Top cover assembly, processing method, battery monomer, battery and power utilization device

Abstract

The invention provides a top cover assembly and a processing method, 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 plate, the top cover plate comprises a metal layer and an insulating layer along the thickness direction of the top cover plate, the insulating layer comprises a first insulating part and a second insulating part, the mechanical strength of the second insulating part is larger than that of the first insulating part, the second insulating part is provided with at least one first through hole penetrating through the thickness direction of the second insulating part, and at least part of the first insulating part is contained in the first through hole. Therefore, the overall strength of the top cover plate can be compensated through the second insulating part, and further the thickness of the metal layer is allowed to be reduced, so that the total thickness of the top cover plate is reduced, the space utilization rate of the internal height of the battery monomer is improved, and the top cover assembly has relatively good structural strength while realizing relatively high space utilization rate.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a top cover assembly and its processing method, a battery cell, a battery, and an electrical device. Background Technology

[0002] In the field of battery technology, continuously improving the energy density and space utilization of individual battery cells is one of the core development goals. In related technologies, the top cover assembly of a battery cell typically includes a top cover sheet and a lower plastic layer. The lower plastic layer is usually fixed below the top cover sheet by heat fusion and is used to insulate the top cover sheet and electrode assembly.

[0003] However, due to the relatively low strength of the lower plastic, the thickness of the top cover sheet is usually increased to ensure sufficient strength for the entire top cover assembly. Simultaneously, to prevent insulation failure in the lower plastic, its thickness is often designed to be relatively large. This setup results in a thicker overall top cover assembly, occupying a significant portion of the internal height space of the battery cells, thus affecting the space utilization rate within the battery cells. If the thickness of the top cover assembly is reduced to improve the space utilization rate in the height direction of the battery cells, the limited strength of the lower plastic means that only the thickness of the top cover sheet can be reduced. This, in turn, leads to poor overall strength of the top cover assembly. Summary of the Invention

[0004] The purpose of this application is to provide a top cover assembly and processing method, a battery cell, a battery, and an electrical device to solve the technical problem that the top cover assembly in the prior art cannot simultaneously achieve good strength and space utilization.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows: In a first aspect, this application provides a top cover assembly, including: a top cover plate, which includes a metal layer and an insulating layer along its thickness direction. The insulating layer includes a first insulating member and a second insulating member, wherein the mechanical strength of the second insulating member is greater than that of the first insulating member, and the second insulating member is provided with at least one first through hole penetrating its thickness direction, and at least a portion of the first insulating member is accommodated in the first through hole.

[0006] In one or more embodiments of this application, the side of the first insulating member facing the metal layer is connected to the metal layer.

[0007] In one or more embodiments of this application, the surface of the first insulating member facing the metal layer is flush with the surface of the second insulating member facing the metal layer, and the surface of the first insulating member away from the metal layer is flush with the surface of the second insulating member away from the metal layer.

[0008] In one or more embodiments of this application, on a virtual plane perpendicular to the thickness direction of the insulating layer, the projected area of ​​the solid portion of the second insulating member is larger than the projected area of ​​the solid portion of the first insulating member.

[0009] In one or more embodiments of this application, the second insulating member covers both ends of the first insulating member along its length direction; and the second insulating member covers both sides of the first insulating member along its width direction.

[0010] In one or more embodiments of this application, the second insulating member includes a first body and a boss, the boss being disposed at both ends of the first body along its length direction, and the boss protruding from the first body in a direction away from the metal layer.

[0011] In one or more embodiments of this application, the first insulating member at least covers both ends of the second insulating member along its length.

[0012] In one or more embodiments of this application, the first insulating member includes a second body and a boss, the boss being disposed at both ends of the second body along its length direction, and the boss protruding from the second body in a direction away from the metal layer.

[0013] In one or more embodiments of this application, the first insulating member covers both sides of the second insulating member along its width direction.

[0014] In one or more embodiments of this application, it further includes: The pole is fixed to the top cover plate; The third insulating component is fixed between the pole and the metal layer, wherein the insulating component and the first insulating component are integrally formed.

[0015] In one or more embodiments of this application, the third insulating member includes a first insulating portion and a second insulating portion, wherein the first insulating portion is disposed on the side of the metal layer away from the insulating layer, the metal layer is provided with a second through hole penetrating its thickness direction, and the second insulating portion is disposed between the hole wall of the second through hole and the pole post, wherein the first insulating portion, the second insulating portion and the first insulating member are integrally formed.

[0016] In one or more embodiments of this application, the second insulating member is further provided with a third through hole extending through its thickness direction. On a dummy plane perpendicular to the thickness direction of the top cover plate, the orthographic projection of the third through hole covers the orthographic projection of the second through hole. At least a portion of the first insulating member is disposed in the third through hole around the hole wall of the third through hole and connected to the metal layer.

[0017] In one or more embodiments of this application, the central axis of the third through hole is aligned with the central axis of the second through hole, and the diameter of the second through hole is smaller than the diameter of the third through hole.

[0018] In one or more embodiments of this application, at least a portion of the first through hole on the second insulating member is arranged in an arc around the third through hole in the circumferential direction and is connected to the third through hole.

[0019] In one or more embodiments of this application, it further includes: The pole is fixed to the top cover plate; The third insulating component is fixed between the pole and the metal layer; A seal is located between the metal layer and the pole.

[0020] In one or more embodiments of this application, the third insulating member includes a first insulating portion and a second insulating portion, wherein the first insulating portion is disposed on the side of the metal layer away from the insulating layer, the metal layer is provided with a second through hole penetrating its thickness direction, the second insulating portion is disposed between the hole wall of the second through hole and the pole post, wherein the second insulating portion, the pole post and the first insulating member surround to form a receiving cavity, and a sealing member is disposed in the receiving cavity.

[0021] In one or more embodiments of this application, the metal layer, the first insulating element, and the second insulating element are an integral structure.

[0022] In one or more embodiments of this application, the metal layer has a first nanopore on the surface in contact with the first insulating member, and at least a portion of the first insulating member is embedded in the first nanopore and connected to the metal layer; and / or, The second insulating member has a second nanopore on its surface in contact with the first insulating member, and at least a portion of the first insulating member is embedded in the second nanopore and connected to the second insulating member.

[0023] In one or more embodiments of this application, the connection area between the first insulating element and the metal layer is S4, satisfying: 300mm² 2 ≤S4≤15000mm 2 ; and / or, On a virtual plane perpendicular to the thickness direction of the top cover plate, the area of ​​the orthographic projection region of the outer contour of the metal layer is S5, satisfying: 1300mm². 2 ≤S5≤20000mm 2 ; and / or, Satisfying: 20% ≤ S4 / S5 ≤ 75%; and / or, Along the thickness direction of the top cover plate, the thickness of the metal layer is 'a', satisfying: 0.1mm ≤ a ≤ 1.5mm; and / or, Along the thickness direction of the top cover plate, the thickness of the metal layer is a, and the total thickness of the top cover plate is b, satisfying: 5%≤a / b≤60%.

