Secondary battery cover plate structure and production process thereof

Abstract

The invention relates to a secondary battery cover plate structure and a production process thereof, and the structure comprises a top cover plate which is provided with a first pole through hole, and the upper surface of the top cover plate protrudes upwards to form a welding boss; the pole is arranged on the top cover plate in an insulating manner; the lower support is provided with a second pole through hole, and the top cover plate is arranged on the lower support and connected with the lower support; the fixed cover is made of a metal material, is provided with a third pole through hole, covers the welding boss and is welded with the welding boss; and the pole cap is arranged on the outer side of the pole in a surrounding manner and is respectively connected with the top cover plate, the pole and the fixed cover. The production process is used for producing the cover plate structure. According to the structure, welding and fixing can be conducted from the top, welding operation is more convenient, the production efficiency of products can be improved, the reject ratio can be reduced, in addition, the influence of high temperature in the welding process on the sealing piece can be reduced or avoided, and the air tightness of the products is guaranteed.

Description

Technical Field

[0001] The present application relates to the technical field of secondary battery processing, and in particular to a secondary battery cover plate structure and a production process thereof. Background Art

[0002] In the existing power battery structure, the common square aluminum shell battery generally includes a shell, a battery cell and a top cover assembly. The battery cell is arranged in the shell, and the top cover assembly is used to close the shell. The top cover assembly usually includes a lower bracket, a top cover plate, a sealing ring and positive and negative bipolar poles. In addition, in order to strengthen the fixing effect on the pole and reduce the possibility of displacement and dislocation of the pole during use, a bracket will be set on the outside of the pole. The bracket is usually in a frame structure adapted to the pole, and is sleeved on the outside of the pole. The pole is fixed with the pole cap formed by injection molding. The bracket is usually made of metal material and is fixed to the top cover plate by welding during assembly.

[0003] For example, the Chinese patent application with application number CN202222348142.X and titled A top cover assembly and secondary battery of a secondary battery previously filed by the inventor discloses a top cover assembly and a secondary battery of a secondary battery, the top cover assembly comprising: a top cover plate having a first pole through hole penetrating in the thickness direction, and the upper surface of the top cover plate is formed with a through welding groove surrounding the first pole through hole on the outside of the first pole through hole; a pole; a bracket, which is adapted to the pole, and the pole is embedded in the bracket; a pole cap, which is arranged around the outside of the pole and is respectively connected to the pole and the bracket, and the lower end edge of the bracket extends to form a welding portion exposed outside the pole cap and adapted to the through welding groove, and the welding portion is arranged in the through welding groove and through-welded with the bottom surface of the through welding groove. In the above technical solution, the bracket is installed on the top cover plate by bottom through welding. The inventor found the following defects when actually applying the above structure for production:

[0004] First, since the components are loosely assembled before injection molding, the product cannot be turned over as a whole. When welding, the welding gun can only be moved upward from the bottom of the top cover plate to the penetration welding groove. There are many difficulties in welding from the bottom, such as inconvenience for welders to operate and difficulty in finding the welding position accurately, resulting in low overall production efficiency. In addition, the product defect rate is high due to inaccurate welding position and irregular welding operation.

[0005] Secondly, the bottom welding method, the welding position is close to the rubber seal, and the high temperature generated during the welding process may cause the seal to melt, which will affect the overall airtightness of the product and thus affect the product quality.

[0006] In summary, in the prior art, the bracket and the top cover plate are welded at the bottom, which has the defects of low production efficiency and affecting the air tightness of the product, and needs to be improved urgently. Summary of the invention

[0007] In order to solve the problems existing in the above-mentioned prior art, the purpose of this application is to provide a secondary battery cover plate structure and its production process. This application sets a welding boss on the top cover plate and improves the structure of the fixed cover, so that the fixed cover can be quickly positioned when assembled, and can be welded and fixed from the top, which is more convenient for welding operations, which is conducive to improving the production efficiency of the product and reducing the defective rate. In addition, it can also reduce or avoid the impact of high temperature on the seal during the welding process, and ensure the airtightness of the product.

