Top cover assembly, battery and electric equipment

Abstract

The utility model provides a top cover assembly, a battery and electric equipment. A first liquid injection hole is formed in the top cover; the sealing piece is mounted in the first liquid injection hole; the lower plastic comprises a lower plastic body, a surrounding part and a convex part, the lower plastic body is provided with a second liquid injection hole communicated with the first liquid injection hole, the surrounding part is fixedly connected to the surface, deviating from the top cover, of the lower plastic body, the surrounding part is provided with a mounting groove, and the mounting groove is communicated with the second liquid injection hole and matched with the second liquid injection hole to contain part of the sealing piece; the convex part is fixedly connected to one end, far away from the lower plastic body, of the enclosure part and is positioned in the mounting groove and the sealing piece; the fastener is located in the first liquid injection hole, connected with the top cover in a sealed mode and further connected with the sealing piece in an abutting mode. The enclosure part is provided with a first air passage communicated with the outside of the lower plastic, a second air passage is formed between the convex part and the sealing piece, a third air passage is formed between the fastening piece and the sealing piece, and the first air passage, the second air passage and the third air passage are communicated in sequence. According to the technical scheme, the detection accuracy of the sealing condition of the fastener can be improved.

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] In current battery cell manufacturing processes, after electrolyte filling into the cell, a sealant is typically inserted into the filling hole to prevent electrolyte leakage. Then, a fastener is installed in the filling hole on the top cover to tighten the sealant and further enhance the sealing performance. Helium gas detection is then used to assess the seal between the fastener and the top cover. However, because the sealant is tightly connected to the filling hole, it can easily block helium from entering the cell, preventing it from reaching the sealant and thus hindering accurate identification of the fastener's sealing condition. Utility Model Content

[0003] The embodiments of this application provide a top cover assembly, a battery, and an electrical device that can improve the accuracy of fastener sealing detection, thereby improving the sealing reliability of the injection hole.

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

[0005] A top cover, wherein the top cover is provided with a first liquid injection hole, the first liquid injection hole penetrating the top cover along the thickness direction;

[0006] A sealing element is installed in the first injection hole;

[0007] The lower plastic body includes a lower plastic body, a retaining portion, and a protrusion. The lower plastic body is stacked with the top cover. The lower plastic body has a second injection hole that penetrates the lower plastic body along its thickness direction and communicates with a first injection hole. The retaining portion is fixedly connected to the surface of the lower plastic body away from the top cover and extends towards the battery cell. The retaining portion has a mounting groove that communicates with the second injection hole and cooperates with the second injection hole to accommodate part of the sealing element. The protrusion is fixedly connected to the end of the retaining portion away from the lower plastic body and extends towards the lower plastic body. The protrusion is also located inside the mounting groove and the sealing element.

[0008] Fastener, the fastener being located inside the first injection hole and sealingly connected to the top cover, the fastener abutting against the end of the seal away from the lower plastic;

[0009] The enclosure is provided with a first air passage, which is connected to the outside of the lower plastic. A second air passage is formed between the protrusion and the sealing member. A third air passage is formed between the fastener and the end of the sealing member away from the lower plastic. The first air passage, the second air passage, and the third air passage are connected in sequence.

[0010] Understandably, in related technologies, after electrolyte filling into the battery cell, helium gas is injected into the cell, and a sealant is inserted into the filling hole to seal it and prevent electrolyte leakage. Then, a fastener is installed in the filling hole on the top cover, and a sealing connection is formed between the fastener and the top cover at the filling hole to further enhance the sealing performance of the filling hole, isolating the battery cell from the external environment. Helium gas detection is then used to determine the sealing condition between the fastener and the top cover. However, to prevent the seal from falling off, the seal and the filling hole are generally interference-fitted, preventing helium gas inside the battery cell from reaching the seal of the fastener through the area between the seal and the filling hole. Therefore, even if there is leakage at the seal between the fastener and the top cover, no helium leakage will be detected. This results in unreliable helium gas detection results and an inability to accurately identify the sealing condition of the fastener.

[0011] In this embodiment, although the seal and the first injection hole are still interference-fitted, a second air channel is provided inside the seal, allowing helium gas inside the battery cell to reach the sealing connection between the fastener and the top cover through this second air channel. This enables accurate helium gas detection at the sealing connection between the fastener and the top cover. Specifically, the helium gas inside the battery cell sequentially passes through the first air channel on the lower plastic enclosure, enters the second air channel between the seal and the protrusion, and then enters the third air channel between the fastener and the end of the seal furthest from the lower plastic, ultimately reaching the sealing connection between the fastener and the top cover. If helium gas is detected at the sealing connection between the fastener and the top cover, it indicates a poor seal. If no helium gas is detected at the sealing connection, it indicates a good seal. This significantly improves the accuracy of detecting the seal between the fastener and the top cover.

[0012] In one possible implementation, the sealing element is provided with a first through hole and a first vent groove. The first through hole extends through the sealing element along its height direction. The opening of the first vent groove is located on the inner wall of the first through hole. The dimension of the first vent groove along its height direction is smaller than the height of the sealing element. The first vent groove is also connected to the third air passage.

[0013] The protrusion includes a first sub-part and a second sub-part. The first sub-part and the second sub-part are coaxially arranged and connected. The second sub-part is connected between the first sub-part and the enclosure part. The first sub-part and at least a portion of the second sub-part are located within the first through hole. The cross-sectional width of the first sub-part along the height direction of the protrusion is greater than the cross-sectional width of the second sub-part along the height direction of the protrusion. In a direction perpendicular to the height direction of the protrusion, the first sub-part and a portion of the second sub-part are arranged opposite to the first exhaust groove. A first gap is formed between the outer peripheral surface of the first sub-part and the bottom wall of the first exhaust groove. A second gap is formed between the outer peripheral surface of the second sub-part and the inner wall of the first through hole. The second gap communicates with both the first gap and the first air passage, and cooperates with the first gap to form a portion of the second air passage.

[0014] In one possible implementation, the first vent groove is disposed around the inner wall of the first through hole in the circumferential direction, and the cross-sectional width of the first vent groove in the height direction of the seal is greater than the cross-sectional width of the first sub-part in the height direction of the protrusion.

[0015] In one possible implementation, there are multiple first exhaust grooves, which are spaced apart along the circumferential direction of the first through hole and extend along the axial direction of the first through hole. The bottom wall of each first exhaust groove forms a first gap with the outer peripheral surface of the first sub-part. The inner wall of the first through hole located between two adjacent first exhaust grooves abuts against the outer peripheral surface of the first sub-part.

[0016] In one possible implementation, the seal has a first through hole and a first vent groove. The first through hole extends through the seal along its height direction, and at least a portion of the protrusion is located within the first through hole. The opening of the first vent groove is located on the inner wall of the first through hole. The first vent groove is arranged around the inner wall of the first through hole along its circumferential direction and communicates with the third air passage. The dimension of the first vent groove along the height direction of the seal is smaller than the height of the seal.

[0017] A first gap is formed between the bottom wall of the first exhaust groove and the outer peripheral surface of the protrusion. The protrusion is provided with a second exhaust groove. The opening of the second exhaust groove is located on the outer peripheral surface of the protrusion. A second gap is formed between the bottom wall of the second exhaust groove and the inner wall of the first through hole. The second gap is connected to both the first gap and the first air passage, and cooperates with the first gap to form a portion of the second air passage.

[0018] In one possible implementation, the seal includes a first surface that abuts against the fastener;

[0019] The seal is provided with a third vent groove, the opening of which is located on the first surface. The third vent groove connects the first vent groove and the outside of the seal, forming the third air passage.

[0020] In one possible implementation, the seal includes a seal body and a limiting portion. The seal body is provided with a first through hole and a first vent groove. The limiting portion is connected around the outer peripheral surface of the seal body and protrudes relative to the outer peripheral surface of the seal body. The limiting portion is interference-fitted with the inner wall of the first injection hole.

[0021] In one possible implementation, the first injection hole includes a first hole and a second hole, the first hole and the second hole are coaxially arranged and connected, the opening of the first hole away from the second hole is located on the surface of the top cover away from the lower plastic, the minimum width of the cross section of the first hole along the height direction of the first injection hole is greater than the maximum width of the cross section of the second hole along the height direction of the first injection hole, and the seal includes a first state and a second state.

[0022] When the seal is in the first state, the fastener is separated from both the seal and the top cover, the limiting part is interference-fitted to the connection between the first hole and the second hole, and the end of the protrusion away from the enclosure part is sealed to the inner wall of the first through hole.

[0023] When the seal is in the second state, the fastener is located in the first hole and abuts against the seal. The fastener is also sealed to the top cover. The limiting part is interference-fitted to the inner wall of the second hole. The protrusion forms the second air passage between itself and the inner wall of the first through hole.

[0024] In one possible implementation, when the seal is in the first state, the length of the sealing connection area between the protrusion and the inner wall of the first through hole is greater than 0.2 mm in the height direction of the protrusion.