[0024] In one or more embodiments of this application, the first through hole is elongated and / or arc-shaped; and / or, The first through hole is arranged on the second insulating element along its length and / or along its width; and / or, The total area of ​​the first through hole is S1. On a hypothetical plane perpendicular to the thickness direction of the top cover plate, the area of ​​the orthographic projection region of the outer contour of the second insulating component is S2, satisfying: 10% ≤ S1 / S2 ≤ 70%; and / or, The metal layer is provided with a first liquid injection hole, and the second insulating element is provided with a second liquid injection hole corresponding to the first liquid injection hole; and / or, The metal layer is equipped with a pressure relief mechanism, and the second insulating component is equipped with an exhaust port corresponding to the pressure relief mechanism.

[0025] Secondly, this application provides a battery cell including the top cover assembly described in any of the first aspects.

[0026] Thirdly, this application provides a battery, including the battery cell described in the second aspect.

[0027] Fourthly, this application provides an electrical device, including the battery cell described in the second aspect, or the battery described in the third aspect.

[0028] Fifthly, this application provides a method for processing a top cover assembly, comprising the following steps: Position the second insulating component and the metal layer so that the central axis of the third through hole of the second insulating component is aligned with the central axis of the second through hole of the metal layer. The first insulating element is injection molded onto the surface of the metal layer, and at least a portion of the first insulating element is embedded in the first through hole of the second insulating element and connected to the metal layer.

[0029] In one or more embodiments of this application, it further includes: A first nanopore is pre-formed on the surface of the metal layer that contacts the first insulating element, and at least a portion of the first insulating element is embedded in the first nanopore and connected to the metal layer during injection molding; and / or, A second nanopore is pre-formed on the surface of the second insulator that contacts the first insulator, and at least a portion of the first insulator is embedded in the second nanopore and connected to the second insulator during injection molding.

[0030] Based on the above technical solutions, the top cover assembly and processing method, battery cell, battery, and power device of this application have at least the following beneficial technical effects: In the top cover assembly of this application embodiment, the top cover plate includes a metal layer and an insulating layer along its thickness direction. The insulating layer includes a first insulating member and a second insulating member, wherein the mechanical strength of the second insulating member is greater than that of the first insulating member. This allows the second insulating member to compensate for the overall strength of the top cover plate, thereby allowing for a reduction in the thickness of the metal layer. This not only reduces the total thickness of the top cover plate and improves the space utilization rate of the battery cell's internal height, but also enables the top cover assembly to achieve high space utilization while possessing good structural strength. Because the overall strength of the top cover plate is improved, it is less prone to deformation during use, enhancing the safety performance of the battery cell. Simultaneously, the second insulating member has at least one first through-hole penetrating its thickness direction, with at least a portion of the first insulating member accommodated within the first through-hole. This enhances the bonding force between the first and second insulating members, improves the connection reliability of the top cover plate, and allows the top cover plate to form a single integral structure. Attached Figure Description

[0031] 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.

[0032] Figure 1 This is an exploded disassembly diagram of the top cover plate in the top cover assembly provided in this application embodiment.

[0033] Figure 2 This is a schematic diagram of the explosive decomposition of the insulating layer in the top cover plate of the top cover assembly provided in this application embodiment.

[0034] Figure 3 This is a schematic diagram of the bottom view of the insulating layer in the top cover plate of the top cover assembly provided in this application embodiment.

[0035] Figure 4 This is a schematic diagram of the installation structure of the third insulating element, insulating layer and pole in the top cover plate of the top cover assembly provided in the embodiments of this application.

[0036] Figure 5 This is a top view structural diagram of the top cover plate in the top cover assembly provided in the embodiments of this application.

[0037] Figure 6 yes Figure 5 BB cross-section diagram.

[0038] Figure 7 This is an exploded disassembly diagram of the top cover plate in a top cover assembly provided in another embodiment of this application.

[0039] Figure 8This is a schematic diagram of the explosive decomposition of the insulating layer in the top cover plate of the top cover assembly provided in another embodiment of this application.

[0040] Figure 9 This is a top view of the top cover plate in another embodiment of the top cover assembly provided in this application.

[0041] Figure 10 yes Figure 9 AA section view.

[0042] Figure 11 This is an exploded disassembly diagram of the top cover plate in a top cover assembly provided in another embodiment of this application.

[0043] Figure 12 This is a top view schematic diagram of the top cover plate in a top cover assembly provided in another embodiment of this application.

[0044] Figure 13 yes Figure 12 CC cross-section view.

[0045] Figure 14 This is a three-dimensional structural diagram of the metal layer in the top cover plate of the top cover assembly provided in this application embodiment.

[0046] Figure 15 This is a three-dimensional structural diagram of the third insulating element in the top cover plate of the top cover assembly provided in this application embodiment.

[0047] Figure 16 This is a three-dimensional structural diagram of the pole post in the top cover plate of the top cover assembly provided in the embodiments of this application.

[0048] Figure 17 This is a three-dimensional structural diagram of a battery cell provided in an embodiment of this application.

[0049] Figure 18 This is a schematic diagram of the explosive decomposition of a single battery cell provided in an embodiment of this application.

[0050] Figure 19 This is a schematic diagram of the explosion and decomposition of a battery provided in an embodiment of this application.

[0051] Figure 20 This is a schematic diagram of the structure of the electrical device provided in the embodiments of this application.

[0052] In the diagram: 1000 - Vehicle; 1100 - Battery; 1101 - Housing; 1 - Battery cell; 2 - First housing section; 3 - Second housing section; 10 - Top cover; 20 - Adapter; 30 - Electrode assembly; 40 - Housing; 50 - Insulating film; 301 - Positive electrode tab; 302 - Negative electrode tab; 11 - Metal layer; 12 - Insulating layer; 13 - Terminal post; 14 - Third insulating component; 15 - Protective film; 16 - Sealing component; 110 - First groove; 111 - Second through hole; 1 12-First injection hole; 113-Pressure relief mechanism; 114-Second groove; 120-First body; 121-First insulating component; 122-Second insulating component; 123-Boss; 124-Third through hole; 125-First through hole; 126-Second injection hole; 127-Vent hole; 128-Second body; 131-First connecting part; 132-Second connecting part; 133-Third groove; 141-First insulating part; 142-Second insulating part; 144-Snap-fit ​​part. Detailed Implementation

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] In related technologies, the top cover assembly of a battery cell typically includes a top cover sheet and a lower plastic layer. The lower plastic layer is usually fixed below the top cover sheet by heat fusion and is used to insulate the top cover sheet and electrode components. However, due to the relatively low strength of the lower plastic layer, the thickness of the top cover sheet is usually increased to ensure sufficient strength of the entire top cover assembly. Simultaneously, to prevent insulation failure of the lower plastic layer, its thickness is often designed to be relatively large. This configuration results in a thicker overall top cover assembly, occupying a significant portion of the internal height space of the battery cell, thus affecting the space utilization rate within the battery cell. If the thickness of the top cover assembly is reduced to improve the space utilization rate in the height direction of the battery cell, the limited strength of the lower plastic layer necessitates only reducing the thickness of the top cover sheet, which would lead to poor overall strength of the top cover assembly.

