Pole, top cover assembly, battery monomer, battery and power utilization device

Abstract

The utility model provides a pole, a top cover assembly, a battery monomer, a battery and a power utilization device, and relates to the technical field of batteries, the pole comprises at least one first connecting part and at least two second connecting parts, along a second direction, the first connecting part has a third surface; the at least two second connecting parts are used for being connected with the tabs, each second connecting part comprises a main body part and a first flanging part, each first flanging part is connected to one end face, in the second direction, of the corresponding main body part and extends towards the corresponding first connecting part, each first flanging part is connected with the corresponding first connecting part, and each first flanging part is provided with a fourth face in the second direction; and the fourth surface and the third surface are positioned on the same side in the height direction of the post terminal, are positioned on the same plane and form a second surface. Therefore, the processing of the pole is more convenient, and the size of the pole in the width direction can be reduced.

Description

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

[0001] This utility model relates to the field of battery technology, and in particular to an electrode post, a top cover assembly, a battery cell, a battery, and an electrical device. Background Technology

[0002] In battery structure design, terminals are typically used to connect the tabs of the electrode assembly to external electrical connectors to allow current to flow in or out of the electrode assembly. Therefore, the current-carrying capacity of the terminals affects the battery's charge / discharge capability and safety performance. In related technologies, in battery cells consisting of a top cover assembly, electrode assembly, and casing, the limited width design space of the top cover assembly for relatively thin battery cells restricts the design dimensions of the terminals, resulting in weaker current-carrying capacity and hindering improvements in battery charge / discharge performance and safety. Summary of the Invention

[0003] The purpose of this application is to provide a terminal post, a top cover assembly, a battery cell, a battery, and an electrical device to solve the technical problem that the terminal post design in the prior art is too wide and not suitable for battery cells with a small thickness.

[0004] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0005] In a first aspect, this application provides an electrode post, including at least one first connecting portion and at least two second connecting portions. The at least one first connecting portion is used to connect with an electrical connector. Along a second direction, the first connecting portion has a third surface. The at least two second connecting portions are used to connect with electrode tabs. Each first connecting portion is disposed between and connected to two adjacent second connecting portions. The at least two second connecting portions are arranged at intervals along a first direction. Each second connecting portion includes a main body portion and a first flange portion. The first flange portion is connected to one end face of the main body portion along the second direction and extends toward the first connecting portion. The first flange portion is connected to the first connecting portion. Along the second direction, the first flange portion has a fourth surface. The fourth surface and the third surface are located on the same side in the height direction of the electrode post, and the fourth surface and the third surface are in the same plane and form a second surface. The first direction and the second direction intersect.

[0006] In one or more embodiments of this application, the first connecting portion includes a base portion and a first electrical connecting portion. Along the second direction, the base portion has a third surface, the first electrical connecting portion is disposed on the surface of the base portion opposite to the third surface, and the first flange portion is connected to the base portion. Along the second direction, the base portion has a first surface opposite to the third surface, and the first flange portion has a second surface opposite to the fourth surface. The first surface and the second surface are in the same plane and form a first surface.

[0007] In one or more embodiments of this application, the second connecting portion further includes a second flange portion, which is connected to one end face of the main body portion along the second direction and extends in a direction away from the base portion. The second flange portion is disposed opposite to the first flange portion along the first direction. Along the second direction, the second flange portion has a fifth surface, which is in the same plane as the first surface and forms a third surface.

[0008] Along the second direction, the second flange also has a sixth surface disposed opposite to the fifth surface. The sixth surface is in the same plane as the second surface and forms a fourth surface, wherein the third surface and the fourth surface are parallel.

[0009] In one or more embodiments of this application, the second connecting portion further includes a third flange portion and a fourth flange portion. Along a third 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.

[0010] In one or more embodiments of this application, along the first direction, the distance between the side of the first flange portion and the side of the main body portion is c, which satisfies: 0.5mm≤c≤5mm.

[0011] In one or more embodiments of this application, along the first direction, the distance between the side of the second flange and the side of the main body is d, which satisfies: 0.5mm≤d≤5mm.

[0012] In one or more embodiments of this application, 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.

[0013] In one or more embodiments of this application, along a third direction, the minimum distance between the edge side of the first electrical connection portion and the edge side of the base portion is a, satisfying: 0.2mm≤a≤5mm, wherein the third direction intersects with the first direction and the second direction respectively.

[0014] In one or more embodiments of this application, the distance between the third and fourth surfaces along the second direction is W5, which satisfies: 0.5mm≤W5≤3mm.

[0015] In one or more embodiments of this application, the second connecting portion has a first groove, which is recessed from the first surface into the body portion.

[0016] In one or more embodiments of this application, the main body includes a first sidewall and a second sidewall, which are disposed opposite to each other along a first direction. One end face of the first sidewall along a second direction is connected to a first flange, and one end face of the second sidewall along the second direction is connected to a second flange. Along the first direction, the thickness of the first sidewall is greater than the thickness of the second sidewall.

[0017] In one or more embodiments of this application, the second connecting portion includes a first metal layer and a second metal layer. The first metal layer and the second metal layer are stacked in a direction from the third surface to the fourth 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.

[0018] In one or more embodiments of this application, the first electrical connection portion includes a first sub-part and a second sub-part. Along the second direction, one end of the first sub-part is connected to the base portion, and the opposite end is connected to the second sub-part. Along the second direction, on a plane perpendicular to the second direction, the orthographic projection of the second sub-part falls within the orthographic projection range of the first sub-part. A first stepped surface is connected between the sidewall surface of the first sub-part and the sidewall surface of the second sub-part. The surface of the second sub-part away from the first sub-part is the first electrical connection surface.

[0019] In one or more embodiments of this application, the width of the first step surface on a plane perpendicular to the second direction is W3, satisfying: 0.3mm≤W3≤1mm.

[0020] In one or more embodiments of this application, along the second direction, the distance between the first step surface and the first electrical connection surface is W4, which satisfies: 0.2mm≤W4≤0.7mm.

[0021] In one or more embodiments of this application, along the second direction, the distance between the first step surface and the first electrical connection surface is W4, and the distance between the first electrical connection surface and the first surface is W6, satisfying: 15% ≤ W4 / W6 ≤ 50%.

[0022] In one or more embodiments of this application, the maximum width of the first electrical connection portion along the first direction is W1, and the width of the first step surface on the plane perpendicular to the second direction is W3, satisfying: 1% ≤ W3 / W1 ≤ 10%.

[0023] In one or more embodiments of this application, the main body includes a third sub-part and a fourth sub-part. Along the second 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 second direction, on a plane perpendicular to the second direction, the orthographic projection of the fourth sub-part falls within the orthographic projection range of the third sub-part. A second stepped surface is connected between the side wall surface of the fourth sub-part and the side wall surface of the third sub-part. The surface of the fourth sub-part away from the third sub-part is a second electrical connection surface.

[0024] In one or more embodiments of this application, the width of the second step surface on a plane perpendicular to the second direction is W7, satisfying: 0.3mm≤W7≤1mm.

[0025] In one or more embodiments of this application, along the second direction, the distance between the second step surface and the second electrical connection surface is W8, which satisfies: 0.2mm≤W8≤0.7mm.

[0026] In one or more embodiments of this application, the width of the second electrical connection surface is W9 along the first direction, and the width of the second step surface is W7 on the plane perpendicular to the second direction, satisfying: 2% ≤ W7 / W9 ≤ 20%.

[0027] In one or more embodiments of this application, the maximum width of the first electrical connection portion along the first direction is W1, which satisfies: 8mm≤W1≤35mm.

[0028] In one or more embodiments of this application, along the first direction, the maximum width of the pole post is W2, which satisfies: 14mm≤W2≤80mm.

[0029] In one or more embodiments of this application, along the first 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%.

[0030] In one or more embodiments of this application, along the second direction, the distance between the first electrical connection surface of the first electrical connection portion and the first surface is W6, which satisfies: 0.7mm≤W6≤2mm.

[0031] In one or more embodiments of this application, along a third direction, the maximum length of the base portion of the first connecting portion is W10, satisfying: 15mm≤W10≤50mm.

[0032] In one or more embodiments of this application, along a third 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%.

[0033] In one or more embodiments of this application, along a third 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%.

[0034] In one or more embodiments of this application, along the first direction, the maximum width of the first electrical connection portion is W1, and the maximum width of the main body portion is W13, satisfying: 35% ≤ W13 / W1 ≤ 75%.

[0035] In one or more embodiments of this application, on a plane perpendicular to the third direction, the angle between the side wall of the main body near the base and the fourth surface is α, satisfying: 90°≤α≤95°.

[0036] In one or more embodiments of this application, the second connecting portion has a first groove, which is recessed from the first surface into the body portion. On a plane perpendicular to the third direction, the angle between the groove wall surface of the first groove near the base portion and the fourth surface is β, which satisfies: 90°≤β≤95°.

[0037] In one or more embodiments of this application, the fourth surface of the first flange portion is connected to the side wall surface of the main body portion by a first arc segment.

[0038] In one or more embodiments of this application, the second connecting portion includes a second flange portion, which extends in a direction away from the base portion. The second flange portion is disposed opposite to the first flange portion along a first direction, and the sixth surface of the second flange portion is connected to the side wall surface of the main body portion through a second arc segment.

[0039] In one or more embodiments of this application, the second connecting portion has a first groove, which is recessed from the first surface into the main body portion, and the groove wall surface and the groove bottom surface are connected by a third arc segment.

[0040] In one or more embodiments of this application, the second connecting portion has a first groove, which is recessed from the first surface into the main body portion, and the groove wall surface of the first groove is connected to the second surface of the first flange portion by a fourth arc segment.

[0041] In one or more embodiments of this application, the second connecting portion includes a second flange portion, the second connecting portion has a first groove, and the groove wall surface of the first groove is connected to the fifth surface of the second flange portion by a fifth arc segment.

[0042] In one or more embodiments of this application, it further includes: a fusible portion connected between the first connecting portion and the second connecting portion, the fusible portion having a seventh surface and an eighth surface disposed opposite to each other along a second direction, wherein the seventh surface is in the same plane as the first surface; and / or, the eighth surface is in the same plane as the second surface.

[0043] In a second aspect, this application provides a top cover assembly, including: a top cover sheet and a pole as described in any of the first aspects; the top cover sheet has a first through hole along its thickness direction, a first connecting portion is disposed on one side of the top cover sheet, and a second connecting portion is at least partially inserted into the first through hole, the second direction being the thickness direction of the top cover sheet.

[0044] Thirdly, this application provides a top cover assembly, including: a top cover sheet and an electrode post, wherein the top cover sheet has a first through hole along its thickness direction, and the electrode post includes:

[0045] At least one first connecting portion for connection with an electrical connector, and the first connecting portion having a third surface along a second direction;

[0046] At least two second connecting portions are provided for connecting to the electrode tabs. The second connecting portions are at least partially inserted into the first through hole. Each first connecting portion is provided between two adjacent second connecting portions and is connected to the two adjacent second connecting portions. The at least two second connecting portions are arranged at intervals along a first direction. Each second connecting portion includes a main body portion and a first flange portion. The first flange portion is connected to one end face of the main body portion along a second direction and extends toward the first connecting portion. The first flange portion is connected to the first connecting portion. Along the second direction, the first flange portion has a fourth surface. The fourth surface and the third surface are located on the same side in the height direction of the electrode post and are in the same plane, forming a second surface. The first direction and the second direction intersect. The second direction is the thickness direction of the top cover plate.

