Cover plate assembly, battery cell and electric device

Abstract

The application provides a cover plate assembly, a battery monomer and an electric device, relates to the technical field of batteries, and the cover plate assembly comprises a cover plate body and an explosion-proof valve. The explosion-proof valve is arranged on the cover plate body and is in an integral forming structure with the cover plate body. The explosion-proof valve comprises an opening part and a buffer part. The buffer part is arranged around the periphery of the opening part. The opening part is provided with a burst section. The buffer part comprises at least a first buffer section and a second buffer section. The first buffer section is connected with the cover plate body. The second buffer section is connected with the opening part. The second buffer section has a first wall surface. The opening part has a first opening surface connected with the first wall surface. The included angle between the first wall surface and the first opening surface is a, and 90°≤a≤180° is satisfied. In this way, the stability and forming yield of the explosion-proof valve are improved.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a cover plate assembly, a battery cell, and an electrical device. Background Technology

[0002] In related technologies, explosion-proof valves are typically fixed to the battery cover by welding. However, the heat generated during the welding process often causes slight deformation of the explosion-proof valve, resulting in a reduction in the thickness of the grooves on the valve. This change directly affects the opening pressure of the explosion-proof valve. Secondly, the heat generated during the welding of the battery casing and cover can also cause cracking of the explosion-proof valve, ultimately leading to complete malfunction. These problems not only significantly reduce the yield rate of battery production but also substantially increase production costs. Summary of the Invention

[0003] The purpose of this application is to provide a cover plate assembly, a battery cell, and an electrical device to solve the problem of poor stability of the explosion-proof valve in the battery cell in the prior art.

[0004] To achieve the above objectives, the technical solution adopted in this application is as follows: In a first aspect, this application provides a cover plate assembly, including: a cover plate body and an explosion-proof valve. The explosion-proof valve is disposed on the cover plate body and is integrally formed with the cover plate body. The explosion-proof valve includes an opening part and a buffer part. The buffer part is arranged circumferentially around the opening part. The opening part is provided with a bursting section. The buffer part includes at least a first buffer section and a second buffer section. The first buffer section is connected to the cover plate body, and the second buffer section is connected to the opening part. The second buffer section has a first wall surface. The opening part has a first opening surface connected to the first wall surface. The included angle between the first wall surface and the first opening surface is α, which satisfies: 90°≤α≤180°.

[0005] In one or more embodiments of this application, it further includes: a pole post disposed on a cover plate body, the cover plate body including a first surface and a second surface, the first surface and the second surface being disposed opposite to each other along the thickness direction of the cover plate body, at least a portion of the pole post protruding from the first surface and forming a first electrical connection surface, the distance between the first electrical connection surface and the first surface along the thickness direction of the cover plate body being A2, the thickness of the cover plate body being A1, and the distance between the end of the buffer portion away from the cover plate body and the first surface being A, satisfying: -0.5×A1≤A≤A2.

[0006] In one or more embodiments of this application, on a plane perpendicular to the thickness direction of the cover plate body, the distance T between the orthographic projection of the explosive section and the orthographic projection of the second buffer section of the buffer part satisfies: 0.2mm ≤ T ≤ 3mm; and / or, On a plane perpendicular to the thickness direction of the cover plate body, the distance between the orthographic projection of the first buffer segment of the buffer part and the orthographic projection of the cover plate body is C, which satisfies C≥1mm.

[0007] In one or more embodiments of this application, the maximum thickness of the opening portion along the thickness direction of the cover plate body is D, satisfying 0.15mm ≤ D ≤ 0.4mm; and / or, The thickness of the second buffer section 211 is T1, which satisfies: D≤T1≤2D.

[0008] In one or more embodiments of this application, the buffer section further includes a bending section, a third buffer section, and a fourth buffer section; wherein the first buffer section, the third buffer section, the fourth buffer section, the bending section, and the second buffer section are connected sequentially from the cover plate body to the opening section.

[0009] In one or more embodiments of this application, the first buffer section extends along the direction perpendicular to the thickness of the cover plate body, one end of the third buffer section is connected to the first buffer section, the other end of the third buffer section extends along the thickness of the cover plate body, one end of the fourth buffer section is connected to the third buffer section, the other end of the fourth buffer section is inclined in a direction away from the opening, one end of the second buffer section is connected to the fourth buffer section through a bending section, and the other end of the second buffer section is inclined in a direction towards the opening.

[0010] In one or more embodiments of this application, the inner fillet radius of the bent segment is R, satisfying: 0.5×T1≤R≤3×T1; and / or, The thickness of the fourth buffer segment is T2, satisfying: T1≤T2≤3×T1; and / or, The thickness of the third buffer section is T3, satisfying: T1≤T3≤2×T2; and / or, The thickness of the first buffer section is T4, and the thickness of the cover plate body is A1, satisfying: T1≤T4≤0.6×A1.

[0011] Secondly, this application provides a battery cell, including: a housing and the cover assembly described in the first aspect, the housing having an opening; the cover assembly being connected to the opening of the housing.

[0012] Thirdly, this application provides an electrical device, comprising: an electrical main body and at least one battery cell as described in the second aspect, wherein the battery cell is electrically connected to the electrical main body.

[0013] Based on the above technical solutions, the cover plate assembly, battery cell, and power supply device of this application have at least the following beneficial technical effects: The cover plate assembly of this application eliminates the need for welding the explosion-proof valve and the cover plate body by making them an integrally formed structure. This eliminates stress concentration and minor deformation caused by welding between the explosion-proof valve and the cover plate body, thus helping to maintain the consistency of the wall thickness of the bursting section and ensuring that the opening pressure of the explosion-proof valve is controlled within the design threshold. This avoids the risk of deformation and functional failure of the explosion-proof valve due to welding between the valve and the cover plate. Simultaneously, a buffer section is provided between the opening section and the cover plate body. This buffer section increases the heat conduction path length between the opening section and the cover plate body, reducing the impact on the opening section, especially the bursting section, thereby improving production yield. Furthermore, the included angle between the first wall surface of the second buffer section of the buffer section and the first opening surface of the opening section is set to satisfy 90°≤a≤180°. This ensures that the explosion-proof valve is easy to form and also avoids interference between the edge of the buffer section and the cover plate body. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of the electrical device provided in the embodiments of this application.

