Top cover assembly, battery monomer, battery and electric device

Abstract

The utility model provides a top cover assembly, a battery monomer, a battery and a power utilization device, and relates to the technical field of batteries, the top cover assembly comprises a top cover sheet, a pole and a first insulating piece, the top cover sheet is provided with a first surface, a second surface and a first through hole, the pole comprises at least one first connecting part and at least two second connecting parts, the first connecting part is arranged on one side, provided with the first surface, of the top cover sheet and is used for being connected with an electric connecting piece, and the second connecting part is used for being connected with a tab; the first insulating part is fixedly connected to the pole and the top cover piece and comprises a second insulating part and a third insulating part which are connected, the second insulating part is arranged between the hole wall of the first through hole and the second connecting part of the pole, and the third insulating part is arranged on the side, provided with the first face, of the top cover piece; therefore, the first insulating part has fixing, insulating and sealing effects at the same time.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to 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 draw current out of the electrode assembly. Therefore, the current-carrying capacity of the terminals affects the battery's charge / discharge capacity and safety performance. In related technologies, a battery cell consists of a top cover assembly, electrode assembly, and casing. However, for battery cells with relatively small thicknesses, the limited width design space of the top cover assembly restricts the design size of the terminals, resulting in weaker current-carrying capacity and hindering the improvement of battery charge / discharge performance and safety. Utility Model Content

[0003] The purpose of this application is to provide a top cover assembly, a battery cell, a battery, and an electrical device to solve the technical problem in the prior art where the limited design space of the top cover assembly leads to the limitation of the terminal post design size, which in turn is not conducive to improving battery performance.

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

[0005] In a first aspect, this application provides a top cover assembly, comprising: a top cover sheet, an electrode post, and a first insulating member. The top cover sheet has a first surface, a second surface, and a first through hole, wherein the first surface and the second surface are disposed opposite to each other, and the first through hole penetrates through the first surface and the second surface. The electrode post includes at least one first connecting portion and at least two second connecting portions, and each first connecting portion is connected to two adjacent second connecting portions. The at least two second connecting portions are arranged at intervals along the width direction of the top cover sheet. The first connecting portion is disposed on the side of the top cover sheet having the first surface and is used to connect with an electrical connector. At least a portion of the second connecting portion passes through the first through hole and is used to connect with a tab. The first insulating member is fixedly connected to the electrode post and the top cover sheet, and includes a second insulating portion and a third insulating portion connected thereto. The second insulating portion is disposed between the hole wall of the first through hole and the second connecting portion of the electrode post, and the third insulating portion is disposed on the side of the top cover sheet having the first surface.

[0006] In one or more embodiments of this application, the second connecting portion has a first groove. Along the thickness direction of the top cover sheet, the opening of the first groove is formed on the surface of the second connecting portion near the first connecting portion, and the bottom surface of the first groove is located between the first surface and the second surface.

[0007] In one or more embodiments of this application, the second connecting portion is provided with a flange around the opening of the first groove, and the flange is located on the side of the top cover sheet having the first surface along the thickness direction of the top cover sheet.

[0008] In one or more embodiments of this application, on a dummy plane perpendicular to the thickness direction of the top cover sheet, the orthographic projection of the flanged portion overlaps with the orthographic projection of the top cover sheet.

[0009] In one or more embodiments of this application, the second connecting portion includes a first metal layer and a second metal layer, which are stacked along the thickness direction of the second connecting portion, and at least a portion of the interface between the first metal layer and the second metal layer intersects with the sidewall surface of the flange portion.

[0010] In one or more embodiments of this application, the width of the top cover sheet is W1 along the width direction, and the minimum distance between the side wall of the flange and the edge of the top cover sheet is W4, satisfying: 5% ≤ W4 / W1 ≤ 20%.

[0011] In one or more embodiments of this application, along the width direction of the top cover sheet, the minimum distance between the side of the flange and the edge of the top cover sheet is W4, which satisfies: 3mm≤W4≤10mm.

[0012] In one or more embodiments of this application, the width of the top cover is W1, which satisfies: W1≥20mm.

[0013] In one or more embodiments of this application, the second connecting portion is a plate-like structure, and along the thickness direction of the top cover sheet, the second connecting portion has a third surface disposed close to the first connecting portion, and the third surface is located between the first surface and the second surface.

[0014] In one or more embodiments of this application, the pole post further includes a transition portion, which connects the first connecting portion and the second connecting portion along the width direction of the top cover sheet, and at least a portion of the transition portion is projected onto the first through hole along the thickness direction of the top cover sheet.

[0015] In one or more embodiments of this application, along the length direction of the top cover sheet, the length of the transition portion is less than the length of the first connecting portion and less than the length of the second connecting portion; the first through hole has a notch to accommodate the transition portion.

[0016] In one or more embodiments of this application, the second connecting portion is a plate-like structure. Along the thickness direction of the top cover sheet, the second connecting portion has a third surface disposed near the first connecting portion. The third surface is flush with the first surface of the top cover sheet, or the third surface protrudes from the first surface of the top cover sheet.

[0017] In one or more embodiments of this application, the surfaces of the top cover sheet that are in contact with the second insulating portion are provided with first nanopores, and at least a portion of the second insulating portion is embedded in the first nanopores.

[0018] In one or more embodiments of this application, the surfaces of the pole post that are in contact with the second insulating portion are provided with second nanopores, and the second insulating portion is at least partially embedded in the second nanopores.

[0019] In one or more embodiments of this application, on a dummy plane perpendicular to the thickness direction of the top cover sheet, the orthographic projection of the third insulating portion overlaps with the orthographic projection of the top cover sheet, and the surface of the top cover sheet in contact with the third insulating portion is provided with a third nanopore, and at least a portion of the third insulating portion is embedded in the third nanopore.

[0020] In one or more embodiments of this application, a fourth nanopore is provided on the surface of the pole that contacts the third insulating part, and at least a portion of the third insulating part is embedded in the fourth nanopore.

[0021] In one or more embodiments of this application, the second insulating portion and the third insulating portion of the first insulating member are integrally formed.

[0022] In one or more embodiments of this application, along the thickness direction of the top cover sheet, the orthographic projection of the first connecting portion on the top cover sheet does not overlap with the first through hole, the outer contour of the first connecting portion has at least a first outer peripheral surface, and along the width direction of the top cover sheet, the minimum distance between the first outer peripheral surface and the hole wall of the first through hole is W5, satisfying: 0≤W5≤10mm.

[0023] In one or more embodiments of this application, along the thickness direction of the top cover sheet, the orthographic projection of the first connecting portion on the top cover sheet overlaps with the first through hole portion, the outer contour of the first connecting portion has at least a first outer peripheral surface, and along the width direction of the top cover sheet, the distance between the first outer peripheral surface and the hole wall of the first through hole is W5, satisfying: 0≤W5≤10mm.

[0024] In one or more embodiments of this application, a second groove is provided on the first surface of the top cover sheet. The second groove is recessed from the first surface to the second surface. The top cover sheet includes at least two first through holes. Each second connecting part is correspondingly disposed in a first through hole. The at least two first through holes respectively penetrate the bottom wall of the second groove along the thickness direction of the top cover sheet.

[0025] In one or more embodiments of this application, the thickness of the top cover sheet is T2 along the thickness direction of the top cover sheet, satisfying: 1.5mm≤T2≤3mm.

[0026] In one or more embodiments of this application, along the thickness direction of the top cover sheet, the groove depth of the second groove is T1, satisfying: 0.3mm≤T1≤1.5mm.

[0027] In one or more embodiments of this application, along the thickness direction of the top cover sheet, the groove depth of the second groove is T1, and the thickness of the top cover sheet is T2, satisfying: 10% ≤ T1 / T2 ≤ 80%.

[0028] In one or more embodiments of this application, the top cover sheet is provided with a through hole along the thickness direction of the top cover sheet, and a support portion is provided in the through hole. The two ends of the support portion, which are arranged opposite to each other along its longitudinal direction, are respectively connected to the two side holes of the through hole, which are arranged opposite to each other along the length direction of the top cover sheet, and divide the through hole into two first through holes spaced apart along the width direction of the top cover sheet. Along the thickness direction of the top cover sheet, the first surface of the top cover sheet protrudes from the support portion.

[0029] In one or more embodiments of this application, along the thickness direction of the top cover sheet, the support portion has a fourth surface close to the first surface, and the distance between the fourth surface of the support portion and the first surface is T3, which satisfies: 0.3mm≤T3≤1.5mm.

[0030] In one or more embodiments of this application, the thickness of the top cover sheet is T2 along the thickness direction of the top cover sheet, and the distance between the fourth surface and the first surface of the support portion is T3, satisfying: 10% ≤ T3 / T2 ≤ 80%.

[0031] In one or more embodiments of this application, along the thickness direction of the top cover sheet, the surface of the first connecting portion near the top cover sheet is the fifth surface, the first surface of the top cover sheet is provided with a second groove, and the distance between the fifth surface and the bottom wall of the second groove is W6, which satisfies: 0.5mm≤W6≤1.2mm.

[0032] In one or more embodiments of this application, a through hole is provided in the top cover sheet along the thickness direction, and a support portion is provided in the through hole. The two ends of the support portion, which are arranged opposite to each other along its longitudinal direction, are respectively connected to the two side walls of the through hole, which are arranged opposite to each other along the length direction of the top cover sheet, and divide the through hole into two first through holes spaced apart along the width direction of the top cover sheet. The side surface of the support portion near the first connecting portion is the fourth surface, and the distance between the fifth surface and the fourth surface of the support portion is W6, which satisfies: 0.5mm≤W6≤1.2mm.

[0033] In one or more embodiments of this application, along the width direction of the top cover sheet, the maximum width of the first connecting portion is W2, and the width W1 of the top cover sheet satisfies: 20% ≤ W2 / W1 ≤ 60%.

[0034] In one or more embodiments of this application, the maximum width of the first connecting portion along the width direction of the top cover sheet is W2, which satisfies: 8mm≤W2≤35mm.

[0035] In one or more embodiments of this application, the width of the top cover sheet is W1 along the width direction of the top cover sheet, satisfying: W1≥20mm.

[0036] In one or more embodiments of this application, the outer contour of the first connecting portion has at least a first outer peripheral surface. Along the width direction of the top cover sheet, the minimum distance between the first outer peripheral surface and the edge of the top cover sheet is W3, and the width of the top cover sheet is W1, satisfying: 25% ≤ W3 / W1 ≤ 40%.

[0037] In one or more embodiments of this application, a third insulating portion covers the surface of the pole located on the side of the first face, and at least exposes the first electrical connection surface of the first connection portion.

[0038] In one or more embodiments of this application, the circumferential outer edge of the third insulating portion is set at an obtuse angle to the first surface of the top cover sheet.

[0039] In one or more embodiments of this application, the first surface of the top cover sheet is provided with a second groove, and the distance between the outer circumferential edge of the third insulating part and the groove sidewall of the second groove is a, which satisfies: 0.3mm≤a≤2mm.

[0040] In one or more embodiments of this application, it further includes: a second insulating member, the second insulating member being disposed on one side of the top cover sheet having a second surface, the second insulating member having a second through hole corresponding to the first through hole, the second through hole penetrating through the thickness direction of the second insulating member, and the second connecting portion passing through the first through hole and the second through hole in sequence.

[0041] In one or more embodiments of this application, the first insulating member further includes a first insulating portion connected to the second insulating portion, the first insulating portion being disposed on the side of the top cover sheet having a second surface.

[0042] In one or more embodiments of this application, on a dummy plane perpendicular to the thickness direction of the top cover sheet, the orthographic projection of the first insulating portion overlaps with the orthographic projection of the top cover sheet; or, along the thickness direction of the top cover sheet, the orthographic projection of the first insulating portion falls entirely within the first through hole. In one or more embodiments of this application, the second connecting portion includes a third sub-portion and a fourth sub-portion. Along the thickness direction of the top cover sheet, and on a plane perpendicular to the thickness direction of the top cover sheet, the orthographic projection of the fourth sub-portion falls within the orthographic projection range of the third sub-portion. A second stepped surface connects the sidewall surface of the fourth sub-portion and the sidewall surface of the third sub-portion. The surface of the fourth sub-portion away from the third sub-portion is a second electrical connection surface. The second stepped surface is flush with the surface of the first insulating portion facing away from the top cover sheet.

[0043] Secondly, this application also provides a battery cell, comprising: a housing, an electrode assembly, and a top cover assembly as described in any one of the first 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.

[0044] Thirdly, this application also provides a battery, including the battery cell described in the second aspect.

[0045] Fourthly, this application also provides an electrical device, including the battery cell described in the second aspect or the battery described in the third aspect.

