Pressure relief valve assembly, top cover assembly, battery and electrical device

Abstract

Provided in the present application are a pressure relief valve assembly, a top cover assembly, a battery and an electrical device. The pressure relief valve assembly comprises a pressing plate, an elastic member, a first sealing member and a second sealing member which are sequentially arranged in a first mounting recess of a top cover. The elastic member elastically abuts between the pressing plate and the first sealing member, the second sealing member is located between the first sealing member and the bottom wall of the first mounting recess, and the second sealing member is also located at an outer edge of an air inlet hole on the top cover. When the air pressure at the air inlet hole is greater than or equal to a preset threshold of the pressure relief valve assembly, the first sealing member is driven by gas at the air inlet hole to be separated from the second sealing member, and then the gas is discharged from the battery through the air inlet hole, a first air passage between the first sealing member and the side wall of the first mounting recess, a second air passage between the first sealing member and the pressing plate, a third air passage of the elastic member, and an air outlet hole on the pressing plate.

Description

Pressure relief valve assembly, top cover assembly, battery and electrical equipment

[0001] This application claims priority to Chinese Patent Application No. 202411754645.4, filed on December 2, 2024, entitled "Pressure relief valve assembly, top cover assembly, battery and electrical equipment", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of energy storage technology, and in particular to a pressure relief valve assembly, a top cover assembly, a battery, and electrical equipment. Background Technology

[0003] With the development of clean energy, batteries with recyclable characteristics are becoming increasingly popular. During battery use, chemical reactions occur inside the cell, producing a large amount of gas. Therefore, an explosion-proof valve structure is generally installed in the top cover assembly. The large amount of gas generated inside the cell can break through the explosion-proof valve and be discharged to the outside of the battery. However, although the explosion-proof valve can be opened to discharge gas to the outside of the battery, opening the valve can easily lead to a reduction in the life of the cell. Summary of the Invention

[0004] Embodiments of this application provide a pressure relief valve assembly, a top cover assembly, a battery, and an electrical device that can repeatedly vent the battery while ensuring the battery cell life.

[0005] In a first aspect, this application provides a pressure relief valve assembly for connection with a top cover. The top cover is provided with a first mounting groove and an air inlet. The pressure relief valve assembly includes a pressure plate, an elastic element, a first sealing element, and a second sealing element arranged sequentially in the first mounting groove. The elastic element elastically abuts against the pressure plate and the first sealing element. The second sealing element is located between the first sealing element and the bottom wall of the first mounting groove. The second sealing element is also located at the outer edge of the air inlet.

[0006] The gap area between the first seal and the side wall of the first mounting groove forms a first air passage, the gap area between the first seal and the pressure plate forms a second air passage, the elastic element is provided with a third air passage, the pressure plate is provided with an air outlet, and the air outlet connects the interior of the pressure relief valve assembly and the exterior of the pressure relief valve assembly.

[0007] When the air pressure at the air inlet is less than the preset threshold of the pressure relief valve assembly, the first seal is pressed against the second seal by the elastic member to seal the air inlet.

[0008] When the air pressure at the air inlet is greater than or equal to the preset threshold of the pressure relief valve assembly, the first seal is pushed by the gas at the air inlet and separates from the second seal. The air inlet, the first air passage, the second air passage, the third air passage and the air outlet are connected in sequence to form a gas channel for the gas at the air inlet to pass through.

[0009] During battery use, chemical reactions occur inside the battery cell, producing a large amount of gas. If too much gas accumulates, the battery can easily explode. Therefore, an explosion-proof valve assembly is usually installed in the top cover. When the gas pressure inside the battery cell reaches a certain value, the gas will break through the explosion-proof valve assembly and be released to the outside of the battery, thus preventing an explosion due to excessive internal pressure. However, once the explosion-proof valve explodes, it cannot be reused, and the explosion of the explosion-proof valve will also greatly reduce the lifespan of the battery cell.

[0010] Therefore, in the embodiments of this application, by providing a pressure relief valve assembly in the top cover assembly, the battery can be repeatedly vented, and the impact on the battery cell during the venting process can be reduced. Specifically, when a certain amount of gas is generated inside the battery cell, causing the gas pressure at the air inlet of the top cover to be greater than or equal to the preset threshold of the pressure relief valve assembly, the gas will sequentially pass through the air inlet of the top cover, the through hole on the second seal, and then push up the first seal, causing the first seal to compress the elastic element. The elastic element, under the pressure of the first seal, will move along the radial direction of the first seal, thereby reducing the height of the elastic element. As the first seal compresses the elastic element, the first seal separates from the second seal. The gas will enter the first air passage between the first seal and the side wall of the top cover through the gap between the second seal and the first seal. Then, it will enter the second air passage between the second seal and the pressure plate through the first air passage, and then diffuse into the third air passage of the elastic element, and finally be discharged to the outside of the battery through the air outlet of the pressure plate.

[0011] Alternatively, when the gas passes through the second seal, it can also enter the gap between the second seal and the side wall of the top cover through the gap between the second seal and the bottom wall of the first mounting groove, and then enter the first air passage between the first seal and the side wall of the top cover.

[0012] When the air pressure at the air inlet is lower than the preset threshold of the pressure relief valve assembly, the rebound force of the elastic element causes the first seal to press against the second seal, keeping the pressure relief valve assembly in a sealed state. The pressure relief valve assembly then stops venting, and this cycle repeats to achieve unidirectional venting of the pressure relief valve assembly. For example, the preset threshold can be 0.2 MPa. Of course, in other embodiments, the preset threshold can also be other values, and this is not strictly limited.

[0013] In summary, when the gas generated inside the battery cell causes the air pressure at the vent inlet of the top cover to be greater than or equal to the preset threshold of the pressure relief valve assembly, the pressure relief valve assembly will begin to vent the battery. When the air pressure at the vent inlet of the top cover is less than the preset threshold of the pressure relief valve assembly, the pressure relief valve assembly will stop venting. That is, the pressure relief valve assembly can repeatedly vent the battery, greatly improving the lifespan of the battery cell.

[0014] Secondly, this application also provides a top cover assembly, the top cover assembly including a top cover and a pressure relief valve assembly as described above, the top cover having a first mounting groove and an air inlet connected to each other, the pressure relief valve assembly being located in the first mounting groove and covering the air inlet.

[0015] Thirdly, 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.

[0016] Fourthly, this application also provides an electrical device, which includes the battery described above. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the background art, the accompanying drawings used in the embodiments of this application or the background art will be described below.

[0018] Figure 1 is a schematic diagram of the energy storage system provided in an embodiment of this application;

[0019] Figure 2 is a schematic diagram of a battery structure provided in an embodiment of this application;

[0020] Figure 3 is a schematic diagram of a top cover assembly provided in an embodiment of this application;

[0021] Figure 4 is an exploded structural diagram of the top cover assembly shown in Figure 3;

[0022] Figure 5a is a cross-sectional schematic diagram of a portion of the structure of the top cover assembly obtained by cutting along the cutting line AA shown in Figure 3.

[0023] Figure 5b is an enlarged view along region B in Figure 5a;

[0024] Figure 6a is a structural schematic diagram of the top cover of the top cover assembly shown in Figure 3 at one angle;

[0025] Figure 6b is a structural schematic diagram of the top cover of the top cover assembly shown in Figure 3 from another angle;

[0026] Figure 7 is another cross-sectional view of a portion of the top cover assembly obtained by cutting along section line AA shown in Figure 3.

[0027] Figure 8 is an exploded structural diagram of the pressure relief valve assembly of the top cover assembly shown in Figure 3;

[0028] Figure 9a is a structural schematic diagram of the pressure plate of the pressure relief valve assembly shown in Figure 8 at one angle;

[0029] Figure 9b is a structural schematic diagram of the pressure plate of the pressure relief valve assembly shown in Figure 8 from another angle;

[0030] Figure 10a is a schematic diagram of the elastic element of the pressure relief valve assembly shown in Figure 8;

[0031] Figure 10b is a schematic diagram of another structure of the elastic element of the pressure relief valve assembly shown in Figure 8;

[0032] Figure 11 is a schematic diagram of the assembly process of the elastic element and the pressure plate;

[0033] Figure 12a is a structural schematic diagram of the first seal of the pressure relief valve assembly shown in Figure 8 at one angle;

[0034] Figure 12b is a structural schematic diagram of the first seal of the pressure relief valve assembly shown in Figure 8 from another angle;

[0035] Figure 13a is a structural schematic diagram of the second seal of the pressure relief valve assembly shown in Figure 8 at one angle;

[0036] Figure 13b is a structural schematic diagram of the second seal of the pressure relief valve assembly shown in Figure 8 from another angle;

[0037] Figure 14a is a structural schematic diagram of the lower plastic of the top cover assembly shown in Figure 3 at one angle;

[0038] Figure 14b is a structural schematic diagram of the lower plastic of the top cover assembly shown in Figure 3 from another angle;

[0039] Figure 14c is a structural schematic diagram of the lower plastic of the top cover assembly shown in Figure 3 at another angle;

[0040] Figure 15 is a schematic diagram of one structure of the upper plastic of the top cover assembly shown in Figure 3;

[0041] Figure 16 is a schematic diagram of one structure of the pole of the top cover assembly shown in Figure 3.

[0042] Reference numerals: Energy storage system 500, power conversion device 510, first user load 520, second user load 530, electrical equipment 400, battery 300, casing 310, battery cell 320, top cover assembly 200, pressure relief valve assembly 100, top cover 210, lower plastic 220, upper plastic 230, terminal post 240, explosion-proof valve 250, explosion-proof valve protection plate 260, explosion-proof valve assembly F, pressure plate 10, elastic element 20, first sealing element 30, second sealing element 40, vent 11, pressure plate body 12, flange 13, first slot 14, first sub-part 131, etc. Second sub-part 132, second mounting groove 15, third mounting groove 16, first connecting part 21, support leg 22, third air passage S3, first sub-air passage S31, second sub-air passage S32, first connecting end 22a, second connecting end 22b, second connecting part 23, first distance d1, first sealing body 31, retaining wall 32, first surface 311, second surface 312, abutting surface 311a, first air passage S1, second air passage S2, inner ring body 41, outer ring body 42, first thickness T1, second thickness T2, first mounting groove 211, air inlet 212, third edge 213 a, Fourth edge 213b, First groove 2111, Second groove 2112, First stepped surface 2113, Second stepped surface 2114, First connecting surface 2115, Top cover body 214, Second protrusion 215, First surface 2141, Second surface 2142, First groove 216a, First through hole 216b, First boss 216c, Explosion-proof hole 217, First injection hole 218, Vent hole 221, Fourth mounting groove 222, First edge 223a, Second edge 223b, Second connecting surface 2221, Lower plastic body 224, First protrusion 2 25. Third surface 2241, fourth surface 2242, baffle 226, support 227, second groove 228a, second through hole 228b, second boss 228c, second injection hole 229, first height H1, second height H2, third height H3, fifth surface 231, sixth surface 232, third through hole 233, second slot 234, first side 234a, second side 234b, pole post body 241, pole post base 242, first body 2411, second body 2412, third body 2413, fourth body 2414. Detailed Implementation

[0043] For ease of understanding, the terminology used in the embodiments of this application will be explained first.

[0044] 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.

[0045] Multiple: refers to two or more.

[0046] 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.

[0047] 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.

[0048] Embodiments of this application provide a pressure relief valve assembly, a top cover assembly, a battery, and an electrical device.

[0049] 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.

[0050] Taking electrochemical energy storage as an example, an embodiment of this application provides an electrical device 400, which is equipped with a set of chemical batteries. The main purpose is to use the chemical elements in the chemical batteries as energy storage medium. The charging and discharging process is accompanied by the chemical reaction or change of the energy storage medium. Simply put, the electrical energy generated by wind and solar energy is stored in the chemical batteries. When the use of external electrical energy reaches its peak, the stored electricity is released for use, or transferred to places where electricity is scarce for use.

[0051] 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:

[0052] 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.