[0016] Figure 2 This is a cross-sectional structural diagram of the battery pack in the electrical device provided in the embodiments of this application.

[0017] Figure 3 This is a schematic diagram of the structure of a single battery cell in a battery pack provided in an embodiment of this application.

[0018] Figure 4 This is a perspective view of the cover plate assembly provided in the embodiments of this application.

[0019] Figure 5 yes Figure 4 A magnified structural diagram at point B in the middle.

[0020] Figure 6 This is a partial cross-sectional view of the cover plate assembly provided in the embodiments of this application.

[0021] Figure 7 yes Figure 6 A magnified structural diagram at point C.

[0022] Figure 8 yes Figure 6 A partial enlarged view of the cover plate assembly provided in the embodiments of this application.

[0023] Figure 9 This is a cross-sectional view along the width direction of the cover plate assembly provided in the embodiments of this application.

[0024] Figure 10 This is a top view of a cover plate assembly provided in one embodiment of this application.

[0025] Figure 11 This is a top view of a cover plate assembly provided in another embodiment of this application.

[0026] In the diagram: 100-Electrical device; 110-Electrical main body; 111-Battery compartment; 120-Battery pack; 121-Battery cell; 122-Box; 1000-Cover assembly; 1001-Shell; 1-Cover body; 10-First surface; 11-Second surface; 2-Explosion-proof valve; 20-Opening section; 21-Buffer section; 22-Reinforcing section; 23-Through hole; 200-Explosion section; 201-First opening surface; 210-First buffer section; 211-Second buffer section; 212-Third buffer section; 213-Fourth buffer section; 214-Bending section; 215-Cavity; 2111-First wall surface; 3-Terminal post; 30-First electrical connection surface; 31-Second electrical connection surface. Detailed Implementation

[0027] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0028] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0029] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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. Therefore, they should not be construed as limitations on this application.

[0030] 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 one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0031] In related technologies, explosion-proof valves are typically fixed to the battery cover by welding. However, the heat generated during the welding process often causes slight deformation of the explosion-proof valve, resulting in a reduction in the thickness of the grooves on the valve. This change directly affects the opening pressure of the explosion-proof valve. Secondly, the large amount of heat released during the welding of the battery casing and cover can also cause the explosion-proof valve to crack, ultimately leading to complete malfunction. These problems not only significantly reduce the yield rate of battery production but also substantially increase production costs.

[0032] To address the aforementioned issues, this application provides a cover plate assembly, a battery cell, and an electrical device to resolve the problem of poor stability of explosion-proof valves in the prior art.

[0033] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0034] Please see Figure 1 , Figure 1 This is a schematic diagram of an electrical device 100 provided in an embodiment of this application. Figure 1 In the illustrated embodiments, an electric vehicle is used as an example for illustrative purposes, and this should not be construed as a specific limitation of this application. In other embodiments, the electrical device may also be a mobile phone, a laptop computer, a mobile charging station, or other similar devices.

[0035] Please see Figure 1 The power-consuming device 100 includes a power-consuming body 110 and a battery pack 120. The battery pack 120 is fixed to the power-consuming body 110 and electrically connected to the power-consuming components of the power-consuming body 110 to supply power to the power-consuming components of the power-consuming body 110. Specifically, the power-consuming body 110 may have a battery compartment 111, and the battery pack 120 is fixed inside the battery compartment 111. In an exemplary embodiment, the power-consuming components may be a drive motor, and various sensors (wheel speed sensors), etc.

[0036] Please continue reading. Figure 2The battery pack 120 may include a housing 122 and at least one battery cell 121, wherein the battery cell 121 is electrically connected to the aforementioned power-consuming body 110. The battery cell 121 is fixed inside the housing 122, which protects the battery cell 121 from external forces causing vibration and impact that could damage it. The housing 122 may be a metal housing or a plastic housing. The battery cell 121 is the most basic electrochemical unit, capable of storing and releasing electrical energy. The battery cell 121 may be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and this application embodiment does not limit the types. Figure 2 In the battery pack 120 shown, there are multiple battery cells 121. These multiple battery cells 121 can be electrically connected in series, in parallel, or in a mixed configuration. A mixed configuration means that the multiple battery cells 121 are connected in both series and parallel relationships, which can be specifically designed according to the power consumption requirements of the power-consuming device 100. In some other embodiments, the battery pack 120 may contain only one battery cell 121.

[0037] Please continue reading. Figure 3 The battery cell 121 may include a housing 1001, a cell, and a cover assembly 1000. The housing 1001 has a receiving cavity (not shown) and an opening (not shown) communicating with the receiving cavity. The receiving cavity is used to receive the cell and electrolyte. The opening is used to place the cell into the receiving cavity through the opening during battery cell assembly. The cover assembly 1000 is connected to the opening to close it, thereby forming a sealed battery cell structure. The cell has tabs that are electrically connected to the cover assembly 1000.

[0038] The housing 1001 can be a rigid component, and it can be generally rectangular in shape so that the battery cell 121 is also generally rectangular. The housing 1001 can be a metal housing. In some embodiments, the housing 1001 can be an aluminum alloy housing to make it lighter, which is beneficial for the lightweight of the battery cell and thus for the overall lightweight of the electrical device. In other embodiments, the housing 1001 can also be a stainless steel housing to give it higher strength, which in turn gives the battery cell 121 better overall strength and stronger resistance to puncture and vibration damage. In still other embodiments, the housing 1001 can also be a flexible component.

