Top cover assembly, battery monomer, battery and electric device

Abstract

The utility model relates to a top cover assembly, a battery monomer, a battery and a power utilization device. The top cover assembly comprises: a top cover having a first side, a second side and a liquid injection hole; the first sealing piece is arranged in the liquid injection hole, the end face, facing the first side, of the first sealing piece is provided with at least one stress release groove and a first reinforcing part, the stress release groove extends in the circumferential direction of the liquid injection hole, and the first reinforcing part is located between the two ends of the stress release groove; on the first side of the top cover, an annular welding mark surrounding the first sealing piece is formed between the top cover and the first sealing piece in a welding mode. And the welding starting position of the annular welding mark is located at the first reinforcing part. Thus, the stress releasing groove used for releasing the welding stress is formed in the first sealing piece, the first reinforcing part is arranged at the welding starting position, on one hand, the strength of the first sealing piece is improved, on the other hand, the welding area of the welding starting position is increased, and therefore the risk of generating weld beading is greatly reduced; and the cracking risk of the first sealing element is further reduced.

Description

Technical Field

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

[0002] In the manufacturing process of batteries (such as lithium-ion batteries), after the electrolyte filling and formation processes are completed, a seal needs to be placed inside the electrolyte filling hole on the cover plate. Then, laser sealing welding is performed on the gap between the seal and the cover plate to prevent electrolyte leakage from the electrolyte filling hole. During the welding process, stress is generated due to thermal contraction. If the welding stress is not released, it will remain in the weld, causing defects such as cracking and weld beads in the seal. Utility Model Content

[0003] Therefore, it is necessary to provide a top cover assembly, battery cell, battery, and electrical device that can improve defects such as cracking and weld beads caused by welding stress in the sealing parts during the welding process, in order to address the above problems.

[0004] On one hand, this application provides a top cover assembly, including:

[0005] The top cover has a first side, a second side opposite to the first side, and an injection hole penetrating the surfaces of the first and second sides; and

[0006] A first sealing element is disposed in the injection hole. The first sealing element has at least one stress relief groove and a first reinforcing part on the end face facing the first side. The stress relief groove extends circumferentially along the injection hole, and the first reinforcing part is located between the two ends of the stress relief groove.

[0007] Wherein, on the first side of the top cover, the top cover and the first sealing element are welded together to form an annular weld mark surrounding the first sealing element; the welding start position of the annular weld mark is located at the first reinforcing part.

[0008] In some embodiments, the first side surface of the top cover also has a pre-welding position and a welding termination position located on opposite sides of the welding start position of the annular weld mark. A pre-welding weld mark is formed by welding the pre-welding position and the welding start position of the annular weld mark, and a termination weld mark is formed by welding the welding termination position and the welding start position of the annular weld mark. The pre-welding weld mark and the termination weld mark do not coincide with the annular weld mark.

[0009] In some embodiments, the first seal has a second reinforcement on its end face facing the first side, the first reinforcement and the second reinforcement are arranged circumferentially spaced along the first seal, and the stress relief groove is divided into at least two arc-shaped grooves by the first reinforcement and the second reinforcement.

[0010] In some embodiments, the height dimension of the second reinforcement in the axial direction of the first seal is smaller than the height dimension of the first reinforcement in the axial direction of the first seal.

[0011] In some embodiments, the height dimension a2 of the second reinforcement in the axial direction of the first seal satisfies: 0.3h ≤ a2 < h, where h represents the depth dimension of the stress relief groove.

[0012] In some embodiments, the width of the first reinforcement in the circumferential direction of the first seal is greater than the width of the second reinforcement in the circumferential direction of the first seal.

[0013] In some embodiments, the width b of the second reinforcement in the circumferential direction of the first seal satisfies: 0.5c ≤ b ≤ 2c, where c represents the width of the stress relief groove.

[0014] In some embodiments, the first seal includes a central region located inside the stress relief groove and an edge region located outside the stress relief groove;

[0015] The edge region has a radial dimension f ≥ 0.3 mm in the first seal.

