Top cover assembly, battery and electric equipment

Abstract

The utility model provides a top cover assembly, a battery and electric equipment. Comprising a top cover, a pole, upper plastic and a sealing ring, the top cover comprises a first surface and a second surface which are oppositely arranged, the top cover is provided with a first hole and a first mounting groove which are coaxially arranged and communicated, and the first hole penetrates through the first surface and the second surface; the pole penetrates through the first hole; the upper plastic comprises an upper plastic body and a convex part which are connected and sleeve the outer side of the pole, the upper plastic body is mounted in the first mounting groove, the convex part is mounted in the first hole, the outer surface of the convex part comprises a guide inclined surface, a first transition cambered surface and a bottom surface, and the bottom surface is an end surface of one end, far away from the upper plastic body, of the convex part; the first transition cambered surface is bent and connected between the guide inclined surface and the bottom surface; the sealing ring sleeves the outer side of the pole, part of the sealing ring is positioned in the first hole and is in interference fit with the convex part, and the sealing ring positioned in the first hole is also in contact with the bottom surface and the first transition cambered surface. According to the technical scheme, conduction of the top cover and the pole can be avoided, and the safety performance of the electrode assembly is guaranteed.

Description

Technical Field

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

[0002] With the development of green energy and the increasing environmental awareness of people, the application of recyclable batteries is becoming more and more widespread. A battery includes electrode components, a casing, and a top cover assembly. The electrode components are located within the space enclosed by the casing and top cover assembly. The top cover assembly includes a top cover and terminals. The terminals are mounted on the top cover. Currently, electrolyte can easily seep in through gaps between the top cover and the terminals, which reduces the insulation between them, potentially leading to conductivity issues and a decrease in the safety performance of the electrode components. Utility Model Content

[0003] Embodiments of this application provide a top cover assembly, a battery, and an electrical device that can prevent the top cover and the terminal posts from conducting, thus ensuring the safety performance of the electrode assembly.

[0004] In a first aspect, this application provides a top cover assembly, the top cover assembly comprising:

[0005] A top cover, comprising a first surface and a second surface, the first surface and the second surface being disposed opposite to each other in the thickness direction of the top cover, the top cover having a first hole and a first mounting groove, the first hole penetrating through the first surface and the second surface, the opening of the first mounting groove being located on the first surface, and the first mounting groove being coaxially disposed with and connected to the first hole;

[0006] A terminal post, wherein the terminal post passes through the first hole;

[0007] An upper plastic body, comprising a connected upper plastic body and a protrusion, both the upper plastic body and the protrusion being sleeved on the outside of the pole post. The upper plastic body is installed in the first mounting groove, and the protrusion is installed in the first hole. The outer surface of the protrusion includes a guide slope, a first transition arc surface, and a bottom surface. The bottom surface is the end face of the protrusion away from the upper plastic body. In the direction from the upper plastic body toward the protrusion, the distance between the guide slope and the hole wall of the first hole gradually increases. The first transition arc surface bends and connects the guide slope and the bottom surface.

[0008] A sealing ring is fitted on the outside of the pole post. Part of the sealing ring is located inside the first hole and is interference-fitted with the end of the protrusion away from the upper plastic body. The sealing ring located inside the first hole is also in contact with the bottom surface and the first transition arc surface.

[0009] Understandably, in related technologies, after the assembled top cover assembly comes into contact with the electrolyte, the electrolyte can seep into the area where the electrode post of the top cover assembly is located. Due to manufacturing tolerances and assembly tolerances of the components in the top cover assembly, gaps will form between the top cover and the electrode post. When electrolyte is present in these gaps, the insulation performance between the top cover and the electrode post can be drastically reduced, thus decreasing the safety of the electrode assembly.

[0010] Therefore, by placing both the upper plastic and the sealing ring within the gap between the top cover and the electrode post, and ensuring that the sealing ring in this gap is interference-fitted with the upper plastic, the upper plastic and the sealing ring can effectively seal the gap between the top cover and the electrode post, blocking the electrolyte flow path and preventing short circuits caused by contact between the electrode post and the top cover with the electrolyte. This improves the safety performance of the electrode assembly.

[0011] In addition, by forming a guide slope at the end of the protrusion away from the upper plastic body, the protrusion can be quickly slid into the first hole of the top cover during the assembly of the upper plastic and the top cover, thereby realizing the rapid assembly between the upper plastic and the top cover, reducing the assembly time of the top cover assembly and improving the assembly efficiency of the top cover assembly.

[0012] In addition, since there is a first transition arc surface connecting the guide slope and the bottom surface, the transition between the guide slope and the bottom surface can be softened by the first transition arc surface, effectively avoiding stress concentration, improving the strength of the upper plastic, and preventing the upper plastic from scratching the sealing ring due to collision with the sealing ring during the assembly of the top cover assembly. This further improves the assembly performance of the top cover assembly and ensures the insulation performance between the top cover and the pole and the safety performance of the electrode assembly.

[0013] In one possible implementation, a first gap is formed between the guide bevel and the inner wall of the first hole, and a portion of the sealing ring is located within the first gap and covers at least a portion of the guide bevel.

[0014] In one possible implementation, the outer surface of the protrusion further includes an outer side surface and a second transition arc surface, the outer side surface being disposed opposite to the inner wall of the first hole, and the second transition arc surface being bent and connected between the outer side surface and the guide slope.

[0015] In one possible implementation, the upper plastic is provided with a first through hole, which penetrates the upper plastic body and the protrusion along the thickness direction of the upper plastic, and the pole post passes through the first through hole;

[0016] The outer surface of the protrusion also includes a third transition arc surface, which is bent and connected between the bottom surface and the inner wall of the first through hole. The third transition arc surface also contacts the sealing ring located in the first hole.

[0017] In one possible implementation, a fourth transition arc surface connects the bottom wall of the first mounting groove and the inner wall of the first hole, and the connection between the upper plastic body and the protrusion is opposite to the fourth transition arc surface.

[0018] In one possible implementation, the interference fit between the sealing ring and the upper plastic in the thickness direction of the top cover assembly is in the range of 0.1 mm to 0.3 mm.

[0019] In one possible implementation, the top cover assembly further includes a lower plastic layer, which is stacked with the top cover. The lower plastic layer has a second hole that penetrates the lower plastic layer along its thickness direction and communicates with the first hole.

[0020] The pole includes a column and a base. The column passes through the first hole, the second hole and the upper plastic. The base is coaxially arranged with and connected to the column. The base is located on the side of the lower plastic facing away from the top cover and forms a second gap with the lower plastic.

[0021] The sealing ring is fitted onto the column and located within the first hole, the second hole, the first gap, and the second gap. The sealing ring located within the second gap is interference-fitted with the lower plastic in the thickness direction of the top cover assembly.

[0022] In one possible implementation, the lower plastic is provided with a thinning groove, the opening of the thinning groove is located on the surface of the lower plastic away from the top cover, the thinning groove is coaxially arranged and connected with the second hole, and the thinning groove forms part of the second gap.