[0025] In one possible implementation, the fastener is provided with a first groove and a fourth vent groove. The opening of the first groove and the opening of the fourth vent groove are both located on the surface of the fastener facing the seal. The fourth vent groove also penetrates the outer peripheral surface of the fastener. When the seal is in the second state, a portion of the seal is located in the first groove and abuts against the bottom wall of the first groove. The first groove connects the fourth vent groove with the third air passage.

[0026] In one possible implementation, the enclosure includes a side plate and a bottom plate. The bottom plate and the lower plastic body are spaced apart in the thickness direction of the lower plastic. The side plate is connected between the lower plastic body and the bottom plate and forms the mounting groove with the bottom plate. The protrusion is fixedly connected to the surface of the bottom plate facing the lower plastic body.

[0027] The side plate is also provided with a second through hole, which penetrates the side plate along the thickness direction. The second through hole is connected to the mounting groove and cooperates with the mounting groove to form the first air passage.

[0028] 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.

[0029] Thirdly, this application also provides an electrical device, which includes the battery described above. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the energy storage system provided in an embodiment of this application;

[0031] Figure 2 This is a schematic diagram of a battery structure provided in an embodiment of this application;

[0032] Figure 3 This is a schematic diagram of a top cover assembly provided in an embodiment of this application;

[0033] Figure 4 yes Figure 3 The exploded view of the top cover assembly is shown.

[0034] 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.

[0035] Figure 6a yes Figure 3 A schematic diagram of a structure of the top cover assembly at one angle;

[0036] Figure 6b yes Figure 6a A schematic diagram of the top cover from another angle;

[0037] Figure 7 It is along Figure 6a A cross-sectional schematic diagram of a portion of the top cover structure obtained by cutting along section line BB;

[0038] Figure 8a yes Figure 3 A schematic diagram of a structure of the lower plastic of the top cover assembly at one angle;

[0039] Figure 8b yes Figure 8a A schematic diagram of a structure of the lower plastic at another angle is shown;

[0040] Figure 9 Is it along Figure 8a A schematic cross-sectional view of the lower plastic portion structure obtained by cutting along the cutting line CC shown.

[0041] Figure 10a 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;

[0042] Figure 10b It is along Figure 10a The diagram shows a partial structure of the top cover assembly in one state during the assembly process.

[0043] Figure 11 yes Figure 3 A schematic diagram of one structure of the seal of the top cover assembly shown;

[0044] Figure 12 It is along Figure 11 A schematic cross-sectional view of the seal obtained by cutting along the cutting line DD shown.

[0045] Figure 13 yes Figure 3 A schematic diagram of one type of fastener for the top cover assembly shown;

[0046] Figure 14 yes Figure 13 A schematic diagram of a fastener from another angle;

[0047] Figure 15 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.

[0048] Figure 16 yes Figure 3 Another structural schematic diagram of the seal of the top cover assembly shown;

[0049] Figure 17 It is along Figure 16 Another cross-sectional view of the seal obtained by cutting along section line EE is shown.

[0050] Figure 18a It is along Figure 3A third cross-sectional view of a portion of the top cover assembly obtained by cutting along section line AA.

[0051] Figure 18b This is a schematic diagram of a portion of the top cover assembly shown in 18a during the assembly process;

[0052] Figure 19 yes Figure 3 Another structural schematic diagram of the lower plastic portion of the top cover assembly at one angle;

[0053] Figure 20 yes Figure 19 The diagram shows another angle of the lower plastic section's structure.

[0054] Figure 21a 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.

[0055] Figure 21b This is a schematic diagram of a portion of the top cover assembly shown in 21a during the assembly process.

[0056] Figure label:

[0057] Energy storage system 400, power conversion device 410, first user load 420, second user load 430, electrical equipment 300, battery 200, casing 210, cell 220, top cover assembly 100, top cover 10, lower plastic 20, seal 30, fastener 40, upper plastic 50, sealing ring 60, connector 70, pole post 80, explosion-proof valve 90a, explosion-proof valve protection plate 90b, filler 90c, first injection hole 11, explosion-proof hole 12, second surface 13a, third surface 13b, first hole 11a, second hole 11b, first stepped surface 11c, second groove 14, top cover body 15, first boss 16, third groove 17, first pole post hole 18, marking 19, first sub-hole 121 Second sub-hole 122, third sub-hole 123, second injection hole 21, lower plastic body 22, enclosure part 23, main body 221, connecting part 222, fourth surface 221a, fifth surface 221b, third hole 21a, fourth hole 21b, second stepped surface 21c, side plate 231, bottom plate 232, mounting groove 2321, second through hole 2322, protrusion 24, first sub-part 241, second sub-part 242, third stepped surface 243, fourth groove 25, second pole post hole 26, second boss 27, second vent groove 28, sealing body 31, limiting part 32, first through hole 33, first surface 34, first vent groove 35, third vent groove 36, fourth stepped surface 37, first groove 41, fourth The following are considered as separate parameters: vent groove 42, third pole post hole 51, fourth pole post hole 71, minimum width D1 of the cross-section of the first hole 11a along the height direction of the first injection hole 11, maximum width D2 of the cross-section of the second hole 11b along the height direction of the first injection hole 11, minimum width D3 of the cross-section of the third hole 21a along the height direction of the second injection hole 21, maximum width D4 of the cross-section of the fourth hole 21b along the height direction of the second injection hole 21, width D5 of the cross-section of the mounting groove 2321 along the height direction of the enclosure portion 23, width D6 of the cross-section of the first sub-part 241 along the height direction of the protrusion 24, width D7 of the cross-section of the second sub-part 242 along the height direction of the protrusion 24, and width of the cross-section of the first vent groove 35 along the height direction of the sealing body 31. D8, the distance between the third step surface 243 and the surface of the bottom plate 232 facing the lower plastic 20 is L1, the distance between the first surface 34 and the surface of the bottom plate 232 of the lower plastic 20 facing the lower plastic body 22 is L2, the distance between the side wall of the first exhaust groove 35 away from the first surface 34 and the first surface 34 is L3, the distance between the side wall of the first exhaust groove 35 away from the first surface 34 and the surface of the bottom plate 232 of the lower plastic 20 facing the lower plastic body 22 is L4, the distance between the side wall of the second exhaust groove 28 away from the bottom plate 232 and the surface of the bottom plate 232 facing the lower plastic 20 is L5, the first air passage S1, the second air passage S2, the third air passage S3, the first gap T1, the second gap T2, and the third gap T3. Detailed Implementation

[0058] For ease of understanding, the terminology used in the embodiments of this application will be explained first.

[0059] 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.

[0060] Multiple: refers to two or more.

[0061] 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.

[0062] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be noted that the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0063] Embodiments of this application provide a top cover assembly, a battery, and an electrical device.

[0064] 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.

[0065] Taking electrochemical energy storage as an example, the embodiments of this application provide an electrical device. The electrical device is equipped with a set of chemical batteries. It mainly uses the chemical elements in the chemical batteries as energy storage medium. The charging and discharging process is accompanied by the chemical reaction or change of the energy storage medium. Simply put, it stores the electrical energy generated by wind and solar energy in the chemical batteries. When the use of external electrical energy reaches its peak, the stored electricity is released for use, or transferred to places with a shortage of electricity for use.

[0066] Current energy storage applications are quite widespread, including generation-side energy storage, grid-side energy storage, renewable energy grid-connected energy storage, and user-side energy storage. The corresponding types of electrical equipment include:

[0067] 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.

[0068] Small and medium-sized energy storage cabinets used in commercial and industrial energy storage scenarios on the user side, and small residential energy storage boxes used in home energy storage scenarios on the user side, mainly operate under the "peak shaving and valley filling" mode. Because there are significant price differences in electricity during peak and off-peak periods based on electricity demand, users typically charge the energy storage cabinets / boxes during off-peak hours to reduce costs; then, during peak hours, they release the electricity from the devices for use, thus saving on electricity bills. Furthermore, in remote areas and regions prone to natural disasters such as earthquakes and hurricanes, the presence of household electrical appliances effectively provides users with backup power for themselves and the power grid, avoiding the inconvenience caused by frequent power outages due to disasters or other reasons.

[0069] Please see Figure 1 , Figure 1 This is a schematic diagram of the energy storage system 400 provided in an embodiment of this application. The following description will take a home energy storage scenario in user-side energy storage as an example, but it should be understood that the electrical equipment 300 is not limited to the home energy storage scenario.

[0070] 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.

[0071] 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.

[0072] Please see Figure 2 , Figure 2 This is a schematic diagram of a battery 200 provided in an embodiment of this application.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] Understandably, during the battery cell manufacturing process, after electrolyte filling, helium is injected into the cell, and a sealant is inserted into the filling hole to prevent electrolyte leakage or helium escape. Fasteners are then installed in the filling hole on the top cover to tighten the sealant, and the sealing of the filling hole is further enhanced by forming a sealed connection between the fastener and the top cover at the filling hole (e.g., welding the fastener into the filling hole of the top cover), isolating the battery cell from the external environment. Helium gas detection is then used to check for leaks at the seal between the fastener and the top cover to determine the sealing condition. However, because the sealant is tightly connected to the filling hole, it can easily block helium from entering the cell, preventing it from reaching the seal at the fastener. Therefore, even if there is a leak at the seal between the fastener and the top cover, no helium leakage will be detected. This makes the helium gas detection results unreliable and unable to accurately identify the sealing condition of the fastener.

