Top cover structure of secondary battery

Abstract

The utility model relates to a top cover structure of a secondary battery. Relates to the technical field of new energy batteries. The cover plate specifically comprises a cover plate main body, lower plastic mounted on the inner side of the cover plate main body, and a sealing ring, upper plastic and a pole which are sequentially mounted on the outer side of the cover plate main body, the lower end of the pole extends along the inner side surface of the lower plastic, and the upper end of the pole extends along the outer side surface of the cover plate main body, so that the upper plastic and the sealing ring are tightly pressed on the cover plate main body. The lower end of the pole extends along the inner side surface of the lower plastic cement, and the upper end of the pole extends along the outer side surface of the cover plate main body, so that the upper plastic cement and the sealing ring are pressed on the cover plate main body while the pole is fixedly mounted on the cover plate main body and the lower plastic cement, and the extending height of the pole on the outer side of the cover plate main body can be effectively reduced; therefore, the space occupied by the pole is reduced, the energy density of the secondary battery is improved, and the mounting stability of the pole is ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to new energy battery technical field especially relates to a secondary battery top cover structure. BACKGROUND

[0002] Secondary battery (Rechargeable battery) refers to the battery that can be activated by the active material through the charging mode after the battery discharges and continues to use. The secondary battery generally includes the battery core, the battery shell containing the battery core, the top cover structure sealedly installed on the battery shell, the connecting sheet connecting the battery core and the top cover structure, and the electrolyte filled in the battery shell. The top cover structure includes the cover plate, the pole post installed on the cover plate, the lower plastic, the upper plastic, the sealing ring and the like. The pole post is connected with the tab of the battery core through the connecting sheet, and the pole post leads out the tab of the battery core to realize the charging and discharging function of the secondary battery.

[0003] In the prior art, the assembly of the top cover structure is usually that the cover plate, the pole post, the lower plastic, the upper plastic and the sealing ring of the top cover structure are respectively processed and then integrally assembled. When the pole post is fixedly installed on the cover plate, the pole post is usually fixedly connected with the cover plate through the welding mode on the outer side of the cover plate. Due to the welding requirement, the pole post needs to extend a certain height on the outer side of the cover plate, thereby causing that the pole post extending on the outer side of the cover plate occupies a large space, which is not conducive to increasing the energy density of the secondary battery and affects the stability of the installation of the pole post on the cover plate. UTILITY MODEL CONTENTS

[0004] The utility model aims at the deficiency of the prior art, and provides a secondary battery top cover structure, which can reduce the space occupation of the pole post, thereby improving the energy density of the secondary battery and ensuring the stability of the installation of the pole post.

[0005] The utility model provides a secondary battery top cover structure, which comprises a cover plate main body, a lower plastic installed on the inner side of the cover plate main body, a sealing ring, an upper plastic and a pole post installed on the outer side of the cover plate main body in sequence, wherein the lower end of the pole post extends along the inner side surface of the lower plastic, and the upper end of the pole post extends along the outer side surface of the cover plate main body to press the upper plastic and the sealing ring on the cover plate main body.

[0006] Further, the top cover structure further comprises an explosion-proof valve fixedly installed on the cover plate main body and a protection sheet arranged on the outer side of the explosion-proof valve, and the protection sheet is used for protecting the explosion-proof valve.

[0007] Further, the outer side of the cover plate main body is provided with a first sunken platform, the explosion-proof valve is provided with a protruding part, the protruding part is matched with the first sunken platform, and the explosion-proof valve is installed on the outer side of the cover plate main body.

[0008] Further, the explosion-proof valve is provided with a reinforcing rib for reinforcing the structural strength of the explosion-proof valve.

[0009] Further, the cover plate body is provided with a liquid injection hole for injecting liquid into the battery shell.

[0010] Further, the cover plate body is provided with a second sink communicating with the liquid injection hole, the second sink is arranged outside the liquid injection hole, and the top cover structure further comprises a sealing glue particle for sealing the liquid injection hole, the sealing glue particle is mounted on the second sink.