[0008] A secondary battery cover structure described in the present application includes:

[0009] A top cover plate having a first pole through hole penetrating along a thickness direction, wherein an upper surface of the top cover plate protrudes upwards at the periphery of the first pole through hole to form a welding boss;

[0010] A pole, which is insulated and arranged on the top cover plate and located at the first pole through hole;

[0011] A lower bracket, which has a second pole through hole penetrating along the thickness direction, the position of the second pole through hole corresponds to the position of the first pole through hole, and the top cover plate is arranged on the lower bracket and connected to the lower bracket;

[0012] A fixed cover, which is made of metal material, has a third pole through hole penetrating along the thickness direction, and is arranged on the welding boss and welded to the welding boss;

[0013] The pole cap is arranged around the outer side of the pole and is respectively connected with the top cover plate, the pole and the fixing cover.

[0014] Preferably, the fixing cover includes a welding portion and an outer edge portion perpendicular to the welding portion, a welding groove adapted to the welding boss is formed between the welding portion and the outer edge portion, the welding portion is welded to the welding boss, and the outer edge portion abuts against the outer side wall of the welding boss.

[0015] Preferably, the inner edge of the fixing cover is recessed inward to form a glue injection groove.

[0016] Preferably, the width of the welding portion is greater than the width of the welding boss, so that the inner edge of the welding portion extends to be located above the pole.

[0017] Preferably, the lower bracket is formed with a snap-on portion on the outer side of the second pole through-hole, and the upper end of the snap-on portion extends outward to form a snap-on outer edge, and a slot is formed between the snap-on outer edge and the upper surface of the lower bracket, and the height of the slot is adapted to the inner edge thickness of the first pole through-hole, and the top cover plate and the lower bracket are snap-on with each other through the snap-on outer edge.

[0018] Preferably, the secondary battery cover structure further includes:

[0019] A sealing member is arranged between the top cover plate and the pole and sleeved on the outer side of the buckle portion.

[0020] Preferably, the secondary battery cover structure further includes:

[0021] A connecting piece is arranged on a surface of the lower bracket away from the top cover plate, and at least a part of the connecting piece is located outside the second pole through hole and abuts against the lower bracket, and the connecting piece is also connected to the pole.

[0022] Preferably, the connecting piece is in a sheet shape, one end of which is in contact with the lower bracket, and the other end has an exposure hole corresponding to the second pole through hole, the inner edge of the exposure hole extends upward to form an inner edge portion, and the inner edge portion is connected to the pole.

[0023] A production process of a secondary battery cover plate structure of the present application is used to process the secondary battery cover plate structure as described above, comprising the following steps:

[0024] S01. Prepare suitable top cover plates, poles, lower brackets and fixed covers for standby use;

[0025] S02. Take the explosion-proof valve and install it in the explosion-proof valve installation hole of the top cover plate;

[0026] S03, connecting the lower bracket to the top cover plate;

[0027] S04, take the sealing member and install it on the top cover plate;

[0028] S05, inserting a pole into the first pole through hole of the top cover plate;

[0029] S06. Take the fixed cover and install it on the top cover plate, so that the fixed cover covers the welding boss of the top cover plate, and weld from the position corresponding to the welding boss on the upper surface of the fixed cover to weld and fix the fixed cover to the top cover plate;

[0030] S07, placing the integrated structure formed by the top cover plate, the seal, the pole and the fixing frame into a mold and injection molding the outside of the pole to form a pole cap;

[0031] S08, marking the obtained top cover assembly, and attaching a protective film to the explosion-proof valve, and then performing a helium test and an insulation withstand voltage test. After passing the test, the secondary battery cover plate structure is obtained.

[0032] Preferably, step S07 further includes:

[0033] Take the connecting piece and install it on the side of the lower bracket away from the top cover plate, so that part of the connecting piece abuts against the lower bracket and part is connected to the pole.

[0034] The advantages of a secondary battery cover plate structure and its production process described in this application are:

[0035] 1. The present application forms a welding boss by extending upward from the periphery of the first pole through hole of the top cover plate, and forms a fixed cover of a cover-like structure by improving the structure of the bracket, and forms a welding groove matched with the welding boss on the lower surface of the fixed cover. The structure of the welding groove and the welding boss can achieve fast and accurate positioning when the fixed cover is assembled on the top cover plate. In addition, since the traditional bracket structure is changed to a cover-like structure, the thickness of the upper part of the fixed cover is thinner, and the fixed cover can be welded to the welding boss by penetration welding from the top of the fixed cover, that is, the fixed cover and the top cover plate can be welded at the top. Compared with the bottom welding method in the prior art, this welding structure is more convenient for welding personnel to operate and is also convenient for determining the welding position, which can improve the overall production efficiency of the product, and at the same time can also improve the product quality and reduce the defective rate;