[0077] Therefore, embodiments of this application provide a top cover assembly 100 that improves the accuracy of fastener sealing detection, thereby improving the sealing reliability of the injection hole. The structure of the top cover assembly 100 will be described in detail below through three specific embodiments.

[0078] First embodiment:

[0079] Please refer to the following: Figure 3 , Figure 4 and Figure 5 , Figure 3 This is a schematic diagram of a top cover assembly 100 provided in an embodiment of this application. Figure 4 yes Figure 3 The exploded view of the top cover assembly 100 shown is shown below. 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.

[0080] The top cover assembly 100 may include a top cover 10, a lower plastic 20, a seal 30, a fastener 40, an upper plastic 50, a sealing ring 60, a connector 70, a pole 80, an explosion-proof valve 90a, and an explosion-proof valve protection plate 90b. The top cover 10 may have a first injection hole 11 and an explosion-proof hole 12. Both the first injection hole 11 and the explosion-proof hole 12 penetrate the top cover 10 along its thickness direction (Z direction in the figure) and are spaced apart along the length direction (X direction in the figure). The lower plastic 20 is installed on one side of the top cover 10. The lower plastic 20 may have a second injection hole 21. The second injection hole 21 penetrates the lower plastic 20 along its thickness direction (Z direction in the figure) and is coaxially arranged and connected to the first injection hole 11. The seal 30 is installed in the first injection hole 11 and the second injection hole 21 and is interference-fitted to the first injection hole 11 to prevent electrolyte leakage. Fastener 40 is located inside the first injection hole 11 and is sealed to the top cover 10. It also abuts against the seal 30 to further seal the first injection hole 11 and the second injection hole 21, thus isolating the battery cell 220 from the external environment.

[0081] The upper plastic 50 is installed on the other side of the top cover 10, and portions of the upper plastic 50 and the lower plastic 20 are located on two opposing surfaces in the thickness direction of the top cover 10. The terminal post 80 is installed on the upper plastic 50, the top cover 10, and the lower plastic 20, and can serve as an electrode lead-out of the battery 200. The sealing ring 60 is sleeved on the outside of the terminal post 80 and abuts against the surface of the top cover 10 opposite to the upper plastic 50. The connector 70 is sleeved on the outside of the terminal post 80 and abuts against both the surface of the sealing ring 60 opposite to the top cover 10 and the surface of the lower plastic 20 opposite to the top cover 10. The connector 70 can be used to support the lower plastic 20 and the sealing ring 60. The connector 70 can also be electrically connected to both the terminal post 80 and the battery cell 220. The explosion-proof valve 90a and the explosion-proof valve protection plate 90b are both connected to the explosion-proof hole 12 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 protective plate 90b covers the explosion-proof valve 90a.

[0082] The assembly includes two terminals 80, one positive and one negative. The two terminals 80 are spaced apart along the length of the top cover assembly 100 (X direction in the diagram). There are also two upper plastic inserts 50. One upper plastic insert 50 is fitted onto the positive terminal, and the other upper plastic insert 50 is fitted onto the negative terminal. There are also two sealing rings 60. One sealing ring 60 is fitted onto the positive terminal, and the other sealing ring 60 is fitted onto the negative terminal. There are also two connectors 70. One connector 70 is fitted onto the positive terminal, and the other connector 70 is fitted onto the negative terminal.

[0083] The following description uses the assembly of a terminal post 80, an upper plastic piece 50, a sealing ring 60, and a connector 70 with the top cover 10 and the lower plastic piece 20 as an example to illustrate the structure of the top cover assembly 100. Unless otherwise specified, the descriptions of a terminal post 80, an upper plastic piece 50, a sealing ring 60, and a connector 70 can be applied to other terminal posts 80, upper plastic pieces 50, sealing rings 60, and connectors 70.

[0084] Please refer to the following: Figure 6a , Figure 6b and Figure 7 , 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 6a The diagram shows another structural view of the top cover 10 from another angle. Figure 7 It is along Figure 6a The diagram shows a cross-sectional view of a portion of the structure of the top cover 10 obtained by cutting along the cutting line BB.

[0085] The top cover 10 may include a top cover body 15 and a first boss 16. The top cover body 15 includes a second surface 13a and a third surface 13b. The second surface 13a and the third surface 13b are disposed opposite each other in the thickness direction (Z direction in the figure) of the top cover body 15. The second surface 13a faces away from the battery cell 220. The third surface 13b faces the battery cell 220. The first boss 16 is fixedly connected to the top cover body 15 and protrudes relative to the third surface 13b of the top cover body 15. In some other embodiments, the top cover 10 may not include the first boss 16.

[0086] For example, the first boss 16 and the top cover body 15 can be an integral structure formed by connecting them through methods such as integral molding. Alternatively, the first boss 16 and the top cover body 15 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 in detail hereafter.

[0087] The first injection hole 11 can penetrate the second surface 13a and the third surface 13b. The first injection hole 11 is used to inject electrolyte into the cell 220. The first injection hole 11 may include a first hole 11a and a second hole 11b. The first hole 11a and the second hole 11b are coaxially arranged and connected. The opening of the first hole 11a away from the second hole 11b is located on the second surface 13a. The minimum width D1 of the cross section of the first hole 11a along the height direction (Z direction in the figure) is greater than the maximum width D2 of the cross section of the second hole 11b along the height direction of the first injection hole 11. A first stepped surface 11c can be formed at the connection between the first hole 11a and the second hole 11b.

[0088] The first injection hole 11 can be located between the first boss 16 and the top cover body 15. The first hole 11a penetrates a portion of the top cover body 15 along the thickness direction of the top cover 10. The second hole 11b penetrates the first boss 16 and the remaining portion of the top cover body 15 along the thickness direction of the top cover 10. Alternatively, the first hole 11a penetrates the top cover body 15 along the thickness direction of the top cover 10, and the second hole 11b penetrates the first boss 16 along the thickness direction of the top cover 10. In this case, the first stepped surface 11c is flush with the bottom wall of the second groove 14. Alternatively, the first hole 11a penetrates the top cover body 15 and a portion of the first boss 16 along the thickness direction of the top cover 10, and the second hole 11b penetrates the remaining portion of the first boss 16 along the thickness direction of the top cover 10.

[0089] The explosion-proof hole 12 can penetrate the second surface 13a and the third surface 13b. That is, the explosion-proof hole 12 can penetrate the top cover 10 along its thickness direction. Along the length direction of the top cover 10 (X direction in the figure), the explosion-proof hole 12 is spaced apart from the first injection hole 11. The explosion-proof hole 12 may include a first sub-hole 121, a second sub-hole 122, and a third sub-hole 123. The first sub-hole 121, the second sub-hole 122, and the third sub-hole 123 are coaxially arranged and connected. The second sub-hole 122 connects the first sub-hole 121 and the third sub-hole 123. The opening of the first sub-hole 121 at the end away from the second sub-hole 122 is located on the second surface 13a. The opening of the third sub-hole 123 at the end away from the second sub-hole 122 is located on the third surface 13b. The cross-sectional width of the second sub-hole 122 along the thickness direction of the top cover 10 is smaller than the cross-sectional width of the first sub-hole 121 along the thickness direction of the top cover 10, and also smaller than the cross-sectional width of the third sub-hole 123 along the thickness direction of the top cover 10. The first sub-hole 121 is used to accommodate and connect to the explosion-proof valve protection plate 90b. The third sub-hole 123 is used to accommodate and connect to the explosion-proof valve 90a. The shape of the explosion-proof hole 12 can be adapted to the shape of the explosion-proof valve protection plate 90b and the explosion-proof valve 90a. For example, the explosion-proof hole 12 can be elliptical or square.

[0090] The top cover 10 may be provided with a second groove 14. The opening of the second groove 14 is located on the third surface 13b. The second groove 14 may be recessed from the third surface 13b into the interior of the top cover 10. The second groove 14 is coaxially arranged with the first injection hole 11. Exemplarily, the second groove 14 may be located on the top cover body 15.

[0091] The top cover 10 may also be provided with a first electrode post hole 18 and a third groove 17. The first electrode post hole 18 can penetrate through the second surface 13a and the third surface 13b. That is, the first electrode post hole 18 can penetrate the top cover 10 along the thickness direction of the top cover 10. The first electrode post hole 18, the first injection hole 11, and the explosion-proof hole 12 are all spaced apart in the length direction of the top cover 10. The opening of the third groove 17 is located on the third surface 13b. The third groove 17 can be formed by recessing from the third surface 13b into the interior of the top cover 10. The third groove 17 is coaxially arranged and connected with the first electrode post hole 18, and is spaced apart from the second groove 14 in the length direction of the top cover 10. Exemplarily, the first electrode post hole 18 and the third groove 17 can be located on the top cover body 15.