[0039] Please continue to refer to Figure 4The cover assembly 1000 of this application includes a cover body 1 and an explosion-proof valve 2. The shape of the cover body 1 can be adapted to the shape of the opening of the housing 1001. The cover body 1 is connected to the housing 1001 and seals the opening to protect the battery cell and prevent electrolyte leakage. Figure 4 In the illustrated embodiment, the cover plate body 1 is a rectangular flat plate. In other embodiments, the cover plate body 1 may also be circular, triangular, or other shapes.

[0040] The cover body 1 can be a metal structural component, connected to the housing 1001 by welding, bonding, or snap-fitting. In some embodiments, the cover body 1 can be an aluminum alloy structural component, which is beneficial for the lightweighting of the battery cell 121 and the electrical device 100. In other embodiments, the cover body 1 can be a stainless steel component, so that the cover body 1 has high strength, thereby giving the battery cell 121 high strength.

[0041] The explosion-proof valve 2 is mounted on the cover plate body 1 and is integrally formed with the cover plate body 1. Compared with the existing technology that uses welding to connect the explosion-proof valve 2 and the cover plate body 1, this embodiment fundamentally eliminates the welding process required for the explosion-proof valve 2 and the cover plate body 1. This eliminates stress concentration and minor deformation caused by welding of the explosion-proof valve 2 and the cover plate body 1, maintains the consistency of the wall thickness of the rupture section 200, and ensures that the opening pressure of the explosion-proof valve 2 is controlled within the design threshold, avoiding the risk of failure caused by welding deformation of the explosion-proof valve 2 and the cover plate body 1.

[0042] It should be noted that the integrated molding structure refers to a continuous and seamless integral structure formed by the explosion-proof valve 2 and the cover plate body 1 through the same manufacturing process, rather than a component that is combined through subsequent connection processes (such as welding or riveting).

[0043] Please refer to Figure 4 or Figure 5The explosion-proof valve 2 includes an opening portion 20 and a buffer portion 21. The buffer portion 21 is arranged circumferentially around the opening portion 20, and the end of the buffer portion 21 away from the opening portion 20 is connected to the cover plate body 1. Thus, the buffer portion 21 serves as an intermediate transition structure connecting the opening portion 20 and the cover plate body 1, thereby extending the heat conduction path between them. Specifically, when the cover plate body 1 is welded and packaged with the battery casing 1001, the high temperature generated during welding needs to travel a longer path to reach the opening portion 20. The buffer portion 21 effectively blocks and disperses the welding heat and stress, reducing the impact on the opening portion 20, especially the burst section 200, improving the stability and reliability of the explosion-proof valve 2, and significantly increasing production yield. It should be noted that in the cover plate assembly of this application embodiment, the buffer part 21, the opening part 20 and the cover plate body 1 are all integrally formed structures. The materials of the buffer part 21, the opening part 20 and the cover plate body 1 are continuous and there is no welding interface, which not only ensures the sealing performance, but also improves the structural strength of the explosion-proof valve 2.

[0044] Please refer to Figure 5 The opening portion 20 is provided with a burst section 200. The burst section 200 can be a groove structure that reduces the local structural strength of the opening portion 20. For example, the burst section 200 can be a groove formed by laser engraving or mechanical scribing. Along the thickness direction of the cover plate body 1, the cross-section of the groove can be V-shaped. The depth, length, and shape of the burst section 200 together determine the opening pressure of the explosion-proof valve 2. Specifically, when the internal pressure of the battery cell exceeds the preset valve opening pressure, the burst section 200 can at least partially break, causing the opening portion 20 to rupture, thereby opening the explosion-proof valve 2 to provide an emergency pressure relief channel inside the battery cell.

[0045] Reference Figure 7 The buffer section 21 includes a first buffer segment 210, a second buffer segment 211, a bent segment 214, a third buffer segment 212, and a fourth buffer segment 213. The first buffer segment 210, the third buffer segment 212, the fourth buffer segment 213, the bent segment 214, and the second buffer segment 211 are sequentially connected from the cover plate body 1 to the opening portion 20. The buffer section 21 formed by the first buffer segment 210, the third buffer segment 212, the fourth buffer segment 213, the bent segment 214, and the second buffer segment 211, together with the opening portion 20, forms a cavity 215. The cavity 215 communicates with the interior of the housing 1001, so that when the pressure inside the housing 1001 increases, the pressure can be quickly applied to the explosion-proof valve 2 through the cavity 215. The first buffer segment 210, the third buffer segment 212, the fourth buffer segment 213, the bent segment 214, and the second buffer segment 211 are integrally formed structures.

[0046] In some embodiments, please refer to Figure 7The first buffer section 210 extends along a direction perpendicular to the thickness of the cover plate body 1. It can be understood that the extension direction of the first buffer section 210 refers to its width direction, meaning that both ends of the first buffer section 210 in its width direction are connected to the cover plate body 1 and the third buffer section 212, respectively. One end of the third buffer section 212 is connected to the first buffer section 210, and the other end of the third buffer section 212 extends along the thickness direction of the cover plate body 1. It can be understood that the extension direction of the third buffer section 212 refers to its width direction, meaning that both ends of the third buffer section 212 in its width direction are connected to the first buffer section 210 and the fourth buffer section 213, respectively. One end of the fourth buffer section 213 is connected to the third buffer section 212, and the other end of the fourth buffer section 213 is inclined away from the opening part 20. It can be understood that one end of the fourth buffer section 213 in its width direction is connected to the third buffer section 212, and the other end is inclined away from the central axis of the explosion-proof valve 2. One end of the second buffer section 211 is connected to the fourth buffer section 213 via the bent section 214, and the other end of the second buffer section 211 is inclined toward the opening part 20. It can be understood that one end of the second buffer section 211 in the width direction is connected to the fourth buffer section 213 via the bent section 214, and the other end is inclined toward the central axis of the explosion-proof valve 2 and connected to the opening part 20. Thus, within a limited height space, a curved buffer part 21 is formed, consisting of the first buffer section 210, the third buffer section 212, the fourth buffer section 213, the bent section 214, and the second buffer section 211. When the battery cell housing 1001 is welded to the cover plate body 1, heat will pass through the first buffer section 210, the third buffer section 212, the fourth buffer section 213, the bent section 214, and the second buffer section 211 to the opening part 20, thereby increasing the heat conduction path and ensuring the stability and reliability of the explosion-proof valve 2.