[0023] In one possible implementation, the distance between the bottom wall of the thinning groove and the surface of the lower plastic facing the top cover is in the range of 0.1mm-0.7mm.

[0024] In one possible implementation, the sealing ring is in contact with the inner wall of the first hole, the inner wall of the second hole, the bottom wall of the thinning groove, and the portion of the top cover facing the lower plastic. The sealing ring located in the first hole is interference-fitted with the top cover in the radial direction of the sealing ring, and the sealing ring located in the second hole is interference-fitted with the lower plastic in the radial direction of the sealing ring.

[0025] In one possible implementation, the overlap length between the sealing ring and the lower plastic in the longitudinal direction of the top cover assembly is greater than or equal to 0.2 mm.

[0026] Secondly, this application also provides a battery, the battery including an electrode assembly, a housing and a top cover assembly as described above, the top cover assembly being connected to the housing and forming a receiving space with the housing, the electrode assembly being located within the receiving space.

[0027] Thirdly, this application also provides an electrical device, which includes the battery described above. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the energy storage system provided in an embodiment of this application;

[0029] Figure 2 This is a schematic diagram of a battery structure provided in an embodiment of this application;

[0030] Figure 3 This is a schematic diagram of the structure of the top cover assembly provided in an embodiment of this application;

[0031] Figure 4 yes Figure 3 The exploded view of the top cover assembly is shown.

[0032] Figure 5a yes Figure 3 A schematic diagram of the top cover assembly at one angle;

[0033] Figure 5b yes Figure 5a An enlarged schematic diagram of region B is shown below;

[0034] Figure 6 yes Figure 3 A schematic diagram of the top cover assembly from another angle;

[0035] Figure 7 It is along Figure 3 A schematic cross-sectional view of a partial structure obtained by cutting along section line AA;

[0036] Figure 8 yes Figure 3 A schematic diagram of the structure of the lower plastic of the top cover assembly at one angle;

[0037] Figure 9 yes Figure 3 A schematic diagram of the structure of the lower plastic of the top cover assembly from another angle;

[0038] Figure 10 It is along Figure 3A schematic cross-sectional view of another part of the structure obtained by cutting along section line AA.

[0039] Figure 11 yes Figure 3 A schematic diagram of the structure of the pole of the top cover assembly at one angle;

[0040] Figure 12 yes Figure 3 A schematic diagram of the structure of the upper plastic part of the top cover assembly at one angle;

[0041] Figure 13a yes Figure 3 A schematic diagram of the upper plastic of the top cover assembly from another angle;

[0042] Figure 13b yes Figure 13a An enlarged schematic diagram of region C is shown below;

[0043] Figure 14 yes Figure 10 An enlarged schematic diagram of region E is shown below;

[0044] Figure 15 yes Figure 3 A schematic diagram of the structure of the pressure ring of the top cover assembly at one angle;

[0045] Figure 16 yes Figure 3 The diagram shows a structural schematic of the sealing ring at one angle of the top cover assembly.

[0046] Figure label:

[0047] Energy storage system 400, power conversion device 410, first user load 420, second user load 430, electrical equipment 300, battery 200, top cover assembly 100, housing 210, electrode assembly 220, top cover 10, upper plastic 20, lower plastic 30, electrode post 40, sealing ring 50, pressure ring 60, limiting body 70, explosion-proof valve assembly 80, first surface 101, second surface 102, first hole 11, first mounting groove 12, fourth transition arc surface 19, first limiting hole 13, first injection hole 14, explosion-proof hole 15, mounting platform 16, groove 17, positioning hole 18, explosion-proof valve 81, explosion-proof valve protection plate 82, third surface 301, fourth surface 302 Second hole 31, positioning post 32, thinning groove 33, post 41, base 42, first sub-post 411, second sub-post 412, cross-sectional width D2 of the first sub-post 411 along the height direction of the pole post 40, cross-sectional width D3 of the second sub-post 412 along the height direction of the pole post 40, cross-sectional width D1 of the base 42 along the height direction of the pole post 40, second gap W2, upper plastic body 21, protrusion 22, outer side 222, guide slope 221, first transition arc surface 223, second transition arc surface 225, bottom surface 224, first through hole 23, second mounting groove 211, second through hole 61, second limiting hole 62, first gap W1, first sub-part 51, second sub-part 52. Detailed Implementation

[0048] For ease of understanding, the terminology used in the embodiments of this application will be explained first.

[0049] And / or: This is simply a way of describing the relationship between related objects. It indicates that there can be three kinds of relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0050] Multiple: refers to two or more.

[0051] Connection: should be interpreted broadly. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through an intermediary.

[0052] The specific embodiments of this application will now be clearly described in conjunction with the accompanying drawings.

[0053] Embodiments of this application provide a top cover assembly, a battery, and an electrical device.

[0054] Because the energy we need is highly time- and space-dependent, in order to utilize energy rationally and improve energy efficiency, it is necessary to store one form of energy in the same way or by converting it into another, and then release it in a specific energy form according to future application needs. As we all know, the generation of green electricity currently relies heavily on photovoltaic, wind, and hydropower. However, wind and solar energy are generally characterized by strong intermittency and large fluctuations, which can cause grid instability, insufficient power during peak demand periods, and excessive power during off-peak periods. Unstable voltage can also damage the power grid. Therefore, insufficient electricity demand or insufficient grid capacity can lead to the problem of "wind and solar curtailment." Solving these problems requires energy storage. This involves converting electrical energy into other forms of energy through physical or chemical means and storing it, then releasing the stored energy as electricity when needed. Simply put, energy storage is like a large "power bank," storing electrical energy when photovoltaic and wind power are abundant and releasing the stored electricity when needed.

[0055] Taking electrochemical energy storage as an example, the embodiments of this application provide an electrical device. The electrical device is equipped with a set of chemical batteries. It mainly uses the chemical elements in the chemical batteries as energy storage medium. The charging and discharging process is accompanied by the chemical reaction or change of the energy storage medium. Simply put, it stores the electrical energy generated by wind and solar energy in the chemical batteries. When the use of external electrical energy reaches its peak, the stored electricity is released for use, or transferred to places with a shortage of electricity for use.

[0056] Current energy storage applications are quite widespread, including generation-side energy storage, grid-side energy storage, renewable energy grid-connected energy storage, and user-side energy storage. The corresponding types of electrical equipment include:

[0057] Large energy storage containers used in grid-side energy storage scenarios can serve as high-quality active and reactive power regulation power sources in the power grid, enabling load matching of electrical energy in time and space, enhancing the absorption capacity of renewable energy, and playing a significant role in grid system backup, alleviating peak load power supply pressure, and peak shaving and frequency regulation.

[0058] Small and medium-sized energy storage cabinets used in commercial and industrial energy storage scenarios on the user side, and small residential energy storage boxes used in home energy storage scenarios on the user side, mainly operate under the "peak shaving and valley filling" mode. Because there are significant price differences in electricity during peak and off-peak periods based on electricity demand, users typically charge the energy storage cabinets / boxes during off-peak hours to reduce costs; then, during peak hours, they release the electricity from the devices for use, thus saving on electricity bills. Furthermore, in remote areas and regions prone to natural disasters such as earthquakes and hurricanes, the presence of household electrical appliances effectively provides users with backup power for themselves and the power grid, avoiding the inconvenience caused by frequent power outages due to disasters or other reasons.

