Battery cell cover plate and blade battery cell

Abstract

The utility model relates to the technical field of batteries, in particular to a battery cell cover plate and a blade battery cell, the battery cell cover plate comprises a cover plate body, a lower plastic part and an anti-explosion valve, a liquid injection through hole is formed in the cover plate body, the anti-explosion valve is installed on the cover plate body and located on the outer side of the liquid injection through hole, and the anti-explosion valve can communicate with the inner side of the cover plate body through the liquid injection through hole; the lower plastic part is installed on the inner side of the cover plate body, and an exhaust hole communicated with the liquid injection through hole is formed in the lower plastic part. Therefore, the anti-explosion valve welding hole and the liquid injection hole are combined into a whole, that is, the liquid injection through hole is designed in the same cover plate body, the anti-explosion valve and the sealing nail are designed into a whole, and after secondary liquid injection is completed, the anti-explosion valve is placed in the corresponding liquid injection through hole to be welded and sealed such as laser welding; and the explosion-proof valve can be used as a sealing nail for sealing and preventing liquid leakage, and also can realize explosion-proof and exhaust functions, so that a welding procedure is saved, the scrap probability of the blade battery cell is reduced, and the yield is favorably improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell cover and a blade battery cell. Background Art

[0002] At present, in blade cells, the explosion-proof valve and the injection hole are designed on the two cell cover plates on both sides of the shell, respectively. There are the following problems: (1) The explosion-proof valve assembly and the injection hole sealing process are both completed by welding. Poor welding may occur in these two processes, eventually resulting in the scrapping of the blade cell; (2) The explosion-proof valve is first welded to the cover plate, and then the cover plate and the shell are welded and sealed. During this welding and sealing process, if the welding temperature is too high, the explosion-proof valve will be deformed and fail due to heat influence, posing a safety hazard; (3) During the injection process, the electrolyte on the upper side will pass through the electrode group and flow into the explosion-proof valve on the lower cover plate. The electrolyte often flows out, causing the explosion-proof valve patch to fall off, and the electrolyte contaminates the explosion-proof valve. Utility Model Content

[0003] The purpose of the present application is to provide a battery cell cover and a blade battery cell, which to a certain extent solves the technical problem of the prior art that there is an urgent need to develop a blade battery cell with a reasonable explosion-proof valve and injection hole structure, which can effectively improve the yield rate and has fewer safety hazards.

[0004] The present application provides a battery cell cover, comprising: a cover body, a lower plastic part and an explosion-proof valve; wherein the cover body is formed with a liquid injection through hole, the explosion-proof valve is installed on the cover body and is located on the outside of the liquid injection through hole, and the explosion-proof valve can be connected to the inner side of the cover body via the liquid injection through hole; the lower plastic part is installed on the inner side of the cover body, and the lower plastic part is formed with an exhaust hole connected to the liquid injection through hole.

[0005] In the above technical solution, further, a first step groove connected to the injection hole is formed on the outer side of the cover body, and the first step groove is arranged around the outer circumference of the injection hole, and the explosion-proof valve is installed in the first step groove.

[0006] In any of the above technical solutions, further, a second step groove connected to the first step groove is formed on the outer side of the cover body, and the second step groove is arranged around the outer periphery of the first step groove, and the battery cell cover also includes an explosion-proof valve patch, and the explosion-proof valve patch is bonded to the second step groove.

[0007] In any of the above technical solutions, further, the lower plastic part is formed with a buffer groove which is concave inwardly facing away from the cover plate body, and the exhaust hole is formed on the bottom wall and / or side wall of the buffer groove.

[0008] In any of the above technical solutions, further, a first positioning groove communicating with the buffer groove is formed on one side of the lower plastic part close to the cover plate body, and the first positioning groove is arranged along the outer circumference of the buffer groove;

[0009] A first positioning protrusion is formed on one side of the cover body close to the lower plastic part, and the first positioning protrusion is arranged along the outer circumference of the injection through hole; the first positioning protrusion is inserted into the first positioning groove.

[0010] In any of the above technical solutions, further, an exhaust gap is formed on the outer wall of the buffer tank.

