Battery cell

Abstract

The utility model relates to the technical field of batteries, in particular to a battery cell which comprises a shell, a pole group, a supporting flat base plate and a cover plate assembly, the pole group is mounted in the shell, and the cover plate assembly covers the open end of the shell; the pole group forms tabs, the supporting flat base plate is mounted at one end, where the tabs are formed, of the pole group, and at least part of the tabs penetrate through the supporting flat base plate and extend to the cover plate assembly side; the cover plate assembly comprises a cover plate body, an insulating sheet, a lower plastic part and a pole post, the pole post is mounted on the inner side of the cover plate body and connected with the tab of the pole group, and one end part of the pole post penetrates through the cover plate body and extends to the outer side of the cover plate body; the lower plastic part is mounted between the pole and the inner side of the cover plate body, and insulating sheets are arranged on the inner side surfaces of the cover plate body on the two sides of the lower plastic part. The supporting flat base plate is arranged for the pole group, it is guaranteed that all the positions of the pole group are evenly stressed, the pole group is prevented from being damaged, shell entering is convenient, the lower plastic part is replaced with the insulating sheet, space is saved, and the problem that the lower plastic part is prone to deformation is solved.

Description

Technical Field

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

[0002] At present, lithium batteries include a shell, an electrode group and a cover assembly, wherein the electrode group is installed in the shell, and a cover assembly is provided at least at one end of the shell along a preset direction, and the cover assembly generally includes a bare aluminum plate and a lower plastic structure, wherein the lower plastic is installed on the lower surface of the bare aluminum plate and extends over the entire length of the bare aluminum plate, that is, on the side close to the electrode group. The end of the electrode group close to the cover assembly is uneven, and the lower plastic generally has two ends protruding toward the electrode group side. In the case of shaking during assembly or later use, the electrode group is subjected to extremely uneven force, which may cause damage to the electrode sheet of the electrode group. Moreover, when the electrode group is put into the shell, force is directly applied to the end of the electrode group, which is not only inconvenient to operate, but also very easy to cause damage to the electrode group. In addition, the height of the lower plastic is generally around 5mm, which occupies the space of the pole group, reduces the space utilization, reduces the battery cell capacity, and has a high material cost. Moreover, the lower plastic is generally softer and easy to shrink and deform. There is a risk of deformation when the cover plate is matched and the pole ear is welded. If the lower plastic and the bare aluminum plate are not matched evenly, there is a risk of the pole ear being stuck in the gap. Utility Model Content

[0003] The purpose of the present application is to provide a battery cell, which to a certain extent solves the technical problems in the prior art that a new type of lithium battery cell is urgently needed to be developed, so that its electrode group is evenly stressed in the shell, not easily damaged, and easy to enter the shell, and the cover part occupies little space and is not easily deformed.

[0004] The present application provides a battery cell, comprising: a shell, a pole group, a support plate and a cover plate assembly; wherein the pole group is installed in the shell, and the cover plate assembly is sealed on the open end of the shell; the pole group is formed with a pole ear, the support plate is installed on one end of the pole group where the pole ear is formed, the support plate is formed with an opening, and at least part of the pole ear of the pole group passes through the support plate and extends to a side close to the cover plate assembly;

[0005] The cover assembly includes a cover body, an insulating sheet, a lower plastic part and a pole, wherein the pole is installed on the inner side of the cover body and is connected to the pole ear of the pole group, and one end of the pole extends through the cover body to the outer side of the cover body; the lower plastic part is installed between the pole and the inner side of the cover body, and the insulating sheet is provided on the inner surface of the cover body on both sides of the lower plastic part.

[0006] In the above technical solution, further, the opening extends along the length direction of the supporting flat pad.

[0007] In any of the above technical solutions, further, the support flat pad is heat-fused together with the Mylar film wrapped around the electrode group, or the support flat pad is glued together with the Mylar film wrapped around the electrode group.

[0008] In any of the above technical solutions, further, the material of the supporting flat pad is plastic or rubber.

[0009] In any of the above technical solutions, further, the pole column and the pole lug of the pole group are connected by welding.

[0010] In any of the above technical solutions, further, the insulating sheet is connected to the cover body by gluing.

[0011] In any of the above technical solutions, further, the lower plastic part is adapted to the pole.

[0012] In any of the above technical solutions, further, the battery cell also includes an explosion-proof valve, and the explosion-proof valve is provided on the long narrow side of the shell formed by its long side and wide side, and the explosion-proof valve is connected to the interior of the shell.