[0053] Small and medium-sized energy storage cabinets used in commercial and industrial energy storage scenarios on the user side, and small household energy storage boxes used in residential energy storage scenarios on the user side, mainly operate under the "peak shaving and valley filling" mode. Because there are significant price differences in electricity during peak and off-peak periods based on electricity demand, users typically charge the energy storage cabinets / boxes during off-peak hours to reduce costs; then, during peak hours, they release the electricity from the energy storage cabinets / boxes for use, thus saving on electricity bills. Furthermore, in remote areas and regions prone to natural disasters such as earthquakes and hurricanes, the presence of household energy storage cabinets / boxes effectively provides users with backup power for themselves and the power grid, eliminating the inconvenience caused by frequent power outages due to disasters or other reasons.

[0054] Please refer to Figure 1, which is a schematic diagram of the structure of the energy storage system 500 provided in an embodiment of this application. This embodiment of the application is illustrated using a home energy storage scenario in user-side energy storage as an example, but the electrical equipment 400 in this application is not limited to a home energy storage scenario.

[0055] Embodiments of this application provide an energy storage system 500, which includes a power conversion device 510, a first user load 520, a second user load 530, and an electrical device 400. The electrical device 400 is a small energy storage box that can be wall-mounted to an outdoor wall. Specifically, photovoltaic panels can convert solar energy into electrical energy during periods of low electricity prices, and the electrical device 400 stores this electrical energy and supplies it to streetlights and household appliances during peak electricity prices, or provides power during power outages / power interruptions.

[0056] The electrical device 400 may include, but is not limited to, individual batteries, battery modules, battery packs, and battery systems. When the electrical device 400 includes multiple batteries, the multiple batteries are electrically connected and all are located inside the casing of the electrical device 400, 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 in a combination of series and parallel connections to achieve greater capacity and power. The embodiments of this application are illustrated using the example of an electrical device 400 including batteries, but it should be understood that the electrical device 400 is not limited thereto.

[0057] Please refer to Figure 2, which is a schematic diagram of a battery 300 provided in an embodiment of this application.

[0058] For ease of description, the length direction of battery 300 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.

[0059] The battery 300 may include a top cover assembly 200, a housing 310, and a battery cell 320. The top cover assembly 200 is connected to the housing 310 and forms a receiving space with the housing 310, within which the battery cell 320 is located. Exemplarily, the top cover assembly 200 may be welded to the housing 310. The housing 310 may be made of a metallic material, such as aluminum alloy. The battery 300 may be a cylindrical battery 300 or a prismatic battery 300, etc.

[0060] It should be noted that Figure 2 is only intended to schematically illustrate the connection relationship between the top cover assembly 200, the housing 310, and the battery cell 320, and is not intended 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 300. In other embodiments of this application, the battery 300 may include more or fewer components than shown in Figure 2, or combine some components, or split some components, or have different component arrangements. The components shown in Figure 2 can be implemented in hardware, software, or a combination of both.

[0061] Please refer to Figures 3 and 4. Figure 3 is a structural schematic diagram of a top cover assembly 200 provided in an embodiment of this application, and Figure 4 is an exploded structural schematic diagram of the top cover assembly 200 shown in Figure 3.

[0062] The top cover assembly 200 may include a pressure relief valve assembly 100, a top cover 210, a lower plastic insert 220, an upper plastic insert 230, a terminal post 240, an explosion-proof valve 250, and an explosion-proof valve protection plate 260. The lower plastic insert 220 and the upper plastic insert 230 are sequentially mounted on the top cover 210 along the thickness direction (Z direction in the diagram). The terminal post 240 is mounted on the top cover 210 and insulated from the top cover 210 by the upper plastic insert 230 and the lower plastic insert 220. The terminal post 240 can serve as an electrode lead-out of the battery 300. The pressure relief valve assembly 100 is connected to the top cover 210 and is spaced apart from the terminal post 240 along the length direction (X direction in the diagram) of the top cover 210. The pressure relief valve assembly 100 is used for pressure relief protection of the battery 300. The explosion-proof valve assembly F is connected to the top cover 210 and is spaced apart from the pressure relief valve assembly 100 and the terminal post 240 along the length of the top cover 210, also serving as pressure relief protection for the battery 300. The explosion-proof valve assembly F may include an explosion-proof valve 250 and an explosion-proof valve protection plate 260. Both the explosion-proof valve 250 and the explosion-proof valve protection plate 260 are connected to the explosion-proof hole 217 on the top cover 210 and are arranged sequentially along the thickness direction of the top cover 210. The explosion-proof valve protection plate 260 covers the explosion-proof valve 250.

[0063] In the embodiments of this application, the number of terminals 240 can be two. The two terminals 240 are a positive terminal and a negative terminal, respectively. The two terminals 240 are spaced apart along the length of the top cover 210. The number of upper plastic parts 230 can also be two. One upper plastic part 230 is fitted onto the positive terminal. The other upper plastic part 230 is fitted onto the negative terminal. The structure of the top cover assembly 200 will be described below using the assembly of one terminal 240, one upper plastic part 230, the top cover 210, and the lower plastic part 220 as an example. Unless otherwise specified, the description of the structure of one terminal 240 and one upper plastic part 230 below can be applied to other terminals 240 and upper plastic parts 230.

[0064] Please refer to Figures 5a, 5b, 6a, and 6b. Figure 5a is a cross-sectional view of a portion of the structure of the top cover assembly 200 obtained by cutting along the section line AA shown in Figure 3. Figure 5b is an enlarged view along region B in Figure 5a. Figure 6a is a structural schematic diagram of the top cover 210 of the top cover assembly 200 shown in Figure 3 at one angle. Figure 6b is a structural schematic diagram of the top cover 210 of the top cover assembly 200 shown in Figure 3 at another angle.

[0065] The top cover 210 may be provided with a first mounting groove 211 and an air inlet 212. The opening of the first mounting groove 211 is located on the surface of the top cover 210 opposite to the battery cell 320. The first mounting groove 211 may be recessed from the surface of the top cover 210 opposite to the battery cell 320 into the interior of the top cover 210. The first mounting groove 211 is used to install the pressure relief valve assembly 100. The air inlet 212 penetrates the bottom wall of the first mounting groove 211 along the thickness direction of the top cover 210. The air inlet 212 is coaxially arranged with and connected to the first mounting groove 211. The air inlet 212 may be covered by the pressure relief valve assembly 100. The air inlet 212 may be sealed by the first sealing member 30 when the air pressure at its location is less than a preset threshold. Alternatively, the air inlet 212 may be connected to the air outlet 11 of the pressure plate 10 when the air pressure at its location is greater than or equal to the preset threshold, so as to allow the gas generated inside the battery cell 320 to pass through.

[0066] The first mounting groove 211 may include a first groove 2111 and a second groove 2112. The first groove 2111 and the second groove 2112 are coaxially arranged and connected. The opening of the first groove 2111 can be the opening of the first mounting groove 2111. The first groove 2111 can be used to accommodate the pressure plate 10 and part of the elastic element 20. The bottom wall of the second groove 2112 can be the bottom wall of the first mounting groove 211. The cross-sectional width of the second groove 2112 along the thickness direction of the top cover 210 can be smaller than the cross-sectional width of the first groove 2111 along the thickness direction of the top cover 210. The second groove 2112 can be used to accommodate the first sealing element 30, the second sealing element 40, and part of the elastic element 20.

[0067] The connection between the first groove 2111 and the second groove 2112 can form a first stepped surface 2113 and a second stepped surface 2114. The first stepped surface 2113 can be the bottom wall of the first groove 2111. The first stepped surface 2113 can be parallel to the bottom wall of the first mounting groove 211 and can be used to abut against the pressure plate 10. The second stepped surface 2114 can be the inner peripheral wall of the second groove 2112. The inner peripheral wall of the second groove 2112 is the inner surface surrounding the central axis of the second groove 2112. The second stepped surface 2114 can be perpendicular to the first stepped surface 2113.

[0068] Understandably, by forming a stepped surface within the first mounting groove 211 of the top cover 210 to support the pressure plate 10, the pressure plate 10 abuts against and is fixed to the stepped surface. When the elastic element 20 is compressed by the pressure of the first sealing element 30, the pressure plate 10 connected to the elastic element 20 can remain stationary, ensuring the connection stability of the pressure relief valve assembly 100. Simultaneously, the contact between the pressure plate 10 and the stepped surface also enhances the sealing performance of the pressure relief valve assembly 100.

[0069] The top cover 210 may include a third edge 213a and a fourth edge 213b. The third edge 213a and the fourth edge 213b are disposed opposite each other in the width direction (Y direction in the diagram) of the top cover 210. The distance between the central axis of the first mounting groove 211 and the third edge 213a is equal to the distance between the centerline of the first mounting groove 211 and the fourth edge 213b (within allowable tolerance). That is, along the width direction of the top cover 210, the first mounting groove 211 is located at the middle position of the top cover 210 (within allowable tolerance).

[0070] The first mounting groove 211 may include a first connecting surface 2115. The first connecting surface 2115 forms at least a portion of the bottom wall of the first mounting groove 211. The first connecting surface 2115 surrounds and is connected to the outer edge of the air inlet 212, and is coaxially arranged with the air inlet 212. That is, the first connecting surface 2115 is annular and surrounds the air inlet 212. In the thickness direction of the top cover assembly 200 (Z direction in the figure), the distance between the first connecting surface 2115 and the opening of the first mounting groove 211 gradually decreases from the end connected to the air inlet 212 towards the end away from the air inlet 212. That is, the first connecting surface 2115 is a slope.

[0071] Understandably, during the process of venting the battery 300 through the pressure relief valve assembly 100, electrolyte in the cell 320 may enter the first mounting groove 211 due to air pressure. Therefore, by setting the bottom wall of the first mounting groove 211 around the air inlet 212 as a slope, electrolyte splashed into the first mounting groove 211 can flow into the air inlet 212 through the slope and then back into the cell 320, preventing electrolyte from splashing out of the battery 300 through the pressure relief valve assembly 100.

[0072] In some other embodiments, in the thickness direction of the top cover assembly 200, the distance between the first connecting surface 2115 and the opening of the first mounting groove 211 can remain constant and then gradually decrease from the end connected to the air inlet 212 to the end away from the air inlet 212.

[0073] In some other embodiments, the first connecting surface 2115 may also form the entire bottom wall of the first mounting groove 211. That is, the first connecting surface 2115 is the bottom wall of the first mounting groove 211. In this case, in the thickness direction of the top cover assembly 200, the distance between the first connecting surface 2115 and the opening of the first mounting groove 211 gradually decreases from the end connected to the air inlet 212 towards the end away from the air inlet 212. Alternatively, in the thickness direction of the top cover assembly 200, the distance between the first connecting surface 2115 and the opening of the first mounting groove 211 may remain constant initially and then gradually decrease from the end connected to the air inlet 212 towards the end away from the air inlet 212.

[0074] The embodiments of this application do not limit the proportion of the first connecting surface 2115 occupying the bottom wall of the first mounting groove 211, as long as the electrolyte splashed into the first mounting groove 211 can flow into and back to the battery cell 320 through the inclined surface on the bottom wall of the first mounting groove 211.

[0075] In embodiments of this application, the top cover 210 may include a top cover body 214 and a second protrusion 215. The second protrusion 215 is connected to the top cover body 214 and protrudes from the surface of the top cover body 214 toward the lower plastic 220. The second protrusion 215 and the top cover body 214 can be connected to form an integral structure. Exemplarily, the second protrusion 215 and the top cover body 214 can be an integral structure formed by connecting them through methods such as integral molding. Alternatively, the second protrusion 215 and the top cover body 214 can also be an integral structure formed by connecting them through assembly methods such as welding or bonding. It should be noted that the integral structures described below can all be formed by connecting them through assembly methods such as integral molding, welding, or bonding, and will not be described again.

[0076] Please refer to Figures 5a, 6a, 6b, and 7. Figure 7 is another cross-sectional view of a portion of the top cover assembly 200 obtained by cutting along section line AA shown in Figure 3. The top cover body 214 may include a first surface 2141 and a second surface 2142. The first surface 2141 and the second surface 2142 are disposed opposite to each other in the thickness direction (Z direction shown in the figure) of the top cover body 214. The first surface 2141 is away from the battery cell 320. The second surface 2142 faces the battery cell 320. The second surface 2142 may be connected to the third surface 2241 of the lower plastic 220 and the surface of the electrode base 242 of the electrode post 240 near the electrode body 241. The second protrusion 215 is connected to the second surface 2142 of the top cover body 214 and is located in the fourth mounting groove 222 of the lower plastic 220.