[0058] Based on the above considerations, in order to solve the technical problem that the top cover assembly in the prior art cannot simultaneously achieve good strength and space utilization, this application provides an electrical device, a battery, a battery cell, a top cover assembly, and a processing method.

[0059] 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.

[0060] This application describes an electrical device using a vehicle 1000 as an example. Figure 20 As shown, vehicle 1000 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 1100 is installed inside vehicle 1000, which can be located at the bottom, front, or rear of vehicle 1000. Battery 1100 can be used to power vehicle 1000; for example, it can serve as the operating power source for vehicle 1000. Vehicle 1000 may also include a controller and a motor. The controller is used to control the battery to power the motor, for example, to meet the power needs of vehicle 1000 during starting, navigation, and driving. The battery can not only serve as the operating power source for vehicle 1000 but also as its driving power source, replacing or partially replacing gasoline or natural gas to provide driving power for the vehicle.

[0061] As one embodiment of battery 1100, such as Figure 19 As shown, the battery 1100 includes a housing 1101 and a battery cell 1, with the battery cell 1 housed within the housing 1101. The housing 1101 provides a space for the battery cell 1 and can have various structures. In some embodiments, the housing 1101 may include a first housing portion 2 and a second housing portion 3, which overlap each other, together defining a space for accommodating the battery cell 1. The second housing portion 3 may be a hollow structure with one open end, and the first housing portion 2 may be a plate-like structure, with the first housing portion 2 covering the open side of the second housing portion 3 so that the first housing portion 2 and the second housing portion 3 together define the space. Alternatively, both the first housing portion 2 and the second housing portion 3 may be hollow structures with one open side, with the open side of the first housing portion 2 covering the open side of the second housing portion 3. Of course, the box 1101 formed by the first box part 2 and the second box part 3 can be of various shapes, such as a cylinder, a cuboid, etc.

[0062] The aforementioned battery 1100 can be a battery pack or a battery module. When the battery 1100 is a battery pack, the battery pack specifically includes a battery management system (BMS) and multiple battery cells 1. The multiple battery cells 1 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 1. Alternatively, the multiple battery cells 1 can first be combined with a module management system to form a battery module, and then the multiple battery modules can be electrically connected in series, parallel, or a combination of series and parallel connections to form a battery pack together with the battery management system.

[0063] Multiple battery cells 1 can be mounted on supporting structures such as housings, frames, and brackets. The individual battery cells 1 and the battery management system can be electrically connected via electrical connectors, which can be busbars. Alternatively, the individual battery cells can be electrically connected via 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, the battery cells and the battery management system can also be electrically connected via mutual insertion, which will not be elaborated further here.

[0064] The aforementioned battery cell 1 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.

[0065] As one embodiment of battery cell 1, battery cell 1 refers to the smallest unit that makes up the battery. Please refer to... Figure 17 and Figure 18 The battery cell 1 includes a housing 40, an electrode assembly 30, a top cover assembly, and other functional components. At least one end of the housing 40 has an opening, and the top cover assembly covers the opening of the housing 40 to isolate the internal environment of the battery cell from the external environment. The housing 40 has a receiving cavity to accommodate the electrode assembly 30 within the receiving cavity. The housing 40 is a component used to cooperate with the top cover assembly to form the internal environment of the battery cell, wherein the formed internal environment can accommodate the electrode assembly 30, electrolyte, and other components. The housing 40 and the top cover assembly can be independent components. An opening can be provided on the housing 40, and the top cover assembly closes the opening to form the internal environment of the battery cell. The housing 40 can have various shapes and sizes, such as cylindrical, cuboid, hexagonal prism, etc. Specifically, the shape of the housing 40 can be determined according to the specific shape and size of the electrode assembly 30. The material of the housing 40 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment does not impose any special limitations on this.

[0066] As one embodiment of the electrode assembly 30, the electrode assembly 30 is a component in a battery cell that undergoes an electrochemical reaction with the electrolyte. The housing 40 may contain one or more electrode assemblies 30. The electrode assembly 30 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 30 is covered with an insulating film 50 to reduce the risk of short circuits.

[0067] In some embodiments, each electrode assembly 30 extends a positive electrode tab 301 and a negative electrode tab 302 from its end face toward the top cover assembly. During the charging and discharging process of the battery, the positive and negative active materials react with the electrolyte, and the positive electrode tab 301 and negative electrode tab 302 are respectively connected to the terminal post 13 to form a current loop. Before the electrode assembly 30 is installed into the housing 40, the positive electrode tab 301 and negative electrode tab 302 of the electrode assembly 30 are first assembled with the top cover assembly, for example, by welding the terminal post 13 of the top cover assembly to the tab of the electrode assembly 30 through the adapter 20, and then the electrode assembly 30 is installed into the housing 40.

[0068] As one embodiment of the top cover assembly, please refer to Figures 1 to 6 or Figures 7 to 10 or Figures 11 to 13 The top cover assembly of this application embodiment includes a top cover plate 10, the shape of which can be adapted to the shape of the housing 40 to fit the opening of the housing 40. Along its thickness direction, the top cover plate 10 includes a metal layer 11 and an insulating layer 12. The metal layer 11 can be made of a metal material with a certain hardness and strength, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc. Figure 2 or Figure 8 As shown, the insulating layer 12 includes a first insulating element 121 and a second insulating element 122, wherein the mechanical strength of the second insulating element 122 is greater than that of the first insulating element 121. This means that when the second insulating element 122 is subjected to a certain force, its elastic deformation is smaller than that of the first insulating element 121; that is, the rigidity of the second insulating element 122 is better than that of the first insulating element 121. The first insulating element 121 can be made of plastic materials, such as PP, PE, or PPS. The second insulating element 122 can be made of a material with mechanical strength close to or even greater than that of the metal layer 11 and greater than that of the first insulating element 121, such as ceramic.

[0069] The second insulating element 122 compensates for the overall strength of the top cover plate 10, thereby allowing for a reduction in the thickness of the metal layer 11. This not only reduces the total thickness of the top cover plate 10 and improves the space utilization rate of the internal height of the battery cell 1, but also enables the top cover assembly to achieve high space utilization while possessing good structural strength. Because the overall strength of the top cover plate 10 is improved, it is less prone to deformation during use, enhancing the safety performance of the battery cell.

[0070] In some embodiments, please refer to Figure 6Along the thickness direction of the top cover plate 10, the thickness of the metal layer 11 is 'a', satisfying the condition: 0.1mm ≤ a ≤ 1.5mm. For example, 'a' can be located within multiple ranges such as 0.2mm ≤ a ≤ 1.5mm, 0.5mm ≤ a ≤ 1.5mm, 0.5mm ≤ a ≤ 1.2mm, 0.5mm ≤ a ≤ 1.0mm, and 0.8mm ≤ a ≤ 1.0mm. Specifically, 'a' can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, and 1.5mm, including but not limited to the listed values. Other values ​​between any two of the above are still applicable. This allows the metal layer 11 to have sufficient strength while making its thickness thinner than in the prior art, thereby improving the space utilization rate of the internal height of the battery cell. When a < 0.1 mm, the thickness of the metal layer 11 is too small, resulting in insufficient strength and consequently lower strength of the top cover plate 10. When a > 1.5 mm, the thickness of the metal layer 11 is too large, leading to a larger total thickness of the top cover plate 10. This occupies a significant portion of the internal height space of the battery cell, reducing the space utilization rate within the battery cell.

