Top cover assembly, battery and electrical equipment

Abstract

The present application provides a top cover assembly, a battery, and an electrical device. The assembly comprises a lower plastic and a support member; the lower plastic comprises a connected lower plastic body and a central boss, the lower plastic body comprises a first surface and a second surface, the central boss protrudes relative to the second surface, and the central boss comprises a bottom surface and a first side surface connected between the lower plastic and the second surface; the lower plastic is provided with a mounting groove and a plurality of first exhaust holes spaced apart, the mounting groove is located between the lower plastic body and the central boss, the first exhaust holes are located between the first side surface and the bottom surface, and at least one first exhaust hole is connected to the mounting groove; the support member is located in the mounting groove and supported between the lower plastic and the top cover; the mounting groove comprises a first side wall forming a first air channel with the support member, the first air channel is connected to at least one first exhaust hole, and the dimension of the first air channel in the length direction of the lower plastic gradually decreases from the opening of the mounting groove toward the bottom wall. The technical solution of the present application can solve the problem of difficulty in exhausting when the battery cell is in thermal runaway.

Description

Technical Field

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

[0002] With the development of clean energy, recyclable batteries are becoming increasingly popular. A battery consists of an electrode assembly, a casing, and a top cover assembly. The electrode assembly is located within the housing formed by the casing and the top cover assembly. The top cover assembly includes a top cover, a lower plastic, and an explosion-proof valve, with the top cover and lower plastic stacked together. When a battery cell in an electrode assembly experiences thermal runaway, the lower plastic can melt, causing the cell to float. This blocks the exhaust duct in the top cover, preventing the gas inside the cell from being effectively exhausted. This can lead to excessive pressure inside the cell, causing an explosion. Summary of the Invention

[0003] The embodiments of the present application provide a top cover assembly, a battery, and an electrical device, which can solve the problem that the gas inside the battery cell cannot be effectively exhausted when the battery cell thermally runs away.

[0004] In a first aspect, the present application provides a top cover assembly, the top cover assembly comprising a lower plastic and a support member;

[0005] The top cover assembly includes a top cover, a lower plastic and a support member;

[0006] The lower plastic includes a lower plastic body and a central boss, the lower plastic body and the top cover are stacked, the lower plastic body includes a first surface and a second surface, the first surface and the second surface are arranged opposite to each other in the thickness direction of the lower plastic body, the central boss is connected to the lower plastic body and protrudes relative to the second surface, the central boss includes a bottom surface and a first side surface, the bottom surface and the second surface are spaced apart in the thickness direction of the lower plastic, the first side surface is connected between the second surface and the bottom surface, and the first side surface is one of the two side surfaces of the central boss spaced apart along the length direction of the lower plastic;

[0007] The lower plastic is provided with a mounting groove and a plurality of first exhaust holes. The mounting groove is located between the lower plastic body and the central boss, and the opening of the mounting groove is located on the first surface. The plurality of first exhaust holes are arranged at intervals along the width direction of the lower plastic. Each first exhaust hole is located on the first side surface and the bottom surface, and penetrates the central boss along the length direction and the thickness direction of the lower plastic. At least one of the plurality of first exhaust holes is communicated with the mounting groove.

[0008] The support member is located in the mounting groove, and in the thickness direction of the top cover assembly, one side of the support member abuts against the bottom wall of the mounting groove, and the other side of the support member is used to support the top cover;

[0009] The mounting groove includes a first side wall, which is a side wall of the mounting groove along the length direction of the lower plastic. A first air duct is formed between the first side wall and the support member. The first air duct is connected to at least one first exhaust hole among the multiple first exhaust holes. The size of the first air duct in the length direction of the lower plastic gradually decreases from the opening of the mounting groove toward the bottom wall of the mounting groove.

[0010] Understandably, when a battery cell experiences thermal runaway, the explosion-proof valve installed on the top cover can easily break open, and the flammable gases and sparks generated by the battery cell can be released through the explosion-proof valve into the air outside the battery. These gases and sparks then react with the oxygen in the air, causing the battery cell to ignite. Due to the high temperature of the battery cell during thermal runaway, the lower plastic is easily melted by the high temperature, making it difficult for the lower plastic to act as a stop when the battery cell floats under the action of the electrolyte and air pressure. This can bring the battery cell and the top cover closer together, or even cause them to touch. This increases the amount of flammable gases and sparks that splash out of the battery, further increasing the likelihood of these gases and sparks coming into contact with oxygen in the air and exacerbating the risk of battery cell fire.

[0011] Therefore, in the implementation of this application, by providing an insulating and electrolyte-corrosion-resistant support member between the lower plastic and the top cover, the top cover can be effectively supported, preventing the lower plastic from deforming at high temperatures in the early stages of thermal runaway, thereby losing its restraint on the battery cell. Furthermore, even if thermal runaway causes the lower plastic to melt, the support member can still support the top cover and the battery cell, preventing the battery cell from floating close to the top cover, thereby suppressing the phenomenon of sparks splashing out of the explosion-proof valve and reducing the risk of battery cell fire.

[0012] Furthermore, by providing a plurality of first exhaust holes on the side of the central boss, the number of exhaust channels on the lower plastic can be increased, thereby improving the exhaust rate of the gas inside the battery cell when the battery cell thermal runaway occurs, thereby improving the safety performance of the top cover assembly.

[0013] In addition, a first air channel is formed between the support member and the first sidewall of the mounting slot, and the first air channel is connected to at least one of the plurality of first exhaust holes. This provides a passage for gas that enters the mounting slot through the first exhaust hole, thereby preventing the support member from blocking the first exhaust hole of the central boss, which could cause poor exhaust and increased air pressure, leading to battery cell explosion. This effectively exhausts gas from within the battery cell, improving exhaust reliability.

[0014] Furthermore, by gradually decreasing the length of the first air passage along the length of the lower plastic from the opening of the mounting slot toward the bottom wall of the mounting slot, the spacing between the support member and the first sidewall of the mounting slot can be designed to be narrower at the bottom and wider at the top. The narrower bottom design reduces any movement of the support member after it is installed in the lower plastic, while the wider top design ensures that there is a channel for exhaust in the area where the support member is located, improving the reliability of exhaust from the lower plastic.

[0015] In a possible implementation manner, the support member includes a main body and a first fixing portion;

[0016] The main body includes a first connecting surface, which is a surface of the main body in the width direction of the lower plastic. The first connecting surface includes a first sub-surface and two second sub-surfaces. The first sub-surface is connected between the two second sub-surfaces. In the thickness direction of the lower plastic, one second sub-surface, one first sub-surface, and another second sub-surface are arranged in sequence.

[0017] The first fixing portion is connected to one of the first sub-surfaces. The first fixing portion and two of the second sub-surfaces on the same side are respectively surrounded to form two first avoidance grooves. In the two first avoidance grooves, each of the first avoidance grooves is communicated with the first air duct.

[0018] In a possible implementation manner, the support member further includes a second fixing portion;

[0019] The main body further includes a second connecting surface, the second connecting surface and the second connecting surface are arranged opposite to each other in the width direction of the blister plastic, the second connecting surface includes a third sub-surface and two fourth sub-surfaces, the third sub-surface is connected between the two fourth sub-surfaces, and in the thickness direction of the lower plastic, one fourth sub-surface, one third sub-surface and another fourth sub-surface are arranged in sequence;

[0020] The second fixing portion is connected to one of the third sub-surfaces, and the second fixing portion and the two fourth sub-surfaces on the same side are respectively surrounded to form two second avoidance grooves. In the two second avoidance grooves, each of the second avoidance grooves is communicated with the first air duct.

[0021] In a possible embodiment, the main body further includes a first transition surface and a second transition surface, wherein the first transition surface and the second transition surface are both connected between the first connecting surface and the second connecting surface and are arranged opposite to each other in the length direction of the lower plastic;

[0022] Any connection between the first fixing portion and the first transition surface and the second transition surface is a cambered transition; and / or,

[0023] Any connection between the second fixing portion and the first transition surface or the second transition surface is a cambered transition.

[0024] In a possible embodiment, the central boss further includes a second side surface, the second side surface is connected between the second surface and the bottom surface, and is spaced apart from the first side surface in the length direction of the lower plastic;

[0025] The lower plastic is provided with a plurality of second exhaust holes, which are spaced apart along the width direction of the lower plastic. Each second exhaust hole is located on the second side surface and the bottom surface, and passes through the central boss along the length direction and the thickness direction of the lower plastic. At least one of the plurality of second exhaust holes is connected to the mounting groove.

[0026] The mounting groove also includes a second side wall, which is arranged opposite to the first side wall in the longitudinal direction of the lower plastic. A second air duct is formed between the second side wall and the support member, and the second air duct is connected to at least one second exhaust hole among the plurality of second exhaust holes. The size of the second air duct in the longitudinal direction of the lower plastic gradually decreases from the opening of the mounting groove toward the bottom wall of the mounting groove. The second air duct is connected to each of the first avoidance grooves and / or each of the second avoidance grooves.

[0027] In a possible implementation, the mounting groove further includes a third side wall and a fourth side wall, wherein the third side wall and the fourth side wall are both connected between the first side wall and the second side wall, and the third side wall and the fourth side wall are arranged opposite to each other in the width direction of the lower plastic;

[0028] A third air channel is formed between the third side wall and the support member, and the third air channel is connected to both the first air channel and the second air channel; and / or,

[0029] A fourth air channel is formed between the fourth side wall and the support member, and the fourth air channel is communicated with both the first air channel and the second air channel.

[0030] In one possible embodiment, the lower plastic is provided with a cavity, the cavity being located between the lower plastic body and the central boss, and the opening of the cavity being located on the first surface. The lower plastic further comprises a partition, the partition being connected to the bottom wall of the cavity and two opposite side walls of the cavity along the length direction of the lower plastic, and the partition being capable of cooperating with the inner wall of the cavity to separate the mounting groove within the cavity;

[0031] A buckle is provided at one end of the partition away from the bottom wall of the cavity, and at least part of the buckle is located in the first avoidance groove close to the top cover among the two first avoidance grooves, and the buckle is used to fix the support member.