[0016] In some embodiments, the first seal includes a central region located inside the stress relief groove and an edge region located outside the stress relief groove; the angle between the groove wall of the stress relief groove near the edge region and a dummy plane is a first angle g1, and the dummy plane is perpendicular to the axis of the first seal; wherein, 45°≤g1≤90°.

[0017] On the other hand, this application provides a battery cell, including a housing, a cell assembly, and a top cover assembly as described in any of the above embodiments;

[0018] The housing has a receiving cavity and an opening communicating with the receiving cavity. The battery cell assembly is received in the receiving cavity. The top cover is disposed on the opening of the housing, and the second side of the top cover faces into the receiving cavity.

[0019] On the other hand, this application provides a battery cell, including a housing, a cell assembly and a first sealing member, wherein the housing has a receiving cavity and a liquid injection hole penetrating the inner wall and the outer wall of the housing, and the battery assembly is received in the receiving cavity;

[0020] The first sealing element is disposed in the injection hole, and the end face of the first sealing element facing the outer wall of the housing has at least one stress relief groove and a first reinforcing part. The stress relief groove extends circumferentially along the injection hole, and the first reinforcing part is located between the two ends of the stress relief groove.

[0021] Wherein, on the outer wall of the housing, the housing and the first sealing element are welded together to form an annular weld mark surrounding the first sealing element; the welding start position of the annular weld mark is located at the first reinforcing part.

[0022] On the other hand, this application provides a battery including a battery cell as described in any of the above embodiments.

[0023] On the other hand, an electrical device includes a battery cell as described in any of the above embodiments; or includes a battery as described in any of the above embodiments.

[0024] Compared with the prior art, this application has the following beneficial effects:

[0025] In the aforementioned top cover assembly, battery cell, battery, and electrical device, weld beads are generated at the weld fusion site during welding of the first seal and the top cover, especially at the welding start point. The weld beads are not firmly bonded to the first seal, easily causing stress concentration and leading to cracking of the first seal. In this application, a stress relief groove is formed on the first seal to release welding stress, and a first reinforcing part is provided at the welding start point. This increases the strength of the first seal and the welding area at the welding start point, thereby significantly reducing the risk of weld beads and consequently reducing the risk of cracking of the first seal. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of a single battery cell in one embodiment of this application;

[0027] Figure 2 for Figure 1 The front view of the top cover assembly of the shown battery cell;

[0028] Figure 3 for Figure 2 A schematic diagram of the top cover structure of the top cover assembly shown;

[0029] Figure 4 for Figure 2 The image shows a magnified view of the top cover assembly at point A.

[0030] Figure 5 for Figure 2 A cross-sectional view of the top cover assembly shown;

[0031] Figure 6 for Figure 5The diagram shows a partial enlarged view of the top cover assembly at point B.

[0032] Figure 7 for Figure 2 A schematic diagram of the structure of the first seal of the top cover assembly is shown;

[0033] Figure 8 This is a schematic diagram of the structure of the first sealing element in another embodiment of this application;

[0034] Figure 9 This is a schematic diagram of the structure of the first sealing element in yet another embodiment of this application;

[0035] Figure 10 This is a schematic diagram of the structure of the first sealing element in another embodiment of this application. Detailed Implementation

[0036] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0037] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0038] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0039] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0040] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0041] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0042] One embodiment of this application provides an electrical device that uses a battery or battery cell as its power source. Specifically, the electrical device can be a vehicle, mobile phone, portable device, laptop computer, ship, spacecraft, electric toy, and power tool, etc. Vehicles can be gasoline-powered vehicles, natural gas-powered vehicles, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc.; spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application embodiment does not impose any special limitations on the above-mentioned electrical device.