[0092] The number of first pole post holes 18 can be two, and the two first pole post holes 18 can be spaced apart along the length of the top cover 10. The number of third grooves 17 can be two, and the two third grooves 17 are spaced apart along the length of the top cover 10, and are coaxially arranged with and connected to the two first pole post holes 18 respectively.

[0093] Please continue to refer to the following: Figure 6a and Figure 6b The top cover 10 may also be provided with a mark 19. The mark 19 is adjacent to and spaced apart from the first pole hole 18. The mark 19 is used to mark the polarity of the pole 80 installed in the first pole hole 18 of the top cover 10, so as to more efficiently align the first pole hole 18 with the positive pole 80 or the negative pole 80, and help the pole 80 of the corresponding polarity to be installed in the corresponding first pole hole 18.

[0094] For example, the identifier 19 may be located on the top cover body 15. There may be two identifiers 19. The two identifiers 19 are respectively adjacent to and spaced apart from the two first electrode holes 18. A "+" shaped identifier 19 is provided around the first electrode hole 18 connected to the positive electrode. A "-" shaped identifier 19 is provided around the first electrode hole 18 connected to the negative electrode.

[0095] Please refer to the following: Figure 8a , Figure 8b and Figure 9 , Figure 8a yes Figure 3 The diagram shows a structural schematic of the lower plastic 20 of the top cover assembly 100 at an angle. Figure 8b yes Figure 8a The diagram shows another structural representation of the lower plastic 20 from another angle. Figure 9 It is along Figure 8a The diagram shows a cross-sectional view of the lower plastic 20 structure obtained by cutting along the cutting line CC.

[0096] The lower plastic 20 and the top cover 10 are stacked together. The lower plastic 20 may include a lower plastic body 22, a retaining portion 23, and a protrusion 24.

[0097] Specifically, the lower plastic body 22 may include a main body 221 and a connecting portion 222. The main body 221 may include a fourth surface 221a and a fifth surface 221b. The fourth surface 221a and the fifth surface 221b are arranged opposite to each other in the thickness direction (Z direction in the figure). The fourth surface 221a faces away from the battery cell 220 and contacts the third surface 13b of the top cover 10. The fifth surface 221b faces the battery cell 220. The connecting portion 222 is fixedly connected to the main body 221 and protrudes relative to the fifth surface 221b of the main body 221. The connecting portion 222 and the main body 221 can be connected to form an integral structure.

[0098] The lower plastic body 22 may be provided with the second injection hole 21 described above. The second injection hole 21 may penetrate the connecting portion 222 and the main body 221 along the thickness direction of the lower plastic body 22. The second injection hole 21 is used to inject electrolyte into the battery cell 220. The second injection hole 21 may include a third hole 21a and a fourth hole 21b (in Figure 9 A dashed line is drawn to help illustrate the fourth hole 21b. The third hole 21a and the fourth hole 21b are coaxially aligned and connected. The opening of the third hole 21a away from the fourth hole 21b is located on the fourth surface 221a. The minimum width D3 of the cross-section of the third hole 21a along the height direction of the second injection hole 21 (Z direction in the diagram) is greater than the maximum width D4 of the cross-section of the fourth hole 21b along the height direction of the second injection hole 21. A second stepped surface 21c is formed between the third hole 21a and the fourth hole 21b.

[0099] In this configuration, the third hole 21a penetrates a portion of the main body 221 along the thickness direction of the lower plastic body 22. The fourth hole 21b penetrates the connecting portion 222 and the remaining portion of the main body 221 along the thickness direction of the lower plastic body 22. Alternatively, the third hole 21a penetrates the main body 221 along the thickness direction of the lower plastic body 22, and the fourth hole 21b penetrates the connecting portion 222 along the thickness direction of the lower plastic body 22. In this case, the second step surface 21c is flush with the fifth surface 221b. Alternatively, the third hole 21a penetrates the main body 221 and a portion of the connecting portion 222 along the thickness direction of the lower plastic body 22, and the fourth hole 21b penetrates the remaining connecting portion 222 along the thickness direction of the lower plastic body 22. Furthermore, the third hole 21a can also be used to accommodate the first boss 16 of the top cover 10, facilitating alignment and connection between the lower plastic 20 and the top cover 10, thereby improving the assembly efficiency of the top cover assembly 100 and the battery 200.

[0100] The enclosure portion 23 is fixedly connected to the surface of the lower plastic body 22 facing away from the top cover 10. Specifically, the enclosure portion 23 is fixedly connected to the surface of the connecting portion 222 facing away from the main body 221. The enclosure portion 23 can extend from the connecting portion 222 towards the battery cell 220. The enclosure portion 23, the connecting portion 222, and the main body 221 can be connected to form an integral structure. The enclosure portion 23 may be provided with a first air passage S1. The first air passage S1 communicates with the outside of the lower plastic 20. The first air passage S1 can be used to allow gas to pass through.

[0101] The enclosure portion 23 may include a side plate 231 and a bottom plate 232. The bottom plate 232 and the lower plastic body 22 are spaced apart in the thickness direction of the lower plastic 20. The bottom plate 232 may be arranged substantially parallel to the lower plastic body 22. The side plate 231 is connected between the bottom plate 232 and the connecting portion 222 of the lower plastic body 22. Specifically, the side plate 231 surrounds the outer edge of the fourth hole 21b of the second injection hole 21. The side plate 231 and the bottom plate 232 form a mounting groove 2321. The mounting groove 2321 is coaxially arranged with and connected to both the fourth hole 21b and the third hole 21a of the second injection hole 21. The cross-sectional width D5 of the mounting groove 2321 along the height direction (Z direction in the figure) of the enclosure portion 23 may be equal to the maximum cross-sectional width D4 of the fourth hole 21b of the second injection hole 21 along the height direction of the second injection hole 21.

[0102] In some other embodiments, the cross-sectional width D5 of the mounting groove 2321 along the height direction of the enclosure portion 23 may also be greater than the maximum cross-sectional width D4 of the fourth hole 21b of the second injection hole 21 along the height direction of the second injection hole 21. Alternatively, the cross-sectional width D5 of the mounting groove 2321 along the height direction of the enclosure portion 23 may also be less than the maximum cross-sectional width D4 of the fourth hole 21b of the second injection hole 21 along the height direction of the second injection hole 21. There is no limitation in this regard.

[0103] The side plate 231 may also be provided with a second through hole 2322. The second through hole 2322 extends through the side plate 231 along its thickness direction (the direction on the XY plane in the figure). The second through hole 2322 connects the mounting groove 2321 with the outside of the lower plastic 20. The second through hole 2322 and the mounting groove 2321 cooperate to form the first air passage S1 described above. The number of second through holes 2322 can be one or more. When there are multiple second through holes 2322, the multiple second through holes 2322 can be spaced apart along the circumferential direction of the side plate 231, and all can connect the mounting groove 2321 with the outside of the lower plastic 20. The circumferential direction of the side plate 231 is the direction surrounding the central axis of the side plate 231.

[0104] For one possible application scenario, please refer to [link / reference]. Figure 8bThere can be two second through holes 2322. The two second through holes 2322 are arranged opposite each other in a direction perpendicular to the height of the side plate 231, and both connect the mounting groove 2321 to the outside of the lower plastic 20.

[0105] Understandably, by providing a baffle 23 and a first air passage S1 on the lower plastic 20, not only can gas pass through the battery cell 220, but the first air passage S1 of the baffle 23 can also change the flow direction of the electrolyte when injecting electrolyte into the battery cell 220. That is, the multiple second through holes 2322 that make up the first air passage S1 can divide the electrolyte into multiple bundles, allowing it to enter the battery cell 220 in different directions, thereby greatly reducing the obstruction of the battery cell 220's inner wall to the electrolyte and increasing the electrolyte injection speed.

[0106] In this embodiment, please continue to refer to the following: Figure 8a , Figure 8b and Figure 9 The protrusion 24 is located within the mounting groove 2321 of the enclosure portion 23 and is fixedly connected to the bottom wall of the mounting groove 2321. That is, the protrusion 24 is fixedly connected to the surface of the base plate 232 facing the lower plastic body 22 and extends from the base plate 232 towards the lower plastic body 22. The protrusion 24 may also be located within the second hole 11b of the second injection hole 21 and the first injection hole 11. The protrusion 24 and the lower plastic body 22 can be connected to form an integral structure.

[0107] The protrusion 24 may include a first sub-part 241 and a second sub-part 242. The first sub-part 241 and the second sub-part 242 are coaxially arranged and connected. The second sub-part 242 is connected between the first sub-part 241 and the base plate 232. The cross-sectional width D6 of the first sub-part 241 along the height direction of the protrusion 24 (Z direction in the figure) is greater than the cross-sectional width D7 of the second sub-part 242 along the height direction of the protrusion 24. A third stepped surface 243 is formed at the connection between the first sub-part 241 and the second sub-part 242.

[0108] In this embodiment, to facilitate the assembly of the protrusion 24, the corner of the first sub-part 241 near the fourth surface 221a can be designed as a chamfer.