[0011] Further, the side surface of the second sink is a slope, and the outer peripheral surface of the sealing glue particle is a slope matched with the side surface of the second sink.

[0012] Further, the inner side surface of the cover plate body has a dovetail groove, and the lower plastic is formed on the inner side surface of the cover plate body in an injection molding manner and fills the dovetail groove to be connected with each other.

[0013] Further, the pole column comprises a pressing portion and a plug-in portion vertically extending on the pressing portion, the cross-sectional area of the pressing portion is greater than that of the plug-in portion, the plug-in portion extends along the inner side surface of the lower plastic after sequentially penetrating the sealing ring, the cover plate body and the lower plastic, and the pressing portion presses the upper plastic and the sealing ring on the cover plate body.

[0014] Further, the bottom of the plug-in portion is provided with a hollow hole for spin riveting the plug-in portion on the inner side surface of the lower plastic.

[0015] The secondary battery top cover structure has the following advantages:

[0016] (1) The top cover structure extends the lower end of the pole column along the inner side surface of the lower plastic and the upper end along the outer side surface of the cover plate body, so that the pole column is fixedly installed on the cover plate body and the lower plastic, and the upper plastic and the sealing ring are pressed on the cover plate body, thereby effectively reducing the height of the pole column extending outside the cover plate body, reducing the space occupied by the pole column, improving the energy density of the secondary battery, and ensuring the stability of the pole column installation.

[0017] (2) The cover plate body of the top cover structure can be made by stamping process, and after the cover plate body is stamped and formed, the lower plastic is formed on the inner side surface of the cover plate body 1 by injection molding process, so that when the top cover structure is assembled, the process of installing the lower plastic on the inner side of the cover plate body is reduced, the assembly of the top cover structure is more simple and convenient, easy to implement, and the production efficiency is improved.

[0018] (3) The inner side surface of the cover plate body of the top cover structure is provided with a dovetail groove, and when the lower plastic is formed on the inner side surface of the cover plate body through the injection molding process, the lower plastic is filled in the dovetail groove, so that the dovetail protrusion with the same profile as the dovetail groove is formed on the lower plastic, and the lower plastic is fixedly connected with the cover plate body through the dovetail protrusion filled in the dovetail groove;

[0019] (4) The outer side surface of the cover plate body of the top cover structure is provided with a first sunken platform, and the explosion-proof valve is provided with a protruding part, which is inserted and matched with the first sunken platform, so that the explosion-proof valve is more stably fixedly installed on the outer side of the cover plate body, thereby enhancing the stability of the top cover structure, and guiding the installation position of the explosion-proof valve on the outer side of the cover plate body, thereby further simplifying the assembly of the top cover structure, facilitating implementation, and further improving the production efficiency;

[0020] (5) The explosion-proof valve of the top cover structure is distributed with reinforcing ribs, which strengthen the structural strength of the explosion-proof valve, so that the explosion-proof valve on the top cover structure can better protect the secondary battery, and further enhance the safety performance of the secondary battery;

[0021] (6) The second sunken platform is arranged on the outer side of the liquid injection hole of the top cover structure and is used for installing the sealing rubber particle, which is used for simplifying the installation of the sealing rubber particle, thereby simplifying the assembly of the top cover structure, facilitating implementation, and further improving the production efficiency, and the cooperation between the second sunken platform and the sealing rubber particle can stably install the sealing rubber particle on the cover plate body and prevent the sealing rubber particle from falling into the battery shell and damaging the connecting piece, thereby causing internal short circuit of the battery cell;

[0022] (7) The side surface of the second sunken platform of the top cover structure is provided with an inclined surface, which guides the electrolyte, so that the injected electrolyte can be better collected to the liquid injection hole, the electrolyte can be prevented from diffusing to the surrounding, the injection efficiency is improved, the injection pressure can be buffered, the internal structural members such as the connecting piece and the tab of the battery cell are prevented from being washed away due to large injection pressure, the performance failure of the internal structural members of the battery cell is avoided, and the safety performance of the secondary battery is ensured;

