A high-strength top cover assembly and battery

Abstract

This utility model relates to a high-strength top cover assembly and a battery. The high-strength top cover assembly includes a composite top cover sheet, a lower plastic component, and an upper plastic component. The composite top cover sheet includes a stainless steel top cover sheet and an aluminum top cover sheet. The aluminum top cover sheet is stacked on the stainless steel top cover sheet, and the stainless steel top cover sheet is stacked on the lower plastic component. The aluminum top cover sheet has several openings, and the upper plastic component passes through these openings and connects to the stainless steel top cover sheet. The advantages of this utility model are its thinness, light weight, and ability to prevent deformation of the top cover sheet and reduce the risk of welding cracks.

Description

Technical Field

[0001] This utility model relates to the field of battery top cover technology, specifically to a high-strength top cover assembly and battery. Background Technology

[0002] As market demands for power battery energy density continue to rise, the inverted battery installation solution has emerged. While this solution can improve energy density to some extent, it also presents more stringent challenges to the top cover assembly.

[0003] When batteries are installed in reverse, the top cover needs to support the weight of components such as battery cells, adapter plates, and electrolyte, and also withstand the bumps and vibrations during vehicle operation. However, the strength of existing top covers is generally insufficient to meet these requirements, leading to the risk of cracking and leakage at the welded positions of the battery casing. Some top covers are made of 3003-H14 aluminum, and when the length of the top cover is large, the middle position is prone to deformation. This deformation will affect the consistency of the effective penetration depth of laser welding during casing welding, thereby increasing the risk of cracking at the welded position.

[0004] Furthermore, as the industry's requirements for battery energy density continue to increase, the external dimensions of battery cells are gradually increasing, and their volume and weight are also increasing accordingly. In order to meet the requirements for conductive current, the connecting piece connected to the top cover plate has become thicker, which further increases the requirements for the support strength of the top cover plate. Utility Model Content

[0005] The purpose of this invention is to provide a high-strength top cover assembly and battery that is thin, lightweight, and can prevent deformation of the top cover sheet and reduce the risk of welding cracks.

[0006] A high-strength top cover assembly includes a composite top cover sheet, a lower plastic component, and an upper plastic component. The composite top cover sheet includes a stainless steel top cover sheet and an aluminum top cover sheet. The aluminum top cover sheet is stacked on the stainless steel top cover sheet, and the stainless steel top cover sheet is stacked on the lower plastic component. The aluminum top cover sheet has a plurality of openings, and the upper plastic component passes through the openings and is connected to the stainless steel top cover sheet.

[0007] In the above solution, stainless steel itself has high strength, good rigidity and resistance to deformation. The lower plastic is connected to the stainless steel top cover, and the upper plastic component passes through the opening on the aluminum top cover and is connected to the stainless steel top cover. In this way, the middle position of the aluminum top cover will not deform, reducing the risk of cracking at the welding position. Due to the light weight of aluminum, the composite top cover formed by the combination of stainless steel and aluminum top cover fully utilizes the advantages of each, making the top cover assembly lighter overall while having higher strength. Compared with traditional top cover that requires thicker materials to meet strength requirements, the composite top cover can achieve a thinner thickness and lighter weight while ensuring strength.

[0008] Furthermore, the stainless steel top cover sheet has multiple thinning structures formed by stamping on its surface.

[0009] In the above scheme, the stainless steel top cover sheet is stamped to thin the structure. Its plastic deformation leads to a large number of dislocations multiplying and entangled, grain morphology fibrosis and internal stress accumulation. These microstructural changes together increase the resistance to atomic slip, so that the material can only deform under higher external force, thereby significantly improving the strength of the composite top cover sheet.

[0010] Furthermore, the thinning structure has a hexagonal honeycomb shape.