[0059] Please see Figure 1 , Figure 1 This is a schematic diagram of the energy storage system 400 provided in an embodiment of this application. This embodiment uses a home energy storage scenario in user-side energy storage as an example for illustration; however, the electrical equipment 300 in this application is not limited to a home energy storage scenario.

[0060] This application provides an energy storage system 400, which includes a power conversion device 410, a first user load 420, a second user load 430, and an electrical appliance 300. The electrical appliance 300 is a small energy storage box that can be wall-mounted on an outdoor wall. Specifically, photovoltaic panels can convert solar energy into electrical energy during periods of low electricity prices, and the electrical appliance 300 stores this electrical energy to supply streetlights and household appliances during peak electricity prices, or to provide power during power outages.

[0061] The electrical device 300 may include, but is not limited to, individual batteries, battery modules, battery packs, and battery systems. When the electrical device 300 includes multiple batteries 200, the multiple batteries 200 are electrically connected and all are located inside the casing of the electrical device 300, which protects them from interference from the external environment. Exemplarily, the multiple batteries 200 are arranged at intervals. The multiple batteries 200 can be connected in series, in parallel, or in a combination of series and parallel connections to achieve greater capacity and power. The embodiments of this application are illustrated using the example of an electrical device 300 including batteries 200, but it should be understood that the electrical device 300 is not limited thereto.

[0062] Please see Figure 2 , Figure 2 This is a schematic diagram of a battery 200 provided in an embodiment of this application.

[0063] For ease of description, the length direction of battery 200 is defined as the X direction, the width direction as the Y direction, and the height direction as the Z direction. The X, Y, and Z directions are all perpendicular to each other.

[0064] Battery 200 may include a top cover assembly 100, a housing 210, and an electrode assembly 220. The top cover assembly 100 is connected to the housing 210 and forms a receiving space with the housing 210, within which the electrode assembly 220 is located. Exemplarily, the top cover assembly 100 may be welded to the housing 210. The housing 210 may be made of a metallic material, such as aluminum alloy. Battery 200 may be a cylindrical battery 200 or a prismatic battery 200, etc.

[0065] The electrode assembly 220 may include at least two electrode cores (not shown). The at least two electrode cores are arranged sequentially along the thickness direction of the battery 200. The arrangement of multiple electrode cores can increase the capacity of the battery 200, thereby allowing the battery 200 to be used for a longer period of time, and thus increasing the applicable scenarios of the battery 200. Each electrode core may include a winding core, a first tab, and a second tab. Both the first tab and the second tab are connected to the winding core. The first tab and the second tab have opposite polarities, one being a positive tab and the other a negative tab.

[0066] It should be noted that, Figure 2 The purpose is merely to illustratively describe the connection relationship between the top cover assembly 100, the housing 210, and the electrode assembly 220, and is not to specifically limit the connection positions, specific structures, or quantities of each component. Furthermore, the structures illustrated in the embodiments of this application do not constitute a specific limitation on the battery 200. In other embodiments of this application, the battery 200 may include components such as... Figure 2 This may involve more or fewer components, or combining certain components, or splitting certain components, or different component arrangements. Figure 2 The components shown can be implemented in hardware, software, or a combination of both.

[0067] Please refer to the following: Figure 3 and Figure 4 , Figure 3 This is a schematic diagram of the structure of the top cover assembly 100 provided in an embodiment of this application. Figure 4 yes Figure 3 The exploded structural diagram of the top cover assembly 100 shown.

[0068] The top cover assembly 100 may include a top cover 10, an upper plastic 20, a lower plastic 30, a terminal post 40, a sealing ring 50, a pressure ring 60, a limiting body 70, and an explosion-proof valve assembly 80. The upper plastic 20 is mounted on one side of the top cover 10 in the thickness direction (Z direction in the diagram), and the lower plastic 30 is mounted on the other side of the top cover 10 in the thickness direction, with the lower plastic 30 and the upper plastic 20 protruding from opposite surfaces of the top cover 10 in the thickness direction, respectively. The terminal post 40 is mounted on the top cover 10, the upper plastic 20, and the lower plastic 30, and is insulated from the top cover 10 by the upper plastic 20 and the lower plastic 30. The terminal post 40 can also serve as an electrode lead-out of the battery 200 to achieve electrical connection between the battery 200 and an external device. The sealing ring 50 is sleeved on the outside of the terminal post 40 and is located between the lower plastic 30 and the terminal post 40, as well as between the top cover 10 and the terminal post 40. The sealing ring 50 is used to seal the gap between the top cover 10 and the terminal post 40, preventing electrolyte from entering and reducing the insulation between the top cover 10 and the terminal post 40, as well as the safety of the electrode assembly 220. The pressure ring 60 is mounted on the upper plastic 20 and sleeved on the outside of the terminal post 40, and is electrically connected to the terminal post 40. The limiting body 70 passes through the upper plastic 20 and is located between the pressure ring 60 and the top cover 10. The explosion-proof valve assembly 80 is mounted on the top cover 10 and is used for pressure relief protection of the battery 200.

[0069] The top cover 10 can have two upper plastic inserts 20, spaced apart on both sides along its length (X direction in the diagram). It can also have two pressure rings 60, each mounted on one of the upper plastic inserts 20. It can have two terminals 40, one a negative terminal and the other a positive terminal. These terminals 40 can be spaced apart along the length of the top cover 10. Each terminal 40 is mounted on the lower plastic insert 30, the top cover 10, one upper plastic insert 20, and one pressure ring 60. It can have two sealing rings 50, one fitted onto the positive terminal and the other onto the negative terminal. It can have multiple limiting bodies 70, spaced apart and passing through the two upper plastic inserts 20, located between the top cover 10 and the two pressure rings 60.

[0070] The following description will use the structure of the top cover 10, lower plastic 30, upper plastic 20, pressure ring 60, pole post 40, sealing ring 50, and limiting body 70 as examples to illustrate the components in the top cover assembly 100. Unless otherwise specified, the descriptions of the structure of one upper plastic 20, one pressure ring 60, one pole post 40, one sealing ring 50, and one limiting body 70 can be applied to other upper plastic 20s, pressure rings 60s, pole posts 40s, sealing rings 50s, and limiting bodies 70.

[0071] Please refer to the following: Figure 5a and Figure 5b , Figure 5a yes Figure 3 The diagram shows a structural schematic of the top cover 10 of the top cover assembly 100 at one angle. Figure 5b yes Figure 5a An enlarged schematic diagram of region B is shown.

[0072] The top cover 10 may include a first surface 101 and a second surface 102. The second surface 102 and the first surface 101 are disposed opposite to each other in the thickness direction of the top cover 10. The first surface 101 may face away from the electrode assembly 220, and the second surface 102 may face the electrode assembly 220.

