Top cover assembly, battery and electric device

Abstract

The application provides a top cover assembly, a battery and an electric device. The top cover assembly comprises a top cover, a lower plastic, a pole and a sealing ring. The top cover comprises a first surface and a first through hole. The first surface faces the electric core. The first through hole penetrates the top cover along the thickness direction of the top cover. The lower plastic is provided with a second through hole. The second through hole penetrates the lower plastic along the thickness direction of the lower plastic. The second through hole is communicated with the first through hole. The pole comprises a pole base and a pole body. The pole base is connected to the surface of the lower plastic away from the top cover. One end of the pole body is connected to the pole base. The other end of the pole body is protrudingly arranged relative to the top cover. The pole body penetrates the first through hole and the second through hole. The sealing ring is sleeved on the pole body. Part of the sealing ring is located in the second through hole and elastically abuts between the top cover and the pole base. The sealing ring located in the second through hole is in interference connection with the lower plastic. The technical scheme of the application can prevent the electrolyte in the electric core from penetrating into the inside of the top cover assembly, thereby avoiding the decrease of the resistance of the pole.

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, the market demand for batteries with recyclable characteristics is increasing. A battery consists of a cell, a top cover assembly, and a casing. The cell is located within the space enclosed by the top cover assembly and the casing. However, there are certain leakage paths within the top cover assembly. This means that after electrolyte is injected into the cell, actions such as inverting or flipping the battery can cause electrolyte to seep into these leakage paths within the top cover assembly. The large number of ions present in the electrolyte acts as conductors, electrically connecting the terminals of the top cover assembly to the top cover itself, resulting in a decrease in the resistance of the terminals. Summary of the Invention

[0003] Embodiments of this application provide a top cover assembly, a battery, and an electrical device that can prevent electrolyte in the battery cell from seeping into the top cover assembly, thereby avoiding a decrease in the resistance of the terminals.

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

[0005] A top cover, the top cover including a first surface for facing the battery cell, the top cover having a first through hole extending through the top cover along the thickness direction;

[0006] The lower plastic is connected to the first surface. The lower plastic is provided with a second through hole, which penetrates the lower plastic along the thickness direction and communicates with the first through hole.

[0007] An electrode post, comprising an electrode post base and an electrode post body, wherein the electrode post base is connected to the surface of the lower plastic layer facing away from the top cover, one end of the electrode post body is connected to the electrode post base, the electrode post body passes through the first through hole and the second through hole, and the other end of the electrode post body protrudes relative to the top cover; and

[0008] A sealing ring is fitted onto the pole body, with a portion of the sealing ring located within the second through hole and elastically abutting between the top cover and the pole base. The end of the sealing ring located within the second through hole, near the lower plastic, is interference-fitted with the lower plastic.

[0009] It is understandable that, due to considerations of battery thermal expansion and assembly tolerances, there are generally certain gaps in the top cover assembly, such as between the terminals and the lower plastic, and between the sealing ring and the lower plastic. However, after the electrolyte is injected into the cell, subsequent production, assembly, and transportation processes may involve inverting and flipping the battery, causing the electrolyte to seep into the seepage paths formed by the gaps in the top cover assembly. The large number of ions present in the electrolyte will act as conductors, electrically connecting the terminals of the top cover assembly to the top cover, resulting in a decrease in the resistance of the terminals.

[0010] Therefore, in the technical solution of this application, by making the sealing ring and the lower plastic interference fit, the gap between the sealing ring and the lower plastic can be eliminated, thereby blocking the electrolyte that has penetrated into the gap inside the top cover assembly at the interference fit between the lower plastic and the sealing ring, preventing the electrolyte from entering the gap between the top cover and the electrode post, thus preventing the top cover and the electrode post from conducting electricity, which would lead to the problem of the electrode post resistance decreasing.

[0011] For example, the outer diameter of the sealing ring can be increased or the inner diameter of the lower plastic can be decreased, so that the outer diameter of the sealing ring is larger than the inner diameter of the lower plastic, thereby achieving an interference fit between the sealing ring and the lower plastic.

[0012] In one possible implementation, the sealing ring includes an outer side and a bottom surface. The outer side is the surface of the sealing ring near the lower plastic end. The outer side is interference-fitted with the inner wall of the second through hole. The bottom surface abuts against the pole base. The outer side is perpendicular to the bottom surface.

[0013] In one possible implementation, the sealing ring includes an outer side surface, which is the surface of the sealing ring near the lower plastic end. The outer side surface is interference-fitted with the inner wall of the second through hole. The outer side surface includes a first connecting surface and a second connecting surface connected to each other. The first connecting surface is closer to the top cover than the second connecting surface. Both the first connecting surface and the second connecting surface are inclined relative to the thickness direction of the sealing ring.

[0014] The inner wall of the second through hole includes a first contact surface and a second contact surface connected to each other. The first contact surface is closer to the top cover than the second contact surface. Both the first contact surface and the second contact surface are inclined relative to the thickness direction of the lower plastic.

[0015] The first contact surface is interference-fitted with at least a portion of the first connecting surface, and / or the second contact surface is interference-fitted with at least a portion of the second connecting surface.

[0016] In one possible implementation, the sealing ring further includes a top surface and a bottom surface, which are disposed opposite to each other in the thickness direction of the sealing ring and are respectively connected to both ends of the outer side surface of the sealing ring. The top surface abuts against the top cover, and the bottom surface abuts against the pole base. The cross-sectional width of the first connecting surface in the thickness direction of the sealing ring gradually increases from the top surface to the bottom surface, and the cross-sectional width of the second connecting surface in the thickness direction of the sealing ring gradually decreases from the top surface to the bottom surface.

[0017] The lower plastic includes a third surface and a fourth surface. The third surface and the fourth surface are arranged opposite to each other in the thickness direction of the lower plastic and are respectively connected to both ends of the inner wall of the second through hole. The fourth surface abuts against the top cover. The cross-sectional width of the first contact surface in the thickness direction of the lower plastic gradually increases from the fourth surface to the third surface, and the cross-sectional width of the second contact surface in the thickness direction of the lower plastic gradually decreases from the fourth surface to the third surface.

[0018] In one possible implementation, the sealing ring further includes a top surface and a bottom surface, which are disposed opposite to each other in the thickness direction of the sealing ring and are respectively connected to both ends of the outer side surface of the sealing ring. The top surface abuts against the top cover, and the bottom surface abuts against the pole base. The cross-sectional width of the first connecting surface in the thickness direction of the sealing ring gradually decreases from the top surface to the bottom surface, and the cross-sectional width of the second connecting surface in the thickness direction of the sealing ring gradually increases from the top surface to the bottom surface.

[0019] The lower plastic includes a third surface and a fourth surface. The third surface and the fourth surface are arranged opposite to each other in the thickness direction of the lower plastic and are respectively connected to both ends of the inner wall of the second through hole. The fourth surface abuts against the top cover. The cross-sectional width of the first contact surface in the thickness direction of the lower plastic gradually decreases from the fourth surface to the third surface, and the cross-sectional width of the second contact surface in the thickness direction of the lower plastic gradually increases from the fourth surface to the third surface.

[0020] In one possible implementation, the sealing ring includes an outer side surface, which is the surface of the sealing ring near the lower plastic end. The outer side surface is interference-fitted with the inner wall of the second through hole. The outer side surface includes a first connecting surface and a second connecting surface connected to each other. The first connecting surface is closer to the top cover than the second connecting surface. The first connecting surface is parallel to the thickness direction of the sealing ring, and the second connecting surface is inclined relative to the thickness direction of the sealing ring.

[0021] The inner wall of the second through hole includes a first contact surface and a second contact surface connected to each other. The first contact surface is closer to the top cover than the second contact surface. The first contact surface is arranged parallel to the thickness direction of the lower plastic, and the second contact surface is arranged inclined relative to the thickness direction of the lower plastic.

[0022] The first contact surface is interference-fitted with at least a portion of the first connecting surface, and / or the second contact surface is interference-fitted with at least a portion of the second connecting surface.

[0023] In one possible implementation, the sealing ring further includes a top surface and a bottom surface, which are disposed opposite to each other in the thickness direction of the sealing ring and are respectively connected to both ends of the outer side surface of the sealing ring. The top surface abuts against the top cover, and the bottom surface abuts against the pole base. The cross-sectional width of the first connecting surface in the thickness direction of the sealing ring remains unchanged from the top surface to the bottom surface, and the cross-sectional width of the second connecting surface in the thickness direction of the sealing ring gradually decreases from the top surface to the bottom surface.

[0024] The lower plastic includes a third surface and a fourth surface. The third surface and the fourth surface are arranged opposite to each other in the thickness direction of the lower plastic and are respectively connected to both ends of the inner wall of the second through hole. The fourth surface abuts against the top cover. The cross-sectional width of the first contact surface in the thickness direction of the lower plastic remains unchanged from the fourth surface to the third surface. The cross-sectional width of the second contact surface in the thickness direction of the lower plastic gradually decreases from the fourth surface to the third surface.

[0025] In one possible implementation, the sealing ring further includes a top surface and a bottom surface, which are disposed opposite to each other in the thickness direction of the sealing ring and are respectively connected to both ends of the outer side surface of the sealing ring. The top surface abuts against the top cover, and the bottom surface abuts against the pole base. The cross-sectional width of the first connecting surface in the thickness direction of the sealing ring remains unchanged from the top surface to the bottom surface, and the cross-sectional width of the second connecting surface in the thickness direction of the sealing ring gradually increases from the top surface to the bottom surface.

[0026] The lower plastic includes a third surface and a fourth surface. The third surface and the fourth surface are arranged opposite to each other in the thickness direction of the lower plastic and are respectively connected to both ends of the inner wall of the second through hole. The fourth surface abuts against the top cover. The cross-sectional width of the first contact surface in the thickness direction of the lower plastic remains unchanged from the fourth surface to the third surface. The cross-sectional width of the second contact surface in the thickness direction of the lower plastic gradually increases from the fourth surface to the third surface.

[0027] In one possible implementation, the sealing ring includes an outer side surface, which is the surface of the sealing ring near the lower plastic end. The outer side surface is interference-fitted with the inner wall of the second through hole. The outer side surface includes a first connecting surface and a second connecting surface connected to each other. The first connecting surface is closer to the top cover than the second connecting surface. The first connecting surface is inclined relative to the thickness direction of the sealing ring, and the second connecting surface is parallel to the thickness direction of the sealing ring.

[0028] The inner wall of the second through hole includes a first contact surface and a second contact surface connected to each other. The first contact surface is closer to the top cover than the second contact surface. The first contact surface is inclined relative to the thickness direction of the lower plastic, and the second contact surface is parallel to the thickness direction of the lower plastic.

[0029] The first contact surface is interference-fitted with at least a portion of the first connecting surface, and / or the second contact surface is interference-fitted with at least a portion of the second connecting surface.

[0030] In one possible implementation, the sealing ring further includes a top surface and a bottom surface, which are disposed opposite to each other in the thickness direction of the sealing ring and are respectively connected to both ends of the outer side surface of the sealing ring. The top surface abuts against the top cover, and the bottom surface abuts against the pole base. The cross-sectional width of the first connecting surface in the thickness direction of the sealing ring gradually increases from the top surface to the bottom surface, and the cross-sectional width of the second connecting surface in the thickness direction of the sealing ring remains unchanged from the top surface to the bottom surface.

[0031] The lower plastic includes a third surface and a fourth surface. The third surface and the fourth surface are arranged opposite to each other in the thickness direction of the lower plastic and are respectively connected to both ends of the inner wall of the second through hole. The fourth surface abuts against the top cover. The cross-sectional width of the first contact surface in the thickness direction of the lower plastic gradually increases from the fourth surface to the third surface. The cross-sectional width of the second contact surface in the thickness direction of the lower plastic remains unchanged from the fourth surface to the third surface.

[0032] In one possible implementation, the sealing ring further includes a top surface and a bottom surface, which are disposed opposite to each other in the thickness direction of the sealing ring and are respectively connected to both ends of the outer side surface of the sealing ring. The top surface abuts against the top cover, and the bottom surface abuts against the pole base. The cross-sectional width of the first connecting surface in the thickness direction of the sealing ring gradually decreases from the top surface to the bottom surface, and the cross-sectional width of the second connecting surface in the thickness direction of the sealing ring remains unchanged from the top surface to the bottom surface.

[0033] The lower plastic includes a third surface and a fourth surface. The third surface and the fourth surface are arranged opposite to each other in the thickness direction of the lower plastic and are respectively connected to both ends of the inner wall of the second through hole. The fourth surface abuts against the top cover. The cross-sectional width of the first contact surface in the thickness direction of the lower plastic gradually decreases from the fourth surface to the third surface. The cross-sectional width of the second contact surface in the thickness direction of the lower plastic remains unchanged from the fourth surface to the third surface.

[0034] In one possible implementation, the angle formed by the connection of the first connecting surface and the second connecting surface is the first angle, and the angle formed by the connection of the first contact surface and the second contact surface is the second angle, wherein the second angle is smaller than the first angle.

[0035] In one possible implementation, the sealing ring includes a first state and a second state;

[0036] When the sealing ring is in the first state, the sealing ring is separated from the lower plastic, and the cross-sectional width of the sealing ring along the thickness direction of the sealing ring is the first width;

[0037] When the sealing ring is in the second state, the sealing ring is interference-fitted with the lower plastic, and the cross-sectional width of the sealing ring along the thickness direction is the second width, which is smaller than the first width.

[0038] In one possible implementation, the difference between the first width and the second width is in the range of 3% to 5% of the first width.

[0039] In one possible implementation, the sealing ring includes a sealing ring body and a connecting portion. The sealing ring body is sleeved on the electrode body and spaced apart from the electrode body, and is interference-fitted with the lower plastic. One end of the connecting portion is connected to the side of the sealing ring body away from the lower plastic, and the other end of the connecting portion abuts against the electrode body.

[0040] In one possible implementation, the top cover is provided with a first mounting groove, the opening of the first mounting groove is located on the first surface, and the first mounting groove is coaxially arranged and connected with the first through hole.

[0041] The lower plastic includes a lower plastic body and a first protrusion. The lower plastic body is connected to the first surface. The first protrusion is fixedly connected to the surface of the lower plastic body facing the top cover and is located in the first mounting groove. The lower plastic also has a second mounting groove. The opening of the second mounting groove is located on the surface of the lower plastic body away from the top cover. The second mounting groove is coaxially arranged and connected with the second through hole. Part of the pole post base is located in the second mounting groove.

[0042] Secondly, this application also provides a battery, the battery including a cell, a housing and a top cover assembly as described above, the top cover assembly being connected to the housing and forming an accommodating space with the housing, the cell being located within the accommodating space.

[0043] Thirdly, this application also provides an electrical device, which includes the battery described above. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the energy storage system provided in an embodiment of this application;

[0045] Figure 2 This is a schematic diagram of a battery structure provided in an embodiment of this application;

[0046] Figure 3 This is a schematic diagram of the structure of the top cover assembly provided in an embodiment of this application;

[0047] Figure 4 yes Figure 3 The exploded view of the top cover assembly is shown.

[0048] Figure 5 It is along Figure 3 The diagram shows a first cross-sectional view of a portion of the top cover assembly obtained by cutting along section line AA.

