A top cover assembly, a battery monomer and an electric device

Abstract

The application relates to a top cover assembly, a battery monomer and an electric device. The top cover assembly comprises a top cover with a first surface, a second surface and a first through hole, the first surface and the second surface are opposite to each other, and the first through hole penetrates the first surface and the second surface; a pole column comprising a first connecting part and a second connecting part connected with the first connecting part, the first connecting part is located on one side of the top cover with the first surface and is used for electrically connecting with a bus bar, the second connecting part is arranged in the first through hole and is used for electrically connecting with a tab; and an insulation assembly located between the top cover and the first connecting part and comprising an insulation layer and an adhesive layer; the insulation layer is connected on one of the top cover and the first connecting part, the adhesive layer is connected on the other one of the top cover and the first connecting part, and the insulation layer and the adhesive layer are connected with each other through adhesion.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a top cover assembly, a battery cell, and an electrical device. Background Technology

[0002] Lithium-ion batteries have advantages such as high energy density, long cycle life, high rate performance, good safety, and environmental friendliness, making them an important energy source for modern electronic products and electric vehicles. The battery cell is a crucial component of the battery.

[0003] In existing technology, the top cover of a battery cell has terminal holes, with the terminals located on the outside of the top cover and partially extending through the terminal holes to the inside of the top cover for electrical connection with the cell's tabs. To achieve insulation between the terminals and the cover, a PPS insulation layer needs to be injection-molded between them. However, when the terminals or cover are deformed under external pressure, the PPS insulation layer is prone to cracking, leading to insulation failure. Utility Model Content

[0004] Therefore, it is necessary to provide a top cover assembly, battery cell, and electrical device that can improve insulation performance in response to the above problems.

[0005] On one hand, this application provides a top cover assembly, including:

[0006] The top cover has a first surface, a second surface, and a first through hole, wherein the first surface and the second surface are opposite to each other, and the first through hole penetrates the first surface and the second surface;

[0007] The electrode post includes a first connecting portion and a second connecting portion connected to the first connecting portion. The first connecting portion is located on the side of the top cover having the first surface and is used for electrical connection to a busbar. The second connecting portion passes through the first through hole and is used for electrical connection to a tab.

[0008] An insulating component is located between the top cover and the first connecting portion, and includes an insulating layer and an adhesive layer; the insulating layer is connected to one of the top cover and the first connecting portion, the adhesive layer is connected to the other of the top cover and the first connecting portion, and the insulating layer and the adhesive layer are bonded to each other.

[0009] In some embodiments, the first connecting portion has a first annular baffle protruding from the side facing the top cover, and the first annular baffle forms a first groove.

[0010] The insulating layer fills the first groove, and a portion of the insulating layer protrudes from the first annular baffle in the direction toward the top cover.

[0011] In some embodiments, the adhesive layer is applied to the side of the top cover having the first surface and is located between the insulating layer and the first annular baffle and the top cover.

[0012] In some embodiments, the top cover has a second annular baffle protruding from the side facing the first connection portion, and the second annular baffle forms a second groove.

[0013] The insulating layer fills the second groove, and a portion of the insulating layer protrudes from the second annular retainer in the direction toward the first connection portion.

[0014] In some embodiments, the first surface of the top cover is recessed to form an assembly groove, the first through hole is opened in the assembly groove, the first connecting portion is located in the assembly groove, the second annular baffle protrudes from the bottom wall of the assembly groove, and the height of the second annular baffle relative to the bottom wall of the assembly groove is less than or equal to the depth of the assembly groove.

[0015] In some embodiments, the first connecting portion has an annular groove on the side facing the top cover, and the second annular baffle is opposite to the annular groove in the thickness direction of the top cover.

[0016] On the other hand, this application provides a top cover assembly, including:

[0017] The top cover has a first surface, a second surface, and a first through hole, wherein the first surface and the second surface are opposite to each other, and the first through hole penetrates the first surface and the second surface;

[0018] The electrode post includes a first connecting portion and a second connecting portion connected to the first connecting portion. The first connecting portion is located on the side of the top cover having the first surface and is used for electrical connection to a busbar. The second connecting portion passes through the first through hole and is used for electrical connection to a tab.

