Secondary battery cover plate and production process thereof

Abstract

The invention relates to the technical field of secondary battery cover plates, in particular to a secondary battery cover plate and a production process thereof, and the secondary battery cover plate comprises a light aluminum plate which is provided with a through hole along the thickness direction; the pole body is positioned in the through hole, and the outer wall is in insulated connection with the light aluminum plate; according to the secondary battery cover plate and the production process thereof, the pole body, the upper plastic, the sealing ring, the light aluminum plate, the lower plastic cover plate and the metal fixing piece are sequentially stacked and are assembled in a single welding manner, so that the operation is simple and time-saving, the product is firm and reliable, the production cost is reduced, and the subsequent automatic assembly work is facilitated; the pole body and the metal fixing piece are made of the same material, so that the integration is better during welding, and the process difficulty of welding is reduced; the metal fixing piece is arranged at the lower mounting part and the lower plastic cover plate in an embedded manner, so that the welding effect is improved, the metal fixing piece and the lower surface of the pole body are subjected to fusion welding, and welding slag cannot fall into the electrode to cause short circuit in the use process of the electrode.

Description

A secondary battery cover and its manufacturing process Technical Field

[0001] This invention relates to the field of secondary battery cover technology, specifically to a secondary battery cover and its manufacturing process. Background Technology

[0002] The secondary battery cover, also known as the top cover assembly, is a core integrated structural component on the top of secondary batteries such as lithium-ion batteries and nickel-metal hydride batteries. It is usually fixed to the battery's metal casing by means of laser welding or other methods, creating a closed protective space for the bare cells inside the battery. At the same time, it integrates functional components such as current conduction, safety pressure relief, insulation isolation, and electrolyte filling adaptation. It is a key hub connecting the battery's internal cells with the external circuit and realizing battery safety protection and energy interaction.

[0003] It can form a sealed cavity with the shell to prevent electrolyte leakage, external moisture or impurities from entering, protect the structural integrity of the internal cells, and maintain the environmental stability for normal electrochemical reactions of the battery. It is precisely connected to the cell tabs through positive and negative terminals and adapter plates, becoming the energy transmission channel for battery charging and discharging, realizing the current interaction between the battery and the external circuit. It also integrates safety components such as explosion-proof plates, flip plates or fuses, which can automatically complete pressure relief or circuit cut-off under abnormal conditions such as battery overcharging, short circuit, thermal runaway, etc., to avoid safety accidents such as explosion and fire from the source.

[0004] It has the advantages of ensuring stable electrochemical performance of batteries, extending service life, building a multi-level safety protection system, avoiding usage risks, achieving efficient and reliable energy transmission, adapting to modular packaging and achieving internal insulation isolation, and preventing internal short circuits from the source.

[0005] Chinese Patent No. CN120376841A discloses a top cover assembly and its processing method. The top cover assembly includes: a top cover plate having a first pole through hole; a pole, insulatedly disposed on the top cover plate and located at the first pole through hole; a fixing frame disposed on the top cover plate, the fixing frame having a second pole through hole, the fixing frame extending to form an extension wall, the extension wall at least partially covering the outer edge of the pole and leaving a gap between it and the pole; a pole cap disposed around the outside of the pole and connected to the top cover plate, the pole, and the fixing frame respectively; and a lower plastic cover plate having a third pole through hole, the top cover plate being disposed on the lower plastic cover plate and connected to the lower plastic cover plate. The processing method is used to process the above-mentioned top cover assembly.

[0006] The above processing method involves first assembling the positive and negative terminals with the plastic bracket under the aluminum plate, then installing metal fasteners and welding them to the aluminum plate, and finally placing the welded top cover assembly into the mold for injection molding to obtain the plastic.

