Cover plate assembly, battery and electric device

Abstract

The invention provides a cover plate assembly, a battery and a power utilization device, and relates to the technical field of batteries, the cover plate assembly comprises a cover plate body, a first insulating part and a terminal assembly, the cover plate body is provided with a first surface, a second surface and a mounting hole; the first insulating part is arranged on one side of the cover plate body; the terminal assembly comprises an electrode terminal, a sealing piece and a fixing piece, the electrode terminal comprises a first electric connecting part and a second electric connecting part, the first electric connecting part is arranged on the first surface and covers the mounting hole, the sealing piece is pressed between the first electric connecting part and the first surface, and the second electric connecting part penetrates through the sealing piece and is arranged in the mounting hole; the fixing piece is connected to the second electric connecting part, and at least part of the fixing piece can abut against the first insulating piece under the action of the compression resilience force of the sealing piece. Therefore, the electrode terminal is pressed and fixed on the cover plate assembly under the combined action of the fixing piece and the sealing piece, the riveting or welding procedure is omitted, the processing procedure of the cover plate assembly is simplified, and the processing cost of the cover plate assembly is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular, to a cover plate assembly, a battery, and an electrical device. Background Art

[0002] As one of the core components of a battery, the cell cover plate plays multiple roles. With the increasing requirements for battery performance and cost, the requirements for the lightweight, reliability, and low-cost manufacturing of the cover plate have also become the competitive points in the industry.

[0003] In the related art, the cover plate forming process is relatively complex, and the connection is usually achieved by riveting or welding. For example, the connection between the pole column and the cover plate results in a complex forming process of the cover plate and a high cost. In addition, the riveting or welding process is prone to thermal deformation or microcracks, which may cause a decrease in sealing performance or an increase in resistance during long-term use, affecting the performance of the battery. Therefore, how to provide a cover plate with low cost and high reliability is a technical problem that urgently needs to be solved in the battery field. Summary of the Invention

[0004] The purpose of the present application is to provide a cover plate assembly, a battery, and an electrical device to solve the technical problems of complex processing technology and high cost of the cover plate in the prior art.

[0005] To achieve the above purpose, the technical solution adopted in the present application is as follows:

[0006] In a first aspect, a cover plate assembly of the present application includes: a cover plate body, a first insulating member, and a terminal assembly. The cover plate body has a first surface and a second surface oppositely arranged along its thickness direction, and a mounting hole penetrating the first surface and the second surface; the first insulating member is disposed on one side of the cover plate body having the second surface; the terminal assembly includes an electrode terminal, a sealing member, and a fixing member. Among them, the electrode terminal includes a first electrical connection portion and a second electrical connection portion. The first electrical connection portion is disposed on the first surface and covers the mounting hole. The sealing member is pressed between the first electrical connection portion and the first surface. The second electrical connection portion passes through the sealing member and is disposed in the mounting hole. The fixing member is connected to the second electrical connection portion. Under the action of the compression resilience of the sealing member, at least a part of the fixing member can abut against the first insulating member.

[0007] In an embodiment of the present application, the first insulating member has a third surface facing away from the cover plate body. The fixing member extends in a direction parallel to the third surface and is connected to the second electrical connection portion. The two ends of the fixing member in the length direction protrude from the second electrical connection portion. Under the action of the compression resilience of the sealing member, the part of the fixing member protruding from the second connection portion abuts against the third surface of the first insulating member.

[0008] In the embodiment of the present application, the second electrical connection part is provided with a through hole for accommodating a fixing member. The central axis of the through hole extends in a direction parallel to the third surface. Along the direction perpendicular to the third surface, the through hole has a first side surface and a second side surface, wherein the second side surface is closer to the first electrical connection part than the first side surface. The fixing member is inserted through the through hole and both ends of the fixing member protrude from the through hole.

[0009] Under the action of the compression resilience of the seal, the part of the fixing member protruding from the through hole abuts against the third surface of the first insulating member, and the part of the fixing member located inside the through hole abuts against the first side surface.

[0010] In the embodiment of the present application, on a plane parallel to the third surface and along a direction perpendicular to the central axis of the through hole, the width of the fixing member is smaller than the width of the through hole. Along the central axis direction of the through hole, the length of the fixing member is greater than the length of the through hole. The length of the two ends of the fixing member in the length direction protruding from the through hole is h, and it satisfies: 0.5 mm ≤ h ≤ 10 mm.