[0071] In some embodiments, please refer to Figure 6 Along the thickness direction of the top cover plate 10, the thickness of the metal layer 11 is 'a', and the total thickness of the top cover plate 10 is 'b', satisfying the condition: 5% ≤ a / b ≤ 60%. For example, a / b can fall within multiple ranges such as 5% ≤ a / b ≤ 55%, 10% ≤ a / b ≤ 55%, 15% ≤ a / b ≤ 50%, 20% ≤ a / b ≤ 45%, 25% ≤ a / b ≤ 40%, and 30% ≤ a / b ≤ 40%. Specifically, a / b can be 5%, 8%, 10%, 13%, 15%, 18%, 20%, 23%, 25%, 27%, 30%, 35%, 38%, 40%, 43%, 45%, 50%, 55%, 60%, etc., including but not limited to the listed values; other values ​​between any two of the above are still applicable. This configuration ensures that the top cover plate 10 has sufficient strength, while the total thickness of the top cover plate 10 is thinner than in the prior art, improving the space utilization rate of the internal height of the battery cell. When a / b < 5%, the thickness of the metal layer 11 is too small, resulting in low strength of the top cover plate 10. When a / b > 60%, the thickness of the metal layer 11 is too large, resulting in a large total thickness of the top cover plate 10, which occupies a large amount of internal height space of the battery cell and reduces the internal space utilization rate of the battery cell.

[0072] In some embodiments, please refer to Figure 2 or Figure 8The second insulating member 122 is provided with at least one first through hole 125 extending through its thickness direction. The number of first through holes 125 can be one, two, three, four, five, or even more. When there are multiple first through holes 125, they can be interconnected. At least a portion of the first insulating member 121 is accommodated in the first through hole 125. This enhances the bonding force between the first insulating member 121 and the second insulating member 122, improving the connection reliability of the insulating layer 12.

[0073] In some embodiments, please refer to Figure 5 , Figure 6 or Figure 9 , Figure 10 The first insulating member 121 is connected to the metal layer 11 on the side facing the metal layer 11. This can enhance the bonding force between the first insulating member 121 and the metal layer 11, as well as between the first insulating member 121 and the second insulating member 122, and improve the connection reliability between the metal layer 11 and the insulating layer 12, so that the top cover plate 10 forms an integral structure.

[0074] In some embodiments, please refer to Figure 1 , Figure 5 , Figure 6 or Figure 7 , Figure 9 , Figure 10 The surface of the first insulating member 121 facing the metal layer 11 is flush with the surface of the second insulating member 122 facing the metal layer 11, and the surface of the first insulating member 121 facing away from the metal layer 11 is flush with the surface of the second insulating member 122 facing away from the metal layer 11. It can be understood that the first insulating member 121 and the second insulating member 122 form an embedded structure, so that the first insulating member 121 and the second insulating member 122 form a layered insulating layer 12. This arrangement ensures that the total thickness of the top cover plate 10 is not excessive, while the second insulating member 122 can also compensate for the overall strength of the top cover plate 10, giving the top cover plate 10 sufficient strength and improving the space utilization rate of the internal height of the battery cell.

[0075] In some embodiments, please refer to the Figure 2 or Figure 8The first through hole 125 is elongated and / or arc-shaped. It is understood that when at least two first through holes 125 are provided on the second insulating member 122, the shapes of the first through holes 125 can all be elongated, all be arc-shaped, or a combination of both. In some embodiments, the first through holes 125 are arranged on the second insulating member 122 along its length direction and / or along its width direction. It is understood that when at least two first through holes 125 are provided on the second insulating member 122, adjacent first through holes 125 can be arranged along the length direction, along the width direction, or simultaneously along both directions, and adjacent first through holes 125 can be connected. This arrangement allows at least a portion of the first insulating member 121 to pass through the first through holes 125 and connect with the metal layer 11, improving the connection reliability between adjacent layers and facilitating the forming of the first insulating member 121.

[0076] In some embodiments, please refer to the Figure 2 or Figure 8 On a virtual plane perpendicular to the thickness direction of the insulating layer 12, the projected area of ​​the solid portion of the second insulating member 122 is larger than the projected area of ​​the solid portion of the first insulating member 121. It can be understood that the solid portion of the second insulating member 122 refers to the solid part of the second insulating member 122 excluding holes. The solid portion of the first insulating member 121 refers to the solid part of the first insulating member 121 excluding holes. Thus, the second insulating member 122 in the insulating layer 12 can be used to insulate the metal layer 11 and the electrode assembly 30, while the first insulating member 121, while insulating the metal layer 11 and the electrode assembly 30, can also be used to fix the second insulating member 122 and the metal layer 11.

[0077] In some embodiments, the total area of ​​the first through hole 125 is S1, and the area of ​​the orthographic projection region of the outer contour of the second insulating member 122 on a dummy plane perpendicular to the thickness direction of the top cover plate 10 is S2, satisfying: 10%≤S1 / S2≤70%; for example, S1 / S2 can be within multiple intervals such as 10%≤S1 / S2≤65%, 10%≤S1 / S2≤50%, 15%≤S1 / S2≤70%, 15%≤S1 / S2≤60%, 15%≤S1 / S2≤45%, 20%≤S1 / S2≤50%, 25%≤S1 / S2≤45%. Specifically, S1 / S2 can be 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, etc., including but not limited to the listed values, and other values ​​between any two of the above still apply. It is understandable that the total opening area of ​​the first through hole 125 refers to the sum of the areas of the cross-sections of all the first through holes 125 on the second insulating member 122 along the hole axis. This configuration ensures both the reliability of the connection between the metal layer 11, the first insulating member 121, and the second insulating member 122, and also guarantees the strength of the second insulating member 122. If S1 / S2 < 10%, the total opening area of ​​the first through hole 125 is too small, resulting in low reliability of the connection between the metal layer 11, the first insulating member 121, and the second insulating member 122. If S1 / S2 > 70%, the total opening area of ​​the first through hole 125 is too large, affecting the strength of the second insulating member 122 and thus reducing the strength of the top cover plate 10.

[0078] In some embodiments, the metal layer 11, the first insulating member 121, and the second insulating member 122 are integral structures. It is understood that the first insulating member 121 can be injection molded onto the metal layer 11 and the second insulating member 122 so that the metal layer 11, the first insulating member 121, and the second insulating member 122 are formed as a whole and can be used as a whole.