[0011] In any of the above technical solutions, further, a second positioning protrusion is formed on one side of the lower plastic part close to the cover body, a second positioning groove is formed on one side of the cover body close to the lower plastic part, and the second positioning protrusion is inserted into the second positioning groove.

[0012] In any of the above technical solutions, further, the battery cover plate also includes a primary sealing nail, and the primary sealing nail is used to be detachably inserted into the injection hole for sealing after the first injection of the battery is completed, and can be removed from the injection hole before the second injection.

[0013] In any of the above technical solutions, further, the primary sealing pin includes a plug-in portion and a sealing portion connected to each other; wherein the plug-in portion is inserted into the liquid injection through hole, and a side of the sealing portion close to the plug-in portion abuts against the outer side of the cover plate body.

[0014] In any of the above technical solutions, further, the primary sealing nail is made of rubber.

[0015] In any of the above technical solutions, further, the explosion-proof valve is a sealing pin formed with a thinned area.

[0016] In any of the above technical solutions, further, the explosion-proof valve is connected to the cover plate body by welding.

[0017] The present application also provides a blade battery cell, comprising a housing, a pole group, and a battery cell cover plate as described in any of the above technical solutions, wherein the pole group is installed in the housing, and the battery cell cover plate is sealed on the opening end of the housing. Therefore, all the beneficial technical effects of the battery cell cover plate are obtained, which will not be described in detail here.

[0018] Compared with the prior art, the beneficial effects of this application are:

[0019] The present application provides a novel battery cell cover, which combines the explosion-proof valve welding hole and the liquid injection hole into one, that is, the liquid injection through hole in the present application is designed on the same cover body, and the explosion-proof valve and the sealing nail are designed as one. After completing the secondary liquid injection, the explosion-proof valve is placed in the corresponding liquid injection through hole for welding and sealing, such as laser welding. The explosion-proof valve can be used as a sealing nail for sealing to prevent leakage, and can also realize the function of explosion-proof exhaust, thereby saving a welding process, reducing the chance of scrapping of blade batteries, and thus helping to improve the yield rate.

[0020] In addition, the battery cell cover in the present application is first welded to the shell. After the liquid is injected through the injection hole, the explosion-proof valve is installed. Therefore, the welding of the battery cell cover and the shell will not cause any impact on the explosion-proof valve, so that the explosion-proof valve will not fail due to heat, which helps to ensure the normal operation of the explosion-proof valve, thereby improving the safety and reliability of the battery.

[0021] In addition, the explosion-proof valve welding hole and the liquid injection hole are combined into one design on the same cover body. After the secondary liquid injection is completed, the explosion-proof valve is installed. Therefore, the electrolyte will not have any impact on the explosion-proof valve, ensuring the normal operation of the explosion-proof valve, and helping to increase the service life of the explosion-proof valve, thereby increasing the service life of the blade battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 An exploded view of a cell cover provided in an embodiment of the present application;

[0024] Figure 2 A schematic diagram of the structure of a battery cell cover provided in an embodiment of the present application;

[0025] Figure 3 A schematic diagram of the structure of the cover plate body provided in an embodiment of the present application;

[0026] Figure 4 for Figure 3 A schematic diagram of the enlarged structure at A;

[0027] Figure 5 An assembly diagram of the cover plate body and the explosion-proof valve provided in an embodiment of the present application;

[0028] Figure 6 for Figure 5 A schematic diagram of the enlarged structure at B;

[0029] Figure 7 A schematic diagram of the structure of the lower plastic part provided in the embodiment of the present application;

[0030] Figure 8 A cross-sectional view of a cell cover provided in an embodiment of the present application;

[0031] Fig. 9 for Figure 8 A schematic diagram of the enlarged structure at C;

[0032] Fig.10 A schematic diagram of the structure of a one-time sealing pin provided in an embodiment of the present application.

[0033] Reference numerals:

[0034] 1-cover body, 11-liquid injection hole, 12-first step groove, 13-second step groove, 2-lower plastic part, 21-buffer groove, 22-exhaust hole, 23-first positioning groove, 24-exhaust notch, 25-first positioning protrusion, 26-second positioning protrusion, 3-explosion-proof valve, 4-explosion-proof valve patch, 5-primary sealing nail, 51-plug-in part, 52-capping part, 6-positive pole, 7-negative pole, 8-upper plastic part, 9-rivet block, 10-sealing ring. DETAILED DESCRIPTION

[0035] The technical solution of the present application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0036] The components of the embodiments of the present application generally described and shown in the drawings herein may be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed, but merely represents the selected embodiments of the present application.