[0013] In any of the above technical solutions, further, the battery cell also includes a side plate, and the side plates are arranged on both sides of the electrode group along a preset direction, and when the side plates are arranged close to the explosion-proof valve side, the side plates are formed with exhaust holes.

[0014] In any of the above technical solutions, further, the pole includes an insertion portion and a connecting portion that are connected to each other; wherein the insertion portion is arranged on a side of the connecting portion close to the cover body; the insertion portion is sequentially passed through the lower plastic part and the cover body; the side of the connecting portion that is away from the cover body is used to abut against the pole ear of the pole group, and is connected by welding.

[0015] In any of the above technical solutions, further, the lower plastic part is provided with a first installation groove, the connecting part is installed in the first installation groove, and one end of the insertion part sequentially passes through the lower plastic part and the cover body and extends to the outside of the cover body.

[0016] In any of the above technical solutions, further, the cover assembly also includes a convex-shaped sealing ring, and the sealing ring is sleeved on the outside of the plug-in part and abuts against a side surface of the connecting part close to the cover body; the sealing ring is pressed between the cover body, the plug-in part and the connecting part.

[0017] In any of the above technical solutions, further, the cover plate assembly also includes an upper plastic part and a pressing component; wherein the pressing component is sleeved on one end of the pole exposed on the cover plate body, and at least part of the structure of the upper plastic part is pressed between the pressing component and the cover plate body.

[0018] In any of the above technical solutions, further, the upper plastic part is provided with a second installation groove, and the pressing member is arranged in the second installation groove.

[0019] In any of the above technical solutions, further, the pressing member is connected to the pole by riveting or welding.

[0020] In any of the above technical solutions, further, the pressing member and the upper plastic part are integrally injection molded by encapsulation.

[0021] In any of the above technical solutions, further, one of the upper plastic part and the pressing member is formed with a positioning protrusion, the other of the upper plastic part and the pressing member is formed with a positioning groove, and the positioning protrusion is arranged in the positioning groove.

[0022] Compared with the prior art, the beneficial effects of this application are:

[0023] In the battery cell provided in the present application, a supporting flat pad is provided at one end of the electrode group where the electrode ear is formed, and the end face of the supporting flat pad that cooperates with the cover plate assembly is flat, thereby increasing the supporting area, thereby effectively avoiding deformation and damage caused by uneven local force on the electrode group. In addition, when the electrode group is put into the shell, force can be applied to the supporting flat pad to increase the shell entry rate, thereby helping to improve production efficiency, and force is not directly applied to the electrode group, which plays a role in protecting the electrode group, avoiding damage to the electrode group, and thereby avoiding problems such as short circuits in the later stage, thereby improving the safety and reliability of the battery cell.

[0024] In addition, the present application eliminates the structure of all lower plastic parts except the pole position, and only sets a thinner insulating sheet on the cover body. The structure is simple and the molding process is mature. Compared with the lower plastic parts with a certain thickness and throughout the entire length of the cover body in the prior art, the material cost is low and the space occupied by the pole group is reduced. For example, the height space can be saved by about 3-4mm, which greatly improves the space utilization rate and increases the capacity of the battery cell. Moreover, the insulating sheet is tightly attached to the cover body, with the cover body as the basis, and the whole is not easy to deform, so there will be no situation where the pole ear is stuck in the gap. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] 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.

[0026] Figure 1 An exploded diagram of a battery cell provided in an embodiment of the present application;

[0027] Figure 2 A schematic diagram of the structure of the support flat pad provided in the embodiment of the present application;

[0028] Figure 3 A schematic diagram of the structure of a battery cell provided in an embodiment of the present application;

[0029] Figure 4 for Figure 3 Partial cross-sectional view along section AA;

[0030] Figure 5 Another schematic diagram of the structure of the battery cell provided in the embodiment of the present application;

[0031] Figure 6 for Figure 5 A partial cross-sectional view along section BB;

[0032] Figure 7 An exploded view of a cover plate assembly provided in an embodiment of the present application;

[0033] Figure 8 An assembly diagram of the cover plate assembly provided in an embodiment of the present application.