[0032] In a possible embodiment, the top cover is provided with an explosion-proof hole, which passes through the top cover along the thickness direction of the top cover, and is used to connect to an explosion-proof valve;

[0033] In the thickness direction of the top cover assembly, the projection of the support member on the top cover covers a portion of the explosion-proof hole; or,

[0034] In the thickness direction of the top cover assembly, the projection of the support member on the top cover is spaced apart from the explosion-proof hole.

[0035] In one possible embodiment, the lower plastic is further provided with a plurality of third exhaust holes, and the plurality of third exhaust holes are arranged at intervals along the width direction of the lower plastic, and each of the third exhaust holes passes through the central boss along the thickness direction of the lower plastic, and at least one of the plurality of third exhaust holes is connected to the mounting groove.

[0036] In a possible embodiment, the lower plastic further includes a first edge boss, the first edge boss being connected to the lower plastic body and protruding relative to the second surface, and the first edge boss being located at one end of the lower plastic body in the longitudinal direction;

[0037] The first edge boss is provided with a plurality of fourth exhaust holes, which are spaced apart in the width direction of the lower plastic and arranged opposite to the plurality of first exhaust holes in the length direction of the lower plastic. Each of the fourth exhaust holes passes through the first edge boss along the length direction of the lower plastic.

[0038] In a possible embodiment, the lower plastic further includes a second edge boss, the second edge boss being connected to the lower plastic body and protruding relative to the second surface, and the second edge boss being located at the other end of the lower plastic body in the longitudinal direction;

[0039] The second edge boss is provided with a plurality of fifth exhaust holes, which are spaced apart in the width direction of the lower plastic and arranged opposite to the plurality of second exhaust holes in the length direction of the lower plastic. Each of the fifth exhaust holes passes through the second edge boss along the length direction of the lower plastic.

[0040] In one possible embodiment, the lower plastic is provided with a first hole group. In the length direction of the lower plastic, the first hole group is located on one side of the central boss and is arranged adjacent to the central boss. The first hole group includes a sixth exhaust hole and a plurality of seventh exhaust holes. The sixth exhaust hole and the plurality of seventh exhaust holes both penetrate the lower plastic along the thickness direction of the lower plastic. The plurality of seventh exhaust holes are arranged in at least two first annular rings in a direction outward from a center line of the sixth exhaust hole in the width direction of the lower plastic and are sequentially spaced outside the sixth exhaust hole. In the at least two first annular rings, the plurality of seventh exhaust holes located in the same first annular ring are spaced apart.

[0041] In the thickness direction of the top cover assembly, the projection of the explosion-proof hole on the lower plastic body at least covers a portion of the projection of the central boss on the lower plastic body and a portion of the projection of the plurality of seventh exhaust holes on the lower plastic body.

[0042] In one possible embodiment, the dimension of each first annular ring along the width direction of the lower plastic is greater than the dimension of each first annular ring along the length direction of the lower plastic, and the dimension of each first annular ring along the length direction of the lower plastic first gradually increases and then gradually decreases from one side of the width direction of the lower plastic to the other side of the width direction of the lower plastic.

[0043] In one possible embodiment, the lower plastic further includes a convex portion, the convex portion being connected to both the lower plastic body and the central boss and protruding relative to the second surface, and the sixth exhaust hole and the plurality of seventh exhaust holes are both provided in the convex portion and penetrate the convex portion along the thickness direction of the lower plastic;

[0044] The lower plastic is also provided with an air relief groove, the opening of the air relief groove is located on the first surface, and the air relief groove is recessed from the first surface toward the direction of the convex portion and the central boss. The air relief groove is also connected to the mounting groove, the sixth exhaust hole, and the multiple seventh exhaust holes. In the thickness direction of the top cover assembly, the projection of the air relief groove on the top cover can cover the explosion-proof hole.

[0045] In a second aspect, the present application also provides a battery, which includes an electrode assembly, a shell and a top cover assembly as described above, wherein the top cover assembly is connected to the shell and is arranged together with the shell to form a receiving space, and the electrode assembly is located in the receiving space.

[0046] In a third aspect, the present application further provides an electrical device, which includes the battery as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is a schematic structural diagram of an energy storage system provided in an embodiment of the present application;

[0048] Figure 2 This is a schematic structural diagram of a battery provided in an embodiment of the present application;

[0049] Figure 3 is a schematic structural diagram of a top cover assembly provided in an embodiment of the present application;

[0050] Figure 4 yes Figure 3 A schematic diagram of the exploded structure of the top cover assembly shown;

[0051] Figure 5 yes Figure 3 A schematic structural diagram of an angle of the top cover of the top cover assembly shown;

[0052] Figure 6 yes Figure 3 A schematic structural diagram of the top cover of the top cover assembly shown in FIG.

[0053] Figure 7 It is along Figure 3 A schematic cross-sectional view of a partial structure obtained by cutting along the cutting line AA shown;

[0054] Figure 8 yes Figure 3 A schematic structural diagram of the lower plastic portion of the top cover assembly at an angle is shown;

[0055] Figure 9 yes Figure 3 A schematic structural diagram of the lower plastic portion of the top cover assembly from another angle;

[0056] Figure 10a yes Figure 8 A schematic diagram of a partial structure of the lower plastic at an angle shown;

[0057] Figure 10b It is along Figure 8 The schematic cross-sectional view of the partial structure of the lower plastic obtained by cutting along the cutting line BB shown;

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

[0059] Figure 12 It is along Figure 3 A schematic cross-sectional view of a portion of the top cover assembly obtained by cutting along the cutting line CC shown;

[0060] Figure 13 It is along Figure 3A schematic cross-sectional view of a portion of the top cover assembly obtained by cutting along the cutting line EE shown;

[0061] Figure 14 yes Figure 3 A structural schematic diagram of a partial structure of the top cover assembly shown;

[0062] Figure 15 yes Figure 3 A schematic structural diagram of the support member of the top cover assembly at one angle is shown.

[0063] Reference numerals:

[0064] Energy storage system 400, electric energy conversion device 410, first user load 420, second user load 430, electrical equipment 300, battery 200, top cover assembly 100, shell 210, electrode assembly 220, top cover 10, upper plastic 20, lower plastic 30, pole 40, connecting piece 51, sealing ring 52, pressure ring 53, limiter 54, support member 60, thermal insulation sheet 70, explosion-proof valve assembly 80, third surface 101, fourth Surface 102, explosion-proof hole 11, mounting platform 12, groove 13, explosion-proof valve 81, explosion-proof valve protection sheet 82, lower plastic body 31, central boss 32, cavity 33, first surface 311, second surface 312, bottom surface 321, first side surface 322, second side surface 323, first exhaust hole 324, second exhaust hole 325, third exhaust hole 326, partition 34, buckle 341, guide slope 342, mounting groove 35, first Side wall 351, second side wall 352, third side wall 353, fourth side wall 354, first hole group 36, second hole group 37, sixth exhaust hole 361, seventh exhaust hole 362, first annular ring T1, eighth exhaust hole 371, ninth exhaust hole 372, second annular ring T2, convex portion 301, air relief groove 302, first edge boss 38, second edge boss 39, fourth exhaust hole 381, fifth exhaust hole 391, first air channel S 1. Second air channel S2, third air channel S3, fourth air channel S4, main body 61, first fixing portion 62, second fixing portion 63, first supporting surface 611, second supporting surface 612, first connecting surface 613, second connecting surface 614, first transition surface 615, second transition surface 616, first sub-surface 6131, second sub-surface 6132, third sub-surface 6141, fourth sub-surface 6142, first avoidance groove 64, second avoidance groove 65. DETAILED DESCRIPTION

[0065] For ease of understanding, the terms involved in the embodiments of the present application are first explained.

[0066] And / or: It is just a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0067] Multiple: refers to two or more than two.

[0068] Connection: should be understood in a broad sense. For example, A and B are connected, which can be either directly connected or indirectly connected through an intermediary.

[0069] The specific implementation of the present application will be clearly described below with reference to the accompanying drawings.

[0070] Embodiments of the present application provide a top cover assembly, a battery, and an electrical device.

[0071] Because the energy people need is highly temporal and spatially dependent, rational energy utilization and improved efficiency require a medium or device that can store one form of energy in the same form or convert it into another, allowing it to be released in a specific form based on future application needs. Currently, green electricity generation generally relies on photovoltaics, wind power, and hydropower. However, wind and solar power are often intermittent and volatile, leading to grid instability, insufficient power during peak demand periods, and excessive power during off-peak periods. Unstable voltage can also damage power supply. Consequently, insufficient demand or insufficient grid capacity can lead to "wind and solar curtailment." Addressing these issues requires energy storage. This involves converting electrical energy into other forms of energy through physical or chemical means, storing them, and then converting them back into electricity when needed. Simply put, energy storage is like a large "power bank," storing electricity when photovoltaic or wind power is plentiful and releasing it when needed.

[0072] Taking electrochemical energy storage as an example, an embodiment of the present application provides an electrical device, which has a group of chemical batteries inside. The chemical elements in the chemical batteries are mainly used as energy storage media. The charging and discharging process is accompanied by chemical reactions or changes in the energy storage medium. Simply put, the electricity generated by wind and solar energy is stored in the chemical battery. When the use of external electricity reaches a peak, the stored electricity is released for use, or transferred to places where electricity is scarce for use.

[0073] Currently, energy storage has a wide range of application scenarios, including power 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:

[0074] 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, achieving load matching of electricity in time and space, enhancing the ability to absorb renewable energy, and are of great significance in grid system backup, alleviating peak load power supply pressure, and peak and frequency regulation.