[0011] In the above scheme, the hexagonal honeycomb shape has an excellent spatial truss effect, which can evenly distribute the stress acting on the top cover to all directions. In the actual working scenario of the battery, when subjected to complex stresses such as cell expansion and external extrusion, each side and corner of the hexagon can serve as a stress transmission node, so that the force is evenly distributed in six directions, avoiding excessive stress concentration in local areas. Adjacent sides restrain each other, forming a stable mechanical structure. This greatly reduces the risk of deformation and cracking of the top cover due to excessive local stress, and significantly improves the reliability and stability of the composite top cover under complex working conditions.

[0012] Furthermore, the aluminum top cover sheet has mounting bosses on its four sides, and the mounting bosses are pressed against the four sides of the stainless steel top cover sheet.

[0013] In the above scheme, the design of the mounting boss provides a clear positioning and connection method for the assembly of the aluminum top cover and the stainless steel top cover, reducing the assembly difficulty and improving production efficiency. During the battery use, the battery will be subjected to various external forces, such as vibration and impact. The mounting boss is pressed on the four sides of the stainless steel top cover, which can effectively resist these external forces, prevent the aluminum top cover and the stainless steel top cover from separating from each other or from being relatively displaced, and ensure the integrity and stability of the battery structure.

[0014] Furthermore, a metal coating is provided at the interface between the stainless steel top cover and the aluminum top cover, and the metal coating has good compatibility with the stainless steel and aluminum.

[0015] In the above solution, when aluminum and stainless steel are directly welded, brittle intermetallic compounds are easily formed at the interface, which makes the weld prone to cracking and failure. However, the metal coating has good compatibility with the materials on both sides, creating a tough transition zone and avoiding the formation of brittle phases when aluminum and stainless steel come into direct contact. This fundamentally solves the problem of interface brittleness and improves the strength and reliability of the connection between the aluminum top cover and the stainless steel top cover.

[0016] Furthermore, the upper plastic assembly includes a positive electrode upper plastic and a negative electrode upper plastic, with a positive electrode aluminum block mounted on the positive electrode upper plastic and a negative electrode aluminum block mounted on the negative electrode upper plastic.

[0017] In the above scheme, the positive and negative aluminum blocks, as key conductive components of the positive and negative electrodes of the battery, have good conductivity. Aluminum has excellent conductivity, which can effectively reduce resistance, reduce energy loss during transmission, and improve the charging and discharging efficiency of the battery. The upper plastic component provides a stable support structure for the positive and negative aluminum blocks. The plastic material has a certain strength and toughness, which can withstand the external forces on the positive and negative aluminum blocks during use and prevent the positive and negative aluminum blocks from shifting or deforming.

[0018] Furthermore, the positive electrode has a first groove on the plastic surface, the negative electrode has a second groove on the plastic surface, the positive electrode aluminum block is embedded in the first groove, and the negative electrode aluminum block is embedded in the second groove.

[0019] In the above scheme, the design of the first and second grooves provides precise installation positions for the positive and negative aluminum blocks. During the battery production and assembly process, this precise positioning can effectively avoid the problem of installation offset or misalignment of the positive and negative aluminum blocks, thereby improving production efficiency and product quality consistency.

[0020] Furthermore, it also includes a positive electrode post and a negative electrode post. One end of the positive electrode post passes through the lower plastic, the composite top cover, and the upper positive plastic and is riveted to the positive aluminum block. One end of the negative electrode post passes through the lower plastic, the composite top cover, and the upper negative plastic and is riveted to the negative aluminum block.

[0021] In the above scheme, the positive and negative terminals pass through the lower plastic, composite top cover, and upper plastic assembly in sequence and are riveted to the positive and negative aluminum blocks, tightly connecting the various components of the battery together to form an integrated mechanical structure. This connection method enhances the structural strength and stability of the battery top cover assembly, enabling it to better withstand external pressure, impact, and vibration, reducing the risk of component damage or separation due to mechanical stress, and improving the battery's anti-interference ability and service life.

[0022] Furthermore, it also includes sealing rings, with two sealing rings respectively fitted onto the positive terminal and the negative terminal.