[0043] The battery mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity. In some embodiments, the battery can be a battery pack, which includes a housing and battery cells housed within the housing. The housing provides space for the battery cells and can have various structures and shapes, such as a cuboid. The battery may contain multiple battery cells, which can be connected in series, parallel, or a combination thereof. A combination of series and parallel connections refers to multiple battery cells being connected in both series and parallel configurations. Multiple battery cells can be directly connected in series, parallel, or a combination thereof, and then the entire assembly of the multiple battery cells is housed within the housing. Alternatively, in some embodiments, the battery may consist of multiple battery cells first connected in series, parallel, or a combination thereof to form a battery module, and then these battery modules are connected in series, parallel, or a combination thereof to form a whole, which is then housed within the housing. The battery may also include other structures; for example, it may include a busbar for electrical connection between multiple battery cells. Each battery cell can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these.

[0044] The specific structure of the battery cell will be described in detail below with reference to the accompanying drawings. Figure 1 This is a schematic diagram of the structure of a single battery cell in an embodiment of this application; Figure 2 for Figure 1 The front view of the top cover assembly of the shown battery cell;

[0045] Figure 3 for Figure 2 A schematic diagram of the top cover structure of the top cover assembly shown; Figure 4 for Figure 2 The image shows a magnified view of the top cover assembly at the injection port. Figure 5 for Figure 2 A cross-sectional view of the top cover assembly shown; Figure 6 for Figure 5 The diagram shows a partial enlarged view of the top cover assembly at point B. Figure 7 for Figure 2 A schematic diagram of the structure of the first seal of the top cover assembly is shown; Figure 8 This is a schematic diagram of the structure of the first sealing element in another embodiment of this application; Figure 9 This is a schematic diagram of the structure of the first sealing element in yet another embodiment of this application; Figure 10 This is a schematic diagram of the structure of the first sealing element in another embodiment of this application. For ease of description and understanding, the accompanying drawings only show the structures relevant to this application.

[0046] Please see Figure 1As shown, this application provides a battery cell including a housing 200, a cell assembly, and a top cover assembly 100. The housing 200 has a receiving cavity and an opening communicating with the receiving cavity. The cell assembly is received within the receiving cavity of the housing 200, and the top cover assembly 100 is disposed on the opening of the housing 200, thereby enclosing the cell assembly within the housing 200.

[0047] Please see Figures 2 to 6 As shown, the top cover assembly 100 includes a top cover 10 and a first seal 20. The top cover 10 has a first side 101, a second side 103, and an injection hole 105. The first side 101 and the second side 103 are opposite to each other, and the injection hole 105 penetrates the surfaces of the first side 101 and the second side 103 of the top cover 10. The first seal 20 is disposed within the injection hole 105, and the end face of the first seal 20 facing the first side 101 has at least one stress relief groove 21 (see...). Figure 7 ) and the first reinforced section 23 (see Figure 7 The stress relief groove 21 extends circumferentially along the injection hole 105. The first reinforcing part 23 is located between the two ends of the stress relief groove 21. Specifically, on the first side 101 of the top cover 10, an annular weld mark 30 is formed by welding the top cover 10 and the first sealing member 20. The welding start position 31 of the annular weld mark 30 is located at the first reinforcing part 23. Optionally, the first sealing member 20 can be an aluminum nail. Of course, in other embodiments, the first sealing member 20 can also be made of other materials, as long as it can be welded to the top cover 10 and seal the injection hole 105; no special limitation is made here.

[0048] Thus, when welding the first seal 20 to the top cover 10, weld beads will form at the weld fusion point, especially at the weld initiation position 31. The weld beads are not firmly bonded to the first seal 20, which can easily cause stress concentration and lead to cracking of the first seal 20. In this application, a stress relief groove 21 for releasing welding stress is formed on the first seal 20, and a first reinforcing part 23 is provided at the weld initiation position 31. On the one hand, the strength of the first seal 20 is increased, and on the other hand, the welding area at the weld initiation position 31 is increased, thereby greatly reducing the risk of weld beads and thus reducing the risk of cracking of the first seal 20.

[0049] It should be noted that the first reinforcing part 23 is provided between the two ends of the stress relief groove 21, which can greatly reduce the deformation of the first seal 20 caused by the opening of the stress relief groove 21, that is, avoid the first seal 20 from generating large deformation, which is beneficial to improving the assembly and welding quality of the first seal 20.

