Resistance-welded aluminum shell cylindrical battery cover plate

Abstract

The application relates to the technical field of battery end covers, and discloses a resistance-welded aluminum shell cylindrical battery cover plate which comprises a busbar, an inner insulating pad, an aluminum cover, an outer insulating pad, a pole and a rivet assembly. The busbar, the inner insulating pad, the aluminum cover, the outer insulating pad and the pole assembly are all provided with riveting holes. The rivet passes through the riveting hole of the busbar and is ultrasonically welded together to form a cover plate component. The cover plate component formed by ultrasonically welding the busbar and the rivet is riveted together with the inner insulating pad, the aluminum cover, the outer insulating pad and the pole to form a cover plate. The inner insulating pad and the aluminum cover are provided with sealing rings in the interior of the riveting holes. The busbar comprises a busbar part, a fuse part and a connecting part. The fuse part is provided with a protection assembly in the middle. The aluminum shell cylindrical battery can be connected in modules by using a resistance welding process, thereby overcoming the limitation that the traditional aluminum cover plate can only be laser welded. The resistance welding equipment has low investment cost and simple process, and is helpful to greatly reduce the production threshold and manufacturing cost.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of battery end covers, in particular to a resistance-welded aluminum shell cylindrical battery cover plate. BACKGROUND

[0002] Cylindrical lithium batteries are mainly divided into steel shell cylindrical batteries and aluminum shell cylindrical batteries according to the different shell materials. The steel shell cylindrical battery usually adopts a resistance welding process in the module assembly process. The process is simple, and the equipment investment cost is low, so it is widely used in the fields of household energy storage, portable energy storage, low-speed two-wheeled vehicles, three-wheeled vehicles and electric vehicles. The aluminum shell cylindrical battery is generally equipped with an aluminum cover plate, and a laser welding process is usually used in the module assembly. The laser welding equipment investment is large, the process complexity is high, and the yield is easily affected by factors such as material flatness, impurity content and welding power, and yield fluctuation is prone to occur.

[0003] In order to adapt to the needs of different customers for welding processes, it is particularly important to develop an aluminum shell cylindrical battery cover plate suitable for resistance welding. The common aluminum shell cylindrical battery cover plate currently available has an aluminum pole, which can only be laser welded and cannot be resistance welded. Since the resistance welding process is simple and the equipment cost is low, it is still dominant in the markets of two-wheeled electric vehicles, three-wheeled electric vehicles and portable energy storage, etc. Therefore, the introduction of an aluminum shell cylindrical battery cover plate that can be resistance welded not only helps to meet the diversified market demand, but also reduces the equipment investment cost.

[0004] In addition, during the charging and discharging process of the battery, explosion or fire may occur due to abnormal conditions such as current overload, and the like. Usually, a fuse structure is arranged on the bus bar to quickly melt and cut off the circuit when the internal pressure of the battery cell or the current abnormally rises. However, the fuse structure of the existing bus bar is often in a bent state when connected with the tab and the top cover. This state may cause the fuse to stick at the breakage after melting, so that the circuit remains conductive, thereby causing the fuse to fail and failing to achieve the desired safety protection function.

[0005] Therefore, we have improved it and proposed a resistance-welded aluminum shell cylindrical battery cover plate. SUMMARY

[0006] The purpose of the present application is to provide a resistance-welded aluminum shell cylindrical battery cover plate to solve the problems raised in the background art.

[0007] In order to achieve the above-mentioned purposes, the application provides a cylindrical battery cover plate of resistance-welded aluminum shell, which comprises a busbar, an inner insulating pad, an aluminum cover, an outer insulating pad, a pole and a rivet assembly, the busbar, the inner insulating pad, the aluminum cover, the outer insulating pad and the pole assembly are provided with riveting holes, the rivet passes through the riveting hole of the busbar, and the busbar and the rivet are ultrasonically welded together to form a cover plate component; the cover plate component formed by ultrasonic welding of the busbar and the rivet is riveted with the inner insulating pad, the aluminum cover, the outer insulating pad and the pole to form a cover plate; the inner insulating pad and the aluminum cover are provided with sealing rings inside the riveting holes; the busbar comprises a busbar part, a fuse part and a connecting part, and the middle part of the fuse part is connected with a protection assembly.