[0077] The top cover body 214 and the second protrusion 215 may be provided with the air inlet 212 and the first mounting groove 211 described above. Both the air inlet 212 and the first mounting groove 211 are coaxially arranged with the second protrusion 215. The air inlet 212 can penetrate the first surface 2141 and the surface of the second protrusion 215 away from the surface of the top cover body 214. That is, the first through hole 216b can penetrate the top cover body 214 and the second protrusion 215 along the thickness direction of the top cover 210. The opening of the first mounting groove 211 is located on the first surface 2141. The first mounting groove 211 can be recessed from the first surface 2141 into the interior of the top cover 210 and the second protrusion 215. The first groove 2111 is located within the top cover body 214, and the second groove 2112 is located within the second protrusion 215 and a portion of the top cover body 214. In some other embodiments, the first groove 2111 may be located within the top cover body 214, the second groove 2112 may be located within the second protrusion 215, and the first stepped surface 2113 may be flush with the second surface 2142. Alternatively, the first groove 2111 may be located within the top cover body 214 and part of the second protrusion 215, and the second groove 2112 may be located within the second protrusion 215.

[0078] Referring to Figures 6a, 6b, and 7, the top cover 210 may have a first groove 216a and a first through hole 216b. The opening of the first groove 216a is located on the surface of the top cover 210 facing the battery cell 320. That is, the opening of the first groove 216a is located on the second surface 2142 of the top cover 210. The first groove 216a may be recessed from the second surface 2142 into the interior of the top cover 210. The first groove 216a may be used to accommodate the second boss 228c of the lower plastic 220, a portion of the upper plastic 230, and a portion of the electrode base 242 of the electrode post 240. The first through hole 216b may penetrate the top cover 210 along its thickness direction. The first through hole 216b is coaxially arranged with and connected to the first groove 216a. The first through hole 216b may communicate with the third through hole 233 of the upper plastic 230 and the second through hole 228b of the lower plastic 220. The first through hole 216b is used for the pole post 240 to pass through.

[0079] The top cover 210 may have two first grooves 216a, spaced apart along its length (X direction in the diagram). Each first groove 216a can be used to mount a second boss 228c of the lower plastic 220, a portion of the upper plastic 230, and a portion of the electrode base 242 of the electrode post 240. The top cover 210 may also have two first through holes 216b, spaced apart along its length and coaxially connected to the two first grooves 216a. One first through hole 216b is for the positive electrode post to pass through, and the other is for the negative electrode post to pass through.

[0080] In embodiments of this application, the top cover 210 may include a first boss 216c. The first boss 216c is connected to the first surface 2141 of the top cover body 214 and protrudes relative to the first surface 2141. The first boss 216c and the top cover body 214 can be connected by means such as integral molding to form an integral structure. The first boss 216c is located in the second slot 234 of the upper plastic 230. The surface of the first boss 216c facing away from the top cover body 214 abuts against the first side 234a of the second slot 234 of the upper plastic 230. In some other embodiments, the top cover 210 may not include the first boss 216c, as long as the top cover 210 can be installed in the second slot 234 of the upper plastic 230.

[0081] For example, there may be two first protrusions 216c, which are spaced apart along the length of the top cover 210. Each first protrusion 216c is connected to a second slot 234 of the upper plastic 230.

[0082] The top cover body 214 and the first boss 216c may be provided with the first through hole 216b and the first groove 216a described above. The first through hole 216b can penetrate the second surface 2142 and the first boss 216c away from the surface of the top cover body 214. That is, the first through hole 216b can penetrate the top cover body 214 and the first boss 216c along the thickness direction of the top cover 210. The opening of the first groove 216a is located on the second surface 2142. The first groove 216a can be recessed from the second surface 2142 into the interior of the top cover 210. The bottom wall of the first groove 216a abuts against the second side 234b of the second slot 234 of the upper plastic 230. The bottom wall of the first groove 216a can be located inside the top cover body 214. Alternatively, the bottom wall of the first groove 216a can be located inside the first boss 216c. Alternatively, the bottom wall of the first groove 216a can be flush with the first surface 2141. In the embodiments of this application, the depth of the first groove 216a is not limited, as long as the distance between the bottom wall of the first groove 216a and the surface of the first boss 216c away from the top cover body 214 is equal to the distance between the two inner peripheral surfaces of the second slot 234 of the upper plastic 230.

[0083] The top cover 210 may also be provided with an explosion-proof hole 217 and a first liquid injection hole 218. Specifically, along the length direction (X direction in the figure) of the top cover body 214, the explosion-proof hole 217 is located between the air inlet hole 212 and the first through hole 216b, and is spaced apart from both the air inlet hole 212 and the first through hole 216b. That is, the explosion-proof valve assembly F is spaced apart from the pressure relief valve assembly 100. The explosion-proof hole 217 can penetrate the first surface 2141 and the second surface 2142. That is, the explosion-proof hole 217 penetrates the top cover body 214 along the thickness direction of the top cover body 214. The explosion-proof hole 217 is used to connect with the explosion-proof valve 250 and the explosion-proof valve protection plate 260.

[0084] Along the length of the top cover body 214, a first injection hole 218 can be disposed between the explosion-proof hole 217 and the first through hole 216b, and located at both ends of the explosion-proof hole 217, respectively, and the air inlet 212. The first injection hole 218 and the explosion-proof hole 217, and the first through hole 216b and the air inlet 212 are all spaced apart. The first injection hole 218 can penetrate through the first surface 2141 and the second surface 2142. That is, the first injection hole 218 penetrates the top cover body 214 along its thickness direction. The first injection hole 218 is used to inject electrolyte into the battery cell 320.

[0085] Please refer to Figures 5a, 5b, and 8. Figure 8 is an exploded structural diagram of the pressure relief valve assembly 100 of the top cover assembly 200 shown in Figure 3. The pressure relief valve assembly 100 is located within the first mounting groove 211 of the top cover 210. The pressure relief valve assembly 100 may include a pressure plate 10, an elastic element 20, a first seal 30, and a second seal 40 arranged sequentially. The pressure plate 10 is located near the opening of the first mounting groove 211 of the top cover 210. The elastic element 20 elastically abuts against the pressure plate 10 and the first seal 30. The second seal 40 is connected between the first seal 30 and the bottom wall of the first mounting groove 211 of the top cover 210.

[0086] Please refer to Figures 5a, 5b, 9a and 9b. Figure 9a is a structural schematic diagram of the pressure plate 10 of the pressure relief valve assembly 100 shown in Figure 8 from one angle, and Figure 9b is a structural schematic diagram of the pressure plate 10 of the pressure relief valve assembly 100 shown in Figure 8 from another angle.

[0087] The pressure plate 10 may be provided with an air outlet 11. The air outlet 11 extends through the pressure plate 10 along its thickness direction (Z direction in the figure). The air outlet 11 is used to connect the interior and exterior of the pressure relief valve assembly 100 and to allow gas generated inside the power core 320 to pass through.

[0088] Specifically, the pressure plate 10 may include a pressure plate body 12 and a flange 13. The pressure plate body 12 is located within the first groove 2111 of the first mounting groove 211 of the top cover 210. The surface of the pressure plate body 12 facing the elastic member 20 can abut against the first stepped surface 2113 of the top cover 210 and is spaced apart from the surface of the first sealing member 30 facing the pressure plate 10. The pressure plate body 12 is provided with the vent 11 described above. The vent 11 penetrates the pressure plate body 12 along its thickness direction (Z direction in the figure).

[0089] The flange 13 is located on the side of the pressure plate body 12 facing the elastic member 20. One end of the flange 13 is connected to the outer edge of the vent 11. The other end of the flange 13 is projected into the pressure plate body 12 along the thickness direction of the pressure plate 10. That is, the flange 13 is bent relative to the pressure plate body 12. The flange 13 and the pressure plate body 12 cooperate to form a first slot 14. The first slot 14 is used to install part of the elastic member 20.

[0090] The flange 13 may include a first sub-part 131 and a second sub-part 132. The first sub-part 131 is bent and connected between the pressure plate body 12 and the second sub-part 132. The first sub-part 131 and the second sub-part 132 may be coaxially arranged and both protrude relative to the surface of the pressure plate body 12 toward the elastic member 20. Specifically, the first sub-part 131 is arranged around the outer edge of the vent 11 and may be arranged substantially perpendicular to the pressure plate body 12. That is, the first sub-part 131 is annular and surrounds the vent 11. The second sub-part 132 is connected to the end of the first sub-part 131 away from the vent 11 and may be arranged substantially parallel to the pressure plate body 12. The second sub-part 132 may be annular.

[0091] The first sub-part 131 and the second sub-part 132 of the flange 13 cooperate with the pressure plate body 12 to form a first slot 14. The surface of the first sub-part 131 facing away from the vent 11 forms the bottom wall of the first slot 14. The surface of the second sub-part 132 facing the pressure plate body 12 and the surface of the pressure plate body 12 facing the elastic member 20 cooperate to form the two side walls of the first slot 14. The pressure plate body 12 and the first sub-parts 131 and 132 of the flange 13 can be connected by means such as integral molding to form an integral structure.

[0092] It is understandable that by setting a flange 13 on the pressure plate 10 and forming a first slot 14 on the pressure plate 10, the elastic element 20 can be snapped into this slot, thereby achieving a fixed connection between the elastic element 20 and the pressure plate 10 and enhancing the connection stability between the elastic element 20 and the pressure plate 10.

[0093] The pressure plate 10 may be provided with a second mounting groove 15. Specifically, the second mounting groove 15 is located on the pressure plate body 12. The opening of the second mounting groove 15 is located on the surface of the pressure plate body 12 facing the elastic member 20. The second mounting groove 15 is recessed from the surface of the pressure plate body 12 facing the elastic member 20 into the interior of the pressure plate body 12. The second mounting groove 15 is coaxially arranged with the vent 11 and the flange 13. The second mounting groove 15 communicates with the first retaining groove 14. A portion of the bottom wall of the second mounting groove 15 and the surface of the second sub-part 132 facing the pressure plate body 12 can cooperate to form the sidewall of the first retaining groove 14. The second mounting groove 15 can be used to mount part of the elastic member 20 and accommodate part of the first connecting portion 21 of the elastic member 20. The depth of the second mounting groove 15 can be equal to the height of the first sub-part 131 along the thickness direction of the pressure plate 10.

[0094] In some other embodiments, the depth of the second mounting groove 15 may be greater than the height of the first sub-part 131 along the thickness direction of the pressure plate 10. Alternatively, the depth of the second mounting groove 15 may be less than the height of the first sub-part 131 along the thickness direction of the pressure plate 10.

[0095] It is understandable that by providing a second mounting groove 15 on the pressure plate 10, the thickness of the pressure plate 10 can be reduced while ensuring its strength. Furthermore, since the second mounting groove 15 can also accommodate part of the elastic element 20, during the assembly of the pressure relief valve assembly 100, the second mounting groove 15 can limit the elastic element 20, making it easier and more convenient for the pressure plate 10 to bend to form a flange 13 and for the flange 13 to be fixed to the elastic element 20.

[0096] The pressure plate 10 may also be provided with a third mounting groove 16. The opening of the third mounting groove 16 is located on the surface of the pressure plate body 12 opposite to the elastic member 20. The third mounting groove 16 is recessed from the surface of the pressure plate body 12 opposite to the elastic member 20 into the interior of the pressure plate body 12. The third mounting groove 16 is coaxially arranged with the vent 11 and communicates with the vent 11. The third mounting groove 16 is used to mount the pressure member.

[0097] Understandably, during the assembly of battery 300, placing a weighted component on the third mounting slot 16 of pressure plate 10 allows pressure plate 10 to remain connected to the first step surface 2113 of top cover 210, thus facilitating the setting of the opening threshold of pressure relief valve assembly 100. For example, placing a 0.4kg weighted component on the third mounting slot 16 of pressure plate 10, connecting pressure plate 10 to top cover 210, sets the preset opening threshold of pressure relief valve assembly 100 to 0.2MPa. Changing the weight of the weighted component correspondingly changes the opening threshold of pressure relief valve assembly 100. The preset threshold is the air pressure value required to open pressure relief valve assembly 100.