[0011] In the embodiment of the present application, the compression rate of the seal satisfies: wherein, f is the thickness of the seal along its axial direction before being compressed, and g is the thickness of the seal along its axial direction after being compressed.

[0012] In the embodiment of the present application, along the axial direction of the mounting hole, the distance between the first side surface of the through hole and the second electrical connection surface of the second electrical connection part is a, and it satisfies: 1 mm ≤ a ≤ 3 mm, and / or

[0013] the distance between the second side surface of the through hole and the first electrical connection surface of the first electrical connection part is b, and it satisfies: 1.5 mm ≤ b ≤ 3 mm.

[0014] In the embodiment of the present application, the maximum tensile resistance of the fixing member is not less than the compression resilience of the seal.

[0015] In the embodiment of the present application, it further includes: a second insulating member, sleeved outside the seal.

[0016] In a second aspect, the present application further provides a battery, including at least one battery cell. The battery cell includes: a housing, an electrode assembly, and the cover plate assembly according to any one of the first aspect. The housing has an opening, the cover plate assembly is covered on the opening of the housing, and the electrode assembly is accommodated in the housing.

[0017] In a third aspect, the present application further provides an electrical device, including the battery according to the second aspect.

[0018] Based on the above technical solutions, the cover plate assembly, the battery, and the electrical device of the present application at least have the following beneficial technical effects:

[0019] For the cover plate assembly provided by the present application, a seal is pressed between the first electrical connection portion of the electrode terminal and the first surface of the cover plate body. Thus, when the first electrical connection portion applies a pressure to the seal towards the first surface, the seal is compressed to generate a resilience force in the direction opposite to the compression direction. The compression resilience force of the seal applies a force to the electrode terminal in the direction away from the cover plate body, causing the electrode terminal to have a tendency to move away from the cover plate body. A fixing member is connected to the second electrical connection portion of the electrode terminal, and at least a part of the fixing member can abut against the first insulating member under the action of the compression resilience force of the seal, applying a force to the electrode terminal opposite to the compression resilience force of the seal, which can limit the movement of the electrode terminal away from the cover plate body. The compression resilience force of the seal and the reaction force of the fixing member form a balance, so that the electrode terminal is tightly fixed on the cover plate assembly under the combined action of the fixing member and the seal, eliminating the riveting or welding process, simplifying the processing process of the cover plate assembly, and reducing the processing cost of the cover plate assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 is a schematic three-dimensional structure diagram of the cover plate assembly provided by the embodiment of the present application.

[0022] Figure 2 is a schematic bottom structure diagram of the cover plate assembly provided by the embodiment of the present application.

[0023] Figure 3 is an exploded structure diagram of the cover plate assembly provided by the embodiment of the present application.

[0024] Figure 4 is a top view of the cover plate assembly provided by the embodiment of the present application.

[0025] Figure 5 is Figure 4 the sectional view taken along A-A in

[0026] Figure 6 is Figure 5 a partial enlarged view of

[0027] Figure 7 is Figure 4 the sectional view taken along B-B in

[0028] Figure 8 is a partial structure diagram of the first surface of the cover plate body in the cover plate assembly provided by the embodiment of the present application.

[0029] In the figure: 10 - cover plate body; 20 - terminal assembly; 30 - second insulating member; 40 - first insulating member; 100 - mounting hole; 101 - first surface; 102 - second surface; 103 - third surface; 200 - electrode terminal; 201 - fixing member; 202 - first electrical connection portion; 203 - second electrical connection portion; 204 - through hole; 205 - seal; 2021 - first electrical connection surface; 2031 - second electrical connection surface; 2041 - first side surface; 2042 - second side surface; 401 - perforation; 402 - insulating convex ring. Detailed implementation manners

[0030] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application clearer and more understandable, the following further details this application in combination with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application.

[0031] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0032] It should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to this application.

[0033] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this application, "a plurality of" means two or more, unless otherwise specifically defined.

[0034] The technical solutions of this application will be described in detail below with reference to the accompanying drawings of the specification.