[0075] Small and medium-sized energy storage cabinets used in industrial and commercial energy storage scenarios on the user side, as well as small household energy storage boxes used in home energy storage scenarios on the user side, primarily operate in a "peak shaving and valley filling" mode. Because electricity prices vary significantly between peak and valley times depending on electricity demand, users typically charge their energy storage cabinets / boxes during low-price periods after using their electrical equipment to reduce costs. During peak periods, the power in their electrical equipment is then discharged for use, saving on electricity costs. Furthermore, in remote areas and areas prone to natural disasters such as earthquakes and hurricanes, the presence of household electrical equipment provides users with a backup power source for themselves and the grid, eliminating the inconvenience caused by frequent power outages due to disasters or other reasons.

[0076] See also Figure 1 , Figure 1 4 is a schematic diagram of the structure of the energy storage system 400 provided in the embodiment of the present application. The embodiment of the present application takes the household energy storage scenario in the user-side energy storage as an example for explanation, and the electric device 300 of the present application is not limited to the household energy storage scenario.

[0077] An embodiment of the present application provides an energy storage system 400, which includes an electric energy conversion device 410, a first user load 420, a second user load 430, and an electrical device 300. The electrical device 300 is a small energy storage box that can be mounted on an outdoor wall. Specifically, photovoltaic panels can convert solar energy into electricity during periods of low electricity prices. The electrical device 300 is used to store this electricity and supply it to street lights and household appliances during peak electricity prices, or to provide power during power outages / blackouts.

[0078] Among them, the electric device 300 may include but is not limited to single cells, battery modules, battery packs, battery systems, etc. When the electric device 300 includes multiple batteries 200, the multiple batteries 200 are electrically connected and are all located inside the outer shell of the electric device 300. They can be protected by the outer shell and protected from interference from the external environment. Exemplarily, the multiple batteries 200 are arranged at intervals. The multiple batteries 200 can be connected in series, or in parallel, or a mixture of series and parallel connections to achieve greater capacity and power. The embodiments of the present application are described using the example of an electric device 300 including a battery 200, but it should be understood that the electric device 300 is not limited to this.

[0079] Optionally, battery 200 may be a secondary battery. A secondary battery refers to a battery cell that can be recharged to activate the active material after discharge and continue to be used. Battery 200 may be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-metal hydride battery, a nickel-cadmium battery, a lead-acid battery, or the like, and this application does not impose specific limitations thereon.

[0080] See also Figure 2 , Figure 2 It is a structural diagram of a battery 200 provided in an embodiment of the present application.

[0081] For ease of description, the length direction of the battery 200 is defined as the X direction, the width direction of the battery 200 is defined as the Y direction, and the height direction of the battery 200 is defined as the Z direction. The X direction, the Y direction, and the Z direction are perpendicular to each other.

[0082] The battery 200 may include a top cap assembly 100, a housing 210, and an electrode assembly 220. The top cap assembly 100 is connected to the housing 210 and forms a housing space with the housing 210. The electrode assembly 220 is located within the housing space. For example, the top cap assembly 100 may be welded to the housing 210. The housing 210 may be made of a metal material, such as an aluminum alloy. The battery 200 may be a cylindrical battery 200 or a square battery 200.

[0083] Among them, the electrode assembly 220 may include at least two battery cells (not shown). At least two battery cells are arranged in sequence along the thickness direction of the battery 200. The provision of multiple battery cells can increase the capacity of the battery 200, so that the battery 200 can be used for a long time, thereby increasing the applicable scenarios of the battery 200. Each battery cell may include a winding core, a first pole tab and a second pole tab. The first pole tab and the second pole tab are both connected to the winding core. The polarity of the first pole tab and the second pole tab are opposite, one is a positive pole tab and the other is a negative pole tab.

[0084] It should be noted that Figure 2 The purpose is only to schematically describe the connection relationship between the top cover assembly 100, the housing 210 and the electrode assembly 220, and it does not specifically limit the connection position, specific structure and quantity of each component. The structure shown in the embodiment of the present application does not constitute a specific limitation on the battery 200. In other embodiments of the present application, the battery 200 may include Figure 2 More or fewer components may be shown, some components may be combined, some components may be split, or different component arrangements may be used. The components shown in the figures may be implemented in hardware, software, or a combination of software and hardware.

[0085] Please refer to Figure 3 and Figure 4 , Figure 3 is a structural diagram of the top cover assembly 100 provided in an embodiment of the present application, Figure 4 yes Figure 3 The exploded structural diagram of the top cover assembly 100 is shown.

[0086] In this embodiment, the top cover assembly 100 may include a top cover 10, an upper plastic 20, a lower plastic 30, a pole 40, a connecting piece 51, a sealing ring 52, a pressure ring 53, a limiter 54, a support member 60, a heat insulation sheet 70 and an explosion-proof valve assembly 80.

[0087] Both the upper plastic 20 and the lower plastic 30 are mounted on the top cover 10. The upper plastic 20 is mounted on one side of the top cover 10 in the thickness direction (Z direction in the figure), and the lower plastic 30 is mounted on the other side of the top cover 10 in the thickness direction. The lower plastic 30 and the upper plastic 20 are respectively protruded from two opposing surfaces in the thickness direction of the top cover 10. The number of upper plastics 20 can be two. The two upper plastics 20 are installed on opposite sides of the top cover 10 in the length direction (X direction in the figure) with a spacing.

[0088] The pole 40 is mounted on the top cover 10, the upper plastic 20, and the lower plastic 30, and is insulated from the top cover 10 by the upper plastic 20, the lower plastic 30, and the sealing ring 52. The pole 40 can also serve as an electrode lead for the battery 200 to achieve electrical connection between the battery 200 and external devices. The number of poles 40 can be two. The two poles 40 can be a negative pole 40 and a positive pole 40, respectively. The two poles 40 can be spaced apart in the longitudinal direction of the top cover 10. Each pole 40 is mounted on the lower plastic 30, the top cover 10, an upper plastic 20, and a pressure ring 53.

[0089] The connecting tab 51 is located on the side of the lower plastic 30 facing away from the top cover 10 and is connected to the electrode post 40. It is also welded to the tab of the electrode assembly 220 to achieve electrical connection between the electrode post 40 and the electrode assembly 220. There can be two connecting tabs 51. The two connecting tabs 51 can be a positive electrode connecting tab 51 and a negative electrode connecting tab 51, respectively. The two connecting tabs 51 can be spaced apart in the length direction of the lower plastic 30 (the X direction in the figure). Each connecting tab 51 is connected to a single electrode post 40.

[0090] The sealing ring 52 is disposed on the outside of the electrode 40 and is located between the lower plastic 30 and the electrode 40, as well as between the top cover 10 and the electrode 40. The sealing ring 52 can be used to seal the gap between the top cover 10 and the electrode 40, preventing electrolyte from invading this gap and reducing the insulation between the top cover 10 and the electrode 40 and the safety of the electrode assembly 220. There can be two sealing rings 52. One sealing ring 52 is disposed on the positive electrode 40, and the other sealing ring 52 is disposed on the negative electrode 40.

[0091] The pressure ring 53 is mounted on the upper plastic 20 and is sleeved on the outside of the pole 40 and electrically connected to the pole 40. There can be two pressure rings 53. The two pressure rings 53 are respectively mounted on the two upper plastics 20 and are respectively electrically connected to the two poles 40.

[0092] The limiting body 54 is provided through the upper plastic 20 and is located between the pressure ring 53 and the top cover 10. The number of limiting bodies 54 can be multiple. Multiple limiting bodies 54 are provided at intervals through two upper plastics 20 and are located between the top cover 10 and the two pressure rings 53. For example, the number of limiting bodies 54 can be six. Three limiting bodies 54 are provided at intervals through one upper plastic 20 and are located between the top cover 10 and one pressure ring 53. Another three limiting bodies 54 are provided at intervals through another upper plastic 20 and are located between the top cover 10 and the other pressure ring 53.

[0093] The support member 60 is mounted on the lower plastic 30 and positioned between the lower plastic 30 and the top cover 10. The support member 60 abuts the lower plastic 30 and supports the top cover 10. In the event of thermal runaway, the support member 60 maintains a certain distance between the battery cell and the top cover 10, preventing the battery cell from floating toward the top cover 10. This prevents sparks from spraying out of the explosion-proof valve 81, reducing the risk of battery cell fire.

[0094] The heat shield 70 is located between the lower plastic 30 and the connecting piece 51 to provide good thermal insulation. There can be four heat shields 70 , two of which are located between the top cover 10 and one connecting piece 51 , and the other two between the top cover 10 and the other connecting piece 51 .

[0095] The explosion-proof valve assembly 80 is mounted on the top cover 10 and is used to protect the battery 200 from pressure relief.

[0096] The following will describe in detail the structure of each component in the top cover assembly 100 and the assembly relationship between the components with reference to the accompanying drawings.

[0097] Please refer to Figure 5 and Figure 6 , Figure 5 yes Figure 3 The schematic structural diagram of the top cover 10 of the top cover assembly 100 is shown at an angle. Figure 6 yes Figure 3 The top cover 10 of the top cover assembly 100 is shown as a schematic structural diagram from another angle.

[0098] The top cover 10 may include a third surface 101 and a fourth surface 102. The fourth surface 102 and the third surface 101 are disposed opposite each other in the thickness direction (Z direction in the figure) of the top cover 10. The third surface 101 may face away from the electrode assembly 220, and the fourth surface 102 may face toward the electrode assembly 220.

[0099] The top cover 10 may be provided with an explosion-proof hole 11. The explosion-proof hole 11 penetrates the top cover 10 along the thickness direction of the top cover 10. Exemplarily, the explosion-proof hole 11 may be located at the center of the top cover 10.

[0100] The top cover 10 may be provided with a mounting platform 12 and a recess 13. The mounting platform 12 may be provided on the third surface 101 and may protrude away from the top cover 10 relative to the third surface 101. The mounting platform 12 may also be provided around the outer edge of the explosion-proof hole 11. The opening of the recess 13 may be located on the fourth surface 102. The recess 13 may be recessed from the fourth surface 102 toward the interior of the top cover 10. The recess 13 may be coaxial with and in communication with the explosion-proof hole 11.

[0101] See also Figure 7 , Figure 7 It is along Figure 3 The cross-sectional diagram of a partial structure obtained by cutting along the cutting line AA is shown.