[0019] An insulating component, located between the top cover and the first connecting portion, includes a first polymer layer and a second polymer layer; the first polymer layer is connected to the side of the top cover facing the first connecting portion, and the second polymer layer is connected to the side of the first connecting portion facing the top cover, and the first polymer layer and the second polymer layer are connected by chemical bonds.

[0020] In some embodiments, the first connecting portion has a first annular baffle protruding from the side facing the top cover, the first annular baffle forming a first groove; the second polymer layer fills the first groove, and a portion of the second polymer layer protrudes from the first annular baffle in the direction facing the top cover; or

[0021] The top cover has a second annular baffle protruding from the side facing the first connection portion, and the second annular baffle forms a second groove; the first polymer layer fills the second groove, and a portion of the first polymer layer protrudes from the second annular baffle in the direction facing the first connection portion.

[0022] In another aspect, this application provides a battery cell including the top cover assembly as described in any of the above embodiments.

[0023] In another aspect, this application provides an electrical device including a battery cell as described in any of the above embodiments.

[0024] Compared with the prior art, this application has the following beneficial effects:

[0025] The aforementioned top cover assembly, battery cell, and electrical device have an insulating layer formed on one of the top cover and the first connecting part, and then the insulating layer is bonded and fixed to the other of the top cover and the first connecting part using an adhesive layer. This greatly improves the connection strength between the first connecting part, the insulating layer, the adhesive layer, and the top cover, and can effectively resist the deformation force generated by the deformation of the pole or the top cover, avoid cracking, and thus provide reliable insulation performance. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of a single battery cell in one embodiment of this application;

[0027] Figure 2 for Figure 1 A schematic diagram of the top cover assembly of the battery cell shown;

[0028] Figure 3 for Figure 2 A top view of the top cover assembly shown;

[0029] Figure 4 for Figure 3 The top cover assembly shown is a cross-sectional view along the AA direction;

[0030] Figure 5 This is a cross-sectional view of the top cover assembly in another embodiment of this application;

[0031] Figure 6 This is a cross-sectional view of the top cover assembly in another embodiment of this application;

[0032] Figure 7 This is a cross-sectional view of the top cover assembly in another embodiment of this application. Detailed Implementation

[0033] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0034] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0035] 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 at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0036] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0037] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0038] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0039] One embodiment of this application provides an electrical device, a battery, a battery cell, and a top cover assembly. The electrical device includes a battery or a battery cell and is capable of providing electrical energy from the battery or battery cell. The electrical device can be a vehicle, mobile phone, portable device, laptop computer, ship, spacecraft, electric toy, power tool, energy storage device, amusement equipment, elevator, and lifting equipment, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, or electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.; energy storage devices can be energy storage walls, base station energy storage, container energy storage, etc.; amusement equipment can be a carousel, a drop tower, etc.

[0040] 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 vehicles, etc. For new energy vehicles, the aforementioned battery can serve as a driving power source, thereby replacing fossil fuels to provide propulsion. This application does not impose any special restrictions on the aforementioned electrical devices.

[0041] 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.

[0042] 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 busbars. Alternatively, 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 busbar can be the terminal of another battery cell. Similarly, battery cells and the battery management system can also be electrically connected via mutual insertion, which will not be elaborated further here. The aforementioned battery cells can be lithium-ion, sodium-ion, or magnesium-ion batteries, and their external contours can be cylindrical, flat, cuboid, or other shapes, but are not limited to these. Specifically, in this embodiment, the aforementioned battery cell is a lithium-ion square battery.

[0043] Please see Figure 1 The aforementioned battery cell includes a top cover assembly 100, a housing 200, and a cell assembly (not shown). The housing 200 has an opening at at least one end and a receiving cavity communicating with the opening. The cell assembly is housed within the receiving cavity of the housing 200, and the top cover assembly 100 covers the opening of the housing 200, thereby enclosing the cell assembly within the receiving cavity of the housing 200. The cell assembly may be a single-core battery with two sets of tabs of the same polarity arranged along the thickness direction of the core. Alternatively, the cell assembly may include at least two sets of cells arranged side-by-side along the thickness direction of the housing 200, each set of cells extending tabs toward the end face of the top cover assembly 100.