[0036] 2. Due to the top welding method, the welding position is far away from the bottom sealing ring, which can effectively reduce or avoid the impact of high temperature on the seal during the welding process, reduce the probability of hot melting of the seal, effectively ensure the sealing effect of the seal, and thus ensure the airtightness of the product;

[0037] 3. The welding position of the present application is located at the position corresponding to the welding boss on the upper surface of the fixed cover. After welding and injection molding to form the pole cap, the welding position is wrapped by the pole cap. Compared with the structure in which the welding position is exposed after the bottom welding, the structure of the present application will not produce oxidation, which can ensure the continuous stability of the welding position. In addition, it also avoids the problem of exposed welds affecting the appearance;

[0038] 4. After the fixed cover of the present application is covered on the welding boss, the welding boss forms a step structure on the outside of the welding boss. The fixed cover and the top cover plate are welded to form a whole. The step structure will help to enhance the stability of the overall connection between the pole cap and the top cover plate, effectively reduce the upward dislocation phenomenon caused by the edge of the pole cap, and improve the quality of the product;

[0039] 5. The top cover plate and the lower bracket of the present application are fastened together by snap-fitting, which is easier to operate than the traditional hot-melt bonding method, helps to improve assembly efficiency, and reduce production energy consumption. It can also reduce or avoid the impact of the high temperature of hot melt on the seal, further ensuring the airtightness of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a structural schematic diagram of a secondary battery cover structure described in this embodiment;

[0041] Figure 2 yes Figure 1 Sectional view of the center pole position;

[0042] Figure 3 yes Figure 1 Exploded view of;

[0043] Figure 4 is a schematic diagram of the structure of the top cover plate of this embodiment;

[0044] Figure 5 yes Figure 4 Structural diagram of installing explosion-proof valve;

[0045] Figure 6 is a schematic structural diagram of the lower bracket described in this embodiment;

[0046] Figure 7 yes Figure 5 Schematic diagram of the structure after installing the lower bracket;

[0047] Figure 8 yes Figure 7 Schematic diagram of the structure after the seal is installed;

[0048] Fig. 9 yes Figure 8 Schematic diagram of the structure after the pole is installed;

[0049] Fig.10 is one of the structural schematic diagrams of the fixed cover described in this embodiment;

[0050] Fig.11 This is the second structural schematic diagram of the fixed cover described in this embodiment;

[0051] Fig.12 yes Fig. 9 Schematic diagram of the structure after the fixed cover is installed;

[0052] Fig.13 yes Fig.12 Schematic diagram of the structure after the polar cap is formed by injection molding;

[0053] Fig.14 is a schematic structural diagram of the connecting piece described in this embodiment;

[0054] Fig.15 yes Fig.13 Schematic diagram of the structure after the connecting piece is installed on the back of the lower bracket.

[0055] Explanation of the reference numerals: 1-top cover plate, 11-first pole through hole, 12-welding boss, 13-explosion-proof valve mounting hole, 14-liquid injection hole, 2-pole, 3-lower bracket, 31-second pole through hole, 32-buckle part, 4-fixing cover, 41-welding groove, 42-glue injection groove, 5-pole cap, 6-seal, 7-connecting piece, 71-exposure hole, 72-inner edge, 8-explosion-proof valve, 9-protective film, 10-sealing nail, A-welding point position. DETAILED DESCRIPTION

[0056] like Figure 1-Figure 15 As shown, a secondary battery cover structure described in the present application includes:

[0057] Top cover 1, as detailed in Figure 4 As shown, the top cover plate 1 is usually a square plate structure, which has a first pole through hole 11 that penetrates along the thickness direction, for the pole 2 to pass through, so that the pole 2 can be electrically connected to the battery cell inside the battery casing. In the bipolar column 2 structure, the number of the first pole through holes 11 is usually two, which are distributed at both ends of the length direction of the top cover plate 1 to correspond to the positive pole and the negative pole respectively. The top cover plate 1 is also provided with an explosion-proof valve mounting hole 13 and a liquid injection hole 14. The explosion-proof valve mounting hole 13 is used to install the explosion-proof valve 8, and the liquid injection hole 14 is used to inject electrolyte. The sealing nail 10 is used to inject the electrolyte and then insert it into the liquid injection hole 14 to achieve sealing.