[0037] Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of this application.

[0038] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0039] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0040] Refer to the following Figures 1 to 10 The battery cell cover and the blade battery cell according to some embodiments of the present application are described.

[0041] Embodiment 1

[0042] See also Figures 1 to 9 As shown, an embodiment of the present application provides a battery cover, comprising: a cover body 1, a lower plastic part 2 and an explosion-proof valve 3; wherein the explosion-proof valve 3 is installed on the cover body 1, and preferably, the explosion-proof valve 3 is connected to the cover body 1 by welding, which will be used as an example for explanation hereinafter. Of course, the connection method of the explosion-proof valve 3 and the cover body 1 is not limited to this, and can also be designed according to actual needs;

[0043] The cover body 1 is formed with a liquid injection through hole 11, and the explosion-proof valve 3 is located on the outside of the liquid injection through hole 11, and the explosion-proof valve 3 can be connected with the inner side of the cover body 1 via the liquid injection through hole 11, and the explosion-proof valve 3 is used for exhausting gas in case of thermal runaway; the lower plastic part 2 is installed on the inner side of the cover body 1, and the lower plastic part 2 is formed with an exhaust hole 22 connected with the liquid injection through hole 11, and the aforementioned liquid injection through hole 11 and the exhaust hole 22 can be used as a channel for circulating electrolyte, and can also be used as an exhaust channel in case of thermal runaway.

[0044] Based on the structure described above, it can be known that the present application provides a new type of battery cell cover, which combines the explosion-proof valve welding hole and the liquid injection hole into one, that is, the liquid injection hole 11 in the present application is designed on the same cover body 1, and the explosion-proof valve 3 and the sealing nail are designed as one. After the secondary liquid injection is completed, the explosion-proof valve 3 is placed in the corresponding liquid injection hole 11 for welding and sealing, such as laser welding. The explosion-proof valve 3 can be used as a sealing nail for sealing to prevent leakage, and can also realize the function of explosion-proof exhaust, thereby saving a welding process, reducing the chance of scrapping of blade batteries, and thus helping to improve the yield rate.

[0045] In addition, the battery cell cover in the present application is first welded to the shell. After the liquid is injected through the injection hole 11, the explosion-proof valve 3 is installed. Therefore, the welding of the battery cell cover and the shell will not cause any impact on the explosion-proof valve 3, so that the explosion-proof valve 3 will not fail due to heat, which helps to ensure the normal operation of the explosion-proof valve 3, thereby improving the safety and reliability of the battery.

[0046] In addition, the explosion-proof valve welding hole and the injection hole are combined into one design on the same cover body 1. After the secondary injection is completed, the explosion-proof valve 3 is installed. Therefore, the electrolyte will not have any impact on the explosion-proof valve 3, ensuring the normal operation of the explosion-proof valve 3, and helping to increase the service life of the explosion-proof valve 3, thereby increasing the service life of the blade battery cell.

[0047] Further, preferably, along the height direction of the cover body 1, the liquid injection through hole 11 and the explosion-proof valve 3 are arranged opposite to each other to improve the exhaust effect.

[0048] It should be noted that the inner side of the cover body 1 refers to the side of the cover body 1 close to the pole group of the battery cell, and the outer side of the cover body 1 refers to the side of the cover body 1 away from the pole group of the battery cell, that is, the side exposed to the shell of the battery cell.

[0049] In this embodiment, preferably, Figures 3 to 6 As shown, a first step groove 12 connected to the liquid injection hole 11 is formed on the outer side of the cover body 1, that is, the liquid injection hole 11 and the first step groove 12 are arranged in sequence along the height direction of the cover body 1 and from the inside to the outside; the first step groove 12 is arranged around the periphery of the liquid injection hole 11, and the explosion-proof valve 3 is installed in the first step groove 12.