[0073] The top cover 10 may have a first hole 11 and a first mounting groove 12. The first hole 11 may penetrate the top cover 10 along its thickness direction. That is, the first hole 11 may penetrate the first surface 101 and the second surface 102. The opening of the first mounting groove 12 may be located on the first surface 101. The first mounting groove 12 may be recessed from the first surface 101 into the interior of the top cover 10. The first mounting groove 12 may be coaxially arranged with and connected to the first hole 11. The cross-sectional width of the first mounting groove 12 along the thickness direction of the top cover 10 may be greater than the cross-sectional width of the first hole 11 along the thickness direction of the top cover 10.

[0074] For example, there can be two first holes 11. The two first holes 11 can be spaced apart along the length of the top cover 10. There can also be two first mounting slots 12. The two first mounting slots 12 can be spaced apart along the length of the top cover 10. Each first mounting slot 12 is coaxially arranged with and communicates with a first hole 11. The first hole 11 can be a cylindrical hole. The first mounting slot 12 can be a hexagonal blind slot.

[0075] A fourth transition arc surface 19 connects the bottom wall of the first mounting groove 12 and the inner wall of the first hole 11. The bottom wall and opening of the first mounting groove 12 are positioned opposite each other in the thickness direction of the top cover 10. The fourth transition arc surface 19 can be an annular arc surface and is arranged around the outer edge of the first hole 11. The fourth transition arc surface 19 can be bent towards the central axis of the first hole 11.

[0076] The top cover 10 may be provided with a first limiting hole 13. The opening of the first limiting hole 13 may be located on the bottom wall of the first mounting groove 12. The first limiting hole 13 may be formed by recessing from the bottom wall of the first mounting groove 12 into the interior of the top cover 10. The first limiting hole 13 may be located on the outer edge of the first hole 11. The first limiting hole 13 is a blind hole. There may be multiple first limiting holes 13. The structures of the multiple first limiting holes 13 may be similar, identical, or different. The multiple first limiting holes 13 may be spaced apart on the bottom wall of the first mounting groove 12. Furthermore, the multiple first limiting holes 13 may also be spaced apart along the circumferential direction of the first hole 11.

[0077] For example, the number of first limiting holes 13 can be six. Of the six first limiting holes 13, three first limiting holes 13 can be spaced apart on the bottom wall of one of the first mounting grooves 12, and the other three first limiting holes 13 can be spaced apart on the bottom wall of the other first mounting groove 12.

[0078] The top cover 10 may be provided with an explosion-proof hole 15. The explosion-proof hole 15 penetrates the top cover 10 along the thickness direction. For example, the first injection hole 14 and the explosion-proof hole 15 may both be located between the two first mounting grooves 12.

[0079] Please refer to the following: Figure 5a and Figure 6 , Figure 6 yes Figure 3 A structural schematic diagram of the top cover 10 of the top cover assembly 100 from another angle.

[0080] The top cover 10 may be provided with a mounting platform 16 and a recess 17. The mounting platform 16 may be disposed on the first surface 101 and protrude in a direction away from the top cover 10 relative to the first surface 101. The mounting platform 16 may also be disposed around the outer edge of the explosion-proof hole 15. The opening of the recess 17 may be located on the second surface 102. The recess 17 may be recessed from the second surface 102 into the interior of the top cover 10. The recess 17 may be coaxially disposed with and communicate with the explosion-proof hole 15.

[0081] The top cover 10 may be provided with positioning holes 18. The opening of the positioning hole 18 may be located on the second surface 102. The positioning hole 18 may be recessed from the second surface 102 into the interior of the top cover 10. The positioning hole 18 may be a blind hole. There may be multiple positioning holes 18. The structures of the multiple positioning holes 18 may be similar, identical, or different. The multiple positioning holes 18 may be spaced apart on the top cover 10. For example, there may be four positioning holes 18. The four positioning holes 18 are respectively located at the four corners of the top cover 10.

[0082] Please see Figure 7 , Figure 7 It is along Figure 3 The diagram shows a cross-sectional view of a partial structure obtained by cutting along section line AA.

[0083] The explosion-proof valve assembly 80 may include an explosion-proof valve 81 and an explosion-proof valve protection plate 82. Both the explosion-proof valve 81 and the explosion-proof valve protection plate 82 may be mounted on the top cover 10 and arranged sequentially along the thickness direction of the top cover 10. Specifically, the explosion-proof valve 81 may be located in the groove 17 of the top cover 10 and cover the opening of the explosion-proof hole 15 on the second surface 102 of the top cover 10. The explosion-proof valve protection plate 82 may be connected to the mounting platform 16 of the top cover 10 and cover the opening of the explosion-proof hole 15 on the first surface 101 of the top cover 10. The explosion-proof valve protection plate 82 may also cover the explosion-proof valve 81.

[0084] Please refer to the following: Figure 3 and Figure 8 , Figure 8 yes Figure 3 A schematic diagram of the structure of the lower plastic 30 of the top cover assembly 100 at an angle.

[0085] The lower plastic 30 can be stacked with the top cover 10 and includes a third surface 301 and a fourth surface 302. The fourth surface 302 and the third surface 301 can be disposed opposite to each other in the thickness direction of the lower plastic 30. The third surface 301 can face the top cover 10, and the fourth surface 302 can face the electrode assembly 220.

[0086] The lower plastic 30 may have a second hole 31. The second hole 31 may penetrate the lower plastic 30 along its thickness direction (Z direction in the figure) and communicate with the first hole 11 of the top cover 10. That is, the second hole 31 may penetrate the third surface 301 and the fourth surface 302. Exemplarily, there may be two second holes 31. The two second holes 31 may be spaced apart along the length direction of the lower plastic 30 (X direction in the figure). Each second hole 31 communicates with one of the first holes 11 of the top cover 10.

[0087] The lower plastic 30 may be provided with positioning posts 32. The positioning posts 32 may be located on the third surface 301 and protrude towards the top cover 10 relative to the third surface 301. The positioning posts 32 may be installed in the positioning holes 18 of the top cover 10 to achieve a fixed connection between the lower plastic 30 and the top cover 10. The shape of the positioning posts 32 may be adapted to the shape of the positioning holes 18 of the top cover 10. There may be multiple positioning posts 32. The structures of the multiple positioning posts 32 may be similar, identical, or different. The multiple positioning posts 32 may be spaced apart on the lower plastic 30. For example, there may be four positioning posts 32. The four positioning posts 32 are respectively located at the four corners of the lower plastic 30. Each positioning post 32 is installed in one positioning hole 18 of the top cover 10.

[0088] Please refer to the following: Figure 8 and Figure 9 , Figure 9 yes Figure 3A structural schematic diagram of the lower plastic 30 of the top cover assembly 100 from another angle.

[0089] The lower plastic 30 may be provided with a thinning groove 33. The opening of the thinning groove 33 may be located on the fourth surface 302. The thinning groove 33 may be formed by recessing from the fourth surface 302 into the interior of the lower plastic 30. The thinning groove 33 may be coaxially arranged and connected with the second hole 31. Exemplarily, there may be two thinning grooves 33. The two thinning grooves 33 may be spaced apart in the length direction of the lower plastic 30. Each thinning groove 33 is coaxially arranged and connected with a second hole 31.