[0046] Based on the above technical solution, the top cover assembly, battery cell, battery, and power device of this application have at least the following beneficial technical effects:

[0047] The top cover assembly provided in this application embodiment, by configuring the first insulating member to include a second insulating portion and a third insulating portion, and further by having the second insulating portion disposed between the hole wall of the first through hole of the top cover sheet and the second connecting portion of the electrode post, insulates the hole wall of the first through hole of the top cover sheet and the electrode post, while also providing a sealing function to prevent electrolyte leakage from the first through hole, and by having the third insulating portion disposed on the surface of the top cover sheet facing the outer side of the housing, insulates the upper surface of the top cover sheet and the electrode post. The first insulating member of this application embodiment simultaneously has the functions of fixing, insulating and sealing, therefore, the sealing ring in the top cover assembly of related technologies can be eliminated. The structure eliminates the need to consider the size of the sealing ring in the width direction of the top cover sheet. Instead, it only needs to consider the size of the outer casing film at the edge of the top cover sheet to the edge of the first insulating component, the size of the two second connecting parts, and the size of the first connecting part. Even for battery cells with small thickness and limited design width of the top cover sheet, the weldable area of ​​the first connecting part and the weldable area of ​​the second connecting part can be guaranteed, thus not affecting the charging and discharging performance and safety performance of the battery. In other words, when the size of the terminal post along the width direction of the top cover sheet is fixed, the weldable area of ​​the first connecting part and the weldable area of ​​the second connecting part can be increased.

[0048] The battery cell provided in this application includes a top cover assembly. Since the top cover assembly eliminates the sealing ring structure, the width of the top cover assembly can be adapted and applied to battery cells with smaller thickness, thereby improving the charging and discharging performance and safety performance of the battery cell. In other words, when the width of the top cover assembly is fixed, the weldable area of ​​the first connection part and the weldable area of ​​the second connection part can be increased, thereby improving the charging and discharging performance and safety performance of the battery cell. Attached Figure Description

[0049] 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.

[0050] Figure 1 This is a three-dimensional structural diagram of a battery cell provided in an embodiment of this application.

[0051] Figure 2This is a schematic diagram of the main structure of a battery cell provided in an embodiment of this application.

[0052] Figure 3 yes Figure 2 AA section view.

[0053] Figure 4 yes Figure 2 BB cross-section diagram.

[0054] Figure 5 This is a three-dimensional structural diagram of the top cover assembly provided in the embodiments of this application.

[0055] Figure 6 This is an exploded disassembly diagram of the top cover assembly provided in an embodiment of this application.

[0056] Figure 7 This is a side view of the top cover assembly provided in an embodiment of this application.

[0057] Figure 8 yes Figure 7 BB cross-section diagram.

[0058] Figure 9 This is a three-dimensional structural diagram of the pole post in the top cover assembly provided in the embodiments of this application.

[0059] Figure 10 This is a side view of the pole post in the top cover assembly provided in the embodiments of this application.

[0060] Figure 11 This is a three-dimensional structural diagram of the pole post in the top cover assembly provided in another embodiment of this application.

[0061] Figure 12 This is a side view of the pole post in the top cover assembly provided in another embodiment of this application.

[0062] Figure 13 This is a three-dimensional structural diagram of the first insulating element in the top cover assembly provided in the embodiments of this application.

[0063] Figure 14 This is a cross-sectional view of the first insulating member in the top cover assembly provided in this application embodiment on a plane perpendicular to its length direction.

[0064] Figure 15 This is a cross-sectional view of the first insulating member in the top cover assembly provided in this application embodiment on a plane perpendicular to its width direction.

[0065] Figure 16 yes Figure 7 AA section view.

[0066] Figure 17 This is a three-dimensional structural diagram of the pole post in the top cover assembly provided in another embodiment of this application.

[0067] Figure 18 This is a side view of the pole post in the top cover assembly provided in another embodiment of this application.

[0068] Figure 19 This is a three-dimensional structural diagram of the first insulating member in the top cover assembly provided in another embodiment of this application.

[0069] Figure 20 This is a cross-sectional view of the first insulating member in the top cover assembly provided in another embodiment of this application on a plane perpendicular to its length direction.

[0070] Figure 21 This is a cross-sectional view of the first insulating member in the top cover assembly provided in another embodiment of this application on a plane perpendicular to its width direction.

[0071] Figure 22 This is a partial structural schematic diagram of the top cover sheet of the top cover assembly provided in the embodiments of this application.

[0072] Figure 23 This is a partial structural schematic diagram of the top cover sheet of the top cover assembly provided in the embodiments of this application.

[0073] Figure 24 This is a three-dimensional structural diagram of a battery cell provided in another embodiment of this application.

[0074] Figure 25 This is a front view structural schematic diagram of a battery cell provided in another embodiment of this application.

[0075] Figure 26 yes Figure 25 CC cross-section view.

[0076] Figure 27 This is a three-dimensional structural schematic diagram of the top cover assembly provided in another embodiment of this application.

[0077] Figure 28 This is an exploded structural diagram of the top cover assembly provided in another embodiment of this application.

[0078] Figure 29 This is a side view of a top cover assembly provided in another embodiment of this application.

[0079] Figure 30 yes Figure 29 CC cross-section view.

[0080] Figure 31 This is a side view of the pole post in the top cover assembly provided in another embodiment of this application.

[0081] Figure 32 This is a cross-sectional view of a top cover assembly provided in another embodiment of this application.

[0082] Figure 33 This is a cross-sectional view of a top cover assembly provided in another embodiment of this application.

[0083] Figure 34 This is a cross-sectional view of a top cover assembly provided in another embodiment of this application.

[0084] Figure 35 This is a cross-sectional view of a top cover assembly provided in another embodiment of this application.

[0085] In the diagram: 10-Top cover plate; 11-First surface; 12-Second surface; 13-First through hole; 14-Second groove; 15-Support part; 16-Notch; 20-Pole post; 21-First connecting part; 22-Second connecting part; 23-Flanged part; 24-First groove; 25-Transition part; 30-First insulating part; 31-First insulating part; 32-Second insulating part; 33-Third insulating part; 40-Second insulating part; 41-Second through hole; 43-Second inclined structure; 50-Pressure relief mechanism; 60-Protective layer; 100-Top cover assembly; 101-First outer peripheral surface; 102-First electrical connection surface; 103-Fifth surface; 104-First stepped surface; 105-Third stepped surface; 151-Fourth surface ; 152-Sixth surface; 200-Shell; 201-Second outer peripheral surface; 202-Third surface; 203-Second stepped surface; 204-Second electrical connection surface; 205-Third sub-part; 206-Fourth sub-part; 211-Base part; 212-First electrical connection part; 240-Second electrical connection part; 251-First arc segment; 252-First straight segment; 253-Second arc segment; 221-First metal layer; 222-Second metal layer; 300-Electrode assembly; 301-Electrode tab; 311-First inclined structure; 331-First sub-insulator; 332-Second sub-insulator; 333-Third sub-insulator; 334-Fourth sub-insulator; 2121-First sub-part; 2122-Second sub-part. Detailed Implementation

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] In related technologies, a battery cell typically consists of a casing, an electrode assembly, and a top cover assembly. The top cover assembly typically consists of a top cover sheet, terminals, a first insulating element, a sealing ring, and a second insulating element. The first insulating element is located between the outer surface of the top cover sheet facing the casing and the terminals, insulating the outer surface of the top cover sheet and the terminals. The second insulating element is located on the inner surface of the top cover sheet facing the casing, insulating the inner surface of the top cover sheet and the electrode assembly. To achieve a seal, a sealing ring is fitted onto the terminals, pressing between the top cover sheet and the terminals. The terminals have three parts along the width of the top cover sheet: a first connecting portion in the middle and two second connecting portions on either side of the first connecting portion. The first connecting portion connects to the second connecting portions on either side. The first connecting portion is used for welding to electrical connectors, and the second connecting portions are used for welding to the tabs of the electrode assembly. Since both the first and second connecting portions have requirements for welding area, their dimensions along the width of the top cover sheet cannot be too small, otherwise it will affect the current-carrying capacity of the terminals. This necessitates considering the following dimensions simultaneously in the width direction of the top cover assembly: the dimension of the outer casing film folded at the edge of the top cover sheet to the edge of the first insulator, the compression dimension of the sealing ring in the width direction of the top cover sheet, the dimensions of the two second connecting parts, and the dimensions of the first connecting part. For battery cells with smaller thicknesses, such as those with a thickness of less than 45mm, the design space for the width of the top cover assembly is limited, which restricts the design dimensions of the terminals. This results in a smaller weldable area for the first and second connecting parts, leading to weaker current carrying capacity of the terminals, which is detrimental to improving the charging and discharging performance and safety performance of the battery.

[0091] Based on the above considerations, and in order to address the technical problem that the limited space in existing top cover assembly designs restricts the size of the terminal post design, thus hindering the improvement of battery performance, this application provides an electrical device, a battery, a battery cell, and a top cover assembly.

[0092] 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.

[0093] 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.

[0094] The aforementioned battery can be a battery pack or a battery module. When the battery is a battery pack, the battery pack specifically includes a battery management system (BMS) and multiple battery cells. Multiple battery cells can be electrically connected in series, parallel, or a combination of series and parallel connections, and communicate with the battery management system, which controls and monitors the operating status of each battery cell. Alternatively, multiple battery cells can first be combined with a module management system to form a battery module, and then these battery modules can be electrically connected in series, parallel, or a combination of series and parallel connections to form a battery pack together with the battery management system.

[0095] 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.

[0096] 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.

[0097] As one embodiment of a battery cell, please refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 as well as Figure 24 , Figure 25 and Figure 26 A battery cell refers to the smallest unit that makes up a battery. For example... Figure 3 and Figure 4 or Figure 26 As shown, the battery cell includes a housing 200, an electrode assembly 300, a top cover assembly 100, and other functional components. At least one end of the housing 200 has an opening, and the top cover assembly 100 covers the opening of the housing 200 to isolate the internal environment of the battery cell from the external environment. The housing 200 has a receiving cavity to accommodate the electrode assembly 300 within the receiving cavity. The housing 200 is a component used to cooperate with the top cover assembly 100 to form the internal environment of the battery cell, wherein the formed internal environment can accommodate the electrode assembly 300, electrolyte, and other components. The housing 200 and the top cover assembly 100 can be independent components. An opening can be provided on the housing 200, and the top cover assembly 100 closes the opening to form the internal environment of the battery cell. The housing 200 can have various shapes and sizes, such as cylindrical, cuboid, hexagonal prism, etc. Specifically, the shape of the housing 200 can be determined according to the specific shape and size of the electrode assembly 300. The shell 200 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.

[0098] As one embodiment of an electrode assembly, the electrode assembly 300 is a component in a battery cell that undergoes an electrochemical reaction with the electrolyte. The housing 200 may contain one or more electrode assemblies 300. The electrode assembly 300 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, disposed 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 of the main body. The electrode assembly 300 is covered with an insulating film to reduce the risk of short circuits.

[0099] In some embodiments, each electrode assembly 300 extends a positive electrode tab and a negative electrode tab to the end face of the top cover assembly 100, 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 20 to form a current loop.

[0100] In the embodiments of this application, such as Figure 3 and Figure 4 or Figure 26 As shown, the housing 200 includes two sets of electrode assemblies 300, each set of electrode assemblies 300 including one electrode assembly 300. The two sets of electrode assemblies 300 are arranged side by side along the thickness direction of the housing 200. The two sets of positive electrode tabs of the two sets of electrode assemblies 300 are arranged opposite each other as positive electrodes, and the two sets of negative electrode tabs of the two sets of electrode assemblies 300 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 200. In some other embodiments, the housing 200 may include at least two sets of electrode assemblies 300. Each set of electrode assemblies 300 may be one electrode assembly 300 or multiple electrode assemblies 300, which is not limited here. When each set of electrode assemblies 300 includes multiple electrode assemblies 300, the positive electrode tabs of each electrode assembly 300 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.

[0101] It should be noted that the length direction of the housing 200 is also the length direction of the top cover assembly 100 or the length direction of the electrode assembly 300, the thickness direction of the housing 200 is also the width direction of the top cover assembly 100 or the thickness direction of the electrode assembly 300, and the height direction of the housing 200 is also the height direction of the electrode assembly 300 or the thickness direction of the top cover sheet 10.

[0102] Before the electrode assembly 300 is installed into the housing 200, the electrode tabs 301 of the electrode assembly 300 are first assembled with the top cover assembly 100, for example, by welding the electrode post 20 of the top cover assembly 100 to the electrode tabs 301 of the electrode assembly 300, and then the electrode assembly 300 is installed into the housing 200.

[0103] The structure of the top cover assembly 100 is described below.

[0104] Please refer to Figure 5 and Figure 6 or Figure 27 and Figure 28 The top cover assembly 100 includes a top cover sheet 10, which covers the opening of the housing 200. The shape of the top cover sheet 10 can be adapted to the shape of the housing 200 to fit the opening. The top cover sheet 10 can be made of a material with a certain hardness and strength (such as aluminum alloy or aluminum), so that the top cover sheet 10 is not easily deformed under pressure or impact, enabling the battery cell to have higher structural strength and improved safety performance. The material of the top cover sheet 10 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this.

[0105] Please refer to Figure 5 , Figure 6 , Figure 22 , Figure 23 or Figure 28 The top cover plate 10 has a first surface 11, a second surface 12, and a first through hole 13. The first surface 11 and the second surface 12 are arranged opposite to each other along the thickness direction of the top cover plate 10, and the first through hole 13 penetrates through both the first surface 11 and the second surface 12. The first surface 11 can be the surface of the top cover plate 10 facing the outside of the housing 200, and the second surface 12 can be the surface of the top cover plate 10 facing the inside of the housing 200. The first through hole 13 is used to install functional components, such as pole posts.