[0050] According to the structure described above, a first step groove 12 is designed on the cover body 1, and the explosion-proof valve 3 is installed in the first step groove 12, so that the explosion-proof valve 3 and the cover body 1 are installed more stably and firmly, and then the explosion-proof valve 3 and the cover body 1 can be welded together by welding or other processes.

[0051] In this embodiment, preferably, Figures 3 to 6 As shown, a second step groove 13 connected to the first step groove 12 is formed on the outer side of the cover body 1, that is, along the height direction of the cover body 1 and from the inside to the outside, the injection through hole 11, the first step groove 12 and the second step groove 13 are arranged in sequence;

[0052] The second step groove 13 is arranged around the outer periphery of the first step groove 12, and the battery cover also includes an explosion-proof valve patch 4, and the explosion-proof valve patch 4 is installed and bonded in the second step groove 13. It can be seen that along the height direction of the cover body 1 and from the inside to the outside, the injection hole 11, the explosion-proof valve 3 and the explosion-proof valve patch 4 are arranged in sequence, and the explosion-proof valve patch 4 plays a role in protecting the explosion-proof valve 3.

[0053] According to the structure described above, a second step groove 13 is designed on the cover body 1, and the explosion-proof valve patch 4 is installed in the second step groove 13, and is connected by gluing, so that the explosion-proof valve patch 4 and the cover body 1 are installed more stably and firmly, and are not easy to interfere with other structures.

[0054] Further, preferably, along the height direction of the cover body 1 and from the inside to the outside, the injection hole 11, the first step groove 12 and the second step groove 13 are arranged in sequence, and the center lines of the three coincide, that is, the three are arranged directly opposite. Of course, it is not limited to this, and the three can also be arranged non-directly opposite.

[0055] In this embodiment, preferably, Figure 7 As shown, the lower plastic part 2 is formed with a buffer groove 21 which is concave in the direction away from the cover body 1 , that is, the buffer groove 21 is convex on the side of the plastic away from the cover body 1 ; the bottom wall of the buffer groove 21 is formed with an exhaust hole 22 .

[0056] According to the structure described above, a buffer groove 21 is provided on the lower plastic part 2 to mitigate the impact of the electrolyte, and an exhaust hole 22 is provided on the bottom wall of the buffer groove 21. When the battery cell has thermal runaway, a large amount of gas will be produced. The explosion-proof valve 3 is also designed above the buffer groove 21. The exhaust hole 22 is connected to the liquid injection through hole 11, which plays the role of exhausting gas during thermal runaway, thereby ensuring the safety and reliability of the blade battery cell.

[0057] It should be noted that the exhaust holes 22 are not limited to being designed only on the bottom wall of the buffer groove 21 , but may also be designed only on the side wall of the buffer groove 21 , or may be designed on both the bottom wall and the side wall of the buffer groove 21 , depending on actual needs.

[0058] In this embodiment, preferably, Figure 6 and Figure 7 As shown, a first positioning groove 23 communicating with the buffer groove 21 is formed on one side of the cover body 1, and the first positioning groove 23 is arranged along the outer circumference of the buffer groove 21;

[0059] A first positioning protrusion 25 is formed on one side of the cover body 1 close to the lower plastic part 2 , and the first positioning protrusion 25 is arranged along the outer periphery of the injection hole 11 , that is, the first positioning protrusion 25 is annular; the first positioning protrusion 25 is inserted into the first positioning groove 23 .

[0060] According to the structure described above, the first positioning protrusion 25 is inserted into the first positioning groove 23, thereby playing a role in assembling and positioning the cover body 1 and the lower plastic part 2, improving the assembly accuracy and efficiency, and ensuring that the injection hole 11 corresponds to the exhaust hole 22, thereby improving the injection and exhaust efficiency.

[0061] Further, preferably, the first positioning protrusion 25 is an annular structure, and its outer ring is rectangular and its inner ring is elliptical, and the first positioning groove 23 is adapted to the first positioning protrusion 25. Of course, it is not limited to this and can be designed according to actual needs.

[0062] In this embodiment, preferably, Figure 7 As shown, an exhaust notch 24 is formed on the outer wall of the buffer groove 21 .