[0098] Please refer to Figures 5a, 5b and 10a. Figure 10a is a schematic diagram of the structure of the elastic element 20 of the pressure relief valve assembly 100 shown in Figure 8.

[0099] The elastic element 20 is connected between the pressure plate 10 and the first sealing element 30, and is located within the first groove 2111 and the second groove 2112 of the first mounting groove 211 of the top cover 210. The elastic element 20 may include a first connecting portion 21 and a plurality of support legs 22. The plurality of support legs 22 are spaced apart in the circumferential direction of the first connecting portion 21. The circumferential direction of the first connecting portion 21 is the direction around the central axis of the first connecting portion 21. The plurality of support legs 22 and the first connecting portion 21 can be connected to form an integral structure by means such as integral molding. The elastic element 20 may be made of a highly elastic material. For example, the elastic element 20 may be made of 60Si2Mn material. Each 60Si2Mn molecule consists of 60 Si atoms and 2 Mn atoms.

[0100] The first connecting portion 21 may be provided with a second sub-air passage S32. The second sub-air passage S32 extends through the first connecting portion 21 along its thickness direction (Z direction in the figure) and communicates with the air outlet 11 of the pressure plate 10. The second sub-air passage S32 can be used to allow gas to pass through the power supply core 320. The first connecting portion 21 may include an inner edge and an outer edge. The inner edge of the first connecting portion 21 is the outer edge of the second sub-air passage S32. The outer edge of the first connecting portion 21 is away from the second sub-air passage S32. The first connecting portion 21 abuts against the pressure plate 10 and is located in the first slot 14 of the pressure plate 10. The inner edge of the first connecting portion 21 is covered by the pressure plate 10. The thickness of the first connecting portion 21 along the thickness direction (Z direction in the figure) of the elastic member 20 may be equal to the height of the first sub-part 131 along the thickness direction of the pressure plate 10, or it may be equal to the distance between the two side walls of the first slot 14. Specifically, the surface of the first connecting portion 21 facing the first seal 30 and the surface facing away from the first seal 30 respectively abut against the two side walls of the first slot 14. The inner circumferential surface of the first connecting portion 21 abuts against the bottom wall of the first slot 14. The inner circumferential surface of the first connecting portion 21 is the inner surface surrounding the central axis of the first connecting portion 21, and is also the inner wall of the second sub-air passage S32. That is, the elastic member 20 abuts between the pressure plate body 12 and the flange 13.

[0101] Each leg 22 may include a first connecting end 22a and a second connecting end 22b. The first connecting end 22a of the leg 22 is fixedly connected to the outer edge of the first connecting portion 21. The second connecting end 22b of the leg 22 abuts against the first surface 311 of the first seal 30 and is spaced apart from the retaining wall 32 of the first seal 30. The second connecting end 22b of the leg 22 is movable relative to the first surface 311 of the first seal 30 in the radial direction of the first connecting portion 21. Specifically, when the elastic member 20 is compressed by the first seal 30, the second connecting end 22b of the leg 22 moves from the central axis of the second connecting portion 23 toward the retaining wall 32 of the first seal 30, thereby reducing the thickness (i.e., height) of the elastic member 20 in the thickness direction of the top cover assembly 200.

[0102] The second connecting end 22b of the support leg 22 can be in line contact with the first surface 311 of the first seal 30. Exemplarily, the second connecting end 22b of the support leg 22 is curved upwards relative to the first surface 311 of the first seal 30 from the first seal 30 toward the elastic member 20. The second connecting end 22b of the support leg 22 can be an arc-shaped structure. Furthermore, designing the second connecting end 22b of the support leg 22 as an arc portion can prevent the elastic member 20 from scratching the first seal 30 during movement, thus avoiding damage to the surface of the first seal 30 and affecting the rebound effect of the elastic member 20.

[0103] It is understandable that by making the second connecting end 22b of the support leg 22 form a line contact with the first seal 30, the elastic element 20 and the first seal 30 can form a line contact, thereby reducing the difficulty of the support leg 22 moving when the elastic element 20 is under force, and making it easier for the second connecting end 22b of the support leg 22 to move in the radial direction of the first connecting part 21.

[0104] Furthermore, the first connecting portion 21 of the elastic element 20 is installed in the first slot 14 of the pressure plate 10, and the second connecting end 22b of the support leg 22 is movable relative to the first sealing element 30. When the elastic element 20 is subjected to pressure inside the battery 300, the height of the elastic element 20 can be reduced by moving the second connecting end 22b of the support leg 22, while the first connecting portion 21 of the elastic element 20 connected to the pressure plate 10 is fixed by the first slot 14 and will not move, ensuring the stability of the pressure relief valve assembly 100 during the venting and pressure relief process.

[0105] In the embodiments of this application, please refer to Figures 5a, 5b, and 10b. Figure 10b is a schematic diagram of another structure of the elastic element 20 of the pressure relief valve assembly 100 shown in Figure 8. The elastic element 20 may further include a second connecting portion 23. The second connecting portion 23 may be annular. The inner edge of the second connecting portion 23 is connected to the second connecting end 22b of the support leg 22. The second connecting portion 23 and the first connecting portion 21 are spaced apart in the thickness direction of the elastic element 20 and are located in the second groove 2112 of the first mounting groove 211 of the top cover 210. The second connecting portion 23 abuts against the first surface 311 of the first seal 30 and is movable relative to the first surface 311 of the first seal 30 in the radial direction of the first connecting portion 21. Specifically, when the elastic element 20 is compressed by the first seal 30, the second connecting portion 23 moves from the central axis of the second connecting portion 23 toward the retaining wall 32 of the first seal 30. That is, when the elastic element 20 is compressed by the first sealing element 30, the cross-sectional width of the second connecting portion 23 along the thickness direction of the elastic element 20 gradually increases. This causes the second connecting end 22b of the support leg 22 to move from the central axis of the second connecting portion 23 toward the baffle 32 of the first sealing element 30, thereby reducing the thickness (i.e., height) of the elastic element 20 along the thickness direction of the top cover assembly 200.

[0106] The second connecting portion 23 and the first surface 311 of the first seal 30 can be in line contact. For example, the second connecting portion 23 is raised relative to the first surface 311 of the first seal 30 from the first seal 30 toward the elastic member 20. Forming a line contact between the second connecting portion 23 and the first seal 30 reduces the difficulty of movement of the second connecting portion 23 when the elastic member 20 is under force, facilitating movement of the second connecting portion 23 along the radial direction of the first connecting portion 21. The end of the second connecting portion 23 facing away from the second connecting end 22b of the support leg 22 can be an arc-shaped structure. Designing the second connecting portion 23 as an arc portion avoids scratching the first seal 30 when the elastic member 20 moves, preventing surface damage to the first seal 30 and thus affecting the rebound effect of the elastic member 20.

[0107] It is understandable that by setting the second connecting part 23, the second connecting ends 22b of multiple legs 22 can be connected together, so that when the elastic member 20 is subjected to pressure in the battery cell 320, the force is more even when the second connecting part 23 moves relative to the first sealing member 30, making the pressure relief valve assembly 100 more stable.

[0108] In embodiments of this application, the elastic element 20 may be provided with a third air passage S3. The third air passage S3 may include a first sub-air passage S31 and the second sub-air passage S32 described above. The first sub-air passage S31 is composed of the gap region between multiple adjacent support legs 22. The first sub-air passage S31 and the second sub-air passage S32 are connected through a space formed by a first connecting portion 21, a second connecting portion 23, and the multiple support legs 22. The third air passage S3 is used for the passage of gas generated within the power supply core 320.

[0109] It is understandable that by setting a third air passage S3 in the elastic member 20, and connecting the first sub-air passage S31 in the third air passage S3 with the first air passage S1 between the first sealing member 30 and the second step surface 2114 of the top cover 210, and connecting the second sub-air passage S32 in the third air passage S3 with the air outlet 11 of the pressure plate 10, the third air passage S3 can be connected between the second air passage S2 and the air outlet 11, so that when the pressure relief valve assembly 100 is venting, the gas generated by the battery cell 320 can be normally discharged to the outside of the pressure relief valve assembly 100.

[0110] Please refer to Figure 11, which is a schematic diagram of the assembly process of the elastic element 20 and the pressure plate 10. In the embodiments of this application, the assembly process of the elastic element 20 and the pressure plate 10 may include at least the following steps:

[0111] First, a second mounting groove 15 is formed on the surface of the pressure plate 10 facing the cell 320.

[0112] Secondly, the pressure plate 10 area around the central axis of the pressure plate 10 is bent for the first time, and this part of the pressure plate 10 area is bent to be perpendicular to the original pressure plate 10 (i.e. the pressure plate body 12). The bent pressure plate 10 forms a flange 13, and the flange 13 extends from the pressure plate 10 toward the battery cell 320. At this time, the original area of ​​the flange 13 on the pressure plate 10 forms an air outlet 11.

[0113] Then, the elastic member 20 is installed on the pressure plate 10, such that the first connecting portion 21 of the elastic member 20, facing away from the surface of the battery cell 320, abuts against the bottom wall of the second mounting groove 15 of the pressure plate 10, and the inner edge of the first connecting portion 21 is connected to the outer peripheral surface of the partial flange 13. The outer peripheral surface of the flange 13 is the outer surface that surrounds the central axis of the flange 13.

[0114] Next, the portion of the flange 13 not connected to the first connecting part 21 is bent a second time, so that the first connecting part 21 is fixed by the flange 13 and the pressure plate body 12. The specific bending process is as follows: this portion of the flange 13 is bent at 45° away from the central axis of the pressure plate 10, and then riveted to make this portion of the flange 13 parallel to the pressure plate body 12. This portion of the flange 13 is the second sub-part 132 of the flange 13, and the flange 13 that only undergoes the first bending process is the first sub-part 131 of the flange 13. The first sub-part 131, the second sub-part 132, and the bottom wall of the second mounting groove 15 together form the first slot 14.

[0115] Please refer to Figures 5a, 5b, 12a and 12b. Figure 12a is a structural schematic diagram of the first seal 30 of the pressure relief valve assembly 100 shown in Figure 8 from one angle, and Figure 12b is a structural schematic diagram of the first seal 30 of the pressure relief valve assembly 100 shown in Figure 8 from another angle.

[0116] The first seal 30 is located in the second groove 2112 of the first mounting groove 211 of the top cover 210. There is a gap between the outer peripheral surface of the first seal 30 and the inner peripheral wall of the second groove 2112 to allow gas in the power core 320 to pass through. The outer peripheral surface of the first seal 30 is the outer surface surrounding the central axis of the first seal 30.

[0117] The first seal 30 may include a first sealing body 31 and a barrier 32. The barrier 32 is connected around the outer edge of the first sealing body 31 and protrudes from the first seal 30 toward the elastic member 20 relative to the first sealing body 31. That is, the barrier 32 is annular and surrounds the first sealing body 31. The barrier 32 and the first sealing body 31 may be an integral structure formed by means such as integral molding.

[0118] The first sealing body 31 may include a first surface 311 and a second surface 312. The first surface 311 and the second surface 312 are disposed opposite each other in the thickness direction (Z direction in the figure) of the first sealing body 31. The first surface 311 faces away from the battery cell 320. The first surface 311 can abut against the elastic member 20. The second surface 312 faces the battery cell 320. The second surface 312 can abut against the second sealing member 40.

[0119] The portion of the first surface 311 that contacts the elastic member 20 can be planar. Specifically, the first surface 311 may include an abutting surface 311a that abuts against the elastic member 20. That is, the abutting surface 311a forms at least a portion of the first surface 311 and extends along the circumferential direction of the first sealing body 31. The circumferential direction of the first sealing body 31 is the direction surrounding the central axis of the first sealing body 31. The abutting surface 311a is arranged parallel to the bottom wall of the first mounting groove 211 of the top cover 210.

[0120] It is understandable that by aligning the abutment surface 311a of the first seal 30 parallel to the bottom wall of the first mounting groove 211 of the top cover 210, the contact position between the elastic element 20 and the first seal 30 can be kept flat, thus ensuring the structural stability of the pressure relief valve assembly 100 during pressure relief. Furthermore, the smaller the area of ​​the abutment surface 311a, the better its flatness is guaranteed.