[0023] In the above solution, the electrolyte inside the battery is corrosive. If leakage occurs, it will not only damage the equipment around the battery, but may also cause safety accidents. The sealing ring can form a tight seal at the connection between the positive terminal, the negative terminal and the surrounding components, effectively preventing the electrolyte from seeping out and ensuring a stable environment for the chemical substances inside the battery.

[0024] A battery comprising a high-strength top cover assembly as described in any of the above embodiments.

[0025] This utility model discloses a high-strength top cover assembly and battery, which features thinness, light weight, and the advantages of avoiding deformation of the top cover sheet and reducing the risk of welding cracks. Stainless steel itself has high strength, good rigidity, and resistance to deformation. The lower plastic assembly is connected to the stainless steel top cover sheet, and the upper plastic assembly passes through the opening in the aluminum top cover sheet and connects to the stainless steel top cover sheet. This prevents deformation in the middle of the aluminum top cover sheet and reduces the risk of cracking at the welding point. Due to the light weight of aluminum, the composite top cover sheet formed by the combination of the stainless steel and aluminum top cover sheets fully utilizes the advantages of each, making the top cover assembly lighter overall while having higher strength. Compared with traditional top cover sheets that require thicker materials to meet strength requirements, the composite top cover sheet can achieve a thinner thickness and lighter weight while ensuring strength. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the top cover assembly according to one embodiment.

[0027] Figure 2 This is a schematic diagram of an aluminum top cover sheet of a composite top cover sheet according to one embodiment.

[0028] Figure 3 This is a schematic diagram of a stainless steel top cover sheet of a composite top cover sheet according to one embodiment.

[0029] Figure 4 This is a schematic diagram showing the connection between the upper plastic component, the positive aluminum block, and the negative aluminum block in one embodiment.

[0030] Figure 5 This is a schematic diagram of the plastic structure on the positive electrode and the plastic structure on the negative electrode in one embodiment.

[0031] Figure 6 This is a schematic diagram of the connection between the positive and negative terminals in one embodiment.

[0032] Figure 7 This is a schematic diagram of the connection between the positive electrode post and the sealing ring in one embodiment.

[0033] Explanation of reference numerals: 1. Lower plastic; 2. Composite top cover sheet; 21. Aluminum top cover sheet; 22. Stainless steel top cover sheet; 211. Window; 212. Assembly boss; 221. Thinning structure; 3. Upper plastic assembly; 31. Positive electrode upper plastic; 311. First groove; 32. Negative electrode upper plastic; 321. Second groove; 4. Positive electrode aluminum block; 5. Negative electrode aluminum block; 6. Positive electrode post; 7. Negative electrode post; 8. Sealing ring. Detailed Implementation

[0034] The following will describe in further detail a high-strength top cover assembly and battery of the present invention with reference to specific embodiments and accompanying drawings.

[0035] like Figures 1 to 3 As shown in a preferred embodiment, a high-strength top cover assembly of the present invention includes a composite top cover sheet 2, a lower plastic sheet 1, and an upper plastic assembly 3. The composite top cover sheet 2 includes a stainless steel top cover sheet 22 and an aluminum top cover sheet 21. The aluminum top cover sheet 21 is stacked on the stainless steel top cover sheet 22, and the stainless steel top cover sheet 22 is stacked on the lower plastic sheet 1. The aluminum top cover sheet 21 is provided with a plurality of openings 211, and the upper plastic assembly 3 passes through the openings 211 and is connected to the stainless steel top cover sheet 22.

[0036] Stainless steel itself has high strength, good rigidity and resistance to deformation. The lower plastic 1 is connected to the stainless steel top cover plate 22, and the upper plastic component 3 passes through the opening 211 on the aluminum top cover plate 21 and is connected to the stainless steel top cover plate 22. In this way, the middle position of the aluminum top cover plate 21 will not be deformed, reducing the problem of inconsistent effective penetration depth of laser welding caused by the deformation of the top cover plate, reducing the risk of cracking at the welding position, and improving welding quality and production efficiency. Since aluminum is lightweight, the composite top cover plate 2 formed by the combination of stainless steel top cover plate 22 and aluminum top cover plate 21 fully utilizes the advantages of each, making the top cover assembly lighter overall while having higher strength. Compared with traditional top cover plates that require thicker materials to meet strength requirements, the composite top cover plate 2 can achieve a thinner thickness and lighter weight while ensuring strength.