[0047] In one or more embodiments of this application, the first connecting portion includes a base portion and a first electrical connecting portion. Along the second direction, the base portion has a third surface, the first electrical connecting portion is disposed on the surface of the base portion opposite to the third surface, and the first flange portion is connected to the base portion. Along the second direction, the base portion has a first surface opposite to the third surface, and the first flange portion has a second surface opposite to the fourth surface. The first surface and the second surface are in the same plane and form a first surface.

[0048] In one or more embodiments of this application, the second connecting portion further includes a second flange portion, which is connected to one end face of the main body portion along the second direction and extends in a direction away from the base portion. The second flange portion is disposed opposite to the first flange portion along the first direction. Along the second direction, the second flange portion has a fifth surface, which is located on the same side as the first surface in the pole height direction. The fifth surface and the first surface are in the same plane and form a third surface.

[0049] Along the second direction, the second flange also has a sixth surface disposed opposite to the fifth surface. The sixth surface is in the same plane as the second surface and forms a fourth surface, wherein the third surface and the fourth surface are parallel.

[0050] Fourthly, this application provides a battery cell, including: a housing, an electrode assembly, and a top cover assembly according to any one of the second or third aspects, wherein the housing has an opening; the electrode assembly has tabs and is received within the housing; and the top cover assembly covers the opening of the housing.

[0051] Fifthly, this application provides a battery, including the battery cell of the fourth aspect.

[0052] Sixthly, this application provides an electrical device, including a battery cell as described in the fourth aspect, or a battery as described in the fifth aspect.

[0053] Based on the above technical solutions, the terminal post, top cover assembly, battery cell, battery, and power device provided in this application have at least the following beneficial technical effects:

[0054] The electrode post provided in this application embodiment has at least one first connecting part and at least two second connecting parts. By connecting the first flange of the second connecting part to the base part of the first connecting part, and the second surface of the first flange and the first surface of the base part forming a first surface on the same plane, on the one hand, the electrode post can be processed more conveniently by stamping, and on the other hand, while ensuring that the first connecting part and the second connecting part have the required welding area, the dimension in the width direction of the electrode post can be reduced, so that it can be applied to battery cells with limited space in the top cover assembly design without affecting the performance of the battery. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0056] Figure 1 is a three-dimensional structural diagram of a battery cell provided in an embodiment of this application.

[0057] Figure 2 is a schematic diagram of the front view structure of a battery cell provided in an embodiment of this application.

[0058] Figure 3 is a cross-sectional view of AA in Figure 2.

[0059] Figure 4 is a cross-sectional view of BB in Figure 2.

[0060] Figure 5 is a front view of the top cover assembly provided in an embodiment of this application.

[0061] Figure 6 is a cross-sectional view of AA in Figure 5.

[0062] Figure 7 is a cross-sectional view of BB in Figure 5.

[0063] Figure 8 is an exploded disassembly diagram of the top cover assembly provided in an embodiment of this application.

[0064] Figure 9 is a three-dimensional structural diagram of the pole post in the top cover assembly provided in the embodiment of this application.

[0065] Figure 10 is a side view of the pole post in the top cover assembly provided in an embodiment of this application.

[0066] Figure 11 is another side view of the pole post in the top cover assembly provided in the embodiment of this application.

[0067] Figure 12 is a top view of the pole post in the top cover assembly provided in an embodiment of this application.

[0068] Figure 13 is a CC cross-sectional view of Figure 12.

[0069] Figure 14 is a three-dimensional structural diagram of the pole post in the top cover assembly provided in another embodiment of this application.

[0070] Figure 15 is a side view of the pole post in the top cover assembly provided in another embodiment of this application.

[0071] Figure 16 is a top view of the pole in the top cover assembly provided in another embodiment of this application.

[0072] Figure 17 is a cross-sectional view of DD in Figure 16.

[0073] Figure 18 is a three-dimensional structural diagram of the pole post in the top cover assembly provided in another embodiment of this application.

[0074] Figure 19 is a side view of the pole post in the top cover assembly provided in another embodiment of this application.

[0075] Figure 20 is another side view of the pole in the top cover assembly provided in another embodiment of this application.

[0076] Figure 21 is a top view of the pole post in the top cover assembly provided in another embodiment of this application.

[0077] Figure 22 is a cross-sectional view of AA in Figure 21.

[0078] Figure 23 is a three-dimensional structural diagram of the pole post in the top cover assembly provided in another embodiment of this application.

[0079] Figure 24 is a side view of the pole post in the top cover assembly provided in another embodiment of this application.

[0080] Figure 25 is a top view of the pole post in the top cover assembly provided in another embodiment of this application.

[0081] Figure 26 is a cross-sectional view of BB in Figure 25.

[0082] In the figure: 1-First insulating component; 2-Electrode post; 3-Top cover plate; 4-Second insulating component; 5-Housing; 6-Electrode assembly; 7-Pressure relief mechanism; 10-First connecting part; 20-Second connecting part; 21-First groove; 22-First metal layer; 23-Second metal layer; 30-Fuse part; 31-First through hole; 32-Second groove; 41-Second through hole; 61-Electrode tab; 71-Protective layer; 100-First insulating part; 200-Second insulating part; 300-Third insulating part; 110-Base part; 120-First electrical connection part; 121-First stepped surface; 111-First surface; 112-Third surface; 122-First electrical connection surface; 123-First sub-part; 124-Second sub-part; 210 - First flange; 211-Second surface; 212-Fourth surface; 220-Second flange; 221-Fifth surface; 222-Sixth surface; 230-Main body; 231-Second stepped surface; 232-Second electrical connection surface; 233-Third sub-part; 234-Fourth sub-part; 240-Second electrical connection; 250-First arc segment; 260-Second arc segment; 270-Third arc segment; 280-Fourth arc segment; 290-Fifth arc segment; 2201-Third flange; 2202-Fourth flange; 2121-Second side wall; 2122-Third side wall; 2123-First side wall; 2124-Fourth side wall; 2125-Groove bottom surface; 301-Seventh surface; 302-Eighth surface. Detailed Implementation

[0083] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0084] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0085] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0086] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0087] In related technologies, the electrode post has five parts along its width direction: a first connecting part in the middle, two transition parts, and two second connecting parts on both sides of the first connecting part. The first connecting part is connected to the second connecting parts on both sides through the transition parts. The first connecting part is used for welding with electrical connectors, and the second connecting parts are used for welding with the tabs of the electrode assembly. However, in related technologies, the upper surface of the second connecting part facing the outside of the housing is not on the same plane as the upper surface of the first connecting part facing the outside of the housing. Usually, the upper surface of the first connecting part facing the outside of the housing is higher than the upper surface of the second connecting part facing the outside of the housing. This results in the transition part connecting the two being inclined, and it also occupies space in the width direction of the electrode post, increasing the processing difficulty of the electrode post and making the width of the electrode post larger.

[0088] Based on the above considerations, and to address the technical problems of existing electrode post designs being too wide, difficult to manufacture, and unsuitable for thinner battery cells, this application provides an electrical device, a battery, a battery cell, a top cover assembly, and electrode posts.

[0089] The electrical devices disclosed in this application can be 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 fixed 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.

[0090] This application describes an electrical device using a vehicle as an example. The vehicle can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery is installed inside the vehicle, and the battery can be located at the bottom, front, or rear of the vehicle. The battery can be used to power the vehicle; for example, it can serve as the vehicle's operating power source. The vehicle may also include a controller and a motor. The controller controls the battery to supply power to the motor, for example, to meet the power needs of starting, navigation, and driving the vehicle. The battery can not only serve as the vehicle's operating power source but also as its driving power source, replacing or partially replacing gasoline or natural gas to provide driving power to the vehicle.

[0091] As one embodiment of the battery, 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. The 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 the multiple 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.

[0092] 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 plugging in 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 plugging in each other, which will not be elaborated further here.

[0093] The aforementioned battery cell can be a secondary battery or a primary battery, and can also be a lithium-ion battery, a sodium-ion battery, or a magnesium-ion battery. Its external outline can be cylindrical, flat, cuboid, or other shapes, but is not limited to these. Specifically, in this embodiment, the aforementioned battery cell is a lithium-ion square battery.

[0094] As one embodiment of a battery cell, please refer to Figures 1, 2, 3, and 4. A battery cell refers to the smallest unit that makes up a battery. The battery cell includes a housing 5, an electrode assembly 6, a top cover assembly, and other functional components. At least one end of the housing 5 has an opening, and the top cover assembly covers the opening of the housing 5 to isolate the internal environment of the battery cell from the external environment. The housing 5 has a receiving cavity inside to accommodate the electrode assembly 6. The housing 5 is a component used to cooperate with the top cover assembly to form the internal environment of the battery cell, wherein the formed internal environment can accommodate the electrode assembly 6, electrolyte, and other components. The housing 5 and the top cover assembly can be independent components. An opening can be provided on the housing 5, and the internal environment of the battery cell is formed by the top cover assembly covering the opening. The housing 5 can have various shapes and sizes, such as cylindrical, cuboid, hexagonal prism, etc. Specifically, the shape of the housing 5 can be determined according to the specific shape and size of the electrode assembly 6. The shell 5 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. This application embodiment does not impose any special restrictions on this.

[0095] As one embodiment of the electrode assembly, the electrode assembly 6 is a component in the battery cell that undergoes an electrochemical reaction with the electrolyte. The housing 5 may contain one or more electrode assemblies 6. The electrode assembly 6 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. During the charging and discharging process of the battery cell, active ions (e.g., lithium ions) repeatedly insert and extract between the positive and negative electrode sheets. The separator, positioned between the positive and negative electrode sheets, can reduce short circuits between the positive and negative electrodes while allowing active ions to pass through. This application does not impose any particular limitation on the type of separator; any known porous separator with good chemical and mechanical stability can be selected. The positive electrode sheet may include a positive current collector and positive active material layers coated on opposite sides of the positive current collector. The negative electrode sheet may include a negative current collector and negative active material layers coated on opposite sides of the negative current collector. The portions of the positive and negative electrode plates containing active material constitute the main body of the electrode assembly, while the portions of the positive and negative electrode plates without active material each constitute a tab. The positive and negative tabs can be located together at one end of the main body or at opposite ends. The electrode assembly 6 is covered with an insulating film to reduce the risk of short circuits.

[0096] In some embodiments, each electrode assembly 6 extends a positive electrode tab and a negative electrode tab toward the end face of the top cover assembly, respectively. During the charging and discharging process of the battery, the positive electrode active material and the negative electrode active material react with the electrolyte, and the electrode tabs are connected to the terminal post 2 to form a current loop.