[0049] Figure 6a yes Figure 3 A schematic diagram of the top cover assembly at one angle;

[0050] Figure 6b yes Figure 3 A schematic diagram of the top cover assembly from another angle;

[0051] Figure 7a yes Figure 3 A schematic diagram of an angle of the lower plastic structure of the top cover assembly shown;

[0052] Figure 7b yes Figure 7a The diagram shows a structural schematic of the lower plastic at another angle;

[0053] Figure 8 yes Figure 7a The diagram shows a structural schematic of the lower plastic at another angle;

[0054] Figure 9 It is along Figure 8 A schematic cross-sectional view of the lower plastic portion structure obtained by cutting along section line BB;

[0055] Figure 10a yes Figure 3 A schematic diagram of one angle of the sealing ring structure of the top cover assembly shown;

[0056] Figure 10b yes Figure 10a A schematic diagram of the sealing ring from another angle is shown;

[0057] Figure 11a yes Figure 3 A schematic diagram of the structure of the upper plastic part of the top cover assembly at one angle;

[0058] Figure 11b yes Figure 3 A schematic diagram of the upper plastic of the top cover assembly from another angle;

[0059] Figure 12 It is along Figure 11a The diagram shows a cross-sectional view of the upper plastic obtained by cutting along the cutting line CC.

[0060] Figure 13a yes Figure 3 The diagram shows a structural schematic of one type of pole of the top cover assembly in one state;

[0061] Figure 13b yes Figure 13a The diagram shows the structure of the pole in another state;

[0062] Figure 14 yes Figure 3 Another structural schematic diagram of the pole of the top cover assembly shown;

[0063] Figure 15a It is along Figure 3 A second cross-sectional view of a portion of the top cover assembly obtained by cutting along section line AA;

[0064] Figure 15b yes Figure 15a A magnified view of the central region L;

[0065] Figure 16 yes Figure 3 A schematic diagram of an angle of another structure of the sealing ring of the top cover assembly shown;

[0066] Figure 17 yes Figure 3 A schematic diagram of an angle of another structure of the lower plastic of the top cover assembly shown;

[0067] Figure 18 It is along Figure 17 Another cross-sectional view of the lower plastic portion structure obtained by cutting along the cutting line DD shown;

[0068] Figure 19a It is along Figure 3 A third cross-sectional view of a portion of the top cover assembly obtained by cutting along section line AA.

[0069] Figure 19b yes Figure 19a A magnified view of region M in the middle;

[0070] Figure 20a It is along Figure 3 The diagram shows a fourth cross-sectional view of a portion of the top cover assembly obtained by cutting along section line AA.

[0071] Figure 20b yes Figure 20a A magnified view of region N in the middle;

[0072] Figure 21a It is along Figure 3 The fifth cross-sectional view of a portion of the top cover assembly obtained by cutting along section line AA is shown.

[0073] Figure 21b yes Figure 21a A magnified view of region O in the middle;

[0074] Figure 22a It is along Figure 3 The sixth cross-sectional view of a portion of the top cover assembly obtained by cutting along section line AA is shown.

[0075] Figure 22b yes Figure 22a A magnified view of region P in the middle;

[0076] Figure 23a It is along Figure 3 The diagram shows a seventh cross-sectional view of a portion of the top cover assembly obtained by cutting along section line AA.

[0077] Figure 23b yes Figure 23a A magnified view of region Q in the middle.

[0078] Figure label:

[0079] Energy storage system 400, power conversion device 410, first user load 420, second user load 430, electrical equipment 300, battery 200, housing 210, battery cell 220, top cover assembly 100, top cover 10, lower plastic 20, sealing ring 30, upper plastic 40, terminal post 50, explosion-proof valve 60, explosion-proof valve protection plate 70, first mounting groove 11, first through hole 12, top cover body 13, second protrusion 14, explosion-proof hole 15, first liquid injection hole 16, first surface 131, second surface 132, positioning groove 133, second through hole 21, second mounting groove 22, lower plastic body 23, first protrusion 24, positioning part 25, second liquid injection hole 26, third surface 231, fourth surface 232, outer surface 31, bottom surface 32. Sealing ring body; 33. Connecting part; 34. Inner side surface; 35. Top surface; 36. Third through hole; 41. Upper plastic body; 42. Third protrusion; 43. Fourth protrusion; 44. Third mounting groove; 45. Mark; 46. First hole; 411. Second hole; 412. Protruding structure a; Recessed structure b; Fifth surface 421; Sixth surface 422; End post body; 51. End post base; 52. First body 511; Second body 512; Third body 513; First sub-part 513a; Second sub-part 513b; First connecting surface 311; Second connecting surface 312; First transition surface 313; First contact surface 211; Second contact surface 212; Second transition surface 213; First included angle A1; Second included angle A2; First width W1; Second width W2. Detailed Implementation

[0080] For ease of understanding, the terminology used in the embodiments of this application will be explained first.

[0081] 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.

[0082] Multiple: refers to two or more.

[0083] 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.

[0084] The specific embodiments of this application will now be clearly described in conjunction with the accompanying drawings. Obviously, the described embodiments are merely a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0085] Embodiments of this application provide a top cover assembly, a battery, and an electrical device.

[0086] 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.

[0087] Taking electrochemical energy storage as an example, the embodiments of this application provide an electrical device 300, which is equipped with a set of chemical batteries. The main purpose is to use 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, the electrical energy generated by wind and solar energy is stored in the chemical batteries. When the use of external electrical energy reaches its peak, the stored electricity is released for use, or it is transferred to places where electricity is scarce for use.

[0088] 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 (number 300) include:

[0089] 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.

[0090] Small and medium-sized energy storage cabinets used in industrial and commercial energy storage scenarios on the user side, and small household energy storage boxes used in residential 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 cabinet / box during off-peak hours to reduce costs, and then release the electricity from the device during peak hours 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 energy storage devices 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.

[0091] 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.

[0092] 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.

[0093] 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, the multiple batteries 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 are arranged at intervals. The multiple batteries can be connected in series, in parallel, or 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, but it should be understood that the electrical device 300 is not limited thereto.

[0094] Please see Figure 2 , Figure 2 This is a schematic diagram of a battery 200 provided in an embodiment of this application.

[0095] 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.

[0096] Battery 200 may include a top cover assembly 100, a housing 210, and a battery cell 220. The top cover assembly 100 is connected to the housing 210 and forms a receiving space with the housing 210, within which the battery cell 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 or a prismatic battery, etc.

[0097] 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 battery cell 220, and is not to specifically limit the connection positions, specific structures, or quantities of each device. 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.

[0098] With the development of green energy, the market demand for recyclable batteries is increasing. In a battery, the cell is located in the space enclosed by the top cover assembly and the outer casing. The top cover assembly includes structures such as terminals, a top cover, upper plastic, lower plastic, and a sealing ring. Understandably, the battery generates heat during charging and discharging, causing thermal expansion and deformation of the plastic materials in the top cover assembly (such as the sealing ring and lower plastic). To avoid deformation or excessive pressure caused by thermal expansion, certain gaps are left in the top cover assembly, for example, between the terminals and the lower plastic, and between the sealing ring and the lower plastic, to allow the components in the top cover assembly to expand and contract freely. However, after the electrolyte is injected into the cell, subsequent production processes may involve inverting and flipping the battery, causing the electrolyte to seep into the seepage paths formed by the gaps in the top cover assembly. The large number of ions present in the electrolyte will act as conductors, electrically connecting the terminals of the top cover assembly to the top cover, resulting in a decrease in the resistance of the terminals. For example, after the top cover assembly is immersed in the electrolyte, the resistance of the terminal block decreases from more than 55 GΩ before immersion to 0.001 MΩ after immersion.

[0099] Therefore, embodiments of this application provide a top cover assembly 100 that prevents electrolyte in the battery cell 220 from seeping into the top cover assembly 100, thereby avoiding a decrease in the resistance of the terminal 50. The structure of the top cover assembly 100 will be described in detail below through seven specific embodiments.

[0100] First embodiment:

[0101] 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.

[0102] The top cover assembly 100 may include a top cover 10, a lower plastic 20, a sealing ring 30, an upper plastic 40, a terminal post 50, an explosion-proof valve 60, and an explosion-proof valve protection plate 70. The lower plastic 20 and the upper plastic 40 are respectively connected to two opposite surfaces of the top cover 10 in the thickness direction (Z direction in the diagram). The terminal post 50 is mounted on the upper plastic 40, the top cover 10, and the lower plastic 20, and can serve as an electrode lead-out of the battery 200. The sealing ring 30 is sleeved on the outside of the terminal post 50 and abuts against the surface of the top cover 10 opposite to the upper plastic 40. The explosion-proof valve 60 and the explosion-proof valve protection plate 70 are both connected to the explosion-proof hole 15 on the top cover 10 and are sequentially arranged in the thickness direction of the top cover 10 to achieve pressure relief protection for the battery 200. The explosion-proof valve protection plate 70 covers the explosion-proof valve 60.

[0103] In this embodiment, there can be two terminals 50, one positive and one negative. The two terminals 50 are spaced apart along the length of the top cover assembly 100 (X direction in the diagram). There can also be two upper plastic rings 40. One upper plastic ring 40 is fitted onto the positive terminal, and the other upper plastic ring 40 is fitted onto the negative terminal. There can also be two sealing rings 30. One sealing ring 30 is fitted onto the positive terminal, and the other sealing ring 30 is fitted onto the negative terminal.

[0104] The following description will use the assembly of one terminal post 50, one upper plastic 40, one sealing ring 30 with the top cover 10 and the lower plastic 20 as an example to illustrate the structure of the top cover assembly 100. Unless otherwise specified, the description of one terminal post 50, one upper plastic 40, and one sealing ring 30 can be applied to other terminal posts 50, upper plastic 40, and sealing rings 30.

[0105] Please refer to the following: Figure 5 , Figure 6a and Figure 6b , Figure 5 It is along Figure 3 The diagram shows a first cross-sectional view of a portion of the structure of the top cover assembly 100 obtained by cutting along section line AA. Figure 6a yes Figure 3 The diagram shows a structural schematic of the top cover 10 of the top cover assembly 100 at one angle. Figure 6b yes Figure 3 A structural schematic diagram of the top cover 10 of the top cover assembly 100 from another angle.

[0106] The top cover 10 extends along the X direction and is provided with a first mounting groove 11 and a first through hole 12. The opening of the first mounting groove 11 is located on the surface of the top cover 10 opposite to the upper plastic 40. The first mounting groove 11 can be recessed into the top cover 10 from the surface opposite to the upper plastic 40. The first mounting groove 11 can be used to install the first protrusion 24 of the lower plastic 20 and the sealing ring 30. The first through hole 12 can penetrate the top cover 10 along the thickness direction. The first through hole 12 is coaxially arranged with and connected to the first mounting groove 11. The first through hole 12 can be located between the third through hole 41 of the upper plastic 40 and the second through hole 21 of the lower plastic 20, and connects the third through hole 41 of the upper plastic 40 and the second through hole 21 of the lower plastic 20. The first through hole 12 is used for the pole post 50 to pass through.

[0107] The top cover 10 may have two first mounting slots 11, spaced apart along its length (X direction in the diagram). Each first mounting slot 11 can be used to mount a first protrusion 24 of the lower plastic 20. The top cover 10 may also have two first through holes 12, spaced apart along its length and coaxially connected to the two first mounting slots 11. One first through hole 12 is used for the positive terminal to pass through, and the other is used for the negative terminal to pass through.

[0108] In this embodiment, the top cover 10 may include a top cover body 13 and a second protrusion 14. The second protrusion 14 is fixedly connected to the top cover body 13 and protrudes in the direction away from the battery cell 220. The second protrusion 14 and the top cover body 13 can be connected to form an integral structure. Exemplarily, the second protrusion 14 and the top cover body 13 can be an integral structure formed by connecting them through methods such as integral molding. Alternatively, the second protrusion 14 and the top cover body 13 can also be an integral structure formed by connecting them through assembly methods such as welding or bonding. It should be noted that the integral structures described below can all be formed by connecting them through assembly methods such as integral molding, welding, or bonding, and will not be described again.

[0109] The top cover body 13 may include a first surface 131 and a second surface 132. The first surface 131 and the second surface 132 are disposed opposite to each other in the thickness direction of the top cover 10. The first surface 131 faces the battery cell 220. The second surface 132 is away from the battery cell 220. The top cover body 13 may be provided with the first mounting groove 11 and the first through hole 12 described above. The opening of the first mounting groove 11 is located on the first surface 131. The first mounting groove 11 may be recessed from the first surface 131 into the interior of the top cover 10. The first through hole 12 may penetrate the first surface 131 and the second surface 132. That is, the first through hole 12 may penetrate the top cover body 13 along the thickness direction (Z direction in the figure).

[0110] The top cover body 13 may also be provided with a positioning groove 133. The opening of the positioning groove 133 is located on the first surface 131. The positioning groove 133 may be recessed from the first surface 131 into the interior of the top cover 10. The positioning groove 133 and the first mounting groove 11 are spaced apart in the width direction (Y direction in the figure) of the top cover body 13. The cross-sectional width of the positioning groove 133 along the thickness direction of the top cover 10 is smaller than the cross-sectional width of the first mounting groove 11 along the thickness direction of the top cover 10. The positioning groove 133 can be used to connect with the positioning part 25 of the lower plastic 20.

[0111] The top cover 10 can have one or more positioning grooves 133. When there are multiple positioning grooves 133, each positioning groove 133 is connected to a positioning part 25 of the lower plastic 20. Multiple positioning grooves 133 can be spaced apart in the width direction of the top cover body 13. In other embodiments, multiple positioning grooves 133 can also be spaced apart in the length direction (X direction in the figure) of the top cover body 13. Alternatively, multiple positioning grooves 133 can be spaced apart along the circumferential direction of the first mounting groove 11. The circumferential direction of the first mounting groove 11 is the direction surrounding the central axis of the first mounting groove 11. The embodiments of this application do not strictly limit the spacing direction of the multiple positioning grooves 133, only requiring that each positioning groove 133 is connected to each positioning part 25.

[0112] For example, there can be two positioning slots 133. In the width direction of the top cover 10, two positioning slots 133 are respectively disposed on both sides of the first mounting slot 11, and are spaced apart from the first mounting slot 11. The distance between one positioning slot 133 and the first mounting slot 11 can be equal to the distance between the other positioning slot 133 and the first mounting slot 11.

[0113] The second protrusion 14 is fixedly connected to the second surface 132 of the top cover body 13. The second protrusion 14 is disposed around the outer edge of the first through hole 12, and is coaxial with and spaced apart from the first through hole 12. That is, the second protrusion 14 is annular and surrounds the first through hole 12. The second protrusion 14 can be installed in the third mounting groove 45 of the upper plastic 40. The cross-sectional width of the second protrusion 14 along the thickness direction of the top cover 10 gradually increases from the top cover 10 to the lower plastic 20. In other embodiments, the cross-sectional width of the second protrusion 14 along the thickness direction (Z direction in the figure) of the top cover assembly 100 can also remain unchanged. Or the cross-sectional width of the second protrusion 14 along the thickness direction of the top cover assembly 100 can gradually decrease from the top cover 10 to the lower plastic 20. The embodiments of this application are not strictly limited in this respect, as long as the second protrusion 14 can be adapted and connected to the third mounting groove 45 of the upper plastic 40. In some other embodiments, the top cover 10 may not include the second protrusion 14.