[0044] It should be noted that each group of cells can be a single cell or multiple cells, and this is not limited here. When each group of cells includes a single cell, the cell extends a positive tab and a negative tab towards the end face of the top cover assembly 100. When each group of cells includes multiple cells, each cell extends a positive tab and a negative tab towards the end face of the top cover assembly 100. The positive tabs on the cells in the same group are brought together to form a single positive tab, and the negative tabs on the cells in the same group are brought together to form a single negative tab.

[0045] In one embodiment, the battery cell assembly includes two sets of battery cells, each set of battery cells including one battery cell. That is, the battery cell assembly includes a total of two battery cells. The two battery cells are arranged side by side along the thickness direction of the housing 200. One of the battery cells has a positive tab and a negative tab on the end face facing the top cover assembly 100. The other battery cell also has a positive tab and a negative tab on the end face facing the top cover assembly 100.

[0046] Please see Figures 2 to 4In an embodiment of this application, the top cover assembly 100 includes a top cover 10, a terminal post 20, and an insulating assembly 30. The top cover 10 has a first surface a1, a second surface a2, and a first through hole 11. The first surface a1 and the second surface a2 are opposite to each other in the thickness direction of the top cover 10, and the first through hole 11 penetrates the first surface a1 and the second surface a2 of the top cover 10. The top cover 10 is disposed on the opening of the housing 200 to seal the opening of the housing 200. The first surface a1 of the top cover 10 faces away from the cell assembly inside the housing 200's receiving cavity, and the second surface a2 of the top cover 10 faces the cell assembly inside the housing 200's receiving cavity.

[0047] The terminal post 20 is disposed on the top cover 10, which can be equipped with a positive terminal post and a negative terminal post. The positive terminal post is used to connect to the positive tab of each group of battery cells, thereby leading the positive tab of each group of battery cells out of the housing 200. The negative terminal post is used to connect to the negative tab of each group of battery cells, thereby leading the negative tab of each group of battery cells out of the housing 200. The positive terminal post serves as the positive terminal of the battery cell, and the negative terminal post serves as the negative terminal of the battery cell. The positive and negative terminals of each battery cell are connected by a busbar to achieve series, parallel, or mixed series and parallel electrical connection of the battery cells.

[0048] It should be noted that, due to the similarity in structure between the positive and negative terminals, this article will use one of the terminals, 20, as an example for ease of understanding. That is to say, "terminal 20" in this article can be either a positive or negative terminal (unless explicitly stated otherwise), and "tab" in this article can be either a positive or negative tab (unless explicitly stated otherwise), as long as all tabs connected to the positive terminal are positive tabs and all tabs connected to the negative terminal are negative tabs.

[0049] The electrode post 20 includes a first connecting portion 21 and a second connecting portion 22 connected to the first connecting portion 21. The first connecting portion 21 is located on the side of the top cover 10 having a first surface a1 and is used for electrical connection to the busbar. The second connecting portion 22 passes through the first through hole 11 and is used for electrical connection to the corresponding electrode tab. For example, one end of the second connecting portion 22 passing through the first through hole 11 is welded to the electrode tab.

[0050] The insulating component 30 is located between the top cover 10 and the first connecting portion 21, serving to form insulation between the first connecting portion 21 and the top cover 10, and also providing support for the first connecting portion 21 of the pole post 20. The insulating component 30 includes an insulating layer 31 and an adhesive layer 32. The insulating layer 31 is connected to the surface of the first connecting portion 21 facing the top cover 10, and the adhesive layer 32 is connected to the surface of the top cover 10 facing the first connecting portion 21, and the insulating layer 31 and the adhesive layer 32 are bonded together. Of course, in other embodiments, the insulating layer 31 may also be connected to the surface of the top cover 10 facing the first connecting portion 21, and the adhesive layer 32 may be connected to the surface of the first connecting portion 21 facing the top cover 10.

[0051] Compared with the prior art where a PPS insulating layer is injection molded between the pole post 20 and the top cover 10, in this application, the insulating layer 31 is molded on one of the top cover 10 and the first connecting part 21, and then the insulating layer 31 is bonded and fixed to the other of the top cover 10 and the first connecting part 21 using the adhesive layer 32. This greatly improves the connection strength between the first connecting part 21, the insulating layer 31, the adhesive layer 32 and the top cover 10, and can effectively resist the deformation force generated by the deformation of the pole post 20 or the top cover 10, avoid cracking, and thus provide reliable insulation performance.