[0121] In one possible application scenario, the distance between the first surface 311 and the opening of the first mounting groove 211 of the top cover 210 remains constant from the central axis of the first sealing body 31 toward the retaining wall 32, then gradually increases and then remains constant again. That is, the central region of the first surface 311 near the central axis of the first sealing body 31 protrudes relative to the edge region of the first surface 311 away from the central axis of the first sealing body 31 (i.e., the region where the abutment surface 311a is located).

[0122] In other application scenarios, the central region of the first surface 311 near the central axis of the first sealing body 31 can also be recessed relative to the edge region of the first surface 311 away from the central axis of the first sealing body 31 (i.e., the region where the contact surface 311a is located), so that the contact position between the elastic member 20 and the first sealing member 30 can remain flat.

[0123] In the embodiments of this application, the second surface 312 may be arranged parallel to the first surface 311, and the distance between them remains unchanged. That is, the second surface 312 has a structure corresponding to the first surface 311. In some other embodiments, the structural relationship between the second surface 312 and the first surface 311 may not be limited.

[0124] The retaining wall 32 is connected to the first sealing body 31 and protrudes from the first surface 311 of the first sealing body 31. The retaining wall 32 may be perpendicular to the first sealing body 31. In some other embodiments, the retaining wall 32 may also be inclined to the first sealing body 31. The retaining wall 32 may surround part of the elastic member 20 and form a receiving space with the first sealing body 31 for accommodating the elastic member 20.

[0125] It is understandable that by providing a retaining wall 32 in the first sealing member 30, the retaining wall 32 can serve as a stop position in the first sealing member 30, thereby limiting the movement distance of the elastic member 20 relative to the first sealing member 30, preventing the elastic member 20 from slipping off the first sealing member 30, and thus having a good limiting effect.

[0126] The sidewalls of the first mounting groove 211 of the top cover 210 and the baffle 32 are spaced apart. That is, the second stepped surface 2114 of the top cover 210 and the baffle 32 are spaced apart. The gap area between the outer peripheral surface of the baffle 32 and the second stepped surface 2114 of the top cover 210 forms the first air passage S1. The outer peripheral surface of the baffle 32 is the outer surface surrounding the central axis of the baffle 32. The first air passage S1 is connected to the first sub-air passage S31 of the elastic member 20 for the passage of gas in the power core 320.

[0127] The end of the retaining wall 32 away from the first sealing body 31 is spaced apart from the pressure plate 10. In the thickness direction of the top cover assembly 200, the distance between the end of the retaining wall 32 away from the first sealing body 31 and the surface of the pressure plate 10 facing the elastic member 20 is a first distance d1. The magnitude of the first distance d1 can be used to limit the degree to which the elastic member 20 is compressed.

[0128] It is understandable that when the first sealing element 30 is pushed upward by the air pressure inside the battery cell 320 and compresses the elastic element 20, the end of the baffle 32 away from the first sealing body 31 will approach the surface of the pressure plate 10 facing the elastic element 20, and the first distance d1 will decrease. Therefore, if the first distance d1 is set too large, the baffle 32 can float a greater distance, the first sealing body 31 can float a greater distance, and the elastic element 20 will be compressed to a greater degree. However, if the elastic element 20 is compressed too much, it will undergo plastic deformation and be difficult to return to its original state. Therefore, in the embodiments of this application, the first distance d1 is set in the range of 0.1mm to 0.5mm (including the endpoint values ​​of 0.1mm and 0.5mm). The first distance d1 within this range can ensure the normal venting function of the pressure relief valve assembly 100, and can also avoid the situation where the elastic element 20 is compressed too much and undergoes plastic deformation that is difficult to return to its original state due to the first distance d1 being too large, thus ensuring good reliability.

[0129] The gap between the first sealing element 30 and the pressure plate 10 forms a second air passage S2. The second air passage S2 includes the gap between the end of the baffle 32 away from the first sealing body 31 and the pressure plate 10, as well as the receiving space formed by the baffle 226 and the first sealing body 31. The second air passage S2 is connected to the first sub-air passage S31 of the elastic element 20 and is used to allow gas to pass through the power supply core 320.

[0130] Please refer to Figures 5a, 5b, 13a and 13b. Figure 13a is a structural schematic diagram of the second seal 40 of the pressure relief valve assembly 100 shown in Figure 8 from one angle, and Figure 13b is a structural schematic diagram of the second seal 40 of the pressure relief valve assembly 100 shown in Figure 8 from another angle.

[0131] The second seal 40 is located between the first seal 30 and the bottom wall of the first mounting groove 211 of the top cover 210. Specifically, the second seal 40 is located within the second groove 2112 of the first mounting groove 211 of the top cover 210 and abuts against the bottom wall of the second groove 2112. That is, the second seal 40 abuts against the bottom wall of the first mounting groove 211 of the top cover 210. The side of the second seal 40 facing away from the bottom wall of the first mounting groove 211 of the top cover 210 abuts against the second surface 312 of the first seal 30. There is a gap between the second seal 40 and the inner peripheral wall of the second groove 2112. That is, there is a gap between the second seal 40 and the inner peripheral wall (i.e., the second stepped surface 2114) of the first mounting groove 211. The distance between the outer peripheral surface of the second seal 40 and the second stepped surface 2114 of the top cover 210 can be in the range of 0 to 0.17 mm (including the endpoint value of 0.17 mm, but excluding the endpoint value of 0 mm). The outer peripheral surface of the second seal 40 is the outer surface that surrounds the central axis of the second seal 40.

[0132] Understandably, by setting the distance between the outer peripheral surface of the second seal 40 and the second stepped surface 2114 of the top cover 210 within the aforementioned range, the second seal 40 can be more easily installed in the first mounting groove 211 of the top cover 210. This avoids the second seal 40 from being poorly assembled due to excessively small gaps, resulting in twisting and deformation, which could lead to sealing failure of the pressure relief valve assembly 100. At the same time, it also avoids air leakage due to excessively large gaps.

[0133] The second seal 40 is also located on the outer edge of the air inlet 212 of the top cover 210. Specifically, the second seal 40 is arranged around the air inlet 212 of the top cover 210 in the circumferential direction. The circumferential direction of the air inlet 212 is the direction around the central axis of the air inlet 212. That is, the second seal 40 is annular and surrounds the air inlet 212.

[0134] The second seal 40 can be made of a sealing material with low-temperature resistance. For example, the second seal 40 can be made of ethylene propylene diene monomer (EPDM) rubber.

[0135] The second seal 40 may include an inner ring 41 and an outer ring 42. The inner ring 41 abuts against the bottom wall of the first mounting groove 211 of the first seal 30 and the top cover 210. The inner ring 41 is in line contact with the first seal 30. And / or, the inner ring 41 is in line contact with the first mounting groove 211. The outer ring 42 is connected around the outer edge of the inner ring 41. In the thickness direction (Z direction in the figure), the thickness of the outer ring 42 is less than the thickness of the inner ring 41. The outer ring 42 is also located between the first seal 30 and the bottom wall of the first mounting groove 211 of the top cover 210, and is spaced apart from both the first seal 30 and the bottom wall of the first mounting groove 211 of the top cover 210.

[0136] It is understandable that by making the thickness of the outer ring 42 less than the thickness of the inner ring 41, there can be gaps between the outer ring 42 and the first seal 30, as well as between the outer ring 42 and the bottom wall of the first mounting groove 211 of the top cover 210. These gaps can serve as channels for the gas inside the cell 320 to be discharged to the outside of the battery 300, making the gas flow smoother.

[0137] Specifically, the thickness of the second seal 40 first increases, then decreases, and finally remains constant from near the central axis of the second seal 40 towards away from the central axis of the second seal 40. Therefore, there is a maximum thickness in the inner ring body 41, namely the first thickness T1. At the maximum thickness of the inner ring body 41, the second seal 40 contacts the bottom wall of the first mounting groove 211 of the first seal 30 and / or the top cover 210. That is, there is a line contact between the second seal 40 and the first seal 30, and / or a line contact between the second seal 40 and the bottom wall of the first mounting groove 211 of the top cover 210. Therefore, there are gaps between the second seal 40 and the first seal 30 and the bottom wall of the first mounting groove 211 of the top cover 210 in other parts of the inner ring body 41 and in the outer ring body 42. These gaps can serve as channels for gas in the cell 320 to escape to the outside of the battery 300.

[0138] In some other embodiments, the thickness of the second seal 40 decreases first and then remains constant from near the central axis of the second seal 40 toward away from the central axis of the second seal 40. This can also make the second seal 40 in line contact with the first seal 30, and / or, the second seal 40 in line contact with the bottom wall of the first mounting groove 211.

[0139] It is understandable that if the second seal 40 forms surface contact with the top cover 210 and / or the first seal 30, insufficient flatness of the second seal 40 may cause local depressions, thereby affecting the sealing effect of the pressure relief valve assembly 100 after assembly. Therefore, by making the second seal 40 form line contact with the top cover 210 and / or the first seal 30, the sealing effect of the pressure relief valve assembly 100 can be improved.

[0140] In one possible application scenario, the inner ring 41 of the second seal 40 has a circular cross-sectional shape along the radial direction of the second seal 40, and the maximum thickness of the second seal 40 is equal to the diameter of this circle. The outer ring 42 of the second seal 40 has a rectangular cross-sectional shape along the radial direction of the second seal 40. This can prevent the second seal 40 from moving in its radial direction and improve the structural stability of the second seal 40 after assembly.

[0141] In the embodiments of this application, the portion of the second seal 40 with a constant thickness is the outer ring body 42. The thickness of the outer ring body 42 is a second thickness T2. The second thickness T2 is greater than or equal to 0.4 mm.

[0142] It is understandable that by setting the thickness of the outer ring 42 within the aforementioned range, it is possible to avoid the outer ring 42 being too thin and deformed, which would prevent the outer ring 42 from providing sufficient support when subjected to pressure. This would result in the relative position of the first seal 30 and the top cover 210 becoming unstable, and the outer ring 42 failing to play a positioning and guiding role.

[0143] In the embodiments of this application, the difference between the first thickness T1 and the second thickness T2 of the second seal 40 is greater than or equal to 30% of the first thickness T1. That is, (T1-T2) / T1≥30%.

[0144] It is understandable that by ensuring the thickness of the second seal 40 meets the aforementioned conditions, the thickness difference of the second seal 40 can be kept within a suitable range. This avoids the situation where the thickness difference of the second seal 40 is too small, causing the outer ring 42 to contact the top cover 210 and the first seal 30 when compressed, resulting in an unstable sealing interface and seal failure.

[0145] During battery use, chemical reactions occur inside the battery cell, producing a large amount of gas. If too much gas accumulates, the battery can easily explode. Therefore, an explosion-proof valve assembly is usually installed in the top cover. When the gas pressure inside the battery cell reaches a certain value, the gas will break through the explosion-proof valve assembly and be released to the outside of the battery, thus preventing an explosion due to excessive internal pressure. However, once the explosion-proof valve explodes, it cannot be reused, and the explosion of the explosion-proof valve will also greatly reduce the lifespan of the battery cell.

[0146] Therefore, in the embodiments of this application, by providing a pressure relief valve assembly 100 in the top cover assembly 200, the battery 300 can be repeatedly vented, and the impact on the cell 320 during the venting process can be reduced. Specifically, as shown by the dashed arrow in FIG5b, when a certain amount of gas is generated inside the cell 320, causing the gas pressure formed by the gas entering the air inlet 212 of the top cover 210 to be greater than or equal to the preset threshold of the pressure relief valve assembly 100, the gas will sequentially pass through the air inlet 212 of the top cover 210, the through hole on the second seal 40, and then push up the first seal 30, causing the first seal 30 to compress the elastic member 20. The second connecting portion 23 of the elastic member 20 will move in the radial direction along the first connecting portion 21 under the pressure of the first seal 30, thereby reducing the height of the elastic member 20. As the first seal 30 compresses the elastic member 20, the first seal 30 separates from the second seal 40. The gas enters the first air passage S1 between the first seal 30 and the second step surface 2114 of the top cover 210 through the gap between the second seal 40 and the first seal 30. Then it enters the second air passage S2 between the baffle 32 of the second seal 40 and the pressure plate 10 through the first air passage S1, and then diffuses into the first sub-air passage S31 between the multiple legs 22 of the elastic member 20. Then it passes through the second air passage S2 between the first sealing body 31 of the first seal 30 and the pressure plate 10, the second sub-air passage S32 of the first connecting part 21 of the elastic member 20, and the vent 11 of the pressure plate 10 in sequence, and is finally discharged to the outside of the battery 300.