[0035] Please refer to Figure 1 、 Figure 2 and Figure 3, a cover plate assembly provided by the present application includes: a cover plate body 10, a first insulating member 40, and a terminal assembly 20. The cover plate body 10 has a first surface 101 and a second surface 102 oppositely arranged along its thickness direction, and a mounting hole 100 penetrating through the first surface 101 and the second surface 102. The first insulating member 40 is disposed on the side of the cover plate body 10 having the second surface 102. The terminal assembly 20 includes an electrode terminal 200, a sealing member 205, and a fixing member 201. Among them, the electrode terminal 200 includes a first electrical connection portion 202 and a second electrical connection portion 203. The first electrical connection portion 202 is disposed on the first surface 101 and covers the mounting hole 100. The sealing member 205 is pressed between the first electrical connection portion 202 and the first surface 101. The second electrical connection portion 203 passes through the sealing member 205 and is disposed in the mounting hole 100. The fixing member 201 is connected to the second electrical connection portion 203. Under the action of the compression resilience of the sealing member 205, at least a part of the fixing member 201 abuts against the first insulating member 40.

[0036] It should be noted that the cover plate body 10 is a structural member for sealing the battery cell housing so as to seal the electrode assembly inside the housing. In some embodiments, the cover plate body 10 may be a light aluminum plate. The mounting hole 100 of the cover plate body 10 is for mounting the electrode terminal 200 so as to lead the electrical energy of the electrode assembly located inside the housing to the outside of the cover plate assembly through the electrode terminal 200.

[0037] The first insulating member 40 may be a plate-like structure made of plastic material. A through hole 401 coaxially arranged with the mounting hole 100 is provided on the first insulating member 40 to facilitate the second electrical connection portion 203 of the electrode terminal 200 to sequentially pass through the mounting hole 100 and the through hole 401 and be electrically connected to the electrode assembly. In some embodiments, the end portion of the second electrical connection portion 203 facing the electrode assembly protrudes from the first insulating member 40. By providing the first insulating member 40 on one side of the cover plate body 10, the cover plate body 10 can be insulated from the electrode assembly inside the housing and the cover plate body 10 can be insulated from the electrode terminal 200 through the first insulating member 40. In some embodiments, the insulating member 40 is provided with an insulating convex ring 402 on the edge of the hole wall around the through hole 401. The insulating convex ring 402 is inserted into the mounting hole 100 of the cover plate body 10 for insulating the electrode terminal 200 and the cover plate body 10.

[0038] The housing has an accommodation space for accommodating the electrode assembly. At least one end of the housing has an opening to communicate the accommodation space inside the housing and the outside through the opening. The electrode assembly may be formed by stacking or winding a positive electrode plate, a negative electrode plate, and a separator located between the positive electrode plate and the negative electrode plate.

[0039] The first electrical connection portion 202 can be used for electrically connecting with an external adapter piece, and the second electrical connection portion 203 can be used for electrically connecting with an electrode assembly inside the housing. The cross-sectional dimension of the first electrical connection portion 202 is larger than that of the second electrical connection portion 203. That is to say, along the axial direction of the electrode terminal 200, the orthographic projection area of the first electrical connection portion 202 can cover the orthographic projection area of the second electrical connection portion 203. The fixing member 201 being connected to the second electrical connection portion 203 can be that the fixing member 201 is movably and detachably connected to the second electrical connection portion 203. In other embodiments, the fixing member 201 can also be fixedly connected to the second electrical connection portion 203.

[0040] In some embodiments, the first electrical connection portion 202 can be a cylinder, the second electrical connection portion 203 can be a cylinder, and they are connected to the first electrical connection portion 202.

[0041] The sealing member 205 can be a sealing ring with a certain thickness. The compression resilience of the sealing member 205 can be understood as the resilience force in the direction opposite to the compression direction when the sealing member 205 is compressed along the axial direction of the sealing member 205. Since the sealing member 205 is pressed between the first electrical connection portion 202 and the first surface 101, this compression resilience can be a force in the direction away from the first surface 101.

[0042] The fixing member 201 can be made of a metal material. The shape of the fixing member 201 can be strip-shaped. In other embodiments, the fixing member 201 can also be of other shapes. At least part of the fixing member 201 can abut against the first insulating member 40. It can be understood that, in the direction perpendicular to the surface of the first insulating member 40 facing away from the second surface 102, at least part of the fixing member 201 abuts against the first insulating member 40.