[0034] Reference numerals:

[0035] 1-shell, 2-pole group, 21-pole ear, 3-support flat pad, 31-opening, 4-cover assembly, 41-cover body, 411-installation through hole, 42-insulating sheet, 43-lower plastic part, 431-avoidance through hole, 44-pole, 441-insertion part, 442-connecting part, 45-sealing ring, 46-upper plastic part, 47-pressed component, 5-Mylar film, 6-side plate, 7-explosion-proof valve. DETAILED DESCRIPTION

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] Refer to the following Figures 1 to 8 The battery cell according to some embodiments of the present application is described.

[0042] See also Figures 1 to 8 As shown, an embodiment of the present application provides a battery cell, comprising: a shell 1, a pole group 2, a support plate 3 and a cover assembly 4; wherein the pole group 2 is installed in the shell 1, and the cover assembly 4 is sealed at the opening 31 end of the shell 1; the pole group 2 is formed with a pole ear 21, the support plate 3 is installed at one end of the pole group 2 where the pole ear 21 is formed, the support plate 3 is formed with an opening 31, and at least part of the pole ear 21 of the pole group 2 passes through the support plate 3 and extends to a side close to the cover assembly 4;

[0043] The cover assembly 4 includes a cover body 41, an insulating sheet 42, a lower plastic part 43 and a pole 44. The pole 44 is installed on the inner side of the cover body 41, and the pole 44 is connected to the pole ear 21 of the pole group 2. One end of the pole 44 passes through the cover body 41 and extends to the outer side of the cover body 41. In other words, the cover body 41 is formed with a mounting through hole 411 that runs through the inner and outer sides thereof, and one end of the pole 44 can extend to the outer side of the cover body 41 through the mounting through hole 411. Here, it should be noted that the inner side mentioned above refers to the side close to the pole group. 2, that is, the side located inside the shell 1, and the above-mentioned outside refers to the side away from the pole group 2, that is, the side exposed outside the shell 1; the lower plastic part 43 is installed between the pole 44 and the inner side of the cover body 41. It can be seen that the lower plastic part 43 is provided with an avoidance through hole 431, and one end of the pole 44, that is, the insertion part 441 described below, sequentially passes through this avoidance through hole 431 and the aforementioned installation through hole 411 to extend to the outside of the cover body 41; wherein the inner surface of the cover body 41 located on both sides of the lower plastic part 43 is provided with an insulating sheet 42.

[0044] Based on the structure described above, it can be known that in the battery cell provided by the present application, a supporting flat pad 3 is provided at one end of the electrode group 2 where the electrode ear 21 is formed, and the end surface of the supporting flat pad 3 cooperating with the cover plate assembly 4 is a plane, which increases the supporting area, thereby effectively avoiding local uneven force on the electrode group 2, resulting in deformation and damage, etc. In addition, when the electrode group 2 is put into the shell, force can be applied to the supporting flat pad 3 to increase the shell entry rate, thereby helping to improve production efficiency, and without directly applying force to the electrode group 2, it plays a role in protecting the electrode group 2, avoiding damage to the electrode group 2, and thus avoiding problems such as short circuits in the later stage, thereby improving the safety and reliability of the battery cell.

[0045] In addition, in the present application, the structure of all lower plastic parts except the position of the pole 44 is eliminated, and only a thinner insulating sheet 42 is set on the cover body 41. The structure is simple and the molding process is mature. Compared with the lower plastic part 43 with a certain thickness and covering the entire length of the cover body 41 in the prior art, the material cost is low and the space occupied by the pole group 2 is reduced. For example, the height space can be saved by about 3-4mm, which greatly improves the space utilization rate and the capacity of the battery cell. Moreover, the insulating sheet 42 is tightly attached to the cover body 41, with the cover body 41 as the basis, and the whole is not easy to deform, so the pole ear 21 will not be stuck in the gap.

[0046] In this embodiment, preferably, Figure 1 and Figure 2 As shown, the opening 31 extends along the length direction of the support flat pad 3, which can lead out more pole lugs 21, increase the contact area between the pole lugs 21 and the pole 44, and increase the current capacity. Of course, it is not limited to this, and can also be designed according to actual needs.

[0047] In this embodiment, preferably, Figure 1 As shown, the support flat pad 3 and the Mylar film 5 wrapped around the electrode group 2 are heat-fused together. The process is mature and the operation is simple. The support flat pad 3 and the electrode group 2 are assembled together directly by melting the Mylar film 5.

[0048] It should be noted that the connection method between the support plate 3 and the Mylar film 5 wrapped around the electrode group 2 is not limited to hot melting, and other methods may be used, such as gluing the support plate 3 and the Mylar film 5 wrapped around the electrode group 2 together.