[0008] As a further scheme of the application, the inner insulating pad comprises a pad, the upper end surface of the pad is provided with a hollow hole, the upper end of the hole of the riveting hole of the pad is expanded to form a receiving hole, the sealing ring is embedded at the connection between the receiving hole and the aluminum cover to insulate the rivet and the aluminum cover, the bottom surface of the pad is fixedly installed with a step, and the upper end surface of the pad is provided with a circular boss.

[0009] As a further scheme of the application, the aluminum cover comprises a cover sheet, one side of the upper end surface of the cover sheet is fixedly installed with a two-dimensional code, the bottom surface of the cover sheet is protrusively installed with a liquid injection hole, the liquid injection hole is embedded in the hollow hole, the bottom surface of the cover sheet is provided with a circular positioning hole, the lower concave hole of the circular positioning hole is consistent in size with the circular boss, the inner insulating pad and the aluminum cover are embedded and installed through the circular positioning hole and the circular boss during assembly of the cover plate, and the inner insulating pad and the aluminum cover are accurately positioned.

[0010] As a further scheme of the application, the upper end surface of the outer insulating pad is provided with a lower concave groove, the depth of the groove is consistent with the height of the pole, and the upper surfaces of the outer insulating pad and the pole are flush after assembly.

[0011] As a further scheme of the application, the pole comprises an aluminum core, the upper end surface of the aluminum core is provided with an aluminum layer, the lower end of the aluminum core is provided with a composite layer, the aluminum layer, the aluminum core and the composite layer are integrally formed by pressing, a connecting rod is rotatably sleeved in the middle of the aluminum core, and the bottom of the connecting rod is fixedly connected to the outer insulating pad.

[0012] As a further scheme of the application, the aluminum core is an aluminum plate, the aluminum layer is an aluminum strip, and the composite layer is one of a nickel layer and an aluminum-nickel composite strip; when the composite layer is the nickel layer, the thickness of the nickel layer is 1mm to 5mm; when the composite layer is the aluminum-nickel composite strip, the nickel layer faces outward and is an electric resistance welding surface, and the thickness of the nickel layer is 1mm to 5mm, wherein the thickness of the nickel layer is 0.1mm to 4.9mm.

[0013] As a further embodiment of the present invention, the protective component includes a support frame, which is welded and fixedly installed on the bottom surface of the inner insulating pad. Two pressure plates are symmetrically and movably installed at both ends of the support frame. One end of the pressure plate is connected to a tension spring, the upper end of which is welded and fixed to the inner insulating pad. The other end of the pressure plate is connected to a temperature control spring, the bottom end of which is welded and fixed to the busbar.

[0014] As a further embodiment of the present invention, the compression ratio of the sealing ring during the riveting process controlled by the receiving hole is between 15% and 35%.

[0015] The beneficial effects of the resistance-welded aluminum-cased cylindrical battery cover provided by this invention are:

[0016] 1. Aluminum-cased cylindrical batteries can be connected in modules using resistance welding, overcoming the limitations of traditional aluminum cover plates which can only be laser welded. Resistance welding equipment has low investment costs and simple processes, which helps to significantly reduce production thresholds and manufacturing costs. The inner insulating pad and the aluminum cover adopt a matching design of circular boss and circular positioning hole, which realizes rapid and accurate positioning between components, improves assembly efficiency and consistency. The sealing ring is placed in a specially designed receiving hole, and by controlling the riveting compression ratio (15%-35%), the excellent sealing effect at the riveting hole is scientifically guaranteed, effectively avoiding the risk of battery leakage. The coordinated design of the inner and outer insulating pads ensures reliable insulation between the terminal post and the aluminum cover (battery shell), ensuring the normal operation of the battery. The cover plate integrates standard functions such as injection hole and QR code identification, meeting the needs of the entire battery production and traceability process.

[0017] 2. By adopting a multi-layer composite structure for the pole, compatibility and conductivity with the internal structure are ensured. At the same time, the connection in the middle of the pole can be flipped to connect to the internal structure, allowing for selection of welding methods during welding. The aluminum layer on the upper end and the composite layer on the lower end provide external welding interfaces suitable for different welding modes. After rotation, resistance welding or laser welding processes can be selected for welding to meet the welding process requirements of different customers. Press-fitting ensures the stability and conductivity of the structure.