[0043] In the embodiment of the present application, the seal 205 is pressed between the first electrical connection portion 202 of the electrode terminal 200 and the first surface 101. Thus, when the first electrical connection portion 202 applies a pressure to the seal 205 towards the first surface 101, the seal 205 is compressed to generate a resilience force in the direction opposite to the compression direction. The compression resilience force of the seal 205 applies a force to the electrode terminal 200 in the direction away from the cover body 10, causing the electrode terminal 200 to have a tendency to move away from the cover body direction. The fixing member 201 is connected to the second electrical connection portion 203 of the electrode terminal 200, and at least a part of the fixing member 201 can abut against the first insulating member 40 under the action of the compression resilience force of the seal 205, applying a force opposite to the compression resilience force of the seal 205 to the electrode terminal 200, which can limit the movement of the electrode terminal 200 away from the cover body 10. The compression resilience force of the seal 205 and the reaction force of the fixing member 201 form a balance, so that the electrode terminal 200 is pressed and fixed on the cover assembly under the combined action of the fixing member 201 and the seal 205, eliminating the riveting or welding process, simplifying the processing process of the cover assembly, and reducing the processing cost of the cover assembly.

[0044] In some embodiments, as Figure 2 and Figure 3 shown, the first insulating member 40 has a third surface 103 facing away from the cover body 10. The length direction of the fixing member 201 is parallel to the third surface 103. The two ends of the length direction of the fixing member 201 protrude from the second electrical connection portion 203. Under the action of the compression resilience force of the seal 205, the part of the fixing member 201 protruding from the second electrical connection portion 203 abuts against the third surface 103 of the first insulating member 40.

[0045] It should be noted that the third surface 103 of the first insulating member 40 can be the side surface of the first insulating member 40 facing the inside of the housing. The length direction of the fixing member 201 being parallel to the third surface 103 can be understood as the fixing member 201 extending in a plane parallel to the third surface 103. Preferably, the surfaces of the fixing member 201 in its thickness direction are all parallel to the third surface 103. The two ends of the length direction of the fixing member 201 protruding from the second electrical connection portion 203 can be understood as the two ends of the length direction of the fixing member 201 extending beyond the second electrical connection portion 203. The part of the fixing member 201 protruding from the second electrical connection portion 203 can be understood as the part of the length direction of the fixing member 201 exceeding the second electrical connection portion 203.

[0046] In the embodiment of the present application, the length direction of the fixing member 201 is parallel to the third surface 103 and is connected to the second electrical connection portion 203. The two ends of the fixing member 201 in the length direction protrude from the second electrical connection portion 203. The portions of the fixing member 201 protruding from the second electrical connection portion 203 can abut against the third surface 103 of the first insulating member 40 under the action of the compression resilience of the sealing member 205, which can increase the contact area between the fixing member 201 and the third surface 103, making the fixing of the fixing member 201 to the electrode terminal 200 more stable, giving a force opposite to the compression resilience of the sealing member 205 to the electrode terminal 200, restricting the movement of the electrode terminal 200 away from the cover plate assembly, and the compression resilience of the sealing member 205 and the reaction force of the fixing member 201 form a balance. Thus, under the combined action of the fixing member 201 and the sealing member 205, the electrode terminal 200 is tightly fixed on the cover plate assembly, eliminating the riveting or welding process, simplifying the processing process of the cover plate assembly, and reducing the processing cost of the cover plate assembly.

[0047] In some embodiments, please refer to Figure 3 , to realize the connection between the second electrical connection portion 203 and the fixing member 201, the second electrical connection portion 203 is provided with a through hole 204 for accommodating the fixing member 201. The central axis of the through hole 204 extends along a direction parallel to the third surface 103. The fixing member 201 passes through the through hole 204 and the two ends of the fixing member 201 protrude from the through hole 204.

[0048] Along the direction perpendicular to the third surface 103, the through hole 204 has a first side surface 2041 and a second side surface 2042, where the second side surface 2042 is closer to the first electrical connection portion 202 than the first side surface 2041. The fixing member 201 passes through the through hole 204 and the two ends of the fixing member 201 protrude from the through hole 204; under the action of the compression resilience of the sealing member 205, the portion of the fixing member 201 protruding from the through hole 204 abuts against the third surface 103 of the first insulating member 40, and the portion of the fixing member 201 located inside the through hole 204 abuts against the first side surface 2041.

[0049] The through hole 204 is a hole penetrating the second electrical connection portion 203. The central axis of the through hole 204 can extend in any direction parallel to the third surface 103. The fixing member 201 passing through the through hole 204 can be understood as the fixing member 201 being movably and detachably passed through the through hole 204. The first side surface 2041 can be the bottom surface of the through hole 204, and the second side surface 2042 can be the top surface of the through hole 204.

