Cylindrical steel shell battery cover plate structure and battery

Abstract

The utility model relates to a kind of cylindrical steel shell battery cover plate structure and battery, cylindrical steel shell battery cover plate structure includes cover plate body, copper pole, aluminum pole, strengthen sealing elastic ring, pressure relief safety valve and pressure relief valve protection piece;Copper pole is fixed in the center through-hole of cover plate body by PP rubber ring, realizes sealing insulation;Aluminum pole is located above copper pole, and strengthening sealing elastic ring is arranged between the two;Aluminum pole is deformed by pressurization to make elastic ring, and laser welding or riveting is used with copper pole fixed, so that elastic ring forms sealing surface under prestress;Pressure relief safety valve is connected with aluminum pole, and protection piece is attached to valve;The structure improves sealing reliability and security by multilayer sealing design.This utility model provides a kind of cylindrical steel shell battery cover plate structure and battery, by multigroup combination sealing design, aims at improving the sealing reliability and security of battery.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, and in particular to a cover plate structure for a cylindrical steel-cased lithium-ion battery and a battery including the cover plate structure. Background Technology

[0002] Cylindrical steel-cased lithium batteries are widely used due to their high degree of standardization, mature technology, and good structural strength. After the battery cell is installed in the steel casing, it needs to be sealed by a cover plate structure, and the positive and negative electrodes are led out. In the current mainstream cover plate structure, the connection and sealing between its core component—the nickel-plated copper electrode post—and the aluminum cover plate body is generally achieved by using PP adhesive (commonly known in the industry as "tab adhesive") through a hot-melt bonding process. This process requires that the PP adhesive can both firmly bond the electrode post and the cover plate and ensure electrical insulation between the two.

[0003] However, in practical applications, especially under complex operating conditions such as prolonged vibration, electrolyte immersion, and high and low temperature cycling, the single PP adhesive molten sealing structure faces challenges. Under the aforementioned stresses, the PP adhesive material may gradually age, creep, or become embrittled, leading to a decrease in its sealing performance and adhesive strength. This can result in risks such as battery leakage and insulation failure, affecting the reliability and lifespan of the battery.

[0004] Therefore, the industry needs a cylindrical battery cover structure with higher sealing reliability, longer service life, and better adaptability to complex application environments. Utility Model Content

[0005] In view of this, the present invention provides a cylindrical steel shell battery cover structure and battery, which aims to improve the sealing reliability and safety of the battery through a multi-combination sealing design.

[0006] The objective of this utility model is achieved through the following technical solution: A cylindrical steel-cased battery cover structure includes: a cover body, copper terminals, aluminum terminals, a reinforcing sealing elastic ring, a pressure relief safety valve, and a pressure relief valve protection plate. The cover body has a central through hole. The copper terminals are fixed to the central through hole of the cover body by a PP rubber ring through a melt-bonding process. The PP rubber ring provides sealing and insulation between the copper terminals and the cover body. The aluminum terminals are located on the side of the copper terminals away from the battery cell. The reinforcing sealing elastic ring is located between the copper terminals and the aluminum terminals. The pressure relief safety valve is connected to the aluminum terminals. The pressure relief valve protection plate is attached to the side of the pressure relief safety valve away from the battery cell. The aluminum terminals are elastically deformed by applying pressure to the reinforcing sealing elastic ring and are fixedly connected to the copper terminals by laser welding or riveting, thereby forming a sealing surface under prestress.

[0007] The core advantage lies in constructing a multi-layered, multi-mechanism synergistic composite sealing system, significantly improving the long-term reliability and safety of the battery. Firstly, through the molten composite process of the PP rubber ring, a first sealing and insulating barrier is formed between the copper electrode and the cover plate body. This barrier effectively prevents direct corrosion of the metal joints by the electrolyte and ensures the reliability of electrical insulation between the electrode and the casing. Secondly, an innovative "reinforced sealing elastic ring" and its matching aluminum electrode are introduced. By applying pressure and fixing it using laser welding or riveting, the elastic ring undergoes elastic deformation under continuous pre-stress, thus forming an extremely tight mechanical seal interface between the copper and aluminum electrode. This seal, as the second line of defense, is effective regardless of the adhesive properties of the colloid, thus effectively overcoming the inherent defects of traditional single PP rubber structures, which are prone to aging, embrittlement, and failure under long-term vibration, electrolyte immersion, and high / low temperature cycling conditions. The two sealing mechanisms complement each other. The first seal provides basic chemical stability and insulation, while the second mechanical seal provides a durable and stable physical compression seal, greatly reducing the risk of battery leakage due to seal failure at the terminals. Furthermore, the structure integrates a pressure relief safety valve and its protective plate, providing a controllable pressure relief channel for the battery under abnormal conditions, further enhancing the battery's safety protection level. This modular integrated design improves product performance while also giving the cover structure greater functionality and environmental adaptability.