[0090] It is understandable that by setting the thinning groove 33, the thickness of the lower plastic 30 can be reduced while ensuring the strength of the lower plastic 30, thus reducing its weight and facilitating the miniaturization and thinning of the top cover assembly 100.

[0091] The distance between the bottom wall of the thinning groove 33 and the third surface 301 of the lower plastic 30 can be in the range of 0.1mm-0.7mm (inclusive of the endpoint values ​​of 0.1mm and 0.7mm). The bottom wall of the thinning groove 33 can be positioned opposite to the opening of the thinning groove 33 in the thickness direction of the lower plastic 30. For example, the distance between the bottom wall of the thinning groove 33 and the third surface 301 of the lower plastic 30 can be 0.3mm.

[0092] Understandably, if the distance between the bottom wall of the thinning groove 33 and the third surface 301 of the lower plastic 30 is less than 0.1 mm, the lower plastic 30 will lack Z-axis load-bearing capacity at the location where the thinning groove 33 is located, potentially leading to failure of the top cover assembly 100. Furthermore, it will increase the manufacturing difficulty of the lower plastic 30. If the distance between the bottom wall of the thinning groove 33 and the third surface 301 of the lower plastic 30 is greater than 0.7 mm, the stepped wall of the lower plastic 30 will be too thin, resulting in a significant decrease in the sealing performance between the lower plastic 30 and the sealing ring 50 during assembly. Therefore, setting the distance between the bottom wall of the thinning groove 33 and the third surface 301 of the lower plastic 30 between 0.1 mm and 0.7 mm effectively avoids the aforementioned problems and improves the operational reliability of the top cover assembly 100.

[0093] Please refer to the following: Figure 10 and Figure 11 , Figure 10 It is along Figure 3 The diagram shows a cross-sectional view of another part of the structure obtained by cutting along section line AA. Figure 11 yes Figure 3 A schematic diagram of the structure of the pole post 40 of the top cover assembly 100 at an angle.

[0094] The pole post 40 may include a post body 41 and a base 42. The post body 41 and the base 42 may be coaxially arranged and connected. The post body 41 may pass through the first hole 11 of the top cover 10 and the second hole 31 of the lower plastic 30. Part of the post body 41 may protrude in a direction away from the top cover 10 relative to the first surface 101 of the top cover 10. Specifically, the post body 41 may include a first sub-post 411 and a second sub-post 412. The first sub-post 411 and the second sub-post 412 may be coaxially arranged and connected. The first sub-post 411 may be connected between the second sub-post 412 and the base 42. That is, in the height direction of the pole post 40, the base 42, the first sub-post 411 and the second sub-post 412 may be connected in sequence. The cross-sectional width D2 of the first sub-post 411 along the height direction of the pole post 40 (Z direction in the figure) may be greater than the cross-sectional width D3 of the second sub-post 412 along the height direction of the pole post 40, and less than the cross-sectional width D1 of the base 42 along the height direction of the pole post 40. That is, the projection of the column 41 along the height direction of the pole column 40 can fall entirely onto the base 42. The first sub-column 411 can be located in the first hole 11 of the top cover 10 and the second hole 31 of the lower plastic 30. Part of the second sub-column 412 can be located in the first hole 11 of the top cover 10, and the remaining part of the second sub-column 412 can be protruding relative to the first surface 101 of the top cover 10.

[0095] The base 42 can be located on the side of the lower plastic 30 facing away from the top cover 10 (i.e., on the side of the fourth surface 302 of the lower plastic 30), forming a second gap W2 between it and the lower plastic 30. The second gap W2 can be arranged around the column 41. That is, in the thickness direction (Z direction in the figure) of the top cover assembly 100, the second gap W2 can be located between the top cover 10 and the lower plastic 30, and surround the outside of the column 41. The projection of the base 42 onto the lower plastic 30 along the thickness direction (Z direction in the figure) of the top cover assembly 100 can partially fall into the lower plastic 30. That is, in the thickness direction of the top cover assembly 100, there can be a certain overlap between the base 42 and the lower plastic 30.

[0096] Please refer to the following: Figure 10 , Figure 12 and Figure 13a , Figure 12 yes Figure 3 The diagram shows a structural schematic of the upper plastic 20 of the top cover assembly 100 at an angle. Figure 13a yes Figure 3 A structural schematic diagram of the upper plastic 20 of the top cover assembly 100 from another angle.

[0097] The upper plastic 20 can be sleeved on the pole post 40 and located between the top cover 10 and the pole post 40. Specifically, the upper plastic 20 may include an upper plastic body 21 and a protrusion 22. The upper plastic body 21 may be coaxially arranged and connected to the protrusion 22. The cross-sectional width of the upper plastic body 21 along the thickness direction (X direction in the figure) of the upper plastic 20 may be greater than the cross-sectional width of the protrusion 22 along the thickness direction of the top cover 10.

[0098] The upper plastic 20 may be provided with a first through hole 23. The first through hole 23 can penetrate the upper plastic 20 along the thickness direction (Z direction in the figure). That is, the first through hole 23 can penetrate the upper plastic body 21 and the protrusion 22 along the thickness direction of the upper plastic 20. Among them, a portion of the first sub-post 411 and at least a portion of the second sub-post 412 of the pole post 40 can be located within the first through hole 23.

[0099] The upper plastic body 21 can be installed in the first mounting groove 12 of the top cover 10. Part of the upper plastic body 21 is located in the first mounting groove 12 of the top cover 10, and the remaining part of the upper plastic body 21 protrudes from the first surface 101 of the top cover 10 in a direction away from the lower plastic 30. That is, the upper plastic body 21 can be located on the side of the top cover 10 away from the lower plastic 30, and is also sleeved on the outside of the post 41 of the pole post 40.

[0100] The upper plastic body 21 may be provided with a second mounting groove 211. The opening of the second mounting groove 211 may be located on the surface of the upper plastic body 21 opposite to the protrusion 22. The second mounting groove 211 may be formed by recessing from the surface of the upper plastic body 21 opposite to the protrusion 22 of the upper plastic 20. The second mounting groove 211 may be coaxially arranged with the first through hole 23. The cross-sectional width of the second mounting groove 211 along the thickness direction of the upper plastic 20 may be greater than the cross-sectional width of the first through hole 23 along the thickness direction of the top cover 10.

[0101] For example, there can be two first through holes 23. The two first through holes 23 can be respectively provided on two upper plastic 20s. There can also be two second mounting slots 211. The two second mounting slots 211 can be respectively provided on two upper plastic 20s. Each second mounting slot 211 is coaxially disposed with and connected to one of the first through holes 23.

[0102] Please refer to the following: Figure 13a , Figure 13b and Figure 14 , Figure 13b yes Figure 13a The enlarged schematic diagram of region C shown is shown below. Figure 14 yes Figure 10 An enlarged schematic diagram of region E is shown.