[0052] Please see Figure 4 In some embodiments, the first connecting portion 21 has a first annular baffle 211 protruding from the side facing the top cover 10, which encloses to form a first groove 213. The insulating layer 31 fills the first groove 213 on the first connecting portion 21, and a portion of the insulating layer 31 protrudes from the first annular baffle 211 in the direction facing the top cover 10, so as to make full contact with the adhesive layer 32 located between the insulating layer 31 and the top cover 10 and bond them together.

[0053] The adhesive layer 32 is coated on the side of the top cover 10 having the first surface a1 and is located between the insulating layer 31 and the first annular baffle 211 and the top cover 10, thereby maximizing the contact area between the insulating layer 31 and the adhesive layer 32 and further enhancing the bonding strength between them.

[0054] During assembly, liquid insulating material is first injected into the first groove 213 of the first connecting part 21, and the liquid insulating material in the first groove 213 of the first connecting part 21 is vulcanized and cured to form an insulating layer 31, which is then bonded to the surface of the first connecting part 21 and cannot be separated. Then, adhesive is applied to the top cover 10, and the pole 20 is assembled to the top cover 10, so that the insulating layer 31 on the first connecting part 21 and the adhesive form an adsorption and mechanical interlock. The insulating layer 31 and the adhesive can form adhesion, penetration, and co-crosslinking through diffusion, and after the adhesive cures, an adhesive layer 32 is formed. This greatly improves the connection strength between the first connecting part 21, the insulating layer 31, the adhesive layer 32, and the top cover 10, effectively resisting the deformation force generated by the deformation of the pole 20 or the top cover 10, avoiding cracking, and thus providing reliable insulation performance.

[0055] Optionally, the height of the insulating layer 31 protruding from the first annular baffle 211 in the direction toward the top cover 10 is 0.1 mm to 0.3 mm, for example, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm or 0.3 mm.

[0056] The depth of the first groove 213 is 0.6 mm to 1.2 mm, preferably 0.8 mm to 1.0 mm. For example, the depth of the first groove 213 is 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm or 1.2 mm, etc.

[0057] There is a first gap between the first annular baffle 211 and the top cover 10, and the width of the first gap is greater than or equal to 0.02 mm, so as to ensure that the creepage distance between the first annular baffle 211 and the top cover 10 is large enough to meet the insulation requirements.

[0058] The insulation layer 31 has a thickness of 0.7 mm to 1.5 mm, and the adhesive layer 32 has a thickness of 0.2 mm to 0.4 mm. The insulation layer 31 and the adhesive layer 32 overlap by at least 0.1 mm in the thickness direction to ensure that the bonding strength between the insulation layer 31 and the adhesive layer 32 meets the requirements.

[0059] Optionally, the insulating layer 31 can be silicone sealant, polyurethane sealant, acrylic sealant, or polysulfide sealant, etc. The adhesive layer 32 can be silicone adhesive, polyurethane adhesive, acrylic adhesive, or polysulfide adhesive, etc. It is understood that the principle of similarity compatibility refers to the fact that the more similar the molecular structure or polarity of two substances, the stronger the interaction between them, thus making it easier to form a stable mixture system. Based on the principle of similarity compatibility, the insulating layer 31 and the adhesive layer 32 need to be selected from materials with the same or similar chemical structures. For example, the insulating layer 31 can be silicone sealant, and the adhesive layer 32 can be silicone adhesive; or the insulating layer 31 can be polyurethane sealant, and the adhesive layer 32 can be polyurethane adhesive.

