Cover plate assembly, battery cell and battery pack

Abstract

The utility model relates to the technical field of batteries, and discloses a cover plate assembly, a battery cell and a battery pack, the cover plate assembly comprises a cover plate body, a first insulating part, a second insulating part, a pole post and a connecting sheet, when the cover plate assembly is used, the cover plate assembly is arranged on the opening of the battery cell shell, and the anti-rotation part on the cover plate body is matched with the matching part on the second conductive part, so that the pole is prevented from rotating relative to the cover plate body when being stressed, and the stability of the cover plate assembly and the battery cell can be effectively ensured. Meanwhile, the bending process of the connecting piece is omitted in the manufacturing process of the battery cell, the tab is attached to the outer wall surface of the second connecting part after being bent, and the connecting piece and the cover plate assembly horizontally extend in parallel, so that the space occupied by the bending of the connecting piece and the bending of the tab in the height direction of the battery cell can be effectively reduced; and the space in the shell can be fully utilized to arrange the pole group with larger capacity, so that the space utilization rate in the battery cell and the volume energy density of the battery cell are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and particularly relates to a cover plate assembly, an electric core and a battery pack. Background Art

[0002] The electric core includes a housing, a cover plate assembly and a pole group. The connecting piece inside the housing and the pole ear extend towards each other for a certain distance and then are respectively bent to form a connecting piece bent end and a pole ear bent end. After the connecting piece bent end and the pole ear bent end are welded, the electrical connection between the pole ear and the connecting piece is formed. For the electric core with such a structure, since the bending of the connecting piece and the bending of the pole ear occupy a certain space in the height of the electric core, the space utilization rate inside the electric core is low. The cover plate assembly includes a cover plate body, a first insulating member, a sealing member and a second insulating member. The cover plate body is provided with a pole post hole, and the pole post is arranged in the pole post hole. For a cylindrical pole post, after the pole post is matched with the pole post hole, the pole post is prone to rotate relative to the cover plate body when stressed, affecting the stability of the overall structure of the electric core. Content of the Utility Model

[0003] In view of this, the utility model provides a cover plate assembly, an electric core and a battery pack to solve the problems of low space utilization rate and poor stability of the electric core in the prior art.

[0004] In the first aspect, the utility model provides a cover plate assembly, including:

[0005] A cover plate body, on which two pole post mounting holes and an operation hole are provided; and an anti-rotation part is provided on the cover plate body;

[0006] A first insulating member, arranged on the outer wall surface of the cover plate body;

[0007] A second insulating member, arranged on the inner wall surface of the cover plate body;

[0008] A pole post, arranged in the pole post mounting hole, the pole post includes a first conductive part and a second conductive part, the first end of the first conductive part extends into the pole post mounting hole, and the second end of the first conductive part is pressed on the first insulating member; the second conductive part is connected to the first end of the first conductive part, and a matching part is provided on the second conductive part, and the matching part cooperates with the anti-rotation part to prevent the pole post from rotating relative to the cover plate body;

[0009] The connecting piece is disposed inside the cover plate body in parallel with the cover plate body. The connecting piece includes a first connecting portion and a second connecting portion. The first connecting portion is electrically connected to the second conductive portion. One side of the second connecting portion is connected to the first connecting portion, and the other side of the second connecting portion extends toward the side of the cover plate body inside the operation hole. The tab of the battery cell is adapted to extend out of the cover plate body through the operation hole, and the side of the tab extending out of the cover plate body is bent toward the outer wall surface of the second connecting portion and is electrically connected to the second connecting portion.

[0010] Advantageous effects: When the cover plate assembly of this structure is used, it is disposed on the opening of the battery cell housing. The anti-rotation portion on the cover plate body cooperates with the mating portion on the second conductive portion to prevent the pole column from rotating relative to the cover plate body when the pole column is stressed. After the pole column is installed, it can be firmly held on the cover plate body, which can effectively ensure the stability of the cover plate assembly and the battery cell. At the same time, the connecting piece is disposed inside the cover plate body in parallel with the cover plate body. When the connecting piece is electrically connected to the pole column, the tab extends out of the cover plate body through the operation hole, and then the tab is bent toward the outer wall surface of the second connecting portion through the operation hole, and the bent portion of the tab is electrically connected to the second connecting portion to realize the electrical connection between the tab and the connecting piece. The cover plate assembly can be supplied as a component, that is, the connecting piece is directly connected to the pole column for supply. The bending process of the connecting piece is omitted during the manufacturing process of the battery cell. After the tab is bent, it is attached to the outer wall surface of the second connecting portion. The connecting piece extends horizontally in parallel with the cover plate assembly, which can effectively reduce the space occupied by the bending of the connecting piece and the tab in the height of the battery cell, and can make full use of the space inside the housing to set a pole group with a larger capacity, thereby improving the space utilization rate inside the battery cell and the volume energy density of the battery cell.