[0018] 3. By installing protective components on the fuse section, the support frame and pressure plate press on the bent fuse section to position it and prevent overlap after bending. The pressure plate is equipped with tension springs and temperature control springs at both ends. The tension springs and temperature control springs pull the pressure plate to ensure that the pressure plate remains parallel to the aluminum cover. When the internal pressure or current of the battery cell rises abnormally, the heat generated will also change the characteristics of the temperature control spring (such as losing elasticity), disrupting the original balance. Under the tension of the tension spring, the pressure plate will swing downward rapidly, impacting or pulling the fuse section that is about to melt or has just melted, thereby physically breaking any possible molten metal adhesion, ensuring that the circuit is completely disconnected, and effectively preventing fuse failure. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This application provides a structural schematic diagram of a resistance-welded aluminum-cased cylindrical battery cover plate.

[0021] Figure 2 A bottom view of the structure of a resistance-welded aluminum-cased cylindrical battery cover provided in this application;

[0022] Figure 3 A top view of the structure of a resistance-welded aluminum-cased cylindrical battery cover provided in this application;

[0023] Figure 4 An exploded view of the structure of a resistance-welded aluminum-cased cylindrical battery cover plate provided in this application;

[0024] Figure 5 A schematic diagram of the bending of the busbar structure of a resistance-welded aluminum shell cylindrical battery cover plate provided in this application;

[0025] Figure 6 A schematic diagram of the inner insulating pad structure of a resistance-welded aluminum-cased cylindrical battery cover provided in this application;

[0026] Figure 7 A schematic diagram of the aluminum cover structure of a resistance-welded cylindrical battery cover provided in this application. Figure 1 ;

[0027] Figure 8 A schematic diagram of the aluminum cover structure of a resistance-welded cylindrical battery cover provided in this application. Figure 2 ;

[0028] Figure 9 A schematic diagram of the electrode structure of a resistance-welded aluminum-cased cylindrical battery cover plate provided in this application;

[0029] Figure 10 A schematic diagram of a protective component structure for a resistance-welded aluminum-cased cylindrical battery cover provided in this application;

[0030] Figure 11 This application provides a schematic diagram of the aluminum core and connecting rod connection of a resistance-welded aluminum shell cylindrical battery cover.

[0031] In the diagram: 1. Busbar; 11. Busbar section; 12. Fusible link; 13. Connecting part; 2. Inner insulating pad; 21. Gasket; 22. Clearance hole; 23. Circular boss; 24. Step; 25. Receiving hole; 3. Aluminum cover; 31. Cover plate; 32. Circular positioning hole; 33. Injection hole; 34. QR code; 4. Outer insulating pad; 5. Terminal post; 51. Aluminum core; 52. Aluminum layer; 53. Composite layer; 54. Connecting rod; 6. Sealing ring; 7. Rivet; 8. Protective component; 81. Support frame; 82. Pressure plate; 83. Tension spring; 84. Temperature control spring; 9. Riveting hole. Detailed Implementation

[0032] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0033] like Figures 1-11 As shown, this embodiment proposes a resistance-welded aluminum-cased cylindrical battery cover plate, including a busbar 1, an inner insulating pad 2, an aluminum cover 3, an outer insulating pad 4, a terminal post 5, and a rivet 7 assembly. The busbar 1, inner insulating pad 2, aluminum cover 3, outer insulating pad 4, and terminal post 5 assembly all have riveting holes 9. The rivets 7 pass through the riveting holes 9 in the busbar 1 and are ultrasonically welded together to form a cover plate component. The cover plate component formed by ultrasonically welding the busbar 1 and rivets 7 is riveted together with the inner insulating pad 2, aluminum cover 3, outer insulating pad 4, and terminal post 5 to form a cover. A sealing ring 6 is provided inside the riveting hole 9 on the plate, the inner insulating pad 2 and the aluminum cover 3. The busbar 1 includes a busbar part 11, a fuse part 12 and a connecting part 13. A protective component 8 is connected to the middle of the fuse part 12. The busbar 1 is a key component for the collection and conduction of current inside the battery. Its busbar part 11 is used to connect with the battery tab. The fuse part 12 melts in case of overcurrent or overheating to protect the battery. The connecting part 13 is used to connect with the rivet 7 and the external circuit. The setting of the protective component 8 further improves the reliability of the fuse.