[0008] Preferably, the sealing surface of the reinforced sealing elastic ring is provided with a first arc protrusion toward the cover plate body, or a second arc protrusion toward the aluminum pole, or both a first arc protrusion toward the cover plate body and a second arc protrusion toward the aluminum pole are provided.

[0009] The arc-shaped raised structure on the sealing surface, whether a single first or second arc-shaped raised section, or both sides simultaneously, offers the core advantage of achieving more efficient and reliable line contact or partial surface contact sealing. When pressure is applied to the aluminum electrode post, the first or second arc-shaped raised section preferentially undergoes elastic deformation. This design concentrates stress, generating sufficient contact pressure with relatively small pressing force, thereby quickly forming an effective sealing line. This contact method helps overcome potential leakage paths caused by microscopic unevenness of the sealing contact surface, improving the immediacy and consistency of the seal. Simultaneously, the arc-shaped raised design, compared to a purely flat or sharp-cornered design, has better stress distribution characteristics, reducing the risk of plastic deformation or stress cracking under long-term pressure, helping to maintain the long-term stability of the pre-pressure, thus extending the seal life. Offering multiple options such as first arc-shaped raised sections, second arc-shaped raised sections, or both sides also increases design flexibility, allowing it to adapt to battery designs with different internal spatial structures and assembly process requirements, expanding the application range of this technology.

[0010] Preferably, the outer diameter of the reinforcing sealing elastic ring is tapered.

[0011] The tapered outer diameter design allows the sealing ring to act as a guide and center during the pressing process into the corresponding inner hole of the cover plate body, simplifying the assembly process and facilitating automated production while improving assembly accuracy and efficiency. More importantly, the tapered structure naturally creates a progressive interference fit during pressing. As the pressing depth increases, a gradually increasing radial contact pressure is generated between the larger outer diameter end of the sealing ring and the mounting hole wall. This radial pressure causes slight radial elastic deformation of the sealing ring material, resulting in a tighter fit between its outer wall and the inner wall of the mounting hole. This is equivalent to adding an additional radial auxiliary sealing barrier on top of the axial seal. This barrier further prevents electrolyte from potentially seeping along the outer wall of the sealing ring, enhancing the redundancy of the seal and overall reliability. The tapered design also gives the sealing ring a self-tightening effect under internal pressure, helping to improve its sealing performance under complex operating conditions.

[0012] Preferably, the pressure relief port size of the pressure relief safety valve is configured to be adjustable according to the required pressure relief.

[0013] By designing the pressure relief valve's vent size to be configurable, the battery's pressure relief trigger pressure can be precisely set according to the specific safety standards and performance requirements of different customers and battery models. For example, batteries aiming for higher energy density may require earlier pressure relief to ensure absolute safety; while some high-power applications may require a higher trigger pressure. This adjustability allows manufacturers to use the same basic cover structure and quickly develop product lines that meet various technical specifications by changing the design of the pressure relief vent, significantly reducing mold development costs and production management complexity. Simultaneously, this also enables batteries to better adapt to future safety regulations and testing standards, enhancing the product's technological foresight and lifecycle.

[0014] Preferably, the cover plate body is made of aluminum alloy or SUS304 material.

[0015] Using aluminum alloy as the cover material offers several advantages. Firstly, aluminum alloy's low density helps reduce the overall weight of the battery, which is especially important for portable electronic devices. Secondly, aluminum alloy's good thermal conductivity allows heat generated during charging and discharging to dissipate more quickly through the cover, positively impacting thermal management. Furthermore, aluminum alloy has excellent machinability and relatively low cost. Using SUS304 stainless steel as an alternative choice offers the core advantages of its extremely high mechanical strength and excellent corrosion resistance. SUS304 material can better withstand the thermal and mechanical stresses generated during laser welding between the cover and the steel casing, ensuring a strong weld joint and a complete seal. It also has stronger resistance to electrolyte corrosion, making it particularly suitable for harsher applications or situations requiring extremely high long-term reliability. Offering these two material options gives battery manufacturers the flexibility to choose based on their process route (riveting or laser welding) and product positioning (cost or performance).