[0079] In some embodiments, the first insulating member 121 is nano-injection molded onto the second insulating member 122 and the metal layer 11. To achieve nano-injection molding of the first insulating member 121, the metal layer 11 has a first nanopore on its surface in contact with the first insulating member 121, and at least a portion of the first insulating member 121 is embedded in the first nanopore and connected to the metal layer 11. The second insulating member 122 has a second nanopore on its surface in contact with the first insulating member 121, and at least a portion of the first insulating member 121 is embedded in the second nanopore and connected to the second insulating member 122. This improves the bonding force between the first insulating member 121, the second insulating member 122, and the metal layer 11. During manufacturing, the surface treatment of the metal layer 11 and the second insulating member 122 can be chemically etched to form a nanopore structure, thereby increasing the connection area between the first insulating member 121 and the metal layer 11 and the second insulating member 122, and improving the bonding force between the first insulating member 121 and the metal layer 11 and the second insulating member 122.

[0080] In some embodiments, the area of ​​the connection surface between the first insulating member 121 and the metal layer 11 is S4, satisfying: 300mm² 2 ≤S4≤15000mm 2 For example: S4 can be located at 300mm. 2 ≤S4≤14000mm 2 400mm 2 ≤S4≤15000mm 2 500mm 2 ≤S4≤14000mm 2 600mm 2 ≤S4≤13000mm 2 700mm 2 ≤S4≤12000mm 2 800mm 2 ≤S4≤11000mm 2 900mm 2 ≤S4≤11000mm 2 1000mm 2 ≤S4≤10000mm 2 Within multiple intervals. Specifically, S4 can be 300mm. 2 800mm 2 1300mm 2 1800mm 2 2300mm 2 2800mm 2 3300mm 2 3800mm 2 3300mm 2 3800mm2 4300mm 2 4800mm 2 5300mm 2 5800mm 2 6300mm 2 6800mm 2 7300mm 2 7800mm 2 8300mm 2 8800mm 2 9300mm 2 9800mm 2 10300mm 2 10800mm 2 11300mm 2 11800mm 2 12300mm 2 12800mm 2 13300mm 2 13800mm 2 14300mm 2 14800mm 2 15000mm 2 And so on, including but not limited to the values ​​listed, other values ​​between any two of the above still apply. This arrangement can increase the connection reliability between the first insulating element 121 and the metal layer 11 when S4 < 300 mm. 2 The connection area between the first insulating element 121 and the metal layer 11 is too small, resulting in low reliability of the connection between the first insulating element 121 and the metal layer 11. When S4 > 15000 mm 2 If the connection area between the first insulating element 121 and the metal layer 11 is too large, it will cause the total opening area of ​​the first through hole 125 of the second insulating element 122 to be too large, which will affect the strength of the second insulating element 122.

[0081] In some embodiments, on a virtual plane perpendicular to the thickness direction of the top cover plate 10, the area of ​​the orthographic projection region of the outer contour of the metal layer 11 is S5, satisfying: 1300 mm². 2 ≤S5≤20000mm 2 For example: S5 can be located at 1300mm. 2 ≤S5≤15000mm 2 2000mm 2 ≤S5≤15000mm 2 3000mm 2 ≤S5≤14000mm 2 4000mm 2 ≤S5≤13000mm2 5000mm 2 ≤S5≤12000mm 2 6000mm 2 ≤S5≤11000mm 2 7000mm 2 ≤S5≤11000mm 2 8000mm 2 ≤S5≤10000mm 2 Within multiple ranges. Specifically, S5 can be 1300mm. 2 1800mm 2 2300mm 2 2800mm 2 3300mm 2 3800mm 2 3300mm 2 3800mm 2 4300mm 2 4800mm 2 5300mm 2 5800mm 2 6300mm 2 6800mm 2 7300mm 2 7800mm 2 8300mm 2 8800mm 2 9300mm 2 9800mm 2 10300mm 2 10800mm 2 11300mm 2 11800mm 2 12300mm 2 12800mm 2 13300mm 2 13800mm 2 14300mm 2 14800mm 2 15000mm 2 15800mm 2 16300mm 2 17800mm 2 18800mm 2 19800mm 2 20000mm 2And so on, including but not limited to the values ​​listed, other values ​​between any two of the above still apply. In this way, the metal layer 11 can have sufficient strength.

[0082] In some embodiments, the connection area between the first insulating member 121 and the metal layer 11 is S4, and the area of ​​the orthographic projection region of the outer contour of the metal layer 11 on a dummy plane perpendicular to the thickness direction of the top cover plate 10 is S5, satisfying: 20% ≤ S4 / S5 ≤ 75%. For example, S4 / S5 can be located within multiple intervals such as 20% ≤ S4 / S5 ≤ 70%, 30% ≤ S4 / S5 ≤ 65%, 35% ≤ S4 / S5 ≤ 60%, 40% ≤ S4 / S5 ≤ 55%, etc. Specifically, S4 / S5 can be 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 75%, etc., including but not limited to the listed values, and other values ​​between any two of the above still apply. This configuration can increase the connection reliability between the first insulating member 121 and the metal layer 11. When S4 / S5 is less than 20%, the connection area between the first insulating element 121 and the metal layer 11 is too small, resulting in low connection reliability between the first insulating element 121 and the metal layer 11. When S4 / S5 > 75%, the connection area between the first insulating element 121 and the metal layer 11 is too large, which will result in an excessively large total opening area of ​​the first through hole 125 of the second insulating element 122, affecting the strength of the second insulating element 122.

[0083] In some embodiments, please refer to Figure 7 and Figure 8 The second insulating member 122 covers both ends of the first insulating member 121 along its length direction; and the second insulating member 122 also covers both sides of the first insulating member 121 along its width direction. It can be understood that the second insulating member 122 covers both ends of the first insulating member 121 along its length and width directions, thus embedding the first insulating member 121 within the second insulating member 122, forming an integral insulating layer 12. Simultaneously, since the second insulating member 122 has better heat dissipation than the first insulating member 121, this arrangement allows the second insulating member 122 to carry away the heat from the first insulating member 121, preventing the first insulating member 121 from deforming due to heat.

[0084] In some embodiments, please refer to Figure 8The second insulating member 122 includes a first body 120 and a boss 123. The boss 123 is located at both ends of the first body 120 along its length and protrudes from the first body 120 in a direction away from the metal layer 11. The boss 123 is used to abut against the electrode assembly 30 to prevent the electrode assembly 30 from shifting. Since the boss 123 directly abuts against the electrode assembly 30 and the second insulating member 122 has relatively good heat dissipation performance, the heat from the electrode assembly 30 and the first insulating member 121 can be quickly dissipated through the second insulating member 122, preventing the first insulating member 121 from deforming due to heat and improving the overall heat dissipation capacity of the top cover assembly.

[0085] In some other embodiments, please refer to Figure 1 and Figure 2 The first insulating member 121 at least covers both ends of the second insulating member 122 along its length. It is understood that the first insulating member 121 covers the second insulating member 122 at both ends along its length. With this arrangement, the second insulating member 122 is embedded within the first insulating member 121, forming an integral insulating layer 12 between them.