[0023] (8) The outer peripheral surface of the sealing rubber particle of the top cover structure is an inclined surface matched with the side surface of the second sunken platform, so that when the sealing rubber particle is fixedly installed on the second sunken platform, the inclined surface of the outer peripheral surface of the sealing rubber particle is matched with the inclined surface of the side surface of the second sunken platform, the contact area between the sealing rubber particle and the second sunken platform is increased, the installation of the sealing rubber particle in the second sunken platform is more stable, and the stability of the top cover structure is further enhanced;

[0024] (9) The top cover structure sets a hollow hole at the bottom of the plug-in part of the pole, extends the bottom of the plug-in part on the inner surface of the lower plastic by the way of spin riveting, realizes the fixed installation of the pole on the cover plate body and the lower plastic, thus can effectively reduce the height of the pole extending outside the cover plate body, and reduce the weight of the pole, thereby reducing the space occupied by the pole, reducing the weight of the top cover structure, and further facilitating to improve the capacity of the secondary battery and increase the energy density of the secondary battery. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate an embodiment of the present application and, together with the description, serve to explain the principles of the present application. In these drawings, like reference numerals are used to represent similar elements.

[0026] Fig. 1 It is an assembly explosion view of the pole and the cover plate body of the secondary battery top cover structure before spin riveting of the embodiment of the present application;

[0027] Fig. 2 It is a partial cross-sectional schematic view of the pole and the cover plate body of the secondary battery top cover structure after spin riveting of the embodiment of the present application;

[0028] Fig. 3 It is a structural schematic view of the cover plate body of the secondary battery top cover structure of the embodiment of the present application;

[0029] Fig. 4 It is a structural schematic view of the lower plastic of the secondary battery top cover structure of the embodiment of the present application;

[0030] Fig. 5 It is a structural schematic view of the explosion-proof valve of the secondary battery top cover structure of the embodiment of the present application;

[0031] Fig. 6 It is a structural schematic view of the pole of the secondary battery top cover structure of the embodiment of the present application.

[0032] In the figure: 1, cover plate body; 11, dovetail groove; 12, first sink; 13, liquid injection hole; 14, second sink; 2, lower plastic; 21, dovetail protrusion; 3, sealing ring; 4, upper plastic; 5, pole; 51, compression part; 52, plug-in part; 521, hollow hole; 6, explosion-proof valve; 61, protrusion; 62, reinforcing rib; 7, protective sheet. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical scheme and advantages of the utility model embodiment clearer, the technical scheme in the utility model embodiment will be clearly and completely described below in combination with the drawings in the utility model embodiment. All other embodiments obtained by the person skilled in the art without creative labor based on the embodiments in the utility model belong to the protection scope of the utility model.

[0034] Please refer to Figs. 1-6 The utility model discloses a secondary battery top cover structure, including the cover plate main part 1, install the lower plastic 2 in the inside of cover plate main part 1, and the sealing ring 3, upper plastic 4 and pole 5 are installed in the outside of cover plate main part 1 in proper order, the lower end of pole 5 extends along the inside surface of lower plastic 2, and the upper end extends along the outside surface of cover plate main part 1 to press upper plastic 4 and sealing ring 3 on cover plate main part 1.

[0035] In the application, the top cover structure includes the cover plate main part 1, the lower plastic 2, the sealing ring 3, the upper plastic 4 and the pole 5, the lower plastic 2 is installed on the inside of the cover plate main part 1, the sealing ring 3, the upper plastic 4 and the pole 5 are installed on the outside of the cover plate main part 1 in proper order, thereby insulating the connecting piece and the cover plate main part 1 through the lower plastic 2, insulating the pole 5 and the cover plate main part 1 through the upper plastic 4, preventing the cover plate main part 1 from being electrified and affecting the use of the secondary battery. The sealing ring 3 seals the gap between the pole 5 and the cover plate main part 1, thereby preventing the electrolyte in the shell from leaking from the gap between the pole 5 and the cover plate main part 1, and further ensuring the safety performance of the secondary battery.