[0097] In this embodiment, as shown in Figures 3 and 4, the housing 5 includes two sets of electrode assemblies 6, each set containing one electrode assembly 6. The two sets of electrode assemblies 6 are arranged side-by-side along the thickness direction of the housing 5. The two sets of positive electrode tabs of the two sets of electrode assemblies 6 are arranged opposite each other as positive electrodes, and the two sets of negative electrode tabs of the two sets of electrode assemblies 6 are arranged opposite each other as negative electrodes. The two sets of positive electrode tabs and the two sets of negative electrode tabs are spaced apart along the length direction of the housing 5. In other embodiments, the housing 5 may also include at least two sets of electrode assemblies 6. Each set of electrode assemblies 6 may contain one electrode assembly 6 or multiple electrode assemblies 6, which is not limited here. When each set of electrode assemblies 6 includes multiple electrode assemblies 6, the positive electrode tabs of each electrode assembly 6 are brought together to form one set of positive electrode tabs, and the negative electrode tabs are brought together to form one set of negative electrode tabs.

[0098] It should be noted that the length direction of the housing 5 is also the length direction of the top cover assembly or the length direction of the electrode assembly 6, the thickness direction of the housing 5 is also the width direction of the top cover assembly or the thickness direction of the electrode assembly 6, and the height direction of the housing 5 is also the height direction of the electrode assembly 6 or the thickness direction of the top cover sheet 3.

[0099] Before the electrode assembly 6 is installed into the housing 5, the electrode tab 61 of the electrode assembly 6 is first assembled with the top cover assembly, for example, the electrode post 2 of the top cover assembly is welded to the electrode tab 61 of the electrode assembly 6, and then the electrode assembly 6 is installed into the housing 5.

[0100] As one embodiment of the top cover assembly, referring to Figures 3 to 8, the top cover assembly includes a top cover sheet 3, which covers the opening of the housing 5. In any case, the shape of the top cover sheet 3 can be adapted to the shape of the housing 5 to fit the opening of the housing 5. The top cover sheet 3 can be made of a material with a certain hardness and strength (such as aluminum alloy or aluminum), so that the top cover sheet 3 is not easily deformed under pressure or impact, enabling the battery cell to have higher structural strength and improving safety performance. The material of the top cover sheet 3 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.

[0101] Referring to Figure 8, the top cover plate 3 has a first through hole 31 extending through its thickness direction. The first through hole 31 is used to install functional components, such as the pole post 2. In this embodiment, a second groove 32 is provided on the surface of the top cover plate 3 facing the outside of the housing. The second groove 32 is recessed from the surface of the top cover plate 3 facing the outside of the housing towards the surface of the top cover plate 3 facing the inside of the housing. The first through hole 31 penetrates the bottom wall of the groove of the second groove 32 along the thickness direction of the top cover plate 3. For example, in this embodiment, two first through holes 31 are disposed in the second groove 32, with a gap between the hole wall of the first through hole 31 and the groove side wall of the second groove 32, that is, the hole wall of the first through hole 31 and the groove side wall of the second groove 32 are not aligned. When the terminal post 2 is installed on the top cover plate 3, the setting of the second groove 32 reduces the distance between the first electrical connection surface 122 of the terminal post 2 facing the outside of the housing and the upper surface of the top cover plate 3, thereby improving the space utilization of the battery; at the same time, the setting of the second groove 32 allows the second connection part 20 of the terminal post 2 to be closer to the inside of the housing, which can reduce the height of the second connection part 20, thereby reducing the height of the terminal post 2 and reducing the processing difficulty of the terminal post 2.

[0102] As shown in Figure 8, the top cover plate 3 may be provided with functional components such as pole post 2, first insulating component 1, second insulating component 4, and pressure relief mechanism 7. The top cover plate 3 and the functional components such as pole post 2, first insulating component 1, second insulating component 4 and pressure relief mechanism 7 provided on the top cover plate 3 together constitute the top cover assembly.

[0103] The terminal 2 can be electrically connected to the electrode assembly 6 for outputting or inputting electrical energy from the battery cell. The terminal 2 includes a positive terminal and a negative terminal. The positive terminal is connected to the positive electrode tab, thereby introducing the positive current of the battery cell into the interior of the housing 5 or leading it out of the housing 5. The negative terminal is connected to the negative electrode tab, thereby introducing the negative current of the battery cell into the interior of the housing 5 or leading it out of the housing 5. The positive and negative terminals of adjacent battery cells can be electrically connected in series, parallel, or in a mixed manner using electrical connectors.

[0104] It should be noted that the "terminal 2" mentioned in this application can be either a positive terminal or a negative terminal (unless otherwise specified). The "tab 61" mentioned in this application can be either a positive or a negative tab (unless otherwise specified), as long as the tab connected to the positive terminal is the positive tab and the tab connected to the negative terminal is the negative tab.

[0105] It should be noted that the first direction X, the second direction Y, and the third direction Z described in this application intersect each other. That is, the first direction X intersects the second direction Y, the first direction X intersects the third direction Z, and the second direction Y intersects the third direction Z. In some embodiments, the first direction X, the second direction Y, and the third direction Z are mutually perpendicular. The first direction X described in this application can be the width direction of the electrode post 2, that is, the width direction of the top cover plate 3, that is, the thickness direction of the electrode assembly 6 or the housing 5. The second direction Y can be the height direction of the electrode post 2, that is, the thickness direction of the top cover plate 3, that is, the height direction of the electrode assembly 6 or the housing 5. The third direction Z can be the length direction of the electrode post 2, that is, the length direction of the top cover plate 3, that is, the length direction of the electrode assembly 6 or the housing 5.

[0106] Specifically, referring to Figures 6, 7, and 8, the electrode post 2 includes at least one first connecting portion 10 and at least two second connecting portions 20. The first connecting portion 10 is used to connect with an electrical connector, and the second connecting portions 20 are used to connect with the tabs 61 of the electrode assembly 6. The first connecting portion 10 is located on the side of the top cover plate 3 facing the outside of the housing so that the first connecting portion 10 can connect with the electrical connector. At least a portion of the second connecting portion 20 passes through the first through hole 31 of the top cover plate 3 so that the second connecting portion 20 can connect with the tabs 61. Each first connecting portion 10 is located between two adjacent second connecting portions 20 and is connected to two adjacent second connecting portions 20. At least two second connecting portions 20 are arranged at intervals along a first direction X, that is, at least two second connecting portions 20 are arranged at intervals along the width direction of the electrode post 2.

[0107] It is understood that the number of second connecting parts 20 is not limited to two, but can also be three, four or more. The number of second connecting parts 20 can correspond to the number of electrode assemblies 6 inside the housing 5, so that each second connecting part 20 is connected to a set of electrode tabs 61.

[0108] When the number of electrode assemblies 6 disposed within the housing 5 is N, the number of second connecting parts 20 is also set to N, where N is an integer greater than 1. The N second connecting parts 20 are spaced apart along the first direction X and connected to the first connecting parts 10. The N second connecting parts 20 pass through the first through hole 31 and are correspondingly connected to the tabs 61 of each group of electrode assemblies 6.

[0109] The second connecting part 20 of this application embodiment can be directly welded to the tab 61. Therefore, at least a portion of the second connecting part 20 passes through the first through hole 31 and extends into the housing 5 to be directly connected to the tab 61. No adapter structure is required, which reduces the use of parts, lowers the cost of the battery cell, and at the same time reduces the internal resistance of the battery cell and improves the energy density of the battery cell.

[0110] In some other embodiments, the number of first connecting portions 10 is not limited to one, but can be two or more. The number of first connecting portions 10 is related to the number of second connecting portions 20. A first connecting portion 10 is provided between two adjacent second connecting portions 20. For example, when the number of second connecting portions 20 is 2, the number of first connecting portions 10 is 1. When the number of second connecting portions 20 is 3, the number of first connecting portions 10 is 2. When the number of second connecting portions 20 is 4, the number of first connecting portions 10 is 3, and so on. The second connecting portions 20 and the first connecting portions 10 are arranged alternately along the first direction X. For example, when the number of second connecting portions 20 is 3 and the number of first connecting portions 10 is 2, the pole post 2 along the first direction X includes a second connecting portion 20, a first connecting portion 10, a second connecting portion 20, a first connecting portion 10, and a second connecting portion 20 connected in sequence.

[0111] This embodiment of the application takes the case of two sets of electrode assemblies 6 arranged inside the housing 5, with each set of electrode assemblies 6 containing one electrode assembly 6 as an example. Since two electrode assemblies 6 can be arranged along the first direction X inside the housing 5, the two electrode assemblies 6 can extend positive and negative electrode tabs from the same end. The two positive electrode tabs 61 are arranged at intervals along the first direction X, and the two negative electrode tabs 61 are arranged at intervals along the first direction X. The two sets of positive electrode tabs and the two sets of negative electrode tabs are arranged at intervals along the third direction Z. Therefore, each pole post 2 is provided with two second connecting parts 20 and one first connecting part 10. The two second connecting parts 20 are arranged at intervals along the first direction X so as to directly connect with each set of electrode tabs 61. One first connecting part 10 is connected to the adjacent second connecting parts 20 on both sides along the first direction X so that the current drawn from the two second connecting parts 20 is output through one first connecting part 10. Compared with each second connecting part 20 corresponding to one first connecting part 10, the size and space occupied by the pole post 2 can be greatly reduced, saving materials and costs, and also facilitating processing.

[0112] The top cover plate 3 may have a first through hole 31 corresponding to each second connecting part 20, so that each second connecting part 20 passes through the first through hole 31 and is connected to the corresponding electrode tab 61. It is understood that the number of first through holes 31 may be the same as the number of second connecting parts 20. In other embodiments, the size of the first through hole 31 may also allow two second connecting parts 20 to pass through.

[0113] In this embodiment of the application, as shown in Figure 11 or Figure 20, the maximum width of the electrode post 2 along the first 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. Specifically, 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 2 can ensure that the first connecting portion 10 and the two second connecting portions 20 have a welding area that meets the requirements, and it can be applied to battery cells of various thicknesses.

[0114] As one embodiment of the pole post 2, referring to Figures 9, 10, 14, 15, 18, 19, 23, and 24, the first connecting portion 10 of the pole post 2 includes a base portion 110 and a first electrical connection portion 120, which are integrally formed. Along the second direction Y, the base portion 110 has a first surface 111 and a third surface 112 opposite to the first surface 111. The first surface 111 can be the surface of the base portion 110 facing the outside of the housing, and the third surface 112 can be the surface of the base portion 110 facing the inside of the housing. The first electrical connection portion 120 is disposed on the surface of the base portion 110 having the first surface 111, that is, on the surface of the base portion 110 facing away from the third surface 112. It is understood that the first electrical connection portion 120 and the base portion 110 are stacked along the height direction of the pole post 2, and the cross-sectional area of ​​the base portion 110 is larger than the cross-sectional area of ​​the first electrical connection portion 120. The first electrical connection portion 120 is used to connect with an electrical connector. The base portion 110 can be connected with the second connection portion 20.