[0016] Preferably, a cylindrical steel-cased battery includes a steel casing, a battery cell, and a cover plate. The cover plate has the cylindrical steel-cased battery cover plate structure described above. A sealing ring is provided between the cover plate and the steel casing. The cover plate and the steel casing are sealed together by a riveting process. The riveting position of the steel casing undergoes plastic deformation, and the plastic deformation force is transmitted to the sealing ring, causing it to elastically deform and form a sealing surface.

[0017] Its core advantages lie in the multi-level sealing and mature technology achieved through the overall battery encapsulation. Using the cover plate structure described above, the sealing at the internal terminals of the battery has been reinforced through multiple enhancements, fundamentally reducing the risk of internal leakage. Furthermore, a separate sealing ring is used between the cover plate and the steel casing, employing a riveting process to create another independent external sealing barrier. The riveting process is a very mature, reliable, and cost-effective mechanical connection method. By plastically deforming the opening of the steel casing and pressing the sealing ring, the elastic recovery force of the sealing material forms a durable and reliable static seal. This seal primarily prevents moisture and dust from the external environment from entering the battery, while also preventing the escape of internal gases. The internal terminal seal and the external casing seal are independent yet complementary, together forming an extremely reliable battery encapsulation system, significantly improving the battery's sealing integrity and long-term reliability in various application environments.

[0018] Preferably, a cylindrical steel-cased battery includes a steel casing, a battery cell, and a cover plate, wherein the cover plate has the cylindrical steel-cased battery cover plate structure as described above; the cover plate and the steel casing are sealed together by laser welding, and the welded surfaces of the cover plate and the steel casing form a seal.

[0019] This is another battery packaging solution, offering advantages such as higher strength, higher sealing levels, and better space utilization. Using laser welding instead of traditional mechanical riveting creates a metallurgically bonded weld at the junction of the cover and the steel casing. This weld typically has a strength far exceeding that of the base material itself, resulting in a more rigid overall battery structure capable of withstanding higher internal pressure and stronger external mechanical impacts and vibrations, significantly improving the battery's mechanical safety performance. The seal formed by laser welding is a dense metallic seal, theoretically superior in terms of airtightness and liquid tightness to mechanical seals relying on elastic deformation. It can almost completely prevent the exchange of substances between the inside and outside, making it particularly suitable for applications with extremely stringent sealing requirements. Furthermore, laser welding is a non-contact, high-precision processing method with a small heat-affected zone and minimal deformation, helping to maintain the battery's appearance quality and dimensional accuracy. Simultaneously, it eliminates the need for flanging structures that might be required in riveting processes, thus improving the battery's volumetric energy density.

[0020] Preferably, a method for preparing a cylindrical steel-cased battery cover structure as described above includes the following steps: S1: Copper terminals and a cover body with a central through hole are composite molded using a PP rubber ring through a melt-bonding process to form a first component, wherein the PP rubber ring provides sealing and insulation; S2: A reinforcing sealing elastic ring is placed on the copper terminals of the first component; S3: An aluminum terminal is assembled into place and pressure is applied to it, causing the reinforcing sealing elastic ring to undergo elastic deformation under stress; S4: The copper terminal and the aluminum terminal are fixedly connected using laser welding or riveting to form a second component; S5: A pressure relief safety valve is welded to the aluminum terminal of the second component to form a third component; S6: A pressure relief valve protective plate is bonded to the third component to form a complete battery cover.

[0021] The advantage of this preparation method lies in defining a clear, highly operable assembly process that ensures high product performance and consistency. This method employs a step-by-step assembly and hierarchical integration strategy, breaking down the complex multi-layered structure into several simple processes, which facilitates automated production and precise quality control. Step S1 first reliably solves the basic electrical insulation and initial sealing issues through a mature melt-bonding process, providing a reliable foundation for subsequent component installation. Steps S2 to S4 are crucial for forming the core mechanical seal: first, the elastic ring is placed; then, pressure is applied to pre-deform it to the designed state; finally, this state is permanently locked using laser welding or riveting. This sequence ensures that the sealing ring is always in an optimal pre-stress state, thereby guaranteeing the uniformity and stability of the final product's sealing performance. The choice between laser welding or riveting processes provides flexibility and enables the formation of high-strength, high-reliability mechanical connections. Subsequent steps S5 and S6 integrate safety function modules, completing the final product assembly. The entire method has a rigorous logical flow, with each step laying the foundation for the next, ultimately ensuring the realization of the excellent performance of the cover plate structure.

[0022] Preferably, in step S5, the size of the pressure relief port of the pressure relief safety valve is determined based on the material yield strength and the target pressure relief pressure.