[0049] In this embodiment, preferably, the material of the support plate 3 is plastic or rubber, which has certain strength and hardness, and has insulation properties to avoid short circuit. Of course, the material of the support plate 3 is not limited to the above, and other insulating materials can be selected according to actual needs.

[0050] In this embodiment, preferably, the pole 44 is connected to the pole lug 21 of the pole group 2 by welding, which has a mature process and makes the connection between the two more stable and firm.

[0051] In this embodiment, preferably, Figure 1 As shown, the battery cell further includes an explosion-proof valve 7 , and the explosion-proof valve 7 is provided on the long narrow side of the housing 1 formed by its long sides and wide sides, and the explosion-proof valve 7 is connected to the interior of the housing 1 .

[0052] According to the structure described above, it can be seen that the explosion-proof valve 7 is provided on the side of the shell 1, which shortens the exhaust path, helps to quickly exhaust the gas, and can effectively suppress thermal runaway.

[0053] Further, preferably, the number of explosion-proof valves 7 can be multiple, and they are sequentially spaced along the length direction of the shell 1. Of course, it is not limited to this, and the number of explosion-proof valves 7 can be one.

[0054] Further, preferably, the housing 1 has two oppositely disposed long narrow sides, and an explosion-proof valve 7 may be provided on one of the long narrow sides, or on both of the long narrow sides, depending on actual needs.

[0055] Further, preferably, the shell 1 is in a rectangular parallelepiped shape, and its length is greater than the width and height, especially much greater than the width, so that the shell 1 is in a blade shape. Of course, it is not limited to this and can be designed according to actual needs.

[0056] In this embodiment, preferably, Figure 1 As shown, the battery cell further includes a side plate 6, and the side plates 6 are provided on both sides of the electrode group 2 along a preset direction, such as its height direction. Of course, this preset direction is not limited to this, and can also be selected according to actual needs;

[0057] When the side plate 6 is disposed close to the explosion-proof valve 7, an exhaust through hole is formed on the side plate 6 for exhausting the gas.

[0058] According to the structure described above, side plates 6 are provided on both sides of the preset direction of the electrode group 2 to facilitate the entry into the shell and protect the electrode group 2. Of course, the invention is not limited to this, and the structure of the side plates 6 may not be designed, and the design is specifically based on actual needs.

[0059] Further, preferably, the side plate 6 and the Mylar film 5 wrapped around the electrode group 2 can be connected by hot melting or gluing.

[0060] In this embodiment, preferably, Figure 4 , Figure 6 , Figure 7 and Figure 8 As shown, the pole 44 includes an insertion portion 441 and a connecting portion 442 connected to each other; wherein the insertion portion 441 is arranged on a side of the connecting portion 442 close to the cover body 41; the insertion portion 441 is sequentially penetrated through the lower plastic part 43 and the cover body 41; the side of the connecting portion 442 facing away from the cover body 41 is used to abut against the pole ear 21 of the pole group 2, and is connected by welding.

[0061] According to the structure described above, it can be known that the insertion portion 441 extends through the cover body 41 to the outside, serving as the main output; the connecting portion 442 serves as a connection structure with the pole ear 21 of the pole group 2, which increases the welding area and helps to improve the firmness and stability of the welding structure, and the connecting portion 442 also serves to limit the insertion portion 441.

[0062] Further, preferably, the connecting portion 442 and the inserting portion 441 may be an integrated structure. Of course, the present invention is not limited thereto. The connecting portion 442 and the inserting portion 441 may also be connected by welding or the like.

[0063] Further, preferably, the connection part 442 is a flat plate structure with a small thickness and occupies a small space. Of course, it is not limited to this. The connection part 442 can also be a block or other structure, which can be selected according to actual needs.

[0064] It should be noted here that the aforementioned pole lug 21 refers to a flattened pole lug cluster, which is arranged along the inner side surface parallel to the cover body 41 .

[0065] In this embodiment, preferably, Figure 8 As shown, the lower plastic part 43 is provided with a first installation groove, the connecting part 442 is installed in the first installation groove, and one end of the inserting part 441 passes through the lower plastic part 43 and the cover body 41 in sequence and extends to the outside of the cover body 41.

[0066] According to the structure described above, the connecting portion 442 is installed in the first installation groove, so that the pole 44 and the lower plastic part 43 are assembled more stably and firmly. In addition, the lower plastic part 43 can cover the side of the connecting portion 442 to play an insulating protection role, which is safer and more reliable.