[0036] In the application, when assembling the top cover structure, the lower end of the pole 5 extends along the inside surface of the lower plastic 2, and the upper end extends along the outside surface of the cover plate main part 1, so that the pole 5 is fixedly installed on the cover plate main part 1 and the lower plastic 2, and the upper plastic 4 and the sealing ring 3 are pressed on the cover plate main part 1, thereby effectively reducing the height of the pole 5 extending outside the cover plate main part 1, further reducing the space occupied by the pole 5, improving the energy density of the secondary battery, and ensuring the stability of the installation of the pole 5.

[0037] Specifically, in the embodiment, the cover plate main part 1 can be made by stamping process. After the cover plate main part 1 is stamped and formed, the lower plastic 2 is formed on the inside surface of the cover plate main part 1 by injection molding process, so that when assembling the top cover structure, the process of installing the lower plastic 2 on the inside of the cover plate main part 1 is reduced, the assembly of the top cover structure is more simple and convenient, easy to implement, and the production efficiency is further improved.

[0038] Further, in the embodiment, the inner side surface of the cover plate body 1 is provided with dovetail grooves 11, when the lower plastic 2 is formed on the inner side surface of the cover plate body 1 through the injection molding process, the lower plastic 2 is filled in the dovetail grooves 11, so that the dovetail protrusions 21 with the same profile as the dovetail grooves 11 are formed on the lower plastic 2, the lower plastic 2 is fixedly connected with the cover plate body 1 through the dovetail protrusions 21 filled in the dovetail grooves 11, so that when the assembly of the top cover structure is performed, the process of installing the lower plastic 2 on the inner side of the cover plate body 1 is reduced, the assembly of the top cover structure is more simple and convenient, easy to implement, and the production efficiency is further improved.

[0039] In the present application, since the cover plate body 1 is used to close the opening of the battery shell, the side of the cover plate body 1 close to the battery shell is regarded as the inner side, and the side of the cover plate body 1 away from the battery shell is regarded as the outer side. The "outer side" and "inner side" mentioned throughout the text are based on this.

[0040] In the embodiment, the top cover structure further comprises an explosion-proof valve 6 fixedly installed on the cover plate body 1, and a protective sheet 7 arranged outside the explosion-proof valve 6, the protective sheet 7 is used to protect the explosion-proof valve 6. In the present application, the top cover structure further comprises an explosion-proof valve 6 installed on the cover plate body 1, when the battery shell is overcharged, a large amount of gas is generated in the battery shell, the internal pressure of the battery shell is increased, at this time, the gas in the battery shell can act on the explosion-proof valve 6, and the gas is released through the explosion-proof valve 6, so as to reduce the internal pressure of the battery shell and prevent the secondary battery from exploding and causing safety accidents.

[0041] In the present application, the top cover structure further comprises a protective sheet 7 arranged outside the explosion-proof valve 6, so that the explosion-proof valve 6 is protected by the protective sheet 7, the explosion-proof valve 6 is prevented from being damaged by sharp objects and affecting the use of the explosion-proof valve 6, and foreign matter, dust and the like are also prevented from falling into the explosion-proof valve 6 and affecting the use of the explosion-proof valve 6, so that the safety performance of the top cover structure is better, the practicality is stronger, and the service life of the secondary battery is further guaranteed.

[0042] In the embodiment, the outer side surface of the cover plate body 1 is provided with a first sunken platform 12, and the explosion-proof valve 6 is provided with a protruding part 61, when the explosion-proof valve 6 is installed on the cover plate body 1, the protruding part 61 on the explosion-proof valve 6 is first inserted and matched with the first sunken platform 12 on the outer side surface of the cover plate body 1, and then the explosion-proof valve 6 is fixedly connected with the cover plate body 1, so as to complete the fixed installation of the explosion-proof valve 6 on the outer side of the cover plate body 1.