[0060] It should be noted that the insulating layer 31 is not limited to being disposed on the first connecting portion 21 of the pole post 20; in other embodiments, the insulating layer 31 may also be disposed on the top cover 10. Please refer to [link to relevant documentation]. Figure 5 As shown, specifically, a second annular baffle 13 protrudes from the side of the top cover 10 facing the first connecting portion 21, and the second annular baffle 13 encloses and forms a second groove 15. An insulating layer 31 fills the second groove 15 of the top cover 10, and a portion of the insulating layer 31 protrudes from the second annular baffle 13 in the direction facing the first connecting portion 21. An adhesive layer 32 is applied to the side of the first connecting portion 21 facing the top cover 10 and is bonded and fixed to the insulating layer 31. Thus, the insulating layer 31 is configured to partially protrude from the second annular baffle 13 in the direction facing the first connecting portion 21, so as to facilitate sufficient contact and bonding with the adhesive layer 32 located between the insulating layer 31 and the first connecting portion 21, ensuring that the bonding strength between the insulating layer 31 and the adhesive layer 32 meets the requirements.

[0061] During assembly, liquid insulating material is first injected into the second groove 15 of the top cover 10, and the liquid insulating material in the second groove 15 of the top cover 10 is vulcanized and cured to form an insulating layer 31, which is then bonded to the surface of the top cover 10 and cannot be separated. Next, adhesive is applied to the first connecting part 21, and the pole 20 is assembled to the top cover 10, so that the insulating layer 31 on the top cover 10 and the adhesive form an adsorption and mechanical interlock. The insulating layer 31 and the adhesive can form adhesion, penetration, and co-crosslinking through diffusion, and after the adhesive cures, an adhesive layer 32 is formed. This greatly improves the connection strength between the first connecting part 21, the adhesive layer 32, the insulating layer 31, and the top cover 10, effectively resisting the deformation force generated by the deformation of the pole 20 or the top cover 10, preventing cracking, and thus providing reliable insulation performance.

[0062] In a specific embodiment, the first surface a1 of the top cover 10 is recessed to form an assembly groove, and the first through hole 11 on the top cover 10 is opened in the assembly groove. The first connecting part 21 of the pole post 20 is located in the assembly groove. The second annular baffle 13 protrudes from the bottom wall of the assembly groove, and the height dimension of the second annular baffle 13 relative to the bottom wall of the assembly groove is smaller than the depth dimension of the assembly groove.

[0063] Optionally, the height of the second annular retaining strip 13 relative to the bottom wall of the mounting groove is 0.2 mm to 0.4 mm, for example, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, or 0.4 mm. The depth of the mounting groove is greater than or equal to 0.4 mm.

[0064] The gap between the bottom wall of the second groove 15 and the first connecting part 21 is approximately 0.8 mm. The thickness of the insulating layer 31 is 0.4 mm to 0.6 mm, and the thickness of the adhesive layer 32 is 0.3 mm to 0.6 mm.

[0065] In a specific embodiment, the first connecting portion 21 has an annular groove 215 on the side facing the top cover 10, and the second annular baffle 13 is opposite to the annular groove 215 in the thickness direction of the top cover 10. In this way, the annular groove 215 avoids the second annular baffle 13, ensuring that the creepage distance between the second annular baffle 13 and the first connecting portion 21 is large enough to meet the insulation requirements.

[0066] It should be noted that the insulating component 30 is not limited to a structure in which the insulating layer 31 and the adhesive layer 32 are bonded together. In other embodiments, the insulating component 30 may also employ a structure in which the first polymer layer and the second polymer layer are connected by chemical bonds. Please refer to [link to relevant documentation]. Figure 6 Specifically, the insulating component 30 includes a first polymer layer 35 and a second polymer layer 36. The first polymer layer 35 is connected to the side of the top cover 10 facing the first connection portion 21, and the second polymer layer 36 is connected to the side of the first connection portion 21 facing the top cover 10. The first polymer layer 35 and the second polymer layer 36 are connected by chemical bonds.

[0067] Compared with the prior art, which injection molds a PPS insulating layer between the pole post 20 and the top cover 10, this application molds a first polymer layer 35 and a second polymer layer 36 on the sides of the top cover 10 and the first connecting part 21 facing each other, respectively. The first polymer layer 35 and the second polymer layer 36 diffuse into each other and form stable chemical bonds between the terminal reactive groups, which greatly improves the connection strength between the top cover 10, the first polymer layer 35, the second polymer layer 36 and the first connecting part 21. This can effectively resist the deformation force generated by the deformation of the pole post 20 or the top cover 10, avoid cracking, and thus provide reliable insulation performance.