[0106] In some embodiments, such as Figure 8 , Figure 16 or Figure 30As shown, the width of the top cover plate 10 is W1, satisfying: W1 ≥ 20mm. For example, W1 can be within multiple ranges such as 20mm ≤ W1 ≤ 45mm, 20mm ≤ W1 ≤ 60mm, etc. Specifically, the width W1 of the top cover plate 10 can be 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, or 60mm, etc., including but not limited to the listed values, and other values ​​between any two of the above still apply. The width of the top cover plate 10 can be understood as the distance between two sides along the width direction of the top cover plate 10, which is used for welding connection with the housing 200. The top cover plate 10 of this embodiment can be applied to the housing 200 of a corresponding thickness and cover the opening of the housing 200.

[0107] like Figure 8 , Figure 16 or Figure 30 As shown, along the thickness direction of the top cover sheet 10, the thickness of the top cover sheet 10 is T2, satisfying: 1.5mm ≤ T2 ≤ 3mm. For example, T2 can be located in multiple intervals such as 1.8mm ≤ T2 ≤ 2.5mm, 1.5mm ≤ T2 ≤ 2mm, and 2mm ≤ T2 ≤ 3mm. Specifically, T2 can be 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, or 3.0mm, including but not limited to the listed values. Other values ​​between any two of the above still apply. The thickness of the top cover sheet 10 can be understood as the distance between the first surface 11 and the second surface 12 of the top cover sheet 10. By setting the thickness of the top cover sheet 10 within the above-mentioned range, the top cover sheet 10 has a certain hardness and strength, making it less prone to deformation when subjected to compression and impact, while improving the space utilization rate of the battery cell.

[0108] The top cover plate 10 may be provided with functional components such as pole post 20, first insulating member 30, second insulating member 40, and pressure relief mechanism 50. The top cover plate 10 and the functional components such as pole post 20, first insulating member 30, second insulating member 40 and pressure relief mechanism 50 provided on the top cover plate 10 together constitute the top cover assembly 100.

[0109] The terminal 20 can be electrically connected to the electrode assembly 300 for outputting or inputting electrical energy into the battery cell. The terminal 20 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 200 or leading it out to the exterior of the housing 200. 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 200 or leading it out to the exterior of the housing 200. The positive and negative terminals of adjacent battery cells can be electrically connected in series, parallel, or in a mixed configuration using electrical connectors.

[0110] It should be noted that the "terminal 20" mentioned in this application can be either a positive terminal or a negative terminal (unless otherwise specified). The "tab 301" mentioned in this application can be either a positive tab 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.

[0111] For details, please refer to Figure 9 , Figure 11 or Figure 17 The pole post 20 includes at least one first connecting portion 21 and at least two second connecting portions 22. The first connecting portion 21 is disposed on the side of the top cover plate 10 having a first surface 11, so that the first connecting portion 21 can be connected to an electrical connector. At least a portion of the second connecting portion 22 passes through the first through hole 13, so that the second connecting portion 22 can be connected to the tab 301.

[0112] It is understood that the number of second connecting parts 22 is not limited to two, but can also be three, four or more. The number of second connecting parts 22 can correspond to the number of electrode assemblies 300 within the housing 200, so that each second connecting part 22 is respectively connected to a set of electrode tabs 301.

[0113] When the number of electrode assemblies 300 disposed within the housing 200 is N, the number of second connecting portions 22 is also set to N, where N is an integer greater than 1. The N second connecting portions 22 are spaced apart along the width direction of the top cover plate 10 and are connected to the first connecting portions 21. The N second connecting portions 22 pass through the first through hole 13 and are correspondingly connected to the tabs 301 of each group of electrode assemblies 300.

[0114] The second connecting part 22 in this embodiment can be directly welded to the tab 301. Therefore, at least a portion of the second connecting part 22 passes through the first through hole 13 and extends into the housing 200 to be directly connected to the tab 301. No adapter structure is required, which reduces the use of components, 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.

[0115] In some other embodiments, the number of first connecting portions 21 is not limited to one, but can be two or more. The number of first connecting portions 21 is related to the number of second connecting portions 22. A first connecting portion 21 is provided between two adjacent second connecting portions 22. For example, when the number of second connecting portions 22 is 2, the number of first connecting portions 21 is 1. When the number of second connecting portions 22 is 3, the number of first connecting portions 21 is 2. When the number of second connecting portions 22 is 4, the number of first connecting portions 21 is 3, and so on. The second connecting portions 22 and the first connecting portions 21 are arranged alternately along the width direction of the top cover plate 10. For example, when the number of second connecting portions 22 is 3 and the number of first connecting portions 21 is 2, the pole post 20 includes, along the thickness direction of the top cover plate 10, a second connecting portion 22, a first connecting portion 21, a second connecting portion 22, a first connecting portion 21, and a second connecting portion 22 connected in sequence.

[0116] In this embodiment, two sets of electrode assemblies 300 are provided inside the housing 200, and each set of electrode assemblies 300 includes one electrode assembly 300. Since two electrode assemblies 300 can be provided inside the housing 200 along the thickness direction, the two electrode assemblies 300 can extend positive electrode tabs and negative electrode tabs at the same end. The two sets of positive electrode tabs 301 are arranged at intervals along the thickness direction of the electrode assembly 300, which is also the width direction of the top cover assembly 100. The two sets of negative electrode tabs 301 are arranged at intervals along the thickness direction of the electrode assembly 300. The two sets of positive electrode tabs and the two sets of negative electrode tabs are arranged at intervals along the length direction of the electrode assembly 300. Therefore, each pole post 20 is provided with two second connecting parts 22 and one first connecting part 21. The two second connecting parts 22 are arranged at intervals along the width direction of the top cover plate 10 so as to be directly connected to each set of pole tabs 301. One first connecting part 21 is connected to the adjacent second connecting parts 22 on both sides along the width direction of the top cover plate 10 so as to output the current drawn from the two second connecting parts 22 through one first connecting part 21. Compared with each second connecting part 22 corresponding to one first connecting part 21, the size and space occupied by the pole post 20 can be greatly reduced, saving materials and costs, and also facilitating processing.

[0117] like Figure 6 or Figure 28 As shown, the top cover plate 10 may have a first through hole 13 corresponding to each second connecting part 22, so that each second connecting part 22 passes through the first through hole 13 and is connected to the corresponding tab 301. It can be understood that the number of first through holes 13 may be the same as the number of second connecting parts 22. In other embodiments, the size of the first through hole 13 may also allow two second connecting parts 22 to pass through.

[0118] Please refer to Figure 9 , Figure 10 and Figure 11As one embodiment of the pole post 20, the first connecting portion 21 of the pole post 20 includes a base portion 211 and a first electrical connection portion 212, which are integrally formed. The base portion 211 and the first electrical connection portion 212 are stacked along the thickness direction of the first connecting portion 21, and the cross-sectional area of ​​the base portion 211 is larger than the cross-sectional area of ​​the first electrical connection portion 212. The thickness direction of the first connecting portion 21 is consistent with the thickness direction of the top cover plate 10. The first electrical connection portion 212 is located on the side of the base portion 211 facing the outside of the housing 200, and is used to connect with an electrical connector. The base portion 211 can be connected to the second connecting portion 22. The outer contour of the first connecting portion 21 has at least a first outer peripheral surface 101. Specifically, the first outer peripheral surface 101 is formed on the circumferential outer side surface of the base portion 211. When a portion of the circumferential outer side surface of the base portion 211 is flush with the circumferential outer side surface of the first electrical connection portion 212, that is, when they are the same outer side surface, the first outer peripheral surface 101 can also be the circumferential outer side surface of the first electrical connection portion 212. It is understood that the "circumferential" mentioned in the embodiments of this application can be the outer contour of the structural member on a plane perpendicular to the thickness direction of the pole post 20 or the top cover plate 10.

[0119] like Figure 9 and Figure 11 As shown, the first connecting portion 21 includes a first electrical connection surface 102 and a fifth surface 103 disposed opposite to the first electrical connection surface 102. The first electrical connection surface 102 is a welding surface for welding with an electrical connector, and the solder mark between the electrical connector and the first electrical connection surface 102 can extend from the first electrical connection surface 102 into the interior of the first electrical connection portion 212. The fifth surface 103 can be the surface of the base portion 211 facing the interior of the housing.

[0120] like Figure 9 and Figure 11 As shown, the first electrical connection portion 212 includes a first sub-portion 2121 and a second sub-portion 2122. Along the thickness direction of the top cover plate 10, one end of the first sub-portion 2121 is connected to the base portion 211, and the opposite end is connected to the second sub-portion 2122. It can be understood that the second sub-portion 2122 and the first sub-portion 2121 are stacked along the thickness direction of the top cover plate 10. Along the thickness direction of the top cover plate 10, the orthographic projection of the second sub-portion 2122 on the top cover plate 10 falls within the orthographic projection range of the first sub-portion 2121 on the top cover plate 10; that is, the cross-sectional area of ​​the second sub-portion 2122 is smaller than the cross-sectional area of ​​the first sub-portion 2121. Therefore, a first stepped surface 104 is connected between the sidewall surface of the first sub-portion 2121 and the sidewall surface of the second sub-portion 2122. The surface of the second sub-portion 2122 away from the first sub-portion 2121 is the first electrical connection surface 102.

[0121] The first stepped surface 104 is formed around the first electrical connection surface 102. Along the thickness direction of the first connection portion 21, the first electrical connection surface 102 protrudes from the first stepped surface 104; that is, the first stepped surface 104 is disposed closer to the base portion 211 than the first electrical connection surface 102. In this embodiment, as... Figure 9 , Figure 11 As shown, at least a third stepped surface 105 is formed around the first electrical connection portion 212 in the base portion 211. The third stepped surface 105 is formed between the side wall surface of the base portion 211 and the side wall surface of the first sub-part 2121 in the length direction of the base portion 211, which is also the length direction of the top cover plate 10. At this time, the first stepped surface 104 and the first electrical connection surface 102 both protrude from the third stepped surface 105.

[0122] The first stepped surface 104 creates a distance between the edge of the first insulating member 30 connected to the outside of the first sub-part 2121 and the first electrical connection surface 102, preventing interference with the first electrical connection surface 102 and thus avoiding affecting the welding quality between the first electrical connection surface 102 and the electrical connector. It is understood that during injection molding of the first insulating member 30, the first stepped surface 104 prevents plastic material from overflowing onto the first electrical connection surface 102 and affecting the welding quality.

[0123] As another embodiment of the first connecting portion 21 of the pole post 20, such as Figure 17 As shown, a first stepped surface 104 is formed between the side wall surface of the base portion 211 of the first connecting portion 21 of the pole post 20 and the side wall surface of the first electrical connecting portion 212. In this embodiment, the cross-sectional area of ​​the base portion 211 and the cross-sectional area of ​​the first sub-portion 2121 of the first electrical connecting portion 211 are the same along the thickness direction of the first connecting portion 21, therefore there is no third stepped surface 105 between the base portion 211 and the first sub-portion 2121.

[0124] In some embodiments, please refer to Figure 8 , Figure 12 , Figure 16 , Figure 18 or Figure 30Along the width direction of the top cover plate 10, the maximum width of the first connecting portion 21 is W2. The relationship between the maximum width W2 of the first connecting portion 21 and the width W1 of the top cover plate 10 satisfies: 20% ≤ W2 / W1 ≤ 60%. For example, W2 / W1 can be located within multiple intervals such as 30% ≤ W2 / W1 ≤ 50%, 20% ≤ W2 / W1 ≤ 40%, 40% ≤ W2 / W1 ≤ 60%, 30% ≤ W2 / W1 ≤ 40%, and 40% ≤ W2 / W1 ≤ 50%. Specifically, W2 / W1 = 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, or 60%, etc., including but not limited to the values ​​listed above. Other values ​​between any two of the above two still apply. The maximum width W2 of the first connecting portion 21 refers to the distance between the opposite first outer peripheral surfaces 101 along its width direction, i.e., along the width direction of the top cover plate 10. This arrangement ensures that the first connecting part 21 has sufficient welding area, while also providing a certain amount of space for the welding area of ​​the second connecting part 22 and for the outer casing film to be folded from the edge of the top cover plate 10 to the edge of the first insulating member 30.

[0125] Along the width direction of the top cover plate 10, the maximum width of the first connecting portion 21 is W2, satisfying: 8mm≤W2≤35mm. For example, W2 can be located within multiple intervals such as 8mm≤W1≤25mm, 8mm≤W1≤15mm, 15mm≤W2≤25mm, 8mm≤W2≤20mm, 20mm≤W2≤35mm, 18mm≤W2≤22mm, etc. Specifically, W2 = 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 15mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 25mm, 27mm, 29mm, 30mm, 31mm, 32mm, 33mm, 34mm, or 35mm, including but not limited to the values ​​listed above. Other values ​​between any two of the above still apply. This arrangement ensures that the first connecting portion 21 has sufficient welding area.