[0067] Further, preferably, the first mounting groove of the lower plastic part 43 is matched with the connecting portion 442, that is, the lower plastic part 43 is matched with the pole 44, and the area occupied by the lower plastic part 43 is small, only the pole 44 is needed, and the insulating sheet 42 can be used in other positions.

[0068] Of course, the structure of the lower plastic part 43 is not limited to the above, and the lower plastic part 43 may also be a flat plate structure, etc. The lower plastic part 43 will not wrap the side of the connecting part 442, and the specific selection is based on actual needs.

[0069] In this embodiment, preferably, Figure 4 , Figure 6 and Figure 7 As shown, the cover assembly 4 also includes a convex-shaped sealing ring 45, and the sealing ring 45 is sleeved on the outside of the insertion portion 441 and abuts against a side surface of the connecting portion 442 close to the cover body 41; the sealing ring 45 is pressed between the cover body 41 and the insertion portion 441 and the connecting portion 442.

[0070] According to the structure described above, a portion of the sealing ring 45 extends into the mounting through hole 411 of the cover body 41, and is blocked between the inner wall of the mounting through hole 411 and the outer wall of the insertion portion 441, playing a role of insulation protection and sealing. Another portion of the sealing ring 45 is located in the avoidance through hole 431, and this partial structure blocks the inner surface of the cover body 41 and the connecting portion 442 together, playing a role of insulation protection and sealing.

[0071] In this embodiment, preferably, Figure 4 , Figure 6 and Figure 7 As shown, the cover assembly 4 also includes an upper plastic part 46 and a pressing component 47; wherein the pressing component 47 is sleeved on one end of the pole 44 exposed to the cover body 41, and at least part of the structure of the upper plastic part 46 is pressed between the pressing component 47 and the cover body 41.

[0072] According to the structure described above, the pole 44, the lower plastic part 43 and the cover body 41 are fixed together by the pressing component 47, and the overall structure is stronger and more stable. The upper plastic part 46 plays the role of insulating and protecting the pressing component 47 and the cover body 41 to avoid problems such as short circuits.

[0073] Further, preferably, both the upper plastic part 46 and the pressing member 47 are provided with through holes penetrating through both sides thereof along the thickness direction thereof, so as to play the role of avoiding the pole 44 .

[0074] In this embodiment, preferably, Figure 4 , Figure 6 and Figure 7 As shown, the upper plastic part 46 is provided with a second installation groove, and the pressing component 47 is disposed in the second installation groove.

[0075] According to the structure described above, it can be known that the pressing component 47 is installed in the second installation groove, so that the upper plastic part 46 can wrap the periphery of the pressing component 47, further improving the insulation performance.

[0076] In this embodiment, preferably, Figure 4 , Figure 6 and Figure 7 As shown, the pressing member 47 is connected to the pole 44 by riveting, which is simpler and more convenient to operate, and makes the connection between the pole 44 and the pressing member 47 more firmly and more stably. Of course, the connection method between the pressing member 47 and the pole 44 is not limited to the above, and other connection methods can also be used, such as welding.

[0077] In this embodiment, preferably, Figure 4 , Figure 6 and Figure 7 As shown, the pressed component 47 and the upper plastic part 46 are integrally injection molded by encapsulation. The encapsulation process is relatively mature, the structural strength after molding is relatively high, a platform design can be achieved, and the development cost of the cover plate structure can be reduced.

[0078] In this embodiment, preferably, one of the upper plastic part 46 and the pressing member 47 is formed with a positioning protrusion, and the other of the upper plastic part 46 and the pressing member 47 is formed with a positioning groove, and the positioning protrusion is arranged in the positioning groove (not shown in the figure).

[0079] According to the structure described above, it can be known that through the cooperation of the positioning protrusion and the positioning groove, an interlocking connection between the two is achieved, making the connection between the two more stable and firm.

[0080] Further, preferably, the relative two side portions of the pressing member 47 are provided with the aforementioned positioning protrusions, and correspondingly, the relative two inner walls of the upper plastic part 46 are provided with positioning grooves, and the positioning protrusions and the positioning grooves correspond one to one. Of course, this is not limited to this, and the layout of the positioning protrusions and the positioning grooves is not limited to the above, and can also be selected according to actual needs.