[0050] It is understood that the stress relief groove 21 can be a continuous segment (i.e., the number of stress relief grooves 21 is one), and the first reinforcing part 23 is located between the two ends of the same stress relief groove 21 segment. The stress relief groove 21 can also be two or more segments (i.e., the number of stress relief grooves 21 is multiple), and the first reinforcing part 23 is located between the ends of two adjacent stress relief groove segments 21 in the circumferential direction of the first seal 20.

[0051] In the embodiments of this application, the surface of the first side 101 of the top cover 10 further has pre-welding positions 32 and welding termination positions 34 located on opposite sides of the welding start position 31 of the annular weld mark 30. A pre-welding weld mark 33 is formed between the pre-welding position 32 and the welding start position 31 of the annular weld mark 30. A termination weld mark 35 is formed between the welding termination position 34 and the welding start position 31 of the annular weld mark 30. The pre-welding weld mark 33 and the termination weld mark 35 do not coincide with the annular weld mark 30.

[0052] Thus, during the welding operation, the laser welding mechanism first performs pre-welding from the pre-welding position 32 to the welding start position 31. After the laser welding power stabilizes, the laser welding mechanism welds to the welding start position 31, at which point a pre-weld mark 33 is formed between the pre-welding position 32 and the welding start position 31. Then, the laser welding mechanism performs formal welding along the circumference of the first sealing element 20 and finally returns to the welding start position 31, at which point an annular weld mark 30 is formed. Next, the laser welding mechanism welds from the welding start position 31 to the welding end position 34 until the laser welding power drops to zero, at which point a termination weld mark 35 is formed between the welding start position 31 and the welding end position 34. Since the laser welding power is unstable (i.e., too high or too low) in the initial and final stages of welding, reserving the pre-weld mark 33 and the termination weld mark 35 can serve as a transition between stages where the laser welding power is too high or too low. After the welding laser stabilizes, welding is performed on the actual position that needs to be welded (i.e., welding forms the aforementioned annular weld mark 30), which helps to ensure better welding quality.

[0053] It should be noted that because the stress relief groove 21 is provided on the first sealing element 20, the welding area is reduced, resulting in the need for lower laser welding power and a longer pre-weld mark 33, leading to higher welding costs and safety risks. In this application, a first reinforcing part 23 is provided at the welding start position 31, thereby increasing the welding area at the welding start position 31, which helps to reduce the length of the pre-weld mark 33, thus reducing welding costs and safety risks.

[0054] Please see Figure 8As shown, in some embodiments, the first seal 20 also has a second reinforcing portion 25 on the end face facing the first side 101. The first reinforcing portion 23 and the second reinforcing portion 25 are arranged at intervals along the circumference of the first seal 20. The stress relief groove 21 is divided into at least two arc-shaped grooves by the first reinforcing portion 23 and the second reinforcing portion 25. Thus, the simultaneous provision of the first reinforcing portion 23 and the second reinforcing portion 25 is beneficial to improving the strength enhancement effect of the first seal 20 and further reducing the deformation of the first seal 20 caused by the opening of the stress relief groove 21.

[0055] It should be noted that the number of second reinforcing parts 25 can be one or more. Preferably, the number of second reinforcing parts 25 is one or two. Since the heat dissipation area decreases during welding at the locations where the first reinforcing part 23 and the second reinforcing part 25 are provided, the heat dissipation effect varies at different locations, resulting in uneven thermal stress and increasing the risk of cracking of the first seal 20 during welding. Therefore, having one or two second reinforcing parts 25 is optimal, as it significantly reduces the deformation of the first seal 20 without significantly increasing the risk of cracking during welding. Optionally, the first reinforcing part 23 and each of the second reinforcing parts 25 are evenly distributed along the circumference of the first seal 20.