[0126] Please refer to Figure 8 or Figure 16 or Figure 30Along the width direction of the top cover plate 10, the minimum distance between the first outer peripheral surface 101 of the first connecting portion 21 and the edge of the top cover plate 10 is W3. The relationship between W3 and the width W1 of the top cover plate 10 satisfies: 25% ≤ W3 / W1 ≤ 40%. For example, W3 / W1 can be located in multiple intervals such as 30% ≤ W3 / W1 ≤ 35%, 25% ≤ W3 / W1 ≤ 35%, 35% ≤ W3 / W1 ≤ 40%, etc. Specifically, W3 / W1 = 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, or 40%, including but not limited to the values ​​listed above. Other values ​​between any two of the above are still applicable. It is understood that the minimum distance between the first outer peripheral surface 101 of the first connecting portion 21 and the edge of the top cover plate 10 refers to the minimum value among the distances from any point on the first outer peripheral surface 101 of the first connecting portion 21 to the plane containing the edge of the top cover plate 10 along the width direction of the top cover plate 10. With this configuration, while ensuring that the first connecting portion 21 has sufficient welding area, sufficient space can be reserved in the width direction of the top cover plate 10 for the welding area of ​​the second connecting portion 22 and for the outer sheath of the housing to the edge of the first insulating member 30 at the edge of the top cover plate 10.

[0127] Understandably, the first electrical connection portion 212 may also omit the first stepped surface 104. When the first electrical connection portion 212 does not have the first stepped surface 104, the dimension of the first electrical connection portion 212 along the width direction of the top cover plate 10 is equal to the dimension of the first electrical connection surface 102 along the width direction of the top cover plate 10. That is, the entire surface of the first electrical connection portion 212 away from the base portion 211 serves as the first electrical connection surface 102. Figure 8 , Figure 12 In the illustrated embodiment, although the cross-sectional area of ​​the base portion 211 is larger than the cross-sectional area of ​​the first electrical connection portion 212, the maximum width of the first electrical connection portion 212 can be equal to the maximum width W2 of the first connection portion 21 in the width direction of the top cover plate 10.

[0128] As one embodiment of the first connecting portion 21 of the pole post 20, such as Figure 8As shown, along the thickness direction of the top cover plate 10, the orthographic projection of the first connecting portion 21 on the top cover plate 10 does not overlap with the first through hole 13, that is, the orthographic projection of the first connecting portion 21 on the top cover plate 10 does not fall into the first through hole 13. At this time, along the width direction of the top cover plate 10, the minimum distance between the first outer peripheral surface 101 and the hole wall of the first through hole 13 is W5, which satisfies: 0≤W5≤10mm. For example, W5 is located in multiple intervals such as 0≤W5≤6mm, 0≤W5≤4mm, etc. Specifically, W5 = 0mm, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm or 10mm, including but not limited to the values ​​listed above, and other values ​​between any two of the above still apply. It can be understood that the first outer peripheral surface 101 can be aligned with the hole wall of the first through hole 13, and the hole wall of the first through hole 13 can also protrude from the first outer peripheral surface 101. It is understood that the minimum distance between the first outer peripheral surface 101 and the wall of the first through hole 13 refers to the minimum value among the distances from any point on the first outer peripheral surface 101 to any point on the wall of the first through hole 13 along the width direction of the top cover plate 10. This setting ensures that the first connecting part 21 has sufficient welding area, while reducing the size of the first connecting part 21 in the width direction of the pole post 20.

[0129] As another embodiment of the first connecting portion 21 of the pole post 20, such as Figure 16 As shown, along the thickness direction of the top cover plate 10, the orthographic projection of the first connecting portion 21 on the top cover plate 10 partially overlaps with the first through hole 13, that is, the partial orthographic projection of the first connecting portion 21 on the top cover plate 10 falls into the first through hole 13. It can be understood that the first outer peripheral surface 101 of the first connecting portion 21 protrudes from the hole wall of the first through hole 13. At this time, along the width direction of the top cover plate 10, the distance between the first outer peripheral surface 101 and the hole wall of the first through hole 13 is W5, satisfying: 0≤W5≤10mm. For example, W5 can be located within multiple intervals such as 0≤W5≤6mm, 0≤W5≤4mm, etc. Specifically, W5 = 0mm, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, or 10mm, including but not limited to the values ​​listed above; other values ​​between any two of the above are still applicable. This configuration ensures that the first connecting part 21 has sufficient welding area, while reducing the size of the first connecting part 21 in the width direction of the pole post 20 to accommodate the top cover plate 10 with a smaller width.

[0130] As one embodiment of pole post 20, please refer to Figure 8 , Figure 9 , Figure 10 , Figure 11 and Figure 12The second connecting portion 22 of the pole post 20 has a first groove 24. Along the thickness direction of the top cover plate 10, the opening of the first groove 24 is formed on the surface of the second connecting portion 22 near the first connecting portion 21, that is, the opening of the first groove 24 is located on the side of the top cover plate 10 with the first surface 11. The opening of the first groove 24 can be located outside the first surface 11, that is, higher than the first surface 11. A second electrical connection portion 240 is formed on the bottom wall of the first groove 24 of the second connecting portion 22. The second electrical connection portion 240 is connected to the tab 301, thereby making the second connecting portion 22 form a hollow structure, reducing the overall weight of the pole post 20 and saving material. It should be noted that the groove depth of the first groove 24 needs to consider the welding penetration depth of the second electrical connection portion 240 and the tab 301, material utilization rate, and the space utilization rate inside the shell. While saving material, the welding quality of both needs to be guaranteed.

[0131] Please refer to Figure 8 Along the thickness direction of the top cover plate 10, the bottom surface of the first groove 24 is located between the first surface 11 and the second surface 12, thereby ensuring the welding depth between the second electrical connection part 240 and the tab 301, while saving the material of the pole 20 and improving the space utilization rate inside the battery cell.

[0132] Please refer to Figure 9 , Figure 10 , Figure 11 and Figure 12 In this embodiment, the second connecting portion 22 of the pole post 20 is provided with a flange portion 23 around the opening of the first groove 24. Along the thickness direction of the top cover plate 10, the flange portion 23 is located on the side of the top cover plate 10 with the first surface 11. It can be understood that the flange portion 23 is a bent structure extending around the opening of the first groove 24 in a direction away from the central axis of the first groove 24. Providing the flange portion 23 around the opening of the first groove 24 facilitates the upper and lower dies to press the pole post 20 through the flange portion 23 during the stamping of the second connecting portion 22 of the pole post 20, and makes it easier to draw the two second connecting portions 22 downward to form the first groove 24.

[0133] In some embodiments, please refer to Figure 8Along the width direction of the top cover plate 10, the minimum distance between the side wall of the flange portion 23 and the edge of the top cover plate 10 is W4, satisfying: 5% ≤ W4 / W1 ≤ 20%. For example, W4 / W1 can be located in multiple intervals such as 5% ≤ W4 / W1 ≤ 15%, 10% ≤ W4 / W1 ≤ 15%, 12% ≤ W4 / W1 ≤ 20%, etc. Specifically, W4 / W1 = 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%, including but not limited to the values ​​listed above, and other values ​​between any two of the above still apply. It is understandable that the minimum distance between the side wall of the flange 23 and the edge of the top cover plate 10 refers to the minimum distance from any point on the side wall of the flange 23 to the plane containing the edge of the top cover plate 10 along the width direction of the top cover plate 10. When the ratio of W4 / W1 is less than 5%, the side wall of the flange 23 is too close to the edge of the top cover plate 10, which will affect the size of the outer shell film at the edge of the top cover plate to the edge of the first insulating member 30. When the ratio of W4 / W1 is greater than 20%, the distance between the side wall of the flange 23 and the edge of the top cover plate 10 will be larger, which will compress the size of the second connecting part 22 and the first connecting part 21 along the width direction of the top cover plate 10, thereby reducing the weldable area of ​​the second connecting part 22 and the tab 301 and the weldable area of ​​the first connecting part 21 and the electrical connector.

[0134] In some embodiments, the minimum distance between the side wall of the flange 23 and the edge of the top cover 10 is W4, satisfying: 3mm≤W4≤10mm. For example, W4 can be within multiple ranges such as 5mm≤W4≤8mm, 3mm≤W4≤6mm, 6mm≤W4≤10mm, 7mm≤W4≤10mm, etc. Specifically, W4 = 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, or 10mm, including but not limited to the values ​​listed above, and other values ​​between any two of the above still apply. When W4 is less than 3mm, the side wall of the flange 23 is too close to the edge of the top cover plate 10, which will further affect the size of the outer shell film from the edge of the top cover plate to the edge of the first insulating member 30. When W4 is greater than 10mm, the size of the second connecting part 22 and the first connecting part 21 along the width direction of the top cover plate 10 is compressed, thereby reducing the weldable area of ​​the second connecting part 22 and the tab 301 as well as the weldable area of ​​the first connecting part 21 and the electrical connector.

[0135] In some embodiments, please refer to Figure 8Along the thickness direction of the top cover plate 10, at least a portion of the orthographic projection of the flange 23 falls on the top cover plate 10, that is, on a virtual plane perpendicular to the thickness direction of the top cover plate 10, the orthographic projection of the flange 23 overlaps with the orthographic projection of the top cover plate 10. It can be understood that, along the direction perpendicular to the thickness direction of the top cover plate 10, the edge of the flange 23 protrudes from the wall of the first through hole 13. With this configuration, if necessary, a sealing ring can be installed on the side of the flange 23 facing the inside of the housing. The sealing ring can be pressed under the flange 23 to further seal the space between the first through hole 13 and the second connecting portion 22.

[0136] Please refer to Figure 9 , Figure 10 , Figure 11 and Figure 12 The flange 23 can be directly connected to the first outer peripheral surface 101 of the base portion 211 of the first connecting portion 21, thereby eliminating the transition portion between the first connecting portion 21 and the second connecting portion 22. Compared with the prior art, when the maximum dimension of the pole post 20 along the width direction of the top cover plate 10 is fixed, more space is provided for the weldable area of ​​the first connecting portion 21 and the weldable area of ​​the second connecting portion 22.

[0137] Please refer to Figure 10 and Figure 12 The upper surface of the flange 23 is flush with the upper surface of the base 211, and the lower surface of the flange 23 is also flush with the lower surface of the base 211. The upper surface of the flange 23 can be the surface facing outwards from the housing, and the upper surface of the base 211 is the surface facing outwards from the housing, i.e., the third step surface 105. The lower surface of the flange 23 is the surface facing inwards from the housing. The lower surface of the base 211 is the surface facing inwards from the housing, i.e., the fifth surface 103. Since the upper and lower surfaces of the flange 23 and the base 211 are parallel, the thickness of the punched surface is uniform throughout when the pole post 20 is processed, and there is no height difference in the punched surface. The outermost contour of the pole post 20 can be punched out in the final step of stamping, resulting in fewer punching burrs.

[0138] The lower surface of the flange 23 is flush with the lower surface of the base 211, which also makes it easier to press it down from below during stamping. The upper and lower dies match, making it easier to draw out the first groove 24.

[0139] Please refer to Figure 8 , Figure 9 and Figure 10When the electrode post 20 is a negative electrode post, the second connecting portion 22 includes a first metal layer 221 and a second metal layer 222. The first metal layer 221 and the second metal layer 222 are stacked along the thickness direction of the second connecting portion 22, with the second metal layer 222 located on the side of the first metal layer 221 facing the interior of the housing. The first metal layer 221 can be connected to the first connecting portion 21 and is made of the same material, while the second metal layer 222 covers the outside of the first metal layer 221. The second metal layer 222 directly contacts the negative electrode tab for welding. More specifically, in this embodiment, the first metal layer 221 is an aluminum layer, and the second metal layer 222 is a copper layer. Since the material of the negative electrode tab of the electrode assembly is generally also copper, the second metal layer 222 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.

[0140] In some embodiments, at least a portion of the interface between the first metal layer 221 and the second metal layer 222 intersects with the sidewall surface of the flange 23. It is understood that the sidewall surface of the flange 23 refers to its circumferential side surface. Since the flange 23 is located on the side of the top cover 10 having the first surface 11, the interface between the first metal layer 221 and the second metal layer 222 can be located on the outside of the top cover 10, preventing the first metal layer 221, which is an aluminum layer, from contacting the electrolyte inside the casing and corroding, thereby affecting the safety performance of the battery cell.

[0141] As another embodiment of pole post 20, please refer to Figure 17 , Figure 18 or Figure 31 The second connecting portion 22 has a plate-like structure, and the second connecting portion 22 of the pole post 20 does not have the first groove 24. It should be noted that the plate-like structure of the second connecting portion 22 can be understood as maintaining a consistent thickness along both the length direction (i.e., the length direction of the top cover plate 10) and the width direction (i.e., the width direction of the top cover plate 10). This facilitates processing, provides more space for the welding area of ​​the first connecting portion 21, and further reduces the total width of the pole post 20. In other words, when the total width of the pole post 20 is constant, it can increase the weldable area of ​​either the first connecting portion 21 or the second connecting portion 22. The width direction of the pole post 20 is the same as the width direction of the top cover plate 10.

[0142] Please refer to Figure 16 , Figure 17 , Figure 18 or Figure 31 Along the thickness direction of the top cover plate 10, the second connecting part 22 has a third surface 202, which is the surface of the second connecting part 22 facing the outside of the housing, that is, the surface close to the first connecting part 21, and the third surface 202 has a continuous planar structure.