[0102] The explosion-proof valve assembly 80 may include an explosion-proof valve 81 and an explosion-proof valve protective sheet 82. The explosion-proof valve 81 and the explosion-proof valve protective sheet 82 may both be mounted on the top cover 10 and arranged sequentially in the thickness direction of the top cover 10. Specifically, the explosion-proof valve 81 may be located in the groove 13 of the top cover 10 and cover the opening of the explosion-proof hole 11 located on the fourth surface 102 of the top cover 10. The explosion-proof valve protective sheet 82 may be connected to the mounting platform 12 of the top cover 10 and cover the opening of the explosion-proof hole 11 located on the first surface 311 of the top cover 10. The explosion-proof valve protective sheet 82 may also cover the explosion-proof valve 81.

[0103] Please refer to Figure 8 and Figure 9 , Figure 8 yes Figure 3 The schematic structural diagram of the lower plastic 30 of the top cover assembly 100 is shown at an angle. Figure 9 yes Figure 3 The schematic diagram of the structure of the lower plastic 30 of the top cover assembly 100 is shown in FIG. Figure 9 In the figure, the dotted arrows indicate the exhaust path.

[0104] The lower plastic 30 can be stacked with the top cover 10. The lower plastic 30 can include a lower plastic body 31 and a central boss 32. The lower plastic body 31 is located on one side of the top cover 10 in the thickness direction and is fixedly connected to the top cover 10 to achieve a fixed connection between the lower plastic 30 and the top cover 10. The central boss 32 can be fixedly connected to the lower plastic body 31 and protrude relative to the second surface 312 of the lower plastic body 31. The central boss 32 can be used to abut the electrode assembly 220.

[0105] Specifically, the lower plastic body 31 may include a first surface 311 and a second surface 312. The second surface 312 may be disposed opposite the first surface 311 in the thickness direction (Z direction in the figure) of the lower plastic body 30. The first surface 311 may face the fourth surface 102 of the top cover 10, and the second surface 312 may face the electrode assembly 220.

[0106] The lower plastic member 30 may be provided with a cavity 33. The cavity 33 may be located between the lower plastic body 31 and the central boss 32. The opening of the cavity 33 may be located on the first surface 311 of the lower plastic body 31. The cavity 33 may be recessed from the first surface 311 of the lower plastic body 31 into the interior of the lower plastic body 31 and the central boss 32. In the thickness direction of the lower plastic member 30, the cavity 33 may extend from the lower plastic body 31 to the central boss 32. In the width direction of the lower plastic member 30, the cavity 33 may extend from one side of the lower plastic member 30 to the other side of the lower plastic member 30.

[0107] The central boss 32 can be positioned opposite the explosion-proof hole 11 of the top cover 10 in the Z direction. In the Z direction, the projection of the central boss on the top cover 10 can partially overlap with the explosion-proof hole 11 of the top cover 10. That is, a portion of the central boss 32 can be covered by the projection of the explosion-proof hole 11 of the top cover 10 on the lower plastic body 30 in the Z direction. The central boss 32 can include a bottom surface 321, a first side surface 322, and a second side surface 323. The bottom surface 321 can be spaced apart from the second surface 312 of the lower plastic body 31 in the thickness direction of the lower plastic body 30. The first side surface 322 and the second side surface 323 can both be connected between the bottom surface 321 and the second surface 312 of the lower plastic body 31. The first side surface 322 and the second side surface 323 can be positioned opposite and spaced apart in the length direction (X direction in the figure) of the lower plastic body 30.

[0108] The central boss 32 may be provided with a plurality of first vent holes 324 and a plurality of second vent holes 325. The plurality of first vent holes 324 may be spaced apart along the width direction (Y direction in the figure) of the lower plastic 30. The structures of the plurality of first vent holes 324 may be similar, identical, or different. Each first vent hole 324 is located on the first side surface 322 and the bottom surface 321, and penetrates the central boss 32 along the length direction and the thickness direction (Z direction in the figure) of the lower plastic 30. Each first vent hole 324 may be connected to the cavity 33. In other words, each first vent hole 324 is a through hole. A portion of each first vent hole 324 is located on the first side surface 322, and another portion of each first vent hole 324 is located on the bottom surface 321. The plurality of second vent holes 325 may be spaced apart along the width direction of the lower plastic 30. The structures of the plurality of second vent holes 325 may be similar, identical, or different. Each second vent hole 325 is located on the second side surface 323 and the bottom surface 321, and extends through the central boss 32 along the length and thickness of the lower plastic 30. Each second vent hole 325 can communicate with the cavity 33. In other words, each second vent hole 325 is a through hole. A portion of each second vent hole 325 is located on the second side surface 323, while another portion of each first vent hole 324 is located on the bottom surface 321.

[0109] For example, the number of the first exhaust holes 324 may be five, and the five first exhaust holes 324 are spaced apart in the width direction of the lower plastic 30 . The number of the second exhaust holes 325 may be five, and the five second exhaust holes 325 are spaced apart in the width direction of the lower plastic 30 .

[0110] It can be understood that by providing multiple first exhaust holes 324 and multiple second exhaust holes 325 on the side of the central boss 32, the number of exhaust channels on the lower plastic 30 can be increased, and the exhaust rate of the gas inside the battery cell when the battery cell thermal runaway is increased, thereby improving the safety performance of the top cover assembly 100.

[0111] The central boss 32 may be provided with a plurality of third vent holes 326. The structures of the plurality of third vent holes 326 may be similar, identical, or different. The plurality of third vent holes 326 are spaced apart on the bottom surface 321 along the width direction of the lower plastic 30. Each third vent hole 326 penetrates the central boss 32 along the thickness direction of the lower plastic 30 and communicates with the cavity 33. In other words, each third vent hole 326 is a through hole. Exemplarily, the number of third vent holes 326 may be nine. The nine third vent holes 326 may be spaced apart along the thickness direction of the lower plastic 30. The nine third vent holes 326 may include three circular holes, two rectangular holes, two relatively small elliptical holes, and two relatively large elliptical holes.

[0112] It can be understood that by providing a plurality of third exhaust holes 326 on the bottom surface 321 of the central boss 32, the number of exhaust channels on the lower plastic 30 can be increased as much as possible while ensuring the strength of the central boss 32, so that the gas inside the battery cell can have more gas passages, disperse the stress applied to the lower plastic 30 when the battery cell thermal runaway occurs, avoid the problem of failure of the top cover assembly 100 due to stress concentration, and have stronger reliability.

[0113] Please continue reading Figure 8 and Figure 9 The lower plastic 30 may further include a partition 34. The two ends of the partition 34 are respectively connected to the two opposite side walls of the cavity 33 along the length direction of the lower plastic 30. The partition 34 is also connected to the bottom wall of the cavity 33. A snap 341 may be provided at one end of the partition 34 away from the bottom wall of the cavity 33. The partition 34 may cooperate with the inner wall of the cavity 33 to separate a mounting groove 35 in the cavity 33. The mounting groove 35 may be located between the lower plastic body 31 and the central boss 32. The opening of the mounting groove 35 may be located on the first surface 311 of the lower plastic body 31. The mounting groove 35 may be connected to at least one of the plurality of first exhaust holes 324, at least one of the plurality of third exhaust holes 326, and at least one of the plurality of second exhaust holes 325.

[0114] The number of partitions 34 can be multiple. The structures of the multiple partitions 34 can be the same or different. The multiple partitions 34 can cooperate with the inner wall of the cavity 33 to separate a plurality of mounting slots 35 within the cavity 33. For example, the number of partitions 34 can be two. The two partitions 34 can be located on either side of the lower plastic 30 in the width direction and spaced apart. The two partitions 34 can cooperate with the inner wall of the cavity 33 to separate two mounting slots 35 within the cavity 33. The two mounting slots 35 can be spaced apart in the width direction of the lower plastic 30.

[0115] Please refer to Figure 8 、 Figure 10a and Figure 10b , Figure 10a yes Figure 8 The schematic diagram of the partial structure of the lower plastic 30 at an angle is shown. Figure 10b It is along Figure 8 The cross-sectional view of a portion of the structure of the lower plastic 30 obtained by cutting along the cutting line BB is shown.

[0116] The mounting groove 35 may include a first sidewall 351, a second sidewall 352, a third sidewall 353, and a fourth sidewall 354. The first sidewall 351 and the second sidewall 352 may be spaced apart and opposed to each other along the lengthwise direction (X-direction in the figure) of the lower plastic 30. That is, the first sidewall 351 and the second sidewall 352 are the two opposing sidewalls of the mounting groove 35 along the lengthwise direction of the lower plastic 30. The third sidewall 353 and the fourth sidewall 354 are both connected between the first sidewall 351 and the second sidewall 352. The fourth sidewall 354 and the third sidewall 353 are spaced apart and opposed to each other along the widthwise direction (Y-direction in the figure) of the lower plastic 30. That is, the third sidewall 353 and the fourth sidewall 354 are the two opposing sidewalls of the mounting groove 35 along the lengthwise direction of the lower plastic 30.

[0117] The first sidewall 351 is disposed adjacent to the first side surface 322, and the second sidewall 352 is disposed adjacent to the second side surface 323. The first sidewall 351 and the second sidewall 352 can both be inclined surfaces arranged at an angle relative to the bottom wall of the mounting groove 35. The first sidewall 351 and the second sidewall 352 can extend in mutually intersecting directions. The distance between the first sidewall 351 and the second sidewall 352 along the length of the lower plastic body 30 can gradually decrease from the first surface 311 to the second surface 312 of the lower plastic body 31.

[0118] Please refer to Figure 9 and Figure 11 , Figure 11 yes Figure 3 The structure diagram of the lower plastic 30 of the top cover assembly 100 is shown at another angle.

[0119] The lower plastic 30 may be provided with a first hole group 36 and a second hole group 37. Along the length direction of the lower plastic 30, the first hole group 36 and the second hole group 37 are respectively located on either side of the central boss 32 and are both disposed adjacent to the central boss 32. The first hole group 36 and the second hole group 37 may be symmetrically disposed.