[0114] For example, there may be two second protrusions 14, which may be spaced apart along the length of the top cover 10. Each second protrusion 14 is disposed around the outer edge of a first through hole 12 and is coaxial with and spaced apart from the first through hole 12.

[0115] The top cover 10 may also be provided with an explosion-proof hole 15 and a first liquid injection hole 16. Along the length of the top cover 10, the explosion-proof hole 15 is located between two first through holes 12 and is spaced apart from both first through holes 12. The explosion-proof hole 15 can penetrate the first surface 131 and the second surface 132. That is, the explosion-proof hole 15 penetrates the top cover body 13 along its thickness direction. The explosion-proof hole 15 is used to connect with the explosion-proof valve 60 and the explosion-proof valve protection plate 70. Along the length of the top cover 10, the first liquid injection hole 16 can be located between the explosion-proof hole 15 and the first through holes 12 and is spaced apart from both. The first liquid injection hole 16 can penetrate the first surface 131 and the second surface 132. That is, the first liquid injection hole 16 penetrates the top cover body 13 along its thickness direction. The first liquid injection hole 16 is used to inject electrolyte into the battery cell 220.

[0116] Please refer to the following: Figure 5 , Figure 7a , Figure 7b , Figure 8 and Figure 9 , Figure 7a yes Figure 3 The diagram shows an angled structural representation of the lower plastic 20 of the top cover assembly 100. Figure 7b yes Figure 7a The diagram shows another angle of the lower plastic 20. Figure 8 yes Figure 7a The diagram shows a structural schematic of the lower plastic 20 at another angle. Figure 9 It is along Figure 8 The diagram shows a cross-sectional view of the lower plastic 20 structure obtained by cutting along the cutting line BB.

[0117] The lower plastic 20 is connected to the first surface 131 of the top cover 10. A portion of the lower plastic 20 is located within the top cover 10. The lower plastic 20 can be used to accommodate the pole base 52 of the pole 50. That is, a portion of the lower plastic 20 is located between the top cover 10 and the pole base 52 of the pole 50. The portion of the lower plastic 20 facing away from the top cover 10 abuts against the surface of the pole base 52 near the pole body 51.

[0118] The lower plastic 20 may be provided with a second through hole 21. The second through hole 21 may penetrate the lower plastic 20 along its thickness direction (Z direction in the figure). The second through hole 21 is coaxially arranged and connected with the first through hole 12 of the top cover 10. The inner wall of the second through hole 21 is perpendicular to the surface of the lower plastic 20 away from the top cover 10 (within allowable tolerance). The inner wall of the second through hole 21 is a surface surrounding the central axis of the second through hole 21. The second through hole 21 can be used for the pole post 50 to pass through and to accommodate the third body 513 of the pole post 50. The inner wall of the second through hole 21 may be spaced apart from the outer peripheral surface of the third body 513 of the pole post 50. The outer peripheral surface of the third body 513 of the pole post 50 is an outer surface surrounding the central axis of the third body 513. The gap area between the inner wall of the second through hole 21 and the outer peripheral surface of the third body 513 of the pole post 50 can be used to accommodate part of the sealing ring 30. The inner wall of the second through hole 21 can be interference-fitted with the outer surface 31 of the sealing ring 30. The outer surface 31 of the sealing ring 30 is the outer surface surrounding the central axis of the sealing ring 30. That is, the outer surface 31 of the sealing ring 30 is the surface of the end of the sealing ring 30 closest to the lower plastic 20.

[0119] For example, there can be two second through holes 21. The two second through holes 21 can be spaced apart along the length direction (X direction in the figure) of the lower plastic 20. One second through hole 21 is used to install the positive terminal. The other second through hole 21 is used to install the negative terminal.

[0120] One possible implementation, such as Figure 7b As shown, the lower plastic 20 may be provided with a second mounting groove 22. The opening of the second mounting groove 22 is located on the surface of the lower plastic 20 opposite to the top cover 10, and is recessed into the interior of the lower plastic 20 from the surface of the lower plastic 20 opposite to the top cover 10. The second mounting groove 22 is coaxially arranged and connected to the second through hole 21. The cross-sectional width of the second mounting groove 22 along the thickness direction of the lower plastic 20 is greater than the cross-sectional width of the second through hole 21 along the thickness direction of the lower plastic 20. The second mounting groove 22 can be used to accommodate a portion of the pole post base 52 of the pole post 50. The bottom wall of the second mounting groove 22 abuts against the surface of the pole post base 52 of the pole post 50 near the pole post body 51. The bottom wall of the second mounting groove 22 and the opening of the second mounting groove 22 are arranged opposite each other in the thickness direction of the lower plastic 20. The inner peripheral wall of the second mounting groove 22 abuts against a portion of the outer peripheral surface of the pole post base 52. A portion of the pole post base 52 protrudes from the second mounting groove 22. The inner peripheral wall of the second mounting groove 22 is the surface surrounding the central axis of the second mounting groove 22. The outer peripheral surface of the pole post base 52 is the outer surface surrounding the central axis of the pole post base 52.

[0121] For example, there may be two second mounting slots 22, which are spaced apart along the length of the lower plastic 20. Each second mounting slot 22 is coaxially connected to and communicates with a second through hole 21, and can be used to accommodate a pole base 52 of a pole 50.

[0122] It is understandable that by providing a first protrusion 24 and a second mounting groove 22 on the lower plastic 20, and by having the inner wall of the second mounting groove 22 abut against the outer surface of the electrode base 52 of the electrode 50, the contact area between the lower plastic 20 and the electrode 50 can be effectively increased. This further increases the length of the path through which the electrolyte of the cell 220 penetrates into the top cover assembly 100, thereby reducing the penetration of the electrolyte into the top cover assembly 100 to a certain extent. This prevents the electrolyte from penetrating into the top cover assembly 100 and electrically connecting the electrode 50 with the top cover 10, thus preventing a decrease in the resistance of the electrode 50.

[0123] In this embodiment, the lower plastic 20 may include a lower plastic body 23 and a first protrusion 24. The first protrusion 24 is fixedly connected to the lower plastic body 23 and protrudes in the direction away from the battery cell 220. The first protrusion 24 and the lower plastic body 23 can be connected to form an integral structure.

[0124] The lower plastic body 23 may include a third surface 231 and a fourth surface 232. The third surface 231 and the fourth surface 232 are arranged opposite to each other in the thickness direction (Z direction in the figure) of the lower plastic body 23 and are respectively connected to both ends of the inner wall of the second through hole 21. The third surface 231 faces the battery cell 220. The fourth surface 232 is away from the battery cell 220. The fourth surface 232 is connected to the first surface 131 of the top cover 10. The lower plastic body 23 can be a one-piece structure. Alternatively, the lower plastic body 23 can be a split structure. Specifically, the lower plastic body 23 may include a first part and a second part. The first part and the second part are arranged sequentially in the length direction (X direction in the figure) of the lower plastic body 23. The first part and the second part are detachably connected. The detachable portion of the first part and the second part is as follows: Figure 7a , Figure 7b and Figure 8 As indicated by the dashed arrow.

[0125] The first protrusion 24 is fixedly connected to the fourth surface 232 of the top cover body 13 and protrudes relative to the fourth surface 232. The first protrusion 24 is located in the first mounting groove 11 of the top cover 10. The surface of the first protrusion 24 facing away from the top cover body 13 abuts against the bottom wall of the first mounting groove 11. The connection between the first protrusion 24 of the lower plastic 20 and the first mounting groove 11 of the top cover 10 helps to align and connect the lower plastic 20 and the top cover 10, improving the assembly efficiency of the top cover assembly 100 and the battery 200.

[0126] For example, there may be two first protrusions 24, spaced apart along the length of the lower plastic 20. Each first protrusion 24 is located within a first mounting groove 11 of a top cover 10. The lower plastic body 23 and the first protrusions 24 may be provided with the second through hole 21 and the second mounting groove 22 described above. The opening of the second mounting groove 22 may be located on the third surface 231. The second mounting groove 22 may be recessed into the lower plastic 20 from the third surface 231. The bottom wall of the second mounting groove 22 may be located within the lower plastic body 23, and the second through hole 21 may penetrate the first protrusion 24 and at least a portion of the lower plastic body 23 along the thickness direction of the lower plastic 20. Alternatively, the bottom wall of the second mounting groove 22 may be located within the first protrusion 24, and the second through hole 21 may penetrate a portion of the first protrusion 24 along the thickness direction of the lower plastic 20. Alternatively, the bottom wall of the second mounting groove 22 can be flush with the fourth surface 232, and the second through hole 21 can penetrate the first protrusion 24 along the thickness direction of the lower plastic 20.

[0127] In this embodiment, the lower plastic 20 may be provided with a positioning part 25. The positioning part 25 is connected to the fourth surface 232 of the lower plastic body 23 and is spaced apart from the first protrusion 24 in the width direction (Y direction in the figure) of the lower plastic 20. The cross-sectional width of the positioning part 25 along the thickness direction of the lower plastic 20 is smaller than the cross-sectional width of the first protrusion 24 along the thickness direction of the lower plastic 20. The positioning part 25 can be used to connect with the positioning groove 133 of the top cover 10.

[0128] The number of positioning portions 25 can be one or more. When there are multiple positioning portions 25, they can be spaced apart in the width direction of the lower plastic 20. Of course, in other embodiments, the multiple positioning portions 25 can also be spaced apart in the length direction of the lower plastic 20. Alternatively, the multiple positioning portions 25 can be spaced apart along the circumferential direction of the first protrusion 24. The circumferential direction of the first protrusion 24 is the direction surrounding the central axis of the first protrusion 24. The embodiments of this application do not strictly limit the spacing direction of the multiple positioning portions 25, as long as each positioning portion 25 is connected to a positioning groove 133 of the top cover 10.

[0129] For example, when there are two positioning parts 25, both positioning parts 25 are spaced apart from the first protrusion 24 in the width direction of the lower plastic 20. The distance between one positioning part 25 and the first protrusion 24 is equal to the distance between the other positioning part 25 and the first protrusion 24. Each positioning part 25 is inserted into a positioning groove 133 of a top cover 10.

[0130] Understandably, by providing a positioning part 25 on the lower plastic 20 and connecting the positioning part 25 with the positioning groove 133 on the top cover 10, the lower plastic 20 and the top cover 10 can be aligned and assembled more quickly, improving the overall production efficiency of the top cover assembly 100. At the same time, the connection between the positioning part 25 and the positioning groove 133 also enhances the connection stability between the lower plastic 20 and the top cover 10.

[0131] In other embodiments, grooves can be provided on the lower plastic 20 and protrusions can be provided on the top cover 10. The connection between the protrusions and grooves can also improve the connection efficiency and stability between the top cover 10 and the lower plastic 20.

[0132] In this embodiment, the lower plastic body 20 may be provided with a second injection hole 26. The second injection hole 26 may be disposed between two second through holes 21 and spaced apart from both second through holes 21. The second injection hole 26 may penetrate the third surface 231 and the fourth surface 232. That is, the second injection hole 26 may penetrate the lower plastic body 23 along the thickness direction of the lower plastic body 23. The second injection hole 26 is coaxially disposed and connected to the first injection hole 16 of the top cover 10, and is used to inject electrolyte into the battery cell 220.

[0133] Please refer to the following: Figure 5 , Figure 10a and Figure 10b , Figure 10a yes Figure 3 The diagram shows a structural schematic of one angle of the sealing ring 30 in the top cover assembly 100. Figure 10b yes Figure 10a A schematic diagram of the sealing ring 30 from another angle is shown.

[0134] The sealing ring 30 can be fitted onto the electrode body 51 of the electrode post 50 and elastically abut against the top cover 10 and the electrode base 52 of the electrode post 50. The sealing ring 30 can also be located between the fourth protrusion 44 of the upper plastic 40 and the electrode base 52 of the electrode post 50. Specifically, the sealing ring 30 is elastic; the surface of the sealing ring 30 facing away from the battery cell 220 can abut and press against the bottom of the first mounting groove 11 of the top cover 10, and is spaced apart from the fourth protrusion 44 of the upper plastic 40. The surface of the sealing ring 30 near the battery cell 220 can abut and press against the surface of the electrode base 52 of the electrode post 50 near the electrode body 51. Figure 5 The overlapping portion of the middle sealing ring 30 and the top cover 10 is the first compression zone of the sealing ring 30.

[0135] A portion of the sealing ring 30 is located within the second through hole 21 of the lower plastic 20 and is interference-fitted with the lower plastic 20. Specifically, the sealing ring 30 may include an outer surface 31, a bottom surface 32, and a top surface 36. The top surface 36 and the bottom surface 32 are arranged opposite to each other in the thickness direction (Z direction in the figure) of the sealing ring 30 and are respectively connected to both ends of the outer surface 31 of the sealing ring 30. The top surface 36 abuts against the bottom wall of the first mounting groove 11 of the top cover 10. The bottom surface 32 abuts against the surface of the pole base 52 of the pole 50 near the pole body 51. The outer surface 31 is interference-fitted with the inner wall of the second through hole 21 of the lower plastic 20. The outer surface 31 is perpendicular to the bottom surface 32 (within allowable tolerance). Figure 5 The overlapping portion of the middle sealing ring 30 and the lower plastic 20 is the second compression zone of the sealing ring 30.

[0136] Understandably, since the outer surface 31 of the sealing ring 30 is perpendicular to the bottom surface 32, in order to facilitate the assembly of the sealing ring 30 and the lower plastic 20, the inner wall of the second through hole 21 of the lower plastic 20 that abuts against the outer surface 31 of the sealing ring 30 can also be adjusted to be perpendicular to the surface of the lower plastic 20 away from the top cover 10. This makes it easier for the right-angled surface of the sealing ring 30 to be inserted into the second through hole 21 of the lower plastic 20 when assembling the lower plastic 20 and the sealing ring 30, which is beneficial to improving the assembly efficiency of the sealing ring 30 and the lower plastic 20.

[0137] Furthermore, since the sealing ring 30 and the lower plastic 20 can be in close contact, the electrolyte can be further prevented from penetrating into the top cover assembly 100, and the problem of the resistance of the top cover 10 and the electrode 50 decreasing due to the electrolyte penetrating into the gap between the top cover 10 and the electrode 50 is avoided.

[0138] In this embodiment, the sealing ring 30 may include a first state and a second state. The first state of the sealing ring 30 is a separated state in which the sealing ring 30 is not assembled with the lower plastic 20, and the second state of the sealing ring 30 is an assembled state in which the sealing ring 30 is assembled with the lower plastic 20.

[0139] Specifically, when the sealing ring 30 is in the first state, the sealing ring 30 is separated from the lower plastic 20, and the cross-sectional width of the sealing ring 30 along its thickness direction is a first width W1. When the sealing ring 30 is in the second state, the sealing ring 30 is interference-fitted with the lower plastic 20, and the cross-sectional width of the sealing ring 30 along its thickness direction is a second width W2. The second width W2 can be smaller than the first width W1.