[0143] In some embodiments, such as Figure 16 As shown, the third surface 202 is located between the first surface 11 and the second surface 12. This arrangement ensures the welding depth between the second connecting part 22 and the tab 301, while saving material for the electrode post and improving the space utilization rate inside the battery cell.

[0144] In some other embodiments, such as Figure 30 As shown, the third surface 202 is flush with the first surface 11 of the top cover plate 10. With this arrangement, when the first insulating component 30 is injection molded, the third surface 202 and the first surface 11 are flush, resulting in more even force distribution during injection molding, a longer sealing path, and easier injection molding. After injection molding, the first insulating component 30 will also experience more even force distribution.

[0145] In some other embodiments, the third surface 202 may also protrude beyond the first surface 11 of the top cover plate 10. That is, in the battery cell, the third surface 202 of the second connecting portion 22 facing the outside of the housing is higher than the first surface 11 of the top cover plate 10 facing the outside of the housing.

[0146] like Figure 17 , Figure 18 or Figure 31 The outer contour of the second connecting portion 22 forms a second outer peripheral surface 201, which surrounds the third surface 202 and extends in a direction perpendicular to the third surface 202. The extension direction of the second outer peripheral surface 201 of the second connecting portion 22 can be the same as the extension direction of the first outer peripheral surface 101 of the first connecting portion 21, thereby reducing the distance between the first connecting portion 21 and the second connecting portion 22 and reducing the width dimension of the pole post 20. In other words, when the total width of the pole post 20 is constant, the weldable area of ​​the first connecting portion 21 or the weldable area of ​​the second connecting portion 22 can be increased. In addition, it is also beneficial to reduce the forming difficulty of the second connecting portion 22.

[0147] like Figure 11 , Figure 12 , Figure 18 or Figure 31As shown, in some embodiments, the second connecting portion 22 includes a third sub-portion 205 and a fourth sub-portion 206. Along the thickness direction of the top cover plate 10, and on a plane perpendicular to the thickness direction of the top cover plate 10, the orthographic projection of the fourth sub-portion 206 falls within the orthographic projection range of the third sub-portion 205. It can be understood that the cross-sectional area of ​​the fourth sub-portion 206 is smaller than the cross-sectional area of ​​the third sub-portion 205. A second stepped surface 203 connects the sidewall surface of the fourth sub-portion 206 and the sidewall surface of the third sub-portion 205. The end surface of the fourth sub-portion 206 away from the third sub-portion 205 is a second electrical connection surface 204. The second connecting portion 22 has a second stepped surface 203 and a second electrical connection surface 204 on the side that passes through the first through hole 13. The second electrical connection surface 204 protrudes from the second stepped surface 203, that is, the second stepped surface 203 is disposed closer to the electrode assembly 300 than the second electrical connection surface 204. The second electrical connection surface 204 is used to connect with the tab 301. The penetration depth of the tab 301 and the second electrical connection surface 204 extends from the tab 301 through the second electrical connection surface 204 toward the interior of the second connection portion 22. The second electrical connection surface 204 protrudes from the second stepped surface 203, which facilitates direct welding of the tab 301 to the second electrical connection surface 204, avoids interference and damage to the tab 301 from other components, and improves the safety of the battery cell. Understandably, the second connection portion 22 may also be without the second stepped surface 203. When the second connection portion 22 is not provided with the second stepped surface 203, the entire end face of the second connection portion 22 passing through the first through hole 13 serves as the second electrical connection surface 204.

[0148] As one embodiment of pole post 20, please refer to Figure 17 , Figure 18 or Figure 31 The electrode post 20 also includes a transition portion 25, which connects the first connecting portion 21 and the second connecting portion 22 along the width direction of the top cover plate 10. In this embodiment, by bending the transition portion 25, the first connecting portion 21, the second connecting portion 22, and the transition portion 25 can be directly formed, making processing convenient. At the same time, by connecting the transition portion 25 between the first connecting portion 21 and the second connecting portion 22 along the width direction of the top cover plate 10, the size occupied by the electrode post 20 in the width direction can be reduced, leaving more space for the welding surface width of the first connecting portion 21 and the welding surface width of the second connecting portion 22, thereby reducing the overall size of the electrode post 20 in the width direction, making it suitable for battery cells with limited space in the top cover assembly design. In addition, by reducing the size of the transition portion 25 along the length direction of the top cover plate 10 or thinning the thickness of the transition portion 25, the transition portion 25 can also act as a fuse. A fuse is a structural component that melts preferentially before the first connecting portion 21 and the second connecting portion 22 when thermal runaway occurs in the battery cell. In the event of thermal runaway within a single battery cell, the circuit can be promptly disconnected via the transition section 25.

[0149] like Figure 16 or Figure 30 As shown, at least a portion of the transition portion 25 is projected into the first through hole 13 along the thickness direction of the top cover plate 10. It can be understood that since at least a portion of the transition portion 25 is accommodated within the first through hole 13, the transition portion 25 will not occupy additional width dimensions in the width direction of the top cover plate 10, thereby reducing the total width of the pole post 20. In other words, when the total width of the pole post 20 is constant, the weldable area of ​​the first connecting portion 21 or the weldable area of ​​the second connecting portion 22 can be increased.

[0150] Specifically, such as Figure 23 As shown, the first through hole 13 of the top cover plate 10 has a notch 16 for accommodating the transition portion 25. The notch 16 can refer to an opening on the wall of the first through hole 13 on the side opposite to the edge of the top cover plate 10, corresponding to the position of the transition portion 25. In some embodiments, the notch 16 is provided on the support portion 15. This allows the portion where the projection of the transition portion 25 overlaps with that of the first through hole 13 to be accommodated in the notch 16, preventing the wall of the first through hole 13 from interfering with the transition portion 25.

[0151] To ensure that in the event of thermal runaway in a single battery cell, the transition portion 25 melts preferentially before the first connecting portion 21 and the second connecting portion 22, such as... Figure 17 or Figure 28 As shown, along the length of the top cover 10, the length of the transition portion 25 is less than the length of the first connecting portion 21 and less than the length of the second connecting portion 22. This ensures that the current-carrying area of ​​the transition portion 25 is smaller than that of the first connecting portion 21 and less than that of the second connecting portion 22. The current-carrying area of ​​the transition portion 25 refers to the surface area of ​​the transition portion 25 perpendicular to the current flow direction, which is also the minimum cross-sectional area of ​​the transition portion 25. The current-carrying areas of the first connecting portion 21 and the second connecting portion 22 refer to the surface areas of the first connecting portion 21 and the second connecting portion 22 perpendicular to the current flow direction, which is also the minimum cross-sectional area of ​​the first connecting portion 21 and the second connecting portion 22. Thus, in actual use, when a circuit malfunction occurs, due to the smaller current-carrying area of ​​the transition portion 25, the temperature rises faster at the transition portion 25, allowing it to melt quickly and thus promptly cut off the circuit, greatly improving battery safety.

[0152] It is understandable that the transition portion 25 can also reduce the current-carrying area by slotting, opening, and / or thinning, ensuring that the circuit can be cut off in time when the circuit is abnormal. The thinning structure can be a general reduction in the thickness of the transition portion 25, or a groove structure formed in a part of the transition portion 25 and partially thinning the transition portion 25.

[0153] To further reduce the size of the transition portion 25 in the width direction of the top cover plate 10, as one embodiment of the transition portion 25, such as... Figure 18As shown, one end of the transition portion 25 is connected to the side wall of the second connecting portion 22, and the other end of the transition portion 25 is connected to the first outer peripheral surface 101 of the first connecting portion 21. The transition portion 25 includes a first arc segment 251, a first straight segment 252, and a second arc segment 253. The first arc segment 251 can be a transition segment connecting the first straight segment 252 to the side wall of the second connecting portion 22, and the first straight segment 252 is parallel to the side wall of the second connecting portion 22. The second arc segment 253 can be a transition segment connecting the first straight segment 252 to the first outer peripheral surface 101 of the first connecting portion 21, thereby reducing the size of the transition portion 25 in the width direction of the top cover plate 10.

[0154] As another embodiment of the transition section 25, such as Figure 31 As shown, one end of the transition portion 25 is connected to the third surface 202 of the second connecting portion 22, and the other end of the transition portion 25 is connected to the first outer peripheral surface 101 of the first connecting portion 21. In this embodiment, the transition portion 25 may include at least a first arc segment 251 and a first straight segment 252, wherein the first arc segment 251 may be a transition segment connecting the first straight segment 252 and the third surface 202 of the second connecting portion 22, and the first straight segment 252 is parallel to the third surface 202, thereby reducing the size of the transition portion 25 in the width direction of the top cover plate 10.

[0155] As one embodiment of the top cover sheet 10, please refer to Figure 22 The top cover plate 10 has a second groove 14 on its first surface 11, which is recessed from the first surface 11 to the second surface 12. It is understood that the second groove 14 is located on the surface of the top cover plate 10 facing the outside of the housing. Since the number of first through holes 13 can be the same as the number of second connecting parts 22, each second connecting part 22 is respectively inserted into a first through hole 13. At least two second connecting parts 22 are respectively inserted into at least two first through holes 13. Each first through hole 13 penetrates the bottom wall of the second groove 14 along the thickness direction of the top cover plate 10. That is, at least two first through holes 13 are disposed in the second groove 14. For example, in this embodiment, two first through holes 13 are disposed in the second groove 14, with a gap between the hole wall of the first through hole 13 and the groove sidewall of the second groove 14, that is, the hole wall of the first through hole 13 and the groove sidewall of the second groove 14 are not aligned.

[0156] The second groove 14 reduces the distance between the first electrical connection surface 102 of the terminal post 20 facing the outside of the housing and the first surface 11 of the top cover plate 10, improving the battery space utilization. Furthermore, it also reduces the dimension of the terminal post 20 along the thickness direction of the top cover plate 10, i.e., reduces the height difference between the first electrical connection surface 102 of the terminal post 20 facing the outside of the housing and the second electrical connection surface 204 facing the inside of the housing, which helps to reduce the molding difficulty of the terminal post 20.

[0157] In some embodiments, such as Figure 8 As shown, along the thickness direction of the top cover plate 10, the groove depth of the second groove 14 is T1, satisfying: 0.3mm≤T1≤1.5mm. For example, T1 can be located within multiple ranges such as 0.3mm≤T1≤1.2mm, 0.3mm≤T1≤0.8mm, 0.4mm≤T1≤1mm, 0.4mm≤T1≤0.6mm, etc. Specifically, T1 = 0.3mm, 0.4mm, 0.5mm, 0.7mm, 0.8mm, 0.9mm, 1.1mm, 1.3mm, or 1.5mm, including but not limited to the values ​​listed above, and other values ​​between any two of the above still apply. The groove depth of the second groove 14 can be understood as the distance between the bottom wall of the second groove 14 and the first surface 11 of the top cover plate 10. Through the above configuration, on the one hand, the distance between the first electrical connection surface 102 of the electrode post 20 facing the outside of the housing and the first surface 11 of the top cover plate 10 can be reduced, and on the other hand, the bottom wall of the second groove 14 can provide some support for the electrode post 20. When the groove depth T1 of the second groove 14 is less than 0.3mm, the groove depth of the second groove 14 is relatively shallow, which will result in a larger distance between the first electrical connection surface 102 of the electrode post 20 facing the outside of the housing and the first surface 11 of the top cover plate 10, and the height of the electrode post 20 will be relatively high, which will occupy more height space of the battery and increase the molding difficulty of the electrode post 20. When the groove depth T1 of the second groove 14 is greater than 1.5mm, the groove depth T1 of the second groove 14 is relatively large, which will result in a thinner bottom of the second groove 14, which is not conducive to the strength of the top cover plate 10 and the stable fixation of the electrode post 20.

[0158] In some embodiments, such as Figure 8 As shown, along the thickness direction of the top cover plate 10, the groove depth of the second groove 14 is T1, and the thickness of the top cover plate 10 is T2, satisfying: 10% ≤ T1 / T2 ≤ 80%. For example, T1 / T2 can be located within multiple intervals such as 10% ≤ T1 / T2 ≤ 70%, 10% ≤ T1 / T2 ≤ 50%, 10% ≤ T1 / T2 ≤ 40%, 10% ≤ T1 / T2 ≤ 30%, 20% ≤ T1 / T2 ≤ 30%, etc. Specifically, T1 / T2 = 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or 80%, including but not limited to the values ​​listed above. Other values ​​between any two of the above still apply. The above settings allow the groove depth of the second groove 14 and the thickness of the top cover plate 10 to be set within a suitable ratio range, reducing the distance between the first electrical connection surface 102 of the terminal post 20 facing the outside of the housing and the first surface 11 of the top cover plate 10, improving the space utilization of the battery, reducing the height of the terminal post 20, reducing the molding difficulty of the terminal post 20, and ensuring the stability of the terminal post 20 after assembly.