[0047] Reference Figure 6 and Figure 7The first buffer section 210 is connected to the cover body 1, and the second buffer section 211 is connected to the opening part 20. The first buffer section 210 has a first wall surface 2111, which can be the surface facing the outside of the battery cell along the thickness direction of the first buffer section 210. The opening part 20 has a first opening surface 201 connected to the first wall surface 2111, which can be the surface facing the outside of the battery cell. The included angle between the first wall surface 2111 and the first opening surface 201 is α, which satisfies: 90°≤α≤180°. For example, α can be 90°, 95°, 100°, 110°, 120°, 130°, 140°, 150°, 160°, 70°, 180°, etc., or any value between any two of the above values. Therefore, 'a' is limited to the range of 90° to 180° to ensure that the explosion-proof valve 2 is easily formed by the stamping process while preventing the outer periphery of the buffer section 21 from interfering with the cover plate body 1. When 'a' is less than 90°, the angle between the second buffer section 211 and the opening section 20 is too small, making it difficult to form from the perspective of the stamping process. When 'a' is greater than 180°, the edge of the buffer section 21 will bend downwards (i.e., bend towards the cover plate body 1), which can easily cause structural interference with the cover plate body 1.

[0048] In some embodiments, the following condition is satisfied: 120°≤a≤150°. For example, a can be 120°, 130°, 140° or 150°, or any value between any two of the above values. This setting can better realize the molding of the explosion-proof valve 2 and improve the space utilization rate.

[0049] In some embodiments, please refer to Figure 6 The cover plate assembly 1000 also includes a terminal post 3 for electrical connection with the electrode tab of the battery cell. The cover plate body 1 includes a first surface 10, a second surface 11, and a through hole. The first surface 10 and the second surface 11 are arranged opposite to each other along the thickness direction of the cover plate body 1, and the through hole penetrates the first surface 10 and the second surface 11 along its own axial direction. The terminal post 3 is disposed on the cover plate body 1 and installed in the through hole. The connection between the terminal post 3 and the cover plate body 1 can be fixed in the through hole by riveting or snap-fitting.

[0050] Please refer to Figure 6At least a portion of the electrode post 3 protrudes from the first surface 10, forming a first electrical connection surface 30. The first electrical connection surface 30 is located on the side of the first surface 10 opposite to the second surface 11, and is used for electrical connection with a busbar or external electrical component. The electrode post 3 also has a second electrical connection surface 31, which is arranged opposite to the first electrical connection surface 30 along the thickness direction of the cover plate body 1, and is used for connection with the tab of the battery cell. In some embodiments, to increase the contact area between the second electrical connection surface 31 and the tab, an adapter piece may be provided between the second electrical connection surface 31 and the tab.

[0051] In some embodiments, please refer to Figure 6 Along the thickness direction of the cover plate body 1, the distance between the first electrical connection surface 30 and the first surface 10 is A2. The thickness of the cover plate body 1 is A1, and the distance between the end of the buffer part 21 away from the cover plate body 1 and the first surface 10 is A. This satisfies: -0.5×A1≤A≤A2. Through the above settings, it can be ensured that the buffer part 21 of the explosion-proof valve 2 is in a suitable position in the height direction of the battery cell, which can both ensure that the explosion-proof valve 2 is easier to form and avoid reducing the overall space utilization rate inside the battery cell.

[0052] Specifically, when A is less than -0.5×A1, that is, the buffer part 21 of the explosion-proof valve 2 is recessed below the first surface 10 of the cover plate body 1, the material flow is difficult during the stamping process, making it difficult to form the explosion-proof valve 2. When A is greater than A2, that is, along the thickness direction of the cover plate body 1, the explosion-proof valve 2 is higher than the first electrical connection surface 30 of the pole post 3, which will occupy extra space inside the battery cell and reduce the space utilization rate inside the battery cell.

[0053] In some embodiments, please refer to Figure 7 On a plane perpendicular to the thickness direction of the cover plate body 1, the distance T between the orthographic projection of the bursting section 200 and the orthographic projection of the second buffer section 211 of the buffer part 21 satisfies 0.2mm ≤ T ≤ 3mm. For example, T can take values ​​of 0.2mm, 0.5mm, 0.8mm, 1.0mm, 1.2mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.8mm, 3mm, etc., or any value between any two of the above values. This ensures that the opening part 20 has a sufficient opening area while preventing the bursting section 200 from being too close to the cover plate body 1, which would make the bursting section 200 susceptible to the effects of welding heat and thus affect the product yield.

[0054] Specifically, because the connection between the buffer section 21 and the opening section 20 is relatively thin, if T is less than 0.2 mm, the bursting section 200 is too close to the edge of the buffer section 21, which can easily tear the opening section 20, making molding difficult. At the same time, the bursting section 200 is too close to the cover plate body 1, making it susceptible to the effects of welding heat, thus affecting the product yield. If T is greater than 3 mm, the bursting section 200 is too far from the buffer section 21, which means that the bursting section 200 is offset towards the center of the opening section 20, reducing the opening area of ​​the opening section 20 and thus reducing the flow area when the explosion-proof valve 2 is opened.