[0140] Understandably, when the sealing ring 30 switches from the first state to the second state, the cross-sectional width of the sealing ring 30 along its thickness direction decreases. Therefore, when the sealing ring 30 is assembled with the upper plastic 40, it is laterally squeezed by the extrusion force of the upper plastic 40 perpendicular to the thickness direction of the sealing ring 30. That is, the direction in which the sealing ring 30 is squeezed by the lower plastic 20 is perpendicular to the bottom surface 32 of the sealing ring 30. This allows the lower plastic 20 to make close contact with the outer periphery of the sealing ring 30, which not only improves the connection strength between the sealing ring 30 and the lower plastic 20, but also further ensures that gaps are less likely to appear between the sealing ring 30 and the lower plastic 20, thus preventing electrolyte penetration and resulting in better reliability.

[0141] The difference between the first width W1 and the second width W2 is in the range of 3% to 5% of the first width W1 (including the endpoint values ​​of 3% and 5%). That is, the volume of the sealing ring 30 compressed by the lower plastic 20 ( Figure 5 The volume of the second compression zone (or the volume of the first compression zone and the second compression zone) of the sealing ring 30 accounts for 3% to 5% of the total volume of the sealing ring 30 (including the endpoint values ​​of 3% and 5%). That is, the compression of the sealing ring 30 can be in the range of 3% to 5% (including the endpoint values ​​of 3% and 5%).

[0142] Understandably, it has been verified that when the compression of the sealing ring 30 is within the range of 3% to 5%, it can effectively prevent electrolyte from penetrating into the gap between the terminal 50 and the top cover 10. Even if the battery 200 is inverted or flipped during production, assembly, and transportation, the resistance of the terminal 50 will not decrease and will remain at the value before electrolyte penetration, demonstrating strong stability.

[0143] A sealing ring 30 is fitted onto the pole body 51 of the pole post 50. Specifically, the sealing ring 30 may include a sealing ring body 33 and a connecting portion 34. The sealing ring body 33 is fitted onto the third body 513 of the pole post 50. The inner surface 35 of the sealing ring body 33 is spaced apart from the outer peripheral surface of the third body 513 of the pole post 50. The inner surface 35 of the sealing ring body 33 is the surface of the sealing ring body 33 away from the inner wall of the second through hole 21 of the lower plastic 20. The circumferential direction of the inner surface 35 of the sealing ring body 33 may be the direction surrounding the central axis of the inner surface 35. The outer surface 31 of the sealing ring body 33 is press-fitted to the inner wall of the second through hole 21 of the lower plastic 20. One end of the connecting portion 34 is connected to the inner surface 35 of the sealing ring body 33. The other end of the connecting portion 34 abuts against the third body 513 of the pole post 50. That is, the connecting portion 34 is located between the sealing ring body 33 and the third body 513 of the pole post 50. The connecting part 34 and the sealing ring 30 can be an integral structure. In this embodiment, the shape of the connecting part 34 is not limited.

[0144] The number of sealing rings 30 can be two. The two sealing rings 30 can be spaced apart along the length of the top cover assembly 100. One sealing ring 30 is fitted onto the positive terminal. The other sealing ring 30 is fitted onto the negative terminal. The number of connecting portions 34 can be one or more. One end of each connecting portion 34 is connected to the inner surface 35 of the sealing ring body 33, and the other end abuts against the terminal body 51 of the terminal 50. When there are multiple connecting portions 34, they can be spaced apart along the circumferential direction of the inner surface 35 of the sealing ring body 33. Providing connecting portions 34 on the sealing ring 30 enhances the connection stability between the sealing ring 30 and the terminal 50. Moreover, even if multiple connecting portions 34 are provided on the sealing ring 30, these connecting portions 34 are spaced apart. This not only saves space between the sealing ring 30 and the terminal 50 but also reduces costs.

[0145] Understandably, due to thermal expansion and assembly tolerances of the battery 200, there are generally certain gaps in the top cover assembly 100. For example, there are gaps between the terminal post 50 and the lower plastic 20, and between the sealing ring 30 and the lower plastic 20. However, after injecting electrolyte into the cell 220, subsequent production processes may involve inverting and flipping the battery 200, causing electrolyte to seep into the seepage paths formed by the gaps in the top cover assembly 100. The large number of ions present in the electrolyte will act as conductors, electrically connecting the terminal post 50 of the top cover assembly 100 to the top cover 10, resulting in a decrease in the resistance of the terminal post 50.

[0146] Therefore, in this embodiment, by making the sealing ring 30 and the lower plastic 20 interference fit, the gap between the sealing ring 30 and the lower plastic 20 can be eliminated, thereby blocking the electrolyte that has penetrated into the gap inside the top cover assembly 100 at the interference fit between the lower plastic 20 and the sealing ring 30. This prevents the electrolyte from entering the gap between the top cover 10 and the electrode post 50, causing the top cover 10 and the electrode post 50 to conduct electricity, which would lead to a decrease in the resistance of the electrode post 50.

[0147] For example, the outer diameter of the sealing ring 30 can be increased or the inner diameter of the lower plastic 20 can be decreased, so that the outer diameter of the sealing ring 30 is larger than the inner diameter of the lower plastic 20, thereby achieving an interference fit between the sealing ring 30 and the lower plastic 20.

[0148] Please refer to the following: Figure 5 , Figure 11a , Figure 11b and Figure 12 , Figure 11a yes Figure 3 The diagram shows a structural schematic of the upper plastic 40 of the top cover assembly 100 at an angle. Figure 11b yes Figure 3 The diagram shows a structural schematic of the upper plastic 40 of the top cover assembly 100 from another angle. Figure 12 It is along Figure 11a The diagram shows a cross-sectional view of the upper plastic 40 obtained by cutting along the cutting line CC.

[0149] The upper plastic 40 is installed on the top cover 10 and sleeved on the outside of the pole body 51 of the pole 50. A portion of the upper plastic 40 is located in the first through hole 12 of the top cover 10. A portion of the upper plastic 40 protrudes from the surface of the lower plastic 20 relative to the top cover 10. The upper plastic 40 may have a third through hole 41. The third through hole 41 can penetrate the upper plastic 40 along its thickness direction (Z direction in the figure). The third through hole 41 of the upper plastic 40 can be coaxially arranged and connected with the first through hole 12 of the top cover 10 and the second through hole 21 of the lower plastic 20. The third through hole 41 is used for the pole 50 to pass through and to accommodate the second body 512 and the third body 513 of the pole 50. The inner wall of the third through hole 41 can abut against the outer peripheral surfaces of the second body 512 and the third body 513 of the pole 50. The inner wall of the third through hole 41 is a surface surrounding the central axis of the third through hole 41. The outer peripheral surface of the second body 512 is the outer surface that surrounds the central axis of the second body 512.

[0150] The third through hole 41 may include a first hole 411 and a second hole 412. The first hole 411 and the second hole 412 are coaxially arranged and connected. The opening of the first hole 411 at the end away from the second hole 412 is located on the surface of the upper plastic 40 opposite to the top cover 10. The opening of the second hole 412 at the end away from the first hole 411 is located on the surface of the upper plastic 40 near the top cover 10. The cross-sectional width of the first hole 411 along the thickness direction of the upper plastic 40 is greater than the cross-sectional width of the second hole 412 along the thickness direction of the upper plastic 40. The first hole 411 of the upper plastic 40 is used to accommodate the second body 512 of the pole post 50. The second hole 412 of the upper plastic 40 is used to accommodate the third body 513 of the pole post 50.

[0151] The inner wall of the third through hole 41 is provided with a protruding structure a. The protruding structure a is used to connect with the recessed structure b on the outer peripheral surface of the pole post body 51. The shape of the protruding structure a can be adapted to the shape of the recessed structure b on the outer peripheral surface of the pole post body 51. The outer peripheral surface of the pole post body 51 is the outer surface surrounding the central axis of the pole post body 51. For example, the protruding structure a can be a mesh structure, a cross-shaped structure, a rhomboid structure, etc. The protruding structure a can be connected to the recessed structure b on the pole post 50 by means of snap-fit ​​or other connection methods. Providing the protruding structure a and the recessed structure b on the upper plastic 40 and the pole post 50 respectively can increase the connection stability between the upper plastic 40 and the pole post 50.

[0152] In this embodiment, a protrusion structure a can be provided on a portion of the inner wall of the third through hole 41, or a protrusion structure a can be provided on all the inner walls of the third through hole 41, as long as the inner wall of the third through hole 41 can be adapted and connected to the corresponding pole body 51.

[0153] For example, there can be two third through holes 41, which can be spaced apart along the length direction (X direction in the figure) of the upper plastic 40. One third through hole 41 is used for the positive terminal to pass through. The other third through hole 41 is used for the negative terminal to pass through. Furthermore, for the same third through hole 41, a protrusion structure a can be provided on the inner wall of the first hole 411 of the third through hole 411. Alternatively, a protrusion structure a can be provided on the inner wall of the second hole 412 of the third through hole 41. Alternatively, protrusion structures a can be provided on the inner walls of both the first hole 411 and the second hole 412 of the third through hole 41.

[0154] In this embodiment, the upper plastic 40 may include an upper plastic body 42, a third protrusion 43, and a fourth protrusion 44. The third through hole 41, as described above, is provided on the upper plastic body 42, the third protrusion 43, and the fourth protrusion 44, and extends along the thickness of the upper plastic 40.

[0155] The upper plastic body 42 may include a fifth surface 421 and a sixth surface 422. The fifth surface 421 and the sixth surface 422 are disposed opposite to each other in the thickness direction of the upper plastic 40. The fifth surface 421 faces the battery cell 220. The sixth surface 422 faces away from the battery cell 220. The fifth surface 421 is connected to the second surface 132 of the top cover 10.

[0156] The third protrusion 43 and the fourth protrusion 44 are coaxially arranged and opposite to each other in the thickness direction of the upper plastic 40. The third protrusion 43 is connected to the sixth surface 422. The fourth protrusion 44 is connected to the fifth surface 421. The fourth protrusion 44 is located in the first through hole 12 of the top cover 10. The fourth protrusion 44 can serve as insulation and is used to separate the top cover 10 from the pole post 50, preventing the top cover 10 and the pole post 50 from directly contacting each other and causing a short circuit.

[0157] For example, the third protrusion 43 and the upper plastic body 42 can cooperate to form the first hole 411 of the third through hole 41 described above. The first hole 411 can penetrate the third protrusion 43 and part of the upper plastic body 42 along the thickness direction of the upper plastic 40. The fourth protrusion 44 and the upper plastic body 42 can cooperate to form the second hole 412 of the first through hole 12 described above. The second hole 412 can penetrate the third protrusion 43 and part of the upper plastic body 42 along the thickness direction of the upper plastic 40. The upper plastic body 42, the third protrusion 43, and the fourth protrusion 44 can be an integral structure formed by connecting them by means such as integral molding.

[0158] In this embodiment, the upper plastic 40 is further provided with a third mounting groove 45. The opening of the third mounting groove 45 is located on the fifth surface 421. The third mounting groove 45 can be formed by recessing from the fifth surface 421 into the interior of the upper plastic body 42. The third mounting groove 45 is disposed around the outer edge of the fourth protrusion 44, and is coaxial with and spaced apart from the fourth protrusion 44. That is, the third mounting groove 45 is annular and surrounds the fourth protrusion 44. The third mounting groove 45 can be used to mount the second protrusion 14 of the top cover 10. The cross-sectional width of the third mounting groove 45 along the thickness direction of the upper plastic 40 gradually increases from the upper plastic 40 toward the top cover 10. In other embodiments, the cross-sectional width of the third mounting groove 45 along the thickness direction of the upper plastic 40 can remain unchanged, and there is no strict limitation on this, as long as the third mounting groove 45 can be adapted to connect with the second protrusion 14 of the top cover 10.

[0159] For example, there may be two third mounting slots 45, which may be spaced apart along the length of the top cover assembly 100. Each third mounting slot 45 is disposed around the outer edge of the fourth protrusion 44 and is coaxial with and spaced apart from the fourth protrusion 44.

[0160] The upper plastic 40 may also be provided with a mark 46. The mark 46 is adjacent to and spaced apart from the third through hole 41. The mark 46 may be located on the third protrusion 43. In other embodiments, the mark 46 may also be located on the upper plastic body 42. The mark 46 is used to mark the positive or negative polarity of the electrode 50 installed in the third through hole 41 of the upper plastic 40, so as to more efficiently align the third through hole 41 with the positive or negative electrode, and help the electrode 50 of the corresponding polarity to be installed in the corresponding third through hole 41.

[0161] For example, the number of identifiers 46 can be two. The two identifiers 46 are adjacent to and spaced apart from the two third through holes 41, respectively. A "+" shaped identifier 46 is provided around the third through hole 41 connected to the positive terminal. A "-" shaped identifier 46 is provided around the third through hole 41 connected to the negative terminal. Alternatively, the number of identifiers 46 can be four. Two "+" shaped identifiers 46 are provided around the third through hole 41 connected to the positive terminal. The two "+" shaped identifiers 46 are adjacent to and spaced apart from the corresponding third through hole 41 in the width direction (Y direction shown in the figure) of the upper plastic 40. Two "-" shaped identifiers 46 are provided around the third through hole 41 connected to the negative terminal. The two "-" shaped identifiers 46 are adjacent to and spaced apart from the corresponding third through hole 41 in the width direction of the upper plastic 40.

[0162] Please refer to the following: Figure 5 , Figure 13a and Figure 13b , Figure 13a yes Figure 3 The diagram shows a structural schematic of one configuration of the pole post 50 of the top cover assembly 100 in one state. Figure 13b yes Figure 13a The diagram shows the structure of pole post 50 in another state. Figure 14 yes Figure 3 Another structural schematic diagram of the pole post 50 of the top cover assembly 100 shown.

[0163] The electrode post 50 is mounted on the upper plastic 40, the top cover 10, and the lower plastic 20. The two opposite ends of the electrode post 50 protrude from the sixth surface 422 of the upper plastic 40 and the third surface 231 of the lower plastic 20, respectively. Specifically, the electrode post 50 may include an electrode post body 51 and an electrode post base 52. The electrode post base 52 is located on the side of the top cover 10 opposite to the upper plastic 40. One end of the electrode post body 51 is fixedly connected to the electrode post base 52. The electrode post body 51 passes through the second through hole 21 of the lower plastic 20, the first through hole 12 of the top cover 10, and the third through hole 41 of the upper plastic 40, and the other end of the electrode post body 51 extends out of the upper plastic 40.

[0164] The pole post body 51 may include a first body 511, a second body 512, and a third body 513. The first body 511, the second body 512, and the third body 513 are connected sequentially and coaxially. The third body 513 is connected to the pole post base 52, and the second body 512 is connected between the third body 513 and the first body 511. The cross-sectional width of the second body 512 along the thickness direction (Z direction in the figure) of the pole post 50 is greater than the cross-sectional width of the first body 511 along the thickness direction of the pole post 50, and also greater than the cross-sectional width of the third body 513 along the thickness direction of the pole post 50. The cross-sectional width of the pole post base 52 along the thickness direction of the pole post 50 is greater than the cross-sectional width of the pole post body 51 (including the first body 511, the second body 512, and the third body 513) along the thickness direction of the pole post 50.

[0165] Understandably, dividing the electrode post body 51 into three parts of different sizes allows for better installation of the upper plastic 40, top cover 10, lower plastic 20, and sealing ring 30 into their corresponding parts, preventing misalignment. Furthermore, the electrode post base 52 is larger than the electrode post body 51, effectively preventing the electrode post 50 from slipping off.