[0050] In the embodiment of the present application, when assembling the electrode terminal 200, the cover body 10 and the first insulating member 40, the fixing member 201 can be directly inserted into the through hole 204. Under the action of the compression resilience of the sealing member 205, when the part of the fixing member 201 protruding from the through hole 204 abuts against the third surface 103 of the first insulating member 40, the part of the fixing member 201 located in the through hole 204 abuts against the first side surface 2041. Apply a force opposite to the compression resilience of the electrode terminal 200 and the sealing member 205, so that the electrode terminal 200 is pressed and fixed on the cover plate under the combined action of the fixing member 201 and the sealing member 205, simplifying the assembly process and reducing the processing cost.

[0051] Preferably, the central axis of the through hole 204 can extend along a direction parallel to the short side of the cover body 10, as Figure 2 shown. In some other embodiments, the central axis of the through hole 204 can also form an angle with the short side of the cover body 10.

[0052] In some embodiments, on a plane parallel to the third surface 103 and along a direction perpendicular to the central axis of the through hole 204, the width of the fixing member 201 is smaller than the width of the through hole 204. Along the central axis direction of the through hole 204, the length of the fixing member 201 is greater than the length of the through hole 204.

[0053] In the embodiment of the present application, through the above settings, it is convenient for the fixing member 201 to be movably inserted into the through hole 204, and both ends of the fixing member 201 in the length direction can protrude from both ends of the through hole 204, so that the fixing member 201 can abut against the third surface 103 to apply a force opposite to the compression elastic force of the electrode terminal 200 and the sealing member 205.

[0054] In some embodiments, as Figure 7 shown, the length of the two ends of the fixing member 201 in the length direction protruding from the through hole 204 is h, satisfying: 0.5 mm ≤ h ≤ 10 mm. In some embodiments, h can be 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or 10 mm.

[0055] In the embodiments of the present application, by setting the lengths of the two ends of the fixing member 201 in the length direction to protrude from the through hole 204 within the above range, the two ends of the fixing member 201 protruding from the through hole 204 can abut against the third surface 103 of the first insulating member 40 under the action of the compression resilience of the sealing member 205, forming a stable fixation of the electrode terminal 200. When the lengths of the two ends of the fixing member 201 in the length direction protruding from the through hole 204 are less than 0.5 mm, the protruding length of the fixing member 201 is too short and it is not easy to abut against the first insulating member 40, resulting in unstable fixation of the electrode terminal 200. When the lengths of the two ends of the fixing member 201 in the length direction protruding from the through hole 204 are greater than 10 mm, the protruding length of the fixing member 201 is too long, increasing both the cost and the weight.

[0056] In some embodiments, as Figure 6 shown, the compression ratio of the sealing member 205 satisfies: where f is the thickness of the sealing member 205 along its axial direction before being compressed, and g is the thickness of the sealing member 205 along its axial direction after being compressed. In some embodiments, the compression ratio of the sealing member 205 can be 0.25, 0.3, 0.35, 0.4, 0.45 or 0.5.

[0057] In the embodiments of the present application, setting the compression ratio of the sealing member 205 within the above range can enable the sealing member 205 to maintain good sealing performance, and at the same time, the sealing member 205 is not easily degraded after long-term use. When the compression ratio of the sealing member 205 is less than 0.25, it is likely to cause poor sealing. When the compression ratio of the sealing member 205 is greater than 0.5, the sealing member is easily degraded and its aging resistance performance is poor. The test results of the compression ratio and its performance of the sealing member 205 are shown in Table 1.

[0058] Table 1 Test results of the compression ratio and its performance of the sealing member

[0059]

[0060] It can be seen from the test results in Table 1 that when the compression ratio of the sealing member 205 is less than 0.25, for example, 0.2, the sealing performance of the sealing member 205 is poor. When the compression ratio of the sealing member 205 is greater than 0.5, for example, 0.55, the sealing member 205 has degraded and its aging resistance performance is poor.

[0061] In some embodiments, please refer to Figures 3 to 6 , along the axial direction of the mounting hole 100, the through hole 204 has a first side surface 2041 and a second side surface 2042, and the distance a between the first side surface 2041 of the through hole 204 and the second electrical connection surface 2031 of the second electrical connection portion 203 satisfies: 1 mm ≤ a ≤ 3 mm. a can be 1 mm, 1.5 mm, 2 mm, 2.5 mm or 3 mm.

[0062] The first side 2041 of the through hole 204 can be the side of the through hole 204 facing the electrode assembly along the axial direction of the mounting hole 100. The second electrical connection surface 2031 of the second electrical connection portion 203 can be the surface where the second electrical connection portion 203 is electrically connected to the electrode assembly.