[0007] However, the aforementioned welding is a through-weld performed on the bottom of the aluminum plate, which is technically difficult, has poor stability, and is prone to loosening after welding. Furthermore, the high temperature and pressure during the injection molding process of placing the assembled components into the mold to obtain the upper plastic can cause changes in the material properties of the assembled components, altering the product properties and leading to damage and scrapping of the component materials, thus increasing production costs and reducing manufacturing efficiency. Secondly, the process of fixing the aluminum plate to the lower plastic using hot-melt is cumbersome, time-consuming, and labor-intensive. Summary of the Invention

[0008] To address the aforementioned issues, a secondary battery cover and its manufacturing process are provided. The assembly involves sequentially stacking and single-welding the electrode body, upper plastic and sealing ring, aluminum plate, lower plastic cover, and metal fasteners. This streamlined and time-saving process ensures a robust and reliable product while reducing production costs and facilitating subsequent automated assembly. The electrode body and metal fasteners are made of the same material, resulting in better fusion during welding and significantly reducing welding complexity. The metal fasteners are embedded in the lower mounting section and the lower plastic cover, improving welding efficiency. Furthermore, the metal fasteners are fused to the lower surface of the electrode body, preventing weld slag from falling into the electrode and causing short circuits during use.

[0009] To address the problems of existing technologies, this invention provides a secondary battery cover and its manufacturing process, comprising: a plain aluminum plate with a perforation along its thickness direction; an electrode body located within the perforation and whose outer wall is insulated from the plain aluminum plate; the electrode body having a lower mounting portion coaxially arranged with an outer diameter smaller than the perforation diameter, and an upper mounting portion with an outer diameter larger than the perforation diameter; an upper plastic material coaxially sleeved on the outer side of the upper mounting portion and in contact with its outer wall; and a material coaxially sleeved at the junction of the upper mounting portion and the lower mounting portion and in contact with the outer wall at that junction. The sealing ring is horizontally located at the inner ring of the upper plastic part; the inner ring of the upper plastic part extends toward the sealing ring and is provided with a limiting part whose upper surface contacts the bottom surface of the upper mounting part, and the lower surface of the limiting part contacts the upper surface of the aluminum plate; a lower plastic cover plate and a metal fastener are arranged sequentially from top to bottom on the outer side of the lower mounting part, and the metal fastener is arranged in a ring shape; the metal fastener is coaxially assembled on the outer periphery of the lower mounting part and cooperates with the upper mounting part to limit the upper plastic part, the sealing ring and the lower plastic cover plate on the aluminum plate.

[0010] Preferably, the upper surface of the lower plastic cover plate is in close contact with the lower surface of the aluminum plate and has an installation groove for the lower mounting part to pass through, and the inner wall of the installation groove is in contact with the outer wall of the lower mounting part; the bottom of the upper plastic cover plate has multiple positioning posts extending vertically downward, and the aluminum plate has positioning holes that cooperate with the positioning posts.

[0011] Preferably, the vertical cross-section of the metal fastener is rectangular, the lower mounting portion has an annular groove that mates with the metal fastener, and the lower plastic cover has an annular pressure groove that mates with the metal fastener; or, the vertical cross-section of the metal fastener is Z-shaped, the upper half of the Z-shape is an extension, and the lower half of the Z-shape is a limiting portion that abuts against and limits the lower plastic cover; the extension extends vertically to the inner ring of the sealing ring, the extension is coaxially welded to the outer side of the lower mounting portion, the lower mounting portion has an annular groove that mates with the extension, and the lower plastic cover has an annular pressure groove that mates with the limiting portion.

[0012] Preferably, the vertical cross-section of the sealing ring is an inverted "L" shape, and the sealing ring has an upper ring body and a lower ring body.

[0013] Preferably, the upper ring extends toward the inner wall of the upper plastic, and the lower ring extends vertically to the bottom to abut against the upper surface of the lower plastic cover, with the outer wall of the lower ring contacting the inner wall of the perforation.

[0014] Preferably, both the electrode body and the metal fastener are made of aluminum; or, both the electrode body and the metal fastener are made of copper.