[0063] According to the structure described above, it can be seen that, on the basis of the exhaust hole 22, an exhaust notch 24 is added to speed up the exhaust rate, which can effectively suppress thermal runaway.

[0064] Furthermore, preferably, there are multiple exhaust notches 24 , which are sequentially arranged along the outer wall of the buffer groove 21 . Adding multiple exhaust notches 24 further accelerates the exhaust rate.

[0065] In this embodiment, preferably, Figure 7 and Figure 8 As shown, a second positioning protrusion 26 is formed on one side of the lower plastic part 2 close to the cover body 1 , a second positioning groove is formed on one side of the cover body 1 close to the lower plastic part 2 , and the second positioning protrusion 26 is inserted into the second positioning groove.

[0066] According to the structure described above, the second positioning protrusion 26 of the lower plastic part 2 can be inserted into the second positioning groove of the cover body 1 to play the role of assembly positioning and ensure that the injection hole 11 corresponds to the exhaust hole 22, thereby improving the injection and exhaust efficiency.

[0067] Further, preferably, the second positioning protrusion 26 may be a cylindrical structure, and correspondingly, the second positioning groove is a circular groove. Of course, this is not limited to this, and the shapes of the second positioning protrusion 26 and the second positioning groove may be designed according to actual needs.

[0068] In this embodiment, preferably, Fig.10 As shown, the cell cover also includes a primary sealing nail 5, and the primary sealing nail 5 is used to be detachably inserted into the injection hole 11 for sealing after the first injection of the battery is completed, and can be taken out from the injection hole 11 before the second injection.

[0069] According to the structure described above, it can be known that when the cover body 1 integrated with the lower plastic part 2 is welded on the shell, and when a liquid injection is completed through the liquid injection hole 11, the one-time sealing nail 5 designed in the present application can be inserted into the liquid injection hole 11 to play a temporary sealing role, and then the chemical formation is carried out. When the chemical formation is completed, the one-time sealing nail 5 is taken out from the liquid injection hole 11, and then a second liquid injection is carried out. After the liquid injection is completed, the explosion-proof valve 3 is installed in the aforementioned first step groove 12, and can be connected to the cover body 1 by welding, so as to play a role of sealing the liquid injection hole 11. It can be seen that the one-time sealing nail 5 provided in the present application can be reused, saving costs.

[0070] In this embodiment, preferably, Fig.10 As shown, the primary sealing nail 5 includes a plug-in portion 51 and a sealing portion 52 connected to each other; wherein the plug-in portion 51 is detachably inserted into the liquid injection through hole 11, and a side of the sealing portion 52 close to the plug-in portion 51 abuts against the outer side of the cover body 1.

[0071] According to the structure described above, the plug-in portion 51 is plugged into the liquid injection hole 11 to seal the liquid injection hole 11, and the cover portion 52 can be installed in the second step groove 13 of the cover body 1 to further seal the end to avoid leakage.

[0072] Further, preferably, the primary sealing nail 5 is made of rubber, which has a good sealing effect, and preferably, the primary sealing nail 5 can be integrally formed by injection molding.

[0073] In this embodiment, preferably, the explosion-proof valve 3 is a sealing nail formed with a thinned area.

[0074] According to the structure described above, a thinning area such as a cross-shaped structure can be processed on the existing sealing nail, so that when thermal runaway occurs, the thinning area can be broken to perform exhaust and pressure relief, and preferably, the sealing nail is made of aluminum, which has a certain strength and hardness, and can be used as an explosion-proof valve 3. Of course, it is not limited to this, and an ordinary explosion-proof valve 3 in the prior art can also be used.

[0075] In this embodiment, preferably, Fig.10 As shown, the explosion-proof valve 3 can be elliptical, but is not limited thereto. It can also be circular or other shapes, etc., and can be designed according to actual needs.