[0109] Please refer to the following: Figure 5 , Figure 8a and Figure 8b The lower plastic body 20 may also include a second protrusion 27. The second protrusion 27 is fixedly connected to the lower plastic body 22 and protrudes relative to the fourth surface 221a. The second protrusion 27 and the lower plastic body 22 can be an integral structure. The second protrusion 27 is located in the third groove 17 of the top cover 10. The surface of the second protrusion 27 facing away from the lower plastic body 22 abuts against the bottom wall of the third groove 17.

[0110] Understandably, by mounting the second protrusion 27 of the lower plastic 20 into the third groove 17 of the top cover 10, it can help align and connect the lower plastic 20 and the top cover 10, thereby improving the assembly efficiency of the top cover assembly 100 and the battery 200.

[0111] The number of second protrusions 27 can be two, and the two second protrusions 27 are spaced apart along the length of the lower plastic body 22. Each second protrusion 27 is located within a third groove 17 of a top cover 10.

[0112] Please refer to section 5 for further details. Figure 8a and Figure 8b The lower plastic 20 may have a second pole hole 26 and a fourth groove 25. The second pole hole 26 may penetrate the lower plastic body 22 and the second boss 27 along the thickness direction of the lower plastic 20. The second pole hole 26 is coaxially arranged and connected with the first pole hole 18 of the top cover 10. The inner peripheral surface of the second pole hole 26 may be spaced apart from the outer peripheral surface of the sealing ring 60. The inner peripheral surface of the second pole hole 26 is the inner surface surrounding the central axis of the second pole hole 26. The outer peripheral surface of the sealing ring 60 is the outer surface surrounding the central axis of the sealing ring 60. The opening of the fourth groove 25 is located on the fifth surface 221b. The fourth groove 25 may be formed by recessing into the lower plastic 20 from the fifth surface 221b. The fourth groove 25 is coaxially arranged and connected with the second pole hole 26.

[0113] The number of second electrode post holes 26 can be two. The two second electrode post holes 26 can be spaced apart along the length direction (X direction in the diagram) of the lower plastic 20. The number of fourth grooves 25 can also be two, and the two fourth grooves 25 are spaced apart along the length direction of the lower plastic 20. The two fourth grooves 25 are coaxially arranged with and connected to the two second electrode post holes 26.

[0114] Please refer to the following: Figure 10a and Figure 10b , Figure 10a 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 10b It is along Figure 10a This diagram illustrates a partial structure of the top cover assembly 100 during the assembly process. Figure 10a In the middle, the bolded dashed line represents the gas passage of the top cover assembly 100.

[0115] Understandably, before performing helium gas testing on the sealing condition of fastener 40, to prevent helium leakage, the first injection hole 11 and the second injection hole 21 need to be temporarily sealed by the sealing element 30 during the manufacturing process to isolate the battery cell 220 from the external environment. Subsequently, when performing helium gas testing on the sealing condition of fastener 40, to avoid affecting the accuracy of the test results, the temporary seal of the sealing element 30 on the first injection hole 11 and the second injection hole 21 needs to be removed.

[0116] Therefore, in this embodiment, the seal 30 may include a first state and a second state. When the seal 30 is in the first state (e.g., Figure 10b As shown), the first injection hole 11 of the top cover 10 is not connected to the inside of the battery cell 220. At this time, the helium gas inside the battery cell 220 cannot reach the sealing connection between the fastener 40 and the top cover 10. When the seal 30 is in the second state (e.g....), Figure 10a As shown), a gas channel (at least including the first gas channel S1 of the lower plastic 20) is formed inside the top cover assembly 100. At this time, the first liquid injection hole 11 of the top cover 10 is connected to the inside of the battery cell 220. The helium inside the battery cell 220 can reach the sealing connection between the fastener 40 and the top cover 10 through the gas channel.

[0117] Please refer to the following: Figure 10a , Figure 10b , Figure 11 and Figure 12 , Figure 11 yes Figure 3 A schematic diagram of a structure of the seal 30 of the top cover assembly 100 shown. Figure 12 It is along Figure 11 The diagram shows a cross-sectional view of the seal 30 obtained by cutting along the cutting line DD.

[0118] The seal 30 is installed on the top cover 10 and the lower plastic 20, and is located within the first injection hole 11 of the top cover 10 and the second injection hole 21 of the lower plastic 20, and is interference-fitted with the first injection hole 11. Specifically, the seal 30 may include a seal body 31 and a limiting portion 32. The limiting portion 32 is connected around the outer peripheral surface of the seal body 31 and protrudes relative to the outer peripheral surface of the seal body 31. The outer peripheral surface of the seal body 31 is the outer surface surrounding the central axis of the seal body 31. The limiting portion 32 and the seal body 31 can be connected to form an integral structure. Exemplarily, the seal 30 may be made of plastic.

[0119] When the seal 30 is in the first state, the surface of the limiting part 32 facing the cell 220 abuts against the first stepped surface 11c inside the first injection hole 11. When the seal 30 is in the second state, the limiting part 32 is located inside the second hole 11b of the first injection hole 11 and is interference-fitted with the inner wall of the second hole 11b.

[0120] Understandably, after the electrolyte is injected into the cell 220, the first injection hole 11 and the second injection hole 21 need to be sealed by the sealing member 30. However, at this time, the cell 220 is under negative pressure, and the sealing member 30 is easily dropped into the cell 220 due to the air pressure, affecting the sealing effect of the first injection hole 11 and the second injection hole 21. Therefore, this embodiment provides a limiting part 32 on the sealing member 30 and makes the limiting part 32 interference fit with the inner wall of the first injection hole 11. This not only prevents the sealing member 30 from falling off, but also saves the interference fit area between the sealing member 30 and the first injection hole 11, thereby saving the material of the sealing member 30 and saving production costs.

[0121] The seal 30 is also located within the mounting groove 2321 of the lower plastic 20 and is fitted onto the protrusion 24 of the lower plastic 20. Specifically, the seal body 31 may have a first through hole 33. The first through hole 33 extends through the seal body 31 along its height direction (Z direction in the figure). The first through hole 33 is used to accommodate the first sub-part 241 and at least a portion of the second sub-part 242 of the protrusion 24. A second gap T2 is formed between the inner wall of the first through hole 33 and the outer peripheral surface of the second sub-part 242. The second gap T2 communicates with the first air passage S1 of the lower plastic 20. The outer peripheral surface of the first sub-part 241 is the outer surface surrounding the central axis of the first sub-part 241. The outer peripheral surface of the second sub-part 242 is the outer surface surrounding the central axis of the second sub-part 242.

[0122] When the seal 30 is in the first state, a sealed connection is formed between the inner wall of the first through hole 33 and the outer peripheral surface of the first sub-part 241 to prevent helium gas in the battery cell 220 from leaking out due to the gas pressure inside the battery cell 220. When the seal 30 is in the second state, a second air passage S2 is formed between the seal 30 and the first sub-part 241 and the second sub-part 242 of the protrusion 24. The second air passage S2 is connected to the first air passage S1 of the lower plastic 20 and is used to allow gas to pass through the battery cell 220.

[0123] It is understandable that during prolonged use of the battery 200, the seal 30 is more likely to detach due to electrolyte corrosion or changes in internal pressure of the cell 220, especially when the seal 30 is not sufficiently pressurized against the inner wall of the first injection hole 11, making it easier for the seal 30 to fall into the cell 220. In this embodiment, by placing the seal 30 within the mounting groove 2321 in the enclosure portion 23 and fitting it onto the protrusion 24, the protrusion 24 and the bottom plate 232 in the enclosure portion 23 can act as a stop for the seal 30, thereby preventing it from falling into the cell 220. Furthermore, the inner wall of the first through hole 33 inside the seal 30 abuts against part of the protrusion 24, and the outer peripheral surface of the seal 30 is pressurized against the first injection hole 11, causing both the inside and outside of the seal 30 to be compressed, further reducing the risk of detachment.

[0124] Please refer to the following: Figure 10a , Figure 10b , Figure 11 and Figure 12 The sealing body 31 may include a first surface 34. The first surface 34 is the surface of the sealing body 31 that faces away from the lower plastic 20.

[0125] The sealing body 31 may be provided with a first vent groove 35. The opening of the first vent groove 35 is located on the inner wall of the first through hole 33. The first vent groove 35 may be formed by recessing from the inner wall of the first through hole 33 into the interior of the sealing body 31. The first vent groove 35 extends along the axial direction of the first through hole 33 and penetrates the first surface 34, and is spaced apart from the surface of the sealing body 31 facing the battery cell 220. That is, the dimension of the first vent groove 35 along the height direction of the sealing body 31 is smaller than the height of the sealing body 31.

[0126] The number of first exhaust grooves 35 can be one or more. When there are multiple first exhaust grooves 35, the multiple first exhaust grooves 35 are spaced apart along the circumferential direction of the first through hole 33. The circumferential direction of the first through hole 33 is the direction surrounding the central axis of the first through hole 33. For example, as shown... Figure 11 As shown, there are four first exhaust grooves 35. The four first exhaust grooves 35 are spaced apart along the circumferential direction of the first through hole 33 and are located at four equal points on the inner wall of the first through hole 33.