[0023] This approach directly links the design of the pressure relief valve, a critical safety component, to materials science and engineering goals, emphasizing a precise design method based on scientific calculations, rather than relying on experience or trial and error. The core function of the pressure relief valve is timely activation under specific pressures, with its trigger pressure primarily depending on the valve body's structure (especially the size of the weakest point, the pressure relief port) and the material's mechanical properties (such as yield strength). This method explicitly requires working backward from the actual yield strength of the selected material and the target pressure relief pressure required by the product design to determine the precise dimensions of the pressure relief port. This physics-based design method significantly improves the consistency, accuracy, and reliability of the pressure relief valve's activation pressure, reducing performance fluctuations caused by manufacturing tolerances or batch variations in materials. It ensures that each batch of pressure relief valves opens precisely within a preset safety threshold, thereby greatly enhancing the reliability and consistency of battery safety protection functions and meeting the stringent requirements of high-end application markets for battery safety performance.

[0024] The advantages of this utility model compared to the prior art are: 1. Multiple composite seals enhance reliability: The cover structure of this utility model employs at least two core sealing mechanisms. The first is a molten composite seal provided by a PP rubber ring, primarily responsible for insulation and initial sealing. The second is a mechanical seal composed of a pre-compressed reinforced sealing elastic ring. These two seals work together and serve as backups for each other. Even when the performance of the PP rubber deteriorates due to long-term aging, the mechanical seal can still function effectively, thereby significantly reducing the risk of battery leakage and improving the long-term reliability of the battery under harsh operating conditions.

[0025] 2. Diverse material and process options, flexible application: The cover plate body can be made of different materials such as aluminum alloy or stainless steel (e.g., SUS304), allowing it to adapt to both riveting and laser welding processes for casing sealing. This provides battery manufacturers with greater design flexibility and process selection space, enabling them to choose the optimal solution based on product positioning and production line configuration.

[0026] 3. Enhanced Safety: An integrated safety valve structure with adjustable pressure relief provides crucial safety protection for the battery. The size of the pressure relief port can be adjusted based on material strength and target pressure to meet different safety standards.

[0027] 4. Structural design optimization: The design of the arc protrusion and tapered shape on the sealing elastic ring helps to form a more effective line seal or surface seal during assembly, improves stress distribution, and makes the assembly process smoother, which is conducive to improving production yield and consistency. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a structural diagram of the cylindrical steel shell battery cover structure of Embodiment 1 of this utility model.

[0030] Figure 2 This is a structural diagram of the cylindrical steel shell battery cover structure of Embodiment 2 of this utility model.

[0031] Figure 3 This is a structural diagram of the cylindrical steel shell battery cover structure of Embodiment 3 of this utility model.

[0032] Labeling Explanation: 1. Cover plate body, 2. Copper pole, 3. PP rubber ring, 4. Aluminum pole, 5. Reinforced sealing elastic ring, 51. First arc protrusion, 52. Second arc protrusion, 6. Pressure relief safety valve, 61. Pressure relief port, 7. Pressure relief valve protective plate. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0035] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of the embodiments of this application, it should be understood that the terms "upper," "lower," "left," "right," "vertical," "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship commonly used when the product of this application is in use, or the orientation or positional relationship commonly understood by those skilled in the art. 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.

[0036] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0037] The technical solutions in this application will now be described with reference to the accompanying drawings. Example

[0038] This embodiment provides a cylindrical steel-cased battery cover structure, including: a cover body 1 with a central through hole; a copper electrode 2, which is fixed in the central through hole of the cover body 1 by a PP rubber ring 3 through a melt-bonding process, the PP rubber ring 3 achieving sealing and insulation between the copper electrode 2 and the cover body 1; an aluminum electrode 4, which is disposed on the side of the copper electrode 2 away from the battery cell; a reinforcing sealing elastic ring 5, which is disposed between the copper electrode 2 and the aluminum electrode 4; a pressure relief safety valve 6, which is connected to the aluminum electrode 4; and a pressure relief valve protection plate 7, which is attached to the side of the pressure relief safety valve 6 away from the battery cell; wherein, the aluminum electrode 4 undergoes elastic deformation by applying pressure to the reinforcing sealing elastic ring 5, and is fixedly connected to the copper electrode 2 by laser welding or riveting process, thereby forming a sealing surface under prestress of the reinforcing sealing elastic ring 5.