[0015] Preferably, both the perforated position on the aluminum plate and the mounting groove position on the lower plastic cover plate are provided with a boss coaxial with the pole body, and the bottom of the boss is recessed inward.

[0016] Preferably, the upper surface of the boss at the lower plastic cover plate contacts the bottom surface of the boss at the aluminum plate, and the lower surface of the boss at the lower plastic cover plate contacts the upper surface of the metal fastener.

[0017] A manufacturing process for a secondary battery cover includes the following installation steps: S1: Take the terminal body and place the sealing ring and upper plastic sleeve on its outside; S2: Take the aluminum plate and install it onto the terminal body through a perforation; S3: Remove the plastic cover and place the lower plastic cover on the outside of the terminal body through an installation groove until it contacts the bottom of the aluminum plate; S4: Take the metal fastener and place it at the annular groove and annular pressing groove; S5: Use a welding gun to weld the metal fastener to the annular groove by hot melting. At this time, the metal fastener and the upper mounting part of the terminal body cooperate to limit the contact between the upper plastic sleeve, the sealing ring, the lower plastic cover, and the aluminum plate.

[0018] Preferably, the aluminum plate is also equipped with an explosion-proof valve and a sealing nail, and the top of the sealing nail has several open-top grooves along the radial direction; the entire assembly process of the secondary battery cover is carried out with the electrode body as the base; the installation order of the sealing ring and the upper plastic is not important.

[0019] The advantages of this invention compared to the prior art are: 1. It is assembled by stacking the electrode body, upper plastic and sealing ring, aluminum plate, lower plastic cover and metal fastener in sequence. Finally, the assembly of the secondary battery cover can be completed by a single welding of the metal fastener to the electrode body. The operation is simple, time-saving and labor-saving, without extra steps and procedures. The assembled product is firm and reliable, and the production cost is greatly reduced, which facilitates the automated assembly work.

[0020] 2. The pole body and the metal fastener are made of the same material, which improves the fusion of the two during welding and greatly reduces the difficulty of the welding process.

[0021] 3. The metal fastener is embedded in the lower mounting part and the lower plastic cover plate, which improves the welding effect between the metal fastener and the electrode body. During the welding process, only the lower surface of the metal fastener and the electrode body will be fused together. No welding slag will fall into the electrode and cause a short circuit during use. Attached Figure Description

[0022] Figure 1 is a top-view three-dimensional structural diagram of a secondary battery cover.

[0023] Figure 2 is a schematic diagram of the three-dimensional structure of a secondary battery cover plate from below and its annular groove.

[0024] Figure 3 is a three-dimensional cross-sectional structural diagram of an embodiment of a secondary battery cover.

[0025] Figure 4 is an exploded view of a secondary battery cover.

[0026] Figure 5 is a three-dimensional structural diagram of the electrode body, metal fastener, and annular groove of a secondary battery cover according to Embodiment 1.

[0027] Figure 6 is a three-dimensional cross-sectional structural diagram of a secondary battery cover plate according to Embodiment 2.

[0028] Figure 7 is a three-dimensional structural diagram of the electrode body, metal fastener, and annular groove of a secondary battery cover, according to Embodiment 2.

[0029] Figure 8 is a three-dimensional structural diagram of a metal fastener for a secondary battery cover, according to Embodiment 2.

[0030] Figure 9 is a partial schematic diagram of the annular groove in one embodiment of a secondary battery cover.

[0031] Figure 10 is a partial schematic diagram of the annular groove in a second embodiment of a secondary battery cover.