[0159] like Figure 8 As shown, the distance between the fifth surface 103 of the first connecting part 21 and the bottom wall of the second groove 14 is W6, satisfying: 0.5mm≤W6≤1.2mm. For example, W6 can be located in multiple ranges such as 0.5mm≤W6≤1mm, 0.6mm≤W6≤0.9mm, etc. Specifically, W6 = 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, or 1.2mm, etc., including but not limited to the values ​​listed above. Other values ​​between any two of the above are still applicable. This arrangement allows for a gap between the fifth surface 103 of the first connecting part 21 facing the inside of the housing and the bottom of the second groove 14. This gap is used to fill part of the structure of the first insulating member 30 to insulate the first connecting part 21 and the top cover plate 10. The thickness of the portion of the first insulating member 30 filling this gap should not be too thick, as this would occupy height space, nor should it be too thin, as this would cause the filled first insulating member 30 to easily crack and shrink.

[0160] As another embodiment of the top cover sheet, please refer to Figure 23 Along the thickness direction of the top cover plate 10, a through hole is provided in the top cover plate 10. A support portion 15 is provided within the through hole. The two ends of the support portion 15, arranged opposite each other along its longitudinal direction, are respectively connected to the two side walls of the through hole, which are arranged opposite each other along the length direction of the top cover plate 10, thus dividing the through hole into two first through holes 13 spaced apart along the width direction of the top cover plate 10. The support portion 15 can be used to support the first connecting portion 21 of the first insulating member 30 and the terminal post 20. The surface of the support portion 15 facing the outside of the housing 200 is lower than the upper surface of the top cover plate 10. The upper surface of the top cover plate 10 refers to the side surface of the top cover plate 10 away from the interior of the housing 200. This arrangement reduces the distance between the welding surface of the terminal post 20 and the electrical connector and the upper surface of the top cover plate 10, improving the space utilization rate within the battery. Meanwhile, the support part 15 allows the second connecting part 22 of the pole post 20 to be closer to the inside of the housing 200, which can reduce the height of the pole post 20 and thus reduce the processing difficulty of the pole post 20.

[0161] like Figure 16 As shown, along the thickness direction of the top cover plate 10, the support portion 15 has a sixth surface 152 disposed opposite to the fourth surface 151. The sixth surface 152 faces the interior of the housing and can be flush with the second surface 12 of the top cover plate 10 to facilitate the processing of the top cover plate 10.

[0162] In some embodiments, such as Figure 16As shown, the distance between the fourth surface 151 of the support portion 15 and the first surface 11 is T3, satisfying 0.3mm≤T3≤1.5mm. For example, T3 can be located within multiple ranges such as 0.3mm≤T3≤1.2mm, 0.3mm≤T3≤0.8mm, 0.4mm≤T3≤1mm, and 0.4mm≤T3≤0.6mm. Specifically, T3 = 0.3mm, 0.4mm, 0.5mm, 0.7mm, 0.8mm, 0.9mm, 1.1mm, 1.3mm, or 1.5mm, including but not limited to the values ​​listed above. Other values ​​between any two of the above are still applicable. This arrangement can reduce the distance between the first electrical connection surface 102 of the pole post 20 facing the outside of the housing and the first surface 11 of the top cover plate 10, while the support portion 15 can provide certain support for the pole post 20. When T3 is less than 0.3mm, the distance between the fourth surface 151 and the first surface 11 of the support portion 15 is too small, resulting in a larger distance between the first electrical connection surface 102 of the terminal post 20 and the first surface 11 of the top cover plate 10. This leads to a higher height for the terminal post 20, increasing the difficulty of molding the terminal post 20 and occupying more height space in the battery. When T3 is greater than 1.5mm, the distance between the fourth surface 151 and the first surface 11 of the support portion 15 is too large, resulting in a thinner support portion 15. This is detrimental to the strength of the top cover plate 10 and the stable fixation of the terminal post 20.

[0163] Along the thickness direction of the top cover plate 10, the relationship between the thickness T2 of the top cover plate 10 and the distance T3 between the fourth surface 151 and the first surface 11 of the support portion 15 satisfies: 10% ≤ T3 / T2 ≤ 80%. For example, T3 / T2 can be located within multiple intervals such as 10% ≤ T3 / T2 ≤ 70%, 10% ≤ T3 / T2 ≤ 50%, 10% ≤ T3 / T2 ≤ 40%, 10% ≤ T3 / T2 ≤ 30%, 20% ≤ T3 / T2 ≤ 30%, etc. Specifically, T3 / T2 = 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or 80%, including but not limited to the values ​​listed above. Other values ​​between any two of the above still apply. By setting the above configuration, the thickness of the support portion 15 and the thickness of the top cover plate 10 are set within a suitable ratio range, thereby reducing the distance between the first electrical connection surface 102 of the terminal post 20 facing the outside of the housing and the first surface 11 of the top cover plate 10, improving the space utilization of the battery, reducing the height of the terminal post 20, thereby reducing the molding difficulty of the terminal post 20, and ensuring the stability of the terminal post 20 after assembly.

[0164] In some embodiments, such as Figure 8 or Figure 18As shown, the distance W6 between the fifth surface 103 of the first connecting portion 21 and the fourth surface 151 of the support portion 15 satisfies: 0.5mm ≤ W6 ≤ 1.2mm. For example, W6 can be located within multiple ranges such as 0.5mm ≤ W6 ≤ 1mm, 0.6mm ≤ W6 ≤ 0.9mm, etc. Specifically, W6 = 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, or 1.2mm, etc., including but not limited to the values ​​listed above. Other values ​​between any two of the above are still applicable. This arrangement allows for a gap between the fifth surface 103 of the first connecting portion 21 facing the interior of the housing and the fourth surface 151 of the support portion 15. This gap is used to fill part of the structure of the first insulating member 30 to insulate the first connecting portion 21 and the top cover plate 10. The thickness of the portion of the first insulating member 30 filling this gap should not be too thick, as this would occupy height space, nor should it be too thin, as this would cause the portion of the first insulating member 30 to easily crack and shrink.

[0165] Please refer to Figure 6 and Figure 28 The top cover plate 10 may also be provided with a first insulating member 30, which is fixedly connected to the pole post 20 and the top cover plate 10 to fix the pole post 20 on the top cover plate 10 and to isolate the pole post 20 and the top cover plate 10 to reduce the risk of short circuit. For example, the first insulating member 30 may be a plastic material, such as PP, PE, PPS, etc.

[0166] In the embodiments of this application, please refer to Figure 8 , Figure 13 , Figure 19 , Figure 28 and Figure 30The first insulating member 30 includes a first insulating portion 31, a second insulating portion 32, and a third insulating portion 33 connected together. The first insulating portion 31 is disposed on the side of the top cover plate 10 having the second surface 12. It is understood that the first insulating portion 31 is disposed between the side of the top cover plate 10 having the second surface 12 and the second connecting portion 22 to form an insulation, thus preventing the second connecting portion 22 from contacting and electrically connecting with the top cover plate 10. Along the thickness direction of the top cover plate 10, at least a portion of the orthographic projection of the first insulating portion 31 falls on the top cover plate 10, that is, on a virtual plane perpendicular to the thickness direction of the top cover plate 10, the orthographic projection of the first insulating portion 31 overlaps with the orthographic projection of the top cover plate 10. It is understood that at least a portion of the orthographic projection of the first insulating portion 31 falls on the solid structure of the top cover plate 10, which does not include the first through hole 13. That is, at least a portion of the orthographic projection of the first insulating part 31 on a dummy plane overlaps with the orthographic projection of the top cover plate 10 on the dummy plane. Thus, at least a portion of the first insulating part 31 bends toward the inner side of the top cover plate 10 below the hole wall of the first through hole 13 and connects or snaps with the lower surface of the top cover plate 10. This improves the fixing effect on the pole through the first insulating part 31. The lower surface of the insulating top cover plate 10 and the pole 20 also serve as a seal to prevent electrolyte from leaking out of the first through hole 13.

[0167] The second insulating part 32 is disposed between the wall of the first through hole 13 and the second connecting part 22 of the electrode post 20, so as to connect the second connecting part 22 and the wall of the first through hole 13 through the second insulating part 32 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 13. The second insulating part 32 can be in the form of a ring structure, with one end of the second insulating part 32 facing the inside of the housing connected to the first insulating part 31, and the other end of the second insulating part 32 facing the outside of the housing connected to the third insulating part 33.

[0168] The third insulating portion 33 is disposed on the side of the top cover plate 10 having the first surface 11, that is, the third insulating portion 33 is disposed on the outer side of the top cover plate 10. It can be understood that the third insulating portion 33 covers the pole portion located on the outer side of the top cover plate 10 to insulate the pole portion located on the first surface 11 of the top cover plate 10 and the top cover plate 10. Simultaneously, the third insulating portion 33 also serves a sealing function. The pole portion located on the first surface 11 of the top cover plate 10 includes a portion of the structure of the first connecting portion 21 and the second connecting portion 22. Along the thickness direction of the top cover plate 10, at least a portion of the orthographic projection of the third insulating portion 33 falls on the top cover plate 10, that is, on a virtual plane perpendicular to the thickness direction of the top cover plate 10, the orthographic projection of the third insulating portion 33 overlaps with the orthographic projection of the top cover plate 10. It can be understood that the outer contour edge of the third insulating portion 33 protrudes from the wall of the first through hole 13.

[0169] First, the first insulating part 31 and the second insulating part 32 are connected as one unit and are L-shaped as a whole, so that they can be engaged with the top cover plate 10, thereby improving the fixing effect on the pole post 20. Furthermore, when at least a part of the orthographic projection of the third insulating part 33 falls on the orthographic projection of the top cover plate 10, that is, when the orthographic projection of the third insulating part 33 and the top cover plate 10 overlap, the first insulating part 31 and the third insulating part 33 can jointly hold the top cover plate 10 from both sides in the thickness direction of the top cover plate 10, thereby further improving the fixing effect on the pole post 20. Secondly, the sealing ring structure in the top cover assembly of related technologies can be eliminated. This eliminates the size requirement of the sealing ring in the width direction of the top cover sheet 10. Therefore, only the dimensions of the outer casing film at the edge of the top cover sheet to the edge of the first insulating member 30, the dimensions of the two second connecting portions 22, and the dimensions of the first connecting portion 21 need to be considered. Even for thinner battery cells with limited design width, the weldable area of ​​the first connecting portion 21 and the second connecting portion 22 can be guaranteed, thus not affecting the battery's charge / discharge performance and safety performance. Finally, the second insulating portion 32 passes through the first through hole 13, preventing electrolyte leakage from the first through hole 13 due to compression failure of the sealing ring during long-term use. Furthermore, the first insulating portion 31, the second insulating portion 32, and the third insulating portion 33 are connected as a single unit, increasing the sealing path for sealing the hole wall of the first through hole 13, further preventing electrolyte leakage from the first through hole 13.

[0170] In this embodiment, the first insulating portion 31, the second insulating portion 32, and the third insulating portion 33 of the first insulating member 30 are integrally formed. Furthermore, the first insulating portion 31, the second insulating portion 32, and the third insulating portion 33 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 31, the second insulating portion 32, and the third insulating portion 33, 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 some other embodiments, the first insulating portion 31, the second insulating portion 32, and the third insulating portion 33 can also be formed separately first, and then connected by bonding, hot melting, or other methods. Of course, in other embodiments, only the second insulating portion 32 can be nano-injection molded. Alternatively, the first insulating portion 31 and the second insulating portion 32 can also be nano-injection molded.

[0171] Specifically, the surfaces of the top cover plate 10 that contact the first insulating portion 31 and the second insulating portion 32 are provided with first nanopores, and at least a portion of the first insulating portion 31 and the second insulating portion 32 are embedded in the first nanopores; this can increase the bonding force and sealing performance between the first insulating portion 31 and the second insulating portion 32 and the top cover plate 10. During the manufacturing process, a nanopore structure can be formed on the second surface 12 of the top cover plate 10 and the hole wall of the first through hole 13 by chemical etching, thereby increasing the contact surface area of ​​the first insulating portion 31, the second insulating portion 32 and the top cover plate 10, and improving the bonding force and sealing performance.

[0172] In some embodiments, the surfaces of the electrode post 20 that contact the first insulating portion 31 and the second insulating portion 32 are provided with second nanopores, and the first insulating portion 31 and the second insulating portion 32 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 22 of the electrode post 20 by chemical etching to increase the contact surface area with the first insulating portion 31 and the second insulating portion 32, thereby improving the bonding force and sealing performance between the first insulating portion 31 and the second insulating portion 32 and the electrode post 20.

[0173] In some embodiments, the surface of the top cover 10 that contacts the third insulating portion 33 is provided with a third nanopore, and at least a portion of the third insulating portion 33 is embedded in the third nanopore. During the manufacturing process, a nanopore structure can be formed on the first surface 11 of the top cover 10, the bottom of the second groove 14, or the fourth surface 151 of the support portion 15 by chemical etching, thereby increasing the contact surface area between the third insulating portion 33 and the top cover 10 and improving the bonding force and sealing performance between the third insulating portion 33 and the top cover 10.