[0063] In the embodiments of the present application, through the above settings, when ensuring a soft connection between the second electrical connection portion 203 and the electrode assembly, the penetration depth is not easily penetrated through the through hole 204, so that the fixing member 201 is not easily deformed, and at the same time, it is not easy to make the height of the electrode terminal 200 too large and occupy too much space. When the distance a between the first side 2041 of the through hole 204 and the second electrical connection surface 2031 of the second electrical connection portion 203 is less than 1 mm, it is easy to cause the penetration depth to easily penetrate through the through hole 204 during the soldering soft connection between the second electrical connection portion 203 and the electrode assembly, resulting in deformation of the fixing member 201. When the distance a between the first side 2041 of the through hole 204 and the second electrical connection surface 2031 of the second electrical connection portion 203 is greater than 3 mm, it will cause the height of the electrode terminal 200 to be too high, which is not conducive to capacity improvement. At the same time, the material consumption of the electrode terminal 200 is large and the cost is high.

[0064] The test results of the distance a between the first side 2041 of the through hole 204 and the second electrical connection surface 2031 of the second electrical connection portion 203 are shown in Table 2.

[0065] Table 2 Test results of the distance a

[0066]

[0067] It can be seen from the test results in Table 2 that when the distance a between the first side 2041 of the through hole 204 and the second electrical connection surface 2031 of the second electrical connection portion 203 is less than 1 mm, the distance a is 0.5 mm. During the soldering soft connection between the second electrical connection portion 203 and the electrode assembly, the penetration depth is easily penetrated through the through hole 204, resulting in deformation of the fixing member 201. When the distance a between the first side 2041 of the through hole 204 and the second electrical connection surface 2031 of the second electrical connection portion 203 is greater than 3 mm, the distance a is 3.5 mm, which will cause the height of the electrode terminal 200 to be too high, not conducive to capacity improvement. At the same time, the material consumption of the electrode terminal 200 is large and the cost is high.

[0068] In some embodiments, please refer to Figure 6 , the distance between the second side 2042 of the through hole 204 and the first electrical connection surface 2021 of the first electrical connection portion 202 is b, satisfying: 1.5 mm ≤ b ≤ 3 mm. b can take 1.5 mm, 2 mm, 2.5 mm or 3 mm.

[0069] The second side surface 2042 of the through hole 204 can be the side surface of the through hole 204 facing away from the electrode assembly towards the outside of the housing along the axial direction of the mounting hole 100, and the first electrical connection surface 2021 of the first electrical connection portion 202 can be the surface of the first electrical connection portion 202 located outside the housing and connected to the external adapter along the axial direction of the mounting hole 100.

[0070] In the embodiment of the present application, through the above settings, it is ensured that when the first electrical connection surface 2021 of the first electrical connection portion 202 is welded to the adapter, the welding penetration depth will not penetrate the through hole 204, causing deformation of the fixing member 201, and the height of the electrode terminal 200 will not be too high. When the distance b between the second side surface 2042 of the through hole 204 and the first electrical connection surface 2021 of the first electrical connection portion 202 is less than 1.5 mm, the welding penetration depth of the first electrical connection surface 2021 of the first electrical connection portion 202 of the electrode terminal 200 and the adapter is likely to penetrate the through hole 204, causing deformation of the fixing member 201. When the distance b between the second side surface 2042 of the through hole 204 and the first electrical connection surface 2021 of the first electrical connection portion 202 is greater than 3 mm, the height of the electrode terminal 200 is too high, which is not conducive to capacity improvement. At the same time, the material consumption of the electrode terminal 200 is large and the cost is high. The test results of the distance b between the second side surface 2042 of the through hole 204 and the first electrical connection surface 2021 of the first electrical connection portion 202 are shown in Table 3.

[0071] Table 3 Test results of the distance b

[0072]

[0073]

[0074] It can be seen from the test results in Table 3 that when the distance b between the second side surface 2042 of the through hole 204 and the first electrical connection surface 2021 of the first electrical connection portion 202 is less than 1.5 mm, and the distance b is 1 mm, the welding penetration depth of the first electrical connection surface 2021 of the first electrical connection portion 202 of the electrode terminal 200 and the adapter is likely to penetrate the through hole 204, causing deformation of the fixing member 201. When the distance b between the second side surface 2042 of the through hole 204 and the first electrical connection surface 2021 of the first electrical connection portion 202 is greater than 3 mm, and the distance b is 3.5 mm, the height of the electrode terminal 200 is too high, which is not conducive to capacity improvement. At the same time, the material consumption of the electrode terminal 200 is large and the cost is high.