[0032] The following are the labels in the diagram: 1. Aluminum plate; 2. Pole post body; 3. Upper plastic; 3a. Positioning post; 4. Sealing ring; 5. Lower plastic cover plate; 6. Metal fastener; 7. Explosion-proof valve; 8. Sealing nail. Detailed Implementation

[0033] To further understand the features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0034] Referring to Figures 1 to 4, a secondary battery cover plate and its manufacturing process include: a plain aluminum plate 1 with a perforation along its thickness direction; an electrode body 2 located inside the perforation and its outer wall insulated from the plain aluminum plate 1, wherein the electrode body 2 has a lower mounting part coaxially arranged and with an outer diameter smaller than the diameter of the perforation, and an upper mounting part with an outer diameter larger than the diameter of the perforation.

[0035] It should be noted that during installation, the lower mounting part will easily pass through the perforation, while the upper mounting part will abut against the upper surface of the aluminum plate 1.

[0036] Referring to Figures 1, 3, and 4, an upper plastic 3 is coaxially sleeved on the outer side of the upper mounting part, which contacts its outer wall. A sealing ring 4 is coaxially sleeved at the junction of the upper mounting part and the lower mounting part, which contacts the outer wall at that location. The sealing ring 4 is horizontally located at the inner ring of the upper plastic 3.

[0037] It should be noted that the upper mounting part will abut against the upper surface of the aluminum plate 1, which can better compress and limit the sealing ring 4 and the upper plastic 3 located at the upper mounting part and the upper surface of the aluminum plate 1.

[0038] Referring to Figure 3, the inner ring of the upper plastic 3 extends toward the sealing ring 4 and is provided with a limiting part whose upper surface contacts the bottom surface of the upper mounting part, and the lower surface of the limiting part contacts the upper surface of the aluminum plate 1.

[0039] It should be noted that the limiting part is the part that contacts the lower surface of the upper mounting part for main limiting; at the same time, the extension of the limiting part and the sealing ring 4 are reserved with a gap, which not only provides elastic space for the sealing ring 4, but also avoids excessive deformation of the sealing ring 4 during the compression process, thereby achieving the purpose of extending the service life of the sealing ring.

[0040] Referring to Figures 2 to 4, a lower plastic cover plate 5 and a metal fastener 6 are arranged sequentially from top to bottom on the outer side of the lower mounting part. The metal fastener 6 is arranged in a ring shape. The metal fastener 6 is coaxially assembled on the outer periphery of the lower mounting part and cooperates with the upper mounting part to limit the upper plastic 3, the sealing ring 4 and the lower plastic cover plate 5 on the aluminum plate 1.

[0041] It should be noted that the pole body 2 and the metal fastener 6 are made of the same material, which makes the two more compatible during welding and greatly reduces the difficulty of the welding process.

[0042] The lower mounting part and the bottom of the lower plastic cover plate 5 have a pre-drilled annular groove for the metal fastener 6. During assembly, the metal fastener needs to be placed in the annular groove before welding. Therefore, after welding, the metal fastener 6 will be embedded in the lower mounting part and the lower plastic cover plate 5, which improves the welding effect between the metal fastener 6 and the electrode body 2. During the welding process, only the lower surface of the metal fastener 6 and the electrode body 2 will be melted and welded. No welding slag will fall into the electrode during the welding process, causing a short circuit during use.

[0043] Referring to Figures 3 and 4, the upper surface of the lower plastic cover 5 is in close contact with the lower surface of the aluminum plate 1 and has an installation groove for the lower mounting part to pass through. The inner wall of the installation groove is in contact with the outer wall of the lower mounting part. The bottom of the upper plastic 3 has multiple positioning posts 3a extending vertically downward, and the aluminum plate 1 has positioning holes that cooperate with the positioning posts 3a.

[0044] It should be noted that the inner wall of the mounting groove contacts the outer wall of the lower mounting part to improve the positioning effect when the lower plastic cover plate 5 is stacked and assembled, thereby improving the installation accuracy during the entire stacking and assembly process; the positioning post 3a cooperates with the positioning hole to improve the assembly accuracy between the upper plastic 3 and the light aluminum plate 1, and can prevent relative rotation between the two during use.