[0037] In practical applications of batteries, especially when using an inverted battery installation scheme, the top cover sheet needs to bear the weight of components such as the battery cells, adapter plates, and electrolyte, as well as withstand the bumps and vibrations during vehicle operation. The composite top cover sheet 2 has higher strength and can better withstand these external forces, reducing the risk of deformation and damage, ensuring the stability and integrity of the battery structure, reducing the possibility of cracking and leakage at the battery casing weld, and improving the safety and reliability of the battery.

[0038] like Figure 3 As shown, in some embodiments, multiple thinning structures 221 are stamped onto the surface of the stainless steel top cover sheet 22. The plastic deformation caused by stamping the thinning structures 221 onto the surface of the stainless steel top cover sheet 22 leads to a large number of dislocations multiplying and entangled, grain morphology fibrosis, and internal stress accumulation. These microstructural changes collectively increase the resistance to atomic slip, requiring the material to deform under higher external forces, thereby significantly improving the strength of the composite top cover sheet 2. In practical use, it can better withstand external forces such as compression and impact, protecting the internal structure of the battery from damage and extending the battery's lifespan.

[0039] like Figure 3As shown, in some embodiments, the thinning structure 221 is in the form of a hexagonal honeycomb shape. The hexagonal honeycomb shape has an excellent spatial truss effect, which can evenly distribute the stress acting on the top cover to all directions. In the actual working scenario of the battery, when subjected to complex stresses such as cell expansion and external compression, each side and corner of the hexagon can serve as a stress transmission node, so that the force is evenly distributed through six directions, avoiding excessive stress concentration in local areas. Adjacent sides restrain each other, forming a stable mechanical structure. This greatly reduces the risk of deformation and cracking of the top cover sheet due to excessive local stress, and significantly improves the reliability and stability of the composite top cover sheet 2 under complex working conditions.

[0040] like Figure 3 As shown, in some embodiments, the aluminum top cover 21 has mounting bosses 212 on its four sides, which press against the four sides of the stainless steel top cover 22. The design of the mounting bosses 212 provides a clear positioning and connection method for the assembly of the aluminum top cover 21 and the stainless steel top cover 22, reducing assembly difficulty and improving production efficiency. During battery use, the battery will be subjected to various external forces, such as vibration and impact. The mounting bosses 212 pressing against the four sides of the stainless steel top cover 22 can effectively resist these external forces, prevent the aluminum top cover 21 and the stainless steel top cover 22 from separating from each other or undergoing relative displacement, and ensure the integrity and stability of the battery structure.

[0041] like Figure 2 As shown, in some embodiments, a metal coating is provided at the interface between the stainless steel top cover plate 22 and the aluminum top cover plate 21. The metal coating has good compatibility with both stainless steel and aluminum. When aluminum and stainless steel are directly welded, brittle intermetallic compounds are easily formed at the interface, leading to easy cracking and failure of the weld. However, the metal coating, such as copper or nickel, has good compatibility with the materials on both sides, creating a ductile transition zone and preventing the formation of brittle phases through direct contact between aluminum and stainless steel. This fundamentally solves the problem of interface brittleness and improves the strength and reliability of the connection between the aluminum top cover plate 21 and the stainless steel top cover plate 22.

[0042] The specific process for producing the composite top cover sheet 2 is as follows: first, a stainless steel top cover sheet 22 and an aluminum top cover sheet 21 are stamped out separately. The stainless steel top cover sheet 22 has multiple thinned structures 221 formed on its surface by stamping. A layer of metal with good compatibility with stainless steel and aluminum, such as nickel or copper, is pre-coated on the surface of the stainless steel top cover sheet 22. The thickness of the coating is controlled between 5-30μm. The coated stainless steel top cover sheet 22 and the aluminum top cover sheet 21 are hot-pressed and welded together. By heating and applying pressure, the contact surface of the two is plastically deformed and atomic diffusion bonding is achieved, thus fusing them together.