[0075] The electrode terminal 200 in the cover plate assembly of the present application can be directly connected to the electrode assembly through the second electrical connection surface 2031 of the second electrical connection part 203, and directly connected to the adapter plate through the first electrical connection surface 2021 of the first electrical connection part 202. The adapter block structure connected to the external adapter plate provided in the first electrical connection part 202 is cancelled, enabling overcurrent to pass through the electrode terminal 200 itself inside and outside the battery cell, without the need for other components for connection. This can make the battery cell have a smaller resistance, improve the cycling performance of the battery cell, and extend the service life of the battery cell.

[0076] In some embodiments, the maximum tensile resistance of the fixing member 201 is not less than the compression resilience of the sealing member 205.

[0077] The material of the fixing member 201 can be metal, such as aluminum. The maximum tensile resistance of the fixing member 201 can be understood as the maximum tensile resistance on the minimum cross-sectional area perpendicular to the stress direction of the fixing member 201, which is the product of the tensile strength and the cross-sectional area of the fixing member 201. As Figure 6 shown, the fixing member 201 can be a strip-shaped structure, the width of the fixing member 201 is c, the thickness of the fixing member 201 is d, and the tensile strength of the fixing member 201 is σ. For example, the tensile strength of aluminum is 95 Mpa. Then the maximum tensile resistance of the fixing member 201 is σ×c×d.

[0078] The compression resilience of the sealing member 205 can be calculated by the following formula: where S refers to the contact area between the surface of the sealing member 205 parallel to the first surface 101 and the first electrical connection part 202. As Figure 8 shown, the contact area S between the surface of the sealing member 205 and the first electrical connection part 202 can be calculated by the following formula: S = e×sealing perimeter, where e is the contact width, and the sealing perimeter can be the perimeter of the center line of the sealing member 205, such as a sealing ring. In the above formula for the compression resilience of the sealing member 205: represents the rebound stress per unit area of the sealing member 205 at a certain compression rate, with the unit of MPa / mm 2 , which is based on the stress-strain values of the sealing member 205 at different compression rates ( such as 20%, 25%, 30%, 35%, 40%), and then the stress curve equation of the sealing member 205 between the compression rates of 25% - 50% is deduced by fitting. The maximum tensile resistance of the fixing member 201 is not less than the compression resilience of the sealing member 205, that is

[0079]

[0080] In the embodiments of the present application, by making the maximum tensile strength of the fixing member 201 not less than the compression resilience of the sealing member 205, the fixing member 201 has sufficient strength to avoid deformation due to insufficient strength of the fixing member 201, thereby affecting the stability of the electrode terminal 200 and the service life of the battery cell.

[0081] Taking the fixing member 201 as aluminum as an example, the test results of the compression resilience of the sealing member 205 and the maximum tensile strength of the fixing member 201 are shown in Table 4.

[0082] Table 4 Test results of the compression resilience of the sealing member and the maximum tensile strength of the fixing member

[0083]

[0084] It can be seen from the test results in Table 4 that when the maximum tensile strength of the fixing member 201 is greater than the compression resilience of the sealing member 205, after the cover body 10, the first insulating member 40 and the terminal assembly 20 are assembled, the overall structure is normal and the fixing member 201 will not deform. When the maximum tensile strength of the fixing member 201 is less than the compression resilience of the sealing member 205, the strength of the fixing member 201 is insufficient and the fixing member 201 is prone to deformation.

[0085] In some embodiments, the cover assembly further includes a second insulating member 30. The second insulating member 30 is sleeved on the outer side of the sealing member 205 and is used to insulate the first electrical connection portion 202 and the cover body 10. The second insulating member 30 may be a ring structure made of plastic material.