[0039] The core advantage lies in constructing a multi-layered, multi-mechanism synergistic composite sealing system, significantly improving the long-term reliability and safety of the battery. Firstly, through the molten composite process of the PP rubber ring 3, a first sealing and insulating barrier is formed between the copper electrode post 2 and the cover plate body 1. This barrier effectively prevents direct corrosion of the metal joint by the electrolyte and ensures the reliability of electrical insulation between the electrode post and the casing. Secondly, an innovative "reinforced sealing elastic ring 5" and its matching aluminum electrode post 4 are introduced. By applying pressure and fixing it using laser welding or riveting, the elastic ring undergoes elastic deformation under continuous pre-stress, thus forming an extremely tight mechanical sealing interface between the copper electrode post 2 and the aluminum electrode post 4. This seal, as the second line of defense, is effective regardless of the adhesive properties of the colloid, thus effectively overcoming the inherent defects of traditional single PP rubber structures, such as easy aging, embrittlement, and failure under long-term vibration, electrolyte immersion, and high and low temperature cycling conditions. The two sealing mechanisms complement each other. The first seal provides basic chemical stability and insulation, while the second mechanical seal provides a durable and stable physical compression seal, greatly reducing the risk of battery leakage due to seal failure at the terminals. Furthermore, the structure integrates a pressure relief safety valve 6 and its protective plate 7, providing a controllable pressure relief channel for the battery under abnormal conditions, further enhancing the battery's safety protection level. This modular integrated design improves product performance while also giving the cover structure greater functionality and environmental adaptability.

[0040] The PP sealing ring 3 is made of polypropylene (PP) or modified from it. This material was chosen based on its high compatibility with the lithium-ion battery application environment: First, polypropylene exhibits excellent corrosion resistance and low swelling rate against common organic electrolytes (such as carbonate solvents) found inside batteries, maintaining dimensional stability and sealing integrity over a long period, preventing seal failure due to material degradation. Second, polypropylene has good electrical insulation properties, reliably ensuring electrical isolation between the copper electrode post 2 and the aluminum alloy or stainless steel cover plate body 1, preventing short circuits. Finally, as a thermoplastic material, polypropylene can form a dense and robust weld interface with metal parts (copper electrode post and cover plate body) through a melt-bonding process under specific temperature and pressure, achieving integrated structural bonding and sealing. Therefore, the PP sealing ring 3 is not an ordinary sealing ring, but a key component integrating multiple functions such as insulation, structural bonding, and primary sealing. Its material properties are the foundation for the effective operation of the mechanical seal constructed by the subsequent reinforcing sealing elastic ring 5.

[0041] In this embodiment, the sealing surface of the reinforcing sealing elastic ring 5 is simultaneously provided with a first arcuate protrusion 51 facing the cover plate body 1 and a second arcuate protrusion 52 facing the aluminum pole post 4.

[0042] The arc-shaped raised structure on the sealing surface offers the key advantage of achieving more efficient and reliable line contact or partial surface contact sealing. When pressure is applied to the aluminum pole 4, the first arc-shaped raised section 51 or the second arc-shaped raised section 52 preferentially undergoes elastic deformation. This design concentrates stress, generating sufficient contact pressure with relatively small pressing force, thereby quickly forming an effective sealing line. This contact method helps overcome potential leakage paths caused by microscopic unevenness of the sealing contact surface, improving the immediacy and consistency of the seal. Simultaneously, compared to purely flat or sharp-angled designs, the arc-shaped raised design has better stress distribution characteristics, reducing the risk of plastic deformation or stress cracking under long-term pressure, helping to maintain the long-term stability of the pre-pressure, and thus extending the seal life.

[0043] In this embodiment, the outer diameter of the reinforcing sealing elastic ring 5 is tapered.

[0044] The tapered outer diameter design allows the sealing ring to act as a guide and center during the pressing process into the corresponding inner hole of the cover plate body 1, simplifying the assembly process and facilitating automated production while improving assembly accuracy and efficiency. More importantly, the tapered structure naturally creates a progressive interference fit during pressing. As the pressing depth increases, a gradually increasing radial contact pressure is generated between the larger outer diameter end of the sealing ring and the mounting hole wall. This radial pressure causes slight radial elastic deformation of the sealing ring material, resulting in a tighter fit between its outer wall and the inner wall of the mounting hole. This is equivalent to adding an additional radial auxiliary sealing barrier in addition to the axial seal. This barrier further prevents the electrolyte from potentially seeping along the outer wall of the sealing ring, enhancing the redundancy of the seal and overall reliability. The tapered design also gives the sealing ring a self-tightening effect when subjected to internal pressure, helping to improve its sealing performance under complex operating conditions.