[0174] In some embodiments, the surface of the pole post 20 in contact with the third insulating portion 33 is provided with a fourth nanopore, and at least a portion of the third insulating portion 33 is embedded in the fourth nanopore. During the manufacturing process, nanopore structures can be formed by chemical etching on the fifth surface 103 of the first connecting portion 21, the bottom and wall surfaces of the first groove 24 of the second connecting portion 22, the upper and lower surfaces of the flange portion 23 of the second connecting portion 22, and the circumferential side surfaces. Alternatively, in some other embodiments, nanopore structures can be formed by chemical etching on the fifth surface 103 of the first connecting portion 21, the upper and lower surfaces of the transition portion 25, and the third surface 202 of the second connecting portion 22, thereby increasing the contact surface area between the third insulating portion 33 and the pole post 20, and improving the bonding force and sealing performance between the third insulating portion 33 and the pole post 20.

[0175] In some embodiments, such as Figure 8 , Figure 16 or Figure 30As shown, the surface of the first insulating portion 31 facing the interior of the housing is planar. In some embodiments, the surface of the first insulating portion 31 facing the interior of the housing (i.e., the surface facing away from the top cover plate 10) is flush with the second stepped surface 203 of the second connecting portion 22, to avoid the first insulating portion 31 affecting the welding between the second electrical connection surface 204 of the second connecting portion 22 and the tab 301. In some embodiments, the circumferential outer edge of the first insulating portion 31 has a first inclined structure 311. This first inclined structure 311 is inclined from the side of the first insulating portion 31 that contacts the second surface 12 toward the surface of the first insulating portion 31 facing the interior of the housing. It can be understood that, along the width and length directions of the top cover plate 10, the size of the contact surface between the first insulating portion 31 and the second surface 12 is larger than the size of the surface of the first insulating portion 31 facing the interior of the housing, so that the first insulating portion 31 can abut against the second surface 12 of the top cover plate 10. Figure 8 , Figure 16 and Figure 30 Looking at these three cross-sectional views, the first inclined structure 311 and the second surface 12 are set at an obtuse angle.

[0176] In some embodiments, the third insulating portion 33 covers the surface of the pole post 20 located on the side of the first surface 11, and at least exposes the first electrical connection surface 102 of the first connecting portion 21. While ensuring that the third insulating portion 33 can cover the surface of the pole post 20 located on the first surface 11 to insulate it from the top cover plate 10, the first electrical connection surface 102 is exposed so that it can be connected to an electrical connector. When the second connecting portion 22 and the tab 301 are welded using a pressure welding method, the third insulating portion 33 can expose at least a portion of the upper surface of the second connecting portion 22 to facilitate electrical connection between the electrode of the pressure welding device and the second connecting portion 22. This upper surface refers to the surface of the second connecting portion 22 away from the interior of the housing.

[0177] As one embodiment of the third insulating part 33, combined with Figure 13 , Figure 14 and Figure 15 As shown, the third insulating portion 33 includes a first sub-insulating portion 331 and a second sub-insulating portion 332 covering the first connecting portion 21. The first sub-insulating portion 331 fills the space between the lower surface of the base portion 211 and the bottom of the second groove 14. The second sub-insulating portion 332 covers the circumferential sidewall of the base portion 211, the circumferential sidewall of the first electrical connecting portion 212, and the third stepped surface 105 formed by the circumferential sidewall of the base portion 211 and the circumferential sidewall of the first electrical connecting portion 212. The surface of the second sub-insulating portion 332 facing away from the housing is flush with the first stepped surface 104 to prevent the second sub-insulating portion 332 from interfering with the welding of the first electrical connecting surface 102 of the first connecting portion 21 to the electrical connector.

[0178] Combination Figure 13 , Figure 14 and Figure 15 As shown, the third insulating part 33 also includes a third sub-insulating part 333 covering the second connecting part 22. The third sub-insulating part 33 covers the lower surface of the flanged part 23 facing the inside of the housing, the circumferential side wall surface of the flanged part 23, and the upper surface of the flanged part 23 facing the outside of the housing. When the second connecting part 22 has a first groove 24, the third sub-insulating part 333 also covers the bottom surface and side surface of the first groove 24.

[0179] Combination Figure 19 , Figure 20 and Figure 21 As shown, in another embodiment of the third insulating portion 33, the third insulating portion 33 includes a first sub-insulating portion 331 and a second sub-insulating portion 332. The first sub-insulating portion 331 fills the space between the lower surface of the base portion 211 and the fourth surface 151 of the support portion 15. The second sub-insulating portion 332 covers the circumferential sidewall surface of the base portion 211. The surface of the second sub-insulating portion 332 facing away from the housing is flush with the first stepped surface 104 to avoid interference between the second sub-insulating portion 332 and the welding of the first electrical connection surface 102 of the first connecting portion 21 and the electrical connector.

[0180] The third insulating part 33 also includes a third sub-insulating part 333 covering the second connecting part 22. When the second connecting part 22 is not provided with the flange 23 and the first groove 24, that is, the third surface 202 of the second connecting part 22 is a continuous planar structure, in this embodiment, the third sub-insulating part 333 can cover the edge of the third surface 202 and the edge of the first through hole 13 along the edge of the third surface 202.

[0181] When the pole post 20 also includes the transition section 25, such as Figure 19 and Figure 20 As shown, the third insulating part 33 also includes a fourth sub-insulating part 334, which covers the inner surface of the transition part 25 facing the inside of the housing and the outer surface facing the outside of the housing.

[0182] In some embodiments, the outer circumferential edge of the third insulating portion 33 is set at an obtuse angle to the first surface 11 of the top cover plate 10. It is understood that the outer circumferential edge of the third insulating portion 33 may be the portion of the third insulating portion 33 covering the side surfaces of the first connecting portion 21 and the second connecting portion 22. By setting the outer circumferential edge of the third insulating portion 33 at an obtuse angle to the first surface 11 of the top cover plate 10, the thickness of the third insulating portion 33 of the first insulating member 30 along the width direction of the top cover plate 10 can be appropriately reduced, while the draft angle formed by the obtuse angle facilitates smooth demolding of the mold.

[0183] In some embodiments, such as Figure 8As shown, when the first surface 11 of the top cover plate 10 is provided with the second groove 14, the distance between the outer circumferential edge of the third insulating part 33 and the groove wall of the second groove 14 is 'a', satisfying: 0.3mm ≤ a ≤ 2mm. For example, 'a' can be located within multiple ranges such as 0.3mm ≤ a ≤ 1.5mm, 0.3mm ≤ a ≤ 1mm, 0.3mm ≤ a ≤ 0.8mm, etc. Specifically, 'a' = 0.3mm, 0.5mm, 0.7mm, 0.9mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, or 2.0mm, including but not limited to the values ​​listed above. Other values ​​between any two of the above are still applicable. Through the above arrangement, the third insulating part 33 can be sealed on the outside of the groove wall of the second groove 14, and the outer circumferential edge of the third insulating part 33 is not too close to the edge of the top cover plate 10. When a is less than 0.3 mm, errors in manufacturing and mold positioning may cause the outer circumferential edge of the third insulating part 33 to shift into the second groove 14, exposing the second groove 14 and affecting the sealing performance. When a is greater than 2 mm, the outer circumferential edge of the third insulating part 33 is too close to the edge of the top cover plate 10. During the welding of the top cover plate 10 to the housing, the first insulating component 30 will be melted and blackened, affecting the insulation and sealing performance of the first insulating component 30.

[0184] As another embodiment of the first insulating element 30 in this application, such as Figure 32 and Figure 33As shown, the first insulating member 30 may include a second insulating portion 32 and a third insulating portion 33. That is, in this embodiment, the first insulating member 30 does not include a first insulating portion 31. In this case, the second insulating portion 32 is disposed between the wall of the first through hole 13 and the second connecting portion 22 of the electrode post 20, so as to connect the second connecting portion 22 and the wall of the first through hole 13 through the second insulating portion 32 and form insulation, while also serving a sealing function to prevent electrolyte leakage from the first through hole 13. The second insulating portion 32 may be annular, with one end of the second insulating portion 32 facing the outside of the housing connected to the third insulating portion 33. The third insulating portion 33 is disposed on the side of the top cover plate 10 having the first surface 11, that is, the third insulating portion 33 is disposed on the outside of the top cover plate 10. It can be understood that the third insulating portion 33 covers the electrode post portion located on the outside of the top cover plate 10, so as to insulate the electrode post portion located on the first surface 11 of the top cover plate 10 and the top cover plate 10, while also serving a sealing function. The electrode portion located on the first surface 11 of the top cover plate 10 includes a partial structure of a first connecting portion 21 and a second connecting portion 22. Along the thickness direction of the top cover plate 10, at least a portion of the orthographic projection of the third insulating portion 33 falls on the top cover plate 10; that is, on a dummy plane perpendicular to the thickness direction of the top cover plate 10, the orthographic projection of the third insulating portion 33 overlaps with the orthographic projection of the top cover plate 10. It is understood that the outer contour edge of the third insulating portion 33 protrudes beyond the wall of the first through hole 13. The second insulating portion 32 and the third insulating portion 33 can be integrally nano-injection molded. This can greatly improve the sealing performance of the battery cell, thus eliminating the need for the existing sealing ring structure. For other technical details in this embodiment, such as the cooperation relationship between the second insulating portion 32 and the third insulating portion 33 and the electrode 20 / top cover plate 10, please refer to the content of the foregoing embodiments.

[0185] As another embodiment of the first insulating element 30 in this application, such as Figure 34 and Figure 35As shown, the first insulating member 30 may further include a first insulating portion 31, a second insulating portion 32, and a third insulating portion 33 connected together. In this embodiment, the second insulating portion 32 is disposed between the wall of the first through hole 13 and the second connecting portion 22 of the electrode post 20, so as to connect the second connecting portion 22 and the wall of the first through hole 13 through the second insulating portion 32 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 13. The second insulating portion 32 may be in a ring structure, with one end of the second insulating portion 32 facing the inside of the housing connected to the first insulating portion 31, and the other end of the second insulating portion 32 facing the outside of the housing connected to the third insulating portion 33. In this embodiment, the first insulating part 31 is located on one side of the second surface 12 of the top cover plate 10, and along the thickness direction of the top cover plate 10, the orthographic projection of the first insulating part 31 falls entirely into the first through hole 13. That is, the first insulating part 31 extends from the end connected to the second insulating part 32 along the thickness direction of the top cover plate 10, and its orthographic projection does not fall on the top cover plate 10.

[0186] The third insulating portion 33 is disposed on the side of the top cover plate 10 having the first surface 11, that is, the third insulating portion 33 is disposed on the outer side of the top cover plate 10. It can be understood that the third insulating portion 33 covers the pole portion located on the outer side of the top cover plate 10, so as to insulate the pole portion located on the first surface 11 of the top cover plate 10 and the top cover plate 10. At the same time, the third insulating portion 33 can also serve as a seal. The pole portion located on the first surface 11 of the top cover plate 10 includes a portion of the structure of the first connecting portion 21 and the second connecting portion 22. Along the thickness direction of the top cover plate 10, at least a portion of the orthographic projection of the third insulating portion 33 falls on the top cover plate 10, that is, on a virtual plane perpendicular to the thickness direction of the top cover plate 10, the orthographic projection of the third insulating portion 33 overlaps with the orthographic projection of the top cover plate 10. It can be understood that the outer contour edge of the third insulating portion 33 protrudes from the hole wall of the first through hole 13. The first insulating portion 31, the second insulating portion 32 and the third insulating portion 33 can be integrally nano-injection molded. This can greatly improve the sealing performance of the battery cell. For other technical details in this embodiment, such as the cooperation relationship between the second insulating portion 32 and the third insulating portion 33 and the terminal post 20 / top cover plate 10, please refer to the content of the foregoing embodiments.

[0187] As one embodiment of the top cover assembly, please refer to Figure 6 and Figure 28 The top cover plate 10 may also be provided with a second insulating member 40, which is disposed on the second surface 12 of the top cover plate 10 and is used to insulate the top cover plate 10 and the electrode assembly 300 to reduce the risk of short circuit; for example, the second insulating member 40 may be a plastic material, such as PP, PE, PPS, etc.

[0188] Specifically, the second insulating member 40 is provided with a second through hole 41 corresponding to the first through hole 13. The second through hole 41 penetrates the thickness direction of the second insulating member 40. The second connecting part 22 passes through the first through hole 13 and the second through hole 41 in sequence so that the second connecting part 22 can be welded to the tab 301.

[0189] As one embodiment of the second insulating element 40, please refer to Figure 8 , Figure 16 , Figure 30 The second insulating member 40 has a second inclined structure 43 that matches the first inclined structure 311, and the second inclined structure 43 abuts against the first inclined structure 311. This allows the second insulating member 40 to engage with the first insulating member 30, increasing the connection reliability between the first insulating member 40 and the top cover plate 10, further improving the fixing effect on the electrode post 20, and facilitating the second insulating member 40 to insulate the top cover plate 10 and the electrode assembly 300, thus preventing the second insulating member 40 from affecting the sealing performance of the first insulating member 30 and the performance of other structural components.

[0190] In some embodiments, such as Figure 30 As shown, the surface of the second insulating member 40 facing away from the top cover plate 10 is flush with the surface of the first insulating portion 31 facing away from the top cover plate 10. That is, the surface of the second insulating member 40 facing the interior of the housing is flush with the surface of the first insulating portion 31 facing the interior of the housing. This arrangement ensures a smooth surface for easy fixture pressing when the second insulating member 40 is heat-fused and fixed to the top cover plate 10. In other embodiments, such as... Figure 16 or Figures 32 to 34 The second insulating member 40 can also extend to the second stepped surface 203 of the second connecting part 22. In this case, the second insulating member 40 covers the circumferential outer edge and bottom surface of the first insulating part 31. With this arrangement, the second insulating member 40 covers the contact interface between the first insulating part 31 and the top cover plate 10, preventing electrolyte from flowing into the first through hole 13 from the contact interface.