[0076] In this embodiment, preferably, Figure 1As shown, the cell cover also includes a positive electrode column 6, a negative electrode column 7, an upper plastic part 8, a rivet block 9 and a sealing ring 10; wherein, the positive electrode column 6 and the negative electrode column 7 are equipped with the same upper plastic part 8 and the rivet block 9, the positive electrode column 6 and the negative electrode column 7 are inserted into the plain aluminum sheet and the lower plastic part 2, and are fixed by the rivet block 9, the upper plastic part 8 is to be shot outside the positive electrode column 6 and the negative electrode column 7, and isolated between the rivet block 9, the electrode column and the cover body 1; the positive electrode column 6 and the negative electrode column 7 are both sleeved with a sealing ring 10, and are used to isolate the cover body 1 from the electrode column, playing the role of insulation and sealing.

[0077] Embodiment 2

[0078] The second embodiment of the present application also provides a blade battery cell, comprising a housing, an electrode group, and the battery cell cover plate described in the first embodiment, wherein the electrode group is installed in the housing, and the battery cell cover plate is sealed on the opening end of the housing. Therefore, it has all the beneficial technical effects of the battery cell cover plate, and the same technical features and beneficial effects are not repeated.

[0079] Further, preferably, openings are formed at both ends of the shell along a preset direction, and any opening is provided with the battery cell cover plate of the present application. Of course, it is not limited to this and can also be designed according to actual needs.

[0080] Further, preferably, the preset direction may be the length direction of the shell, but of course, it is not limited thereto.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery cell cover, characterized in that: include: A cover body, a lower plastic part and an explosion-proof valve; wherein the cover body is formed with a liquid injection through hole, the explosion-proof valve is installed on the cover body and is located on the outside of the liquid injection through hole, and the explosion-proof valve can be connected with the cover body via the liquid injection through hole; the lower plastic part is installed on the inner side of the cover body, and the lower plastic part is formed with an exhaust hole connected with the liquid injection through hole.

2. The cell cover plate according to claim 1, characterized in that: A first step groove communicating with the liquid injection through hole is formed on the outer side of the cover plate body, and the first step groove is arranged around the outer circumference of the liquid injection through hole, and the explosion-proof valve is installed in the first step groove.

3. The cell cover plate according to claim 2, characterized in that: A second step groove connected to the first step groove is formed on the outer side of the cover body, and the second step groove is arranged around the outer circumference of the first step groove. The battery cover also includes an explosion-proof valve patch, and the explosion-proof valve patch is bonded into the second step groove.

4. The cell cover plate according to claim 1, characterized in that: The lower plastic part is formed with a buffer groove which is concave inwardly facing away from the cover plate body, and the bottom wall and / or side wall of the buffer groove is formed with the exhaust hole.

5. The cell cover plate according to claim 4, characterized in that: A first positioning groove connected to the buffer groove is formed on one side of the lower plastic part close to the cover body, and the first positioning groove is arranged along the outer periphery of the buffer groove; a first positioning protrusion is formed on one side of the cover body close to the lower plastic part, and the first positioning protrusion is arranged along the outer periphery of the injection through hole; the first positioning protrusion is inserted into the first positioning groove; and / or An exhaust notch is formed on the outer wall of the buffer tank.

6. The cell cover plate according to claim 1, characterized in that: A second positioning protrusion is formed on one side of the lower plastic part close to the cover body, a second positioning groove is formed on one side of the cover body close to the lower plastic part, and the second positioning protrusion is inserted into the second positioning groove.

7. The cell cover plate according to claim 1, characterized in that: The cell cover plate further comprises a primary sealing nail, and the primary sealing nail is used to be detachably inserted into the injection through hole for sealing after the primary injection of the battery is completed, and can be taken out from the injection through hole before the secondary injection.

8. The cell cover plate according to claim 7, characterized in that: The primary sealing nail comprises a plug-in portion and a cover portion connected to each other; wherein the plug-in portion is inserted into the liquid injection through hole, and a side of the cover portion close to the plug-in portion abuts against the outer side of the cover plate body; and / or The material of the primary sealing nail is rubber.

9. The cell cover plate according to any one of claims 1 to 8, characterized in that: The explosion-proof valve is a sealing nail formed with a thinned area; and / or The explosion-proof valve is connected to the cover plate body by welding.

10. A blade battery cell, characterized in that: It comprises a shell, a pole group and a cell cover plate as claimed in any one of claims 1 to 9; wherein the pole group is installed in the shell, and the cell cover plate is sealed on the open end of the shell.

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