CN220368015U

CN220368015U - Cover plate structure

Info

Publication number: CN220368015U
Application number: CN202321972874.4U
Authority: CN
Inventors: 王贝; 田安; 黄曲; 徐彤; 曾吉鸿
Original assignee: Cornex New Energy Co ltd
Current assignee: Cornex New Energy Co ltd
Priority date: 2023-07-26
Filing date: 2023-07-26
Publication date: 2024-01-19
Anticipated expiration: 2033-07-26

Abstract

The utility model relates to and discloses a cover plate structure. Relates to the technical field of batteries. The explosion-proof valve comprises a cover plate body, an explosion-proof hole arranged on the cover plate body and an explosion-proof valve arranged on the outer side of the explosion-proof hole; the explosion-proof hole is internally provided with a fixed platform, the explosion-proof valve is fixed on the outer side of the fixed platform, and the fixed platform is provided with a liquid injection channel for injecting electrolyte. The liquid injection channel is arranged in the explosion-proof hole, and after liquid injection is finished, the explosion-proof valve can be fixed on the outer side of the fixed platform in a welding mode and the like, so that the liquid injection channel is isolated from the outside, and electrolyte is prevented from flowing out of the box body of the battery module through the liquid injection channel, the process of carrying out laser welding on the liquid injection channel and sealing the liquid injection channel is reduced, the condition that a battery product is unqualified due to the welding process is further reduced, and the production reject ratio of the battery is reduced.

Description

Cover plate structure

Technical Field

The utility model relates to the technical field of batteries, in particular to a cover plate structure.

Background

The power battery is a core part of a new energy automobile, and in the field of the new energy automobile, a plurality of single battery cores are generally assembled into a battery module, and then the battery module is assembled into a battery pack (namely, the power battery). The battery module generally adopts a square hard shell structure, and the battery module comprises a box body and a cover plate, wherein the box body and the cover plate can provide a closed space for accommodating a plurality of single battery cells, and the single battery cells are electrically connected with each other.

The cover plate structure of the battery is provided with a liquid injection hole and an explosion-proof valve, wherein the liquid injection hole is used for injecting electrolyte, and the explosion-proof valve mainly serves as a pressure relief opening for gas generated in the working process of the battery and prevents the explosion of the battery. In the cover plate structure of the traditional battery, the liquid injection hole and the explosion-proof valve are separately designed, laser welding is needed to be carried out on the liquid injection hole after liquid injection is completed, the liquid injection hole is sealed, and the explosion-proof valve is usually fixed on the cover plate in a welding mode. Since various conditions such as a burst spot, a pit, a bulge, and a defective welding depth are easily generated in welding, the more the welding process is, the more defective batteries are easily generated in the production process of the batteries, and thus the defective rate of the batteries is increased, resulting in a large amount of waste of the batteries.

Disclosure of Invention

The present utility model has been made in view of the above-described drawbacks of the related art, and an object of the present utility model is to provide a cover plate structure capable of reducing the number of welding steps of a battery and reducing the production failure rate of the battery.

The utility model provides a cover plate structure, which comprises a cover plate main body, explosion-proof holes arranged on the cover plate main body, and explosion-proof valves arranged on the outer sides of the explosion-proof holes; the explosion-proof valve is characterized in that a fixed platform is arranged in the explosion-proof hole, the explosion-proof valve is fixed on the outer side of the fixed platform, and a liquid injection channel for injecting electrolyte is arranged on the fixed platform.

Further, the cover plate structure further comprises an explosion-proof valve film fixed on the cover plate main body, and the explosion-proof valve film is arranged on the outer side of the explosion-proof valve.

Further, a positive pole used for guiding out the positive pole of the battery cell and a negative pole used for guiding out the negative pole of the battery cell are arranged on the cover plate main body.

Further, the positive pole comprises a first outer connecting part and a first inner connecting part, wherein the first outer connecting part is connected with an outer circuit, and the first inner connecting part is connected with a positive pole lug of the battery cell.