[0127] like Figure 10bAs shown, when the seal 30 is in the first state, the first vent groove 35 is positioned opposite to a portion of the first sub-part 241 of the protrusion 24 in a direction perpendicular to the height direction of the seal 30 (Z direction in the figure). At this time, the first vent groove 35 is isolated from the second gap T2. The distance L3 between the sidewall of the first vent groove 35 away from the first surface 34 and the first surface 34, and the distance L4 between the sidewall of the first vent groove 35 away from the first surface 34 and the surface of the bottom plate 232 of the lower plastic 20 facing the lower plastic body 22, satisfy the relationship: L3 + L4 = L2.

[0128] The distance L4 between the sidewall of the first vent groove 35 away from the first surface 34 and the surface of the bottom plate 232 of the lower plastic 20 facing the lower plastic body 22, and the distance L1 between the third step surface 243 of the protrusion 24 and the surface of the bottom plate 232 facing the lower plastic 20, satisfy the relationship: L4-L1>0.2mm. That is, in the height direction of the seal 30, the length of the sealing connection area between the inner wall of the first through hole 33 and the first sub-part 241 is greater than 0.2mm. By keeping the length of the sealing connection area between the inner wall of the first through hole 33 and the first sub-part 241 within the above range, it can be ensured that there is good sealing performance between the seal 30 and the protrusion 24 of the lower plastic 20 before helium gas detection.

[0129] like Figure 10a As shown, when the seal 30 is in the second state, the same content as when the seal 30 is in the first state will not be repeated. The difference is that, in the direction perpendicular to the height direction of the seal 30, the first exhaust groove 35 is disposed opposite to all the first sub-parts 241 of the protrusion 24, and also opposite to a portion of the second sub-parts 242 of the protrusion 24. A first gap T1 is formed between the bottom wall of the first exhaust groove 35 and the outer peripheral surface of the first sub-parts 241 of the protrusion 24. A third gap T3 is formed between the bottom wall of the first exhaust groove 35 and the outer peripheral surface of the second sub-parts 242 of the protrusion 24. The third gap T3 connects the first gap T1 and the second gap T2. The first air passage S1, the second gap T2, the third gap T3 and the first gap T1 are sequentially connected. Among them, the first gap T1, the second gap T2, the third gap T3 and the first through hole 33 cooperate to form the second air passage S2 described above.

[0130] Furthermore, the distance L3 between the sidewall of the first exhaust groove 35 away from the first surface 34 and the first surface 34 coincides with the distance L1 between the third step surface 243 of the protrusion 24 and the surface of the bottom plate 232 facing downward plastic 20, and satisfies the relationship: L3+L1>L2.

[0131] Furthermore, when there are multiple first exhaust grooves 35, a first gap T1 is formed between the bottom wall of each first exhaust groove 35 and the outer peripheral surface of the first sub-part 241. A third gap T3 is formed between the bottom wall of each first exhaust groove 35 and the outer peripheral surface of the second sub-part 242. The inner wall of the first through hole 33 located between two adjacent first exhaust grooves 35 abuts against the outer peripheral surface of the first sub-part 241.

[0132] In this embodiment, please continue to refer to the following: Figure 10a , Figure 11 and Figure 12 The sealing body 31 may be provided with a third vent groove 36. The opening of the third vent groove 36 is located on the first surface 34. The third vent groove 36 may be formed by recessing from the first surface 34 into the interior of the sealing body 31. The third vent groove 36 connects the first vent groove 35 and the exterior of the sealing body 31. That is, the third vent groove 36 penetrates the bottom wall of the first vent groove 35 and the outer peripheral surface of the sealing body 31.

[0133] The number of third exhaust grooves 36 is equal to the number of first exhaust grooves 35. That is, there can be one or more third exhaust grooves 36. When there are multiple third exhaust grooves 36, the multiple third exhaust grooves are spaced apart along the circumferential direction of the first through hole 33. Each third exhaust groove 36 is connected to one first exhaust groove 35.

[0134] For example, such as Figure 11 As shown, there can be four third exhaust grooves 36. The four third exhaust grooves 36 are spaced apart along the circumferential direction of the first through hole 33 and are located at four equal points on the outer edge of the first through hole 33. Each third exhaust groove 36 is connected to a first exhaust groove 35.

[0135] In this embodiment, please refer to the relevant documentation. Figure 10a , Figure 10b , Figure 13 and Figure 14 , Figure 13 yes Figure 3 A schematic diagram of one structure of the fastener 40 of the top cover assembly 100 shown. Figure 14 yes Figure 13 A structural schematic diagram of the fastener 40 from another angle.

[0136] When the seal 30 is in the first state, the fastener 40 is separated from both the seal 30 and the top cover 10.

[0137] When the seal 30 is in the second state, the fastener 40 is located within the first hole 11a of the first injection hole 11 and abuts against the inner wall of the first hole 11a. That is, the fastener 40 abuts against the first stepped surface 11c within the first injection hole 11. The fastener 40 is also sealed to the top cover 10. Specifically, the outer peripheral surface of the fastener 40 forms a sealed connection with the inner wall of the first hole 11a to isolate the battery cell 220 from the external environment. The outer peripheral surface of the fastener 40 is a surface surrounding the central axis of the fastener 40. Exemplarily, the fastener 40 can be welded to the top cover 10. The fastener 40 also abuts against the first surface 34 of the seal 30 and forms a third vent S3 between itself and the end of the seal 30 away from the lower plastic 20. Specifically, the third vent groove 36 of the seal 30 forms the third vent S3. The third air passage S3 is connected to the first air passage S1 via the second air passage S2, and together they form a channel for the gas inside the battery cell 220 to reach the sealed connection of the fastener 40. The third air passage S3 is connected to the first exhaust groove 35 of the seal 30.

[0138] In this embodiment, the fastener 40 may be provided with a first groove 41 and a fourth venting groove 42. The opening of the first groove 41 is located on the surface of the fastener 40 facing the seal 30. The first groove 41 is formed by recessing from the surface of the fastener 40 facing the seal 30 into the interior of the fastener 40. The first groove 41 is used to accommodate part of the seal 30. When the seal 30 is in the second state, the bottom wall of the first groove 41 abuts against the seal 30 and is spaced apart from the bottom wall of the third venting groove 36 of the seal 30.

[0139] The opening of the fourth vent groove 42 is located on the surface of the fastener 40 facing the seal 30. The fourth vent groove 42 communicates with the first groove 41 and is formed by recessing from the surface of the fastener 40 facing the seal 30 into the fastener 40. The fourth vent groove 42 also penetrates the outer peripheral surface of the fastener 40 and the sidewall of the first groove 41. When the seal 30 is in the second state, the fourth vent groove 42 communicates with the third air passage S3 (i.e., the third vent groove 36 of the seal 30) through the first groove 41. The depth of the fourth vent groove 42 (the dimension in the Z direction shown in the figure) can be less than the depth of the first groove 41 (the dimension in the Z direction shown in the figure).

[0140] In some other embodiments, the depth of the fourth vent groove 42 may be equal to the depth of the first groove 41. Alternatively, the depth of the fourth vent groove 42 may be greater than the depth of the first groove 41. There is no limitation in this regard.

[0141] The number of fourth exhaust grooves 42 can be one or more. When there are multiple fourth exhaust grooves, the multiple fourth exhaust grooves 42 are spaced apart along the circumferential direction of the first groove 41. The circumferential direction of the first groove 41 is the direction around the axis of the first groove 41. Each fourth exhaust groove 42 is connected to the first groove 41.

[0142] For example, such as Figure 14 As shown, there can be four fourth exhaust grooves 42. The four fourth exhaust grooves 42 are spaced apart along the circumferential direction of the first groove 41 and are located at four equal points on the outer edge of the first groove 41. Each fourth exhaust groove 42 is connected to the first groove 41.

[0143] Understandably, when installing the fastener 40, a cylinder is needed to press the fastener 40 down, so that the fastener 40 applies a force to the seal 30 in the direction of the cell 220, thereby pushing the seal 30 downward and realizing the transition of the seal 30 from the first state to the second state. However, since the fastener 40 needs to overcome the frictional resistance between the seal 30 and the protrusion 24 of the lower plastic 20 and the top cover 10 to move the seal 30 downward, the force exerted by the cylinder on the fastener 40 will be relatively large. This may result in a large force between the fastener 40 and the first step surface 11c in the first injection hole 11 of the top cover 10, which may easily cause a false seal to be formed between the fastener 40 and the first step surface 11c. As a result, during helium detection, the helium is blocked in the first groove 41 of the fastener 40 and cannot reach the seal between the fastener 40 and the top cover 10, thus leading to inaccurate detection results. Therefore, in this embodiment, by providing a fourth venting groove 42 on the fastener 40, a channel can be provided for helium to pass through, ensuring that the helium can reach the seal between the fastener 40 and the top cover 10, thereby improving the accuracy and reliability of the test results.