[0055] In some embodiments, please refer to Figure 9 On a plane perpendicular to the thickness direction of the cover plate body 1, the distance C between the orthographic projection of the first buffer segment 210 of the buffer part 21 and the orthographic projection of the cover plate body 1 satisfies: C ≥ 1 mm. For example, C can be 1 mm, 2 mm, 2.5 mm, 3 mm, 3.2 mm, 3.5 mm, 4 mm, 5 mm, 6 mm, 7 mm, 10 mm, 15 mm, etc., or any value between any two of the above. This improves the yield of the cover plate body 1 and the explosion-proof valve 2, ensuring that the opening pressure of the explosion-proof valve 2 meets the design requirements. When C is less than 1 mm, it will cause greater edge deformation of the cover plate body 1 when welding it to the housing 1001, reducing the product yield.

[0056] In some embodiments, please refer to Figure 8 Along the thickness direction of the cover body 1, the thickness of the opening portion 20 is D, satisfying 0.15mm ≤ D ≤ 0.4mm. It can be understood that the thickness D of the opening portion 20 refers to the thickness of the body of the opening portion 20. For example, D can take values ​​of 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, etc., or any value between any two of the above. This design ensures that the opening portion 20 has sufficient structural strength, is not easily deformed by welding heat, and allows the opening portion 20 to be easily opened when the internal pressure of the battery cell reaches a threshold, thus improving safety.

[0057] Specifically, when D is less than 0.15 mm, the structural strength of the opening part 20 is insufficient, making it prone to deformation under heat and reducing reliability. When D is greater than 0.4 mm, the structural strength of the opening part 20 is too high, which may cause the explosion-proof valve 2 to fail to open when the internal pressure of the battery cell reaches the threshold, thus losing its safety protection function. By controlling D within the above range, it can be ensured that the opening part 20 has appropriate strength, is not easily deformed, and can maintain a stable opening pressure threshold, allowing it to open normally when needed.

[0058] In some embodiments, please refer to Figure 7 and Figure 8The thickness of the second buffer section 211 is T1, satisfying: D ≤ T1 ≤ 2D. For example, T1 = D, 1.1D, 1.2D, 1.4D, 1.7D, 1.9D, or 2D, or any value between any two of the above. Specifically, when T1 is less than D, the wall thickness of the second buffer section 211 is too thin, making it prone to deformation and causing a deviation in the opening pressure of the explosion-proof valve 2. When T1 is greater than 2D, the wall thickness of the second buffer section 211 is too thick, increasing the difficulty of stamping and forming. By controlling T1 within the range of D to 2D, it can be ensured that the second buffer section 211 has sufficient structural strength while facilitating forming.

[0059] In some embodiments, please refer to Figure 8 The bending segment 214 can be arc-shaped, with an inner radius of radius R satisfying: 0.5×T1≤R≤3×T1. For example, R = 0.5×T1, 0.8×T1, T1, 1.4×T1, 1.6×T1, 2×T1, 2.4×T1, 2.8×T1, 3×T1, etc., or any value between any two of the above. Specifically, when R is less than 0.5×T1, the bending radius of the bending segment 214 is too small. During stamping, the small radius leads to severe stress concentration, making bending difficult and prone to micro-cracks or direct cracking, severely affecting the yield. When R is greater than 3×T1, bending becomes difficult, affecting the forming of the explosion-proof valve 2. By controlling R within the range of 0.5×T1 to 3×T1, a smooth bending transition can be achieved, improving the forming yield and structural reliability.

[0060] In some embodiments, please refer to Figure 7 and Figure 8 The thickness of the fourth buffer section 213 is T2, satisfying: T1≤T2≤3×T1. For example, T2 = T1, 1.4×T1, 1.6×T1, 2×T1, 2.4×T1, 2.8×T1, 3×T1, etc., or any value between any two of the above. Specifically, when T2 is less than T1, the thickness of the fourth buffer section 213 will be too thin, resulting in weak structural strength and a deviation in the opening pressure of the explosion-proof valve 2; when T2 is greater than 3×T1, the thickness of the fourth buffer section 213 will be too thick, making bending difficult and increasing the molding difficulty.

[0061] In some embodiments, please refer to Figure 7 and Figure 8 The thickness of the third buffer section 212 is T3, satisfying: T1≤T3≤2×T2. For example, T3 = T1, T2, 2×T2, or any value between any two of the above. Specifically, when T3 is less than T1, the thickness of the third buffer section 212 is too thin, making it prone to deformation and difficult to form. When T3 is greater than 3×T2, the thickness of the third buffer section 212 is too thick, making it difficult to form the explosion-proof valve 2.

[0062] In some embodiments, please refer to Figure 7 and Figure 8 The thickness of the first buffer section 210 is T4, satisfying: T1≤T4≤0.6×A1. For example: T4=T1, 0.1×A1, 0.5×A1, or 0.6×A1. Specifically, when T4 is less than T1, the thickness of the first buffer section 210 is too thin, the structural strength of the first buffer section 210 is weak, and the pressure-bearing capacity is too weak, causing the first buffer section 210 to be prone to cracking. When T4 is greater than 0.6×A1, the thickness of the first buffer section 210 is too thick, affecting the molding of the explosion-proof valve 2.

[0063] In some embodiments, please refer to Figure 5 To further improve the structural strength of the opening portion 20, a reinforcing portion 22 is provided, which is a protruding structure extending along the thickness direction of the cover plate body 1. In some embodiments, the reinforcing portion 22 can be a solid structure or a hollow structure. The reinforcing portion 22 can protrude simultaneously toward the first surface 10 and the second surface 11, or it can protrude alone toward the first surface 10 or alone toward the second surface 11. Thus, the reinforcing portion 22 increases the rigidity of the opening portion 20, thereby improving its resistance to deformation and reducing the risk of deformation of the opening portion 20 when heated.