[0120] The first hole group 36 may include a sixth vent hole 361 and a plurality of seventh vent holes 362. The sixth vent hole 361 and the plurality of seventh vent holes 362 may both penetrate the lower plastic 30 along the thickness direction of the lower plastic 30. The sixth vent hole 361 may be located at the center of the first hole group 36. The structures of the plurality of seventh vent holes 362 may be similar, identical, or different. The plurality of seventh vent holes 362 may be arranged in at least two first annular rings T1, spaced apart from each other, along a direction outward from a centerline O1 of the sixth vent hole 361 in the width direction of the lower plastic 30. In the at least two first annular rings T1, the plurality of seventh vent holes 362 located in the same first annular ring T1 are spaced apart, and the plurality of seventh vent holes 362 located in different first annular rings T1 are also spaced apart. In the Z direction, the projection of the explosion-proof hole 11 of the top cover 10 on the lower plastic body 31 at least partially covers the projection of the central boss 32 on the lower plastic body 31 and the projection of the plurality of seventh exhaust holes on the lower plastic body 31. In other words, the projection of the explosion-proof hole 11 of the top cover 10 on the lower plastic body 30 along the Z direction at least partially covers the central boss 32 and the plurality of seventh exhaust holes 362.

[0121] For example, the sixth exhaust hole 361 may be circular. The seventh exhaust hole 362 may be elliptical. There may be one sixth exhaust hole 361. There may be eighteen seventh exhaust holes 362. The eighteen seventh exhaust holes 362 may be arranged in two first annular rings T1, spaced apart from one another, along the widthwise centerline of the sixth exhaust hole 361 and extending outward from the centerline of the lower plastic 30. The inner first annular ring T1 may have six seventh exhaust holes 362, while the outer first annular ring T1 may have twelve seventh exhaust holes 362.

[0122] It is understood that by ensuring that the projection of the explosion-proof hole 11 on the lower plastic 30 along the Z direction covers at least a portion of the central boss 32 and the plurality of seventh exhaust holes 362, the first hole group 36 can be configured as an exhaust structure disposed around the explosion-proof hole 11. This arrangement allows the first hole group 36 to be disposed opposite the explosion-proof hole 11 in the Z direction. This allows the internal gas of the battery cell to be discharged directly from the explosion-proof valve 81 through the first hole group 36 when thermal runaway occurs in the battery cell. This shortens the exhaust path of the internal gas of the battery cell and avoids the problem of the internal gas of the battery cell being unable to be effectively exhausted through the explosion-proof valve 81 due to the blockage of the exhaust passage in the top cover 10, which could lead to excessive internal gas pressure and explosion of the battery cell. This effectively improves the safety performance of the top cover assembly 100.

[0123] By arranging the sixth exhaust hole 361 at the center of the first hole group 36 and arranging the plurality of seventh exhaust holes 362 outside the sixth exhaust hole 361 and nesting them in at least two first annular rings T1, the exhaust hole diameter of the lower plastic 30 around the explosion-proof valve 81 can be reduced while ensuring that the total exhaust channel volume in the lower plastic 30 is not reduced, thereby preventing the tabs of the battery cell from contacting the top cover 10 through the exhaust holes and causing a short circuit. The exhaust holes in the first hole group 36 are arranged in a more compact structure, the arrangement density of the exhaust holes in the first hole group 36 is increased, and the exhaust reliability of the lower plastic 30 is improved.

[0124] Please continue reading Figure 9 and Figure 11 The dimension D1 of each first annular ring T1 along the width direction of the lower plastic 30 is greater than the dimension D2 of each first annular ring T1 along the length direction of the lower plastic 30. Furthermore, the dimension D2 of each first annular ring T1 along the length direction of the lower plastic 30 gradually increases and then gradually decreases from one side of the width direction of the lower plastic 30 to the other side of the width direction of the lower plastic 30. For example, the shape of the first annular ring T1 can be triangular.

[0125] It will be appreciated that by making the dimension D1 of each first annular ring T1 along the width direction of the lower plastic 30 greater than the dimension D2 of each first annular ring T1 along the length direction of the lower plastic 30, a greater number of seventh exhaust holes 362 within the same first annular ring T1 can be arranged near the explosion-proof hole 11 of the top cover 10, thereby effectively shortening the gas flow path and allowing gas to pass through more quickly and conveniently. Furthermore, by making the dimension D2 of each first annular ring T1 along the length direction of the lower plastic 30 gradually increase and then decrease from one side of the width direction of the lower plastic 30 to the other side of the width direction of the lower plastic 30, each first annular ring T1 can be arranged in a triangular shape, facilitating a small-diameter, high-density arrangement of the exhaust holes.

[0126] The second hole group 37 may include an eighth vent hole 371 and a plurality of ninth vent holes 372. The eighth vent hole 371 and the plurality of ninth vent holes 372 may both penetrate the lower plastic 30 along the thickness direction of the lower plastic 30. The eighth vent hole 371 may be located at the center of the second hole group 37. The structures of the plurality of ninth vent holes 372 may be similar, identical, or different. The plurality of ninth vent holes 372 may be arranged in at least two second annular rings T2, spaced outward from the centerline O2 of the eighth vent hole 371 in the width direction of the lower plastic 30, and sequentially spaced outside the eighth vent hole 371. Within the at least two second annular rings T2, the plurality of ninth vent holes 372 located in the same second annular ring T2 are spaced apart, and the plurality of ninth vent holes 372 located in different second annular rings T2 are also spaced apart. In the Z direction, the projection of the explosion-proof hole 11 of the top cover 10 on the lower plastic body 31 at least partially covers the projection of the central boss 32 on the lower plastic body 31 and the projection of the plurality of ninth exhaust holes 372 on the lower plastic body 31. In other words, the projection of the explosion-proof hole 11 of the top cover 10 on the lower plastic body 30 along the Z direction at least partially covers the central boss 32 and the plurality of ninth exhaust holes 372.

[0127] For example, the eighth exhaust hole 371 may be circular. The ninth exhaust hole 372 may be elliptical. There may be one eighth exhaust hole 371. There may be eighteen ninth exhaust holes 372. The eighteen ninth exhaust holes 372 may be arranged in two second annular rings T2, spaced apart from one another, along the widthwise centerline of the eighth exhaust hole 371 and extending outward from the centerline of the lower plastic 30. The inner second annular ring T2 may have six ninth exhaust holes 372, while the outer second annular ring T2 may have twelve ninth exhaust holes 372.

[0128] It is understood that by ensuring that the projection of the explosion-proof hole 11 on the lower plastic 30 along the Z direction covers at least a portion of the central boss 32 and the plurality of ninth exhaust holes 372, the second hole group 37 can be configured as an exhaust structure disposed around the explosion-proof hole 11. This arrangement allows the second hole group 37 to be disposed opposite the explosion-proof hole 11 in the Z direction. This allows the internal gas of the battery cell to be discharged directly from the explosion-proof valve 81 through the second hole group 37 when thermal runaway occurs in the battery cell. This shortens the exhaust path of the internal gas of the battery cell and avoids the problem of the internal gas of the battery cell being unable to be effectively exhausted through the explosion-proof valve 81 due to the blockage of the exhaust passage in the top cover 10, which could cause the internal gas of the battery cell to explode due to excessive internal gas pressure. This effectively improves the safety performance of the top cover assembly 100.

[0129] By arranging the eighth exhaust hole 371 at the center of the second hole group 37 and arranging the plurality of ninth exhaust holes 372 on the outside of the eighth exhaust hole 371 and nesting them in the form of at least two second annular rings T2, the exhaust hole diameter of the lower plastic 30 around the explosion-proof valve 81 can be reduced while ensuring that the total exhaust channel volume in the lower plastic 30 is not reduced, thereby preventing the tabs of the battery cell from contacting the top cover 10 through the exhaust holes and causing a short circuit. The exhaust holes in the second hole group 37 are arranged in a more compact structure, the arrangement density of the exhaust holes in the second hole group 37 is increased, and the exhaust reliability of the lower plastic 30 is improved.

[0130] Please continue reading Figure 9 and Figure 11 The dimension D3 of each second annular ring T2 along the width direction of the lower plastic 30 is greater than the dimension D4 of each second annular ring T2 along the length direction of the lower plastic 30. Furthermore, the dimension D4 of each second annular ring T2 along the length direction of the lower plastic 30 gradually increases and then gradually decreases from one side of the width direction of the lower plastic 30 to the other side of the width direction of the lower plastic 30. For example, the shape of the second annular ring T2 can be triangular.

[0131] It will be appreciated that by ensuring that the dimension D3 of each second annular ring T2 along the width direction of the lower plastic 30 is greater than the dimension D4 of each second annular ring T2 along the length direction of the lower plastic 30, a greater number of ninth exhaust holes 372 within the same second annular ring T2 can be arranged near the explosion-proof hole 11 of the top cover 10, thereby effectively shortening the gas flow path and allowing gas to pass through more quickly and conveniently. Furthermore, by ensuring that the dimension D4 of each second annular ring T2 along the length direction of the lower plastic 30 gradually increases and then decreases from one side of the width direction of the lower plastic 30 to the other side of the width direction of the lower plastic 30, each second annular ring T2 can be arranged in a triangular shape, facilitating a small-diameter, high-density arrangement of the exhaust holes.

[0132] Please refer to Figure 8 and Figure 9 The lower plastic member 30 may further include a protrusion 301. The protrusion 301 may be located on both sides of the central boss 32 in the width direction (X direction in the figure), connected to both the lower plastic body 31 and the central boss 32, and protruding relative to the second surface 312 of the lower plastic body 31. The protrusion 301 may protrude from the second surface 312 of the lower plastic body 31 at a height less than the protrusion of the central boss 32 relative to the second surface 312 of the lower plastic body 31. The sixth vent 361, the plurality of seventh vents 362, the eighth vent 371, and the plurality of ninth vents 372 are all provided on the protrusion 301 and extend through the protrusion 301 along the thickness direction of the lower plastic member 30.