[0045] Referring to Figures 3, 5, and 9, in Embodiment 1: the vertical cross-section of the metal fastener 6 is rectangular, the lower mounting portion has an annular groove that mates with the metal fastener 6, and the lower plastic cover plate 5 has an annular pressure groove that mates with the metal fastener 6. It should be noted that the annular groove and annular pressure groove are key to the embedded installation of the metal fastener 6 at the lower mounting portion and the lower plastic cover plate 5. The annular groove and annular pressure groove are reserved spaces for the metal fastener 6. Furthermore, the lower mounting portion is stepped after the annular groove is opened, avoiding the gap after the lower mounting portion and the lower plastic cover plate 5 are assembled, which can prevent welding slag from falling into the gap and causing short circuit problems.

[0046] Referring to Figures 6 to 8 and Figure 10, in Embodiment 2: the vertical cross-section of the metal fastener 6 is "Z" shaped. The upper half of the "Z" shape is an extension to reduce the amount of material used in the pole body 2, and the lower half of the "Z" shape is a limiting part that abuts against and limits the lower plastic cover plate 5. The extension extends vertically to the inner ring of the sealing ring 4. The extension is coaxially welded to the outer side of the lower mounting part. The lower mounting part has an annular groove that mates with the extension. The lower plastic cover plate 5 has an annular pressure groove that mates with the limiting part.

[0047] It should be noted that this configuration increases the amount of metal fastener 6 used and reduces the amount of electrode body 2 used. The manufacturing process of metal fastener 6 is less expensive than that of electrode body 2, thus effectively reducing the cost of using electrode body 2 and achieving the effect of cost reduction.

[0048] Referring to Figures 3 and 4, the vertical cross-section of the sealing ring 4 is an inverted "L" shape, and the sealing ring 4 has an upper ring body and a lower ring body.

[0049] The upper ring extends toward the inner wall of the upper plastic 3, and the lower ring extends vertically to the bottom to abut against the upper surface of the lower plastic cover plate 5, with the outer wall of the lower ring contacting the inner wall of the perforation.

[0050] It should be noted that the sealing ring 4 is used to center and compress the electrode body 2 while also deforming to adapt to the expansion or contraction of the electrode body 2 during use.

[0051] The lower ring is mainly used to center and limit the pole body 2, and the upper ring is used in conjunction with the upper plastic 3 to control the deformation. See Figures 3 and 6. In embodiment 3, both the pole body 2 and the metal fastener 6 are made of aluminum.

[0052] It should be noted that using aluminum as the sole material eliminates galvanic corrosion, and the consistent coefficient of thermal expansion prevents thermal stress cracking and sealing failure. Furthermore, aluminum-to-aluminum contact has low resistance and stable conductivity. At the same time, the uniform mechanical, process, and surface treatment properties make assembly and processing more convenient, and also enable lightweighting, reducing overall costs and adapting to the usage requirements of energy storage device terminals.

[0053] Example 4: Both the pole body 2 and the metal fastener 6 are made of copper.

[0054] It should be noted that using copper materials eliminates galvanic corrosion, and the consistent coefficient of thermal expansion prevents thermal stress cracking and sealing failure. Furthermore, copper has excellent electrical conductivity, resulting in lower contact resistance and more stable conductivity for materials of the same type. Moreover, the uniform process and surface treatment characteristics facilitate assembly and processing, improve mechanical compatibility, and significantly enhance the overall structural reliability.

[0055] Referring to Figures 3, 4 and 6, both the perforated position of the aluminum plate 1 and the mounting groove position of the lower plastic cover plate 5 are provided with a boss coaxial with the pole body 2, and the bottom of the boss is recessed inward.

[0056] The upper surface of the protrusions at the lower plastic cover plate 5 contacts the bottom surface of the protrusion at the aluminum plate 1, and the lower surface of the protrusions at the lower plastic cover plate 5 contacts the upper surface of the metal fastener 6.