[0043] Through the plug-in cooperation of the convex part 61 and the first sink 12, on the one hand, the fixed installation of the explosion-proof valve 6 outside the cover plate body 1 is more stable, thereby enhancing the stability of the top cover structure; on the other hand, the installation position of the explosion-proof valve 6 outside the cover plate body 1 is guided, thereby further making the assembly of the top cover structure more simple and convenient, easy to implement, and thereby improving the production efficiency.

[0044] Specifically, in actual implementation, the welding mode can be used for the fixed connection of the explosion-proof valve 6 and the protective sheet 7 with the cover plate body 1. It can be predicted that when the welding mode is used for the fixed connection of the explosion-proof valve 6 and the protective sheet 7 with the cover plate body 1, in the present application, the explosion-proof valve 6 and the protective sheet 7 are fixed outside the cover plate body 1, which can also avoid the falling of welding slag into the inside of the battery shell, and is beneficial to improving the safety performance of the secondary battery.

[0045] In the embodiment, the reinforcing ribs 62 are distributed on the explosion-proof valve 6, and the structural strength of the explosion-proof valve 6 is strengthened through the reinforcing ribs 62, so that the explosion-proof valve 6 on the top cover structure can better protect the secondary battery, and further enhance the safety performance of the secondary battery.

[0046] Since after the battery shell is closed through the top cover structure in the manufacturing process of the secondary battery, the electrolyte needs to be injected into the battery shell, in the embodiment, the injection hole 13 is arranged on the cover plate body 1, and after the cover plate body 1 is fixedly connected with the battery shell and the battery shell is closed, the injection hole 13 communicates the inside of the battery shell with the outside, so that the electrolyte can be injected into the battery shell through the injection hole 13, the electrolyte can immerse the battery cell in the battery shell, and the normal use of the secondary battery is ensured.

[0047] In the embodiment, the second sink 14 which communicates with the injection hole 13 is arranged on the cover plate body 1, the second sink 14 is arranged outside the injection hole 13, the top cover structure further comprises a sealing rubber particle for sealing the injection hole 13, and the sealing rubber particle is installed on the second sink 14. After the injection of the electrolyte of the secondary battery is completed, the injection hole 13 needs to be closed, so as to prevent the electrolyte in the battery shell from leaking, and the safety performance of the secondary battery is ensured.

[0048] Therefore, in the present application, the top cover structure further comprises a sealing rubber particle, the second sink 14 is arranged on the cover plate body 1, the second sink 14 communicates with the injection hole 13 and is located outside the injection hole 13, and after the injection of the secondary battery is completed, the sealing rubber particle is fixedly installed on the second sink 14, so that the sealing rubber particle seals the injection hole 13 and prevents the electrolyte in the battery shell from leaking.

[0049] In the prior art, the sealing glue particles are usually arranged on the inner side of the cover plate body 1, and in the present application, the second sink 14 is arranged on the outer side of the liquid injection hole 13 for mounting the sealing glue particles. On the one hand, this makes the mounting of the sealing glue particles simple and convenient, thereby making the assembly of the top cover structure simpler and more convenient and easy to implement, and further improving the production efficiency. On the other hand, through the cooperation of the second sink 14 and the sealing glue particles, the mounting of the sealing glue particles on the cover plate body 1 is more stable, and the sealing glue particles can be prevented from falling into the battery shell and damaging the connecting piece, thereby causing internal short circuit of the battery cell.

[0050] Further, in the present embodiment, the side surface of the second sink 14 is arranged as an inclined surface. Since the second sink 14 is arranged on the outer side of the liquid injection hole 13 and communicates with the outside, when the secondary battery is injected with electrolyte, the electrolyte enters the inside of the battery shell after sequentially flowing through the second sink 14 and the liquid injection hole 13.