[0133] The lower plastic 30 may also be provided with an air relief groove 302. The air relief groove 302 may be located between the lower plastic body 31 and the protrusion 301. The opening of the air relief groove 302 is located on the first surface 311. The air relief groove 302 may be recessed from the first surface 311 of the lower plastic body 31 toward the protrusion 301 and the central boss 32. The air relief groove 302 is also connected to the cavity 33, the mounting slot 35, the sixth exhaust hole 361, the plurality of seventh exhaust holes 362, the eighth exhaust hole 371, and the plurality of ninth exhaust holes 372. In the thickness direction of the top cover assembly 100, the projection of the air relief groove 302 on the top cover 10 may cover the explosion-proof hole 11. That is, the projection of the air relief groove 302 on the top cover 10 along the Z direction may cover the explosion-proof hole 11 of the top cover 10.

[0134] It can be understood that by providing a concave air discharge groove 302 on the first surface 311 of the lower plastic 30, the space enclosed by the air discharge groove 302 can be utilized to leave a certain gap between the lower plastic 30 and the top cover 10, so that the explosion-proof valve 81 installed in the explosion-proof hole 11 of the top cover 10 can increase the airflow discharge around the explosion-proof hole 11 when exhausting the battery cell, thereby improving the exhaust effect of the explosion-proof valve 81 and ensuring the safety of the battery 200.

[0135] The lower plastic body 30 may further include a first edge boss 38 and a second edge boss 39. Both the first edge boss 38 and the second edge boss 39 are connected to the lower plastic body 31 and are disposed so as to protrude relative to the second surface 312 of the lower plastic body 31. The first edge boss 38 is located at one end of the lengthwise direction of the lower plastic body 31, and the second edge boss 39 is located at the other end of the lengthwise direction of the lower plastic body 31. Both the first edge boss 38 and the second edge boss 39 may be configured to abut against the electrode assembly 220.

[0136] The first edge boss 38 is provided with a plurality of fourth vent holes 381. The structures of the plurality of fourth vent holes 381 can be similar, identical, or different. The plurality of fourth vent holes 381 are spaced apart along the width of the lower plastic 30 and are arranged opposite the plurality of first vent holes 324 along the length of the lower plastic 30. Each fourth vent hole 381 extends through the first edge boss 38 along the length of the lower plastic 30. For example, there can be four fourth vent holes 381.

[0137] The second edge boss 39 is provided with a plurality of fifth vent holes 391. The structures of the plurality of fifth vent holes 391 may be similar, identical, or different. The plurality of fifth vent holes 391 are spaced apart along the width of the lower plastic 30 and are arranged opposite the plurality of second vent holes 325 along the length of the lower plastic 30. Each fifth vent hole 391 extends through the second edge boss 39 along the length of the lower plastic 30. For example, there may be four fifth vent holes 391.

[0138] It is understood that by providing multiple fourth exhaust holes 381 on the side of the first edge boss 38 and multiple fifth exhaust holes 391 on the side of the second edge boss 39, an exhaust path can be formed from both sides of the length direction of the lower plastic 30 to the central area of the lower plastic 30. Gas on both sides of the length direction of the lower plastic 30 passes through the first edge boss 38 and the second edge boss 39 respectively and converges toward the central boss 32. Then, it can be discharged to the outside of the battery 200 through the explosion-proof valve 81 installed in the explosion-proof hole 11 of the top cover 10. This effectively increases the number of exhaust channels on the lower plastic 30, improves the exhaust rate of gas inside the battery cell when the battery cell experiences thermal runaway, and thus improves the safety performance of the top cover assembly 100.

[0139] Please refer to Figure 12 , Figure 12 It is along Figure 3 The diagram shows a cross-sectional view of a portion of the top cover assembly 100, taken along section line CC. The support member 60 can be located within the mounting groove 35 of the lower plastic 30. In the thickness direction of the top cover assembly 100, one side of the support member 60 abuts the bottom wall of the mounting groove 35, while the other side of the support member 60 supports the top cover 10. The support member 60 can be made of an insulating material that is resistant to electrolyte corrosion. For example, the support member 60 can be located entirely within the mounting groove 35. The other side of the support member 60 can abut against the top cover 10 in the event of thermal runaway of the battery cell, while maintaining a gap between the support member 60 and the opening of the mounting groove in normal operation. In the thickness direction of the lower plastic 30, the gap between the support member 60 and the opening of the mounting groove can be within a range of 0.1 mm to 0.2 mm (inclusive). The material of the support member 60 can be ceramic.

[0140] It is understandable that when a battery cell experiences thermal runaway, the explosion-proof valve 81 installed on the top cover 10 is easily broken, and the combustible gases and sparks generated by the battery cell are released through the explosion-proof valve 81 into the air outside the battery 200. There, they react with the oxygen in the air, causing the battery cell to ignite. Due to the high temperature of the battery cell during thermal runaway, the lower plastic 30 is easily melted by the high temperature, making it difficult for the lower plastic 30 to act as a stop when the battery cell floats under the action of the electrolyte and air pressure. This causes the distance between the battery cell and the top cover 10 to become closer, or even to contact, and increases the amount of combustible gases and sparks that splash out of the battery 200. This further increases the possibility of the combustible gases and sparks coming into contact with oxygen in the air, exacerbating the risk of battery cell fire.

[0141] Therefore, in the implementation of this application, by providing an insulating and electrolyte-corrosion-resistant support member 60 between the lower plastic 30 and the top cover 10, the top cover 10 can be effectively supported, improving the situation in which the lower plastic 30 deforms at high temperatures in the early stages of thermal runaway of the battery cell and loses its restraining effect on the battery cell. In addition, even if the battery cell thermal runaway causes the lower plastic 30 to melt, the support member 60 can still support the top cover 10 and the battery cell, preventing the battery cell from floating close to the top cover 10, thereby suppressing the phenomenon of electric sparks splashing out of the explosion-proof valve 81 and reducing the risk of battery cell fire.

[0142] In the embodiment of the present application, the support member 60 can be fixed by the buckle 341 of the partition 34. It is understandable that by engaging the support member 60 with the buckle 341 of the partition 34, the support member 60 can be quickly and easily fixedly connected to the lower plastic 30, thereby effectively limiting the movement of the support member 60, reducing the risk of the support member 60 falling off the lower plastic 30, and improving the retention stability and reliability of the support member 60.

[0143] The number of support members 60 can be one or more. When there are multiple support members 60, the structures of the multiple support members 60 can be similar, identical, or different. The multiple support members 60 are spaced apart and distributed between the top cover 10 and the lower plastic 30. Each support member 60 is supported between the top cover 10 and the lower plastic 30.

[0144] Exemplarily, the number of support members 60 can be two. In the Y direction, the two support members 60 can be located on both sides of the explosion-proof hole 11 of the top cover 10. It can be understood that compared to setting one support member 60 between the lower plastic 30 and the top cover 10, setting two support members 60 between the lower plastic 30 and the top cover 10, and making the two support members 60 located on both sides of the explosion-proof hole 11 of the top cover 10, can more securely maintain a certain distance between the lower plastic 30 and the top cover 10. In addition, when the battery cell thermal runaway occurs, the two support members 60 have a stronger supporting effect on the battery cell, which can more effectively suppress the ignition spark generated by the battery cell from passing through the explosion-proof valve 81 to reach the outside of the battery 200 and causing the battery cell to catch fire.

[0145] The following description of the support member 60 will be made in detail by taking the structure of one support member 60 as an example. In the absence of any conflict, the description of the structure of one support member 60 can be applied to other support members 60 .

[0146] In the embodiments of this application, Figure 12As shown, in the Z direction, the projection of the support member 60 on the top cover 10 covers a portion of the explosion-proof hole 11. That is, the projection of the support member 60 on the top cover 10 along the Z direction can cover a portion of the explosion-proof hole 11 of the top cover 10. Alternatively, in the Z direction, the projection of the support member 60 on the top cover 10 is spaced apart from the explosion-proof hole 11. That is, the projection of the support member 60 on the top cover 10 along the Z direction can be spaced apart from the explosion-proof hole 11 of the top cover 10.

[0147] It can be understood that by arranging the support member 60 close to the explosion-proof hole 11 of the top cover 10, it can be ensured that there is always an appropriate gap between the top cover 10 and the lower plastic 30 at the periphery of the explosion-proof hole 11. Therefore, when the battery cell thermally runs away, the support member 60 can exert its supporting force at a closer distance to support the battery cell and prevent the battery cell from approaching the top cover 10, thereby improving reliability.

[0148] See also Figure 13 , Figure 13 It is along Figure 3 The section line EE shown is a schematic cross-sectional view of a portion of the structure of the top cover assembly 100 .

[0149] A first air passage S1 is formed between the support member 60 and the first sidewall 351 of the mounting groove 35. The first air passage S1 may be a gap between the support member 60 and the first sidewall 351 of the mounting groove 35. The first air passage S1 communicates with at least one of the plurality of first exhaust holes 324.

[0150] It is understood that a first air channel S1 is formed between the support member 60 and the first sidewall 351 of the mounting groove 35, and the first air channel S1 is connected to at least one of the plurality of first exhaust holes 324. The first air channel S1 provides a passage for gas entering the mounting groove 35 through the first exhaust hole 324, thereby preventing the support member 60 from blocking the first exhaust hole 324 of the central boss 32, which could cause poor exhaust and increased air pressure, leading to battery cell explosion. This effectively exhausts gas from within the battery cell, improving the reliability of gas exhaust.

[0151] like Figure 13 As shown, the dimension H1 of the first air passage S1 in the longitudinal direction (the X direction in the figure) of the lower plastic member 30 gradually decreases from the opening of the mounting groove 35 toward the bottom wall of the mounting groove 35. In other words, the distance (H1 in the figure) between the support member 60 and the first sidewall 351 of the mounting groove 35 can gradually decrease from the opening of the mounting groove 35 toward the bottom wall of the mounting groove 35.