[0058] The poles 2 are usually two in number, one is a positive pole and the other is a negative pole. The shape and size of the poles 2 are usually corresponding to the first pole vias 11 and are made of conductive materials. For the negative pole, Figure 2 As shown, the upper part is required to be made of aluminum material and the lower part is required to be made of copper material. In this embodiment, the pole 2 is a cylindrical structure. In other optional embodiments, the pole 2 can be a prism or other special-shaped structure. The present application does not limit the specific shape of the pole 2. The pole 2 is insulated and arranged on the top cover plate 1 and is located at the first pole through hole 11 of the top cover plate 1.

[0059] The lower bracket 3 is usually made of plastic material and has insulation properties. The lower bracket 3 is a long plate structure that matches the top cover plate 1, and is connected to the top cover plate 1. The lower bracket 3 is used to separate the top cover plate 1 from the battery housing, insulate the top cover plate 1 from the battery housing, and prevent the top cover plate 1 from contacting the battery cells inside the battery housing, thereby causing a short circuit. The lower bracket 3 has a second pole via 31 that penetrates along the thickness direction at a position corresponding to the first pole via 11.

[0060] In this embodiment, please continue to refer to Figure 4 In order to change the method of welding the bracket from the bottom of the top cover plate 1 in the prior art, the structure of the top cover plate 1 is improved. Specifically, the upper surface of the top cover plate 1 protrudes upward at the periphery of the first pole through hole 11 to form a welding boss 12. For example, corresponding to the circular first pole through hole 11, the welding boss 12 is annular.

[0061] Corresponding to the structure of the above-mentioned welding boss 12, the bracket is changed into a hollow cover-shaped structure, that is, the secondary battery cover plate structure of this embodiment also includes a fixed cover 4, which is supported by metal material and is in the shape of a hollow round cover. The middle part has a third pole through hole penetrating along the thickness direction for accommodating the pole 2. The lower surface of the fixed cover 4 has a welding groove 41 adapted to the welding boss 12. Specifically, corresponding to the annular welding boss 12, the welding groove 41 is a circular groove body, so that the fixed cover 4 can be covered on the top of the welding boss 12, so as to achieve fast and accurate positioning during welding, and ensure that the welding process is not easy to shift.

[0062] The fixing cover 4 and the welding boss 12 are fixed by top surface welding, that is, the welding gun is located on the upper surface of the fixing cover 4 and penetrates and welds from top to bottom.

[0063] The pole cap 5 is made by injection molding, formed on the outside of the pole 2, and connected to the top cover plate 1, the pole 2 and the fixed cover 4 respectively, so as to achieve insulation and sealing of the outer part of the pole 2 and connect the components into a whole.

[0064] Further, in this embodiment, the details are as follows Fig.10 , Fig.11 As shown, the fixed cover 4 includes a welding portion and an outer edge portion perpendicular to the welding portion, the above-mentioned welding groove 41 is formed between the welding portion and the outer edge portion, the welding portion is an annular plane, and the outer edge portion is an annular structure perpendicular to the welding portion. When the fixed cover 4 is welded, the fixed cover 4 is covered on the welding boss 12, the welding portion contacts the top surface of the welding boss 12, and the outer edge portion abuts against the outer side wall of the welding boss 12. This structure can facilitate the assembly and positioning of the fixed cover 4 during welding.

[0065] Furthermore, in the present embodiment, the inner edge of the fixed cover 4 is recessed inward to form a glue injection groove 42, into which glue will be injected during the subsequent injection molding process of the pole cap 5. After molding, the fixed cover 4 and the pole cap 5 can be relatively fixed in the circumferential direction to avoid circumferential dislocation of the fixed cover 4.

[0066] Further, in this embodiment, please refer to Figure 2The width of the welding portion is greater than the width of the welding boss 12. After the fixing cover 4 is installed above the welding boss 12, the inner edge of the welding portion will extend to the top of the pole 2. The advantage of this structure is that when the pole cap 5 is formed by injection molding, the colloid will flow into and fill between the welding portion and the pole 2. Through this structure, the freedom of movement of the pole 2 to shift upward can be effectively limited, thereby limiting the upward dislocation of the pole 2 and reducing the possibility of its upward dislocation.