[0045] In this embodiment, the size of the pressure relief port 61 of the pressure relief safety valve 6 is configured to be adjustable according to the required pressure relief.

[0046] By making the pressure relief port 61 of the pressure relief safety valve 6 configurable, the battery's pressure relief trigger pressure can be precisely set according to the specific safety standards and performance requirements of different customers and battery models. For example, for batteries pursuing higher energy density, earlier pressure relief may be required to ensure absolute safety; while for some high-power applications, a higher trigger pressure may be set. This adjustability allows manufacturers to use the same basic cover structure 1 and quickly develop product lines that meet various technical specifications by changing the design of the pressure relief port 61, significantly reducing mold development costs and production management complexity. At the same time, this also enables batteries to better adapt to future updated safety regulations and testing standards, improving the forward-looking nature and lifecycle of the product technology roadmap.

[0047] In this embodiment, the cover plate body 1 is made of aluminum alloy or SUS304 material.

[0048] Using aluminum alloy as the cover material has advantages such as low density, which helps reduce the overall weight of the battery, especially important for portable electronic devices. Aluminum alloy also has good thermal conductivity, allowing heat generated during charging and discharging to dissipate more quickly through the cover, positively impacting thermal management. Furthermore, aluminum alloy has excellent machinability and relatively low cost. Alternatively, using SUS304 stainless steel offers the core advantages of its extremely high mechanical strength and excellent corrosion resistance. SUS304 material can better withstand the thermal and mechanical stresses generated during laser welding between the cover and the steel shell, ensuring a strong weld joint and a complete seal. It also has stronger resistance to electrolyte corrosion, making it particularly suitable for harsher applications or situations requiring extremely high long-term reliability. Offering these two material options gives battery manufacturers the flexibility to choose based on their process route (riveting or laser welding) and product positioning (cost or performance). Example

[0049] Compared to Embodiment 1, in this embodiment, the sealing surface of the reinforced sealing elastic ring 5 is provided with a first arcuate protrusion 51 facing the cover plate body 1.

[0050] The arc-shaped raised structure on the sealing surface offers the key advantage of achieving more efficient and reliable line contact or partial surface contact sealing. When pressure is applied to the aluminum pole 4, the first arc-shaped raised section 51 preferentially undergoes elastic deformation. This design concentrates stress, generating sufficient contact pressure with relatively small pressing force, thereby quickly forming an effective sealing line. This contact method helps overcome potential leakage paths caused by microscopic unevenness of the sealing contact surface, improving the immediacy and consistency of the seal. Simultaneously, compared to purely flat or sharp-angled designs, the arc-shaped raised design has better stress distribution characteristics, reducing the risk of plastic deformation or stress cracking under long-term pressure, helping to maintain the long-term stability of the pre-pressure, and thus extending the seal life. Example

[0051] Compared to Example 1, in this example, the sealing surface of the reinforced sealing elastic ring 5 is provided with a second arc protrusion 52 facing the aluminum pole post 4.

[0052] The arc-shaped raised structure on the sealing surface offers the key advantage of achieving more efficient and reliable line contact or partial surface contact sealing. When pressure is applied to the aluminum pole 4, the second arc-shaped raised section 52 preferentially undergoes elastic deformation. This design concentrates stress, generating sufficient contact pressure with relatively small pressing force, thereby quickly forming an effective sealing line. This contact method helps overcome potential leakage paths caused by microscopic unevenness of the sealing contact surface, improving the immediacy and consistency of the seal. Simultaneously, compared to purely flat or sharp-angled designs, the arc-shaped raised design has better stress distribution characteristics, reducing the risk of plastic deformation or stress cracking under long-term pressure, helping to maintain the long-term stability of the pre-pressure, and thus extending the seal life. Example

[0053] In this embodiment, a cylindrical steel-cased battery includes a steel casing, a battery cell, and a cover plate. The cover plate is a cylindrical steel-cased battery cover plate structure as described in Embodiment 1, 2, or 3. A sealing ring is provided between the cover plate and the steel casing. The cover plate and the steel casing are connected in a sealed manner through a riveting process. In this process, the riveting position of the steel casing undergoes plastic deformation, and the plastic deformation force is transmitted to the sealing ring to cause it to elastically deform, forming a sealing surface.