[0034] The inner insulating pad 2 includes a gasket 21. The upper end face of the gasket 21 has a clearance hole 22, which is embedded in the liquid injection hole 33 of the aluminum cover 3 to facilitate the injection of electrolyte into the battery. The upper end of the riveting hole 9 of the gasket 21 is extended to form a receiving hole 25. The sealing ring 6 is embedded in the connection between the receiving hole 25 and the aluminum cover 3. The sealing ring 6 is embedded in the protrusion of the rivet 7 to insulate the rivet 7 from the aluminum cover 3 and prevent conductivity. The bottom surface of the gasket 21 is fixedly installed with a step 24, and the upper end face of the gasket 21 is provided with a circular boss 23. The step 24 structure of the inner insulating pad 2 helps its positioning and installation in the battery housing. The clearance hole 22 provides installation space for the liquid injection hole 33 of the aluminum cover 3. The circular boss 23 cooperates with the circular positioning hole 32 on the aluminum cover 3 to ensure accurate alignment during assembly and prevent misalignment. The receiving hole 25 is used to accommodate and position the sealing ring 6.

[0035] The aluminum cover 3 includes a cover plate 31. A QR code 34 is fixedly installed on one side of the upper end face of the cover plate 31 to facilitate battery traceability. A liquid injection hole 33 is protruding from the bottom surface of the cover plate 31 and is embedded in the clearance hole 22. A circular positioning hole 32 is opened on the bottom surface of the cover plate 31. The concave circular hole of the circular positioning hole 32 is the same size as the circular boss 23. During the assembly of the cover plate, the inner insulating pad 2 and the aluminum cover 3 are embedded and installed through the circular positioning hole 32 and the circular boss 23. The inner insulating pad 2 and the aluminum cover 3 are precisely positioned. The QR code 34 is used to store battery identification information to facilitate production management and traceability. The liquid injection hole 33 is used for electrolyte filling before battery formation and needs to be sealed afterwards. The circular positioning hole 32 and the circular boss 23 of the inner insulating pad 2 are precisely matched and are key structural features for achieving fast and accurate assembly.

[0036] The upper end face of the outer insulating pad 4 is provided with a recessed groove, the depth of which is the same as the height of the pole post 5. After the outer insulating pad 4 and the pole post 5 are assembled, their upper surfaces are flush, making it easier to assemble the pole post 5 and the outer insulating pad 4. The outer insulating pad 4 insulates the pole post 5 from the aluminum cover 3 to prevent conductivity. The recessed design on the upper end face of the outer insulating pad 4 ensures that the upper surface of the pole post 5 is flush with the upper surface of the outer insulating pad 4 after it is inserted. This not only simplifies the subsequent welding process and makes the welding surface flat, but also ensures the flatness and mechanical strength of the overall structure of the cover plate.

[0037] The electrode post 5 includes an aluminum core 51, with an aluminum layer 52 on the upper end and a composite layer 53 on the lower end. The aluminum layer 52, aluminum core 51, and composite layer 53 are integrally formed by pressing. A connecting rod 54 is rotatably sleeved in the middle of the aluminum core 51, and the bottom of the connecting rod 54 is fixedly connected to the outer insulating pad 4. The aluminum core 51 ensures good welding compatibility and conductivity with the internal busbar. The upper aluminum layer 52 provides an interface for laser welding, while the lower composite layer 53 provides an interface for resistance welding. The connecting rod 5... 4 is a two-section hinged support assembly. A shaft is set in the middle of the aluminum core 51. The shaft is rotatably sleeved with the upper end of the connecting rod 54. The lower end of the connecting rod 54 is rotatably sleeved on the outer insulating pad 4, so that the aluminum core 51 can be flipped around the shaft as the rotation axis under the support of the connecting rod 54, so that the upper and lower surfaces of the aluminum core 51 can be interchanged. By rotating the pole post 5 through the connecting rod 54, the aluminum layer 52 or the composite layer 53 can be selected to face upward, so as to flexibly adapt to laser welding or resistance welding processes. Pressing and molding into one piece ensures excellent electrical connection performance and mechanical strength between each layer.

[0038] The aluminum core 51 is an aluminum plate, the aluminum layer 52 is an aluminum strip, and the composite layer 53 is either nickel or an aluminum-nickel composite strip. When the composite layer 53 is nickel, its thickness is 1mm to 5mm; when the composite layer 53 is an aluminum-nickel composite strip, the nickel layer faces outward as the resistance welding surface, and its thickness is 1mm to 5mm, of which the nickel layer thickness is 0.1mm to 4.9mm. The choice of nickel or aluminum-nickel composite strip provides good resistance welding performance. At the same time, since aluminum is cheaper than nickel, it can save costs. The thickness specification of 1mm-5mm ensures sufficient material strength and heat capacity during welding to ensure the firmness and reliability of the weld point. For the aluminum-nickel composite strip, the nickel layer is clearly defined as the welding surface, and the minimum thickness of the nickel layer is specified. This is to ensure that the welding interface has sufficient nickel material, thereby achieving stable and reliable resistance welding with the steel connecting piece.