[0081] It should also be noted here that: it is not limited to providing a positioning protrusion on the inner wall of the upper plastic part 46 and providing a positioning groove on the outer wall of the press-fitted component, and the following structure can also be adopted: for example: the outer wall of the press-fitted component is provided with a positioning protrusion, the inner wall of the upper plastic part 46 is provided with a positioning groove, and the positioning protrusion is provided in the positioning groove.

[0082] In this embodiment, preferably, Figure 4 As shown, the insulating sheet 42 is connected to the cover body 41 by gluing, that is, the insulating sheet 42 is adhered to the inner surface of the cover body 41, which is simple and convenient to operate and has high production efficiency.

[0083] In this embodiment, preferably, the material of the insulating sheet 42 can be one of thermoplastic polyesters such as polyethylene terephthalate (PET), high-performance fluoroplastics such as polyperfluoroalkoxy (PFA) and polycarbonate plastic (PC). Of course, it is not limited to this, and the material of the insulating sheet 42 can also be selected according to actual needs.

[0084] 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, characterized in that: include: A shell, a pole group, a support plate and a cover plate assembly; wherein the pole group is installed in the shell, and the cover plate assembly is sealed on the open end of the shell; the pole group is formed with a pole ear, the support plate is installed on one end of the pole group where the pole ear is formed, the support plate is formed with an opening, and at least part of the pole ear of the pole group passes through the support plate and extends to a side close to the cover plate assembly; The cover assembly includes a cover body, an insulating sheet, a lower plastic part and a pole, wherein the pole is installed on the inner side of the cover body and is connected to the pole ear of the pole group, and one end of the pole extends through the cover body to the outer side of the cover body; the lower plastic part is installed between the pole and the inner side of the cover body, and the insulating sheet is provided on the inner surface of the cover body on both sides of the lower plastic part.

2. The battery cell according to claim 1, characterized in that: The opening extends along the length direction of the supporting flat pad.

3. The battery cell according to claim 1, characterized in that: The support flat pad is heat-fused together with the Mylar film wrapped outside the electrode group, or the support flat pad is glued together with the Mylar film wrapped outside the electrode group.

4. The battery cell according to claim 1, characterized in that: The material of the supporting flat pad is plastic or rubber; and / or The pole column is connected to the pole lug of the pole group by welding; and / or The insulating sheet is connected to the cover plate body by gluing; and / or The lower plastic part is matched with the pole.

5. The battery cell according to claim 1, characterized in that: The battery core further includes an explosion-proof valve, and the explosion-proof valve is disposed on the long narrow side of the shell formed by the long side and the wide side thereof.

6. The battery cell according to claim 5, characterized in that: The battery cell further includes side plates, which are disposed on both sides of the electrode group along a preset direction, and when the side plates are disposed close to the explosion-proof valve, exhaust holes are formed on the side plates.

7. The battery cell according to claim 1, characterized in that: The pole includes an insertion portion and a connecting portion connected to each other; wherein the insertion portion is arranged on a side of the connecting portion close to the cover body; the insertion portion is sequentially penetrated through the lower plastic part and the cover body; the side of the connecting portion away from the cover body is used to abut against the pole ear of the pole group and is connected by welding.

8. The battery cell according to claim 7, characterized in that: The lower plastic part is provided with a first mounting groove, the connecting part is mounted in the first mounting groove, and one end of the insertion part sequentially passes through the lower plastic part and the cover body and extends to the outside of the cover body; and / or The cover assembly also includes a convex-shaped sealing ring, which is sleeved on the outside of the insertion part and abuts against a side surface of the connecting part close to the cover body; the sealing ring is pressed between the cover body, the insertion part and the connecting part.

9. The battery cell according to any one of claims 1 to 8, characterized in that: The cover assembly further comprises an upper plastic part and a pressing member, wherein the pressing member is sleeved on one end of the pole exposed from the cover body, and at least part of the structure of the upper plastic part is pressed between the pressing member and the cover body.

10. The battery cell according to claim 9, characterized in that: The upper plastic part is provided with a second mounting groove, and the pressing member is arranged in the second mounting groove; and / or The pressing member is connected to the pole by riveting or welding; and / or The pressing member and the upper plastic part are integrally injection molded by encapsulation; and / or One of the upper plastic part and the pressing member is formed with a positioning protrusion, the other of the upper plastic part and the pressing member is formed with a positioning groove, and the positioning protrusion is arranged in the positioning groove.

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