[0147] Alternatively, as shown by the solid arrow in Figure 5b, unlike the path shown by the dashed arrow in Figure 5b, when the gas passes through the second seal 40, it can also enter the gap between the second seal 40 and the second step surface 2114 of the top cover 210 through the gap between the second seal 40 and the bottom wall of the first mounting groove 211, and then enter the first air passage S1 between the first seal 30 and the second step surface 2114 of the top cover 210.

[0148] When the air pressure at the air inlet 212 is less than the preset threshold of the pressure relief valve assembly 100, the rebound force of the elastic element 20 causes the first seal 30 to press against the second seal 40, keeping the pressure relief valve assembly 100 in a sealed state. The pressure relief valve assembly 100 will stop venting, and this cycle repeats to achieve unidirectional venting of the pressure relief valve assembly 100. For example, the preset threshold can be 0.2 MPa. Of course, in some other embodiments, the preset threshold can also be other values, and this is not strictly limited.

[0149] In summary, when the gas generated inside the battery cell 320 causes the air pressure at the air inlet 212 of the top cover 210 to be greater than or equal to the preset threshold of the pressure relief valve assembly 100, the pressure relief valve assembly 100 will begin to vent gas from the battery 300. When the air pressure at the air inlet 212 of the top cover 210 is less than the preset threshold of the pressure relief valve assembly 100, the pressure relief valve assembly 100 will stop venting gas. That is, the pressure relief valve assembly 100 can repeatedly vent gas from the battery 300, greatly improving the service life of the battery cell 320.

[0150] Furthermore, due to the pressure difference between the inside and outside of the pressure relief valve assembly 100, the pressure relief valve can only be opened by the air pressure inside the battery cell 320, and cannot be opened from the outside of the battery. That is, the pressure relief valve assembly 100 is unidirectional. This prevents substances such as water molecules from the outside of the battery 300 from entering the battery 300 through the pressure relief valve assembly 100 and causing the battery 300 to fail, and further improves the reliability of the battery 300 and increases its service life.

[0151] Furthermore, while the explosion-proof valve assembly F can function when a large amount of gas is generated inside the battery 300, resulting in high gas pressure, it cannot expel the gas when the amount of gas generated inside the cell 320 is insufficient to break through the threshold of the explosion-proof valve 250. Although this small amount of gas will not cause the battery 300 to explode, it can lead to bulging or deformation of the battery 300. The pressure relief valve assembly 100 can control the amount of gas discharged from the cell 320 into the battery 300 by adjusting its opening threshold, thus achieving the purpose of expelling the small amount of gas generated inside the battery 300.

[0152] Please refer to Figures 5a, 5b, 7, and 14a. Figure 14a is a schematic diagram of the lower plastic 220 of the top cover assembly 200 shown in Figure 3 at an angle. The lower plastic 220 is connected to the second surface 2142 of the top cover 210. Part of the lower plastic 220 is located between the upper plastic 230 and the electrode base 242 of the electrode post 240. The lower plastic 220 may be provided with an exhaust port 221. The exhaust port 221 penetrates the lower plastic 220 along its thickness direction. The exhaust port 221 is offset from and communicates with the air inlet 212 of the top cover 210, and is used to allow gas and electrolyte in the battery cell 320 to pass through. That is, gas in the battery cell 320 can enter the air inlet 212 of the top cover 210 through the exhaust port 221.

[0153] The number of exhaust holes 221 can be one or more. When there are multiple exhaust holes 221, they can be spaced apart on the lower plastic 220 along the circumferential direction of the second protrusion 215 of the top cover 210. The circumferential direction of the second protrusion 215 is the direction surrounding the central axis of the second protrusion 215. Each exhaust hole 221 is offset from and connected to the air inlet 212.

[0154] It is understandable that during the process of venting using the pressure relief valve assembly 100, due to the air pressure inside the battery cell 320, electrolyte may easily splash into the interior of the pressure relief valve assembly 100, or even splash out or overflow to the outside of the battery 300 through the pressure relief valve assembly 100.

[0155] Therefore, in the embodiments of this application, when the electrolyte enters the first mounting groove 211 of the top cover 210, the electrolyte can flow into the air inlet 212 of the top cover 210 through the inclined surface on the bottom wall of the first mounting groove 211. Then, it flows through the air inlet 212 of the top cover 210 to the surface of the lower plastic 220 near the top cover 210, and then into the vent 221 of the lower plastic 220, and finally flows back to the battery cell 320 through the vent 221 of the lower plastic 220. This achieves the purpose of returning the electrolyte that has entered the pressure relief valve assembly 100 into the battery cell 320, preventing the electrolyte from splashing out or overflowing to the outside of the battery 300 through the pressure relief valve assembly 100. Furthermore, the staggered connection between the vent 221 and the air inlet 212 increases the path of the electrolyte of the battery cell 320 into the first mounting groove 211 of the top cover 210, reducing the possibility that the electrolyte will directly splash into the air inlet 212 of the top cover 210 after entering the vent 221 of the lower plastic 220, and thus enter the first mounting groove 211 of the top cover 210, thereby increasing the difficulty of the electrolyte penetrating into the pressure relief valve assembly 100.

[0156] In some other embodiments, the exhaust port 221 may also be coaxially arranged and connected with the air inlet port 212 of the top cover 210.

[0157] Please refer to Figures 7, 14a, and 14b. Figure 14b is a structural schematic diagram of the lower plastic 220 of the top cover assembly 200 shown in Figure 3 from another angle. The lower plastic 220 may be provided with a fourth mounting groove 222. The opening of the fourth mounting groove 222 is located on the surface of the lower plastic 220 near the top cover 210. The fourth mounting groove 222 may be formed by recessing from the surface of the lower plastic 220 near the top cover 210 into the interior of the lower plastic 220. The fourth mounting groove 222 is coaxially arranged and connected with the air inlet 212 of the top cover 210, and is also coaxially arranged with the first mounting groove 211 of the top cover 210. The fourth mounting groove 222 can be used to accommodate the second protrusion 215 of the top cover 210. There is a gap between the inner wall of the fourth mounting groove 222 and the second protrusion 215 of the top cover 210. The inner wall of the fourth mounting groove 222 includes the bottom wall and the inner peripheral wall of the fourth mounting groove 222. The inner peripheral wall of the fourth mounting groove 222 is the inner surface surrounding the central axis of the fourth mounting groove 222. Specifically, there is a gap between the bottom wall of the fourth mounting groove 222 and the surface of the first protrusion 225 of the lower plastic 220 facing away from the top cover body 214. There is also a gap between the inner peripheral wall of the fourth mounting groove 222 and the outer peripheral surface of the first protrusion 225 of the lower plastic 220. The outer peripheral surface of the first protrusion 225 of the lower plastic 220 is the outer surface surrounding the central axis of the first protrusion 225. These gap areas cooperate to form a flow channel for the electrolyte to pass through.

[0158] The lower plastic 220 may include a first edge 223a and a second edge 223b. The first edge 223a and the second edge 223b are disposed opposite each other in the width direction (Y direction in the figure) of the lower plastic 220. The distance between the central axis of the fourth mounting groove 222 and the first edge 223a is equal to the distance between the central axis of the fourth mounting groove 222 and the second edge 223b (within the allowable tolerance range). That is, along the width direction of the lower plastic 220, the fourth mounting groove 222 is located at the middle position of the lower plastic 220 (within the allowable tolerance range).

[0159] Understandably, during the charging and discharging process of a battery, the surface of the battery electrodes (such as the anode and cathode) may experience areas lacking electrolyte due to uneven electrolyte flow, forming dry zones. Among these, the electrodes located on the inner ring of the cell are relatively more difficult to rewet with the electrolyte from the outer ring compared to the outer ring of the cell.

[0160] Therefore, in the embodiments of this application, the first mounting groove 211 of the top cover 210 is located at the middle position in the width direction of the top cover 210, and the fourth mounting groove 222 of the lower plastic 220 is located at the middle position in the width direction of the lower plastic 220, so that the vent hole 221 corresponds to the middle inner ring position of the cell 320, thereby redistributing the electrolyte collected from the top cover 210 and the lower plastic 220 to the middle inner ring position of the cell 320, improving the rewetting effect of the electrode at the middle inner ring position of the cell 320.

[0161] The outer edge of the bottom wall of the fourth mounting groove 222 may be provided with the exhaust hole 221 described above. The exhaust hole 221 is connected to the fourth mounting groove 222. That is, a portion of the outer edge of the exhaust hole 221 is connected to a portion of the outer edge of the bottom wall of the fourth mounting groove 222. The exhaust hole 221 and the air inlet 212 of the top cover 210 are connected by a flow channel formed by the gap between the fourth mounting groove 222 and the second protrusion 215 of the top cover 210. When there are multiple exhaust holes 221, the multiple exhaust holes 221 can be spaced apart along the circumferential direction of the fourth mounting groove 222. The circumferential direction of the fourth mounting groove 222 is the direction around the central axis of the fourth mounting groove 222.

[0162] In some other embodiments, the outer edge of the vent 221 can be connected to the inner edge of the bottom wall of the fourth mounting groove 222. That is, the vent 221 penetrates the bottom wall of the fourth mounting groove 222 along the thickness direction of the lower plastic 220. Furthermore, the central axis of the vent 221 is spaced apart from the central axis of the fourth mounting groove 222, which also allows the vent 221 to be misaligned and connected to the air inlet 212 of the top cover 210.

[0163] It is understandable that by setting the vent 221 of the lower plastic 220 on the outer edge of the bottom wall of the fourth mounting groove 222, and by coaxially aligning the air inlet 212 of the top cover 210 with the first mounting groove 211, a staggered arrangement of the vent 221 of the lower plastic 220 and the air inlet 212 of the top cover 210 is achieved. Furthermore, the flow channel between the fourth mounting groove 222 of the lower plastic 220 and the second protrusion 215 of the top cover 210 enables communication between the vent 221 of the lower plastic 220 and the air inlet 212 of the top cover 210. This staggered connection ensures that the gas generated by the cell 320 can be smoothly discharged to the outside of the battery 300, while increasing the path for the electrolyte of the cell 320 to enter the first mounting groove 211 of the top cover 210, reducing the possibility of the electrolyte entering the pressure relief valve assembly 100. Furthermore, the gap between the fourth mounting groove 222 of the lower plastic 220 and the second protrusion 215 of the top cover 210 can serve as a buffer space or a liquid storage space, so that the electrolyte splashed into the fourth mounting groove 222 of the lower plastic 220 needs to accumulate to a certain amount before it can enter the first mounting groove 211 of the top cover 210 through the air inlet 212, further increasing the difficulty of electrolyte penetrating into the pressure relief valve assembly 100.

[0164] The fourth mounting groove 222 may further include a second connecting surface 2221. The second connecting surface 2221 forms at least a portion of the bottom wall of the fourth mounting groove 222. The second connecting surface 2221 is located between the vent 221 and the air inlet 212 of the top cover 210. In the thickness direction of the top cover assembly 200, the distance between the second connecting surface 2221 and the opening of the fourth mounting groove 222 gradually decreases from the end facing the vent 221 towards the end away from the vent 221. That is, the second connecting surface 2221 is an inclined surface.

[0165] In some other embodiments, in the thickness direction of the top cover assembly 200, the distance between the second connecting surface 2221 and the opening of the fourth mounting groove 222 may remain constant and then gradually decrease from the end facing the vent 221 to the end away from the vent 221.

[0166] In some other embodiments, the second connecting surface 2221 may form the entire bottom wall of the fourth mounting groove 222. That is, the second connecting surface 2221 is the bottom wall of the fourth mounting groove 222. In this case, in the thickness direction of the top cover assembly 200, the distance between the second connecting surface 2221 and the opening of the fourth mounting groove 222 gradually decreases from the end facing the vent hole 221 towards the end away from the vent hole 221. Alternatively, in the thickness direction of the top cover assembly 200, the distance between the second connecting surface 2221 and the opening of the fourth mounting groove 222 may remain constant and then gradually decrease from the end facing the vent hole 221 towards the end away from the vent hole 221.