Further, the positive electrode post further includes a first sealing ring disposed between the cover plate main body and the first outer connecting portion, where the first sealing ring isolates the first outer connecting portion and the first inner connecting portion from the cover plate main body.

Further, the positive pole is still including locating mould board and second down under moulding the inboard of apron main part, mould board and second down and mould the board and locate respectively first internal connection portion both sides, mould the board and be used for spacing the electric core under the first, the second mould the board under and be used for with the positive pole tab of electric core with the apron main part is isolated.

Further, the negative pole post comprises a second outer connecting part and a second inner connecting part, wherein the second outer connecting part is connected with an outer circuit, and the second inner connecting part is connected with a negative pole lug of the battery cell.

Further, the negative electrode post further comprises a second sealing ring arranged between the cover plate main body and the second outer connecting portion, and the second sealing ring isolates the second outer connecting portion and the second inner connecting portion from the cover plate main body.

Further, the negative pole post is still including locating mould board and fourth down mould the board under the inboard third of apron main part, mould the board under the third and mould the board under the fourth and locate respectively second internal connection portion both sides, mould the board under the third and be used for spacing the electric core, the fourth mould the board under be used for with the negative pole utmost point ear of electric core with the apron main part is isolated.

Further, the inner side of the fixed platform is flush with the inner side of the cover plate main body, and the fixed platform and the cover plate main body are of an integrated structure.

The cover plate structure has the following gain effects:

(1) The liquid injection channel of the cover plate structure is arranged in the explosion-proof hole, after liquid injection is completed, the explosion-proof valve can be fixed on the outer side of the fixed platform in a welding mode and the like, the liquid injection channel is isolated from the outside, and electrolyte is prevented from flowing out of the box body of the battery module through the liquid injection channel, so that the process of carrying out laser welding on the liquid injection channel is reduced, the process of sealing the liquid injection channel is reduced, the condition that a battery product is unqualified due to a welding process is further reduced, and the production reject ratio of the battery is reduced;

(2) The explosion-proof valve film is arranged on the outer side of the explosion-proof valve of the cover plate structure, so that the explosion-proof valve can be protected, sharp objects are prevented from damaging the explosion-proof valve, the use of the explosion-proof valve is influenced, foreign matters, dust and the like can be prevented from falling into the explosion-proof valve, the appearance of a battery is influenced, and the cover plate structure is higher in practicability;

(3) The cover plate main body of the cover plate structure is provided with a positive pole column and a negative pole column, one part of the positive pole column is positioned in the closed space and is electrically connected with a positive pole lug of the battery cell in the closed space, and the other part of the positive pole column is positioned outside the closed space and is connected with an external circuit, so that the positive pole of the battery cell is led out; one part of the negative pole post is positioned in the closed space and is electrically connected with the negative pole lug of the battery cell in the closed space, and the other part of the negative pole post is positioned outside the closed space and is connected with an external circuit, so that the negative pole of the battery cell is led out;

(4) The periphery of the first outer connecting part and the first inner connecting part of the cover plate structure is provided with the first sealing ring, on one hand, the first sealing ring can seal the first outer connecting part and the first inner connecting part, and gaps are prevented from being formed between the first outer connecting part and the inner wall of the through hole and between the first inner connecting part and the inner wall of the through hole, so that the battery has better tightness; on the other hand, an insulating zone can be formed between the first outer connecting part and the cover plate main body and between the first inner connecting part and the cover plate main body, so that the battery has better insulating effect;

(5) The positive pole post of the cover plate structure further comprises a first lower plastic plate and a second lower plastic plate, wherein the first lower plastic plate limits the battery cell in the box body, so that the battery cell is prevented from moving in the battery module after the battery module is installed, the second lower plastic plate isolates the positive pole lug of the battery cell from the cover plate main body, and the positive pole lug of the battery cell is prevented from being in contact with the cover plate main body to form a short circuit, so that the service performance of the battery is ensured;