[0166] In one possible implementation, please refer to [the relevant documentation]. Figure 5 , Figure 13a and Figure 13bThe third body 513 includes a first sub-part 513a and a second sub-part 513b. One end of the first sub-part 513a is connected to the second body 512. The other end of the first sub-part 513a is connected to the second sub-part 513b, and the end of the second sub-part 513b away from the first sub-part 513a is connected to the pole post base 52. The cross-sectional width of the first sub-part 513a along the thickness direction of the pole post 50 is equal to the cross-sectional width of the second sub-part 513b along the thickness direction of the pole post 50. The first sub-part 513a can be connected with the first body 511 and the second body 512 to form an integral structure. The second sub-part 513b can be connected with the pole post base 52 to form an integral structure. The first sub-part 513a and the second sub-part 513b are detachably connected.

[0167] In this embodiment, the first body 511 of the electrode post 50 protrudes from the sixth surface 422 of the upper plastic 40. The second body 512 of the electrode post 50 is located within the third through hole 41 of the upper plastic 40. The third body 513 of the electrode post 50 is located within the third through hole 41 of the upper plastic 40, the first through hole 12 of the top cover 10, and the second through hole 21 of the lower plastic 20. A portion of the electrode post base 52 is located within the second mounting groove 22 of the lower plastic 20, and a portion protrudes from the third surface 231 of the lower plastic body 23.

[0168] That is, the upper plastic 40 is fitted onto the first sub-part 513a of the second body 512 and the third body 513 of the pole post 50. The inner wall of the first hole 411 of the third through hole 41 of the upper plastic 40 abuts against the outer peripheral surface of the second body 512 of the pole post 50. The inner wall of the second hole 412 of the third through hole 41 of the upper plastic 40 abuts against the outer peripheral surface of the first sub-part 513a of the third body 513. The outer peripheral surface of the first sub-part 513a is the outer surface surrounding the central axis of the first sub-part 513a. The top cover 10 is fitted onto the first sub-part 513a and the second sub-part 513b of the third body 513 of the pole post 50, and is separated from the pole post 50 by the fourth protrusion 44 of the upper plastic 40. A portion of the inner wall of the first through hole 12 of the top cover 10 abuts against the outer peripheral surface of the fourth protrusion 44 of the upper plastic 40. The outer peripheral surface of the fourth protrusion 44 is the outer surface surrounding the central axis of the fourth protrusion 44.

[0169] A sealing ring 30 is fitted onto the first sub-part 513a and the second sub-part 513b of the third body 513 of the pole post 50. The end of the connecting portion 34 of the sealing ring 30, away from the sealing ring body 33, abuts against a portion of the outer peripheral surface of the second sub-part 513b and a portion of the outer peripheral surface of the first sub-part 513a of the third body 513. The outer peripheral surface of the second sub-part 513b is the outer surface surrounding the central axis of the second sub-part 513b. The surface of the sealing ring 30 facing away from the upper plastic 40 abuts against the surface of the pole post base 52 near the pole post body 51. A lower plastic 20 is fitted onto the first sub-part 513a and the second sub-part 513b of the third body 513 and the pole post base 52. The second through hole 21 of the lower plastic 20 is separated from the third body 513 of the pole post 50 by the sealing ring 30. The inner wall of the second through hole 21 of the lower plastic 20 abuts against the outer surface 31 of the sealing ring 30. The inner peripheral wall of the second mounting groove of the lower plastic 20 abuts against a portion of the outer peripheral surface of the pole base 52. A portion of the pole base 52 protrudes from the third surface 231 of the lower plastic 20.

[0170] For another possible implementation, please refer to Figure 14 The same content as in the previous embodiment will not be repeated. The difference from the previous embodiment is that the first sub-part 513a and the second sub-part 513b are connected to form an integral structure. That is, the first body 511, the second body 512, and the third body 513 of the pole post base 52 and the pole post body 51 can be an integral structure.

[0171] In this embodiment, the first body 511 of the electrode post 50 protrudes from the sixth surface 422 of the upper plastic 40. The second body 512 of the electrode post 50 is located within the third through hole 41 of the upper plastic 40. The third body 513 of the electrode post 50 is located within the third through hole 41 of the upper plastic 40, the first through hole 12 of the top cover 10, and the second through hole 21 of the lower plastic 20. A portion of the electrode post base 52 is located within the second mounting groove 22 of the lower plastic 20, and a portion protrudes from the third surface 231 of the lower plastic body 23.

[0172] That is, the upper plastic 40 is fitted onto the second body 512 and part of the third body 513 of the pole post 50. The inner wall of the first hole 411 of the third through hole 41 of the upper plastic 40 abuts against the outer peripheral surface of the second body 512 of the pole post 50. The inner wall of the second hole 412 of the third through hole 41 of the upper plastic 40 abuts against part of the outer peripheral surface of the third body 513 of the pole post 50. The top cover 10 is fitted onto the third body 513 of the pole post 50 and is separated from the pole post 50 by the fourth protrusion 44 of the upper plastic 40. Part of the inner wall of the first through hole 12 of the top cover 10 abuts against the outer peripheral surface of the fourth protrusion 44 of the upper plastic 40. The sealing ring 30 is fitted onto the third body 513 of the pole post 50. The end of the connecting part 34 of the sealing ring 30 away from the inner side surface 35 of the sealing ring body 33 abuts against part of the outer peripheral surface of the third body 513 of the pole post 50. The sealing ring 30, facing away from the upper plastic 40, abuts against the surface of the pole post base 52 near the pole post body 51. The lower plastic 20 is fitted onto a portion of the third body 513 and a portion of the pole post base 52 of the pole post 50. The second through hole 21 of the lower plastic 20 is separated from the portion of the third body 513 of the pole post 50 by the sealing ring 30. The inner wall of the second through hole 21 of the lower plastic 20 abuts against the outer side 31 of the sealing ring 30. The inner peripheral wall of the second mounting groove 22 of the lower plastic 20 abuts against a portion of the outer peripheral surface of the pole post base 52. A portion of the pole post base 52 protrudes from the third surface 231 of the lower plastic 20.

[0173] In this embodiment, the outer peripheral surface of the pole body 51 is provided with a recessed structure b. The recessed structure b is used to connect with the protruding structure a on the inner wall of the third through hole 41 of the upper plastic 40. In other embodiments, the protruding structure a can also be provided on the outer peripheral surface of the pole body 51, and the recessed structure b can be provided on the inner wall of the third through hole 41 of the upper plastic 40. This is not strictly limited.

[0174] The recessed structure b can be provided on a portion of the outer peripheral surface of the pole post body 51, or it can be provided on all the outer peripheral surfaces of the pole post body 51. The requirement is that the outer peripheral surface of the pole post body 51 can be fitted and connected to the inner wall of the corresponding third through hole 41. It should be noted that the "all the outer peripheral surfaces of the pole post body 51" mentioned here does not include the outer peripheral surface of the first body 511. This is because the first body 511 of the pole post body 51 protrudes from the plastic 40, and the outer peripheral surface of the first body 511 is not connected to any structure.

[0175] For example, a recessed structure b can be provided on the outer peripheral surface of the second body 512 of the pole post 50. Alternatively, a recessed structure b can be provided on a portion of the outer peripheral surface of the third body 513 of the pole post 50. Alternatively, recessed structures b can be provided on both the outer peripheral surface of the second body 512 and a portion of the outer peripheral surface of the third body 513 of the pole post 50. The position of the recessed structure b must correspond to the position of the protruding structure a of the upper plastic 40.

[0176] Understandably, by setting the protruding structure a and the recessed structure b on the electrode post 50 and the upper plastic 40 respectively, it not only helps to align and connect the electrode post 50 and the upper plastic 40 more quickly, but also increases the connection stability between the electrode post 50 and the upper plastic 40, preventing the electrode post 50 from shaking or sliding.

[0177] Second embodiment:

[0178] Please refer to the following: Figure 15a , Figure 15b and Figure 16 , Figure 15a It is along Figure 3 The diagram shows a second cross-sectional view of a portion of the structure of the top cover assembly 100 obtained by cutting along section line AA. Figure 15b yes Figure 15a A magnified view of region L in the middle. Figure 16 yes Figure 3 This is a schematic diagram of an angle showing another structure of the sealing ring 30 of the top cover assembly 100. In this embodiment, the contents identical to those in the first embodiment will not be repeated. The differences from the first embodiment are the structure of the inner wall of the second through hole 21 of the lower plastic 20 and the structure of the outer surface 31 of the sealing ring 30. Furthermore, the description of the top cover assembly 100 below can be applied to the first embodiment above, unless otherwise specified.

[0179] The outer surface 31 of the sealing ring 30 may include a first connecting surface 311 and a second connecting surface 312. Both the first connecting surface 311 and the second connecting surface 312 are inclined relative to the thickness direction of the sealing ring 30 and extend along the circumferential direction of the sealing ring 30. The circumferential direction of the sealing ring 30 is the direction surrounding its central axis. The first connecting surface 311 and the second connecting surface 312 are connected. The included angle formed by the connection of the first connecting surface 311 and the second connecting surface 312 is a first included angle A1. The first connecting surface 311 is closer to the top cover 10 relative to the second connecting surface 312. That is, the end of the first connecting surface 311 away from the second connecting surface 312 is closer to the top surface 36 of the sealing ring 30. The end of the second connecting surface 312 away from the first connecting surface 311 is closer to the bottom surface 32 of the sealing ring 30. Specifically, the end of the first connecting surface 311 away from the second connecting surface 312 is connected to the top surface 36 of the sealing ring 30, and / or, the end of the second connecting surface 312 away from the first connecting surface 311 is connected to the bottom surface 32 of the sealing ring 30. Alternatively, the first connecting surface 311 and the top surface 36 of the sealing ring 30 are spaced apart, and the second connecting surface 312 and the bottom surface 32 of the sealing ring 30 are spaced apart. Exemplarily, the inclination direction of the first connecting surface 311 relative to the thickness direction of the sealing ring 30 is opposite to the inclination direction of the second connecting surface 312 relative to the thickness direction of the sealing ring 30.

[0180] The outer surface 31 of the sealing ring 30 may further include a first transition surface 313. The first transition surface 313 may extend along the circumferential direction of the sealing ring 30. The first connecting surface 311 and the second connecting surface 312 may be connected by the first transition surface 313. The first transition surface 313 is used to prevent the connection between the first connecting surface 311 and the second connecting surface 312 from being too sharp and scratching the lower plastic 20. Exemplarily, the first transition surface 313 may be an arc surface. Of course, in other embodiments, the first connecting surface 311 and the second connecting surface 312 may also be directly connected. The connection between the first connecting surface 311 and the second connecting surface 312 extends along the circumferential direction of the sealing ring 30.

[0181] Please refer to the following: Figure 15a , Figure 15b , Figure 17 and Figure 18 , Figure 17 yes Figure 3 The diagram shows an angled view of another structure of the lower plastic 20 of the top cover assembly 100. Figure 18 It is along Figure 17 The diagram shows another cross-sectional view of the lower plastic 20 structure obtained by cutting along the cutting line DD.

[0182] The inner wall of the second through hole 21 of the lower plastic 20 may include a first contact surface 211 and a second contact surface 212. Both the first contact surface 211 and the second contact surface 212 are inclined relative to the thickness direction of the lower plastic 20 and extend along the circumferential direction of the second through hole 21. The circumferential direction of the second through hole 21 is the direction surrounding its central axis. The first contact surface 211 and the second contact surface 212 are connected. The included angle formed by the connection of the first contact surface 211 and the second contact surface 212 is a second included angle A2. The end of the first contact surface 211 away from the second contact surface 212 is close to the fourth surface 232 of the lower plastic 20. The end of the second contact surface 212 away from the first contact surface 211 is close to the third surface 231 of the lower plastic 20. Specifically, the end of the first contact surface 211 away from the second contact surface 212 is connected to the fourth surface 232 of the lower plastic 20, and / or, the end of the second contact surface 212 away from the first contact surface 211 is connected to the third surface 231 of the lower plastic 20. Alternatively, the first contact surface 211 and the fourth surface 232 of the lower plastic 20 are spaced apart, and the second contact surface 212 and the third surface 231 of the lower plastic 20 are spaced apart. Exemplarily, the inclination direction of the first contact surface 211 relative to the thickness direction of the lower plastic 20 is opposite to the inclination direction of the second contact surface 212 relative to the thickness direction of the lower plastic 20.

[0183] The first contact surface 211 is interference-fitted with at least a portion of the first connecting surface 311 of the sealing ring 30, and / or, the second contact surface 212 is interference-fitted with at least a portion of the second connecting surface 312 of the sealing ring 30. In some other embodiments, the first contact surface 211 is interference-fitted with at least a portion of the second connecting surface 312 of the sealing ring 30, and / or, the second contact surface 212 is interference-fitted with at least a portion of the first connecting surface 311 of the sealing ring 30.

[0184] For example, the first contact surface 211 is interference-fitted with a portion of the first connecting surface 311 of the sealing ring 30, and a gap exists between the second contact surface 212 and the second connecting surface 312 of the sealing ring 30. Alternatively, the first contact surface 211 is interference-fitted with a portion of the first connecting surface 311 of the sealing ring 30, and the second contact surface 212 is interference-fitted with a portion of the second connecting surface 312 of the sealing ring 30. Alternatively, the first contact surface 211 is interference-fitted with a portion of the first connecting surface 311 of the sealing ring 30, and the second contact surface 212 is interference-fitted with all the second connecting surfaces 312 of the sealing ring 30. Alternatively, the first contact surface 211 is interference-fitted with all the first connecting surfaces 311 of the sealing ring 30, and a gap exists between the second contact surface 212 and the second connecting surface 312 of the sealing ring 30. Alternatively, the first contact surface 211 is interference-fitted with all the first connecting surfaces 311 of the sealing ring 30, and the second contact surface 212 is interference-fitted with a portion of the second connecting surface 312 of the sealing ring 30. Alternatively, the first contact surface 211 is interference-fitted with all the first connecting surfaces 311 of the sealing ring 30, and the second contact surface 212 is interference-fitted with all the second connecting surfaces 312 of the sealing ring 30. Alternatively, there is a gap between the first contact surface 211 and the first connecting surfaces 311 of the sealing ring 30, and the second contact surface 212 is interference-fitted with a portion of the second connecting surfaces 312 of the sealing ring 30. Alternatively, there is a gap between the first contact surface 211 and the first connecting surfaces 311 of the sealing ring 30, and the second contact surface 212 is interference-fitted with all the second connecting surfaces 312 of the sealing ring 30.

[0185] It is understandable that by making the inner wall of the second through hole 21 of the lower plastic 20 include a first contact surface 211 and a second contact surface 212, and making both the first contact surface 211 and the second contact surface 212 inclined relative to the thickness direction of the lower plastic 20, the inner wall of the second through hole 21 of the lower plastic 20 can be a bent surface with an included angle, thereby increasing the contact area between the lower plastic 20 and the sealing ring 30, changing the shape of the electrolyte penetration path in the top cover assembly 100 from a straight line to a curve, thereby further increasing the length of the penetration path, increasing the difficulty of electrolyte penetration into the interior of the top cover assembly 100, and further preventing the electrolyte from penetrating into the gap between the top cover 10 and the electrode post 50, causing the top cover 10 and the electrode post 50 to be electrically connected, resulting in a decrease in the resistance of the electrode post 50.