[0167] The embodiments of this application do not limit the proportion of the second connecting surface 2221 occupying the fourth mounting groove 222, as long as the electrolyte splashed into the fourth mounting groove 222 can flow into and back to the battery cell 320 through the inclined surface on the bottom wall of the fourth mounting groove 222.

[0168] Understandably, when the electrolyte enters the first mounting groove 211 of the top cover 210, it can flow through the inclined surface on the bottom wall of the first mounting groove 211 into the air inlet 212 of the top cover 210. Then, it flows through the air inlet 212 into the fourth mounting groove 222 of the lower plastic 220, and then through the inclined surface on the bottom wall of the fourth mounting groove 222 into the vent 221 of the lower plastic 220, finally flowing back into the battery cell 320. The inclined surfaces on the bottom walls of both the first mounting groove 211 of the top cover 210 and the fourth mounting groove 222 of the lower plastic 220 allow the electrolyte splashed into these grooves to flow back into the battery cell 320 more easily, while also increasing the electrolyte flow speed and saving time.

[0169] In one possible application scenario, referring to Figures 7 and 14b, the vent 221 is located at the outer edge of the bottom wall of the fourth mounting groove 222 and communicates with the fourth mounting groove 222. There can be four vents 221. The four vents 221 can be spaced apart along the circumferential direction of the fourth mounting groove 222. The four vents 221 can be located at four equal division points along the circumferential direction of the fourth mounting groove 222. The second connecting surface 2221 forms part of the bottom wall of the fourth mounting groove 222. The second connecting surface 2221 is annular. The outer edge of the second connecting surface 2221 is the outer edge of the bottom wall of the fourth mounting groove 222. In the thickness direction of the top cover assembly 200, the distance between the second connecting surface 2221 and the opening of the fourth mounting groove 222 gradually decreases from the end facing the vent 221 towards the end away from the vent 221. The distance between the bottom wall of the fourth mounting groove 222 and the opening of the fourth mounting groove 222 remains constant and then gradually increases from the direction close to the central axis of the fourth mounting groove 222 towards the direction away from the central axis of the fourth mounting groove 222. That is, the area of ​​the bottom wall of the fourth mounting groove 222 close to its central axis is a plane, and the position of this plane corresponds to the opening of the air inlet 212 of the top cover 210.

[0170] In this application scenario, when the electrolyte of the battery cell 320 splashes into the fourth mounting groove 222 of the lower plastic 220, the electrolyte will flow through the inclined surface on the bottom wall of the fourth mounting groove 222 into the vent hole 221 located on the outer edge of the bottom wall of the fourth mounting groove 222, and then flow back to the battery cell 320, realizing the return of electrolyte.

[0171] In the embodiments of this application, please refer to Figures 7, 14a, 14b, and 14c. Figure 14c is a structural schematic diagram of the lower plastic 220 of the top cover assembly 200 shown in Figure 3 from another angle. The lower plastic 220 may include a lower plastic body 224 and a first protrusion 225. The first protrusion 225 is fixedly connected to the lower plastic body 224 and protrudes from the surface of the top cover 210 relative to the lower plastic body 224. The first protrusion 225 and the lower plastic body 224 can be connected by means such as integral molding to form an integral structure.

[0172] The lower plastic body 224 may include a third surface 2241 and a fourth surface 2242. The third surface 2241 and the fourth surface 2242 are arranged opposite to each other in the thickness direction (Z direction in the figure) of the lower plastic body 224. The third surface 2241 faces away from the battery cell 320. The fourth surface 2242 faces the battery cell 320. The third surface 2241 is connected to the second surface 2142 of the top cover 210. The lower plastic body 224 can be a one-piece structure. In some other embodiments, the lower plastic body 224 can also be a split structure. Specifically, the lower plastic body 224 may include a first part and a second part. The first part and the second part are arranged sequentially in the length direction (X direction in the figure) of the lower plastic body 224. The first part and the second part are detachably connected.

[0173] The first protrusion 225 is connected to the fourth surface 2242 of the lower plastic body 224. In the thickness direction of the lower plastic 220 (Z direction in the figure), the protrusion height of the first protrusion 225 relative to the fourth surface 2242 is a first height H1.

[0174] The lower plastic body 224 and the first protrusion 225 may be provided with the vent 221 and the fourth mounting groove 222 described above. The vent 221 may penetrate the third surface 2241 and the fourth surface 2242 of the lower plastic body 224, and penetrate the side wall of the first protrusion 225 along the thickness direction of the lower plastic 220. The opening of the fourth mounting groove 222 is located on the third surface 2241. The fourth mounting groove 222 may be recessed from the third surface 2241 into the interior of the lower plastic body 224 and the first protrusion 225. The fourth mounting groove 222 is coaxially arranged with the first protrusion 225.

[0175] The lower plastic body 220 may also include a baffle 226. One end of the baffle 226 is connected to the fourth surface 2242 of the lower plastic body 224, and the other end extends away from the top cover 210. The baffle 226 is continuously arranged around the first protrusion 225 in the circumferential direction and is spaced apart from the first protrusion 225. That is, the baffle 226 is annular and surrounds the first protrusion 225. The circumferential direction of the first protrusion 225 is the direction around the central axis of the first protrusion 225. The baffle 226 is located on the side of the vent 221 away from the fourth mounting groove 222. In the thickness direction of the lower plastic body 220, the protrusion height of the baffle 226 relative to the fourth surface 2242 is a second height H2. The second height H2 of the baffle 226 is greater than the first height H1 of the first protrusion 225. The baffle 226 and the lower plastic body 224 can be connected by means such as integral molding to form an integral structure.

[0176] In some other embodiments, the baffle 226 may be located on the side of the vent 221 away from the fourth mounting groove 222, and may be intermittently arranged around the first protrusion 225 in the circumferential direction.

[0177] Understandably, placing a baffle 226 on the side of the lower plastic 220 away from the vent 221 away from the fourth mounting groove 222 can reduce the shaking of the battery cell 320, reduce the possibility of electrolyte splashing into the fourth mounting groove 222 of the lower plastic 220, and thus reduce the risk of electrolyte overflow from the battery 300. Furthermore, setting the height of the baffle 226 to be greater than the height of the first protrusion 225 ensures that when the electrolyte in the fourth mounting groove 222 flows into the battery cell 320 through the vent 221, it can be blocked by the baffle 226, thereby directing the electrolyte vertically into a predetermined position within the battery cell 320, that is, into the inner middle ring position of the battery cell 320.

[0178] The lower plastic 220 may further include a support portion 227. The support portion 227 is connected to the fourth surface 2242 of the lower plastic body 224 and is spaced apart from the baffle 226. In the thickness direction of the lower plastic 220, the protrusion height of the support portion 227 relative to the fourth surface 2242 is a third height H3. The third height H3 of the support portion 227 is greater than the second height H2 of the baffle 226. The support portion 227 can be used to abut against the battery cell 320 and support the battery cell 320, preventing the battery cell 320 from directly contacting the top cover 210 and causing a short circuit.

[0179] The number of support portions 227 can be one or more. When there are multiple support portions 227, the positions of the multiple support portions 227 are different, and the structures can be the same, similar, or different. For example, the number of support portions 227 is three. In the length direction of the lower plastic 220, two of the support portions 227 are located at both ends of the lower plastic 220, and a corresponding explosion-proof hole 217 corresponding to the top cover 210 is provided on the lower plastic 220.

[0180] It is understandable that setting the height of the support 227 to be greater than the height of the baffle 226 can ensure that the baffle 226 does not directly contact the battery cell 320, but has a certain distance from the battery cell 320, thereby reducing the possibility of electrolyte in the battery cell 320 entering the lower plastic 220.

[0181] The lower plastic body 220 may also be provided with a second injection hole 229. Along the length direction of the lower plastic body 220 (X direction in the diagram), the second injection hole 229 may be disposed between the support portion 227 and the second through hole 228b, and located at both ends of the support portion 227, respectively, along with the fourth mounting groove 222. The support portion 227 is located in the lower plastic body 220 at the position corresponding to the explosion-proof hole 217 of the top cover 210. The second injection hole 229 is spaced apart from the support portion 227, the fourth mounting groove 222, and the second through hole 228b. The second injection hole 229 may penetrate the third surface 2241 and the fourth surface 2242. That is, the second injection hole 229 penetrates the lower plastic body 224 along its thickness direction. The second injection hole 229 can be used to communicate with the first injection hole 218 of the top cover 210 and to inject electrolyte into the battery cell 320.

[0182] Referring to Figures 7, 14a, 14b, and 14c, the lower plastic 220 may have a second groove 228a and a second through hole 228b. The opening of the second groove 228a is located on the surface of the lower plastic 220 opposite to the top cover 210. That is, the opening of the second groove 228a is located on the fourth surface 2242. The second groove 228a can be formed by recessing into the lower plastic 220 from the fourth surface 2242. The second groove 228a can be used to install the pole base 242 of the pole 240. The second through hole 228b is coaxially arranged with and connected to the second groove 228a. The second through hole 228b can penetrate the third surface 2241 and the bottom wall of the second groove 228a along the thickness direction of the lower plastic 220. That is, one end of the second through hole 228b is located on the third surface 2241, and the other end is located on the bottom wall of the second groove 228a. The second through hole 228b communicates with the first through hole 216b of the top cover 210. The second through hole 228b allows the pole post 240 to pass through and accommodates the fourth body 2414 of the pole post 240. The inner surface of the second through hole 228b can be spaced apart from the outer peripheral surface of the fourth body 2414 of the pole post 240. The outer peripheral surface of the fourth body 2414 of the pole post 240 is the outer surface surrounding the central axis of the fourth body 2414. The inner surface of the second through hole 228b is the surface surrounding the central axis of the second through hole 228b.

[0183] There can be two second grooves 228a, which are spaced apart along the length of the lower plastic 220. Each second groove 228a can be used to mount the electrode base 242 of an electrode post 240. There can also be two second through holes 228b, which are spaced apart along the length of the lower plastic 220 and coaxially connected to the two second grooves 228a. One of the second through holes 228b is for the positive electrode post to pass through. The other second through hole 216b is for the negative electrode post to pass through.

[0184] In embodiments of this application, the lower plastic 220 may include a second boss 228c. The second boss 228c is connected to the third surface 2241 of the lower plastic body 224 and protrudes relative to the third surface 2241. The second boss 228c and the lower plastic body 224 can be connected by means such as integral molding to form an integral structure. The second boss 228c is located in the first groove 216a of the top cover 210. The second boss 228c is separated from the bottom wall of the first groove 216a of the top cover 210 by the upper plastic 230. The surface of the second boss 228c facing away from the top cover body 214 abuts against the sixth surface 232 of the upper plastic 230. The connection between the second boss 228c of the lower plastic 220 and the first groove 216a of the top cover 210 can help align and connect the lower plastic 220 and the top cover 210, improving the assembly efficiency of the top cover assembly 200 and the battery 300.

[0185] For example, there may be two second protrusions 228c, which are spaced apart along the length of the lower plastic 220. Each second protrusion 228c is located within a first groove 216a of a top cover 210.

[0186] The lower plastic body 224 and the second boss 228c may be provided with the second through hole 228b and the second groove 228a as described above. The opening of the second groove 228a may be located on the fourth surface 2242. The second groove 228a may be recessed into the lower plastic 220 from the fourth surface 2242. The bottom wall of the second groove 228a may be located within the lower plastic body 224, and the second through hole 228b may penetrate the second boss 228c and at least a portion of the lower plastic body 224 along the thickness direction of the lower plastic 220. Alternatively, the bottom wall of the second groove 228a may be located within the second boss 228c, and the second through hole 228b may penetrate a portion of the second boss 228c along the thickness direction of the lower plastic 220. Alternatively, the bottom wall of the second groove 228a may be flush with the third surface 2241, and the second through hole 228b may penetrate the second boss 228c along the thickness direction of the lower plastic 220.

[0187] Please refer to Figures 7 and 15. Figure 15 is a schematic diagram of one structure of the upper plastic 230 of the top cover assembly 200 shown in Figure 3. The upper plastic 230 may include a fifth surface 231 and a sixth surface 232. The fifth surface 231 and the sixth surface 232 are arranged opposite to each other in the thickness direction (Z direction shown in the figure) of the upper plastic 230. The fifth surface 231 faces away from the battery cell 320. The sixth surface 232 faces the battery cell 320. The fifth surface 231 abuts against the surface of the second body 2412 of the electrode post 240 near the electrode post base 242. The sixth surface 232 abuts against the surface of the fourth body 2414 of the electrode post 240 facing away from the electrode post base 242.