(6) The fixing platform of the cover plate structure and the cover plate main body are of an integrated structure, so that the structural strength of the cover plate main body is enhanced, and the stability of the battery structure is guaranteed; on the other hand, when the explosion-proof valve is welded on the fixed platform, the stability of the connection between the explosion-proof valve and the cover plate main body can be further enhanced;

(7) The inner side of the fixed platform of the cover plate structure is flush with the inner side of the cover plate main body, a groove is formed between the outer side of the fixed platform and the outer side of the cover plate main body, and the explosion-proof valve is welded in the groove, so that the explosion-proof valve is prevented from forming a bulge on the outer side surface of the cover plate main body to influence the appearance of the battery; on the other hand seals the recess through explosion-proof valve pad pasting, can carry out better protection to the explosion-proof valve in the recess, guarantees the result of use of battery.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the utility model and together with the description, serve to explain the principles of the utility model. In the drawings, like reference numerals are used to identify like elements.

FIG. 1 is a schematic cross-sectional view of a cover plate structure according to an embodiment of the present utility model;

fig. 2 is a schematic structural view of an explosion-proof hole of a cover plate structure according to an embodiment of the utility model.

In the figure: 1. a cover plate main body; 2. a positive electrode post; 21. a first external connection portion; 22. a first inner connection; 23. a first seal ring; 24. a first lower plastic plate; 25. a second lower plastic plate; 3. a negative electrode column; 31. a second external connection portion; 32. a second inner connection; 33. a second seal ring; 34. a third lower plastic plate; 35. a fourth lower plastic plate; 4. explosion-proof holes; 41. a fixed platform; 42. a liquid injection channel; 5. an explosion-proof valve; 6. and (5) sticking a film on the explosion-proof valve.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model, and all other embodiments obtained by those skilled in the art without making any creative effort based on the embodiments of the present utility model are included in the protection scope of the present utility model.

Referring to fig. 1-2, a cover structure according to an embodiment of the present utility model includes a cover body 1, an explosion-proof hole 4 provided on the cover body 1, and an explosion-proof valve 5 provided outside the explosion-proof hole 4; the explosion-proof hole 4 is provided with a fixed platform 41, the explosion-proof valve 5 is fixed on the outer side of the fixed platform 41, and the fixed platform 41 is provided with a liquid injection channel 42 for injecting electrolyte.

In this application, the apron structure includes apron main part 1, and when apron main part 1 closed the box of battery module, constitutes the airtight space that holds a plurality of monomer electric core with the box. The cover plate main body 1 is provided with an explosion-proof hole 4, a fixed platform 41 is arranged in the explosion-proof hole 4, and a liquid injection channel 42 is arranged on the fixed platform 41. In the battery production process, electrolyte is injected into the box body of the battery module through the liquid injection channel 42, so that the electrolyte is filled in the periphery of the battery cell in the box body. After the injection is completed, the explosion-proof valve 5 is fixed at the outer side of the fixed platform 41, so that the explosion-proof valve 5 isolates the injection channel 42 from the outside, and the electrolyte is prevented from flowing out of the box body of the battery module through the injection channel 42.

When the battery cell in the battery module is overcharged, a large amount of gas is generated in the box body of the battery module, so that the internal pressure of the box body is increased, the gas in the box body can act on the explosion-proof valve 5 through the liquid injection channel 42, and the gas is released through the explosion-proof valve 5, so that the internal pressure of the box body is reduced, explosion of the battery is prevented, and safety accidents are caused.

Because in this application, annotate liquid passageway 42 setting in explosion-proof hole 4, annotate the liquid after accomplishing, explosion-proof valve 5 accessible mode such as welding is fixed in the outside of fixed platform 41, and with annotating liquid passageway 42 and external isolated, prevent that electrolyte from flowing out battery module's box through annotating liquid passageway 42 to reduce annotating liquid passageway 42 and carry out laser welding, with annotating the sealed process of liquid passageway 42, and then reduce the unqualified condition of battery product because of the welding process leads to, reduce the production defective rate of battery.