[0056] Specifically, when the number of the second reinforcing section 25 is one (see...) Figure 8 A first reinforcing part 23 and a second reinforcing part 25 divide the stress relief groove 21 into two arc-shaped grooves. When the number of second reinforcing parts 25 is two (see...), Figure 9 A first reinforcing part 23 and two second reinforcing parts 25 divide the stress relief groove 21 into three arc-shaped grooves.

[0057] Please see Figure 10 As shown, in a specific embodiment, the height of the second reinforcing part 25 in the axial direction of the first sealing member 20 is smaller than the height of the first reinforcing part 23 in the axial direction of the first sealing member 20. In other words, reducing the height of the second reinforcing part 25 in the axial direction of the first sealing member 20 helps to reduce the impact of the second reinforcing part 25 on the heat dissipation area during welding, thereby reducing the risk of cracking of the first sealing member during welding.

[0058] Optionally, the height a1 of the first reinforcing part 23 in the axial direction of the first sealing member 20 is equal to the depth h of the stress relief groove 21. The height a2 of the second reinforcing part 25 in the axial direction of the first sealing member 20 satisfies: 0.3h ≤ a2 < h, where h represents the depth of the stress relief groove 21. In this way, while ensuring the strength of the first sealing member 20 is enhanced, the heat dissipation area during welding is ensured to meet the heat dissipation requirements.

[0059] In a specific embodiment, the width of the first reinforcing part 23 in the circumferential direction of the first sealing member 20 is greater than the width of the second reinforcing part 25 in the circumferential direction of the first sealing member 20. That is, reducing the width of the second reinforcing part 25 in the circumferential direction of the first sealing member 20 helps to reduce the impact of the second reinforcing part 25 on the heat dissipation area during welding, thereby reducing the risk of cracking of the first sealing member 20 during welding.

[0060] Optionally, the width b of the second reinforcing part 25 in the circumferential direction of the first sealing member 20 satisfies: 0.5c ≤ b ≤ 2c, where c represents the width of the stress relief groove 2121. In this way, while ensuring the strength of the first sealing member 20 is enhanced, the heat dissipation area during welding is ensured to meet the heat dissipation requirements.

[0061] Specifically, in this embodiment, the first seal 20 includes a central region 26 located inside the stress relief groove 21 and an edge region 27 located outside the stress relief groove 21. The radial dimension f of the edge region 27 of the first seal 20 is ≥0.3mm. If the radial dimension f of the edge region 27 of the first seal 20 is too small, it will cause the molten pool to flow along the edge of the stress relief groove 21 during welding, forming weld beads. Designing the radial dimension f of the edge region 27 of the first seal 20 to be greater than or equal to 0.3mm can greatly reduce the risk of weld beads forming during welding, further reducing the risk of cracking of the first seal 20.

[0062] Specifically, in this embodiment, the first seal 20 includes a central region 26 located inside the stress relief groove 21 and an edge region 27 located outside the stress relief groove 21. The angle between the groove wall of the stress relief groove 21 near the edge region 27 and a dummy plane is a first included angle g1. This dummy plane is perpendicular to the axis of the first seal 20, and the first included angle g1 satisfies: 45° ≤ g1 ≤ 90°. Thus, designing the first included angle g1 to be greater than or equal to 45° and less than or equal to 90° avoids stress concentration caused by an excessively small first included angle g1.

[0063] Please see Figure 5 and Figure 6 As shown in the embodiment of this application, the injection hole 105 on the top cover 10 includes a first hole segment 1051 and a second hole segment 1053 coaxially arranged and communicating with each other. The first hole segment 1051 penetrates the surface of the first side 101 of the top cover 10, and the second hole segment 1053 penetrates the surface of the second side 103 of the top cover 10. The diameter of the first hole segment 1051 is larger than the diameter of the second hole segment 1053, thereby forming a stepped surface 1055 between the first hole segment 1051 and the second hole segment 1053. The first sealing member 20 is placed in the first hole segment 1051 and supported on the stepped surface 1055.