[0057] It should be noted that the protrusions and recesses serve as guides and limits during assembly, further preventing misalignment of components during stacking and ensuring smooth placement of each component. This provides a foundation for automated processing of secondary battery covers.

[0058] A manufacturing process for a secondary battery cover includes the following installation steps: S1: Take the electrode body 2 and fit the sealing ring 4 and the upper plastic 3 on its outside; It should be noted that in this step, the sealing ring 4 and the upper plastic 3 are set side by side and there is no direct structural relationship between the two, so the stacking and assembly order does not matter.

[0059] S2: Take the light aluminum plate 1 and install it onto the pole body 2 through the perforation; it should be noted that in this step, the sealing ring 4 will fill the gap between the pole body 2 and the perforation to ensure that the pole body 2 can be centered and will not shake during use.

[0060] S3: Remove the plastic cover plate 5 and place the lower plastic cover plate 5 on the outside of the pole body 2 through the mounting groove until it contacts the bottom of the aluminum plate 1; it should be noted that at this time, the protrusion of the lower plastic cover plate 5 contacts the recess of the aluminum plate 1, which facilitates the stacking and assembly of the two.

[0061] S4: Take the metal fastener 6 and place it at the annular groove and the annular pressure groove; S5: Use a welding gun to weld the metal fastener 6 to the annular groove by hot melting. At this time, the metal fastener 6 and the upper mounting part of the pole body 2 cooperate to achieve the contact and limit of the upper plastic 3, sealing ring 4, lower plastic cover plate 5 and light aluminum plate 1.

[0062] The entire assembly process of the secondary battery cover is carried out using the electrode body 2 as a base.

[0063] It should be noted that the above operation requires the pole body 2 to be fixed first to facilitate the stacking and assembly process. After the pole body 2 is fixed, the subsequent stacking and assembly process is simple, and the structure of each part has been simplified accordingly. It can be completed by adsorption-type automated assembly to improve production efficiency.

[0064] Referring to Figures 1, 3, 4 and 6, the aluminum plate 1 is also equipped with an explosion-proof valve 7 and a sealing nail 8. The top of the sealing nail 8 has several open grooves along the radial direction.

[0065] It should be noted that the groove on the top of the sealing nail 8 can accommodate the changes in internal stress caused by heat when it is welded and assembled with the aluminum plate 1. This can increase the deformation and ductility of the sealing nail 8, thus solving the problem of poor sealing at the top caused by metal shrinkage in the dry heat-affected zone when the existing sealing nail 8 is welded and fixed to the aluminum plate 1. The explosion-proof valve 7 is used for explosion-proof pressure relief during subsequent use.

[0066] The above embodiments only illustrate one or more implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims

1. A secondary battery cover, characterized in that, include: A light aluminum plate (1) has a perforation along its thickness direction; an electrode body (2) is located inside the perforation and its outer wall is insulated from the light aluminum plate (1). The electrode body (2) has a lower mounting part coaxially arranged with an outer diameter smaller than the diameter of the perforation, and an upper mounting part with an outer diameter larger than the diameter of the perforation. An upper plastic (3) is coaxially sleeved on the outer side of the upper mounting part and contacts its outer wall. A sealing ring (4) is coaxially sleeved at the junction of the upper mounting part and the lower mounting part and contacts its outer wall. The sealing ring (4) is horizontally located on the inner ring of the upper plastic (3). The upper plastic (3) extends towards the sealing ring (4) and is provided with a limiting part whose upper surface contacts the bottom surface of the upper mounting part. The lower surface of the limiting part contacts the upper surface of the aluminum plate (1). The lower mounting part is provided with a lower plastic cover plate (5) and a metal fastener (6) from top to bottom on the outer side of the lower mounting part. The metal fastener (6) is arranged in a ring shape. The metal fastener (6) is coaxially assembled on the outer periphery of the lower mounting part and cooperates with the upper mounting part to limit the upper plastic (3), the sealing ring (4) and the lower plastic cover plate (5) on the aluminum plate (1).