[0115] As shown in Figure 11 or Figure 20, along the first direction X, the relationship between the maximum width W1 of the first electrical connection portion 120 and the maximum width W2 of the pole post 2 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. Specifically, 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 120 and the welding surface width of the second connection portion 20 can both meet the overcurrent requirements. When W1 / W2 is less than 30%, the width of the first electrical connection 120 is smaller, resulting in a smaller welding area and causing the welding point of the first electrical connection 120 to become a current bottleneck. When W1 / W2 is greater than 50%, the width of the first electrical connection 120 is larger, resulting in a smaller welding surface width of the second connection 20 and causing the welding point of the second connection 20 to become a current bottleneck.

[0116] Furthermore, as shown in Figure 11 or Figure 20, along the first direction X, the maximum width of the first electrical connection portion 120 is W1, satisfying: 8mm ≤ W1 ≤ 35mm. For example, W1 can be located within multiple intervals such as 8mm ≤ W1 ≤ 25mm, 8mm ≤ W1 ≤ 15mm, etc. Specifically, 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 120 can have a welding surface width that meets the requirements.

[0117] As shown in Figure 12, 16, or 21, along the third direction Z, the relationship between the maximum length W11 of the first electrical connection portion 120 and the maximum length W10 of the base portion 110 of the first connection portion 10 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%. Specifically, 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 length of the first electrical connection portion 120 and the length of the base portion 110 are set within a suitable range, which makes it easier for the upper and lower dies and the edges of the base portion 110 to have sufficient contact area when the pole post 2 is punched out of the outer contour, thereby reducing the processing difficulty of the pole post 2 and reducing the burrs generated on the outer edge of the pole post 2; at the same time, it provides a suitable width for the first insulating member 1 covering the first electrical connection portion 120 in the circumferential direction, and avoids the first insulating member 1 from falling off from the pole post 2 due to insufficient covering width.

[0118] Furthermore, as shown in Figure 12, 16, or 21, along the third direction Z, the maximum length of the base portion 110 of the first connecting portion 10 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. Specifically, 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 10 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 10 will be shorter, resulting in a smaller current-carrying area and a lower charge / discharge rate of the battery cell. When W10 is greater than 50mm, the welding area of ​​the first connection part 10 will be too long, increasing the cost and weight of the terminal post.

[0119] Along the third direction Z, as shown in Figures 12, 16, 19, or 24, the minimum distance 'a' between the edge of the first electrical connection portion 120 and the edge of the base portion 110 satisfies: 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 110 and the first electrical connection portion 120. When 'a' is less than 0.2mm, the edge of the first electrical connection portion 120 is closer to the edge of the base portion 110, causing the first stepped surface 121 to collapse. When 'a' is greater than 5mm, the welding area of ​​the first electrical connection surface 122 decreases, affecting the current carrying capacity of the electrode.

[0120] Referring to Figures 9 and 10, or Figures 14 and 15, or Figures 18 and 19, or Figures 23 and 24, the first electrical connection portion 120 includes a first sub-portion 123 and a second sub-portion 124. Along the second direction Y, one end of the first sub-portion 123 is connected to the base portion 110, and the opposite end is connected to the second sub-portion 124. It is understood that the second sub-portion 124 and the first sub-portion 123 are stacked along the second direction Y. Along the second direction Y, the orthographic projection of the second sub-portion 124 onto the top cover plate 3 falls within the orthographic projection range of the first sub-portion 123 onto the top cover plate 3; that is, the cross-sectional area of ​​the second sub-portion 124 is smaller than the cross-sectional area of ​​the first sub-portion 123. In some embodiments, the upper or lower surface of the top cover plate 3 is a plane perpendicular to the second direction Y. Thus, a first stepped surface 121 connects the sidewalls of the first sub-portion 123 and the second sub-portion 124. The surface of the second sub-part 124 away from the first sub-part 123 is designated as the first electrical connection surface 122, 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 122 can extend from the first electrical connection surface 122 into the interior of the first electrical connection portion 120. Both the first stepped surface 121 and the first electrical connection surface 122 are located on the side of the first electrical connection portion 120 away from the first surface 111. The first electrical connection surface 122 protrudes from the first stepped surface 121 along the second direction Y, meaning that the first stepped surface 121 is located closer to the base portion 110 than the first electrical connection surface 122, and the first stepped surface 121 surrounds the edge of the first electrical connection portion 120. The arrangement of the first stepped surface 121 ensures that there is a distance between the edge of the first insulating member 1 covering the outside of the base portion 110 and the first electrical connection surface 122, preventing interference with the first electrical connection surface 122 and thus affecting the welding quality between the first electrical connection surface 122 and the electrical connector. Understandably, during the injection molding of the first insulating component 1, the provision of the first stepped surface 121 can prevent plastic material from overflowing onto the first electrical connection surface 122 and affecting the welding quality.

[0121] Since the first step surface 121 is formed around the sidewall of the second sub-part 124, in some embodiments, the first step surface 121 is located on a plane perpendicular to the second direction Y. Thus, as shown in FIG11 or FIG20, on the plane perpendicular to the second direction Y, that is, on the plane composed of the first direction X and the third direction Y, including both the first direction X and the third direction Y, the width of the first step surface 121 is W3, satisfying: 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. Specifically, 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 2 is approximately 0.15 mm, setting the width W3 of the first step surface 121 within the aforementioned range provides a certain pressing surface for the welding fixture, enabling welding between the first electrical connection surface 122 and the electrical connector, while ensuring that the first electrical connection surface 122 has sufficient welding area. It also provides sufficient connection surface width for the first insulating member 1 pressed onto the first surface 111 of the base portion 110, allowing the first insulating member 1 to be stably connected to the first connecting portion 10. Of course, in some other embodiments, the first step surface 121 may also have an angle with the plane perpendicular to the second direction Y, i.e., the first step surface 121 is inclined. In this case, the width W3 of the first step surface 121 on the plane perpendicular to the second direction Y is the width of the orthographic projection of the first step surface 121 on the plane perpendicular to the second direction Y.

[0122] As shown in Figure 11 or Figure 20, along the second direction Y, the distance between the first step surface 121 and the first electrical connection surface 122 is W4, satisfying: 0.2mm ≤ W4 ≤ 0.7mm. For example, W4 can be located within the range of 0.2mm ≤ W4 ≤ 0.5mm. Specifically, 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 first step surface 121 and the first electrical connection surface 122 within the above range makes it less likely that the height of the electrode post 2 will be too high, thereby improving the space utilization of the battery and reducing the molding difficulty of the electrode post 2. It also prevents W4 from being too small, so as to avoid the plastic material overflowing onto the first electrical connection surface 122 and affecting the welding quality.

[0123] The relationship between the width W3 of the first stepped surface 121 and the maximum width W1 of the first electrical connection portion 120 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. Specifically, 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 setting, a certain pressing surface can be provided for the welding fixture to realize the welding between the first electrical connection surface 122 and the electrical connector, while ensuring that the first electrical connection surface 122 has sufficient welding area. It can be understood that when the first electrical connection portion 120 does not have the first stepped surface 121, the maximum width W1 of the first electrical connection portion 120 is equal to the maximum width of the first electrical connection surface 122, that is, the entire surface of the first electrical connection portion 120 away from the base portion 110 is used as the first electrical connection surface 122. In some embodiments, although the cross-sectional area of ​​the base portion 110 is larger than the cross-sectional area of ​​the first electrical connection portion 120, the maximum width of the base portion 110 in the first direction X can be equal to the maximum width W1 of the first electrical connection portion 120.

[0124] As shown in Figure 11 or Figure 20, along the second direction Y, the distance between the first step surface 121 and the first electrical connection surface 122 is W4, and the distance between the first electrical connection surface 122 and the first surface 111 is W6, satisfying: 15% ≤ W4 / W6 ≤ 50%. For example, W4 / W6 can be located in multiple intervals such as 15% ≤ W4 / W6 ≤ 40%, 15% ≤ W4 / W6 ≤ 30%, 15% ≤ W4 / W6 ≤ 25%, 15% ≤ W4 / W6 ≤ 20%, etc. Specifically, 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 2 is not too high, reducing the molding difficulty of the electrode post 2 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 122 and affecting the welding quality.

[0125] As shown in Figure 11 or Figure 20, along the second direction Y, the distance between the first electrical connection surface 122 and the first surface 111 of the first electrical connection portion 120 is W6, satisfying: 0.7mm≤W6≤2mm. For example, W6 can be located within multiple intervals such as 0.7mm≤W6≤1.5mm, 0.7mm≤W6≤1.2mm, etc. Specifically, 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 1 covering the first electrical connection portion 120 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 1 covering that area will be too thin, making it easy to be damaged and causing the terminal post 2 to be exposed. When W6 is greater than 2mm, the thickness of the first insulating member 1 covering that area will be too thick, reducing the space utilization rate of the battery.

[0126] As shown in Figures 12, 16, or 21, along the third direction Z, the relationship between the maximum length W12 of the second connecting portion 20 and the maximum length W10 of the base portion 110 of the first connecting portion 10 satisfies: 80% ≤ W10 / W12 ≤ 100%. For example, W10 / W12 can be within multiple intervals such as 80% ≤ W10 / W12 ≤ 95%, 80% ≤ W10 / W12 ≤ 90%, 80% ≤ W10 / W12 ≤ 85%, etc. Specifically, 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 is understood that the maximum length of the base portion 110 can be equal to or less than the maximum length of the second connecting portion 20. The above configuration allows for the reduction of material usage and the decrease in weight and cost of the pole post 2 while ensuring the welding area of ​​the second connecting part 20 and the first connecting part 10.

[0127] As one embodiment of the pole, please refer to Figures 9, 14, 18 or 23. The second connection portion 20 of the pole 2 includes a main body portion 230. As one embodiment of the main body portion 230 of the pole, a second electrical connection portion 240 is formed at one end of the main body portion 230 facing the interior of the housing along the second direction Y.

[0128] As shown in Figures 9 to 11, or Figures 14, 15, 18, 19, 23, and 24, the main body 230 includes a third sub-part 233 and a fourth sub-part 234, which are stacked along the second direction Y. Along the second direction Y, on a plane perpendicular to the second direction Y, the orthographic projection of the fourth sub-part 234 falls within the orthographic projection range of the third sub-part 233; that is, the cross-sectional area of ​​the fourth sub-part 234 is smaller than the cross-sectional area of ​​the third sub-part 233. A second stepped surface 231 connects the sidewall of the fourth sub-part 234 and the sidewall of the third sub-part 233, and the end surface of the fourth sub-part 234 away from the third sub-part 233 is a second electrical connection surface 232. Along the second direction Y, i.e., the height direction of the electrode post 2, the second stepped surface 231 and the second electrical connection surface 232 are located on the side of the second connection portion 20 facing the interior of the housing. The second electrical connection surface 232 protrudes from the second stepped surface 231 along the second direction Y, meaning that the second electrical connection surface 232 is located closer to the electrode assembly 6 than the second stepped surface 231, and the second stepped surface 231 is located around the edge side of the second electrical connection portion 240. The second electrical connection surface 232 is used to connect with the tab 61. The solder joint depth of the tab 61 and the second electrical connection surface 232 extends from the tab 61 through the second electrical connection surface 232 toward the interior of the main body portion 230. The protrusion of the second electrical connection surface 232 from the second stepped surface 231 facilitates direct welding of the tab 61 to the second electrical connection surface 232, avoiding interference and damage to the tab 61 from other components, and improving the safety of the battery cell.