[0039] The protective component 8 includes a support frame 81, which is welded and fixedly installed on the bottom surface of the inner insulating pad 2. Two pressure plates 82 are symmetrically and movably installed at both ends of the support frame 81. One end of the pressure plate 82 is connected upward to a tension spring 83, the upper end of which is welded and fixed to the inner insulating pad 2. The other end of the pressure plate 82 is connected downward to a temperature control spring 84, the bottom end of which is welded and fixed to the manifold 11. Under normal conditions, the two pressure plates 82 are kept at a constant water level by the balanced force of the tension spring 83 and the temperature control spring 84. The pressure plate 82 is pressed flat above the bending area of ​​the fuse part 12 to prevent it from loosening or excessively deforming. The temperature control spring 84 is made of a shape memory alloy or similar material that loses its elasticity at a specific temperature, such as near the melting temperature. When abnormal heating causes the temperature to rise to the critical point, the temperature control spring 84 fails, the balance is broken, and the tension of the tension spring 83 will quickly pull the pressure plate 82 downward, actively breaking the fuse part 12 that may not be completely separated due to the adhesion of molten metal, ensuring that the circuit is completely broken and effectively preventing fuse failure.

[0040] The receiving hole 25 controls the compression ratio of the sealing ring 6 during riveting to be between 15% and 35%. The sealing ring 6 is compressed to a certain ratio during riveting to achieve a sealing effect on the riveting hole 9 on the aluminum cover 3, avoiding the risk of battery leakage due to poor airtightness of the cover. If the compression ratio of the sealing ring 6 is too low, it may lead to poor sealing and leakage risk; if the compression ratio is too high, it may over-compress the sealing ring, causing permanent deformation or even tearing. The structure of the receiving hole 25 precisely controls the compression of the sealing ring 6 to be within the optimal range.

[0041] Specifically, when using this resistance-welded aluminum cylindrical battery cover: First, rivet 7 is passed through the riveting hole 9 of the busbar 1, and the two are firmly connected using ultrasonic welding to form a sub-component. The sealing ring 6 is placed into the receiving hole 25 of the inner insulating pad 2. The pre-installed busbar 1 and rivet 7 sub-component, the inner insulating pad 2 with the sealing ring 6 installed, the aluminum cover 3, the outer insulating pad 4, and the terminal post 5 are stacked sequentially. Precise positioning is achieved using the circular boss 23 of the inner insulating pad 2 and the circular positioning hole 32 of the aluminum cover 3. The ends of rivets 7 are riveted using a riveting device to press and fix all components together, forming a complete battery cover. During this process, the sealing ring 6 is compressed to a predetermined ratio of 15%-35% to ensure the sealing at the riveting hole. Adjustments can be made according to customer requirements or production needs. The process involves rotating the terminal post 5. If resistance welding is used, the nickel side of the composite layer 53 faces upward; if laser welding is used, the aluminum layer 52 faces upward. The assembled cover plate is placed into the opening of the battery aluminum shell, and the edge of the aluminum cover 3 is sealed and welded to the battery aluminum shell by laser welding. The external connecting piece, usually made of steel, is connected to the upper surface of the terminal post 5 by resistance welding or laser welding using a selected welding process. When the battery is working normally, the pressure plate 82 of the protective component 8 stably presses down on the fuse part 12. If abnormal overcurrent or overheating occurs, the fuse part 12 melts, and at the same time, the temperature control spring 84 fails due to heat. The tension spring 83 pulls the pressure plate 82 to completely break the fuse point, ensuring that the circuit is disconnected and playing a safety protection role. The contents not described in detail in this description belong to the prior art known to those skilled in the art.

[0042] The above embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Although the invention has been described in detail with reference to the embodiments, those skilled in the art should understand that various combinations, modifications, or equivalent substitutions of the technical solutions of the invention do not depart from the spirit and scope of the invention and should be covered within the scope of the claims of the invention.