[0064] In some embodiments, to further improve the deformation resistance of the opening portion 20, the reinforcing portion 22 may include at least one, such as one, two, three, four, etc. For example Figure 5 In the illustrated embodiment, the reinforcing part 22 is located in the central region of the opening part 20 and has a solid structure that protrudes towards both the first surface 10 and the second surface 11. This enhances the bending resistance of the opening part 20 under pressure loads, allowing it to maintain a more stable planar shape before reaching the set opening pressure threshold. This ensures that pressure is transmitted more evenly and predictably to the surrounding preset bursting sections 200, improving the stability and safety of the explosion-proof valve 2.

[0065] In some embodiments, please refer to Figure 10 or Figure 11 The outline shape of the explosion-proof valve 2 includes, but is not limited to, a circle or an ellipse.

[0066] The technical solution of this application will be described below with reference to the embodiments.

[0067] To further verify the influence of the included angle α between the first wall surface 2111 of the second buffer section 211 and the first opening surface 201 of the opening part 20 on the explosion-proof valve 2, this application studied the stamping forming experiment of the explosion-proof valve under different included angle α conditions. The specific experimental parameters and results are shown in Table 1.

[0068] Table 1 As shown in Table 1, in Example 1, the angle α is 70°, which is less than 90° and does not meet the requirement of 90°≤a≤180°. Therefore, it is difficult to form the explosion-proof valve during stamping and is not recommended. In Examples 2-8, the included angle α is within the range of 90°-180°, satisfying 90°≤a≤180°. Therefore, the forming yield is ≥99.6% when stamping the explosion-proof valve. In Example 9, the included angle α is 200°, which is greater than 180° and does not meet the requirement of 90°≤a≤180°. Therefore, when stamping the explosion-proof valve, the edge of the explosion-proof valve bends downward, which may easily interfere with the cover plate body 1. It is not recommended. Thus, it is shown that when the included angle α is within the range of 90°≤a≤180°, it can ensure that the explosion-proof valve 2 is easy to form through the stamping process with a high yield, and it can also avoid interference with the cover plate body 1.

[0069] To further verify the influence of the position of the explosion-proof valve 2 along the thickness direction of the cover plate body 1 on the forming quality and spatial layout, this application embodiment studied the stamping experiment of explosion-proof valve 2 with A1, A2 and A of different sizes. The specific experimental parameters and results are shown in Table 2.

[0070] Table 2 As shown in Table 2 above, in Example 1, A1 is 2mm, A2 is 3.2mm, and A is -1.5mm. The value of A is too small, not satisfying the range of -0.5×A1≤A≤A2. During the stamping of explosion-proof valve 2, forming is difficult, and the defect rate is ≥5.6%. In Examples 2-13, A1 is 2mm, A2 is 3.2mm, and A ranges from -1mm to 3.2mm, satisfying the range of -0.5×A1≤A≤A2. The result is that during the stamping of the explosion-proof valve, the forming yield is ≥99.8%, and the opening pressure of the explosion-proof valve meets the requirements. In Example 14, A1 is 2mm, A2 is 3.2mm, and A is 3.6mm. The value of A is too large, not satisfying the range of -0.5×A1≤A≤A2. Result: During the stamping of the explosion-proof valve, the explosion-proof valve 2 was higher than the surface of the pole post 3, which affected the space utilization of the battery cell.

[0071] In Example 15, A1 is 1.5mm, A2 is 3.2mm, and A is -0.5mm, satisfying -0.5×A1≤A≤A2. In Example 16, A1 is 3mm, A2 is 3.2mm, and A is 0, meaning the buffer portion 21 of the explosion-proof valve 2 is flush with the first surface 10, satisfying -0.5×A1≤A≤A2. In Example 17, A1 is 2mm, A2 is 5mm, and A is 0mm, meaning the buffer portion 21 of the explosion-proof valve 2 is flush with the first surface 10, satisfying -0.5×A1≤A≤A2. In Example 18, A1 is 2mm, A2 is 2.2mm, and A is 0mm, meaning the buffer portion 21 of the explosion-proof valve 2 is flush with the first surface 10, satisfying -0.5×A1≤A≤A2. In Example 19, A1 is 2mm, A2 is 1mm, and A is 0mm, meaning the buffer portion 21 of the explosion-proof valve 2 is flush with the first surface 10, satisfying -0.5×A1≤A≤A2. In Example 20, A1 is 2mm, A2 is 0.2mm, and A is 0mm, meaning the buffer portion 21 of the explosion-proof valve 2 is flush with the first surface 10, satisfying -0.5×A1≤A≤A2. Results of Examples 15 to 20: During the stamping of the explosion-proof valve, the forming yield is ≥99.8%, and the opening pressure of the explosion-proof valve meets the requirements. This indicates that satisfying -0.5×A1≤A≤A2 ensures easy forming and high yield through the stamping process, while also avoiding impacting the internal space utilization of the battery cell.

[0072] To further verify the effects of the distance T between the orthographic projection of the blasting section 200 and the orthographic projection of the second buffer section 211 of the buffer section 21, and the distance C between the orthographic projection of the first buffer section 210 of the buffer section 21 and the orthographic projection of the cover body 1 on the manufacturing yield of the explosion-proof valve and the cover body, as well as the opening area of ​​the explosion-proof valve, this application studies the molding experiments of the explosion-proof valve and cover assembly with different T and C values. The specific experimental parameters and results are shown in Table 3.