[0103] One end of the protrusion 22 is fixedly connected to the upper plastic body 21, and the other end of the protrusion 22 extends away from the upper plastic body 21. The protrusion 22 can be located in the first hole 11 of the top cover 10, and also surrounds the outside of the column 41 of the pole post 40. The connection between the protrusion 22 and the upper plastic body 21 is opposite to the fourth transition arc surface 19 of the top cover 10.

[0104] The outer surface of the protrusion 22 may include an outer surface 222, a guide slope 221, a first transition arc surface 223, a second transition arc surface 225, and a bottom surface 224. Among them, the outer surface 222, the guide slope 221, the first transition arc surface 223, the second transition arc surface 225, and the bottom surface 224 may all be toroidal surfaces.

[0105] The outer surface 222 is positioned opposite to the inner wall of the first hole 11 of the top cover 10. The bottom surface 224 is the end face of the protrusion 22 away from the upper plastic body 21. A first transition arc surface 223 is bent and connected between the guide slope 221 and the bottom surface 224, and a second transition arc surface 225 is bent and connected between the outer surface 222 and the guide slope 221. That is, the second transition arc surface 225, the guide slope 221, and the first transition arc surface 223 are sequentially connected between the outer surface 222 and the bottom surface 224. In other words, the guide slope 221 has a first transition arc surface 223 and a second transition arc surface 225 at opposite ends along the thickness direction (Z direction in the figure). The first transition arc surface 223 and the second transition arc surface 225 can both be bent away from the central axis of the upper plastic 20, and the guide slope 221 can be inclined from the top cover 10 towards the pole post 40. In the direction from the upper plastic body 21 toward the protrusion 22, the distance between the guide slope 221 and the wall of the first hole 11 gradually increases. A first gap W1 can be formed between the guide slope 221 and the inner wall of the first hole 11. Exemplarily, the guide slope 221 can be disposed around the end of the protrusion 22 away from the upper plastic body 21 in the circumferential direction of the protrusion 22.

[0106] It is understandable that by forming a guide slope 221 at the end of the protrusion 22 away from the upper plastic body 21, the protrusion 22 can be quickly slid into the first hole 11 of the top cover 10 by the guiding effect of the guide slope 221 when the upper plastic 20 is assembled with the top cover 10, thereby realizing the rapid assembly between the upper plastic 20 and the top cover 10, reducing the assembly time of the top cover assembly 100 and improving the assembly efficiency of the top cover assembly 100.

[0107] Furthermore, the fourth transition arc surface 19 connecting the bottom wall of the first mounting groove 12 and the inner wall of the first hole 11 softens the edges of the top cover 10. Therefore, when the upper plastic 20 is assembled with the top cover 10, the top cover 10 will not scratch the upper plastic 20, improving the assembly performance of the upper plastic 20. In addition, since the guide slope 221 has a first transition arc surface 223 and a second transition arc surface 225 at opposite ends along the thickness direction of the upper plastic 20, the guide slope 221 can be softened by the first transition arc surface 223 and the second transition arc surface 225 at opposite ends along the thickness direction of the upper plastic 20, effectively avoiding stress concentration, improving the strength of the upper plastic 20, and preventing the upper plastic 20 from scratching the sealing ring 50 due to collision with it during the assembly of the top cover assembly 100. This further improves the assembly performance of the top cover assembly 100 and ensures the insulation performance between the top cover 10 and the electrode post 40 and the safety performance of the electrode assembly 220.

[0108] In one possible implementation, the outer surface of the protrusion 22 further includes a third transition arc surface. The third transition arc surface bends between the bottom surface 224 and the inner wall of the first through hole 23. The third transition arc surface also contacts the sealing ring 50 located in the first hole 11.

[0109] It is understandable that by setting a third transition arc surface between the bottom surface 224 and the inner wall of the first through hole 23, and making the third transition arc surface contact the sealing ring 50 located in the first hole 11, the sharp edges of the sealing ring 50 can be further softened, effectively avoiding stress concentration, improving the strength of the upper plastic 20, and preventing the upper plastic 20 from scratching the sealing ring 50 due to collision with the sealing ring 50 during the assembly of the top cover assembly 100. This further improves the assembly performance of the top cover assembly 100 and ensures the insulation performance between the top cover 10 and the pole post 40 and the safety performance of the electrode assembly 220.

[0110] Please refer to the following: Figure 10 and Figure 15 , Figure 15 yes Figure 3 A schematic diagram of the structure of the pressure ring 60 of the top cover assembly 100 at one angle.

[0111] The pressure ring 60 can be installed in the second mounting groove 211 of the upper plastic body 21 and sleeved on the outside of the post 41 of the pole post 40, and electrically connected to the pole post 40. Part of the pressure ring 60 can be located in the second mounting groove 211 of the upper plastic body 21, and the remaining part of the pressure ring 60 can be protruding from the surface of the upper plastic body 21 away from the protrusion 22 in the direction away from the protrusion 22.

[0112] The pressure ring 60 may be provided with a second through hole 61. The second through hole 61 may penetrate the pressure ring 60 along its thickness direction (Z direction in the figure). The pressure ring 60 may surround the second sub-post 412 of the pole post 40. That is, the second sub-post 412 of the pole post 40 may be located within the second through hole 61.

[0113] The pressure ring 60 may be provided with a second limiting hole 62. The opening of the second limiting hole 62 may be located on the surface of the pressure ring 60 facing the upper plastic 20. The second limiting hole 62 may be formed by recessing from the surface of the pressure ring 60 facing the upper plastic 20 toward the interior of the pressure ring 60. The second limiting hole 62 may be located at the outer edge of the second through hole 61. The second limiting hole 62 is a blind hole. There may be multiple second limiting holes 62. The structures of the multiple second limiting holes 62 may be similar, identical, or different. The multiple second limiting holes 62 may be spaced apart on the surface of the pressure ring 60 facing the upper plastic 20. Furthermore, the multiple second limiting holes 62 may also be spaced apart along the circumferential direction of the second through hole 61.

[0114] For example, the number of second limiting holes 62 can be twelve. Of the twelve second limiting holes 62, six second limiting holes 62 can be spaced apart on the surface of one of the pressure rings 60 facing one of the upper plastic 20, and sequentially arranged along the circumferential direction of one second through hole 61. The remaining six second limiting holes 62 can be spaced apart on the surface of another pressure ring 60 facing another upper plastic 20, and sequentially arranged along the circumferential direction of another second through hole 61.

[0115] A limiting body 70 can be inserted into the upper plastic 20. One end of the limiting body 70 is located within the first limiting hole 13 of the top cover 10, and the other end of the limiting body 70 is located within the second limiting hole 62 of the top cover 10. The limiting body 70 can be used to support the pressure ring 60 and restrict the circumferential rotation of the pressure ring 60 relative to the upper plastic 20. For example, the number of limiting bodies 70 can be twelve. Of the twelve limiting bodies 70, six limiting bodies 70 can be inserted into one of the upper plastic 20 and spaced apart between the top cover 10 and one of the pressure rings 60, and the remaining six limiting bodies 70 can be inserted into another upper plastic 20 and spaced apart between the top cover 10 and another pressure ring 60.