[0129] Since the second step surface 231 is formed around the sidewall of the fourth sub-part 234, in some embodiments, the second step surface 231 is located on a plane perpendicular to the second direction Y. Thus, as shown in FIG11 or FIG20, on the plane perpendicular to the second direction Y, that is, on the plane composed of the first direction X and the third direction Y, including both the first direction X and the third direction Y, the width of the second step surface 231 is W7, satisfying: 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. Specifically, 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 2 is approximately 0.15 mm, setting the width W7 of the second step surface 231 within the aforementioned range provides a certain pressing surface for the welding fixture, enabling welding between the second electrical connection surface 232 and the electrode tab, while ensuring that the second electrical connection surface 232 has sufficient welding area. Of course, in some other embodiments, the second step surface 231 may also have an angle with the plane perpendicular to the second direction Y, i.e., the second step surface 231 is inclined. In this case, the width W7 of the second step surface 231 on the plane perpendicular to the second direction Y is the width of the orthographic projection of the second step surface 231 onto the plane perpendicular to the second direction Y.

[0130] As shown in Figure 11 or Figure 20, along the second direction Y, the distance between the second step surface 231 and the second electrical connection surface 232 is W8, satisfying: 0.2mm ≤ W8 ≤ 0.7mm; for example, W8 can be located within the range of 0.2mm ≤ W8 ≤ 0.5mm, specifically, 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 second step surface 231 and the second electrical connection surface 232 within the above range makes it less likely that the height of the second connection part 20 will be too high, improving the space utilization of the battery and reducing the molding difficulty of the electrode post 2.

[0131] As shown in Figure 11 or Figure 20, the width of the second electrical connection surface 232 along the first direction X is W9. On a plane perpendicular to the second direction Y, i.e., on the plane formed by the first direction X and the third direction Y (including both directions X and Y), the width of the second step surface 231 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. Specifically, 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 232 has sufficient welding area.

[0132] As shown in Figure 11 or Figure 20, along the first direction X, the relationship between the maximum width W13 of the main body 230 and the maximum width W1 of the first electrical connection 120 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 arrangement, the widths of the second connection 20 and the first electrical connection 120 meet the welding area requirements.

[0133] Understandably, when the main body 230 does not have a second stepped surface 231, the width W9 of the second electrical connection surface 232 is equal to the maximum width W13 of the main body 230, that is, the entire surface of the main body 230 facing the electrode assembly 6 is used as the second electrical connection surface 232.

[0134] As shown in Figures 9, 13, 14, 17, 18, 22, 23, and 26, in one embodiment of the pole post, the second connecting portion 20 further includes a first flange portion 210. The first flange portion 210 is connected to one end face of the main body portion 230 along the second direction Y and extends toward the base portion 110. It can be understood that the first flange portion 210 is a structure that bends from the main body portion 230 toward the base portion 110. The first flange portion 210 is connected to the base portion 110. Along the second direction Y, one end of the third sub-part 233 is connected to the first flange portion 210, and the opposite end is connected to the fourth sub-part 234.

[0135] In some embodiments, the first flange portion 210 is directly connected to the base portion 110 without a fusible portion, such as the embodiments shown in FIG9 or FIG14. In other embodiments, the first flange portion 210 may also be connected to the base portion 110 through a fusible portion, such as the embodiments shown in FIG18 or FIG23.

[0136] As shown in Figures 10, 15, 19, or 24, along the second direction Y, the first flange portion 210 has a second surface 211 and a fourth surface 212 opposite to the second surface 211. The second surface 211 and the first surface 111 of the base portion 110 are located on the same side in the height direction of the pole post 2, and the fourth surface 212 and the third surface 112 of the base portion 110 are located on the same side in the height direction of the pole post 2. It can be understood that both the second surface 211 and the first surface 111 are located on the side of the pole post 2 facing outwards from the shell. Both the third surface 112 and the fourth surface 212 are located on the side of the pole post 2 facing inwards from the shell. The second surface 211 and the first surface 111 are in the same plane and form the first surface A; that is, the area of ​​the first surface 111 of the base portion 110 and the area of ​​the second surface 211 of the first flange portion 210 of the second connecting portion 20 together constitute the first surface A of the pole post 2. The third surface 112 and the fourth surface 212 are in the same plane and form the second surface B. In other words, the area of ​​the third surface 112 of the base portion 110 and the area of ​​the fourth surface 212 of the first flange portion 210 of the second connecting portion 20 together constitute the second surface B of the pole post 2.

[0137] The second surface 211 of the first flange 210 and the first surface 111 of the base 110 are set on the same plane to form the first surface A. The fourth surface 212 of the first flange 210 and the third surface 112 of the base 110 are set on the same plane to form the second surface B. On the one hand, the first surface A and the second surface B can be pressed by a mold to form the electrode post, making the processing of the electrode post more convenient. On the other hand, while ensuring that the first connecting part 10 and the second connecting part 20 have sufficient welding area, the width dimension of the electrode post 2 can be reduced, so that it can be applied to the battery cell with limited space in the top cover assembly design without affecting the performance of the battery cell. In other words, when the width dimension of the electrode post 2 is fixed, the weldable area of ​​the first connecting part 10 or the second connecting part 20 can be increased.

[0138] Furthermore, as shown in Figure 11 or Figure 20, on a plane perpendicular to the third direction Z, that is, on the plane composed of the first direction X and the second direction Y, the angle between the side wall of the main body 230 near the base part 110 and the fourth surface 212 is α, satisfying: 90°≤α≤95°. This creates a draft angle of 0–5° on the side wall of the main body 230, facilitating smooth demolding. Understandably, the entire circumferential side wall of the main body 230 has a draft angle of 0–5° to facilitate easy demolding of the main body 230 as a whole.

[0139] Referring to Figures 13 or 17, the fourth surface 212 of the first flange 210 is connected to the side wall of the main body 230 via a first arc segment 250. It can be understood that the fourth surface 212 of the first flange 210 and the side wall of the main body 230 are connected by an arc transition via the first arc segment 250. This arc transition facilitates the processing of the pole post 2 and also facilitates demolding after processing.

[0140] Please refer to Figures 10, 15, or 19. Along the first direction X, the distance between the side of the first flange portion 210 and the side of the main body portion 230 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. Specifically, 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 210 can be understood as the edge side of the first flange 210 along the first direction X. The side of the main body 230 can be understood as the edge side of the main body 230 along the first direction X. When the side wall of the main body 230 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 210 and the side of the main body 230. Through the above arrangement, on the one hand, the first flange 210 has sufficient width to facilitate the die pressing on the first flange 210 to punch the outer contour of the pole post 2, and on the other hand, the first flange 210 is not too wide, thus affecting the total width of the pole post 2.

[0141] As another embodiment of the second connecting portion 20 of the pole post 2, referring to Figures 9, 10, 14, 15, 18, 19, 23, and 24, the second connecting portion 20 includes a first flange portion 210 and a second flange portion 220. The second flange portion 220 is connected to one end face of the main body portion 230 along the second direction Y and extends in a direction away from the base portion 110. That is, the first flange portion 210 and the second flange portion 220 are arranged opposite to each other along the first direction X. Along the second direction Y, the second flange portion 220 has a fifth surface 221 and a sixth surface 222 arranged opposite to the fifth surface 221. The fifth surface 221 and the first surface A are located on the same side in the pole post height direction, that is, the fifth surface 221 and the first surface A are both located on the side facing the outside of the housing, and the sixth surface 222 is located on the side facing the inside of the housing. The fifth surface 221 is coplanar with the first surface A and forms the third surface C. That is, the fifth surface 221, together with the regions of the first surface 111 and the second surface 211 that make up the first surface A, constitutes the third surface C. The sixth surface 222 is coplanar with the second surface B and forms the fourth surface D. That is, the sixth surface 222, together with the regions of the third surface 112 and the fourth surface 212 that make up the second surface B, constitutes the fourth surface D. Thus, the base portion 110 of the first connecting portion 10 and the first flange portion 210 and the second flange portion 220 of the second connecting portion 20 are coplanar. The surface of the base portion 110 facing outwards from the shell is coplanar with the surfaces of the first flange portion 210 and the second flange portion 220 facing outwards from the shell, which is the third surface C. The surface of the base portion 110 facing inwards from the shell is coplanar with the surfaces of the first flange portion 210 and the second flange portion 220 facing inwards from the shell, which is the fourth surface D. The third surface C and the fourth surface D are parallel. In the processing of the electrode post 2, the various structural parts of the electrode post 2 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 2, namely the outer contour of the base part 110 and the outer contour of the first electrical connection part 120, is punched, so that the electrode post 2 is successfully dropped from the strip. With this setting, when the electrode post 2 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 2 can be punched out in the last step of the punching process, resulting in fewer punching burrs.

[0142] Furthermore, as shown in Figures 10, 15, 19 or 24, along the first direction X, the distance between the side of the second flange portion 220 and the side of the main body portion 230 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. Specifically, d can be any value between 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 220 can be understood as the edge side of the second flange 220 along the first direction X. When the side wall of the main body 230 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 220 and the side of the main body 230. With the above arrangement, on the one hand, the second flange 220 has sufficient width to facilitate the die pressing on the second flange 220 to punch the outer contour of the pole post 2, and on the other hand, the second flange 220 is not too wide so that the total width of the pole post 2 is not too large.

[0143] Since the first flange 210 is closer to the base portion 110 of the first connecting portion 10 than the second flange 220, current flows through the first flange 210. Therefore, in some embodiments, the distance c between the side of the first flange 210 and the side of the main body 230 is smaller than the distance d between the side of the second flange 220 and the side of the main body 230. This results in a relatively shorter current path for the first flange 210, leading to better current flow performance.

[0144] In some embodiments, referring to Figures 13, 17, or 22, the sixth surface 222 of the second flange 220 is connected to the side wall of the main body 230 via a second arc segment 260. It is understood that the transitional connection between the sixth surface 222 of the second flange 220 and the side wall of the main body 230 via the second arc segment 260 facilitates the processing of the pole post 2 and the demolding of the mold.