[0073] Table 3 As shown in Table 3, in Example 1, T is 0mm and C is 5mm, meaning the bursting section 200 is close to the second buffer section 211 of the buffer part 21, and the distance between them is too small, failing to satisfy 0.2mm≤T≤3mm. Even if C≥1mm, this results in difficulty in forming the bursting section 200 of the explosion-proof valve, with a defect rate ≥10%. In Example 2, T is 1mm and C is 0.5mm. In this case, C <1mm, resulting in a small distance between the edge of the cover body 1 and the second buffer section 211 of the buffer part 21, leading to significant edge deformation of the cover body 1 and a dimensional defect rate ≥8.6%. In Examples 3 to 12, T is 0.2mm-3mm, satisfying 0.2mm≤T≤3mm, and C is ≥1mm. As a result, in Examples 3 to 12, the process yield of the cover body 1 and the explosion-proof valve 2 is ≥99.8%, and the opening pressure of the explosion-proof valve 2 meets the design requirements. In Example 13, T is set to 5mm, which is too large and does not meet the requirement of 0.2mm≤T≤3mm. C is set to 3mm. This results in the blasting section 200 being too close to the center of the opening part 20, affecting the opening area of ​​the opening part 20 of the explosion-proof valve 2. This method is not recommended. In Examples 14 to 17, T is set to 2mm, satisfying 0.2mm≤T≤3mm, and C is set to ≥1mm. As a result, in Examples 14 to 17, the process yield of the cover body 1 and the explosion-proof valve 2 is ≥99.8%, and the opening pressure of the explosion-proof valve 2 meets the design requirements. In Example 18, T is set to 2mm, satisfying 0.2mm≤T≤3mm; C is set to 20mm. This results in the distance between the edge of the cover body 1 and the second buffer section 211 of the buffer part 21 being too large, which will affect the opening area of ​​the explosion-proof valve 2 or the design of the cover body 1. This method is not recommended.

[0074] To further verify the influence of the thickness T1 of the second buffer section 211 and the thickness D of the opening part 20 on the molding and opening of the explosion-proof valve, this application conducted stamping experiments and explosion-proof valve opening experiments on second buffer sections 211 of different thicknesses and opening parts 20 of different thicknesses. The specific experimental parameters and results are shown in Table 4.

[0075] Table 4 As shown in Table 4 above, in Example 1, D is 0.15mm and T1 is 0.1mm. The value of T1 is too small, failing to meet the range of D≤T1≤2D. This results in the second buffer section 211 being easily deformed, and the opening pressure of the explosion-proof valve 2 easily deviating, failing to meet design requirements. In Examples 2 to 11, D is 0.15mm and T1 is between 0.15mm and 0.3mm, satisfying the range of D≤T1≤2D. Therefore, in Examples 2 to 11, the opening pressure of the explosion-proof valve 2 can meet design requirements, and the molding yield of the explosion-proof valve 2 is ≥99.6%. In Example 12, D is 0.15mm and T1 is 5mm. The value of T1 is too large, failing to meet the range of D≤T1≤2D. Therefore, the thickness of the second buffer section 211 is too thick, making the molding of the explosion-proof valve 2 difficult and affecting its molding. In Example 13, D is 0.2 mm and T is 0.25 mm, satisfying D ≤ T1 ≤ 2D. In Example 14, D is 0.25 mm and T is 0.3 mm, satisfying D ≤ T1 ≤ 2D. In Example 15, D is 0.4 mm and T is 0.45 mm, satisfying D ≤ T1 ≤ 2D. Therefore, in Examples 13 to 15, the opening pressure of the explosion-proof valve 2 can meet the design requirements, and the molding yield of the explosion-proof valve 2 is ≥ 99.7%.

[0076] To further verify the effects of the thickness A1 of the cover plate body 1, the thickness T1 of the second buffer section 211, the inner radius R of the bending section 214, the thickness T2 of the fourth buffer section 213, the thickness T3 of the third buffer section 212, and the thickness T4 of the first buffer section 210 on the forming and opening of the explosion-proof valve 2, this application studies the stamping experiments and explosion-proof valve opening experiments conducted on the first buffer section 210, the second buffer section 211, the third buffer section 212, the fourth buffer section 213, the cover plate body 1, and the bending section 214 with different inner radii. Specific experimental parameters and results are shown in Table 5.

[0077] Table 5 As shown in Table 5 above, in Example 1, A1 is 2mm, T1 is 0.3mm, R is 0.1mm, T2 is 0.3mm, T3 is 0.5mm, and T4 is 0.5mm. This satisfies T1≤T2≤3×T1, T1≤T3≤2×T2, and T1≤T4≤0.6×A1. However, the value of R is too small and does not satisfy 0.5×T1≤R≤3×T1. This results in a small bending radius for the bending section 214, making bending difficult and prone to cracking, leading to a failure rate of ≥9.55% for the explosion-proof valve 2.

[0078] In Example 2, A1 is 2mm, T1 is 0.3mm, R is 0.15mm, T2 is 0.15mm, T3 is 0.5mm, and T4 is 0.5mm. However, because the thickness T2 of the fourth buffer section 213 is too small, it does not satisfy T1≤T2≤3×T1, although it satisfies T1≤T4≤0.6×A1 and 0.5×T1≤R≤3×T1. This will cause the fourth buffer section 213 to be easily deformed, and the opening pressure of the explosion-proof valve 2 to deviate, failing to meet the design requirements.

[0079] In Example 3, A1 is 2mm, T1 is 0.3mm, R is 0.16mm, T2 is 0.3mm, T3 is 0.15mm, and T4 is 0.5mm. Although the conditions T1≤T2≤3×T1, T1≤T4≤0.6×A1, and 0.5×T1≤R≤3×T1 are met, the thickness T3 of the third buffer section 212 is too small, failing to meet the range T1≤T3≤2×T2. This results in a thin wall thickness for the third buffer section 212, making molding difficult, and its use is not recommended.

[0080] In Example 4, A1 is 2mm, T1 is 0.3mm, R is 0.17mm, T2 is 0.3mm, T3 is 0.5mm, and T4 is 0.15mm. This satisfies T1≤T2≤3×T1, T1≤T3≤2×T2, and 0.5×T1≤R≤3×T1. However, the thickness T4 of the first buffer section 210 is too small, failing to satisfy T1≤T4≤0.6×A1. This results in a thin wall thickness for the first buffer section 210, weak compressive strength, and a tendency to crack; therefore, its use is not recommended.