[0116] In the embodiments of this application, the sealing ring 50 can have good elastic deformation properties, which can undergo elastic deformation after being compressed and rebound after the pressure is removed. The sealing ring 50 can include a first state and a second state. When the sealing ring 50 is in the first state, the sealing ring 50 is separated from both the lower plastic 30 and the top cover 10. When the sealing ring 50 is in the second state, the sealing ring 50 is sleeved on the outside of the column 41 of the pole post 40 and is located within the second gap W2 between the first hole 11 of the top cover 10, the second hole 31 of the lower plastic 30, and the base 42 of the pole post 40. That is, when the sealing ring 50 is in the first state, the sealing ring 50 is in a natural state without pressure. When the sealing ring 50 is in the second state, the sealing ring 50 is in a compressed state under pressure. The following description will take the sealing ring 50 in the second state as an example, but it should be understood that it is not limited thereto.

[0117] Please see Figure 10 The sealing ring 50 can be sleeved on the outside of the post 41 of the pole post 40, and located within the second gap W2 between the first hole 11 of the top cover 10, the second hole 31 of the lower plastic 30, and the base 42 of the pole post 40. The sealing ring 50 and the lower plastic 30 located within the second gap W2 are interference-fitted in the thickness direction (Z direction in the figure) of the top cover assembly 100. For example, the interference amount between the sealing ring 50 and the lower plastic 30 located within the second gap W2 and the thickness direction of the top cover assembly 100 can be 0.1 mm.

[0118] Understandably, in related technologies, when the top cover assembly is assembled, the insulation resistance between the electrode post and the top cover can be greater than 200MΩ, ensuring good insulation performance between them. However, when the top cover assembly comes into contact with the electrolyte, the electrolyte can seep into the area where the electrode post is located. Due to manufacturing tolerances and assembly tolerances of the components within the top cover assembly, a gap will form between the radial direction of the sealing ring and the inner wall of the electrode post hole in the lower plastic. The presence of electrolyte in this gap can drastically reduce the insulation performance between the top cover and the electrode post, thus lowering the safety of the electrode assembly. Furthermore, when there is an unsealed gap between the upper plastic and the sealing ring, foreign objects such as metal shavings or moisture can easily enter this gap, further reducing the insulation between the electrode post and the top cover.

[0119] Therefore, in the embodiments of this application, by positioning a portion of the sealing ring 50 within the second gap W2 between the lower plastic 30 and the base 42 of the electrode post 40 in the thickness direction of the top cover assembly 100, and by ensuring an interference fit between the sealing ring 50 within the second gap W2 and the lower plastic 30 in the thickness direction of the top cover assembly 100, the sealing ring 50 can effectively seal the second gap W2 between the lower plastic 30 and the top cover 10, blocking the flow path of electrolyte into the electrode post 40 and the top cover 10 through the second gap W2. This avoids the problem of short circuit caused by the electrode post 40 and the top cover 10 becoming conductive due to contact with electrolyte, thereby improving the safety performance of the electrode assembly 220.

[0120] Furthermore, the thinning groove 33 of the lower plastic 30 can form a partial second gap W2, and the sealing ring 50 located in the thinning groove 33 is interference-fitted with the lower plastic 30.

[0121] Understandably, if the lower plastic 30 does not have a thinning groove 33, the sealing ring 50 located within the second gap W2 will be relatively thin after the lower plastic 30 and the sealing ring 50 are assembled. This would reduce the sealing effect between the lower plastic 30 and the electrode post 40 and increase the manufacturing difficulty of the sealing ring 50. Furthermore, since the thickness of the lower plastic 30 at the location of the thinning groove 33 is relatively thin, placing part of the sealing ring 50 within the thinning groove 33 provides a certain amount of space for filling and deformation of the sealing ring 50, preventing excessive rebound force of the sealing ring 50 from reducing the sealing effect between the lower plastic 30 and the electrode post 40. Moreover, after being compressed, the sealing ring 50 can extend radially to fully contact the lower plastic 30, thereby extending the sealing surface between the lower plastic 30 and the sealing ring 50 and improving the sealing performance between the lower plastic 30 and the electrode post 40.

[0122] Furthermore, in the longitudinal direction (X direction in the diagram) of the top cover assembly 100, the overlap length between the sealing ring 50 and the lower plastic 30 can be greater than or equal to 0.2 mm. This allows for sufficient contact area between the sealing ring 50 and the lower plastic 30, thereby effectively extending the sealing surface between them.

[0123] Please continue reading. Figure 10The sealing ring 50 can contact the inner wall of the first hole 11 of the top cover 10, the inner wall of the second hole 31 of the lower plastic 30, the bottom wall of the thinning groove 33, and part of the second surface 102 of the top cover 10. The sealing ring 50 located in the first hole 11 of the top cover 10 is interference-fitted with the top cover 10 in the radial direction of the sealing ring 50. The sealing ring 50 located in the second hole 31 of the lower plastic 30 is interference-fitted with the lower plastic 30 in the radial direction of the sealing ring 50. It can be understood that, based on the primary seal formed between the bottom of the sealing ring 50 and the lower plastic 30, the secondary seal formed between the top of the sealing ring 50 and the top cover 10 can enhance the sealing performance of the sealing ring 50 and further prevent electrolyte in the electrode assembly 220 or moisture outside the battery 200 from entering the gap between the top cover 10 and the terminal post 40, thus preventing the top cover 10 and the terminal post 40 from becoming conductive.

[0124] In the embodiments of this application, the sealing ring 50 located in the first hole 11 of the top cover 10 can contact the end of the protrusion 22 away from the upper plastic body 21. Specifically, the sealing ring 50 located in the first hole 11 of the top cover 10 can contact a combination of one or more of the following: the bottom surface 224 of the protrusion 22, the first transition arc surface 223 of the protrusion 22, the guide slope 221 of the protrusion 22, and the second transition arc surface 225 of the protrusion 22.

[0125] Understandably, by making the sealing ring 50 contact with the upper plastic 20, the sealing ring 50 and the upper plastic 20 can cooperate to isolate the top cover 10 and the pole post 40, so that the top cover 10 and the pole post 40 have good insulation performance, effectively avoiding the problem of short circuit caused by electrical conduction between the top cover 10 and the pole post 40, and the reliability is better.

[0126] Furthermore, the sealing ring 50 located in the first hole 11 of the top cover 10 can be interference-fitted with the end of the protrusion 22 away from the upper plastic body 21. The interference amount (i.e., interference distance) between the sealing ring 50 and the upper plastic 20 in the thickness direction of the top cover assembly 100 can be in the range of 0.1mm-0.3mm (including the endpoint values ​​of 0.1mm and 0.3mm).