In this embodiment, the cover structure further includes an explosion-proof valve film 6 fixed on the cover main body 1, and the explosion-proof valve film 6 is disposed outside the explosion-proof valve 5. The cover plate structure further comprises an explosion-proof valve film 6, after the explosion-proof valve 5 is fixed on the fixing platform 41 in a welding mode or the like, the explosion-proof valve film 6 is fixed on the cover plate main body 1 in an adhesive mode or the like, and the explosion-proof valve film 6 is positioned on the outer side of the explosion-proof valve 5. The explosion-proof valve film 6 is arranged on the outer side of the explosion-proof valve 5, so that the explosion-proof valve 5 is protected, sharp objects are prevented from damaging the explosion-proof valve 5, the use of the explosion-proof valve 5 is affected, foreign matters, dust and the like can be prevented from falling into the explosion-proof valve 5, the appearance of a battery is affected, and the practicability of the cover plate structure is higher.

In this embodiment, the cover body 1 is provided with a positive electrode post 2 for guiding out the positive electrode of the battery cell and a negative electrode post 3 for guiding out the negative electrode of the battery cell. When the cover plate main body 1 seals the box body of the battery module, a closed space for accommodating a plurality of single battery cells is formed by the cover plate main body and the box body. The cover plate main body 1 is provided with a positive pole 2 and a negative pole 3, one part of the positive pole 2 is positioned in the closed space and is electrically connected with a positive pole lug of the battery cell in the closed space, and the other part of the positive pole 2 is positioned outside the closed space and is connected with an external circuit, so that the positive pole of the battery cell is led out; one part of the negative pole column 3 is positioned in the closed space and is electrically connected with a negative pole lug of the battery cell in the closed space, and the other part of the negative pole column is positioned outside the closed space and is connected with an external circuit, so that the negative pole of the battery cell is led out.

In this embodiment, the positive electrode post 2 includes a first external connection portion 21 and a first internal connection portion 22, the first external connection portion 21 is connected to an external circuit, and the first internal connection portion 22 is connected to a positive electrode tab of the battery cell. The positive pole 2 arranged on the cover plate main body 1 comprises a first outer connecting part 21 and a first inner connecting part 22, one end of the first outer connecting part 21 is positioned in the cover plate main body 1, the other end extends out of the cover plate main body 1, one end of the first inner connecting part 22 is positioned in the cover plate main body 1, and the other end extends into the inner side of the cover plate main body 1. The first outer connecting part 21 is located at one end in the cover plate main body 1 and is connected with one end of the first inner connecting part 22 located in the cover plate main body 1, one end of the first outer connecting part 21 extending out of the cover plate main body 1 is connected with an outer circuit, and one end of the first inner connecting part 22 extending into the inner side of the cover plate main body 1 is electrically connected with a positive electrode lug of the battery cell.

Because aluminum has good chemical properties, electrical conductivity and workability, and is well suited for use as a positive electrode material, aluminum foil is generally used as a positive electrode tab material of a battery cell during the production process of the battery, and therefore, in the present application, the first inner connection portion 22 may be made of an aluminum material, so that the first inner connection portion 22 has better electrical conductivity when electrically connected to the positive electrode tab of the battery cell. The first external connection part 21 may also be made of an aluminum material, so that the first external connection part 21 has good conductivity when electrically connected to an external circuit, thereby ensuring the performance of the battery.

In this embodiment, the positive electrode post 2 further includes a first sealing ring 23 disposed between the cover main body 1 and the first outer connecting portion 21, and the first sealing ring 23 isolates the first outer connecting portion 21 and the first inner connecting portion 22 from the cover main body 1. The positive electrode post 2 further includes a first seal ring 23, and the first seal ring 23 is provided on the outer periphery of the first outer connection portion 21 and the first inner connection portion 22 to isolate the first outer connection portion 21 and the first inner connection portion 22 from the cap plate main body 1.