[0064] Optionally, the diameter of the first orifice 1051 gradually decreases from the end furthest from the second orifice 1053 to the end closest to the second orifice 1053. The diameter d1 of the end of the first orifice 1051 furthest from the second orifice 1053 is 5 mm to 10 mm. The diameter d2 of the end of the first orifice 1051 closest to the second orifice 1053 is 4.5 mm to 9.5 mm. The diameters at both ends of the first orifice 1051 can be designed according to the size of the top cap 10 and the injection efficiency; d1 can be 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, or 10 mm, and d2 can be 4.5 mm, 5.5 mm, 6.5 mm, 7.5 mm, 8.5 mm, or 9.5 mm.

[0065] Furthermore, the difference between the diameter d1 of the end of the first hole segment 1051 furthest from the second hole segment 1053 and the diameter d2 of the end of the first hole segment 1051 closest to the second hole segment 1053 is less than or equal to 1 mm. This ensures that the inner wall of the first hole segment 1051 guides the first seal 20 when it is inserted into the first hole segment 1051, while also preventing the step surface 1055 from being too small to adequately support the first seal 20.

[0066] In a specific embodiment, the diameter of the first sealing member 20 gradually decreases in the direction from the first side 101 to the second side 103, so that the outer peripheral surface of the first sealing member 20 matches the inner wall of the first hole segment 1051.

[0067] Optionally, the diameter d3 of the end of the first seal 20 facing the first side 101 satisfies: d1-d3≥0.2mm, thereby ensuring that the gap between the end of the first seal 20 facing the first side 101 and the inner wall of the first hole section 1051 is not less than 0.1mm, ensuring that the welding requirements of the first seal 20 and the top cover 10 are met, which is beneficial to improving the welding quality.

[0068] Optionally, the diameter d4 of the end of the first seal 20 away from the first side 101 satisfies: 0.1mm≤d2-d4≤0.5mm, so that the gap between the first seal 20 and the inner wall of the end of the first hole segment 1051 near the second hole segment 1053 is large enough to avoid the first seal 20 from being improperly assembled and causing the first seal 20 to bulge outward.

[0069] In a specific embodiment, the top cover assembly further includes a second sealing element 50, which is sealed within the second section 1053 of the injection hole 105. Thus, the first sealing element 20 and the second sealing element 50 together achieve a seal on the injection hole 105. Optionally, the second sealing element 50 is a rubber stud, which fits tightly against the second section 1053 of the injection hole 105, thereby achieving a seal on the second section 1053 of the injection hole 105 through the elastic deformation of the rubber stud.

[0070] It should be noted that the injection hole 105 is not limited to being formed on the top cover 10. In other embodiments, the injection hole 105 may also be formed on the housing. The embodiments where the injection hole 105 is formed on the housing are similar to the embodiments where the injection hole 105 is formed on the top cover 10, with the following differences:

[0071] The housing has a receiving cavity and a liquid injection hole 105 penetrating the inner and outer walls of the housing. A first sealing member 20 is disposed within the liquid injection hole 105. The end face of the first sealing member 20 facing the outer wall of the housing has at least one stress relief groove 21 and a first reinforcing portion 23. The stress relief groove 21 extends circumferentially along the liquid injection hole 105, and the first reinforcing portion 23 is located between the two ends of the stress relief groove 21. An annular weld mark 30 is welded between the housing and the first sealing member 20 on the outer wall of the housing. The welding start position 31 of the annular weld mark 30 is located at the first reinforcing portion 23.

[0072] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0073] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A top cover assembly, characterized in that, include: The top cover (10) has a first side (101), a second side (103) opposite to the first side (101), and an injection hole (105) penetrating the surface of the first side (101) and the surface of the second side (103); and A first sealing element (20) is disposed in the injection hole (105). The first sealing element (20) has at least one stress relief groove (21) and a first reinforcing part (23) on the end face facing the first side (101). The stress relief groove (21) extends circumferentially along the injection hole (105), and the first reinforcing part (23) is located between the two ends of the stress relief groove (21). Wherein, on the first side (101) of the top cover (10), the top cover (10) and the first seal (20) are welded together to form an annular weld mark (30) surrounding the first seal (20); the welding start position (31) of the annular weld mark (30) is located at the first reinforcing part (23).