[0186] In this embodiment, the first included angle A1 of the sealing ring 30 can be greater than the second included angle A2 of the lower plastic 20. This ensures an interference fit between the sealing ring 30 and the lower plastic 20, making the outer side 31 of the sealing ring 30 and the inner wall of the second through hole 21 of the lower plastic 20 fit more tightly, which is beneficial to improving the connection stability and reliability between the sealing ring 30 and the lower plastic 20.

[0187] The inner wall of the second through hole 21 of the lower plastic 20 may also include a second transition surface 213. The second transition surface 213 may extend along the circumferential direction of the second through hole 21. The first contact surface 211 and the second contact surface 212 may be connected by the second transition surface 213. The second transition surface 213 is used to prevent the sealing ring 30 from being scratched due to excessive sharpness at the connection between the first contact surface 211 and the second contact surface 212. Exemplarily, the second transition surface 213 may be an arc surface. Of course, in other embodiments, the first contact surface 211 and the second contact surface 212 may also be directly connected. The connection between the first contact surface 211 and the second contact surface 212 extends along the circumferential direction of the second through hole 21.

[0188] In one possible application scenario, please refer to the relevant documentation. Figure 15a and Figure 15b The end of the first connecting surface 311 of the sealing ring 30 away from the second connecting surface 312 is connected to the top surface 36 of the sealing ring 30. The end of the second connecting surface 312 of the sealing ring 30 away from the first connecting surface 311 is connected to the bottom surface 32 of the sealing ring 30. The first connecting surface 311 and the second connecting surface 312 are connected by a first transition surface 313. The first transition surface 313 is arc-shaped. The cross-sectional width of the first connecting surface 311 in the thickness direction of the sealing ring 30 gradually increases from the top surface 36 to the bottom surface 32. The cross-sectional width of the second connecting surface 312 in the thickness direction of the sealing ring 30 gradually decreases from the top surface 36 to the bottom surface 32. The cross-sectional width of the first transition surface 313 in the thickness direction of the sealing ring 30 first increases and then decreases from the top surface 36 to the bottom surface 32. That is, the cross-sectional width of the sealing ring 30 in the thickness direction first increases and then decreases from the top surface 36 to the bottom surface 32. The outer surface 31 of the sealing ring 30 is shaped like a "C", with the opening of the "C" facing the pole post 50.

[0189] The first contact surface 211 of the lower plastic 20, away from the second contact surface 212, is connected to the fourth surface 232. The second contact surface 212 of the lower plastic 20, away from the first contact surface 211, is connected to the third surface 231. The first contact surface 211 and the second contact surface 212 are connected by a second transition surface 213. The second transition surface 213 is arc-shaped. The cross-sectional width of the first contact surface 211 in the thickness direction of the lower plastic 20 gradually increases from the fourth surface 232 to the third surface 231. The cross-sectional width of the second contact surface 212 in the thickness direction of the lower plastic 20 gradually decreases from the fourth surface 232 to the third surface 231. The cross-sectional width of the second transition surface 213 in the thickness direction of the lower plastic 20 first increases and then decreases from the fourth surface 232 to the third surface 231. That is, the cross-sectional width of the inner wall of the second through hole 21 of the lower plastic 20 in the thickness direction of the lower plastic 20 first increases and then decreases from the fourth surface 232 to the third surface 231. The inner wall of the second through hole 21 is C-shaped, and the opening of the C faces the outer side 31 of the sealing ring 30.

[0190] The first contact surface 211 of the lower plastic 20 is interference-fitted with the first connecting surface 311 and part of the first transition surface 313 of the sealing ring 30. A gap exists between the second contact surface 212 of the lower plastic 20 and the second connecting surface 312 of the sealing ring 30. In this embodiment, the first width W1 is greater than the second width W2.

[0191] It is understandable that by making the first contact surface 211 of the lower plastic 20 interference-fit with the first connecting surface 311 and part of the first transition surface 313 of the sealing ring 30, the electrolyte can be blocked at the interference-fit point between the lower plastic 20 and the sealing ring 30, preventing the electrolyte from entering the gap between the top cover 10 and the electrode 50, thus electrically connecting the top cover 10 and the electrode 50 and reducing the resistance of the electrode 50.

[0192] In this embodiment, the assembly process of the top cover assembly 100 may include at least the following steps:

[0193] First, install the electrode post 50 onto the lower plastic 20, so that the electrode post body 51 of the electrode post 50 passes through the second through hole 21 of the lower plastic 20, and so that the electrode post base 52 of the electrode post 50 abuts against the lower plastic 20.

[0194] Next, the sealing ring 30 is fitted onto the electrode body 51 of the electrode post 50 from above. The second connecting surface 312 of the sealing ring 30 is first pressed into the second through hole 21 of the lower plastic 20, and then the first connecting surface 311 of the sealing ring 30 is pressed into the second through hole 21 of the lower plastic 20, so that the sealing ring 30 and the lower plastic 20 are interference-fitted, and the surface of the sealing ring 30 facing away from the upper plastic 40 abuts against the electrode base 52 of the electrode post 50. In some other embodiments, the first connecting surface 311 of the sealing ring 30 may be pressed into the second through hole 21 of the lower plastic 20 first, and then the second connecting surface 312 of the sealing ring 30 may be pressed into the second through hole 21 of the lower plastic 20. That is, the sealing ring 30 does not need to be installed with a distinction between the front and back sides.

[0195] Third embodiment:

[0196] Please refer to the following: Figure 19a and Figure 19b , Figure 19a It is along Figure 3 The diagram shows a third cross-sectional view of a portion of the top cover assembly 100 obtained by cutting along section line AA. Figure 19b yes Figure 19a Enlarged view of region M. In this embodiment, the contents identical to those in the second embodiment will not be repeated. The difference is that the first connecting surface 311 in the sealing ring 30 is parallel to the thickness direction of the sealing ring 30. The first contact surface 211 in the lower plastic 20 is parallel to the thickness direction of the lower plastic 20. That is, the first connecting surface 311 is perpendicular to the bottom surface 32 and / or top surface 36 of the sealing ring 30 (within allowable tolerance). The first contact surface 211 is perpendicular to the fourth surface 232 and / or third surface 231 of the lower plastic 20 (within allowable tolerance). Furthermore, the description of the top cover assembly 100 below can be applied to both the first and second embodiments described above, unless otherwise specified.

[0197] Understandably, designing the first connecting surface 311 of the sealing ring 30 at a right angle relative to the bottom surface 32, and designing the first contact surface 211 of the lower plastic 20 at a right angle to the fourth surface 232, allows the right-angled surface of the sealing ring 30 to directly fall into the lower plastic 20 during assembly, without prior pressing. Furthermore, the right-angle design also serves as a guide during the assembly of the lower plastic 20 and the sealing ring 30. In summary, making one of the interference fit surfaces of the sealing ring 30 and the lower plastic 20 beveled increases the leakage path in the top cover assembly 100, while making the other interference fit surface of the sealing ring 30 and the lower plastic 20 at a right angle saves pressing time and improves production efficiency.

[0198] In one possible application scenario, please continue to refer to [the relevant documentation / references]. Figure 19a and Figure 19b The first connecting surface 311 of the sealing ring 30, away from the second connecting surface 312, is connected to the top surface 36 of the sealing ring 30. The first connecting surface 311 is perpendicular to the bottom surface 32 and / or the top surface 36 of the sealing ring 30. The second connecting surface 312 of the sealing ring 30, away from the first connecting surface 311, is connected to the bottom surface 32 of the sealing ring 30. The first connecting surface 311 and the second connecting surface 312 are connected by a first transition surface 313. The first transition surface 313 is arc-shaped. The cross-sectional width of the first connecting surface 311 in the thickness direction of the sealing ring 30 remains constant from the top surface 36 to the bottom surface 32. The cross-sectional width of the second connecting surface 312 in the thickness direction of the sealing ring 30 gradually decreases from the top surface 36 to the bottom surface 32. The cross-sectional width of the first transition surface 313 in the thickness direction of the sealing ring 30 gradually decreases from the top surface 36 to the bottom surface 32. That is, the cross-sectional width of the sealing ring 30 in the thickness direction remains constant from the top surface 36 to the bottom surface 32 and then gradually decreases. The outer surface 31 of the sealing ring 30 is in the shape of a semi-"C", with the opening of the "C" facing the pole post 50.

[0199] The first contact surface 211 of the lower plastic 20, away from the second contact surface 212, is connected to the fourth surface 232. The first contact surface 211 is perpendicular to the fourth surface 232 and / or the third surface 231 of the lower plastic 20. The second contact surface 212 of the lower plastic 20, away from the first contact surface 211, is connected to the third surface 231. The first contact surface 211 and the second contact surface 212 are connected by a second transition surface 213. The second transition surface 213 is arc-shaped. The cross-sectional width of the first contact surface 211 in the thickness direction of the lower plastic 20 remains constant from the fourth surface 232 to the third surface 231. The cross-sectional width of the second contact surface 212 in the thickness direction of the lower plastic 20 gradually decreases from the fourth surface 232 to the third surface 231. The cross-sectional width of the second transition surface 213 in the thickness direction of the lower plastic 20 gradually decreases from the fourth surface 232 to the third surface 231. That is, the cross-sectional width of the inner wall of the second through hole 21 in the thickness direction of the lower plastic 20 remains constant from the fourth surface 232 to the third surface 231 and then gradually decreases. The inner wall of the second through hole 21 of the lower plastic 20 is in the shape of a semi-"C", with the opening of the "C" facing the outer side 31 of the sealing ring 30.

[0200] The first contact surface 211 of the lower plastic 20 is interference-fitted with the first connecting surface 311 and the first transition surface 313 of the sealing ring 30. A gap exists between the second contact surface 212 of the lower plastic 20 and the second connecting surface 312 of the sealing ring 30. In this embodiment, the first width W1 is greater than the second width W2.

[0201] Understandably, by interfering the first contact surface 211 of the lower plastic 20 with the first connecting surface 311 and the first transition surface 313 of the sealing ring 30, the electrolyte can be blocked at the interference connection between the lower plastic 20 and the sealing ring 30, preventing the electrolyte from entering the gap between the top cover 10 and the electrode 50, thus electrically connecting the top cover 10 and the electrode 50 and reducing the resistance of the electrode 50.

[0202] In this embodiment, the assembly process of the top cover assembly 100 may include at least the following steps:

[0203] First, install the electrode post 50 onto the lower plastic 20, so that the electrode post body 51 of the electrode post 50 passes through the second through hole 21 of the lower plastic 20, and so that the electrode post base 52 of the electrode post 50 abuts against the lower plastic 20.

[0204] Next, the sealing ring 30 is fitted onto the electrode body 51 of the electrode 50 from above, and the second connecting surface 312 of the sealing ring 30 is pressed into the second through hole 21 of the lower plastic 20. Then, the first connecting surface 311 of the sealing ring 30 can enter the second through hole 21 of the lower plastic 20 under the guiding action, so that the sealing ring 30 is interference-fitted with the lower plastic 20, and the surface of the sealing ring 30 facing away from the upper plastic 40 abuts against the electrode base 52 of the electrode 50.

[0205] Fourth embodiment:

[0206] Please refer to the following: Figure 20a and Figure 20b , Figure 20a It is along Figure 3 The diagram shows a fourth cross-sectional view of a portion of the top cover assembly 100 obtained by cutting along section line AA. Figure 20b yes Figure 20a Enlarged view of region N. In this embodiment, the contents identical to those in the second embodiment will not be repeated. The difference is that the second connecting surface 312 in the sealing ring 30 is parallel to the thickness direction of the sealing ring 30. The second contact surface 212 in the lower plastic 20 is parallel to the thickness direction of the lower plastic 20. That is, the second connecting surface 312 is perpendicular to the bottom surface 32 and / or top surface 36 of the sealing ring 30 (within allowable tolerance). The second contact surface 212 is perpendicular to the third surface 231 and / or fourth surface 232 of the lower plastic 20 (within allowable tolerance). Furthermore, the description of the top cover assembly 100 below can be applied to the first to third embodiments described above, unless otherwise specified.

[0207] It is understandable that designing the second connecting surface 312 of the sealing ring 30 at a right angle relative to the bottom surface 32, and designing the second contact surface 212 of the lower plastic 20 at a right angle to the fourth surface 232, can also allow the right-angled surface of the sealing ring 30 to fall directly into the lower plastic 20 during assembly, saving pressing time and improving production efficiency.

[0208] In one possible application scenario, please continue to refer to [the relevant documentation / references]. Figure 20a and Figure 20b The first connecting surface 311 of the sealing ring 30, away from the second connecting surface 312, is connected to the top surface 36 of the sealing ring 30. The second connecting surface 312 of the sealing ring 30, away from the first connecting surface 311, is connected to the bottom surface 32 of the sealing ring 30. The second connecting surface 312 is perpendicular to the bottom surface 32 and / or the top surface 36 of the sealing ring 30. The first connecting surface 311 and the second connecting surface 312 are connected by a first transition surface 313. The first transition surface 313 is arc-shaped. The cross-sectional width of the first connecting surface 311 in the thickness direction of the sealing ring 30 gradually increases from the top surface 36 to the bottom surface 32. The cross-sectional width of the second connecting surface 312 in the thickness direction of the sealing ring 30 remains unchanged from the top surface 36 to the bottom surface 32. The cross-sectional width of the first transition surface 313 in the thickness direction of the sealing ring 30 gradually increases from the top surface 36 to the bottom surface 32. That is, the cross-sectional width of the sealing ring 30 in the thickness direction gradually increases from the top surface 36 to the bottom surface 32 and then remains constant. The outer surface 31 of the sealing ring 30 is in the shape of a semi-"C", with the opening of the "C" facing the pole post 50.

[0209] The first contact surface 211 of the lower plastic 20, away from the second contact surface 212, is connected to the fourth surface 232. The second contact surface 212 of the lower plastic 20, away from the first contact surface 211, is connected to the third surface 231. The second contact surface 212 is perpendicular to the third surface 231 and / or the fourth surface 232 of the lower plastic 20. The first contact surface 211 and the second contact surface 212 are connected by a second transition surface 213. The second transition surface 213 is arc-shaped. The cross-sectional width of the first contact surface 211 in the thickness direction of the lower plastic 20 gradually increases from the fourth surface 232 to the third surface 231. The cross-sectional width of the second contact surface 212 in the thickness direction of the lower plastic 20 remains unchanged from the fourth surface 232 to the third surface 231. The cross-sectional width of the second transition surface 213 in the thickness direction of the lower plastic 20 gradually increases from the fourth surface 232 to the third surface 231. That is, the cross-sectional width of the inner wall of the second through hole 21 in the thickness direction of the lower plastic 20 gradually increases from the fourth surface 232 to the third surface 231 and then remains constant. The inner wall of the second through hole 21 of the lower plastic 20 is in the shape of a semi-"C", with the opening of the "C" facing the outer side 31 of the sealing ring 30.

[0210] The first contact surface 211 of the lower plastic 20 is interference-fitted with the first connecting surface 311 and the first transition surface 313 of the sealing ring 30. A gap exists between the second contact surface 212 of the lower plastic 20 and the second connecting surface 312 of the sealing ring 30. In this embodiment, the first width W1 is equal to the second width W2.

