to any one of claims 1-17, characterized in that, Along the first preset direction (X), the maximum width of the first electrical connection portion (3120) is W1, which satisfies: 8mm≤W1≤35mm; And / or, Along the first preset direction (X), the maximum width of the pole post is W2, which satisfies: 14mm≤W2≤80mm; And / or, Along the first preset direction (X), the maximum width of the first electrical connection part (3120) is W1, and the maximum width of the pole post is W2, satisfying: 20% ≤ W1 / W2 ≤ 60%; And / or, Along the third preset direction (Z), the distance between the first electrical connection surface (3122) of the first electrical connection part (3120) and the surface (A) is W6, which satisfies: 0.7mm≤W6≤2mm; And / or, Along the second preset direction (Y), the maximum length of the base portion (3110) of the first connecting portion (31) is W10, which satisfies: 15mm≤W10≤50mm; And / or, Along the second preset direction (Y), the maximum length of the base portion (3110) of the first connecting portion (31) is W10, and the maximum length of the first electrical connecting portion (3120) is W11, satisfying: 85% ≤ W11 / W10 ≤ 98%; And / or, Along the second preset direction (Y), the maximum length of the base portion (3110) of the first connecting portion (31) is W10, and the maximum length of the second connecting portion (32) is W12, satisfying: 80% ≤ W10 / W12 ≤ 100%; And / or, Along the first preset direction (X), the maximum width of the first electrical connection portion (3120) is W1, and the maximum width of the main body portion (3230) is W13, satisfying: 35% ≤ W13 / W1 ≤ 75%.

26. A cap assembly characterized by Includes a cover plate (10) and a pole post (30) as described in any one of claims 1 to 25; The cover plate (10) has a first through hole (11), the first connecting part (31) is disposed on one side of the cover plate (10), the third surface (3112) of the first connecting part (31) faces the cover plate (10), and at least part of the second connecting part (32) passes through the first through hole (11).

27. A battery cell, characterized by Includes a housing (200), a battery cell assembly (300), and a top cover assembly (100) as described in claim 26; The housing (200) has an opening at at least one end, the battery cell assembly (300) is housed within the housing (200), the top cover assembly (100) covers the opening, and the thickness direction of the housing (200) is consistent with the first preset direction (X); the battery cell assembly (300) includes at least two sets of battery cells (301) arranged side by side along the thickness direction of the housing (200), and at least two sets of battery cells (301) are arranged in a one-to-one correspondence with at least two second connecting portions (32), each set of battery cells (301) has an end face extending out a tab (302), and the tab (302) of each set of battery cells (301) is respectively connected to the corresponding second connecting portion (32).

28. A battery cell, characterized by: It includes a housing (200), a cell assembly (300), and a terminal (30) as described in any one of claims 1 to 25, the terminal (30) being disposed on the housing (200), and the cell assembly (300) being housed within the housing (200).

29. A battery, characterized by It includes a plurality of battery cells (1) as described in claim 27 or 28, the plurality of battery cells (1) being electrically connected by an electrical connector, the electrical connector being connected to the first connection portion (31).

30. An electrical device, comprising: A battery cell (1) as claimed in claim 27 or 28, or a battery as claimed in claim 28.

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