[0054] Its core advantage lies in achieving multi-level sealing and technological maturity in the overall battery encapsulation. Using the cover plate structure 1 described above, the sealing at the internal terminals of the battery has been strengthened through the aforementioned multiple enhancements, fundamentally reducing the risk of internal leakage. Furthermore, a separate sealing ring is used between the cover plate and the steel casing, and a riveting process is employed for encapsulation, constructing another independent external sealing barrier. The riveting process is a very mature, reliable, and cost-effective mechanical connection method. By plastically deforming the opening of the steel casing and pressing the sealing ring, the elastic recovery force of the sealing material is utilized to form a durable and reliable static seal. This seal primarily... Its main function is to prevent moisture, dust, and other external environmental contaminants from entering the battery, while also preventing the escape of internal gases. The internal terminal seal and the external casing seal are independent yet complementary, together forming an extremely reliable battery packaging system that significantly improves the battery's sealing integrity and long-term reliability in various application environments.

[0055] In this embodiment, when the riveting process is used, the riveting position of the steel shell undergoes plastic deformation, and the plastic deformation force is transmitted to the sealing ring to cause it to elastically deform and form a sealing surface.

[0056] The advantages lie in clearly defining the transmission path of the sealing force and the essence of seal formation, highlighting the reliability and adaptability of this sealing method. This feature emphasizes that seal formation does not rely on additional fasteners or adhesives, but cleverly utilizes the plastic deformation of the steel shell material as the power source. The force applied by the riveting tool causes permanent deformation at the opening of the steel shell. This deformation process continuously compresses the elastic sealing ring located between the cover plate and the steel shell. After compression, the sealing ring undergoes elastic deformation, and its rebound force acts evenly on the contact surface between the cover plate and the steel shell, filling all microscopic unevenness, thus forming a continuous and stable sealing interface. This sealing method has a certain tolerance for part machining accuracy and assembly errors. As long as sufficient compression is ensured, effective sealing can be achieved, demonstrating good process robustness. The seal based on elastomer deformation also has a certain compensatory effect, maintaining an effective sealing state even when the pre-pressure slightly relaxes due to vibration or temperature changes during long-term use. Example

[0057] In this embodiment, a cylindrical steel-cased battery includes a steel casing, a battery cell, and a cover plate. The cover plate is a cylindrical steel-cased battery cover plate structure as described in Embodiment 1, 2, or 3. The cover plate and the steel casing are sealed together by laser welding, and the welded surfaces of the cover plate and the steel casing form a seal.

[0058] This is another battery packaging solution, offering advantages such as higher strength, higher sealing levels, and better space utilization. Using laser welding instead of traditional mechanical riveting creates a metallurgically bonded weld at the junction of the cover and the steel casing. This weld typically has a strength far exceeding that of the base material itself, resulting in a more rigid overall battery structure capable of withstanding higher internal pressure and stronger external mechanical impacts and vibrations, significantly improving the battery's mechanical safety performance. The seal formed by laser welding is a dense metallic seal, theoretically superior in terms of airtightness and liquid tightness to mechanical seals relying on elastic deformation. It can almost completely prevent the exchange of substances between the inside and outside, making it particularly suitable for applications with extremely stringent sealing requirements. Furthermore, laser welding is a non-contact, high-precision processing method with a small heat-affected zone and minimal deformation, helping to maintain the battery's appearance quality and dimensional accuracy. Simultaneously, it eliminates the need for flanging structures that might be required in riveting processes, thus improving the battery's volumetric energy density. Example

[0059] In this embodiment, a method for preparing a cylindrical steel-cased battery cover structure as described in Embodiments 1, 2, or 3 includes the following steps: S1: Copper electrode 2 and cover body 1 with a central through hole are composite molded using a PP rubber ring 3 through a melt composite process to form a first component, where the PP rubber ring 3 provides sealing and insulation; S2: A reinforcing sealing elastic ring 5 is placed on the copper electrode 2 of the first component; S3: Aluminum electrode 4 is assembled into place and pressure is applied to it, causing the reinforcing sealing elastic ring 5 to undergo elastic deformation under stress; S4: The copper electrode 2 and aluminum electrode 4 are fixedly connected using laser welding or riveting to form a second component; S5: A pressure relief safety valve 6 is welded to the aluminum electrode 4 of the second component to form a third component; S6: A pressure relief valve protection plate 7 is bonded to the third component to form a complete battery cover.