It is envisioned that: the cover plate main body 1 is provided with a through hole, one end of the first external connection part 21 is positioned in the through hole, the other end extends out of the through hole at the outer side of the cover plate main body 1, one end of the first internal connection part 22 is positioned in the through hole, and the other end extends out of the through hole at the inner side of the cover plate. The first sealing ring 23 is used for sealing the first outer connecting part 21 and the first inner connecting part 22, so that gaps are prevented between the first outer connecting part 21 and the first inner connecting part 22 and the inner wall of the through hole, and the battery has better sealing performance; on the other hand, an insulating region is formed between the first outer and inner connection parts 21 and 22 and the cap body 1, so that the battery has a better insulating effect.

In this embodiment, the positive electrode post 2 further includes a first lower plastic plate 24 and a second lower plastic plate 25 disposed on the inner side of the cover main body 1, the first lower plastic plate 24 and the second lower plastic plate 25 are disposed on two sides of the first inner connecting portion 22, the first lower plastic plate 24 is used for limiting the battery cell, and the second lower plastic plate 25 is used for isolating the positive electrode tab of the battery cell from the cover main body 1. The positive pole 2 further comprises a first lower plastic plate 24 and a second lower plastic plate 25, the first lower plastic plate 24 and the second lower plastic plate 25 are arranged on the inner side of the cover plate main body 1, and the first lower plastic plate 24 and the second lower plastic plate 25 are respectively positioned on two sides of the first inner connecting portion 22.

When the cover plate main body 1 seals the box body of the battery module, the first lower plastic plate 24 positioned at the inner side of the cover plate main body 1 is opposite to the position where the battery cell in the box body is positioned, so that the first lower plastic plate 24 limits the battery cell in the box body, and the battery cell is prevented from moving in the battery module after the battery module is installed, and the service performance of the battery is influenced; when the cover plate main body 1 seals the box body of the battery module, the second lower plastic plate 25 positioned at the inner side of the cover plate main body 1 is opposite to the position of the positive electrode lug of the battery core in the box body, so that the second lower plastic plate 25 isolates the positive electrode lug of the battery core from the cover plate main body 1, and the positive electrode lug of the battery core is prevented from being in contact with the cover plate main body 1 to form a short circuit, thereby influencing the service performance of the battery.

In this embodiment, the negative electrode post 3 includes a second outer connection portion 31 and a second inner connection portion 32, the second outer connection portion 31 is connected to an external circuit, and the second inner connection portion 32 is connected to a negative electrode tab of the battery cell. The negative electrode column 3 provided on the cover plate body 1 includes a second outer connecting portion 31 and a second inner connecting portion 32, one end of the second outer connecting portion 31 is located in the cover plate body 1, the other end extends out of the cover plate body 1, one end of the second inner connecting portion 32 is located in the cover plate body 1, and the other end extends into the inner side of the cover plate body 1. The second outer connecting part 31 is located at one end in the cover plate main body 1 and is connected with one end of the second inner connecting part 32 located in the cover plate main body 1, one end of the second outer connecting part 31 extending out of the cover plate main body 1 is connected with an external circuit, and one end of the second inner connecting part 32 extending into the inner side of the cover plate main body 1 is electrically connected with the negative electrode lug of the battery cell.

Copper is very suitable as a negative electrode material because copper has good conductivity, redox and processability, and copper foil is generally used as a negative electrode tab material of a battery cell in the production process of the battery. Therefore, in the present application, the second inner connection portion 32 may be made of copper material, so that the second inner connection portion 32 has better conductivity when electrically connected to the negative electrode tab of the battery cell. The second external connection part 31 may be made of an aluminum material so that the second external connection part 31 has good conductivity when electrically connected to an external circuit, thereby ensuring the performance of the battery.