[0051] In the present application, the side surface of the second sink 14 is arranged as an inclined surface, and the electrolyte is guided through the inclined surface of the second sink 14. This not only makes the injected electrolyte better converge towards the liquid injection hole 13, prevents the electrolyte from spreading in all directions, thereby improving the injection efficiency, but also buffers the injection pressure, prevents the internal structural members such as the tab and the connecting piece of the battery cell from being washed away due to the large injection pressure, avoids performance failure of the internal structural members of the battery cell, and thereby ensures the safety performance of the secondary battery.

[0052] In the present application, the outer peripheral surface of the sealing glue particle is an inclined surface matched with the side surface of the second sink 14. Therefore, when the sealing glue particle is fixedly mounted on the second sink 14, the inclined surface of the outer periphery of the sealing glue particle cooperates with the inclined surface of the side surface of the second sink 14, which can increase the contact area between the sealing glue particle and the second sink 14, thereby making the mounting of the sealing glue particle in the second sink 14 more stable and further enhancing the stability of the present top cover structure.

[0053] In the present embodiment, the pole 5 includes a compression part 51 and a plug-in part 52 vertically extending on the compression part 51. The cross-sectional area of the compression part 51 is larger than that of the plug-in part 52. The plug-in part 52 extends along the inner side surface of the lower plastic 2 after sequentially penetrating the sealing ring 3, the cover plate body 1 and the lower plastic 2. The compression part 51 compresses the upper plastic 4 and the sealing ring 3 on the cover plate body 1.

[0054] In the application, the pole column 5 comprises a pressing part 51 and a plug-in part 52, the plug-in part 52 extends inside the pressing part 51, and the cross-sectional area of the pressing part 51 is larger than that of the plug-in part 52. When assembling the top cover structure, on the outside of the cover plate body 1, the sealing ring 3 is first installed on the cover plate body 1, then the upper plastic 4 is installed on the cover plate body 1, so that the upper plastic 4 is located at the periphery of the sealing ring 3, then the plug-in part 52 of the pole column 5 is sequentially penetrated through the sealing ring 3, the cover plate body 1 and the lower plastic 2, and finally the bottom of the plug-in part 52 extends on the inside surface of the lower plastic 2, so that the pole column 5 is fixedly installed on the cover plate body 1 and the lower plastic 2, and at the same time, the pressing part 51 of the pole column 5 abuts against the upper plastic 4 and the sealing ring 3, thereby fixing the upper plastic 4 and the sealing ring 3 on the cover plate body 1.

[0055] Specifically, in the embodiment, the plug-in part 52 of the pole column 5 is fixedly connected with the cover plate body 1 by means of spin riveting. The plug-in part 52 is provided with a hollow hole 521 at the bottom, after being sequentially penetrated through the sealing ring 3, the cover plate body 1 and the lower plastic 2, the bottom of the plug-in part 52 is spin riveted along the outer periphery of the hollow hole 521 by means of spin riveting equipment, so that the bottom of the plug-in part 52 extends on the inside surface of the lower plastic 2, thereby forming a U-shaped bayonet between the plug-in part 52 and the pressing part 51, the upper end of the U-shaped bayonet is located on the outside of the cover plate body 1, and the lower end is located on the inside of the lower plastic 2, thereby realizing the fixed installation of the pole column 5 on the cover plate body 1 and the lower plastic 2.

[0056] Compared with the prior art, when the pole column is fixedly installed on the cover plate, the pole column is usually fixedly connected with the cover plate on the outside of the cover plate by means of welding, and the pole column needs to extend a certain height on the outside of the cover plate due to the requirement of welding, thereby resulting in that the pole column extending on the outside of the cover plate occupies a large space, which is not conducive to increasing the energy density of the secondary battery, and affects the stability of the installation of the pole column on the cover plate.