[0152] It is understood that by designing the first sidewall 351 of the mounting groove 35 as an inclined surface inclined relative to the bottom wall of the mounting groove 35, and by gradually decreasing the distance between the support member 60 and the first sidewall 351 of the mounting groove 35 (i.e., the dimension H1 of the first air passage S1 in the longitudinal direction of the lower plastic), the distance between the support member 60 and the first sidewall 351 can be narrower at the bottom and wider at the top. The narrower bottom design reduces the shaking of the support member 60 after it is installed in the lower plastic 30, while the wider top design ensures that there is a channel for exhaust in the area where the support member 60 is located, thereby improving the reliability of exhaust from the lower plastic 30.

[0153] Please continue reading Figure 13 A second air passage S2 is formed between the support member 60 and the second sidewall 352 of the mounting groove 35. The second air passage S2 may be a gap between the support member 60 and the second sidewall 352 of the mounting groove 35. The second air passage S2 communicates with at least one of the plurality of second exhaust holes 325.

[0154] It is understood that a second air channel S2 is formed between the support member 60 and the second sidewall 352 of the mounting groove 35, and the second air channel S2 is connected to at least one of the plurality of second exhaust holes 325. The second air channel S2 provides a passage for gas entering the mounting groove 35 through the second exhaust hole 325, thereby preventing the support member 60 from blocking the second exhaust hole 325 of the central boss 32, thereby preventing poor exhaust and increased air pressure, which could lead to battery cell explosion. This effectively exhausts gas from within the battery cell, improving the reliability of gas exhaust.

[0155] like Figure 13 As shown, the dimension H2 of the second air passage S2 in the longitudinal direction (the X direction in the figure) of the lower plastic member 30 gradually decreases from the opening of the mounting groove 35 toward the bottom wall of the mounting groove 35. In other words, the distance (H2 in the figure) between the support member 60 and the second sidewall 352 of the mounting groove 35 can gradually decrease from the opening of the mounting groove 35 toward the bottom wall of the mounting groove 35.

[0156] It is understood that by designing the second sidewall 352 of the mounting groove 35 as an inclined surface inclined relative to the bottom wall of the mounting groove 35, and by gradually decreasing the distance between the support member 60 and the second sidewall 352 of the mounting groove 35 (i.e., the dimension H2 of the second air passage S2 in the longitudinal direction of the lower plastic), the distance between the support member 60 and the second sidewall 352 can be narrower at the bottom and wider at the top. The narrower bottom design reduces the shaking of the support member 60 after it is installed in the lower plastic 30, while the wider top design ensures that there is a channel for exhaust in the area where the support member 60 is located, thereby improving the reliability of exhaust from the lower plastic 30.

[0157] See also Figure 14 , Figure 14 yes Figure 3 A structural schematic diagram of a partial structure of the top cover assembly 100 is shown.

[0158] In an embodiment of the present application, a third air channel S3 may be formed between the support member 60 and the third side wall 353 of the mounting groove 35. The third air channel S3 may be in communication with both the first air channel S1 and the second air channel S2. And / or, a fourth air channel S4 may be formed between the support member 60 and the fourth side wall 354 of the mounting groove 35. The fourth air channel S4 is in communication with both the first air channel S1 and the second air channel S2. Of course, in some other embodiments, the support member 60 may also abut against the third side wall 353 and / or the fourth side wall 354 of the mounting groove 35, and this is not strictly limited.

[0159] It is understood that by forming the third air channel S3 and / or the fourth air channel S4 between the support member 60 and the sidewall of the mounting groove 35, it is possible to further prevent the problem of poor exhaust and increased air pressure, which could lead to battery cell explosion, caused by the support member 60 blocking the first exhaust hole 324 and / or the second exhaust hole 325 of the central boss 32. Furthermore, each additional air channel between the support member 60 and the sidewall of the mounting groove 35 provides a new channel for gas circulation within the mounting groove 35, thereby effectively improving the exhaust efficiency and reliability of the gas.

[0160] Please refer to Figure 13 、 Figure 14 and Figure 15 , Figure 15 yes Figure 3 The structure diagram of the support member 60 of the top cover assembly 100 is shown at an angle.

[0161] The support member 60 includes a main body 61, a first fixing portion 62, and a second fixing portion 63. The main body 61 may include a first supporting surface 611, a second supporting surface 612, a first connecting surface 613, a second connecting surface 614, a first transition surface 615, and a second transition surface 616. The first supporting surface 611 and the second supporting surface 612 may be spaced apart and opposite each other in the thickness direction (Z direction in the figure) of the support member 60. The first supporting surface 611 may contact the bottom wall of the mounting groove 35, while the second supporting surface 612 may support the top cover 10. The first connecting surface 613 and the second connecting surface 614 are both connected between the first supporting surface 611 and the second supporting surface 612. The second connecting surface 614 may be spaced apart and opposite to the first connecting surface 613 in the width direction (Y direction in the figure) of the lower plastic member 30. The first transition surface 615 and the second transition surface 616 are both connected between the first supporting surface 611 and the second supporting surface 612, and between the first connecting surface 613 and the second connecting surface 614. The first transition surface 615 and the second transition surface 616 may be disposed opposite to each other and spaced apart in the length direction (Y direction in the figure) of the lower plastic 30 .

[0162] The first connecting surface 613 may include a first sub-surface 6131 and two second sub-surfaces 6132. The first sub-surface 6131 is connected between the two second sub-surfaces 6132. In the thickness direction of the lower plastic 30 (Z direction in the figure), the second sub-surface 6132, the first sub-surface 6131, and the second sub-surface 6132 are arranged in sequence. That is, the two second sub-surfaces 6132 are respectively connected to opposite sides of the first sub-surface 6131 along the thickness direction of the lower plastic 30. The first sub-surface 6131 may be arranged parallel to the thickness direction of the lower plastic 30. Both second sub-surfaces 6132 may be arranged obliquely with respect to the thickness direction of the lower plastic 30, and their extension directions may intersect.

[0163] The second connecting surface 614 may include a third sub-surface 6141 and two fourth sub-surfaces 6142. The third sub-surface 6141 is connected between the two fourth sub-surfaces 6142. In the thickness direction of the lower plastic 30 (Z direction in the figure), the fourth sub-surface 6142, the third sub-surface 6141, and the other fourth sub-surface 6142 are arranged in sequence. That is, the two fourth sub-surfaces 6142 are respectively connected to opposite sides of the third sub-surface 6141 along the thickness direction of the lower plastic 30. The third sub-surface 6141 may be arranged parallel to the thickness direction of the lower plastic 30. Both fourth sub-surfaces 6142 may be arranged obliquely with respect to the thickness direction of the lower plastic 30, and their extension directions may intersect.

[0164] The first fixing portion 62 is connected to a first sub-surface 6131. The first fixing portion 62 and the two second sub-surfaces 6132 on the same side are respectively arranged to form two first avoidance grooves 64. The second fixing portion 63 is connected to a third sub-surface 6141. The second fixing portion 63 and the two fourth sub-surfaces 6142 on the same side are respectively arranged to form second avoidance grooves 65. In the two first avoidance grooves 64, each first avoidance groove 64 is connected to any one or more combinations of the first air duct S1, the second air duct S2, the third air duct S3, and the fourth air duct S4. In the two second avoidance grooves 65, each second avoidance groove 65 is connected to any one or more combinations of the first air duct S1, the second air duct S2, the third air duct S3, and the fourth air duct S4. Among the two first avoidance grooves 64, a first avoidance groove 64 close to the top cover 10 can accommodate at least part of the buckle 341 of the partition 34. Further, as Figure 12 As shown, the surface of the buckle 341 facing the main body 61 can be a guiding slope 342. The guiding slope 342 can be set obliquely with respect to the thickness direction of the lower plastic 30. The guiding slope 342 can improve the installation performance of the support member 60 and prevent the support member 60 from scratching the lower plastic 30.

[0165] The first transition surface 615 can form the first air passage S1 described above with the first sidewall 351 of the mounting groove 35. The second transition surface 616 can form the second air passage S2 described above with the second sidewall 352 of the mounting groove 35. The end surface of the first fixing portion 62 facing away from the main body 61 can form the third air passage S3 described above with the third sidewall 353 of the mounting groove 35. The end surface of the second fixing portion 63 facing away from the main body 61 can form the fourth air passage S4 described above with the fourth sidewall 354 of the mounting groove 35.

[0166] It is understood that the four avoidance grooves designed on each of the four sides of the support member 60 not only serve as a foolproofing measure during assembly, but also effectively prevent interference between the support member 60 and the latches 341 of the partition 34. This provides a clear functional distinction between the supporting and securing portions of the support member 60, thereby improving the assembly efficiency of the support member 60 and the lower plastic 30. Furthermore, while the support member 60 is secured by the latches 341 of the partition 34, the support surface of the support member 60 is maximized, effectively supporting the battery cell after the lower plastic 30 melts to prevent it from floating upward, and ensuring that gas within the battery cell can still be discharged through the explosion-proof valve 81.

[0167] In addition, each avoidance groove is connected to any one or more combinations of the first air channel S1, the second air channel S2, the third air channel S3, and the fourth air channel S4, which can increase the gas flow space in the installation groove 35, speed up the exhaust rate, and improve the exhaust reliability.

[0168] In the embodiment of the present application, any connection between the first fixing portion 62 and the first connecting surface 613 is a cambered transition R1. Any connection between the second fixing portion 63 and the second connecting surface 614 is a cambered transition R2. Any connection between the first fixing portion 62 and the first transition surface 615, and between the first fixing portion 62 and the second transition surface 616 is a cambered transition R3. Any connection between the second fixing portion 63 and the first transition surface 615, and between the second fixing portion 63 and the second transition surface 616 is a cambered transition R4. Cambered transition refers to a design that uses arcs or other arc-shaped structures to achieve a smooth transition at the intersection or between different areas on the surface of an object.

[0169] It can be understood that by designing any connection between each fixing part and each connecting surface and any connection between each fixing part and each transition surface to be a curved transition, the problem of the support member 60 scratching the lower plastic 30 during the use of the top cover assembly 100 can be effectively prevented, and the problem of the support member 60 shedding or the lower plastic 30 producing wire drawing can be avoided, and the reliability is better.