[0067] Further, in this embodiment, please refer to Figure 6 , Figure 7 The lower bracket 3 is formed with a buckle portion 32 on the outer side of the second pole through hole 31, and the upper end of the buckle portion 32 extends outward to form a buckling outer edge, and a clamping groove is formed between the buckling outer edge and the upper surface of the lower bracket 3, and the height of the clamping groove is adapted to the inner edge thickness of the first pole through hole 11, that is, the height of the clamping groove is slightly larger than the inner edge thickness of the first pole through hole 11. When the top cover plate 1 and the lower bracket 3 are assembled, the buckle portion 32 is aligned with the first pole through hole 11, and the buckle portion 32 is passed through the first pole through hole 11. In this process, the buckle portion 32 is squeezed inward by the first pole through hole 11 and shrinks inward. After the buckling outer edge of the buckle portion 32 passes through the first pole through hole 11, the buckling outer edge opens outward and resets. At this time, the buckling outer edge is buckled at the first pole through hole 11 of the top cover plate 1, so that the top cover plate 1 and the lower bracket 3 are buckled.

[0068] Furthermore, in this embodiment, the secondary battery cover structure further includes:

[0069] The seal 6, specifically, is a rubber seal ring, which is arranged between the top cover plate 1 and the pole 2, and is sleeved on the outside of the buckle portion 32. The seal 6 is used to achieve the seal between the pole 2 and the top cover plate 1. In addition, combined with the structure of the buckle portion 32, the buckle portion 32 can play a role in positioning and installing the seal 6, so as to achieve rapid and accurate installation of the seal 6. In this embodiment, the outer side of the seal 6 extends outward to form four outer ears, and the four outer ears can make the filling between the pole 2 and the top cover plate 1 tighter.

[0070] Further, in this embodiment, please refer to Fig.14 , Fig.15 , the secondary battery cover structure further includes:

[0071] The connecting piece 7 is arranged on a side of the lower bracket 3 away from the top cover plate 1, that is, on the lower surface. At least part of the connecting piece 7 is located on the outside of the second pole through hole 31, that is, located on the lower surface of the lower bracket 3 beside the second pole through hole 31. This part of the connecting piece 7 abuts against the lower surface of the lower bracket 3. The connecting piece 7 is also connected to the pole 2, that is, the connecting piece 7 is connected to the pole 2 to form an integral structure, and the connecting piece 7 abuts against the lower surface of the lower bracket 3, thereby limiting the upward movement of the pole 2 through the connecting piece 7 to avoid the occurrence of upward dislocation of the pole 2.

[0072] Further, in this embodiment, please continue to refer to Fig.14 The connecting piece 7 is in the shape of a sheet, one end of which is in contact with the lower bracket 3, and the other end of which has an exposure hole 71 corresponding to the second pole through hole 31, which is used to expose the pole 2 after assembly, and the inner edge of the exposure hole 71 extends upward to form a ring-shaped inner edge portion 72, which is connected to the pole 2, for example, by welding. In this way, the pole 2 is reinforced by the fastening sheet to prevent it from dislocating upward.

[0073] This embodiment also provides a production process for a secondary battery cover plate structure, which is used to process the secondary battery cover plate structure as described above, and includes the following steps:

[0074] S01. Prepare suitable top cover plate 1, pole 2, lower bracket 3 and fixed cover 4 for use; specifically, use metal material to stamp out components such as top cover plate 1, pole 2 and fixed cover 4, and use mold injection molding to form lower bracket 3.

[0075] S02, such as Figure 5 As shown, the explosion-proof valve 8 is installed in the explosion-proof valve installation hole 13 of the top cover plate 1;

[0076] S03, such as Figure 7 As shown, the lower bracket 3 is connected to the top cover plate 1, specifically, the lower bracket 3 is connected to the top cover plate 1 through the buckle portion 32 of the lower bracket 3;

[0077] S04, such as Figure 8 As shown, the sealing member 6 is installed on the top cover plate 1. Specifically, the sealing member 6 is sleeved on the outer side of the buckle portion 32.

[0078] S05, such as Fig. 9 As shown, the pole 2 is installed in the first pole through hole 11 of the top cover plate 1;

[0079] S06, such as Fig.12 As shown, take the fixed cover 4 and install it on the top cover plate 1, so that the fixed cover 4 covers the welding boss 12 of the top cover plate 1, and weld from the position corresponding to the welding boss 12 on the upper surface of the fixed cover 4 to weld and fix the fixed cover 4 to the top cover plate 1;

[0080] S07, such as Fig.13 As shown, the integrated structure formed by the top cover plate 1, the seal 6, the pole 2 and the fixing frame is placed in a mold and the pole cap 5 is formed by injection molding on the outside of the pole 2; Fig.15 As shown, take the connecting piece 7 and install it on the side of the lower bracket 3 away from the top cover plate 1, so that part of the connecting piece 7 abuts against the lower bracket 3 and part is connected to the pole 2;

[0081] S08, marking the obtained top cover assembly, and attaching a protective film 9 to the explosion-proof valve 8, and then performing a helium test and an insulation withstand voltage test. After passing the test, the secondary battery cover plate structure is obtained.