In this embodiment, the negative electrode post 3 further includes a second sealing ring 33 disposed between the cover main body 1 and the second outer connecting portion 31, and the second sealing ring 33 isolates the second outer connecting portion 31 and the second inner connecting portion 32 from the cover main body 1. The anode stem 3 further includes a second seal ring 33, and the second seal ring 33 is provided at the outer periphery of the second outer connection portion 31 and the second inner connection portion 32 to isolate the second outer connection portion 31 and the second inner connection portion 32 from the cap body 1.

It is envisioned that: the cover main body 1 is further provided with another through hole, one end of the second outer connecting portion 31 is located in the through hole, the other end extends out of the through hole outside the cover main body 1, one end of the second inner connecting portion 32 is located in the through hole, and the other end extends out of the through hole inside the cover. The second sealing ring 33 is provided for sealing the second outer connection part 31 and the second inner connection part 32 on one hand, preventing a gap between the second outer connection part 31 and the second inner connection part 32 and the inner wall of the through hole, thereby providing better sealability of the battery; on the other hand, an insulating region is formed between the second outer connection part 31 and the second inner connection part 32 and the cap body 1, thereby providing a better insulating effect of the battery.

In this embodiment, the negative electrode post 3 further includes a third lower plastic plate 34 and a fourth lower plastic plate 35 disposed on the inner side of the cover main body 1, the third lower plastic plate 34 and the fourth lower plastic plate 35 are disposed on two sides of the second inner connecting portion 32, the third lower plastic plate 34 is used for limiting the battery cell, and the fourth lower plastic plate 35 is used for isolating the negative electrode tab of the battery cell from the cover main body 1. The negative electrode column 3 further comprises a third lower plastic plate 34 and a fourth lower plastic plate 35, the third lower plastic plate 34 and the fourth lower plastic plate 35 are arranged on the inner side of the cover plate main body 1, and the third lower plastic plate 34 and the fourth lower plastic plate 35 are respectively positioned on two sides of the second inner connecting part 32.

When the cover plate main body 1 seals the box body of the battery module, the third lower plastic plate 34 positioned at the inner side of the cover plate main body 1 is opposite to the position where the battery cell in the box body is positioned, so that the third lower plastic plate 34 limits the battery cell in the box body, and the battery cell is prevented from moving in the battery module after the battery module is installed, and the service performance of the battery is influenced; when the cover plate main body 1 seals the box of the battery module, the fourth lower plastic plate 35 positioned on the inner side of the cover plate main body 1 is opposite to the position of the negative electrode lug of the battery cell in the box, so that the fourth lower plastic plate 35 isolates the negative electrode lug of the battery cell from the cover plate main body 1, and the negative electrode lug of the battery cell is prevented from being in contact with the cover plate main body 1 to form a short circuit, thereby influencing the service performance of the battery.

In the present application, the inner side of the fixing platform 41 is flush with the inner side of the cover main body 1, and the fixing platform 41 and the cover main body 1 are of an integral structure. The fixed platform 41 and the cover plate main body 1 are of an integrated structure, the inner side of the fixed platform 41 is flush with the inner side of the cover plate main body 1, the thickness of the fixed platform 41 is smaller than that of the cover plate main body 1, and a groove is formed between the outer side of the fixed platform 41 and the outer side of the cover plate main body 1.

When the explosion-proof valve 5 is fixed on the outer side of the fixed platform 41, the groove accommodates the explosion-proof valve 5, and finally the explosion-proof valve is adhered on the outer side of the cover plate main body 1 through the explosion-proof valve adhesive film 6 to seal the groove, so that the explosion-proof valve 5 is prevented from forming a bulge on the outer side of the cover plate main body 1 to influence the appearance of the battery when being fixed on the fixed platform 41; on the other hand, the explosion-proof valve 5 can be arranged in the groove formed by the outer side face of the fixed platform 41 and the outer side face of the cover plate main body 1, and the groove is sealed through the explosion-proof valve film 6, so that the explosion-proof valve 5 can be better protected, and the using effect of the battery is ensured.