[0086] When assembling the cover assembly of the present application, the following can be referred to:

[0087] The sealing member 205 is sleeved on the electrode terminal 200, and the second insulating member 30, the cover body 10, the first insulating member 40 and the fixing member 201 are assembled in sequence from bottom to top. Among them, before the fixing member 201 and the through hole 204 are inserted, the entire cover assembly is fixed, the sealing member 205 is in a compressed state, and the part of the through hole 204 where the first side surface 2041 exceeds the third surface 103 and the through hole 204 is exposed allows the fixing member 201 to be inserted. At this time, the fixing member 201 is inserted into the through hole 204 from the side, and then the pressed cover assembly is released. Under the action of the compression resilience of the sealing member 205, the upper surface of the fixing member 201 abuts against the third surface 103 of the first insulating member 40, and the lower surface of the fixing member 201 abuts against the first side surface 2041 of the through hole 204. At this time, the cover body 10 and the electrode terminal 200 are completely fixed by the fixing member 201.

[0088] On the other hand, the present application also provides a battery, including at least one battery cell. The battery cell includes: a housing, an electrode assembly, and the cover assembly described in any one of the foregoing. The housing has an opening, and the cover assembly is disposed at the opening of the housing, and the electrode assembly is accommodated in the housing.

[0089] On the other hand, the present application also provides an electrical device including the battery described above. The electrical device can be used as a power source of the electrical device or as an energy storage unit of the electrical device. The electrical device can include mobile devices (such as mobile phones, laptops, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships, satellites, energy storage systems, etc., but is not limited thereto.

[0090] The foregoing are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A cover plate assembly, characterized in that, Comprising: A cover body having a first surface and a second surface disposed opposite to each other and a mounting hole penetrating through the first surface and the second surface; A first insulating member disposed on one side of the cover body having the second surface; A terminal assembly including an electrode terminal, a seal, and a fixing member. Wherein, the electrode terminal includes a first electrical connection portion and a second electrical connection portion. The first electrical connection portion is disposed on the first surface and covers the mounting hole. The seal is pressed between the first electrical connection portion and the first surface. The second electrical connection portion passes through the seal and is disposed in the mounting hole. The fixing member is connected to the second electrical connection portion. Under the action of the compression resilience of the seal, at least a part of the fixing member abuts against the first insulating member.

2. The cover plate assembly according to claim 1, wherein, The first insulating member has a third surface facing away from the cover body. The fixing member extends in a direction parallel to the third surface and is connected to the second electrical connection portion. The two ends of the fixing member in the length direction protrude from the second electrical connection portion. Under the action of the compression resilience of the seal, the part of the fixing member protruding from the second electrical connection portion abuts against the third surface of the first insulating member.

3. The cover plate assembly according to claim 2, characterized in that, The second electrical connection portion is provided with a through hole for accommodating the fixing member. The central axis of the through hole extends in a direction parallel to the third surface. Along a direction perpendicular to the third surface, the through hole has a first side surface and a second side surface. Wherein the second side surface is closer to the first electrical connection portion than the first side surface. The fixing member passes through the through hole and makes the two ends of the fixing member protrude from the through hole; Under the action of the compression resilience of the seal, the part of the fixing member protruding from the through hole abuts against the third surface of the first insulating member, and the part of the fixing member located in the through hole abuts against the first side surface.

4. The cover plate assembly according to claim 3, characterized in that, On a plane parallel to the third surface and along a direction perpendicular to the central axis of the through hole, the width of the fixing member is smaller than the width of the through hole. Along the central axis direction of the through hole, the length of the fixing member is greater than the length of the through hole. The length of the two ends of the fixing member in the length direction protruding from the through hole is h, satisfying: 0.5 mm ≤ h ≤ 10 mm.

5. The cover plate assembly according to claim 1, wherein The compression ratio of the seal meets the following condition: where f is the thickness of the seal along its axis before compression, and g is the thickness of the seal along its axis after compression.

6. The cover plate assembly according to claim 3, wherein Along the axial direction of the mounting hole, the distance between the first side surface of the through hole and the second electrical connection surface of the second electrical connection portion is a, satisfying: 1 mm ≤ a ≤ 3 mm, and / or, The distance between the second side surface of the through hole and the first electrical connection surface of the first electrical connection portion is b, satisfying: 1.5 mm ≤ b ≤ 3 mm.

7. The cover plate assembly according to claim 1, characterized in that, The maximum tensile strength of the fixing member is not less than the compression resilience of the seal.

8. The cover plate assembly according to claim 1, wherein, Further comprising: A second insulating member sleeved on the outside of the seal.

9. A battery, characterized in that, Including at least one battery cell, and the battery cell includes: A housing having an opening; The cover assembly according to any one of claims 1 to 8, covering the opening of the housing; An electrode assembly accommodated in the housing.

10. An electrical device, characterized in that, Including the battery according to claim 9.

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