[0144] In related technologies, after electrolyte filling into the battery cell is completed, a sealant and fastener are placed inside the filling hole to seal it and prevent electrolyte leakage. The sealing performance of the filling hole is further enhanced by forming a sealed connection between the fastener and the top cover, isolating the battery cell from the external environment. Helium gas detection is then used to determine the sealing condition between the fastener and the top cover. However, to prevent the seal from falling off, the seal and the filling hole are generally interference-fitted. This prevents the helium gas inside the battery cell from reaching the seal of the fastener through the area between the seal and the filling hole, thus making it impossible to accurately identify the sealing condition of the fastener.

[0145] In this embodiment, although the seal 30 and the first injection hole 11 are still interference-fitted, by providing a second air passage S2 inside the seal 30, the helium in the cell 220 can reach the sealing connection between the fastener 40 and the top cover 10 through the second air passage S2 inside the seal 30, thereby enabling accurate helium detection at the sealing connection between the fastener 40 and the top cover 10. Specifically, as... Figure 10aAs shown, the helium gas inside the battery cell 220 sequentially passes through the first gas channel S1 of the lower plastic 20 (i.e., sequentially through the second through hole 2322 and the mounting groove 2321 of the enclosure portion 23 of the lower plastic 20), enters the second gas channel S2 (i.e., sequentially through the second gap T2, the third gap T3 and the first gap T1 between the seal 30 and the protrusion 24 of the lower plastic 20, and then diffuses to the first through hole 33 of the seal 30), and then enters the third gas channel S3 (the third exhaust groove 36 of the seal 30) from the second gas channel S2. Subsequently, it sequentially passes through the first groove 41 and the fourth exhaust groove 42 of the fastener 40 to reach the sealing connection between the outer peripheral surface of the fastener 40 and the top cover 10. At this time, if helium gas is detected at the sealing connection between the fastener 40 and the top cover 10, it indicates that the sealing connection between the fastener 40 and the top cover 10 is poor. If no helium is detected at the sealed connection between fastener 40 and top cover 10, it indicates that the seal between fastener 40 and top cover 10 is good. This greatly improves the accuracy of detecting the seal between fastener 40 and top cover 10.

[0146] In this embodiment, the assembly of the top cover assembly 100 may include at least the following steps:

[0147] Step 1: Assemble the top cover 10 and the lower plastic 20 such that the first protrusion 16 of the top cover 10 is located inside the second injection hole 21 of the lower plastic 20.

[0148] Step 2: Insert the sealing member 30 into the first injection hole 11 of the top cover 10 and the second injection hole 21 of the lower plastic 20, and press down on the sealing member 30 so that it fits onto the protrusion 24 of the lower plastic 20, until the limiting part 32 of the sealing member 30 contacts the first step surface 11c inside the first injection hole 11, then stop pressing down (e.g., Figure 10b (As shown).

[0149] Step 3: Place the fastener 40 into the first injection hole 11 of the top cover 10, and use a cylinder to press the fastener 40 down, so that the fastener 40 presses against the first surface 34 of the seal 30, and applies a force to the seal 30 in the direction of the cell 220, thereby pushing the seal 30 downward accordingly (e.g., Figure 10a (as shown), until the fastener 40 abuts against the first stepped surface 11c inside the first injection hole 11.

[0150] Step 4: Secure the fastener 40 to the top cover 10, and make the fastener 40 and the top cover 10 form a sealing relationship.

[0151] Please see Figure 5The upper plastic 50 is connected to the second surface 13a of the top cover 10. A portion of the upper plastic 50 is also located within the first electrode hole 18 and the second electrode hole 26 of the top cover 10. The upper plastic 50 serves as insulation and separates the electrode 80 from the top cover 10, preventing direct contact between the top cover 10 and the electrode 80 and thus preventing a short circuit. The upper plastic 50 may have a third electrode hole 51. The third electrode hole 51 extends through the upper plastic 50 along its thickness direction (Z direction in the diagram). The third electrode hole 51 communicates with the first electrode hole 18 of the top cover 10 and the second electrode hole 26 of the lower plastic 20.

[0152] The connector 70 is located within the fourth groove 25 of the lower plastic 20 and abuts against the bottom wall of the fourth groove 25. The connector 70 protrudes relative to the fifth surface 221b of the lower plastic 20. The connector 70 may have a fourth post hole 71. The fourth post hole 71 penetrates the connector 70 along its thickness direction (Z direction in the figure). The fourth post hole 71 communicates with the third post hole 51 of the upper plastic 50.

[0153] For one possible implementation, please refer to [link / reference needed]. Figure 5 The electrode post 80 passes sequentially through the third electrode post hole 51 of the upper plastic 50, the first electrode post hole 18 of the top cover 10, the second electrode post hole 26 of the lower plastic 20, the sealing ring 60, and the fourth electrode post hole 71 of the connector 70. In the height direction of the electrode post 80, both ends of the electrode post 80 protrude relative to the upper plastic 50 and the connector 70, respectively.

[0154] For another possible implementation, please refer to Figure 15 , Figure 15 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. The top cover assembly 100 may further include a filler 90c. The filler 90c is located between the terminal post 80 and the upper plastic 50, and between the terminal post 80 and the connector 70. The filler 90c passes through the third terminal post hole 51 of the upper plastic 50 and the fourth terminal post hole 71 of the connector 70, and protrudes relative to the connector 70. The terminal post 80 sequentially passes through the third terminal post hole 51 of the upper plastic 50, the first terminal post hole 18 of the top cover 10, the second terminal post hole 26 of the lower plastic 20, the sealing ring 60, and the fourth terminal post hole 71 of the connector 70. The end of the terminal post 80 furthest from the battery cell 220 protrudes relative to the upper plastic 50.

[0155] Second embodiment:

[0156] Please see Figure 8a , Figure 16 and Figure 17 , Figure 16 yes Figure 3Another structural schematic diagram of the seal 30 of the top cover assembly 100 shown. Figure 17 It is along Figure 16 Another cross-sectional view of the seal 30 obtained by cutting along the section line EE shown.

[0157] In this embodiment, the contents that are the same as in the first embodiment will not be repeated. The difference is that the first vent groove 35 is disposed around the inner wall of the first through hole 33 in the circumferential direction. A fourth stepped surface 37 is formed on the sidewall of the first surface 34 of the first vent groove 35 away from the seal 30. The cross-sectional width D8 of the first vent groove 35 along the height direction of the seal body 31 is greater than the cross-sectional width D6 of the first sub-part 241 along the height direction of the protrusion 24. Furthermore, the description of the top cover assembly 100 below can be applied to the first embodiment above, unless otherwise specified.

[0158] Please refer to the following: Figure 18a and Figure 18b , Figure 18a 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 18b This is a schematic diagram of a portion of the structure of the top cover assembly 100 shown in 18a during the assembly process.

[0159] When the seal 30 is in the first state, the first vent groove 35 can surround a portion of the first sub-part 241 of the protrusion 24. That is, in the direction perpendicular to the height direction of the seal 30, the first vent groove 35 is disposed opposite to a portion of the first sub-part 241 of the protrusion 24. When the seal 30 is in the second state, the first vent groove 35 can surround all of the first sub-part 241 and a portion of the second sub-part 242 of the protrusion 24. That is, in the direction perpendicular to the height direction of the seal 30, the first vent groove 35 is disposed opposite to all of the first sub-part 241 of the protrusion 24, and also opposite to a portion of the second sub-part 242 of the protrusion 24.

[0160] In this embodiment, the number of third exhaust grooves 36 may not be equal to the number of first exhaust grooves 35. That is, there may be one or more third exhaust grooves 36. When there are multiple third exhaust grooves 36, each third exhaust groove 36 can be connected to a first exhaust groove 35.

[0161] Third embodiment:

[0162] Please see Figure 16 , Figure 17 , Figure 19 and Figure 20 , Figure 19 yes Figure 3The diagram shows another structural view of the lower plastic 20 portion of the top cover assembly 100 from one angle. Figure 20 yes Figure 19 This is a schematic diagram of another aspect of the structure of the lower plastic 20 shown.

[0163] In this embodiment, the contents that are the same as in the second embodiment will not be repeated. The difference is that the lower plastic 20 may be provided with a second venting groove 28. The opening of the second venting groove 28 is located on the outer peripheral surface of the protrusion 24. The outer peripheral surface of the protrusion 24 is a surface surrounding the central axis of the protrusion 24. The second venting groove 28 extends along the height direction of the protrusion 24 and communicates with the mounting groove 2321 of the retaining portion 23. 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.

[0164] Please refer to the following: Figure 21a and Figure 21b , Figure 21a 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 21b This is a schematic diagram of a portion of the structure of the top cover assembly 100 shown in 21a during the assembly process.