[0127] The sealing ring 50 located in the first hole 11 of the top cover 10 can also be located in the first gap W1 between the guide slope 221 of the upper plastic 20 and the inner wall of the first hole 11 of the top cover 10, and cover part of the guide slope 221, or cover the guide slope 221 and at least part of the second transition arc surface 225. It is understood that by placing part of the sealing ring 50 in the first gap W1 and covering the guide slope 221, or covering the guide slope 221 and at least part of the second transition arc surface 225, the sealing ring 50 can surround the bottom of the lower plastic 30 (i.e., the end of the protrusion 22 away from the upper plastic body 21), increasing the upward compression space of the sealing ring 50 and the sealing height of the sealing ring 50, so that the sealing ring 50 can surround the bottom of the upper plastic 20 with a larger area, preventing metal shavings from moving between the top cover 10 and the pole post 40, and improving the insulation performance between the top cover 10 and the pole post 40.

[0128] Please refer to the following: Figure 10 and Figure 16 , Figure 16 yes Figure 3 A schematic diagram of the structure of the sealing ring 50 of the top cover assembly 100 at one angle.

[0129] The sealing ring 50 may include a first sub-part 51 and a second sub-part 52. The first sub-part 51 may be sleeved on the outside of the post 41 of the pole post 40. The second sub-part 52 may be connected around the periphery of the first sub-part 51 and coaxially arranged with the first sub-part 51. The thickness of the second sub-part 52 (i.e., the dimension of the second sub-part 52 along the Z direction) is smaller than the thickness of the first sub-part 51 (i.e., the dimension of the first sub-part 51 along the Z direction), thereby forming a stepped surface at the connection between the second sub-part 52 and the first sub-part 51. When the sealing ring 50 is in the first state, the first sub-part 51 can be separated from the pole post 40, the lower plastic 30, and the top cover 10, and the second sub-part 52 can be separated from the pole post 40, the lower plastic 30, and the top cover 10. When the sealing ring 50 is in the second state, the first sub-part 51 can be located within the first hole 11 of the top cover 10, the second hole 31 of the lower plastic 30, and the first gap W1, and the second sub-part 52 can be located within the second hole 31 and the second gap W2 of the lower plastic 30. The second sub-part 52 located in the second gap W2 can be interference-fitted with the top cover 10 in the thickness direction of the top cover assembly 100.

[0130] It is understandable that by including a first sub-part 51 and a second sub-part 52 of different thicknesses in the sealing ring 50, the sealing ring 50 can be rapidly and fully deformed between the lower plastic 30 and the pole post 40, and between the top cover 10 and the pole post 40, during the assembly of the top cover assembly 100. This fills the spaces of different sizes between the lower plastic 30 and the pole post 40, and between the top cover 10 and the pole post 40, thereby improving the assembly efficiency and sealing performance of the top cover assembly 100.

[0131] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A top cover assembly, characterized in that, The top cover assembly includes; A top cover, comprising a first surface and a second surface, the first surface and the second surface being disposed opposite to each other in the thickness direction of the top cover, the top cover having a first hole and a first mounting groove, the first hole penetrating through the first surface and the second surface, the opening of the first mounting groove being located on the first surface, and the first mounting groove being coaxially disposed with and connected to the first hole; A terminal post, wherein the terminal post passes through the first hole; An upper plastic body, comprising a connected upper plastic body and a protrusion, both the upper plastic body and the protrusion being sleeved on the outside of the pole post. The upper plastic body is installed in the first mounting groove, and the protrusion is installed in the first hole. The outer surface of the protrusion includes a guide slope, a first transition arc surface, and a bottom surface. The bottom surface is the end face of the protrusion away from the upper plastic body. In the direction from the upper plastic body toward the protrusion, the distance between the guide slope and the hole wall of the first hole gradually increases. The first transition arc surface bends and connects the guide slope and the bottom surface. A sealing ring is fitted on the outside of the pole post. Part of the sealing ring is located inside the first hole and is interference-fitted with the end of the protrusion away from the upper plastic body. The sealing ring located inside the first hole is also in contact with the bottom surface and the first transition arc surface.

2. The top cover assembly as claimed in claim 1, characterized in that, A first gap is formed between the guide bevel and the inner wall of the first hole, and part of the sealing ring is located within the first gap and covers at least part of the guide bevel.

3. The top cover assembly as claimed in claim 1, characterized in that, The outer surface of the protrusion also includes an outer side surface and a second transition arc surface. The outer side surface is disposed opposite to the inner wall of the first hole, and the second transition arc surface is bent and connected between the outer side surface and the guide slope.

4. The top cover assembly as claimed in claim 1, characterized in that, The upper plastic is provided with a first through hole, which penetrates the upper plastic body and the protrusion along the thickness direction of the upper plastic, and the pole post is disposed in the first through hole; The outer surface of the protrusion also includes a third transition arc surface, which is bent and connected between the bottom surface and the inner wall of the first through hole. The third transition arc surface also contacts the sealing ring located in the first hole.

5. The top cover assembly as claimed in claim 1, characterized in that, A fourth transition arc surface connects the bottom wall of the first mounting groove and the inner wall of the first hole. The connection between the upper plastic body and the protrusion is opposite to the fourth transition arc surface.

6. The top cover assembly as described in any one of claims 1-5, characterized in that, The interference fit between the sealing ring and the upper plastic in the thickness direction of the top cover assembly is in the range of 0.1mm-0.3mm.

7. The top cover assembly as claimed in claim 2, characterized in that, The top cover assembly also includes a lower plastic layer, which is stacked with the top cover. The lower plastic layer has a second hole that penetrates the lower plastic layer along its thickness direction and communicates with the first hole. The pole includes a column and a base. The column passes through the first hole, the second hole and the upper plastic. The base is coaxially arranged with and connected to the column. The base is located on the side of the lower plastic facing away from the top cover and forms a second gap with the lower plastic. The sealing ring is fitted onto the column and located within the first hole, the second hole, the first gap, and the second gap. The sealing ring located within the second gap is interference-fitted with the lower plastic in the thickness direction of the top cover assembly.

8. The top cover assembly as claimed in claim 7, characterized in that, The lower plastic is provided with a thinning groove, the opening of the thinning groove is located on the surface of the lower plastic away from the top cover, the thinning groove is coaxially arranged and connected with the second hole, and the thinning groove forms part of the second gap.

9. The top cover assembly as claimed in claim 8, characterized in that, The distance between the bottom wall of the thinning groove and the surface of the lower plastic facing the top cover is in the range of 0.1mm-0.7mm.

10. The top cover assembly as claimed in claim 8, characterized in that, The sealing ring is in contact with the inner wall of the first hole, the inner wall of the second hole, the bottom wall of the thinning groove, and the part of the top cover facing the lower plastic. The sealing ring located in the first hole is interference-fitted with the top cover in the radial direction of the sealing ring, and the sealing ring located in the second hole is interference-fitted with the lower plastic in the radial direction of the sealing ring.

11. The top cover assembly as claimed in any one of claims 8-10, characterized in that, Along the length of the top cover assembly, the overlap length between the sealing ring and the lower plastic is greater than or equal to 0.2 mm.

12. A battery, characterized in that, The battery includes an electrode assembly, a housing, and a top cover assembly as described in any one of claims 1-11, the top cover assembly being connected to the housing and forming a receiving space with the housing, the electrode assembly being located within the receiving space.

13. An electrical appliance, characterized in that, The electrical device includes the battery as described in claim 12.

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