[0170] The above is a detailed introduction to the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of the present application. At the same time, for those skilled in the art, according to the idea of the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A top cover assembly, characterized in that: The top cover assembly includes a top cover, a lower plastic and a support member; The lower plastic includes a lower plastic body and a central boss, the lower plastic body and the top cover are stacked, the lower plastic body includes a first surface and a second surface, the first surface and the second surface are arranged opposite to each other in the thickness direction of the lower plastic body, the central boss is connected to the lower plastic body and protrudes relative to the second surface, the central boss includes a bottom surface and a first side surface, the bottom surface and the second surface are spaced apart in the thickness direction of the lower plastic, the first side surface is connected between the second surface and the bottom surface, and the first side surface is one of the two side surfaces of the central boss spaced apart along the length direction of the lower plastic; The lower plastic is provided with a mounting groove and a plurality of first exhaust holes. The mounting groove is located between the lower plastic body and the central boss, and the opening of the mounting groove is located on the first surface. The plurality of first exhaust holes are arranged at intervals along the width direction of the lower plastic. Each first exhaust hole is located on the first side surface and the bottom surface, and penetrates the central boss along the length direction and the thickness direction of the lower plastic. At least one of the plurality of first exhaust holes is communicated with the mounting groove. The support member is located in the mounting groove, and in the thickness direction of the top cover assembly, one side of the support member abuts against the bottom wall of the mounting groove, and the other side of the support member is used to support the top cover; The mounting groove includes a first side wall, which is a side wall of the mounting groove along the length direction of the lower plastic. A first air duct is formed between the first side wall and the support member. The first air duct is connected to at least one first exhaust hole among the multiple first exhaust holes. The size of the first air duct in the length direction of the lower plastic gradually decreases from the opening of the mounting groove toward the bottom wall of the mounting groove.

2. The top cover assembly according to claim 1, wherein: The support member includes a main body and a first fixing portion; The main body includes a first connecting surface, which is a surface of the main body in the width direction of the lower plastic. The first connecting surface includes a first sub-surface and two second sub-surfaces. The first sub-surface is connected between the two second sub-surfaces. In the thickness direction of the lower plastic, one second sub-surface, one first sub-surface, and another second sub-surface are arranged in sequence. The first fixing portion is connected to one of the first sub-surfaces. The first fixing portion and two of the second sub-surfaces on the same side are respectively surrounded to form two first avoidance grooves. In the two first avoidance grooves, each of the first avoidance grooves is communicated with the first air duct.

3. The top cover assembly according to claim 2, wherein: The support member further includes a second fixing portion; The main body further includes a second connecting surface, the second connecting surface and the first connecting surface are arranged opposite to each other in the width direction of the lower plastic, the second connecting surface includes a third sub-surface and two fourth sub-surfaces, the third sub-surface is connected between the two fourth sub-surfaces, and in the thickness direction of the lower plastic, the fourth sub-surface, the third sub-surface, and the fourth sub-surface are arranged in sequence; The second fixing portion is connected to one of the third sub-surfaces, and the second fixing portion and the two fourth sub-surfaces on the same side are respectively surrounded to form two second avoidance grooves. In the two second avoidance grooves, each of the second avoidance grooves is communicated with the first air duct.

4. The top cover assembly according to claim 3, wherein: The main body further includes a first transition surface and a second transition surface, wherein the first transition surface and the second transition surface are both connected between the first connecting surface and the second connecting surface and are arranged opposite to each other in the length direction of the lower plastic; Any connection between the first fixing portion and the first transition surface, and any connection between the first fixing portion and the second transition surface is a cambered transition; and / or, Any connection between the second fixing portion and the first transition surface, and any connection between the second fixing portion and the second transition surface is a cambered transition.

5. The top cover assembly according to claim 4, wherein: The central boss further includes a second side surface, the second side surface being connected between the second surface and the bottom surface and spaced apart from the first side surface in the length direction of the lower plastic; The lower plastic is provided with a plurality of second exhaust holes, which are spaced apart along the width direction of the lower plastic. Each second exhaust hole is located on the second side surface and the bottom surface, and passes through the central boss along the length direction and the thickness direction of the lower plastic. At least one of the plurality of second exhaust holes is connected to the mounting groove. The mounting groove also includes a second side wall, which is arranged opposite to the first side wall in the longitudinal direction of the lower plastic. A second air duct is formed between the second side wall and the support member, and the second air duct is connected to at least one second exhaust hole among the plurality of second exhaust holes. The size of the second air duct in the longitudinal direction of the lower plastic gradually decreases from the opening of the mounting groove toward the bottom wall of the mounting groove, and the second air duct is connected to each of the first avoidance grooves and / or each of the second avoidance grooves.

6. The top cover assembly according to claim 5, wherein: The mounting groove further includes a third side wall and a fourth side wall, wherein the third side wall and the fourth side wall are both connected between the first side wall and the second side wall, and the fourth side wall and the third side wall are arranged opposite to each other in the width direction of the lower plastic; A third air channel is formed between the third side wall and the support member, and the third air channel is connected to both the first air channel and the second air channel; and / or, A fourth air channel is formed between the fourth side wall and the support member, and the fourth air channel is communicated with both the first air channel and the second air channel.

7. The top cover assembly according to any one of claims 2 to 6, characterized in that: The lower plastic is provided with a cavity, the cavity is located between the lower plastic body and the central boss, and the opening of the cavity is located on the first surface. The lower plastic further includes a partition, the partition is connected to the bottom wall of the cavity and two opposite side walls of the cavity along the length direction of the lower plastic, and the partition can cooperate with the inner wall of the cavity to separate the mounting groove in the cavity; A buckle is provided at one end of the partition away from the bottom wall of the cavity, and at least part of the buckle is located in one of the two first avoidance grooves close to the top cover, and the buckle is used to fix the support member.

8. The top cover assembly according to any one of claims 1 to 6, wherein: The top cover is provided with an explosion-proof hole, which passes through the top cover along the thickness direction of the top cover and is used to connect with the explosion-proof valve; In the thickness direction of the top cover assembly, the projection of the support member on the top cover covers a portion of the explosion-proof hole; or, In the thickness direction of the top cover assembly, the projection of the support member on the top cover is spaced apart from the explosion-proof hole.

9. The top cover assembly according to any one of claims 1 to 6, wherein: The lower plastic is further provided with a plurality of third exhaust holes, which are arranged at intervals along the width direction of the lower plastic. Each of the third exhaust holes passes through the central boss along the thickness direction of the lower plastic. At least one of the plurality of third exhaust holes is connected to the mounting groove.

10. The top cover assembly according to any one of claims 1 to 6, characterized in that: The lower plastic further includes a first edge boss connected to the lower plastic body and protruding relative to the second surface, and the first edge boss is located at one end of the lower plastic body in the length direction; The first edge boss is provided with a plurality of fourth exhaust holes, which are spaced apart in the width direction of the lower plastic and arranged opposite to the plurality of first exhaust holes in the length direction of the lower plastic. Each of the fourth exhaust holes passes through the first edge boss along the length direction of the lower plastic.

11. The top cover assembly according to claim 5, wherein: The lower plastic further includes a second edge boss connected to the lower plastic body and protruding relative to the second surface, and the second edge boss is located at the other end of the lower plastic body in the longitudinal direction; The second edge boss is provided with a plurality of fifth exhaust holes, which are spaced apart in the width direction of the lower plastic and arranged opposite to the plurality of second exhaust holes in the length direction of the lower plastic. Each of the fifth exhaust holes passes through the second edge boss along the length direction of the lower plastic.

12. The top cover assembly according to claim 8, wherein: The lower plastic is provided with a first hole group. In the length direction of the lower plastic, the first hole group is located on one side of the central boss and is arranged adjacent to the central boss. The first hole group includes a sixth exhaust hole and a plurality of seventh exhaust holes. The sixth exhaust hole and the plurality of seventh exhaust holes both penetrate the lower plastic along the thickness direction of the lower plastic. The plurality of seventh exhaust holes are arranged in at least two first annular rings in a direction outward from the center line of the sixth exhaust hole in the width direction of the lower plastic and are sequentially spaced outside the sixth exhaust hole. In the at least two first annular rings, the plurality of seventh exhaust holes located in the same first annular ring are spaced apart. In the thickness direction of the top cover assembly, the projection of the explosion-proof hole on the lower plastic body at least covers a portion of the projection of the central boss on the lower plastic body and a portion of the projection of the plurality of seventh exhaust holes on the lower plastic body.

13. The top cover assembly according to claim 12, wherein: The dimension of each first annular ring along the width direction of the lower plastic is greater than the dimension of each first annular ring along the length direction of the lower plastic, and the dimension of each first annular ring along the length direction of the lower plastic gradually increases and then gradually decreases from one side of the width direction of the lower plastic to the other side of the width direction of the lower plastic.

14. The top cover assembly according to claim 12 or 13, wherein: The lower plastic further includes a convex portion, the convex portion being connected to both the lower plastic body and the central boss and being protruded relative to the second surface; the sixth exhaust hole and the plurality of seventh exhaust holes are both provided on the convex portion and penetrate the convex portion along the thickness direction of the lower plastic; The lower plastic is also provided with an air relief groove, the opening of the air relief groove is located on the first surface, and the air relief groove is recessed from the first surface toward the direction of the convex portion and the central boss. The air relief groove is also connected to the mounting groove, the sixth exhaust hole, and the multiple seventh exhaust holes. In the thickness direction of the top cover assembly, the projection of the air relief groove on the top cover can cover the explosion-proof hole.

15. A battery, characterized in that: The battery includes an electrode assembly, a shell and a top cover assembly according to any one of claims 1 to 14, wherein the top cover assembly is connected to the shell and is formed together with the shell to form a receiving space, and the electrode assembly is located in the receiving space.

16. An electrical device, characterized in that: The electric device comprises the battery as claimed in claim 15.

Images