[0145] In some other embodiments, referring to Figures 9, 14, 15, or 23, the second connecting portion 20 includes a first flange 210, a second flange 220, a third flange 2201, and a fourth flange 2202. The third flange 2201 and the fourth flange 2202 are connected to one end face of the main body 230 along the second direction Y and extend away from the main body 230. Along the circumference of the second connecting portion 20, the first flange 210, the third flange 2201, the second flange 220, and the fourth flange 2202 are connected end to end in sequence. Since the first flange 210 and the second flange 220 are arranged opposite each other along the width direction of the second connecting portion 20, i.e., along the first direction X, and the third flange 2201 and the fourth flange 2202 are arranged opposite each other along the length direction of the second connecting portion 20, i.e., along the third direction Z, the third flange 2201 is connected to one end of the first flange 210 and the second flange 220, and the fourth flange 2202 is connected to the other end of the first flange 210 and the second flange 220. The third flange 2201 and the fourth flange 2202 can be arc-shaped or straight-shaped. Preferably, the third flange 2201 and the fourth flange 2202 are arc-shaped. The surfaces of the third flange 2201 and the fourth flange 2202 facing the outside of the shell are in the same plane as the third surface C. The surfaces of the third flange 2201 and the fourth flange 2202 facing the inside of the shell are in the same plane as the fourth surface D. Therefore, when punching the pole post 2, 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 2 can be punched out in the last step of punching, resulting in fewer punching burrs.

[0146] In some embodiments, as shown in Figures 10, 15, 19, and 24, the distance between the third surface C and the fourth surface D along the second direction Y 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 configuration ensures that the electrode post has a certain flow area and facilitates processing. When W5 is less than 0.5mm, the flow area between the third surface C and the fourth surface D of the electrode is small, making this location prone to deformation. When W5 is greater than 3mm, the thickness between the third surface C and the fourth surface D is large, increasing the cost and height of the electrode 2, reducing the space utilization of the battery cell and the battery. At the same time, it is difficult to stamp out the first electrical connection portion 120 protruding from the base portion 110 during the processing of the electrode, increasing the processing difficulty.

[0147] As one embodiment of the pole post, referring to Figures 13, 17, or 22, the main body 230 of the second connecting portion 20 includes a first sidewall 2123 and a second sidewall 2121. The first sidewall 2123 and the second sidewall 2121 are disposed opposite each other along a first direction X. One end face of the first sidewall 2123 along a second direction Y is connected to a first flange portion 210, which extends from the first sidewall 2123 toward the base portion 110. The first sidewall 2123 may be straight. One end face of the second sidewall 2121 along the second direction Y is connected to a second flange portion 220. The second flange portion 220 extends from the second sidewall 2121 in a direction away from the base portion 110. The second sidewall 2121 may be straight.

[0148] Since the first sidewall 2123 connects to the first flange 210, current flows through both the first sidewall 2123 and the first flange 210. Therefore, along the first direction X, the thickness of the first sidewall 2123 is greater than the thickness of the second sidewall 2121, thereby increasing the current-carrying area of ​​the first sidewall 2123. Since current does not flow through the second sidewall 2121, the thickness of the second sidewall 2121 can be set to be less than the thickness of the first sidewall 2123, thereby reducing the overall weight of the electrode post 2, saving material, and also reducing the width dimension of the electrode post 2.

[0149] In some other embodiments, referring to Figures 12, 16, or 21, the main body 230 includes a first sidewall 2123, a second sidewall 2121, a third sidewall 2122, and a fourth sidewall 2124, which are connected end-to-end along the circumference of the main body 230. The first sidewall 2123 and the second sidewall 2121 are disposed opposite to each other, and the third sidewall 2122 and the fourth sidewall 2124 are disposed opposite to each other. One end face of the third sidewall 2122 along the second direction Y is connected to the third flange portion 2201. One end face of the fourth sidewall 2124 along the second direction Y is connected to the fourth flange portion 2202. The third sidewall 2122 and the fourth sidewall 2124 can be curved (e.g., arc-shaped) or straight. In some embodiments, the third sidewall 2122 and the fourth sidewall 2124 are arc-shaped.

[0150] As one embodiment of the electrode post, as shown in Figures 9 to 26, the second connecting portion 20 has a first groove 21, which is recessed from the first surface A into the interior of the main body 230. That is, the first groove 21 extends from the first surface A into the interior of the main body 230. The opening of the first groove 21 is located on the first surface A. The opening of the first groove 21 can be higher than the side surface of the top cover plate 3 away from the interior of the housing. A second electrical connection portion 240 is formed on the bottom wall of the first groove 21. The second electrical connection portion 240 is connected to the tab 61, thereby making the second connecting portion 20 form a hollow structure, reducing the overall weight of the electrode post 2 and saving materials. It should be noted that the groove depth of the first groove 21 needs to take into account the weld penetration depth of the second electrical connection portion 240 and the tab 61, the material utilization rate, and the space utilization rate inside the housing. While saving materials, it is necessary to ensure the welding quality of both.

[0151] In some embodiments, on a plane perpendicular to the third direction Z, i.e., on the plane composed of the first direction X and the second direction Y, the angle between the groove wall surface of the first groove 21 near the base portion 110 and the fourth surface 212 is β, satisfying: 90°≤β≤95°. This creates a draft angle of 0–5° on the groove wall surface of the first groove 21, facilitating smooth mold demolding. Since the first groove 21 can be formed by a first sidewall 2123, a second sidewall 2121, a third sidewall 2122, a fourth sidewall 2124, and a groove bottom wall, and the inner sidewall 2123 facing the first groove 21 and the outer sidewall facing away from the first groove 21 are parallel, the groove wall surface of the first groove 21 also has an angle of 90°≤β≤95° with the fourth surface 212, thus facilitating demolding. It is understood that the entire circumferential groove wall surface of the first groove 21 has a draft angle of 0–5° to facilitate mold demolding.

[0152] In some embodiments, as shown in Figures 6 and 7, the bottom surface 2125 of the first groove 21 is located between the upper and lower surfaces of the top cover plate 3. The upper surface of the top cover plate 3 refers to the surface of the top cover plate 3 facing the outside of the housing. The lower surface of the top cover plate 3 refers to the surface of the top cover plate 3 facing the inside of the housing. This ensures the welding depth between the second electrical connection portion 240 and the tab 61, while reducing the overall height of the electrode post 2, thereby reducing the processing difficulty of the electrode post 2. In addition, it can save material of the electrode post 2 and improve the space utilization rate inside the battery cell.

[0153] In some embodiments, referring to Figures 13, 17, or 22, the groove wall surface and the groove bottom surface 2125 of the first groove 21 are connected by a third arc segment 270. It can be understood that the groove wall surface and the groove bottom surface 2125 of the first groove 21 are connected by an arc transition through the third arc segment 270, which facilitates the processing and demolding of the first groove 21.

[0154] In some embodiments, referring to Figures 13, 17, or 22, when the main body 230 has a first groove 21, the groove wall surface of the first groove 21 is connected to the second surface 211 of the first flange 210 via a fourth arc segment 280. It is understood that the groove wall surface of the first groove 21 and the second surface 211 of the first flange 210 are transitioned by the fourth arc segment 280, thus facilitating demolding after the first groove 21 is punched out of the pole post 2. In some embodiments, the groove wall surface of the first groove 21 is connected to the fifth surface 221 of the second flange 220 via a fifth arc segment 290. It is understood that the groove wall surface of the first groove 21 and the fifth surface 221 of the second flange 220 are transitioned by the fifth arc segment 290. This facilitates demolding after the first groove 21 is punched out of the pole post 2.

[0155] Of course, the electrode post 2 in this application can be a positive electrode post, as shown in the embodiments of Figures 9 to 13 or Figures 18 to 22; the electrode post 2 in this application can also be a negative electrode post, as shown in the embodiments of Figures 14 to 17 or Figures 23 to 26. When the electrode post 2 is a negative electrode post, the second connecting part 20 includes a first metal layer 22 and a second metal layer 23. Along the direction from the third surface C to the fourth surface D, the first metal layer 22 and the second metal layer 23 are stacked, with the second metal layer 23 located on the side of the first metal layer 22 facing the interior of the housing. The first metal layer 22 can be connected to the first connecting part 10 and is made of the same material. The second metal layer 23 covers the outside of the first metal layer 22. The second metal layer 23 directly contacts the negative electrode tab for welding. More specifically, in this embodiment, the first metal layer 22 is an aluminum layer, and the second metal layer 23 is a copper layer. Since the material of the negative electrode tab of the electrode assembly is generally also copper, the second metal layer 23 is made of the same material as the negative electrode tab to improve the welding effect between the negative electrode post and the negative electrode tab.

[0156] In some embodiments, a portion of the interface between the first metal layer 22 and the second metal layer 23 intersects with the sidewall surface of the second flange 220, as shown in Figures 14, 17, 23, and 26. The portion of the interface between the first metal layer 22 and the second metal layer 23 may also intersect with the sidewall surfaces of the third flange 2201 and the fourth flange 2202, as shown in Figure 14 or 23. The portion of the interface between the first metal layer 22 and the second metal layer 23 may also intersect with the sidewall surface of the first flange 210, as shown in Figure 23. It is understood that the sidewall surfaces refer to the circumferential side surfaces of the first flange 210, the second flange 220, the third flange 2201, and the fourth flange 2202. Since the first flange 210, the second flange 220, the third flange 2201, and the fourth flange 2202 are located on the surface of the top cover 3 facing the outside of the housing, the interface between the first metal layer 22 and the second metal layer 23 can extend to the circumferential side of the first flange 210, the second flange 220, the third flange 2201, and the fourth flange 2202 and be located on the outside of the top cover 3. This avoids the first metal layer 22, which is an aluminum layer, from contacting the electrolyte inside the housing and corroding, thereby affecting the safety performance of the battery.

[0157] As a preferred embodiment of the electrode post, as shown in FIG18 or FIG23, the electrode post 2 may further include a fusible portion 30, which connects the first connecting portion 10 and the second connecting portion 20. As shown in FIG19 or FIG24, along the second direction Y, the fusible portion 30 has a seventh surface 301 and an eighth surface 302 disposed opposite to each other, wherein the seventh surface 301 is in the same plane as the first surface A, and the eighth surface 302 is in the same plane as the second surface B. With the above arrangement, the electrode post 2 can be easily stamped and formed, making the processing of the electrode post 2 more convenient.

[0158] The fusible link can refer to a structural component that melts preferentially before the first connection part 10 and the second connection part 20 when thermal runaway occurs in a battery cell. This allows the fusible link 30 to promptly disconnect the circuit in the event of thermal runaway within the battery cell.

[0159] To ensure that the fuse portion 30 melts preferentially before the first connection portion 10 and the second connection portion 20 in the event of thermal runaway in a single battery cell, as shown in Figure 18, the length of the fuse portion 30 along the third direction Z is less than the length of the first connection portion 10 and less than the length of the second connection portion 20. This makes the current-carrying area of ​​the fuse portion 30 smaller than that of the first connection portion 10 and the second connection portion 20. The current-carrying area of ​​the fuse portion 30 refers to the surface area of ​​the fuse portion 30 perpendicular to the current flow direction, i.e., the minimum cross-sectional area of ​​the fuse portion 30. The current-carrying areas of the first connection portion 10 and the second connection portion 20 refer to the surface areas of the first connection portion 10 and the second connection portion 20 perpendicular to the current flow direction, i.e., the minimum cross-sectional areas of the first connection portion 10 and the second connection portion 20. Thus, in actual use, when a circuit malfunction occurs, the smaller current-carrying area of ​​the fuse portion 30 allows for faster temperature rise at the fuse portion 30, enabling it to melt quickly and promptly disconnect the circuit, greatly improving battery safety.