The fixing platform 41 and the cover plate main body 1 are arranged into an integrated structure, so that the structural strength of the cover plate main body 1 is enhanced, and the stability of the battery structure is ensured; on the other hand, when the explosion-proof valve 5 is fixed on the fixing platform 41, the stability of the connection of the explosion-proof valve 5 and the cover plate main body 1 can be enhanced, and the stability of the battery structure can be further enhanced.

The above description may be implemented alone or in various combinations and these modifications are within the scope of the present utility model.

It is noted that relational terms such as first and second, and the like are 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 may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises an element.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present utility model, and are not limiting. Although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present utility model.

Claims

1. A cover plate structure, characterized in that: comprises a cover plate main body (1), an explosion-proof hole (4) arranged on the cover plate main body (1), and an explosion-proof valve (5) arranged outside the explosion-proof hole (4); the explosion-proof valve is characterized in that a fixed platform (41) is arranged in the explosion-proof hole (4), the explosion-proof valve (5) is fixed on the outer side of the fixed platform (41), and a liquid injection channel (42) for injecting electrolyte is arranged on the fixed platform (41).

2. A cover structure as claimed in claim 1, wherein: the cover plate structure further comprises an explosion-proof valve film (6) fixed on the cover plate main body (1), and the explosion-proof valve film (6) is arranged on the outer side of the explosion-proof valve (5).

3. A cover structure as claimed in claim 1, wherein: the cover plate main body (1) is provided with a positive pole (2) for leading out the positive pole of the battery cell and a negative pole (3) for leading out the negative pole of the battery cell.

4. A cover structure as claimed in claim 3, wherein: the positive pole (2) comprises a first outer connecting portion (21) and a first inner connecting portion (22), wherein the first outer connecting portion (21) is connected with an outer circuit, and the first inner connecting portion (22) is connected with a positive pole lug of the battery cell.

5. A cover structure as claimed in claim 4, wherein: the positive pole (2) further comprises a first sealing ring (23) arranged between the cover plate main body (1) and the first outer connecting portion (21), and the first sealing ring (23) isolates the first outer connecting portion (21) and the first inner connecting portion (22) from the cover plate main body (1).

6. A cover structure as claimed in claim 4, wherein: the positive pole (2) is still including locating mould board (24) and second under moulding board (25) under the inboard of apron main part (1), mould board (24) and second under moulding board (25) and locate respectively first internal connection portion (22) both sides, mould board (24) and be used for spacing the electric core under the first, mould board (25) under the second be used for with the positive pole tab of electric core with apron main part (1) is isolated.

7. A cover structure as claimed in claim 3, wherein: the negative pole post (3) comprises a second outer connecting part (31) and a second inner connecting part (32), wherein the second outer connecting part (31) is connected with an outer circuit, and the second inner connecting part (32) is connected with a negative pole lug of the battery cell.

8. A cover structure as claimed in claim 7, wherein: the negative pole post (3) further comprises a second sealing ring (33) arranged between the cover plate main body (1) and the second outer connecting portion (31), and the second sealing ring (33) isolates the second outer connecting portion (31) and the second inner connecting portion (32) from the cover plate main body (1).

9. A cover structure as claimed in claim 7, wherein: the negative pole post (3) is still including locating mould board (34) and fourth down mould board (35) under the third of apron main part (1) inboard, mould board (34) and fourth down mould board (35) and locate respectively second internal connection portion (32) both sides, mould board (34) and be used for spacing the battery cell under the third, mould board (35) under the fourth be used for with the negative pole tab of battery cell with apron main part (1) is isolated.

10. A cover structure as claimed in claim 1, wherein: the inner side of the fixed platform (41) is flush with the inner side of the cover plate main body (1), and the fixed platform (41) and the cover plate main body (1) are of an integrated structure.