[0165] When the seal 30 is in the first state, the second vent groove 28 is isolated from the first vent groove 35. The distance L5 between the side wall of the second vent groove 28 away from the bottom plate 232 of the lower plastic 20 and the surface of the bottom plate 232 facing the lower plastic 20, and the distance L4 between the side wall of the first vent groove 35 away from the first surface 34 and the surface of the bottom plate 232 of the lower plastic 20 facing the lower plastic body 22, satisfy the relationship: L4-L5>0.2mm. This ensures that when the seal 30 is in the first state, there is good sealing performance between the seal 30 and the protrusion 24 of the lower plastic 20.

[0166] When the seal 30 is in the second state, a first gap T1 is formed between the outer peripheral surface of the protrusion 24 near the fastener 40 and the bottom wall of the first exhaust groove 35. A second gap T2 is formed between the bottom wall of the second exhaust groove 28 and the inner wall of the first through hole 33. A third gap T3 is formed between the bottom wall of the second exhaust groove 28 and the bottom wall of the first exhaust groove 35. The third gap T3 connects the first gap T1 and the second gap T2. The first air passage S1, the second gap T2, the third gap T3, and the first gap T1 are sequentially connected. Among them, the first gap T1, the second gap T2, the third gap T3, and the first through hole 33 cooperate to form the second air passage S2 described above.

[0167] The distance L5 between the side wall of the second vent groove 28 away from the bottom plate 232 of the lower plastic 20 and the surface of the bottom plate 232 facing the lower plastic 20 coincides with the distance L3 between the side wall of the first vent groove 35 away from the first surface 34 and the first surface 34, and satisfies the relationship: L5+L3>L2 (L2 is the distance between the first surface 34 and the surface of the bottom plate 232 of the lower plastic 20 facing the lower plastic body 22).

[0168] In this embodiment, the number of second exhaust grooves 28 can be one or more. When there are multiple second exhaust grooves 28, they are spaced apart along the circumferential direction of the protrusion 24. The circumferential direction of the protrusion 24 is the direction surrounding the central axis of the protrusion 24. A second gap T2 is formed between the bottom wall of each second exhaust groove 28 and the inner wall of the first through hole 33. A third gap T3 is formed between the bottom wall of each second exhaust groove 28 and the bottom wall of the first exhaust groove 35. The outer peripheral surface of the protrusion 24 located between two adjacent second exhaust grooves 28 abuts against the inner wall of the first through hole 33.

[0169] For example, there are four second exhaust grooves 28. The four second exhaust grooves 28 are spaced apart along the circumferential direction of the protrusion 24 and are located at four equal points on the outer peripheral surface of the protrusion 24.

[0170] 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 cap assembly, characterized by, The top cover assembly includes: A top cover, wherein the top cover is provided with a first liquid injection hole, the first liquid injection hole penetrating the top cover along the thickness direction; A sealing element is installed in the first injection hole; The lower plastic body includes a lower plastic body, a retaining portion, and a protrusion. The lower plastic body is stacked with the top cover. The lower plastic body has a second injection hole that penetrates the lower plastic body along its thickness direction and communicates with a first injection hole. The retaining portion is fixedly connected to the surface of the lower plastic body away from the top cover and extends towards the battery cell. The retaining portion has a mounting groove that communicates with the second injection hole and cooperates with the second injection hole to accommodate part of the sealing element. The protrusion is fixedly connected to the end of the retaining portion away from the lower plastic body and extends towards the lower plastic body. The protrusion is also located inside the mounting groove and the sealing element. Fastener, the fastener being located inside the first injection hole and sealingly connected to the top cover, the fastener abutting against the end of the seal away from the lower plastic; The enclosure is provided with a first air passage, which is connected to the outside of the lower plastic. A second air passage is formed between the protrusion and the sealing member. A third air passage is formed between the fastener and the end of the sealing member away from the lower plastic. The first air passage, the second air passage, and the third air passage are connected in sequence.

2. The roof assembly of claim 1, wherein, The sealing element is provided with a first through hole and a first exhaust groove. The first through hole penetrates the sealing element along the height direction. The opening of the first exhaust groove is located on the inner wall of the first through hole. The dimension of the first exhaust groove along the height direction of the sealing element is smaller than the height of the sealing element. The first exhaust groove is also connected to the third air passage. The protrusion includes a first sub-part and a second sub-part. The first sub-part and the second sub-part are coaxially arranged and connected. The second sub-part is connected between the first sub-part and the enclosure part. The first sub-part and at least a portion of the second sub-part are located within the first through hole. The cross-sectional width of the first sub-part along the height direction of the protrusion is greater than the cross-sectional width of the second sub-part along the height direction of the protrusion. In a direction perpendicular to the height direction of the protrusion, the first sub-part and a portion of the second sub-part are arranged opposite to the first exhaust groove. A first gap is formed between the outer peripheral surface of the first sub-part and the bottom wall of the first exhaust groove. A second gap is formed between the outer peripheral surface of the second sub-part and the inner wall of the first through hole. The second gap communicates with both the first gap and the first air passage, and cooperates with the first gap to form a portion of the second air passage.

3. The roof assembly of claim 2, wherein, The first exhaust groove is disposed around the inner wall of the first through hole along the circumferential direction of the first through hole, and the cross-sectional width of the first exhaust groove along the height direction of the seal is greater than the cross-sectional width of the first sub-part along the height direction of the protrusion.

4. The roof assembly of claim 2, wherein, The number of first exhaust grooves is multiple, and the multiple first exhaust grooves are spaced apart along the circumferential direction of the first through hole and all extend along the axial direction of the first through hole. The bottom wall of each first exhaust groove forms a first gap with the outer peripheral surface of the first sub-part. The inner wall of the first through hole located between two adjacent first exhaust grooves abuts against the outer peripheral surface of the first sub-part.

5. The roof assembly of claim 1, wherein, The sealing element is provided with a first through hole and a first exhaust groove. The first through hole penetrates the sealing element along the height direction. At least part of the protrusion is located in the first through hole. The opening of the first exhaust groove is located on the inner wall of the first through hole. The first exhaust groove is arranged around the inner wall of the first through hole along the circumferential direction and communicates with the third air passage. The dimension of the first exhaust groove along the height direction of the sealing element is smaller than the height of the sealing element. A first gap is formed between the bottom wall of the first exhaust groove and the outer peripheral surface of the protrusion. The protrusion is provided with a second exhaust groove. The opening of the second exhaust groove is located on the outer peripheral surface of the protrusion. A second gap is formed between the bottom wall of the second exhaust groove and the inner wall of the first through hole. The second gap is connected to both the first gap and the first air passage, and cooperates with the first gap to form a portion of the second air passage.

6. The roof assembly of any of claims 2-5, wherein, The seal includes a first surface that abuts against the fastener; The seal is provided with a third vent groove, the opening of which is located on the first surface. The third vent groove connects the first vent groove and the outside of the seal, forming the third air passage.

7. The roof assembly of any of claims 2-5, wherein, The sealing element includes a sealing element body and a limiting part. The sealing element body is provided with a first through hole and a first vent groove. The limiting part is connected around the outer peripheral surface of the sealing element body and protrudes relative to the outer peripheral surface of the sealing element body. The limiting part is interference-fitted with the inner wall of the first injection hole.

8. The roof assembly of claim 7, wherein, The first injection hole includes a first hole and a second hole. The first hole and the second hole are coaxially arranged and connected. The opening of the first hole away from the second hole is located on the surface of the top cover away from the lower plastic. The minimum width of the cross section of the first hole along the height direction of the first injection hole is greater than the maximum width of the cross section of the second hole along the height direction of the first injection hole. The sealing element includes a first state and a second state. When the seal is in the first state, the fastener is separated from both the seal and the top cover, the limiting part is interference-fitted to the connection between the first hole and the second hole, and the end of the protrusion away from the enclosure part is sealed to the inner wall of the first through hole. When the seal is in the second state, the fastener is located in the first hole and abuts against the seal. The fastener is also sealed to the top cover. The limiting part is interference-fitted to the inner wall of the second hole. The protrusion forms the second air passage between itself and the inner wall of the first through hole.

9. The roof assembly of claim 8, wherein, When the seal is in the first state, the length of the sealing connection area between the protrusion and the inner wall of the first through hole is greater than 0.2 mm in the height direction of the protrusion.

10. The roof assembly of claim 8, wherein, The fastener is provided with a first groove and a fourth vent groove. The opening of the first groove and the opening of the fourth vent groove are both located on the surface of the fastener facing the seal. The fourth vent groove also penetrates the outer peripheral surface of the fastener. When the seal is in the second state, part of the seal is located in the first groove and abuts against the bottom wall of the first groove. The first groove connects the fourth vent groove and the third air passage.

11. The roof assembly of any of claims 1-5, 8-10, wherein, The enclosure includes a side plate and a bottom plate. The bottom plate and the lower plastic body are spaced apart in the thickness direction of the lower plastic. The side plate is connected between the lower plastic body and the bottom plate and forms the mounting groove with the bottom plate. The protrusion is fixedly connected to the surface of the bottom plate facing the lower plastic body. The side plate is also provided with a second through hole, which penetrates the side plate along the thickness direction. The second through hole is connected to the mounting groove and cooperates with the mounting groove to form the first air passage.

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

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

Images