[0086] In some embodiments, such as Figure 2 As shown, the first insulating member 121 includes a second body 128 and a boss 123. The boss 123 is disposed at both ends of the second body 128 along its length direction and protrudes from the second body 128 in a direction away from the metal layer 11. The boss 123 is used to abut against the electrode assembly 30 to prevent the electrode assembly 30 from shifting.

[0087] Of course, in some other embodiments, the first insulating member 121 covers both sides of the second insulating member 122 along its width direction. It is understood that the first insulating member 121 may also cover the second insulating member 122 at both ends of the second insulating member 122 in the width direction. In this way, the second insulating member 122 is embedded in the first insulating member 121, and an integral insulating layer 12 is formed between the two.

[0088] As one embodiment of the top cover assembly, please refer to Figure 1 or Figure 7The top cover assembly also includes: a terminal post 13 and a third insulating member 14, wherein the third insulating member 14 and the first insulating member 121 are integrally formed. The terminal post 13 is fixed to the top cover plate 10. The terminal post 13 can be electrically connected to the electrode assembly 30 for outputting or inputting electrical energy of the battery cell. The terminal post 13 includes a positive terminal post and a negative terminal post. The positive terminal post is used to connect to the positive electrode tab, thereby introducing the positive current of the battery cell into the interior of the housing 40 or leading it out to the exterior of the housing 40. The negative terminal post is used to connect to the negative electrode tab, thereby introducing the negative current of the battery cell into the interior of the housing 40 or leading it out to the exterior of the housing 40. The positive and negative terminals of adjacent battery cells can be electrically connected in series, parallel, or mixed manner through electrical connectors. It should be noted that the "terminal post 13" mentioned in this application can be either a positive terminal post or a negative terminal post (unless otherwise explicitly stated). Simply ensure that the tab connected to the positive terminal is the positive terminal tab, and the tab connected to the negative terminal is the negative terminal tab.

[0089] Please refer to Figure 6 or Figure 10 The third insulating element 14 is fixed between the terminal post 13 and the metal layer 11 to insulate the terminal post 13 and the metal layer 11. The third insulating element 14 can be made of plastic materials, such as PP, PE, PPS, etc.

[0090] It is understood that the top cover plate 10 of this application can, together with the pole post 13, the third insulating member 14, and other functional components, form a top cover assembly. Other functional components may also be insulating structures such as lower plastic parts.

[0091] Please refer to Figure 6 or Figure 10 The third insulating member 14 includes a first insulating portion 141 and a second insulating portion 142, which are integrally formed. The first insulating portion 141, the second insulating portion 142, and the first insulating member 121 are located on the side of the metal layer 11 opposite to the insulating layer 12. In some embodiments, to fix the first insulating portion 141 and the metal layer 11, at least a portion of the first insulating portion 141 is projected onto the surface of the metal layer 11, so that the first insulating portion 141 and the first insulating member 121 engage and fix the metal layer 11 on both surfaces in the thickness direction of the metal layer 11. Please refer to... Figure 1 or Figure 7 The metal layer 11 has a second through hole 111 extending through its thickness direction, and the second insulating part 142 is disposed between the hole wall of the second through hole 111 and the electrode post 13. The side of the second insulating part 142 away from the first insulating part 141 is connected to the first insulating member 121 as a whole, thus eliminating the need for a sealing ring structure and improving the utilization rate of the internal space of the battery cell.

[0092] Please refer to Figure 1 , Figure 2 or Figure 7 , Figure 8 The second insulating member 122 is further provided with a third through hole 124 extending through its thickness direction. On a dummy plane perpendicular to the thickness direction of the top cover plate 10, the orthographic projection of the third through hole 124 overlaps the orthographic projection of the second through hole 111. In some embodiments, the central axis of the third through hole 124 coincides with the central axis of the second through hole 111. On a dummy plane perpendicular to the thickness direction of the top cover plate 10, the diameter of the second through hole 111 of the metal layer 11 is smaller than the diameter of the third through hole 124 of the second insulating member 122. Figure 6 or Figure 10 As shown, at least a portion of the first insulating member 121 passes through the third through hole 124 and connects to the metal layer 11. Simultaneously, the portion of the first insulating member 121 passing through the third through hole 124 is integrally formed with the second insulating portion 142. Thus, the pole post 13 can be inserted into the third through hole 124 and the second through hole 111, thereby fixing the second insulating member 122 and the pole post 13 and reducing the risk of the pole post 13 detaching.

[0093] Please refer to Figure 2 or Figure 8 In some embodiments, at least a portion of the first through hole 125 on the second insulating member 122 is arranged in an arc around the third through hole 124 and communicates with the third through hole 124. For example, as Figure 2 or Figure 8 As shown, two arc-shaped first through holes 125 are provided around the third through hole 124. The design of the arc-shaped first through holes 125 can increase the connection area of ​​the first insulating member 121, the second insulating member 122 and the metal layer 11, and improve the connection reliability between the metal layer 11, the second insulating member 122 and the first insulating member 121.

[0094] In some embodiments, please refer to Figure 1 , Figure 6 or Figure 7 , Figure 10 The electrode post 13 includes a first connecting portion 131 and a second connecting portion 132. The first connecting portion 131 passes through the second through hole 111 and the third through hole 124 and is connected to an electrical connector. The second connecting portion 132 is disposed on the side surface of the insulating layer 12 facing away from the metal layer 11 and is used to connect to the tab of the electrode assembly 30. In some embodiments, on a dummy plane perpendicular to the thickness direction of the top cover plate 10, the orthographic projection of the second connecting portion 132 is larger than the orthographic projection of the first connecting portion 131, and at least a portion of the orthographic projection of the second connecting portion 132 falls on the surface of the insulating layer 12, so that the second connecting portion 132 can be engaged on the surface of the insulating layer 12 facing away from the metal layer 11.

[0095] As another embodiment of the top cover assembly, please refer to Figures 11 to 13 The top cover assembly also includes: a pole post 13, a third insulating member 14, and a sealing member 16. The pole post 13 is fixed to the top cover plate 10; the third insulating member 14 is fixed between the pole post 13 and the metal layer 11; and the sealing member 16 is disposed between the metal layer 11 and the pole post 13. It is understood that the top cover plate 10 of this application can, together with the pole post 13, the third insulating member 14, the sealing member 16, and other functional components, form a top cover assembly. Other functional components may also be insulating structures such as a lower plastic part.

[0096] The terminal 13 can be electrically connected to the electrode assembly 30 for outputting or inputting electrical energy from the battery cell. The terminal 13 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 40 or leading it out to the exterior of the housing 40. 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 40 or leading it out to the exterior of the housing 40. The positive and negative terminals of adjacent battery cells can be electrically connected in series, parallel, or mixed configurations using electrical connectors. It should be noted that the "terminal 13" mentioned in this application can be either a positive terminal or a negative terminal (unless explicitly stated otherwise). It is sufficient that the terminal connected to the positive terminal is the positive electrode tab, and the terminal connected to the negative terminal is the negative electrode tab.