[0191] Please refer to Figure 6 The top cover plate 10 may also be provided with a pressure relief mechanism 50 for releasing internal pressure when the internal pressure or temperature of the battery cell reaches a threshold. The surface of the pressure relief mechanism 50 facing the outer side of the casing is provided with a protective layer 60 to protect the pressure relief mechanism 50. By providing a pressure relief mechanism 50 on the top cover plate 10, it is less likely for the battery cell to experience thermal runaway.

[0192] 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. A top cover assembly, characterized in that, include: The top cover plate (10) has a first surface (11), a second surface (12) and a first through hole (13), wherein the first surface (11) and the second surface (12) are arranged opposite to each other, and the first through hole (13) passes through the first surface (11) and the second surface (12); The pole post (20) includes at least one first connecting part (21) and at least two second connecting parts (22), and each first connecting part (21) is connected to two adjacent second connecting parts (22). The at least two second connecting parts (22) are arranged at intervals along the width direction of the top cover plate (10). The first connecting part (21) is provided on the side of the top cover plate (10) having the first surface (11) for connecting with an electrical connector. At least a portion of the second connecting part (22) passes through the first through hole (13) for connecting with a tab. The first insulating member (30) is fixedly connected to the pole post (20) and the top cover plate (10), and includes a second insulating part (32) and a third insulating part (33) connected to each other. The second insulating part (32) is disposed between the hole wall of the first through hole (13) and the second connecting part (22) of the pole post (20), and the third insulating part (33) is disposed on the side of the top cover plate (10) having a first surface (11).

2. The roof assembly of claim 1, wherein, The second connecting part (22) has a first groove (24) along the thickness direction of the top cover plate (10). The groove of the first groove (24) is formed on the surface of the second connecting part (22) near the first connecting part (21). The bottom surface of the first groove (24) is located between the first surface (11) and the second surface (12).

3. The roof assembly of claim 2, wherein, The second connecting part (22) has a flange (23) around the opening of the first groove (24). Along the thickness direction of the top cover plate (10), the flange (23) is located on the side of the top cover plate (10) having the first surface (11).

4. The roof assembly of claim 3, wherein, On a fictitious plane perpendicular to the thickness direction of the top cover (10), the orthographic projection of the flange (23) overlaps with the orthographic projection of the top cover (10).

5. The top cover assembly according to claim 3, characterized in that, The second connecting portion (22) includes a first metal layer (221) and a second metal layer (222). The first metal layer (221) and the second metal layer (222) are stacked along the thickness direction of the second connecting portion (22). At least a portion of the interface between the first metal layer (221) and the second metal layer (222) intersects with the side wall surface of the flange portion (23).

6. The roof assembly of claim 3, wherein, Along the width direction of the top cover plate (10), the width of the top cover plate (10) is W1, and the minimum distance between the side wall of the flange (23) and the edge of the top cover plate (10) is W4, satisfying: 5% ≤ W4 / W1 ≤ 20%; and / or, Satisfying: 3mm ≤ W4 ≤ 10mm; and / or, Satisfies: W1≥20mm.

7. The top cover assembly according to claim 1, characterized in that, The second connecting part (22) is a plate-shaped structure. Along the thickness direction of the top cover plate (10), the second connecting part (22) has a third surface (202) disposed near the first connecting part (21). The third surface (202) is located between the first surface (11) and the second surface (12).

8. The top cover assembly according to claim 7, characterized in that, The pole post (20) also includes a transition portion (25) along the width direction of the top cover plate (10), the transition portion (25) is connected between the first connecting portion (21) and the second connecting portion (22), and at least a portion of the transition portion (25) is projected into the first through hole (13) along the thickness direction of the top cover plate (10).

9. The top cover assembly according to claim 8, characterized in that, Along the length direction of the top cover (10), the length of the transition portion (25) is less than the length of the first connecting portion (21) and less than the length of the second connecting portion (22); the first through hole (13) has a notch (16) for accommodating the transition portion (25).

10. The top cover assembly according to claim 1, characterized in that, The second connecting part (22) is a plate-shaped structure. Along the thickness direction of the top cover plate (10), the second connecting part (22) has a third surface (202) disposed near the first connecting part (21). The third surface (202) is flush with the first surface (11) of the top cover plate (10), or the third surface (202) protrudes from the first surface (11) of the top cover plate (10).

11. The roof assembly of any one of claims 1 to 10, wherein, The surfaces of the top cover (10) that contact the second insulating portion (32) are each provided with a first nanopore, and at least a portion of the second insulating portion (32) is embedded in the first nanopore; and / or, The surfaces of the pole post (20) that are in contact with the second insulating part (32) are provided with second nanopores, and the second insulating part (32) is at least partially embedded in the second nanopores.

12. The top cover assembly according to claim 11, characterized in that, On a dummy plane perpendicular to the thickness direction of the top cover plate (10), the orthographic projection of the third insulating portion (33) overlaps with the orthographic projection of the top cover plate (10). A third nanopore is provided on the surface of the top cover plate (10) that contacts the third insulating portion (33), and at least a portion of the third insulating portion (33) is embedded in the third nanopore; and / or, The surface of the pole post (20) that contacts the third insulating part (33) is provided with a fourth nanopore, and at least a portion of the third insulating part (33) is embedded in the fourth nanopore.

13. The top cover assembly according to any one of claims 1 to 10, characterized in that, The second insulating portion (32) and the third insulating portion (33) of the first insulating member (30) are integrally formed.

14. The top cover assembly according to any one of claims 1 to 10, characterized in that, Along the thickness direction of the top cover plate (10), the orthographic projection of the first connecting portion (21) on the top cover plate (10) does not overlap with the first through hole (13). The outer contour of the first connecting portion (21) has at least a first outer peripheral surface (101). Along the width direction of the top cover plate (10), the minimum distance between the first outer peripheral surface (101) and the hole wall of the first through hole (13) is W5, satisfying: 0≤W5≤10mm; and / or, Along the thickness direction of the top cover plate (10), the orthographic projection of the first connecting part (21) on the top cover plate (10) partially overlaps with the first through hole (13). The outer contour of the first connecting part (21) has at least a first outer peripheral surface (101). Along the width direction of the top cover plate (10), the distance between the first outer peripheral surface (101) and the hole wall of the first through hole (13) is W5, which satisfies: 0≤W5≤10mm.

15. The top cover assembly according to any one of claims 1 to 10, characterized in that, The first surface (11) of the top cover plate (10) is provided with a second groove (14), which is recessed from the first surface (11) to the second surface (12). The top cover plate (10) includes at least two first through holes (13), and each second connecting part (22) is correspondingly inserted into one of the first through holes (13). The at least two first through holes (13) respectively penetrate the bottom wall of the second groove (14) along the thickness direction of the top cover plate (10).

16. The top cover assembly according to claim 15, characterized in that, Along the thickness direction of the top cover sheet (10), the thickness of the top cover sheet (10) is T2, satisfying: 1.5mm ≤ T2 ≤ 3mm; and / or, Along the thickness direction of the top cover plate (10), the groove depth of the second groove (14) is T1, satisfying: 0.3mm ≤ T1 ≤ 1.5mm; and / or, Along the thickness direction of the top cover (10), the groove depth of the second groove (14) is T1, and the thickness of the top cover (10) is T2, satisfying: 10% ≤ T1 / T2 ≤ 80%.

17. The top cover assembly according to any one of claims 1 to 10, characterized in that, Along the thickness direction of the top cover plate (10), the top cover plate (10) is provided with a through hole, and a support part (15) is provided in the through hole. The two ends of the support part (15) arranged opposite to each other along its longitudinal direction are respectively connected to the two side hole walls of the through hole arranged opposite to each other along the length direction of the top cover plate (10), and the through hole is divided into two first through holes (13) spaced apart along the width direction of the top cover plate (10). Along the thickness direction of the top cover plate (10), the first surface (11) of the top cover plate (10) protrudes from the support part (15).

18. The top cover assembly according to claim 17, characterized in that, Along the thickness direction of the top cover plate (10), the support portion (15) has a fourth surface (151) close to the first surface (11); the distance between the fourth surface (151) of the support portion (15) and the first surface (11) is T3, satisfying: 0.3mm ≤ T3 ≤ 1.5mm; and / or, Along the thickness direction of the top cover (10), the thickness of the top cover (10) is T2, and the distance between the fourth surface (151) of the support (15) and the first surface (11) is T3, satisfying: 10% ≤ T3 / T2 ≤ 80%.

19. The top cover assembly according to any one of claims 1 to 10, characterized in that, Along the thickness direction of the top cover plate (10), the surface of the first connecting portion (21) near the top cover plate (10) is the fifth surface (103). The first surface (11) of the top cover plate (10) is provided with a second groove (14). The distance between the fifth surface (103) and the bottom wall of the second groove (14) is W6, satisfying: 0.5mm≤W6≤1.2mm; or, Along the thickness direction of the top cover plate (10), the top cover plate (10) is provided with a through hole, and a support part (15) is provided in the through hole. The two ends of the support part (15) arranged opposite to each other along its longitudinal direction are respectively connected to the two side hole walls of the through hole arranged opposite to each other along the length direction of the top cover plate (10), and the through hole is divided into two first through holes (13) spaced apart along the width direction of the top cover plate (10). The side surface of the support part (15) near the first connecting part (21) is the fourth surface (151). The distance between the fifth surface (103) and the fourth surface (151) of the support part (15) is W6, which satisfies: 0.5mm≤W6≤1.2mm; and / or, Along the width direction of the top cover plate (10), the maximum width of the first connecting portion (21) is W2, and the width W1 of the top cover plate (10) satisfies: 20% ≤ W2 / W1 ≤ 60%; and / or, Along the width direction of the top cover plate (10), the maximum width of the first connecting portion (21) is W2, satisfying: 8mm ≤ W2 ≤ 35mm; and / or, Along the width direction of the top cover plate (10), the width of the top cover plate (10) is W1, satisfying: W1≥20mm; and / or, The outer contour of the first connecting part (21) has at least a first outer peripheral surface (101). Along the width direction of the top cover (10), the minimum distance between the first outer peripheral surface (101) and the edge of the top cover (10) is W3, and the width of the top cover (10) is W1, satisfying: 25% ≤ W3 / W1 ≤ 40%.

20. The top cover assembly according to any one of claims 1 to 10, characterized in that, The third insulating portion (33) covers the surface of the pole (20) located on the side of the first surface (11) and exposes at least the first electrical connection surface (102) of the first connection portion (21).

21. The roof assembly of claim 20, wherein, The outer edge of the third insulating part (33) is set at an obtuse angle to the first surface (11) of the top cover plate (10).

22. The top cover assembly according to claim 20, characterized in that, The first surface (11) of the top cover plate (10) is provided with a second groove (14), and the distance between the outer edge of the third insulating part (33) and the groove sidewall of the second groove (14) is a, which satisfies: 0.3mm≤a≤2mm.

23. The roof assembly of any one of claims 1 to 10, wherein, Also includes: The second insulating member (40) is provided on one side of the top cover plate (10) having a second surface (12). The second insulating member (40) has a second through hole (41) corresponding to the first through hole (13). The second through hole (41) penetrates the thickness direction of the second insulating member (40). The second connecting part (22) passes through the first through hole (13) and the second through hole (41) in sequence.

24. The roof assembly of any one of claims 1 to 10, wherein, The first insulating member (30) also includes a first insulating part (31) connected to the second insulating part (32), the first insulating part (31) being disposed on the side of the top cover plate (10) having the second surface (12).

25. The roof assembly of claim 24, wherein, On a fictitious plane perpendicular to the thickness direction of the top cover plate (10), the orthographic projection of the first insulating part (31) overlaps with the orthographic projection of the top cover plate (10); or, along the thickness direction of the top cover plate (10), the orthographic projection of the first insulating part (31) falls entirely into the first through hole (13).

26. The roof assembly of claim 25, wherein, The second connecting part (22) includes a third sub-part (205) and a fourth sub-part (206). Along the thickness direction of the top cover plate (10) and on a plane perpendicular to the thickness direction of the top cover plate (10), the orthographic projection of the fourth sub-part (206) falls within the orthographic projection range of the third sub-part (205). A second stepped surface (203) is connected between the side wall surface of the fourth sub-part (206) and the side wall surface of the third sub-part (205). The end surface of the fourth sub-part (206) away from the third sub-part (205) is a second electrical connection surface (204). The second step surface (203) is flush with the surface of the first insulating part (31) that is away from the top cover plate (10).

27. A single battery cell, characterized in that, include: The housing (200) has an opening; An electrode assembly (300) having tabs (301) is received within the housing (200); The top cover assembly according to any one of claims 1 to 26 is disposed over the opening of the housing (200).

28. A battery, characterized in that, Includes the battery cell as described in claim 27.

29. An electrical appliance, characterized in that, Includes the battery cell of claim 27 or the battery of claim 28.

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