[0068] During assembly, a first polymer layer 35 is first formed on the surface of the top cover 10 facing the first connecting portion 21, thus modifying the surface of the top cover 10 facing the first connecting portion 21 using the first polymer layer 35. A second polymer layer 36 is then formed on the surface of the first connecting portion 21 facing the top cover 10, further modifying the surface of the first connecting portion 21 facing the top cover 10 using the second polymer layer 36. The pole post 20 is then assembled with the top cover 10, pressing the first polymer layer 35 and the second polymer layer 36 tightly together. Next, environmental stimuli (e.g., heating, specific light irradiation, specific pH value, electromagnetic field, and / or chemical reagents) are applied to the interface between the first polymer layer 35 and the second polymer layer 36, intensifying diffusion between them and forming stable chemical bonds between the terminal reactive groups.

[0069] It should be noted that the materials of the first polymer layer 35 and the second polymer layer 36 can be the same or different, and no special limitation is made here. Optionally, the first polymer layer 35 and the second polymer layer 36 can be one or more of the following: polydimethylsiloxane, polymethyl methacrylate, polystyrene, high-density polyethylene, polyvinyl polyurethane, carbon nanotube-polyurethane nanocomposite materials.

[0070] In some embodiments, a first annular baffle 211 protrudes from the side of the first connecting portion 21 facing the top cover 10, and the first annular baffle 211 encloses and forms a first groove 213. A second polymer layer 36 fills the first groove 213 of the first connecting portion 21, and a portion of the second polymer layer 36 protrudes from the first annular baffle 211 in the direction toward the top cover 10. A first polymer layer 35 is connected to the side of the top cover 10 facing the first connecting portion 21 and is chemically bonded to the second polymer layer 36. Thus, the second polymer layer 36 is configured to partially protrude from the first annular baffle 211 in the direction toward the top cover 10, so as to make sufficient contact with the first polymer layer 35 located between the second polymer layer 36 and the top cover 10 and form chemical bonds, ensuring that the chemical bond strength between the first polymer layer 35 and the second polymer layer 36 meets the requirements.

[0071] Optionally, the height of the second polymer layer 36 protruding from the first annular baffle 211 in the direction toward the top cover 10 is 0.1 mm to 0.3 mm, for example, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm or 0.3 mm.

[0072] The depth of the first groove 213 is 0.6 mm to 1.2 mm, preferably 0.8 mm to 1.0 mm. For example, the depth of the first groove 213 is 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm or 1.2 mm, etc.

[0073] There is a first gap between the first annular baffle 211 and the top cover 10, and the width of the first gap is greater than or equal to 0.02 mm, so as to ensure that the creepage distance between the first annular baffle 211 and the top cover 10 is large enough to meet the insulation requirements.

[0074] The second polymer layer 36 has a thickness of 0.7 mm to 1.5 mm, and the first polymer layer 35 has a thickness of 0.2 mm to 0.4 mm. The second polymer layer 36 and the first polymer layer 35 overlap by at least 0.1 mm in the thickness direction to ensure that the bonding strength between the second polymer layer 36 and the first polymer layer 35 meets the requirements.

[0075] In other embodiments, please refer to Figure 7 A second annular baffle 13 protrudes from the side of the top cover 10 facing the first connecting portion 21, forming a second groove 15. A first polymer layer 35 fills the second groove 15 on the top cover 10, and a portion of the first polymer layer 35 protrudes from the second annular baffle 13 in the direction facing the first connecting portion 21. A second polymer layer 36 is connected to the side of the first connecting portion 21 facing the top cover 10 and is chemically bonded to the first polymer layer 35. Thus, the first polymer layer 35 is configured such that a portion protrudes from the second annular baffle 13 in the direction facing the first connecting portion 21 to facilitate sufficient contact and chemical bonding with the second polymer layer 36 located between the first polymer layer 35 and the first connecting portion 21, ensuring that the chemical bond strength between the first polymer layer 35 and the second polymer layer 36 meets the requirements.