[0211] Understandably, by interfering the first contact surface 211 of the lower plastic 20 with the first connecting surface 311 and the first transition surface 313 of the sealing ring 30, the electrolyte can be blocked at the interference connection between the lower plastic 20 and the sealing ring 30, preventing the electrolyte from entering the gap between the top cover 10 and the electrode 50, thus electrically connecting the top cover 10 and the electrode 50 and reducing the resistance of the electrode 50.

[0212] In this embodiment, the assembly process of the top cover assembly 100 may include at least the following steps:

[0213] First, install the electrode post 50 onto the lower plastic 20, so that the electrode post body 51 of the electrode post 50 passes through the second through hole 21 of the lower plastic 20, and so that the electrode post base 52 of the electrode post 50 abuts against the lower plastic 20.

[0214] Next, the sealing ring 30 is fitted onto the electrode body 51 of the electrode post 50 from above. The second connecting surface 312 of the sealing ring 30 can be pressed into the second through hole 21 of the lower plastic 20 under the guidance. Then, the first connecting surface 311 of the sealing ring 30 can be interference-fitted with the second contact surface 212 of the lower plastic 20. Then, the electrode post 50 is installed on the top cover 10, so that the top cover 10 compresses the sealing ring 30 and the surface of the sealing ring 30 facing away from the upper plastic 40 abuts against the electrode base 52 of the electrode post 50.

[0215] Fifth embodiment:

[0216] Please refer to the following: Figure 21a and Figure 21b , Figure 21a It is along Figure 3 The diagram shows a fifth cross-sectional view of a portion of the top cover assembly 100 obtained by cutting along section line AA. Figure 21b yes Figure 21a Enlarged view of region O in the middle. In this embodiment, the same content as in the second embodiment will not be repeated. The difference from the second embodiment is that the first included angle A1 of the sealing ring 30 is smaller than the second included angle A2 of the lower plastic 20. Specifically, in this embodiment, the inclination direction of the first connecting surface 311 and the second connecting surface 312 of the sealing ring 30 relative to the thickness direction of the sealing ring 30 is opposite to that in the second embodiment. In this embodiment, the inclination direction of the first contact surface 211 and the second contact surface 212 of the upper plastic 40 relative to the thickness direction of the lower plastic 20 is opposite to that in the second embodiment. This ensures that the bending angle on the inner wall of the upper plastic 40 is located within the bending angle on the outer surface 31 of the sealing ring 30. Furthermore, the description of the top cover assembly 100 below can be applied to the first to fourth embodiments described above, unless otherwise specified.

[0217] It is understandable that in this embodiment, the inner wall of the second through hole 21 of the lower plastic 20 and the outer side 31 of the sealing ring 30 can also be bent surfaces with an angle, thereby increasing the length of the penetration path and making it more difficult for the electrolyte to penetrate into the top cover assembly 100. This avoids the electrolyte from penetrating into the gap between the top cover 10 and the electrode 50, causing the top cover 10 and the electrode 50 to be electrically connected, which would lead to a decrease in the resistance of the electrode 50.

[0218] In one possible application scenario, please continue to refer to [the relevant documentation / references]. Figure 21a and Figure 21bThe first connecting surface 311 of the sealing ring 30, away from the second connecting surface 312, is spaced apart from the top surface 36 of the sealing ring 30. The second connecting surface 312 of the sealing ring 30, away from the first connecting surface 311, is spaced apart from the bottom surface 32 of the sealing ring 30. The first connecting surface 311 and the second connecting surface 312 are connected by a first transition surface 313. The first transition surface 313 is arc-shaped. The cross-sectional width of the first connecting surface 311 in the thickness direction of the sealing ring 30 gradually decreases from the top surface 36 to the bottom surface 32. The cross-sectional width of the second connecting surface 312 in the thickness direction of the sealing ring 30 gradually increases from the top surface 36 to the bottom surface 32. The cross-sectional width of the first transition surface 313 in the thickness direction of the sealing ring 30 first decreases and then increases from the top surface 36 to the bottom surface 32. That is, the cross-sectional width of the sealing ring 30 in the thickness direction first remains constant, then decreases, then increases, and then remains constant again from the top surface 36 to the bottom surface 32. The outer side 31 of the sealing ring 30 is shaped like a "C", with the opening of the "C" facing downwards towards the plastic 20.

[0219] The first contact surface 211 of the lower plastic 20, away from the second contact surface 212, is connected to the fourth surface 232. The second contact surface 212 of the lower plastic 20, away from the first contact surface 211, is connected to the third surface 231. The first contact surface 211 and the second contact surface 212 are connected by a second transition surface 213. The second transition surface 213 is arc-shaped. The cross-sectional width of the first contact surface 211 in the thickness direction of the lower plastic 20 gradually decreases from the fourth surface 232 to the third surface 231. The cross-sectional width of the second contact surface 212 in the thickness direction of the lower plastic 20 gradually increases from the fourth surface 232 to the third surface 231. The cross-sectional width of the second transition surface 213 in the thickness direction of the lower plastic 20 first decreases and then increases from the fourth surface 232 to the third surface 231. That is, the cross-sectional width of the inner wall of the second through hole 21 of the lower plastic 20 in the thickness direction of the lower plastic 20 first decreases and then increases from the fourth surface 232 to the third surface 231. The inner wall of the second through hole 21 is C-shaped, and the opening of the "C" is away from the sealing ring 30.

[0220] The first contact surface 211 of the lower plastic 20 is interference-fitted with the first connecting surface 311 of the sealing ring 30. The second contact surface 212 of the lower plastic 20 is interference-fitted with the second connecting surface 312 of the sealing ring 30. In this embodiment, the first width W1 is equal to the second width W2.

[0221] This embodiment can block the electrolyte at the interference fit between the lower plastic 20 and the sealing ring 30, preventing the electrolyte from entering the gap between the top cover 10 and the electrode 50, thus electrically connecting the top cover 10 and the electrode 50 and reducing the resistance of the electrode 50.

[0222] In this embodiment, the assembly process of the top cover assembly 100 may include at least the following steps:

[0223] First, install the electrode post 50 onto the lower plastic 20, so that the electrode post body 51 of the electrode post 50 passes through the second through hole 21 of the lower plastic 20, and so that the electrode post base 52 of the electrode post 50 abuts against the lower plastic 20.

[0224] Next, the sealing ring 30 is fitted onto the electrode body 51 of the electrode post 50 from above, and the second connecting surface 312 of the sealing ring 30 is pressed to abut against the second contact surface 212 of the lower plastic 20. Then, the first connecting surface 311 of the sealing ring 30 is pressed to abut against the first contact surface 211 of the lower plastic 20, so that the sealing ring 30 and the lower plastic 20 are interference-fitted, and the surface of the sealing ring 30 facing away from the upper plastic 40 abuts against the electrode base 52 of the electrode post 50. In some other embodiments, the sealing ring 30 can be installed without distinguishing between the front and back sides.

[0225] Sixth embodiment:

[0226] Please refer to the following: Figure 22a and Figure 22b , Figure 22a It is along Figure 3 The diagram shows a sixth cross-sectional view of a portion of the top cover assembly 100 obtained by cutting along section line AA. Figure 22b yes Figure 22a Enlarged view of region P. In this embodiment, the contents identical to those in the fifth embodiment will not be repeated. The difference is that the first connecting surface 311 in the sealing ring 30 is parallel to the thickness direction of the sealing ring 30. The first contact surface 211 in the lower plastic 20 is parallel to the thickness direction of the lower plastic 20. That is, the first connecting surface 311 is perpendicular to the bottom surface 32 and / or top surface 36 of the sealing ring 30 (within allowable tolerance). The first contact surface 211 is perpendicular to the fourth surface 232 and / or third surface 231 of the lower plastic 20 (within allowable tolerance). Furthermore, the description of the top cover assembly 100 below can be applied to the first to fifth embodiments described above, unless otherwise specified.

[0227] Understandably, setting one of the interference surfaces of the sealing ring 30 and the lower plastic 20 as an angle can increase the leakage path in the top cover assembly 100, while designing the other interference surface of the sealing ring 30 and the lower plastic 20 as a right angle can save pressing time and improve production efficiency.

[0228] In one possible application scenario, please continue to refer to [the relevant documentation / references]. Figure 22a and Figure 22bThe first connecting surface 311 of the sealing ring 30, away from the second connecting surface 312, is connected to the top surface 36 of the sealing ring 30. The first connecting surface 311 is perpendicular to the bottom surface 32 and / or the top surface 36 of the sealing ring 30. The second connecting surface 312 of the sealing ring 30, away from the first connecting surface 311, is spaced apart from the bottom surface 32 of the sealing ring 30. The first connecting surface 311 and the second connecting surface 312 are connected by a first transition surface 313. The first transition surface 313 is arc-shaped. The cross-sectional width of the first connecting surface 311 in the thickness direction of the sealing ring 30 remains constant from the top surface 36 to the bottom surface 32. The cross-sectional width of the second connecting surface 312 in the thickness direction of the sealing ring 30 gradually increases from the top surface 36 to the bottom surface 32. The cross-sectional width of the first transition surface 313 in the thickness direction of the sealing ring 30 gradually increases from the top surface 36 to the bottom surface 32. That is, the cross-sectional width of the sealing ring 30 in the thickness direction remains constant from the top surface 36 to the bottom surface 32, then gradually increases and then remains constant again. The outer surface 31 of the sealing ring 30 is in the shape of a semi-"C", with the opening of the "C" facing downward towards the plastic 20.

[0229] The first contact surface 211 of the lower plastic 20, away from the second contact surface 212, is connected to the fourth surface 232. The first contact surface 211 is perpendicular to the fourth surface 232 and / or the third surface 231 of the lower plastic 20. The second contact surface 212 of the lower plastic 20, away from the first contact surface 211, is connected to the third surface 231. The first contact surface 211 and the second contact surface 212 are connected by a second transition surface 213. The second transition surface 213 is arc-shaped. The cross-sectional width of the first contact surface 211 in the thickness direction of the lower plastic 20 remains constant from the fourth surface 232 to the third surface 231. The cross-sectional width of the second contact surface 212 in the thickness direction of the lower plastic 20 gradually increases from the fourth surface 232 to the third surface 231. The cross-sectional width of the second transition surface 213 in the thickness direction of the lower plastic 20 gradually increases from the fourth surface 232 to the third surface 231. That is, the cross-sectional width of the inner wall of the second through hole 21 in the thickness direction of the lower plastic 20 remains constant from the fourth surface 232 to the third surface 231 and then gradually increases. The inner wall of the second through hole 21 of the lower plastic 20 is in the shape of a semi-"C", with the opening of the "C" facing away from the sealing ring 30.

[0230] The second contact surface 212 of the lower plastic 20 is interference-fitted with the second connecting surface 312 of the sealing ring 30. A gap exists between the first contact surface 211 of the lower plastic 20 and the first connecting surface 311 of the sealing ring 30. In this embodiment, the first width W1 is equal to the second width W2.

[0231] This embodiment can block the electrolyte at the interference fit between the lower plastic 20 and the sealing ring 30, preventing the electrolyte from entering the gap between the top cover 10 and the electrode 50 and reducing the resistance of the electrode 50.

[0232] In this embodiment, the assembly process of the top cover assembly 100 may include at least the following steps:

[0233] First, install the electrode post 50 onto the lower plastic 20, so that the electrode post body 51 of the electrode post 50 passes through the second through hole 21 of the lower plastic 20, and so that the electrode post base 52 of the electrode post 50 abuts against the lower plastic 20.

[0234] Next, the sealing ring 30 is fitted onto the electrode body 51 of the electrode post 50 from above, and the second connecting surface 312 of the sealing ring 30 is pressed into the second through hole 21 of the lower plastic 20, so that the second connecting surface 312 of the sealing ring 30 abuts against the second contact surface 212 of the lower plastic 20. Then, the first connecting surface 311 of the sealing ring 30 can enter into the second through hole 21 of the lower plastic 20 under the guiding action, and the sealing ring 30 abuts against the electrode base 52 of the electrode post 50 away from the surface of the upper plastic 40.

[0235] Seventh embodiment:

[0236] Please refer to the following: Figure 23a and Figure 23b , Figure 23a It is along Figure 3 The diagram shows a seventh cross-sectional view of a portion of the structure of the top cover assembly 100 obtained by cutting along section line AA. Figure 23b yes Figure 23a Enlarged view of region Q in the middle. In this embodiment, the contents identical to those in the fifth embodiment will not be repeated. The difference from the fifth embodiment is that the second connecting surface 312 in the sealing ring 30 is parallel to the thickness direction of the sealing ring 30. The second contact surface 212 in the lower plastic 20 is parallel to the thickness direction of the lower plastic 20. That is, the second connecting surface 312 is perpendicular to the bottom surface 32 and / or top surface 36 of the sealing ring 30 (within allowable tolerance). The second contact surface 212 is perpendicular to the third surface 231 and / or fourth surface 232 of the lower plastic 20 (within allowable tolerance). Furthermore, the description of the top cover assembly 100 below can be applied to the first to sixth embodiments described above, unless otherwise specified.

[0237] It is understandable that in this embodiment, designing the second connecting surface 312 of the sealing ring 30 at a right angle relative to the bottom surface 32, and designing the second contact surface 212 of the lower plastic 20 at a right angle to the fourth surface 232, can save pressing time and improve production efficiency. Setting the other interference fit surface in the sealing ring 30 and the lower plastic 20 as an inclined surface can increase the leakage path in the top cover assembly 100.

[0238] In one possible application scenario, please continue to refer to [the relevant documentation / references]. Figure 23a and Figure 23b The first connecting surface 311 of the sealing ring 30, away from the second connecting surface 312, is spaced apart from the top surface 36 of the sealing ring 30. The second connecting surface 312 of the sealing ring 30, away from the first connecting surface 311, is connected to the bottom surface 32 of the sealing ring 30. The second connecting surface 312 is perpendicular to the bottom surface 32 and / or the top surface 36 of the sealing ring 30. The first connecting surface 311 and the second connecting surface 312 are connected by a first transition surface 313. The first transition surface 313 is arc-shaped. The cross-sectional width of the first connecting surface 311 in the thickness direction of the sealing ring 30 gradually decreases from the top surface 36 to the bottom surface 32. The cross-sectional width of the second connecting surface 312 in the thickness direction of the sealing ring 30 remains unchanged from the top surface 36 to the bottom surface 32. The cross-sectional width of the first transition surface 313 in the thickness direction of the sealing ring 30 gradually decreases from the top surface 36 to the bottom surface 32. That is, the cross-sectional width of the sealing ring 30 in the thickness direction first remains constant, then decreases, and then remains constant again from the top surface 36 to the bottom surface 32. The outer surface 31 of the sealing ring 30 is in the shape of a semi-"C", with the opening of the "C" facing the lower plastic 20.