[0043] The specific process parameters for the hot-press welding between the stainless steel top cover plate 22 and the aluminum top cover plate 21 are as follows: Temperature: The temperature should be between the recrystallization temperature of aluminum (about 350℃) and the softening temperature of stainless steel (about 800℃), usually 350-500℃, which is about 0.6-0.8 times the melting point of aluminum.

[0044] Pressure: The pressure should cause plastic deformation at the contact surface to break the oxide film, but excessive extrusion and loss of aluminum should be avoided at the same time. Depending on the material thickness (0.5-1mm), the pressure is usually controlled between 5-20MPa.

[0045] Holding time: The holding time should provide sufficient time for atomic diffusion, and is usually set between 30 and 300 seconds.

[0046] like Figure 4 As shown, in some embodiments, the upper plastic assembly 3 includes a positive electrode upper plastic 31 and a negative electrode upper plastic 32. A positive electrode aluminum block 4 is mounted on the positive electrode upper plastic 31, and a negative electrode aluminum block 5 is mounted on the negative electrode upper plastic 32. The positive electrode aluminum block 4 and the negative electrode aluminum block 5, as key conductive components of the battery's positive and negative electrodes, have good conductivity. Aluminum has excellent conductivity, which can effectively reduce resistance, reduce energy loss during transmission, and improve the battery's charging and discharging efficiency. The upper plastic assembly 3 provides a stable support structure for the positive electrode aluminum block 4 and the negative electrode aluminum block 5. The plastic material has a certain strength and toughness, capable of withstanding external forces on the positive electrode aluminum block 4 and the negative electrode aluminum block 5 during use, preventing displacement or deformation of the positive electrode aluminum block 4 and the negative electrode aluminum block 5.

[0047] like Figure 5 As shown, in some embodiments, a first groove 311 is provided on the plastic 31 of the positive electrode, and a second groove 321 is provided on the plastic 32 of the negative electrode. The positive electrode aluminum block 4 is embedded in the first groove 311, and the negative electrode aluminum block 5 is embedded in the second groove 321. The design of the first groove 311 and the second groove 321 provides a precise installation position for the positive electrode aluminum block 4 and the negative electrode aluminum block 5. During the battery production and assembly process, this precise positioning can effectively avoid the problem of installation misalignment or displacement of the positive electrode aluminum block 4 and the negative electrode aluminum block 5, thereby improving production efficiency and product quality consistency.

[0048] In this embodiment, the negative electrode aluminum block 5 can be a copper-aluminum composite block. This composite structure utilizes the lightweight advantage of aluminum and combines the excellent electrical and thermal conductivity of copper, reducing costs while ensuring performance.

[0049] like Figure 6As shown, in some embodiments, the battery also includes a positive electrode post 6 and a negative electrode post 7. One end of the positive electrode post 6 passes through the lower plastic 1, the composite top cover sheet 2, and the upper positive plastic 31 and is riveted to the positive aluminum block 4. One end of the negative electrode post 7 passes through the lower plastic 1, the composite top cover sheet 2, and the upper negative plastic 32 and is riveted to the negative aluminum block 5. The positive electrode post 6 and the negative electrode post 7 pass through the lower plastic 1, the composite top cover sheet 2, and the upper plastic assembly 3 in sequence and are riveted to the positive aluminum block 4 and the negative aluminum block 5, tightly connecting the various components of the battery together to form an integrated mechanical structure. This connection method enhances the structural strength and stability of the top cover assembly, enabling it to better withstand external pressure, impact, and vibration, reducing the risk of component damage or separation due to mechanical stress, and improving the battery's anti-interference capability and service life.