[0076] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0077] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A top cover assembly, characterized in that, include: The top cover (10) has a first surface (a1), a second surface (a2) and a first through hole (11), the first surface (a1) and the second surface (a2) being opposite to each other, and the first through hole (11) penetrating the first surface (a1) and the second surface (a2); The pole post (20) includes a first connecting portion (21) and a second connecting portion (22) connected to the first connecting portion (21). The first connecting portion (21) is located on the side of the top cover (10) having the first surface (a1) and is used for electrical connection with the busbar. The second connecting portion (22) passes through the first through hole (11) and is used for electrical connection with the tab. An insulating component (30) is located between the top cover (10) and the first connecting portion (21), and includes an insulating layer (31) and an adhesive layer (32); the insulating layer (31) is connected to one of the top cover (10) and the first connecting portion (21), the adhesive layer (32) is connected to the other of the top cover (10) and the first connecting portion (21), and the insulating layer (31) and the adhesive layer (32) are bonded to each other.

2. The top cover assembly according to claim 1, characterized in that, The first connecting part (21) has a first annular baffle (211) protruding on the side facing the top cover (10), and the first annular baffle (211) surrounds to form a first groove (213); The insulating layer (31) is filled in the first groove (213), and a portion of the insulating layer (31) protrudes from the first annular baffle (211) in the direction toward the top cover (10).

3. The top cover assembly according to claim 2, characterized in that, The adhesive layer (32) is coated on the side of the top cover (10) having the first surface (a1) and is located between the insulating layer (31) and the first annular baffle (211) and the top cover (10).

4. The top cover assembly according to claim 1, characterized in that, The top cover (10) has a second annular baffle (13) protruding on the side facing the first connecting part (21), and the second annular baffle (13) surrounds to form a second groove (15); The insulating layer (31) is filled in the second groove (15), and a portion of the insulating layer (31) protrudes from the second annular baffle (13) in the direction toward the first connecting portion (21).

5. The top cover assembly according to claim 4, characterized in that, The first surface (a1) of the top cover (10) is recessed to form an assembly groove, the first through hole (11) is opened in the assembly groove, the first connecting part (21) is located in the assembly groove, the second annular baffle (13) protrudes from the bottom wall of the assembly groove, and the height dimension of the second annular baffle (13) relative to the bottom wall of the assembly groove is less than or equal to the depth dimension of the assembly groove.

6. The top cover assembly according to claim 4, characterized in that, The first connecting part (21) has an annular groove (215) on the side facing the top cover (10), and the second annular baffle (13) and the annular groove (215) are opposite to each other in the thickness direction of the top cover (10).

7. A top cover assembly, characterized in that, include: The top cover (10) has a first surface (a1), a second surface (a2) and a first through hole (11), the first surface (a1) and the second surface (a2) being opposite to each other, and the first through hole (11) penetrating the first surface (a1) and the second surface (a2); The pole post (20) includes a first connecting portion (21) and a second connecting portion (22) connected to the first connecting portion (21). The first connecting portion (21) is located on the side of the top cover (10) having the first surface (a1) and is used for electrical connection with the busbar. The second connecting portion (22) passes through the first through hole (11) and is used for electrical connection with the tab. An insulating component (30) is located between the top cover (10) and the first connecting portion (21), and includes a first polymer layer (35) and a second polymer layer (36); the first polymer layer (35) is connected to the side of the top cover (10) facing the first connecting portion (21), and the second polymer layer (36) is connected to the side of the first connecting portion (21) facing the top cover (10), and the first polymer layer (35) and the second polymer layer (36) are connected by chemical bonds.

8. The top cover assembly according to claim 7, characterized in that, The first connecting portion (21) has a first annular baffle (211) protruding on the side facing the top cover (10), and the first annular baffle (211) surrounds and forms a first groove (213); the second polymer layer (36) fills the first groove (213), and a portion of the second polymer layer (36) protrudes from the first annular baffle (211) in the direction facing the top cover (10); or The top cover (10) has a second annular baffle (13) protruding on the side facing the first connecting part (21), and the second annular baffle (13) surrounds to form a second groove (15); the first polymer layer (35) fills the second groove (15), and a portion of the first polymer layer (35) protrudes from the second annular baffle (13) in the direction facing the first connecting part (21).

9. A single battery cell, characterized in that, Includes the top cover assembly as described in any one of claims 1 to 8.

10. An electrical device, characterized in that, Includes the battery cell as described in claim 9.

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