[0057] In the application, the bottom of the plug-in part 52 of the pole column 5 is extended on the inside surface of the lower plastic 2 by means of spin riveting through the hollow hole 521 arranged at the bottom of the plug-in part 52, thereby realizing the fixed installation of the pole column 5 on the cover plate body 1 and the lower plastic 2, so that the height of the pole column 5 extending on the outside of the cover plate body 1 can be effectively reduced, and the weight of the pole column 5 can be reduced, thereby reducing the space occupied by the pole column 5 and the weight of the top cover structure, and thereby being conducive to improving the capacity of the secondary battery and increasing the energy density of the secondary battery.

[0058] The above-described content can be implemented individually or in various combinations, and these variants are within the protection scope of the utility model.

[0059] It is to be noted that, in the present text, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element preceded by "comprises... a" does not, without more constraints, foreclose the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0060] Finally, it should be noted that the above embodiments are merely used to illustrate the technical solutions of the present application, rather than limiting it. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A secondary battery top cover structure, characterized in that: The top cover structure comprises a cover plate body (1), a lower plastic (2) mounted on the inner side of the cover plate body (1), a sealing ring (3), an upper plastic (4) and a pole (5) mounted on the outer side of the cover plate body (1) in sequence; the lower end of the pole (5) extends along the inner side surface of the lower plastic (2), and the upper end extends along the outer side surface of the cover plate body (1) to press the upper plastic (4) and the sealing ring (3) on the cover plate body (1).

2. A secondary battery top cover structure as defined in claim 1, wherein: The top cover structure further comprises an explosion-proof valve (6) fixedly mounted on the cover plate body (1), and a protective sheet (7) arranged on the outer side of the explosion-proof valve (6), which is used to protect the explosion-proof valve (6).

3. A secondary battery top cover structure as defined in claim 2, wherein: The outer side surface of the cover plate body (1) is provided with a first sunken platform (12), and the explosion-proof valve (6) is provided with a protruding part (61), which cooperates with the first sunken platform (12) to mount the explosion-proof valve (6) on the outer side of the cover plate body (1).

4. A secondary battery top cover structure as defined in claim 2, wherein: The explosion-proof valve (6) is provided with a reinforcing rib (62) for strengthening the structural strength of the explosion-proof valve (6).

5. A secondary battery top cover structure as defined in claim 1, wherein: The cover plate body (1) is provided with a liquid injection hole (13) for injecting liquid into the battery shell.

6. A secondary battery top cover structure as defined in claim 5, wherein: The cover plate body (1) is provided with a second sunken platform (14) in communication with the liquid injection hole (13), and the second sunken platform (14) is arranged on the outer side of the liquid injection hole (13). The top cover structure further comprises a sealing rubber particle for sealing the liquid injection hole (13), and the sealing rubber particle is mounted on the second sunken platform (14).

7. A secondary battery top cover structure as defined in claim 6, wherein: The side surface of the second sunken platform (14) is a bevel surface, and the outer peripheral surface of the sealing rubber particle is a bevel surface matched with the side surface of the second sunken platform (14).

8. A top cover structure for a secondary battery as defined in claim 1, wherein: The inner side surface of the cover plate body (1) has a dovetail groove (11), and the lower plastic (2) is formed on the inner side surface of the cover plate body (1) in an injection molding manner and fills the dovetail groove (11) to be connected to each other.

9. A top cover structure for a secondary battery as defined in claim 1, wherein: The pole (5) comprises a pressing part (51) and a plug-in part (52) vertically extending on the pressing part (51), the cross-sectional area of the pressing part (51) is greater than that of the plug-in part (52), the plug-in part (52) extends along the inner side surface of the lower plastic (2) after penetrating the sealing ring (3), the cover plate body (1) and the lower plastic (2) in sequence, and the pressing part (51) presses the upper plastic (4) and the sealing ring (3) on the cover plate body (1).

10. A secondary battery top cover structure as defined in claim 9, wherein: The bottom of the plug-in part (52) is provided with a hollow hole (521) for spin riveting the plug-in part (52) on the inner side surface of the lower plastic (2).

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