Claims

1. A resistance-welded aluminum-cased cylindrical battery cover, comprising a busbar (1), an inner insulating pad (2), an aluminum cover (3), an outer insulating pad (4), a terminal post (5), and a rivet (7) assembly, characterized in that: The busbar (1), inner insulating pad (2), aluminum cover (3), outer insulating pad (4), and pole (5) assembly all have riveting holes (9). The rivet (7) passes through the riveting hole (9) of the busbar (1) and is ultrasonically welded together to form a cover plate component. The cover plate component formed by ultrasonically welding the busbar (1) and the rivet (7) is riveted together with the inner insulating pad (2), aluminum cover (3), outer insulating pad (4), and pole (5) to form a cover plate. The riveting holes (9) on the inner insulating pad (2) and aluminum cover (3) are provided with sealing rings (6). The busbar (1) includes a busbar part (11), a fuse part (12), and a connecting part (13). A protective component (8) is connected in the middle of the fuse part (12). The pole (5) includes an aluminum core (51). An aluminum layer is provided on the upper surface of the aluminum core (51). 52), the lower end of the aluminum core (51) is provided with a composite layer (53). The aluminum layer (52), aluminum core (51) and composite layer (53) are pressed together as one piece. The middle of the aluminum core (51) is rotatably sleeved with a connecting rod (54). The bottom of the connecting rod (54) is fixedly connected to the outer insulating pad (4). The protective component (8) includes a support frame (81). The support frame (81) is welded and fixedly installed on the bottom surface of the inner insulating pad (2). Two pressure plates (82) are symmetrically and movably installed at both ends of the support frame (81). One end of the pressure plate (82) is connected upward with a tension spring (83). The upper end of the tension spring (83) is welded and fixed to the inner insulating pad (2). The other end of the pressure plate (82) is connected downward with a temperature control spring (84). The bottom end of the temperature control spring (84) is welded and fixed to the busbar (11).

2. The resistance-welded aluminum-cased cylindrical battery cover plate according to claim 1, characterized in that: The inner insulating pad (2) includes a gasket (21), the upper end face of the gasket (21) is provided with a clearance hole (22), and the upper end of the rivet hole (9) of the gasket (21) is extended to provide a receiving hole (25). The sealing ring (6) is embedded in the connection between the receiving hole (25) and the aluminum cover (3) to insulate the rivet (7) and the aluminum cover (3). The bottom surface of the gasket (21) is fixedly installed with a step (24), and the upper end face of the gasket (21) is provided with a circular boss (23).

3. The resistance-welded aluminum-cased cylindrical battery cover plate according to claim 2, characterized in that: The aluminum cover (3) includes a cover plate (31). A QR code (34) is fixedly installed on one side of the upper end face of the cover plate (31). An injection hole (33) is protruding from the bottom surface of the cover plate (31). The injection hole (33) is embedded in the clearance hole (22). A circular positioning hole (32) is opened on the bottom surface of the cover plate (31). The concave circular hole of the circular positioning hole (32) is the same size as the circular boss (23). When the cover plate is assembled, the inner insulating pad (2) and the aluminum cover (3) are embedded and installed through the circular positioning hole (32) and the circular boss (23). The inner insulating pad (2) and the aluminum cover (3) are precisely positioned.

4. The resistance-welded aluminum-cased cylindrical battery cover plate according to claim 1, characterized in that: The upper end face of the outer insulating pad (4) is provided with a recessed groove, the depth of which is consistent with the height of the pole post (5). After the outer insulating pad (4) and the pole post (5) are assembled, their upper surfaces are flush.

5. The resistance-welded aluminum-cased cylindrical battery cover plate according to claim 1, characterized in that: The aluminum core (51) is an aluminum plate, the aluminum layer (52) is an aluminum strip, and the composite layer (53) is either nickel or aluminum-nickel composite strip. When the composite layer (53) is nickel, its thickness is 1 mm to 5 mm. When the composite layer (53) is aluminum-nickel composite strip, the nickel layer faces outward as the resistance welding surface, and its thickness is 1 mm to 5 mm, wherein the thickness of the nickel layer is 0.1 mm to 4.9 mm.

6. The resistance-welded aluminum-cased cylindrical battery cover plate according to claim 2, characterized in that: The receiving hole (25) controls the compression ratio of the sealing ring (6) during riveting to be between 15% and 35%.

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