2. The secondary battery cover plate according to claim 1, characterized in that, The upper surface of the lower plastic cover (5) is in close contact with the lower surface of the aluminum plate (1) and has an installation groove for the lower mounting part to pass through. The inner wall of the installation groove is in contact with the outer wall of the lower mounting part. The bottom of the upper plastic (3) has multiple positioning posts (3a) extending vertically downward. The aluminum plate (1) has positioning holes that cooperate with the positioning posts (3a).

3. A secondary battery cover according to claim 1, characterized in that, The vertical cross-section of the metal fastener (6) is rectangular, the lower mounting part has an annular groove that mates with the metal fastener (6), and the lower plastic cover plate (5) has an annular pressure groove that mates with the metal fastener (6); or, the vertical cross-section of the metal fastener (6) is "Z" shaped, the upper half of the "Z" shape is an extension, and the lower half of the "Z" shape is a limiting part that abuts against and limits the lower plastic cover plate (5); the extension extends vertically to the inner ring of the sealing ring (4), the extension is coaxially welded to the outer side of the lower mounting part, the lower mounting part has an annular groove that mates with the extension, and the lower plastic cover plate (5) has an annular pressure groove that mates with the limiting part.

4. A secondary battery cover according to claim 3, characterized in that, The vertical cross-section of the sealing ring (4) is an inverted "L" shape, and the sealing ring (4) has an upper ring body and a lower ring body.

5. A secondary battery cover according to claim 4, characterized in that, The upper ring extends toward the inner wall of the upper plastic (3), and the lower ring extends vertically to the bottom to abut against the upper surface of the lower plastic cover (5), and the outer wall of the lower ring contacts the inner wall of the perforation.

6. A secondary battery cover according to claim 3, characterized in that, The pole body (2) and the metal fastener (6) are both made of aluminum; or, the pole body (2) and the metal fastener (6) are both made of copper.

7. A secondary battery cover according to claim 6, characterized in that, The aluminum plate (1) with perforations and the lower plastic cover plate (5) with mounting grooves are both provided with bosses coaxial with the pole body (2), and the bottom of the bosses is recessed inward.

8. A secondary battery cover according to claim 7, characterized in that, The upper surface of the boss at the lower plastic cover plate (5) is in contact with the bottom surface of the boss at the aluminum plate (1), and the lower surface of the boss at the lower plastic cover plate (5) is in contact with the upper surface of the metal fastener (6).

9. A manufacturing process for a secondary battery cover, characterized in that, The secondary battery cover plate used in any one of claims 1-8 includes the following installation steps: S1: Take the electrode body (2) and put the sealing ring (4) and the upper plastic (3) on its outside; S2: Take the aluminum plate (1) and install the aluminum plate (1) on the electrode body (2) through the perforation; S3: Take off the plastic cover plate (5) and put the lower plastic cover plate (5) on the outside of the electrode body (2) through the installation groove until it contacts the bottom of the aluminum plate (1); S4: Take the metal fastener (6) and place the metal fastener (6) at the annular groove and the annular pressure groove; S5: Use a welding gun to weld the metal fastener (6) to the annular groove by hot melting. At this time, the metal fastener (6) cooperates with the upper mounting part of the electrode body (2) to realize the contact and limiting of the upper plastic (3), sealing ring (4), lower plastic cover plate (5) and aluminum plate (1).

10. The manufacturing process of a secondary battery cover according to claim 9, characterized in that, The aluminum plate (1) is also equipped with an explosion-proof valve (7) and a sealing nail (8) for explosion-proof pressure relief. The top of the sealing nail (8) has several open grooves along the radial direction. The entire assembly process of the secondary battery cover is based on the electrode body (2). The installation order of the sealing ring (4) and the upper plastic (3) is not important.

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