[0160] Understandably, the fuse part 30 can also reduce the current-passing area by slotting or opening, so as to ensure that the fuse can be broken in time to cut off the circuit when the circuit is abnormal.

[0161] Referring to Figures 6 to 8, in a preferred embodiment of the first insulating member 1, the first insulating member 1 of this application includes a first insulating portion 100, a second insulating portion 200, and a third insulating portion 300. The first insulating portion 100 is disposed on the side of the top cover plate 3 facing the interior of the housing. It is understood that the first insulating portion 100, disposed on the side of the top cover plate 3 facing the interior of the housing and forming an insulation with the second connecting portion 20, can prevent the second connecting portion 20 from contacting and electrically connecting with the top cover plate 3. Along the second direction Y, at least a portion of the orthographic projection of the first insulating portion 100 falls on the top cover plate 3; that is, on a plane perpendicular to the second direction Y, the orthographic projection of the first insulating portion 100 overlaps with the orthographic projection of the top cover plate 3. It is understood that at least a portion of the first insulating portion 100 is bent towards the inner side of the top cover plate 3 below the wall of the first through hole 31.

[0162] The second insulating portion 200 is disposed between the wall of the first through hole 31 and the second connecting portion 20 of the electrode post 2, so as to connect the second connecting portion 20 and the wall of the first through hole 31 through the second insulating portion 200 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 31. The second insulating portion 200 may be in the form of a ring structure, with one end of the second insulating portion 200 facing the inside of the housing connected to the first insulating portion 100, and the other end of the second insulating portion 200 facing the outside of the housing connected to the third insulating portion 300.

[0163] The third insulating portion 300 is located on the side of the top cover plate 3 facing the outside of the housing, that is, the third insulating portion 300 is located on the outer side of the top cover plate 3, so as to insulate the pole portion of the top cover plate 3 facing the outside of the housing and the top cover plate 3. At the same time, the third insulating portion 300 can also play a sealing role. Along the second direction Y, at least a portion of the orthographic projection of the third insulating portion 300 falls on the top cover plate 3, that is, in the plane perpendicular to the second direction Y, the orthographic projection of the third insulating portion 300 overlaps with the orthographic projection of the top cover plate 3. It can be understood that the outer contour edge of the third insulating portion 300 protrudes from the hole wall of the first through hole 31.

[0164] First, the first insulating part 100 and the second insulating part 200 are connected as a whole, forming an L-shape, which allows them to interlock with the top cover plate 3, improving the fixation effect on the terminal post 2. Furthermore, when at least a portion of the orthographic projection of the third insulating part 300 falls on the top cover plate 3, the first insulating part 100 and the third insulating part 300 can jointly lock the top cover plate 3 from both sides in the thickness direction, further improving the fixation effect on the terminal post 2. Secondly, the sealing ring structure in the top cover assembly of related technologies can be eliminated, thus eliminating the size requirement of the sealing ring in the width direction of the top cover plate 3. Therefore, only the dimensions of the outer casing film at the edge of the top cover plate 3 to the edge of the first insulating member 1, the dimensions of the two second connecting parts 20, and the dimensions of the first connecting part 10 need to be considered. Even for battery cells with small thicknesses and limited design width, the welding area of ​​the first connecting part 10 and the second connecting part 20 can be guaranteed, thus not affecting the battery's charging and discharging performance and safety performance. Finally, the second insulating part 200 passes through the first through hole 31, which can prevent the electrolyte from leaking out of the first through hole 31 due to compression failure of the sealing ring during long-term use. Furthermore, the first insulating part 100, the second insulating part 200 and the third insulating part 300 are connected as one unit, which can increase the sealing path for sealing the hole wall of the first through hole 31, further preventing the electrolyte from leaking out of the first through hole 31.

[0165] In this embodiment, the first insulating portion 100, the second insulating portion 200, and the third insulating portion 300 of the first insulating member 1 are integrally formed. Furthermore, the first insulating portion 100, the second insulating portion 200, and the third insulating portion 300 are integrally nano-injection molded. Nano-injection molding is a process technology that tightly bonds metal and plastic. By integrally nano-injection molding the first insulating portion 100, the second insulating portion 200, and the third insulating portion 300, the sealing performance of the battery cell can be greatly improved, thus further ensuring that the sealing ring can be eliminated in this application. Of course, in other embodiments, the first insulating portion 100, the second insulating portion 200, and the third insulating portion 300 can also be formed separately first, and then connected by bonding, heat fusion, or other methods.

[0166] Specifically, the surfaces of the top cover plate 3 that contact the first insulating part 100 and the second insulating part 200 are provided with first nanopores, and at least a portion of the first insulating part 100 and the second insulating part 200 are embedded in the first nanopores; this can increase the bonding force and sealing performance between the first insulating part 100, the second insulating part 200 and the top cover plate 3. During the manufacturing process, a nanopore structure can be formed on the lower surface of the top cover plate 3 and the hole wall of the first through hole 31 by chemical etching, thereby increasing the contact surface area of ​​the first insulating part 100, the second insulating part 200 and the top cover plate 3, and improving the bonding force and sealing performance.

[0167] In some embodiments, the surfaces of the electrode post 2 that contact the first insulating portion 100 and the second insulating portion 200 are provided with second nanopores, and the first insulating portion 100 and the second insulating portion 200 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 20 of the electrode post 2 by chemical etching to increase the contact surface area with the first insulating portion 100 and the second insulating portion 200, thereby improving the bonding force and sealing performance between the first insulating portion 100, the second insulating portion 200 and the electrode post 2.

[0168] In some embodiments, the surface of the top cover plate 3 that contacts the third insulating portion 300 is provided with a third nanopore, and at least a portion of the third insulating portion 300 is embedded in the third nanopore. During the manufacturing process, a nanopore structure can be formed on the outer surface of the top cover plate 3, the bottom surface of the second groove 32, and the groove wall surface by chemical etching, thereby increasing the contact surface area between the third insulating portion 300 and the top cover plate 3 and improving the bonding force and sealing performance between the third insulating portion 300 and the top cover plate 3.

[0169] In some embodiments, the surface of the pole post 2 that contacts the third insulating portion 300 is provided with a fourth nanopore, and at least a portion of the third insulating portion 300 is embedded in the fourth nanopore. During the manufacturing process, nanoporous structures can be formed by chemical etching on the third surface C, the fourth surface D, the bottom surface 2125 and the wall surface of the first groove 21 of the second connecting portion 20, the circumferential side surfaces of the second flange portion 220, the third flange portion 2201 and the fourth flange portion 2202, and the circumferential side surfaces of the base portion 110 of the first connecting portion 10. Alternatively, in some other embodiments, nanoporous structures can be formed by chemical etching on the third surface C, the fourth surface D, the bottom surface 2125 and the wall surface of the first groove 21 of the second connecting portion 20, the circumferential side surfaces of the second flange portion 220, the third flange portion 2201 and the fourth flange portion 2202, the circumferential side surfaces of the base portion 110 of the first connecting portion 10, and the upper and lower surfaces of the fused portion 30. This increases the contact surface area between the third insulating portion 300 and the pole post 2, thereby improving the bonding force and sealing performance between the third insulating portion 300 and the pole post 2.

[0170] As one embodiment of the top cover assembly, please refer to Figures 6 to 8. The top cover sheet 3 may also be provided with a second insulating member 4. The second insulating member 4 is provided on the surface of the top cover sheet 3 facing the inside of the housing, and is used to insulate the top cover sheet 3 and the electrode assembly 6 to reduce the risk of short circuit. For example, the second insulating member 4 may be a plastic material, such as PP, PE, PPS, etc.

[0171] Specifically, referring to Figure 8, the second insulating member 4 is provided with a second through hole 41 corresponding to the first through hole 31. The second through hole 41 penetrates the thickness direction of the second insulating member 4. The second connecting part 20 passes through the first through hole 31 and the second through hole 41 in sequence so that the second connecting part 20 can be welded to the electrode tab 61.

[0172] The top cover plate 3 may also be provided with a pressure relief mechanism 7 for releasing internal pressure when the internal pressure or temperature of the battery cell 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 top cover plate 3, it is less likely for the battery cell to experience thermal runaway.

[0173] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An electrode post, characterized in that, include: At least one first connecting portion (10) for connection with an electrical connector, along a second direction (Y), the first connecting portion (10) has a third surface (112); at least two second connecting portions (20) for connection with electrodes, each of the first connecting portions (10) is disposed between two adjacent second connecting portions (20) and connected to the two adjacent second connecting portions (20), the at least two second connecting portions (20) are arranged at intervals along a first direction (X), the second connecting portion (20) includes a main body portion (230) and a first flange portion (210), the first flange portion (210) is connected to one end face of the main body (230) along the second direction (Y) and extends toward the first connecting part (10). The first flange (210) is connected to the first connecting part (10). Along the second direction (Y), the first flange (210) has a fourth surface (212). The fourth surface (212) and the third surface (112) are located on the same side in the height direction of the pole post, and the fourth surface (212) and the third surface (112) are in the same plane and form a second surface (B). The first direction (X) and the second direction (Y) intersect.

2. The pole post according to claim 1, characterized in that, The first connecting portion (10) includes a base portion (110) and a first electrical connection portion (120). Along the second direction (Y), the base portion (110) has the third surface (112), and the first electrical connection portion (120) is disposed on the surface of the base portion (110) opposite to the third surface (112). The first flange portion (210) is connected to the base portion (110). Along the second direction (Y), the base portion (110) has a first surface (111) opposite to the third surface (112), and the first flange portion (210) has a second surface (211) opposite to the fourth surface (212). The first surface (111) and the second surface (211) are in the same plane and form a first surface (A).

3. The pole post according to claim 2, characterized in that, The second connecting portion (20) further includes a second flange portion (220), which is connected to one end face of the main body portion (230) along the second direction (Y) and extends away from the base portion (110). The second flange portion (220) is disposed opposite to the first flange portion (210) along the first direction (X). Along the second direction (Y), the second flange portion (220) has a fifth surface (221), which is in the same plane as the first surface (A) and forms a third surface (C). Along the second direction (Y), the second flange portion (220) also has a sixth surface (222) disposed opposite to the fifth surface (221), which is in the same plane as the second surface (B) and forms a fourth surface (D). The third surface (C) and the fourth surface (D) are parallel.

4. The electrode post according to claim 3, characterized in that, The second connecting part (20) further includes a third flange (2201) and a fourth flange (2202) along a third direction (Z). The third flange (2201) connects one end of the first flange (210) and the second flange (220), and the fourth flange (2202) connects the other end of the first flange (210) and the second flange (220).