[0097] Please refer to Figure 13 The third insulating member 14 is fixed between the pole post 13 and the metal layer 11. The third insulating member 14 and the first insulating member 121 are separate structures. The third insulating member 14 is fixed between the pole post 13 and the metal layer 11 to insulate the pole post 13 and the metal layer 11. The third insulating member 14 can be made of plastic materials, such as PP, PE, or PPS. The third insulating member 14 includes a first insulating portion 141 and a second insulating portion 142. The first insulating portion 141 is located on the side of the metal layer 11 opposite to the insulating layer 12. In some embodiments, to fix the first insulating portion 141 to the metal layer 11, at least a portion of the first insulating portion 141 is projected onto the surface of the metal layer 11 so that the first insulating portion 141 can engage with the surface of the metal layer 11. The metal layer 11 has a second through hole 111 extending through its thickness direction. A second insulating part 142 is disposed between the wall of the second through hole 111 and the electrode post 13. The second insulating part 142, the electrode post 13, and the insulating layer 12 together form a receiving cavity, and a sealing member 16 is disposed in the receiving cavity. The sealing member 16 is then used to seal the second through hole 111 to prevent electrolyte leakage.

[0098] In some embodiments, to further secure the third insulating member 14 and the pole post 13, please refer to... Figure 13 and Figure 16The electrode post 13 includes a first connecting portion 131 and a second connecting portion 132. The first connecting portion 131 passes through the second through hole 111 and the third through hole 124 and is connected to the electrical connector. The second connecting portion 132 is disposed on the side surface of the insulating layer 12 facing away from the metal layer 11 and is used to connect to the electrode tab of the electrode assembly 30. In some embodiments, on a dummy plane perpendicular to the thickness direction of the top cover plate 10, the orthographic projection of the second connecting portion 132 is larger than the orthographic projection of the first connecting portion 131, and the orthographic projection of the second connecting portion 132 falls on the surface of the insulating layer 12, so that the second connecting portion 132 can be engaged on the surface of the insulating layer 12 facing away from the metal layer 11. A third groove 133 is provided circumferentially in the first connecting portion 131, and at least a portion of the second insulating portion 142 of the third insulating member 14 is engaged in the third groove 133, thereby fixing the third insulating member 14 and the electrode post 13 and preventing the electrode post 13 from falling off.

[0099] To further secure the metal layer 11 and the third insulating element 14, please refer to... Figure 14 A first groove 110 is provided on the surface of the metal layer 11 facing away from the insulating layer 12 and surrounding the second through hole 111. A portion of the first insulating part 141 is accommodated within the first groove 110, and the edge of the first insulating part 141 away from the center of the second through hole 111 covers the surface of the metal layer 11. This allows for the snap-fit ​​between the third insulating member 14 and the metal layer 11. To further achieve the snap-fit ​​between the third insulating member 14 and the metal layer 11, such as... Figure 14 As shown, a plurality of second grooves 114 are provided on the side surface of the metal layer 11 facing away from the insulating layer 12 and surrounding the groove sidewall of the first groove 110. The second grooves 114 are connected to the first grooves 110 and extend in a direction away from the central axis of the second through hole 111, as shown. Figure 4 or Figure 15 As shown, a snap-fit ​​portion 144 is provided on the first insulating portion 141 of the third insulating member 14. The snap-fit ​​portion 144 of the first insulating portion 141 is snapped into the second groove 114, thereby further realizing the snap-fit ​​fixation of the third insulating member 14 and the metal layer 11.

[0100] In some embodiments, please refer to Figure 1 , Figure 2 , Figure 3 or Figure 7 , Figure 8 or Figure 14 The metal layer 11 is provided with a first liquid injection hole 112, and the second insulating member 122 is provided with a second liquid injection hole 126 corresponding to the first liquid injection hole 112; so that electrolyte can be injected into the battery cell through the first liquid injection hole 112 and the second liquid injection hole 126.

[0101] In some embodiments, please refer to Figure 1 , Figure 2 , Figure 3 or Figure 7 , Figure 8 or Figure 14 The metal layer 11 is provided with a pressure relief mechanism 113, and the second insulating member 122 is provided with an exhaust port 127 corresponding to the pressure relief mechanism 113. When the internal gas pressure of the battery cell increases, the exhaust port 127 is used to allow the gas inside the battery cell to be discharged through the exhaust port 127 and from the pressure relief mechanism 113, so as to avoid thermal runaway.

[0102] In some embodiments, please refer to Figure 1 or Figure 7 or Figure 11 A protective film 15 is provided on the surface of the metal layer 11 away from the insulating layer 12 to protect and insulate the metal layer 11.

[0103] This application also provides a method for processing a top cover assembly, comprising the following steps: The second insulating member 122 and the metal layer 11 are positioned such that the central axis of the third through hole 124 of the second insulating member 122 is aligned with the central axis of the second through hole 111 of the metal layer 11. That is, the second insulating member 122 and the metal layer 11 are stacked such that the central axis of the third through hole 124 of the second insulating member 122 is aligned with the central axis of the second through hole 111 of the metal layer 11.

[0104] The first insulating member 121 is injection molded onto the surface of the metal layer 11, and at least a portion of the first insulating member 121 is embedded in the first through hole 125 of the second insulating member 122 and connected to the metal layer 11. This forms a reliable connection between the first insulating member 121, the second insulating member 122, and the metal layer 11, making the first insulating member 121, the second insulating member 122, and the metal layer 11 a single integral structure.

[0105] In some embodiments, the first insulating member 121 is injection molded using a nano-injection molding method. Therefore, a first nanopore is pre-formed on the surface of the metal layer 11 in contact with the first insulating member 121, and at least a portion of the first insulating member 121 is embedded in the first nanopore and connected to the metal layer 11 during injection molding; a second nanopore is pre-formed on the surface of the second insulating member 122 in contact with the first insulating member 121, and at least a portion of the first insulating member 121 is embedded in the second nanopore and connected to the second insulating member 122 during injection molding. During the manufacturing process, the surface treatment of the metal layer 11 and the second insulating member 122 can be chemically etched to form a nanopore structure, thereby increasing the connection surface area between the first insulating member 121 and the metal layer 11 and the second insulating member 122, and improving the bonding force between the first insulating member 121 and the metal layer 11 and the second insulating member 122.

[0106] 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) includes a metal layer (11) and an insulating layer (12) along its thickness direction. The insulating layer (12) includes a first insulating element (121) and a second insulating element (122), wherein the mechanical strength of the second insulating element (122) is greater than that of the first insulating element (121). The second insulating element (122) is provided with at least one first through hole (125) extending through its thickness direction, and at least a portion of the first insulating element (121) is accommodated in the first through hole (125).

2. The top cover assembly according to claim 1, characterized in that, The first insulating element (121) is connected to the metal layer (11) on the side facing the metal layer (11).

3. The top cover assembly according to claim 2, characterized in that, The surface of the first insulating member (121) facing the metal layer (11) is flush with the surface of the second insulating member (122) facing the metal layer (11), and the surface of the first insulating member (121) away from the metal layer (11) is flush with the surface of the second insulating member (122) away from the metal layer (11).