[0050] like Figure 6 and Figure 7 As shown, in some embodiments, a sealing ring 8 is also included, with two sealing rings 8 respectively fitted onto the positive terminal 6 and the negative terminal 7. The electrolyte inside the battery is corrosive; if leakage occurs, it will not only damage the equipment around the battery but may also cause a safety accident. The sealing rings 8 can form a tight seal at the connection between the positive terminal 6, the negative terminal 7 and the surrounding components, effectively preventing electrolyte leakage and ensuring a stable chemical environment inside the battery.

[0051] A battery comprising a high-strength top cover assembly as described in any of the above embodiments.

[0052] This utility model discloses the working principle and process of a high-strength top cover assembly and battery. The stainless steel top cover sheet 22 and the aluminum top cover sheet 21 formed by stamping are welded together by hot pressure welding to form a composite top cover sheet 2. When the top cover assembly is subjected to external pressure or impact, the stainless steel top cover sheet 22 bears the main load first. Its high strength and deformation resistance ensure the overall structural stability of the assembly. Under the constraint of the stainless steel top cover sheet 22, the aluminum top cover sheet 21 will not deform in the middle position, thus avoiding the risk of cracking at the weld position.

[0053] In the description of this utility model, it should be understood that terms such as "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" 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 utility model 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 utility model.

[0054] 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 utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0055] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0056] Although the description of this utility model has been given in conjunction with the specific embodiments described above, it is obvious to those skilled in the art that many substitutions, modifications, and variations can be made based on the above description. Therefore, all such substitutions, modifications, and variations are included within the spirit and scope of the appended claims.

Claims

1. A high-strength top cover assembly, characterized in that, The device includes a composite top cover sheet, a lower plastic component, and an upper plastic component. The composite top cover sheet includes a stainless steel top cover sheet and an aluminum top cover sheet. The aluminum top cover sheet is stacked on the stainless steel top cover sheet, and the stainless steel top cover sheet is stacked on the lower plastic component. The aluminum top cover sheet has several openings, and the upper plastic component passes through the openings and is connected to the stainless steel top cover sheet.

2. The high-strength top cover assembly according to claim 1, characterized in that, The stainless steel top cover sheet has multiple thinning structures formed by stamping on its surface.

3. The high-strength top cover assembly according to claim 2, characterized in that, The thinning structure has a hexagonal honeycomb shape.

4. The high-strength top cover assembly according to claim 2, characterized in that, The aluminum top cover sheet has mounting bosses on all four sides, and the mounting bosses are pressed against the stainless steel top cover sheet.

5. The high-strength top cover assembly according to claim 1, characterized in that, A metal coating is provided at the interface between the stainless steel top cover and the aluminum top cover, and the metal coating has good compatibility with the stainless steel and aluminum.

6. The high-strength top cover assembly according to claim 1, characterized in that, The upper plastic assembly includes a positive electrode upper plastic and a negative electrode upper plastic, with a positive electrode aluminum block mounted on the positive electrode upper plastic and a negative electrode aluminum block mounted on the negative electrode upper plastic.

7. The high-strength top cover assembly according to claim 6, characterized in that, The positive electrode has a first groove on the plastic surface, and the negative electrode has a second groove on the plastic surface. The positive electrode aluminum block is embedded in the first groove, and the negative electrode aluminum block is embedded in the second groove.

8. The high-strength top cover assembly according to claim 6, characterized in that, It also includes a positive electrode post and a negative electrode post. One end of the positive electrode post passes through the lower plastic, the composite top cover, and the upper positive plastic and is riveted to the positive aluminum block. One end of the negative electrode post passes through the lower plastic, the composite top cover, and the upper negative plastic and is riveted to the negative aluminum block.

9. The high-strength top cover assembly according to claim 1, characterized in that, It also includes sealing rings, with two sealing rings respectively fitted onto the positive terminal and the negative terminal.

10. A battery, characterized in that, Including the high-strength top cover assembly as described in any one of claims 1 to 9 above.

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