2. The top cover assembly according to claim 1, characterized in that, The first side (101) surface of the top cover (10) also has a pre-welding position (32) and a welding termination position (34) located on opposite sides of the welding start position (31) of the annular welding mark (30). A pre-welding mark (33) is formed by welding the pre-welding position (32) and the welding start position (31) of the annular welding mark (30). A termination mark (35) is formed by welding the welding termination position (34) and the welding start position (31) of the annular welding mark (30). The pre-welding mark (33) and the termination mark (35) do not coincide with the annular welding mark (30).

3. The top cover assembly according to claim 1, characterized in that, The first seal (20) also has a second reinforcing part (25) on the end face facing the first side (101). The first reinforcing part (23) and the second reinforcing part (25) are arranged circumferentially spaced along the first seal (20). The stress relief groove (21) is divided into at least two arc-shaped grooves by the first reinforcing part (23) and the second reinforcing part (25).

4. The top cover assembly according to claim 3, characterized in that, The height dimension of the second reinforcing part (25) in the axial direction of the first seal (20) is smaller than the height dimension of the first reinforcing part (23) in the axial direction of the first seal (20).

5. The top cover assembly according to claim 4, characterized in that, The height dimension a2 of the second reinforcing part (25) in the axial direction of the first seal (20) satisfies: 0.3h≤a2<h, where h represents the depth dimension of the stress relief groove (21).

6. The top cover assembly according to claim 3, characterized in that, The width dimension of the first reinforcing part (23) in the circumferential direction of the first seal (20) is greater than the width dimension of the second reinforcing part (25) in the circumferential direction of the first seal (20).

7. The top cover assembly according to claim 6, characterized in that, The width dimension b of the second reinforcing part (25) in the circumferential direction of the first sealing member (20) satisfies: 0.5c≤b≤2c, where c represents the width dimension of the stress relief groove (21).

8. The top cover assembly according to claim 1, characterized in that, The first seal (20) includes a central region (26) located inside the stress relief groove (21) and an edge region (27) located outside the stress relief groove (21); The edge region (27) has a radial dimension f of ≥0.3 mm in the first seal (20).

9. The top cover assembly according to claim 1, characterized in that, The first seal (20) includes a central region (26) located inside the stress relief groove (21) and an edge region (27) located outside the stress relief groove (21); the angle between the groove wall of the stress relief groove (21) near the edge region (27) and a dummy plane is a first angle g1, and the dummy plane is perpendicular to the axis of the first seal (20); wherein, 45°≤g1≤90°.

10. A single battery cell, characterized in that, Includes a housing, a battery cell assembly, and a top cover assembly as described in any one of claims 1 to 9; The housing has a receiving cavity and an opening communicating with the receiving cavity. The battery cell assembly is received in the receiving cavity. The top cover (10) is placed over the opening of the housing, and the second side (103) of the top cover (10) faces the receiving cavity.

11. A single battery cell, characterized in that, The battery assembly includes a housing, a battery cell assembly, and a first seal (20). The housing has a receiving cavity and a liquid injection hole (105) penetrating the inner and outer walls of the housing. The battery assembly is housed in the receiving cavity. The first sealing member (20) is disposed in the injection hole (105). The first sealing member (20) has at least one stress relief groove (21) and a first reinforcing part (23) on the end face facing the outer wall of the housing. The stress relief groove (21) extends circumferentially along the injection hole (105), and the first reinforcing part (23) is located between the two ends of the stress relief groove (21). Wherein, on the outer wall of the housing, the housing and the first seal (20) are welded together to form an annular weld mark (30) surrounding the first seal (20); the welding start position (31) of the annular weld mark (30) is located at the first reinforcing part (23).

12. A battery, characterized in that, Includes the battery cell as described in claim 10 or 11.

13. An electrical appliance, characterized in that, It includes the battery cell as described in claim 10 or 11; or, it includes the battery as described in claim 12.

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