4. The top cover assembly according to claim 3, characterized in that, On a virtual plane perpendicular to the thickness direction of the insulating layer (12), the projected area of ​​the solid portion of the second insulating member (122) is greater than the projected area of ​​the solid portion of the first insulating member (121).

5. The top cover assembly according to claim 4, characterized in that, The second insulating member (122) covers both ends of the first insulating member (121) along its length direction; and the second insulating member (122) covers both sides of the first insulating member (121) along its width direction.

6. The top cover assembly according to claim 5, characterized in that, The second insulating member (122) includes a first body (120) and a boss (123). The boss (123) is located at both ends of the first body (120) along its length direction and protrudes from the first body (120) in a direction away from the metal layer (11).

7. The top cover assembly according to claim 4, characterized in that, The first insulating element (121) covers at least both ends of the second insulating element (122) along its length.

8. The top cover assembly according to claim 7, characterized in that, The first insulating member (121) includes a second body (128) and a boss (123). The boss (123) is located at both ends of the second body (128) along its length direction and protrudes from the second body (128) in a direction away from the metal layer (11).

9. The top cover assembly according to claim 7, characterized in that, The first insulating element (121) covers both sides of the second insulating element (122) along its width direction.

10. The top cover assembly according to claim 3, characterized in that, Also includes: The pole post (13) is fixed to the top cover plate (10); The third insulating element (14) is fixed between the pole post (13) and the metal layer (11), wherein the third insulating element (14) and the first insulating element (121) are integrally formed.

11. The top cover assembly according to claim 10, characterized in that, The third insulating element (14) includes a first insulating part (141) and a second insulating part (142), wherein the first insulating part (141) is disposed on the side of the metal layer (11) away from the insulating layer (12), the metal layer (11) is provided with a second through hole (111) penetrating its thickness direction, and the second insulating part (142) is disposed between the hole wall of the second through hole (111) and the pole post (13), wherein the first insulating part (141), the second insulating part (142) and the first insulating element (121) are integrally formed.

12. The top cover assembly according to claim 11, characterized in that, The second insulating member (122) is also provided with a third through hole (124) extending through its thickness direction. On a dummy plane perpendicular to the thickness direction of the top cover plate (10), the orthographic projection of the third through hole (124) covers the orthographic projection of the second through hole (111). At least a portion of the first insulating member (121) is disposed in the third through hole (124) around the hole wall of the third through hole (124) and connected to the metal layer (11).

13. The top cover assembly according to claim 12, characterized in that, On the second insulating member (122), at least a portion of the first through hole (125) is arranged in an arc around the third through hole (124) and communicates with the third through hole (124).

14. The top cover assembly according to claim 3, characterized in that, Also includes: The pole post (13) is fixed to the top cover plate (10); The third insulating element (14) is fixed between the pole post (13) and the metal layer (11); A seal (16) is disposed between the metal layer (11) and the pole (13).

15. The top cover assembly according to claim 14, characterized in that, The third insulating element (14) includes a first insulating part (141) and a second insulating part (142). The first insulating part (141) is disposed on the side of the metal layer (11) away from the insulating layer (12). The metal layer (11) has a second through hole (111) penetrating its thickness direction. The second insulating part (142) is disposed between the hole wall of the second through hole (111) and the pole post (13). The second insulating part (142), the pole post (13) and the first insulating element (121) surround and form a receiving cavity. The sealing element (16) is disposed in the receiving cavity.

16. The top cover assembly according to any one of claims 1 to 15, characterized in that, The metal layer (11), the first insulating element (121) and the second insulating element (122) are an integral structure.

17. The top cover assembly according to claim 16, characterized in that, The metal layer (11) has a first nanopore on the surface in contact with the first insulating member (121), and at least a portion of the first insulating member (121) is embedded in the first nanopore and connected to the metal layer (11); and / or, The second insulating member (122) has a second nanopore on the surface that contacts the first insulating member (121), and at least a portion of the first insulating member (121) is embedded in the second nanopore and connected to the second insulating member (122).

18. The top cover assembly according to claim 16, characterized in that, The connection area between the first insulating element (121) and the metal layer (11) is S4, satisfying: 300mm² 2 ≤S4≤15000mm 2 ; and / or, On a virtual plane perpendicular to the thickness direction of the top cover plate (10), the area of ​​the orthographic projection region of the outer contour of the metal layer (11) is S5, satisfying: 1300mm². 2 ≤S5≤20000mm 2 ; and / or, Satisfying: 20% ≤ S4 / S5 ≤ 75%; and / or, Along the thickness direction of the top cover plate (10), the thickness of the metal layer (11) is a, satisfying: 0.1mm ≤ a ≤ 1.5mm; and / or, Along the thickness direction of the top cover plate (10), the thickness of the metal layer (11) is a, and the total thickness of the top cover plate (10) is b, satisfying: 5%≤a / b≤60%.

19. The top cover assembly according to any one of claims 1 to 15, characterized in that, The first through hole (125) is elongated and / or arc-shaped; and / or, The first through hole (125) is arranged on the second insulating member (122) along its length and / or along its width; and / or, The total area of ​​the first through hole (125) is S1, and the area of ​​the orthographic projection region of the outer contour of the second insulating member (122) on a fictitious plane perpendicular to the thickness direction of the top cover plate (10) is S2, satisfying: 10%≤S1 / S2≤70%; and / or, The metal layer (11) is provided with a first liquid injection hole (112), and the second insulating member (122) is provided with a second liquid injection hole (126) corresponding to the first liquid injection hole (112); and / or, The metal layer (11) is provided with a pressure relief mechanism (113), and the second insulating member (122) is provided with an exhaust hole (127) corresponding to the pressure relief mechanism (113).

20. A single battery cell, characterized in that, Includes the top cover assembly as described in any one of claims 1 to 19.

21. A battery, characterized in that, Includes the battery cell as described in claim 20.

22. An electrical appliance, characterized in that, Includes the battery cell of claim 20, or the battery of claim 21.

23. A method for processing a top cover assembly, characterized in that, Includes the following steps: Position the second insulating element (122) and the metal layer (11) so that the central axis of the third through hole (124) of the second insulating element (122) is aligned with the central axis of the second through hole (111) of the metal layer (11); The first insulating element (121) is injection molded onto the surface of the metal layer (11), and at least a portion of the first insulating element (121) is embedded in the first through hole (125) of the second insulating element (122) and connected to the metal layer (11).

24. The processing method according to claim 23, characterized in that, Also includes: A first nanopore is pre-formed on the surface of the metal layer (11) that contacts the first insulating member (121), and at least a portion of the first insulating member (121) is embedded in the first nanopore and connected to the metal layer (11) during injection molding; and / or, A second nanopore is pre-formed on the surface of the second insulating member (122) that contacts the first insulating member (121), and at least a portion of the first insulating member (121) is embedded in the second nanopore and connected to the second insulating member (122) during injection molding.

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