[0081] In Examples 5 to 11, A1 is always 2 mm, T1 is always 0.3 mm, R is always 0.15 mm - 0.9 mm, T2 is always 0.3 mm - 0.7 mm, T3 is always 0.6 mm - 0.9 mm, and T4 is always 0.3 mm - 1.2 mm. All satisfy the following conditions: T1 ≤ T2 ≤ 3 × T1, T1 ≤ T3 ≤ 2 × T2, T1 ≤ T4 ≤ 0.6 × A1, and 0.5 × T1 ≤ R ≤ 3 × T1. Therefore, in Examples 5 to 10, the opening pressure of the explosion-proof valve 2 meets the design requirements, and the molding yield of the explosion-proof valve 2 is ≥ 99.75%.

[0082] In Example 12, A1 is 2mm, T1 is 0.3mm, R is 0.5mm, T2 is 0.6mm, T3 is 0.8mm, and T4 is 2mm. Although T1≤T2≤3×T1, T1≤T3≤2×T2, and 0.5×T1≤R≤3×T1 are satisfied, the thickness T4 of the first buffer section 210 is too large, failing to satisfy T1≤T4≤0.6×A1. This results in the first buffer section 210 being too thick, affecting the molding of the explosion-proof valve 2.

[0083] In Example 13, A1 is 2mm, T1 is 0.3mm, R is 0.3mm, T2 is 1.5mm, T3 is 1.5mm, and T4 is 1.5mm. Although T1≤T3≤2×T2, T1≤T4≤0.6×A1, and 0.5×T1≤R≤3×T1 are satisfied, the thickness T2 of the fourth buffer section 213 is too large, failing to satisfy T1≤T2≤3×T1. This makes bending the fourth buffer section 213 difficult, hindering the formation of the explosion-proof valve 2, and its use is not recommended.

[0084] In Example 14, A1 is 2mm, T1 is 0.3mm, R is 2mm, T2 is 2mm, T3 is 2mm, and T4 is 2mm. Although T1≤T2≤3×T1, T1≤T3≤2×T2, and T1≤T4≤0.6×A1 are satisfied, the inner radius R of the bent section 214 is too large, failing to satisfy 0.5×T1≤R≤3×T1. This results in the buffer section 21 being unable to be formed.

[0085] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A cover plate assembly, characterized in that, include: Cover plate body; An explosion-proof valve is disposed on the cover plate body and integrally formed with the cover plate body. The explosion-proof valve includes an opening part and a buffer part. The buffer part is arranged circumferentially around the opening part. The opening part is provided with a burst section. The buffer part includes at least a first buffer section and a second buffer section. The first buffer section is connected to the cover plate body, and the second buffer section is connected to the opening part. The second buffer section has a first wall surface. The opening part has a first opening surface connected to the first wall surface. The included angle between the first wall surface and the first opening surface is α, which satisfies: 90°≤α≤180°.

2. The cover plate assembly according to claim 1, characterized in that, Also includes: An electrode post is disposed on the cover plate body, the cover plate body includes a first surface and a second surface, the first surface and the second surface are disposed opposite to each other along the thickness direction of the cover plate body, at least a portion of the electrode post protrudes from the first surface and forms a first electrical connection surface, the distance between the first electrical connection surface and the first surface along the thickness direction of the cover plate body is A2, the thickness of the cover plate body is A1, and the distance between the end of the buffer portion away from the cover plate body and the first surface is A, satisfying: -0.5×A1≤A≤A2.

3. The cover plate assembly according to claim 1, characterized in that, On a plane perpendicular to the thickness direction of the cover plate body, the distance T between the orthographic projection of the explosive section and the orthographic projection of the second buffer section of the buffer part satisfies: 0.2mm ≤ T ≤ 3mm; and / or, On a plane perpendicular to the thickness direction of the cover plate body, the distance between the orthographic projection of the first buffer segment of the buffer part and the orthographic projection of the cover plate body is C, which satisfies C≥1mm.

4. The cover plate assembly according to claim 1, characterized in that, Along the thickness direction of the cover plate body, the thickness of the opening portion is D, satisfying 0.15mm ≤ D ≤ 0.4mm; and / or, The thickness of the second buffer segment is T1, which satisfies: D≤T1≤2D.

5. The cover plate assembly according to claim 4, characterized in that, The buffer section further includes a bending section, a third buffer section, and a fourth buffer section; wherein the first buffer section, the third buffer section, the fourth buffer section, the bending section, and the second buffer section are sequentially connected from the cover plate body to the opening section.

6. The cover plate assembly according to claim 5, characterized in that, The first buffer section extends along a direction perpendicular to the thickness of the cover plate body. One end of the third buffer section is connected to the first buffer section, and the other end of the third buffer section extends along the thickness of the cover plate body. One end of the fourth buffer section is connected to the third buffer section, and the other end of the fourth buffer section is inclined away from the opening. One end of the second buffer section is connected to the fourth buffer section through the bending section, and the other end of the second buffer section is inclined towards the opening.

7. The cover plate assembly according to claim 5, characterized in that, The inner radius of the bent section is R, satisfying: 0.5×T1≤R≤3×T1; and / or, The thickness of the fourth buffer segment is T2, satisfying: T1≤T2≤3×T1; and / or, The thickness of the third buffer segment is T3, satisfying: T1≤T3≤2×T2; and / or, The thickness of the first buffer section is T4, and the thickness of the cover plate body is A1, satisfying: T1≤T4≤0.6×A1.

8. The cover plate assembly according to claim 1, characterized in that, The opening part is provided with a reinforcing part, which is a protruding structure that protrudes along the thickness direction of the cover plate body.

9. A single battery cell, characterized in that, include: A housing having an opening; The cover assembly according to any one of claims 1 to 8 is connected to the opening of the housing.

10. An electrical appliance, characterized in that, include: Electricity-consuming entities; At least one battery cell according to claim 9, wherein the battery cell is electrically connected to the power-consuming body.

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