[0188] The upper plastic 230 may have a third through hole 233. The third through hole 233 can penetrate the fifth surface 231 and the sixth surface 232. That is, the third through hole 233 penetrates the upper plastic 230 along the thickness direction of the upper plastic 230. The third through hole 233 of the upper plastic 230 can be coaxially arranged and connected with the first through hole 216b of the top cover 210 and the second through hole 228b of the lower plastic 220. The third through hole 233 is used for the pole post 240 to pass through and for accommodating the third body 2413 of the pole post 240. The inner surface of the third through hole 233 can abut against the outer peripheral surface of the third body 2413 of the pole post 240. The inner surface of the third through hole 233 is the surface surrounding the central axis of the third through hole 233. The outer peripheral surface of the third body 2413 is the outer surface surrounding the central axis of the third body 2413.

[0189] The number of upper plastic components 230 can be two. The two upper plastic components 230 are spaced apart along their length (X direction in the diagram). One upper plastic component 230 is mounted on a positive terminal. The other upper plastic component 230 is mounted on a negative terminal. The number of third through holes 233 can also be two, and the two third through holes 233 can be spaced apart along the length of the upper plastic components 230. One third through hole 233 is used for the positive terminal to pass through. The other third through hole 233 is used for the negative terminal to pass through.

[0190] The upper plastic 230 may be provided with a second slot 234. The opening of the second slot 234 is located on the outer peripheral surface of the upper plastic 230. The outer peripheral surface of the upper plastic 230 is the outer surface surrounding the central axis of the upper plastic 230. The second slot 234 may be formed by recessing from the outer peripheral surface of the upper plastic 230 into the interior of the upper plastic 230. The second slot 234 is arranged around the third through hole 233 in the circumferential direction. The circumferential direction of the third through hole 233 is the direction surrounding the central axis of the third through hole 233. The bottom wall of the second slot 234 is spaced apart from and parallel to the inner surface of the third through hole 233. That is, the second slot 234 is annular and surrounds the third through hole 233. The second slot 234 may include a first side surface 234a and a second side surface 234b. The first side surface 234a and the second side surface 234b may be arranged opposite each other in the thickness direction of the upper plastic 230. The first side surface 234a is close to the fifth surface 231. The second side surface 234b is close to the sixth surface 232. The second slot 234 can be used to install part of the top cover 210. The bottom wall of the second slot 234 abuts against the inner surface of the first through hole 216b of the top cover 210. The first side surface 234a abuts against the surface of the first boss 216c of the top cover 210 facing away from the top cover body 214. The second side surface 234b abuts against the bottom wall of the first groove 216a of the top cover 210.

[0191] For example, there may be two second slots 234, which are spaced apart along the length of the upper plastic 230. Each second slot 234 is connected to a portion of the top cover 210.

[0192] It is understood that by providing a second groove 234 recessed in the radial direction of the upper plastic 230 within the upper plastic 230 and connecting the second groove 234 with the top cover 210, the installation stability of the upper plastic 230 and the top cover 210 can be increased, preventing the top cover 210 from moving in the thickness direction of the top cover assembly 200.

[0193] Please refer to Figures 7 and 16. Figure 16 is a schematic diagram of one structure of the pole post 240 of the top cover assembly 200 shown in Figure 3. The pole post 240 is mounted on the upper plastic 230, the top cover 210, and the lower plastic 220. The opposite ends of the pole post 240 protrude from the fifth surface 231 of the upper plastic 230 and the fourth surface 2242 of the lower plastic 220, respectively. Specifically, the pole post 240 may include a pole post body 241 and a pole post base 242. The pole post base 242 is located on the side of the top cover 210 near the lower plastic 220. One end of the pole post body 241 is fixedly connected to the pole post base 242. The pole post body 241 passes through the second through hole 228b of the lower plastic 220, the first through hole 216b of the top cover 210, and the third through hole 233 of the upper plastic 230. The other end of the pole post body 241 extends out of the upper plastic 230.

[0194] The pole post body 241 may include a first body 2411, a second body 2412, a third body 2413, and a fourth body 2414. The first body 2411, second body 2412, third body 2413, and fourth body 2414 are sequentially connected and coaxially arranged. One end of the fourth body 2414 is connected to the pole post base 242. The third body 2413 is connected between the fourth body 2414 and the second body 2412. The first body 2411 is connected to the surface of the second body 2412 facing away from the third body 2413. The pole post base 242 and the first body 2411, second body 2412, third body 2413, and fourth body 2414 of the pole post 240 can be a single integrated structure. The cross-sectional width of the first body 2411 along the thickness direction (Z direction in the figure) of the pole post 240 is smaller than the cross-sectional width of the second body 2412 along the thickness direction of the pole post 240. The cross-sectional width of the third main body 2413 along the thickness direction of the pole post 240 is smaller than the cross-sectional width of the second main body 2412 along the thickness direction of the pole post 240, and also smaller than the cross-sectional width of the fourth main body 2414 along the thickness direction of the pole post 240. The cross-sectional width of the pole post base 242 along the thickness direction of the pole post 240 is larger than the cross-sectional width of the pole post main body 241 (including the first main body 2411, the second main body 2412, the third main body 2413 and the fourth main body 2414) along the thickness direction of the pole post 240.

[0195] Understandably, dividing the electrode post body 241 into four parts of different sizes allows for better installation of the upper plastic 230, top cover 210, and lower plastic 220 into their corresponding parts, preventing misalignment. Furthermore, the electrode post base 242 is larger than the electrode post body 241, effectively preventing the electrode post 240 from slipping off.

[0196] In the embodiments of this application, the first body 2411 and the second body 2412 of the pole post 240 protrude from the fifth surface 231 of the upper plastic 230. The surface of the second body 2412 near the pole post base 242 abuts against the fifth surface 231 of the upper plastic 230. The third body 2413 of the pole post 240 is located within the third through hole 233 of the upper plastic 230 and the first through hole 216b of the top cover 210, and is separated from the top cover 210 by the upper plastic 230. The outer peripheral surface of the third body 2413 abuts against the inner surface of the third through hole 233 of the upper plastic 230. The fourth body 2414 of the pole post 240 is located within the second through hole 228b of the lower plastic 220. There is a gap between the outer peripheral surface of the fourth body 2414 and the inner surface of the second through hole 228b of the lower plastic 220. The surface of the fourth main body 2414 facing away from the pole base 242 abuts against the sixth surface 232 of the upper plastic 230. Part of the pole base 242 of the pole 240 is located in the second through hole 228b of the lower plastic 220, and part of the pole base 242 protrudes relative to the fourth surface 2242 of the lower plastic 220.

[0197] 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 pressure relief valve assembly, the pressure relief valve assembly being connected to a top cover, the top cover having a communicating first mounting groove and an air inlet, wherein, The pressure relief valve assembly includes a pressure plate, an elastic element, a first seal, and a second seal arranged sequentially in the first mounting groove. The elastic element elastically abuts against the pressure plate and the first seal. The second seal is located between the first seal and the bottom wall of the first mounting groove. The second seal is also located at the outer edge of the air inlet. The gap area between the first seal and the side wall of the first mounting groove forms a first air passage, the gap area between the first seal and the pressure plate forms a second air passage, the elastic element is provided with a third air passage, the pressure plate is provided with an air outlet, and the air outlet connects the interior of the pressure relief valve assembly and the exterior of the pressure relief valve assembly. When the air pressure at the air inlet is less than the preset threshold of the pressure relief valve assembly, the first seal is pressed against the second seal by the elastic member to seal the air inlet. When the air pressure at the air inlet is greater than or equal to the preset threshold of the pressure relief valve assembly, the first seal is pushed by the gas at the air inlet and separates from the second seal. The air inlet, the first air passage, the second air passage, the third air passage and the air outlet are connected in sequence to form a gas channel for the gas at the air inlet to pass through.

2. The pressure relief valve assembly according to claim 1, wherein, The pressure plate includes a pressure plate body and a flange. The pressure plate body is provided with the air vent. The flange is located on the side of the pressure plate body facing the elastic member. One end of the flange is connected to the outer edge of the air vent. The other end of the flange is projected into the pressure plate body along the thickness direction of the pressure plate. The flange is bent relative to the pressure plate body and cooperates with the pressure plate body to form a first groove. Part of the elastic member is located in the first groove and abuts against the pressure plate body and the flange.

3. The pressure relief valve assembly according to claim 2, wherein, The pressure plate body has a second mounting groove recessed on the surface facing the elastic element. The second mounting groove communicates with the first slot, and part of the elastic element is located in the second mounting groove.

4. The pressure relief valve assembly according to claim 2, wherein, The elastic element includes a first connecting portion and a plurality of legs. At least a portion of the first connecting portion is located within the first slot. The plurality of legs are spaced apart in the circumferential direction of the first connecting portion. Each leg includes a first connecting end and a second connecting end. The first connecting end is fixedly connected to the outer edge of the first connecting portion. The second connecting end abuts against the first sealing element. The second connecting end is capable of moving relative to the first sealing element in the radial direction of the first connecting portion.

5. The pressure relief valve assembly according to claim 4, wherein, The elastic element further includes a second connecting portion, which is annular. The second connecting end is fixedly connected to the inner edge of the second connecting portion. The second connecting portion and the first connecting portion are spaced apart in the thickness direction of the elastic element and abut against the first sealing element. The second connecting portion is capable of moving relative to the first sealing element in the radial direction of the first connecting portion.

6. The pressure relief valve assembly according to claim 4 or 5, wherein, The third air passage includes a first sub-air passage and a second sub-air passage. The first sub-air passage is the gap area between two adjacent legs and is connected to the first air passage. The second sub-air passage is a through hole that penetrates the first connecting part along the thickness direction of the first connecting part and is connected to the air outlet.

7. The pressure relief valve assembly according to any one of claims 1-5, wherein, The elastic element and the first sealing element are in line contact.

8. The pressure relief valve assembly according to any one of claims 1-5, wherein, The first sealing element includes a first sealing body and a retaining wall; The first sealing body includes a first surface and a second surface, which are disposed opposite to each other in the thickness direction of the first sealing body. The first surface abuts against the elastic element, and the second surface abuts against the second sealing element. The baffle wall is connected around the outer edge of the first sealing body and protrudes relative to the first surface. The baffle wall also surrounds part of the elastic element. The end of the baffle wall away from the first sealing body is spaced apart from the pressure plate. The gap area between the outer peripheral surface of the baffle wall and the side wall of the first mounting groove forms the first air passage.

9. The pressure relief valve assembly according to claim 8, wherein, The portion of the first surface that contacts the elastic element is a plane.

10. The pressure relief valve assembly according to any one of claims 1-5, wherein, The second seal is in line contact with the first seal, and / or the second seal is in line contact with the first mounting groove.

11. The pressure relief valve assembly according to any one of claims 1-5, wherein, The second sealing element includes an inner ring body and an outer ring body. The inner ring body abuts against the bottom wall of the first sealing element and the first mounting groove. The outer ring body surrounds and connects to the outer edge of the inner ring body. The thickness of the outer ring body is less than the thickness of the inner ring body.

12. A top cover assembly, wherein, The top cover assembly includes a top cover and a pressure relief valve assembly as described in any one of claims 1-11, wherein the top cover has a first mounting groove and an air inlet that are connected in communication, and the pressure relief valve assembly is located in the first mounting groove and covers the air inlet.

13. The top cover assembly according to claim 12, wherein, The first mounting groove includes a first groove and a second groove, which are coaxially arranged. The cross-sectional width of the first groove along the thickness direction of the top cover is greater than the cross-sectional width of the second groove along the thickness direction of the top cover. A first stepped surface is formed at the connection between the first groove and the second groove. The pressure plate is located in the first groove and abuts against the first stepped surface. The elastic element is located in the first groove and the second groove. The first sealing element and the second sealing element are both located in the second groove.

14. A battery, wherein, The battery includes a cell, a housing, and a top cover assembly as described in claim 12 or 13, 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.

15. An electrical appliance, wherein, The electrical device includes the battery as described in claim 14.

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