[0060] The advantage of this preparation method lies in defining a clear, highly operable assembly process that ensures high product performance and consistency. This method employs a step-by-step assembly and hierarchical integration strategy, breaking down the complex multi-layered structure into several simple processes, which facilitates automated production and precise quality control. Step S1 first reliably solves the basic electrical insulation and initial sealing issues through a mature melt-bonding process, providing a reliable foundation for subsequent component installation. Steps S2 to S4 are crucial for forming the core mechanical seal: first, the elastic ring is placed; then, pressure is applied to pre-deform it to the designed state; finally, this state is permanently locked using laser welding or riveting. This sequence ensures that the sealing ring is always in an optimal pre-stress state, thereby guaranteeing the uniformity and stability of the final product's sealing performance. The choice between laser welding or riveting processes provides flexibility and enables the formation of high-strength, high-reliability mechanical connections. Subsequent steps S5 and S6 integrate safety function modules, completing the final product assembly. The entire method has a rigorous logical flow, with each step laying the foundation for the next, ultimately ensuring the realization of the excellent performance of the cover structure 1.

[0061] In this embodiment, in step S5, the size of the pressure relief port 61 of the pressure relief safety valve 6 is determined based on the material yield strength and the target pressure relief pressure.

[0062] This design approach directly links the pressure relief valve, a critical safety component, to materials science and engineering goals, emphasizing a precise design method based on scientific calculations rather than relying on experience or trial and error. The core function of the pressure relief safety valve 6 is to actuate promptly under specific pressures. Its trigger pressure depends primarily on the valve body structure (especially the size of the weakest point, the pressure relief port 61) and the mechanical properties of the material (such as yield strength). This method explicitly requires back-calculating and determining the precise size of the pressure relief port 61 based on the actual yield strength of the selected material and the target pressure relief required by the product design. This physics-based design method significantly improves the consistency, accuracy, and reliability of the pressure relief valve's actuation pressure, reducing performance fluctuations caused by manufacturing tolerances or batch variations in materials. It ensures that each batch of pressure relief safety valves 6 can open precisely within a preset safety threshold, thereby greatly enhancing the reliability and consistency of battery safety protection functions and meeting the stringent requirements of high-end application markets for battery safety performance.

[0063] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A cylindrical steel-cased battery cover structure, characterized in that, include: Cover plate body (1) with a central through hole; The copper electrode post (2) is fixed in the central through hole of the cover plate body (1) by a PP rubber ring (3) through a melt composite process. The PP rubber ring (3) achieves sealing and insulation between the copper electrode post (2) and the cover plate body (1). An aluminum electrode post (4) is disposed on the side of the copper electrode post (2) away from the battery cell; A reinforced sealing elastic ring (5) is disposed between the copper electrode post (2) and the aluminum electrode post (4); A pressure relief safety valve (6) is connected to the aluminum pole (4); and Pressure relief valve protection plate (7), which is attached to the side of the pressure relief safety valve (6) away from the battery cell; The aluminum pole (4) is subjected to pressure on the reinforcing sealing elastic ring (5) to cause it to deform elastically, and is fixedly connected to the copper pole (2) by laser welding or riveting process, so that the reinforcing sealing elastic ring (5) forms a sealing surface under prestress.

2. The cylindrical steel shell battery cover structure according to claim 1, characterized in that, The sealing surface of the reinforced sealing elastic ring (5) is provided with a first arc protrusion (51) facing the cover plate body (1) or a second arc protrusion (52) facing the aluminum pole (4), or both a first arc protrusion (51) facing the cover plate body (1) and a second arc protrusion (52) facing the aluminum pole (4) are provided.

3. The cylindrical steel-cased battery cover structure according to claim 1 or 2, characterized in that, The outer diameter of the reinforced sealing elastic ring (5) is tapered.

4. The cylindrical steel-cased battery cover structure according to claim 1, characterized in that, The pressure relief port (61) of the pressure relief safety valve (6) is configured to be adjustable according to the required pressure relief.

5. The cylindrical steel-cased battery cover structure according to claim 1, characterized in that, The cover plate body (1) is made of aluminum alloy or SUS304 material.

6. A cylindrical steel-cased battery, comprising a steel casing, a battery cell, and a cover plate, characterized in that, The cover plate is the cylindrical steel shell battery cover plate structure as described in any one of claims 1 to 5; A sealing ring is provided between the cover plate and the steel shell; The cover plate and the steel shell are sealed together by riveting. The riveting position of the steel shell undergoes plastic deformation, and the plastic deformation force is transmitted to the sealing ring, causing it to elastically deform and form a sealing surface.

7. A cylindrical steel-cased battery, comprising a steel casing, a battery cell, and a cover plate, characterized in that, The cover plate is the cylindrical steel shell battery cover plate structure as described in any one of claims 1 to 5; The cover plate and the steel shell are sealed together by laser welding, and the welded surfaces of the cover plate and the steel shell form a seal.

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