[0239] The first contact surface 211 of the lower plastic 20, away from the second contact surface 212, is connected to the fourth surface 232. The second contact surface 212 of the lower plastic 20, away from the first contact surface 211, is connected to the third surface 231. The second contact surface 212 is perpendicular to the third surface 231 and / or the fourth surface 232 of the lower plastic 20. The first contact surface 211 and the second contact surface 212 are connected by a second transition surface 213. The second transition surface 213 is arc-shaped. The cross-sectional width of the first contact surface 211 in the thickness direction of the lower plastic 20 gradually decreases from the fourth surface 232 to the third surface 231. The cross-sectional width of the second contact surface 212 in the thickness direction of the lower plastic 20 remains unchanged from the fourth surface 232 to the third surface 231. The cross-sectional width of the second transition surface 213 in the thickness direction of the lower plastic 20 gradually decreases from the fourth surface 232 to the third surface 231. That is, the cross-sectional width of the inner wall of the second through hole 21 in the thickness direction of the lower plastic 20 first remains constant, then decreases, and then remains constant again from the fourth surface 232 to the third surface 231. The inner wall of the second through hole 21 of the lower plastic 20 is in the shape of a semi-"C", with the opening of the "C" facing away from the sealing ring 30.

[0240] The first contact surface 211 of the lower plastic 20 is interference-fitted with the first connecting surface 311 of the sealing ring 30. A gap exists between the second contact surface 212 of the lower plastic 20 and the second connecting surface 312 of the sealing ring 30. In this embodiment, the first width W1 is equal to the second width W2.

[0241] This embodiment can block the electrolyte at the interference fit between the lower plastic 20 and the sealing ring 30, thus preventing the problem of reduced resistance of the electrode post 50.

[0242] In this embodiment, the assembly process of the top cover assembly 100 may include at least the following steps:

[0243] First, install the electrode post 50 onto the lower plastic 20, so that the electrode post body 51 of the electrode post 50 passes through the second through hole 21 of the lower plastic 20, and so that the electrode post base 52 of the electrode post 50 abuts against the lower plastic 20.

[0244] Next, the sealing ring 30 is fitted onto the electrode body 51 of the electrode post 50 from above. The second connecting surface 312 of the sealing ring 30 can enter the second through hole 21 of the lower plastic 20 under the guidance of the sealing ring 30. Then, the electrode post 50 is installed on the top cover 10, so that the top cover 10 compresses the sealing ring 30, and the first connecting surface 311 of the sealing ring 30 is interference-fitted with the second contact surface 212 of the lower plastic 20, thus achieving an interference fit between the sealing ring 30 and the lower plastic 20. The surface of the sealing ring 30 facing away from the upper plastic 40 abuts against the electrode base 52 of the electrode post 50.

[0245] 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, the top cover including a first surface for facing the battery cell, the top cover having a first through hole extending through the top cover along the thickness direction; The lower plastic is connected to the first surface. The lower plastic is provided with a second through hole, which penetrates the lower plastic along the thickness direction and communicates with the first through hole. An electrode post, comprising an electrode post base and an electrode post body, wherein the electrode post base is connected to the surface of the lower plastic layer facing away from the top cover, one end of the electrode post body is connected to the electrode post base, the electrode post body passes through the first through hole and the second through hole, and the other end of the electrode post body protrudes relative to the top cover; and A sealing ring is sleeved on the pole body, a portion of the sealing ring is located in the second through hole and elastically abuts against the top cover and the pole base, and the end of the sealing ring located in the second through hole near the lower plastic is interference-fitted with the lower plastic. The sealing ring includes an outer side surface, which is the surface of the sealing ring near the lower plastic. The outer side surface is interference-fitted with the inner wall of the second through hole. The outer side surface includes a first connecting surface and a second connecting surface connected to each other. The first connecting surface is closer to the top cover than the second connecting surface. Both the first connecting surface and the second connecting surface are inclined relative to the thickness direction of the sealing ring. The inner wall of the second through hole includes a first contact surface and a second contact surface connected to each other. The first contact surface is closer to the top cover than the second contact surface. Both the first contact surface and the second contact surface are inclined relative to the thickness direction of the lower plastic. The first contact surface is interference-fitted with at least a portion of the first connecting surface, and / or the second contact surface is interference-fitted with at least a portion of the second connecting surface.

2. The top cover assembly according to claim 1, characterized in that, The sealing ring further includes a top surface and a bottom surface, which are arranged opposite to each other in the thickness direction of the sealing ring and are respectively connected to the two ends of the outer side of the sealing ring. The top surface abuts against the top cover, and the bottom surface abuts against the pole base. The cross-sectional width of the first connecting surface in the thickness direction of the sealing ring gradually increases from the top surface to the bottom surface, and the cross-sectional width of the second connecting surface in the thickness direction of the sealing ring gradually decreases from the top surface to the bottom surface. The lower plastic includes a third surface and a fourth surface. The third surface and the fourth surface are arranged opposite to each other in the thickness direction of the lower plastic and are respectively connected to both ends of the inner wall of the second through hole. The fourth surface abuts against the top cover. The cross-sectional width of the first contact surface in the thickness direction of the lower plastic gradually increases from the fourth surface to the third surface, and the cross-sectional width of the second contact surface in the thickness direction of the lower plastic gradually decreases from the fourth surface to the third surface.

3. The top cover assembly according to claim 1, characterized in that, The sealing ring further includes a top surface and a bottom surface, which are arranged opposite to each other in the thickness direction of the sealing ring and are respectively connected to the two ends of the outer side of the sealing ring. The top surface abuts against the top cover, and the bottom surface abuts against the pole base. The cross-sectional width of the first connecting surface in the thickness direction of the sealing ring gradually decreases from the top surface to the bottom surface, and the cross-sectional width of the second connecting surface in the thickness direction of the sealing ring gradually increases from the top surface to the bottom surface. The lower plastic includes a third surface and a fourth surface. The third surface and the fourth surface are arranged opposite to each other in the thickness direction of the lower plastic and are respectively connected to both ends of the inner wall of the second through hole. The fourth surface abuts against the top cover. The cross-sectional width of the first contact surface in the thickness direction of the lower plastic gradually decreases from the fourth surface to the third surface, and the cross-sectional width of the second contact surface in the thickness direction of the lower plastic gradually increases from the fourth surface to the third surface.

4. A top cover assembly, characterized in that, The top cover assembly includes: A top cover, the top cover including a first surface for facing the battery cell, the top cover having a first through hole extending through the top cover along the thickness direction; The lower plastic is connected to the first surface. The lower plastic is provided with a second through hole, which penetrates the lower plastic along the thickness direction and communicates with the first through hole. An electrode post, comprising an electrode post base and an electrode post body, wherein the electrode post base is connected to the surface of the lower plastic layer facing away from the top cover, one end of the electrode post body is connected to the electrode post base, the electrode post body passes through the first through hole and the second through hole, and the other end of the electrode post body protrudes relative to the top cover; and A sealing ring is sleeved on the pole body, a portion of the sealing ring is located in the second through hole and elastically abuts against the top cover and the pole base, and the end of the sealing ring located in the second through hole near the lower plastic is interference-fitted with the lower plastic. The sealing ring includes an outer surface, which is the surface of the sealing ring near the lower plastic. The outer surface is interference-fitted with the inner wall of the second through hole. The outer surface includes a first connecting surface and a second connecting surface connected to each other. The first connecting surface is closer to the top cover than the second connecting surface. The first connecting surface is parallel to the thickness direction of the sealing ring, and the second connecting surface is inclined relative to the thickness direction of the sealing ring. The inner wall of the second through hole includes a first contact surface and a second contact surface connected to each other. The first contact surface is closer to the top cover than the second contact surface. The first contact surface is arranged parallel to the thickness direction of the lower plastic, and the second contact surface is arranged inclined relative to the thickness direction of the lower plastic. The first contact surface is interference-fitted with at least a portion of the first connecting surface, and / or the second contact surface is interference-fitted with at least a portion of the second connecting surface.

5. The top cover assembly according to claim 4, characterized in that, The sealing ring further includes a top surface and a bottom surface, which are arranged opposite to each other in the thickness direction of the sealing ring and are respectively connected to the two ends of the outer side of the sealing ring. The top surface abuts against the top cover, and the bottom surface abuts against the pole base. The cross-sectional width of the first connecting surface in the thickness direction of the sealing ring remains unchanged from the top surface to the bottom surface, and the cross-sectional width of the second connecting surface in the thickness direction of the sealing ring gradually decreases from the top surface to the bottom surface. The lower plastic includes a third surface and a fourth surface. The third surface and the fourth surface are arranged opposite to each other in the thickness direction of the lower plastic and are respectively connected to both ends of the inner wall of the second through hole. The fourth surface abuts against the top cover. The cross-sectional width of the first contact surface in the thickness direction of the lower plastic remains unchanged from the fourth surface to the third surface. The cross-sectional width of the second contact surface in the thickness direction of the lower plastic gradually decreases from the fourth surface to the third surface.

6. The top cover assembly according to claim 4, characterized in that, The sealing ring further includes a top surface and a bottom surface, which are arranged opposite to each other in the thickness direction of the sealing ring and are respectively connected to the two ends of the outer side of the sealing ring. The top surface abuts against the top cover, and the bottom surface abuts against the pole base. The cross-sectional width of the first connecting surface in the thickness direction of the sealing ring remains unchanged from the top surface to the bottom surface, and the cross-sectional width of the second connecting surface in the thickness direction of the sealing ring gradually increases from the top surface to the bottom surface. The lower plastic includes a third surface and a fourth surface. The third surface and the fourth surface are arranged opposite to each other in the thickness direction of the lower plastic and are respectively connected to both ends of the inner wall of the second through hole. The fourth surface abuts against the top cover. The cross-sectional width of the first contact surface in the thickness direction of the lower plastic remains unchanged from the fourth surface to the third surface. The cross-sectional width of the second contact surface in the thickness direction of the lower plastic gradually increases from the fourth surface to the third surface.

7. A top cover assembly, characterized in that, The top cover assembly includes: A top cover, the top cover including a first surface for facing the battery cell, the top cover having a first through hole extending through the top cover along the thickness direction; The lower plastic is connected to the first surface. The lower plastic is provided with a second through hole, which penetrates the lower plastic along the thickness direction and communicates with the first through hole. An electrode post, comprising an electrode post base and an electrode post body, wherein the electrode post base is connected to the surface of the lower plastic layer facing away from the top cover, one end of the electrode post body is connected to the electrode post base, the electrode post body passes through the first through hole and the second through hole, and the other end of the electrode post body protrudes relative to the top cover; and A sealing ring is sleeved on the pole body, a portion of the sealing ring is located in the second through hole and elastically abuts against the top cover and the pole base, and the end of the sealing ring located in the second through hole near the lower plastic is interference-fitted with the lower plastic. The sealing ring includes an outer surface, which is the surface of the sealing ring near the lower plastic. The outer surface is interference-fitted with the inner wall of the second through hole. The outer surface includes a first connecting surface and a second connecting surface connected to each other. The first connecting surface is closer to the top cover than the second connecting surface. The first connecting surface is inclined relative to the thickness direction of the sealing ring, and the second connecting surface is parallel to the thickness direction of the sealing ring. The inner wall of the second through hole includes a first contact surface and a second contact surface connected to each other. The first contact surface is closer to the top cover than the second contact surface. The first contact surface is inclined relative to the thickness direction of the lower plastic, and the second contact surface is parallel to the thickness direction of the lower plastic. The first contact surface is interference-fitted with at least a portion of the first connecting surface, and / or the second contact surface is interference-fitted with at least a portion of the second connecting surface.

8. The top cover assembly according to claim 7, characterized in that, The sealing ring further includes a top surface and a bottom surface, which are arranged opposite to each other in the thickness direction of the sealing ring and are respectively connected to the two ends of the outer side of the sealing ring. The top surface abuts against the top cover, and the bottom surface abuts against the pole base. The cross-sectional width of the first connecting surface in the thickness direction of the sealing ring gradually increases from the top surface to the bottom surface, and the cross-sectional width of the second connecting surface in the thickness direction of the sealing ring remains unchanged from the top surface to the bottom surface. The lower plastic includes a third surface and a fourth surface. The third surface and the fourth surface are arranged opposite to each other in the thickness direction of the lower plastic and are respectively connected to both ends of the inner wall of the second through hole. The fourth surface abuts against the top cover. The cross-sectional width of the first contact surface in the thickness direction of the lower plastic gradually increases from the fourth surface to the third surface. The cross-sectional width of the second contact surface in the thickness direction of the lower plastic remains unchanged from the fourth surface to the third surface.

9. The top cover assembly according to claim 7, characterized in that, The sealing ring further includes a top surface and a bottom surface, which are arranged opposite to each other in the thickness direction of the sealing ring and are respectively connected to the two ends of the outer side of the sealing ring. The top surface abuts against the top cover, and the bottom surface abuts against the pole base. The cross-sectional width of the first connecting surface in the thickness direction of the sealing ring gradually decreases from the top surface to the bottom surface, and the cross-sectional width of the second connecting surface in the thickness direction of the sealing ring remains unchanged from the top surface to the bottom surface. The lower plastic includes a third surface and a fourth surface. The third surface and the fourth surface are arranged opposite to each other in the thickness direction of the lower plastic and are respectively connected to both ends of the inner wall of the second through hole. The fourth surface abuts against the top cover. The cross-sectional width of the first contact surface in the thickness direction of the lower plastic gradually decreases from the fourth surface to the third surface. The cross-sectional width of the second contact surface in the thickness direction of the lower plastic remains unchanged from the fourth surface to the third surface.

10. The top cover assembly according to any one of claims 1-9, characterized in that, The angle formed by the connection of the first connecting surface and the second connecting surface is the first included angle, and the angle formed by the connection of the first contact surface and the second contact surface is the second included angle, which is smaller than the first included angle.

11. The top cover assembly according to any one of claims 1-9, characterized in that, The sealing ring includes a first state and a second state; When the sealing ring is in the first state, the sealing ring is separated from the lower plastic, and the cross-sectional width of the sealing ring along the thickness direction of the sealing ring is the first width; When the sealing ring is in the second state, the sealing ring is interference-fitted with the lower plastic, and the cross-sectional width of the sealing ring along the thickness direction is the second width, which is smaller than the first width.

12. The top cover assembly according to claim 11, characterized in that, The difference between the first width and the second width is in the range of 3% to 5% of the first width.

13. The top cover assembly according to any one of claims 1-9, characterized in that, The sealing ring includes a sealing ring body and a connecting part. The sealing ring body is sleeved on the electrode body and spaced apart from the electrode body, and is interference-fitted with the lower plastic. One end of the connecting part is connected to the side of the sealing ring body away from the lower plastic, and the other end of the connecting part abuts against the electrode body.

14. The top cover assembly according to any one of claims 1-9, characterized in that, The top cover is provided with a first mounting groove, the opening of the first mounting groove is located on the first surface, and the first mounting groove is coaxially arranged and connected with the first through hole; The lower plastic includes a lower plastic body and a first protrusion. The lower plastic body is connected to the first surface. The first protrusion is fixedly connected to the surface of the lower plastic body facing the top cover and is located in the first mounting groove. The lower plastic also has a second mounting groove. The opening of the second mounting groove is located on the surface of the lower plastic body away from the top cover. The second mounting groove is coaxially arranged and connected with the second through hole. Part of the pole post base is located in the second mounting groove.

15. A battery, characterized in that, The battery includes a cell, a housing, and a top cover assembly as described in any one of claims 1-14, the top cover assembly being connected to the housing and forming an accommodating space with the housing, the cell being located within the accommodating space.

16. An electrical appliance, characterized in that, The electrical device includes the battery as described in claim 15.

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