[0082] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application.

[0083] For those skilled in the art, various other corresponding changes and deformations can be made according to the technical solutions and concepts described above, and all of these changes and deformations should fall within the protection scope of the claims of this application.

Claims

1. A secondary battery cover structure, characterized in that: include: A top cover plate having a first pole through hole penetrating along a thickness direction, wherein an upper surface of the top cover plate protrudes upwards at the periphery of the first pole through hole to form a welding boss; A pole, which is insulated and arranged on the top cover plate and located at the first pole through hole; A lower bracket, which has a second pole through hole penetrating along the thickness direction, the position of the second pole through hole corresponds to the position of the first pole through hole, and the top cover plate is arranged on the lower bracket and connected to the lower bracket; A fixed cover, which is made of metal material, has a third pole through hole penetrating along the thickness direction, and is arranged on the welding boss and welded to the welding boss; The pole cap is arranged around the outer side of the pole and is respectively connected with the top cover plate, the pole and the fixing cover.

2. The secondary battery cover structure according to claim 1, characterized in that: The fixing cover includes a welding portion and an outer edge portion perpendicular to the welding portion, a welding groove adapted to the welding boss is formed between the welding portion and the outer edge portion, the welding portion is welded to the welding boss, and the outer edge portion abuts against the outer side wall of the welding boss.

3. The secondary battery cover structure according to claim 1 or 2, characterized in that: The inner edge of the fixed cover is recessed inward to form a glue injection groove.

4. The secondary battery cover structure according to claim 1 or 2, characterized in that: The width of the welding portion is greater than the width of the welding boss, so that the inner edge of the welding portion extends to be located above the pole.

5. The secondary battery cover structure according to claim 1, characterized in that: The lower bracket is formed with a snap-on portion on the outer side of the second pole through-hole, and the upper end of the snap-on portion extends outward to form a snap-on outer edge, and a slot is formed between the snap-on outer edge and the upper surface of the lower bracket, and the height of the slot is adapted to the inner edge thickness of the first pole through-hole, and the top cover plate and the lower bracket are snap-on with each other through the snap-on outer edge.

6. The secondary battery cover structure according to claim 1, characterized in that: Also includes: A sealing member is arranged between the top cover plate and the pole and sleeved on the outer side of the buckle portion.

7. The secondary battery cover structure according to claim 6, characterized in that: Also includes: A connecting piece is arranged on a surface of the lower bracket away from the top cover plate, and at least a part of the connecting piece is located outside the second pole through hole and abuts against the lower bracket, and the connecting piece is also connected to the pole.

8. The secondary battery cover structure according to claim 7, characterized in that: The connecting piece is in a sheet shape, one end of which is in contact with the lower bracket, and the other end of which has an exposure hole corresponding to the second pole through hole. The inner edge of the exposure hole extends upward to form an inner edge portion, and the inner edge portion is connected to the pole.

9. A production process for a secondary battery cover plate structure, used for processing the secondary battery cover plate structure according to any one of claims 1 to 8, characterized in that: The following steps are involved: S01. Prepare suitable top cover plates, poles, lower brackets and fixed covers for standby use; S02. Take the explosion-proof valve and install it in the explosion-proof valve installation hole of the top cover plate; S03, connecting the lower bracket to the top cover plate; S04, take the sealing member and install it on the top cover plate; S05, inserting a pole into the first pole through hole of the top cover plate; S06. Take the fixed cover and install it on the top cover plate, so that the fixed cover covers the welding boss of the top cover plate, and weld from the position corresponding to the welding boss on the upper surface of the fixed cover to weld and fix the fixed cover to the top cover plate; S07, placing the integrated structure formed by the top cover plate, the seal, the pole and the fixing frame into a mold and injection molding the outside of the pole to form a pole cap; S08, marking the obtained top cover assembly, and attaching a protective film to the explosion-proof valve, and then performing a helium test and an insulation withstand voltage test. After passing the test, the secondary battery cover plate structure is obtained.

10. The production process of the secondary battery cover structure according to claim 9, characterized in that: Step S07 also includes: Take the connecting piece and install it on the side of the lower bracket away from the top cover plate, so that part of the connecting piece abuts against the lower bracket and part is connected to the pole.

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