5. The electrode post according to claim 3, characterized in that, Along the first direction (X), the distance between the side surface of the first flange (210) and the side surface of the main body (230) is c, satisfying: 0.5mm ≤ c ≤ 5mm; and / or, along the first direction (X), the distance between the side surface of the second flange (220) and the side surface of the main body (230) is d, satisfying: 0.5mm ≤ d ≤ 5mm; and / or, the distance c between the side surface of the first flange (210) and the side surface of the main body (230) is less than the distance c between the side surface of the second flange (220) and the side surface of the main body (230). The distance d between the surface and the side of the main body (230); and / or, along the third direction (Z), the minimum distance a between the edge side of the first electrical connection part (120) and the edge side of the base part (110) is 0.2mm≤a≤5mm, wherein the third direction (Z) intersects the first direction (X) and the second direction (Y) respectively; and / or, along the second direction (Y), the distance W5 between the third surface (C) and the fourth surface (D) is 0.5mm≤W5≤3mm.

6. The pole post according to claim 2, characterized in that, The second connecting portion (20) has a first groove (21) that is recessed from the first surface (A) into the body portion (230).

7. The pole post according to claim 3, characterized in that, The main body (230) includes a first sidewall (2123) and a second sidewall (2121). The first sidewall (2123) and the second sidewall (2121) are arranged opposite to each other along the first direction (X). One end face of the first sidewall (2123) along the second direction (Y) is connected to the first flange (210), and one end face of the second sidewall (2121) along the second direction (Y) is connected to the second flange (220). Along the first direction (X), the thickness of the first sidewall (2123) is greater than the thickness of the second sidewall (2121).

8. The pole post according to claim 3, characterized in that, The second connecting portion (20) includes a first metal layer (22) and a second metal layer (23). The first metal layer (22) and the second metal layer (23) are stacked in a direction from the third surface (C) to the fourth surface (D). At least part of the interface between the first metal layer (22) and the second metal layer (23) intersects with the sidewall surface of the second flange portion (220).

9. The pole post according to claim 2, characterized in that, The first electrical connection portion (120) includes a first sub-part (123) and a second sub-part (124). Along the second direction (Y), one end of the first sub-part (123) is connected to the base portion (110), and the other end is connected to the second sub-part (124). Along the second direction (Y), on a plane perpendicular to the second direction (Y), the orthographic projection of the second sub-part (124) falls within the orthographic projection range of the first sub-part (123). A first step surface (121) is connected between the side wall surface of the first sub-part (123) and the side wall surface of the second sub-part (124). The surface of the second sub-part (124) away from the first sub-part (123) is the first electrical connection surface (122).

10. The pole post according to claim 9, characterized in that, In a plane perpendicular to the second direction (Y), the width of the first step surface (121) is W3, satisfying: 0.3mm≤W3≤1mm; and / or, along the second direction (Y), the distance between the first step surface (121) and the first electrical connection surface (122) is W4, satisfying: 0.2mm≤W4≤0.7mm; and / or, along the second direction (Y), the distance between the first step surface (121) and the first electrical connection surface (122) is W4, and the distance between the first electrical connection surface (122) and the first surface (A) is W6, satisfying: 15%≤W4 / W6≤50%; and / or, along the first direction (X), the maximum width of the first electrical connection portion (120) is W1, and in a plane perpendicular to the second direction (Y), the width of the first step surface (121) is W3, satisfying: 1%≤W3 / W1≤10%.

11. The pole post according to claim 1, characterized in that, The main body (230) includes a third sub-part (233) and a fourth sub-part (234). Along the second direction (Y), one end of the third sub-part (233) is connected to the first flange (210), and the other end is connected to the fourth sub-part (234). Along the second direction (Y), on a plane perpendicular to the second direction (Y), the orthographic projection of the fourth sub-part (234) falls within the orthographic projection range of the third sub-part (233). A second step surface (231) is connected between the side wall surface of the fourth sub-part (234) and the side wall surface of the third sub-part (233). The surface of the fourth sub-part (234) away from the third sub-part (233) is a second electrical connection surface (232).

12. The pole post according to claim 11, characterized in that, In a plane perpendicular to the second direction (Y), the width of the second step surface (231) is W7, satisfying: 0.3mm≤W7≤1mm; and / or, along the second direction (Y), the distance between the second step surface (231) and the second electrical connection surface (232) is W8, satisfying: 0.2mm≤W8≤0.7mm; and / or, along the first direction (X), the width of the second electrical connection surface (232) is W9, and in a plane perpendicular to the second direction (Y), the width of the second step surface (231) is W7, satisfying: 2%≤W7 / W9≤20%.

13. The pole post according to any one of claims 2 to 12, characterized in that, Along the first direction (X), the maximum width of the first electrical connection portion (120) is W1, satisfying: 8mm≤W1≤35mm; and / or, along the first direction (X), the maximum width of the pole post is W2, satisfying: 14mm≤W2≤80mm; and / or, along the first direction (X), the maximum width of the first electrical connection portion (120) is W1, and the maximum width of the pole post is W2, satisfying: 20%≤W1 / W2≤60%; and / or, along the second direction (Y), the distance between the first electrical connection surface (122) of the first electrical connection portion (120) and the first surface (A) is W6, satisfying: 0.7mm≤W6≤2mm; and / or, along the third direction (Z), the maximum width of the base portion (110) of the first connection portion (10) is... The length is W10, satisfying: 15mm≤W10≤50mm; and / or, along the third direction (Z), the maximum length of the base portion (110) of the first connecting portion (10) is W10, and the maximum length of the first electrical connecting portion (120) is W11, satisfying: 85%≤W11 / W10≤98%; and / or, along the third direction (Z), the maximum length of the base portion (110) of the first connecting portion (10) is W10, and the maximum length of the second connecting portion (20) is W12, satisfying: 80%≤W10 / W12≤100%; and / or, along the first direction (X), the maximum width of the first electrical connecting portion (120) is W1, and the maximum width of the main body portion (230) is W13, satisfying: 35%≤W13 / W1≤75%.

14. The pole post according to any one of claims 2 to 12, characterized in that, On a plane perpendicular to the third direction (Z), the angle between the side wall of the main body (230) near the base part (110) and the fourth surface (212) is α, satisfying: 90°≤α≤95°; and / or, the second connecting part (20) has a first groove (21), the first groove (21) is recessed from the first surface (A) into the main body (230), and on a plane perpendicular to the third direction (Z), the angle between the groove wall of the first groove (21) near the base part (110) and the fourth surface (212) is β, satisfying: 90°≤β≤95°.

15. The pole post according to any one of claims 2 to 12, characterized in that, The fourth surface (212) of the first flange (210) is connected to the side wall of the main body (230) by a first arc segment (250); and / or, the second connecting portion (20) includes a second flange (220) extending away from the base portion (110), the second flange (220) being disposed opposite to the first flange (210) along the first direction (X), and the sixth surface (222) of the second flange (220) being connected to the side wall of the main body (230) by a second arc segment (260); and / or, the second connecting portion (20) has a first groove (21) extending from the first surface (A) toward the main body (230). The interior is recessed, and the groove wall surface of the first groove (21) is connected to the groove bottom surface (2125) by a third arc segment (270); and / or, the second connecting part (20) has a first groove (21), the first groove (21) is recessed from the first surface (A) into the interior of the main body (230), and the groove wall surface of the first groove (21) is connected to the second surface (211) of the first flange (210) by a fourth arc segment (280); and / or, the second connecting part (20) includes a second flange (220), the second connecting part (20) has a first groove (21), and the groove wall surface of the first groove (21) is connected to the fifth surface (221) of the second flange (220) by a fifth arc segment (290).

16. The pole post according to any one of claims 2 to 12, characterized in that, Also includes: A fusible portion (30) is connected between the first connecting portion (10) and the second connecting portion (20) along the second direction (Y). The fusible portion (30) has a seventh surface (301) and an eighth surface (302) disposed opposite to each other, wherein the seventh surface (301) is in the same plane as the first surface (A); and / or the eighth surface (302) is in the same plane as the second surface (B).

17. A top cover assembly, characterized in that, include: The top cover (3) and the pole post (2) as described in any one of claims 1 to 16; the top cover (3) has a first through hole (31) along its thickness direction, the first connecting part (10) is disposed on one side of the top cover (3), the second connecting part (20) is at least partially inserted into the first through hole (31), and the second direction (Y) is the thickness direction of the top cover (3).

18. A top cover assembly, characterized in that, include: The top cover (3) and the pole (2) are provided. The top cover (3) has a first through hole (31) along its thickness direction. The pole (2) includes: at least one first connecting part (10) for connecting with an electrical connector. The first connecting part (10) has a third surface (112) along the second direction (Y); at least two second connecting parts (20) for connecting with a tab. The second connecting parts (20) are at least partially inserted into the first through hole (31). Each first connecting part (10) is disposed between two adjacent second connecting parts (20) and connected to the two adjacent second connecting parts (20). The at least two second connecting parts (20) are arranged at intervals along the first direction (X). The second connecting part (20) includes a main body. The main body (230) and the first flange (210) are connected to one end face of the main body (230) along the second direction (Y) and extend toward the first connecting part (10). The first flange (210) is connected to the first connecting part (10). Along the second direction (Y), the first flange (210) has a fourth surface (212). The fourth surface (212) and the third surface (112) are located on the same side in the height direction of the pole post, and the fourth surface (212) and the third surface (112) are in the same plane and form a second surface (B). The first direction (X) and the second direction (Y) intersect. The second direction (Y) is the thickness direction of the top cover (3).

19. The top cover assembly according to claim 18, characterized in that, The first connecting portion (10) includes a base portion (110) and a first electrical connection portion (120). Along the second direction (Y), the base portion (110) has the third surface (112), and the first electrical connection portion (120) is disposed on the surface of the base portion (110) opposite to the third surface (112). The first flange portion (210) is connected to the base portion (110). Along the second direction (Y), the base portion (110) has a first surface (111) opposite to the third surface (112), and the first flange portion (210) has a second surface (211) opposite to the fourth surface (212). The first surface (111) and the second surface (211) are in the same plane and form a first surface (A).

20. The top cover assembly according to claim 19, characterized in that, The second connecting portion (20) further includes a second flange portion (220), which is connected to one end face of the main body portion (230) along the second direction (Y) and extends away from the base portion (110). The second flange portion (220) is disposed opposite to the first flange portion (210) along the first direction (X). Along the second direction (Y), the second flange portion (220) has a fifth surface (221), which is in the same plane as the first surface (A) and forms a third surface (C). Along the second direction (Y), the second flange portion (220) also has a sixth surface (222) disposed opposite to the fifth surface (221), which is in the same plane as the second surface (B) and forms a fourth surface (D). The third surface (C) and the fourth surface (D) are parallel.

21. A single battery cell, characterized in that, include: A housing (5) having an opening; an electrode assembly (6) having tabs (61) therein, the electrode assembly (6) being received within the housing (5); and a top cover assembly as claimed in any one of claims 17 or 18 to 20, covering the opening of the housing (5).

22. A battery, characterized in that, Includes the battery cell as described in claim 21.

23. An electrical appliance, characterized in that, It includes the battery cell of claim 21, or the battery of claim 22.

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