[0011] In an optional embodiment, a protruding portion is provided on the inner wall surface of the cover plate body on the side of the pole column mounting hole. The anti-rotation portion includes a first flat portion provided on the side of the protruding portion facing the pole column mounting hole, and the mating portion includes a second flat portion provided on the outer periphery of the second conductive portion.

[0012] In an alternative embodiment, the cross-section of the cover body is rectangular, and the two pole mounting holes are located on both sides of the cover body in the length direction; there are two operation holes, and the two operation holes are arranged at intervals between the two pole mounting holes; the poles include a positive pole and a negative pole, the pole tabs include a positive pole tab and a negative pole tab, the connecting piece includes a positive connecting piece and a negative connecting piece, the first connecting portion of the positive connecting piece is electrically connected to the second conductive portion of the positive pole, and the first connecting portion of the negative connecting piece is electrically connected to the second conductive portion of the negative pole; the positive pole and the negative pole are respectively arranged in the two pole mounting holes, the positive pole tab is adapted to extend out through the operation hole close to the positive pole and then bend towards the outer wall surface of the second connecting portion of the positive connecting piece, and the negative pole tab is adapted to extend out through the operation hole close to the negative pole and then bend towards the outer wall surface of the second connecting portion of the negative connecting piece.

[0013] Advantages: By providing two operation holes on the cover body and arranging the two operation holes at intervals, structures such as a liquid injection hole or an explosion-proof valve can be provided on the cover body between the two operation holes. In addition, compared with the structure of providing a through operation hole between the two pole mounting holes, while satisfying the pole tabs extending out from the operation holes, bending the pole tabs through the operation holes and connecting the pole tabs with the connecting piece, the opening area of the cover body can be reduced, the structural strength of the cover assembly can be improved, and thus the overall strength of the battery cell can be improved.

[0014] In an alternative embodiment, a liquid injection hole is provided in the middle of the cover body, and the two operation holes are symmetrically arranged on both sides of the liquid injection hole.

[0015] In an alternative embodiment, the distance between the side of the operation hole facing the liquid injection hole and the liquid injection hole is greater than 3.6 mm.

[0016] In an alternative embodiment, the distance between the edge of the operation hole along the width direction of the cover body and the edge of the cover body in the width direction is W1, and the width of the cover body is W, and W1≥0.15W.

[0017] In an alternative embodiment, a sealing plate is further included, the sealing plate is hermetically arranged on the operation hole, and the sealing plate is welded to the cover body; the distance between the side of the operation hole facing the first insulating member and the first insulating member is greater than 1.5 mm.

[0018] In a second aspect, the present invention further provides a battery cell, including:

[0019] A housing with one end open;

[0020] The electrode group is disposed inside the housing, and an electrode tab is provided on one side of the electrode group facing the open end of the housing.

[0021] The cover plate assembly according to any one of the above, the cover plate assembly is disposed on the opening; the electrode tab extends out of the cover plate body through the operation hole, and one side of the electrode tab extending out of the cover plate body is bent toward the outer wall surface of the second connecting portion and electrically connected to the second connecting portion. The battery cell includes a cover plate assembly and has the same technical effects as the cover plate assembly, which will not be elaborated here.

[0022] In an optional embodiment, a pressure relief structure is provided on the side wall of the housing opposite to the cover plate body.

[0023] In a third aspect, the present invention further provides a battery pack, including the battery cell according to any one of the above. The battery pack includes a cover plate assembly and has the same technical effects as the cover plate assembly, which will not be elaborated here. Description of the Drawings

[0024] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 A three-dimensional structure diagram of a cover plate assembly according to an embodiment of the present invention;

[0026] Figure 2 A top view of a cover plate assembly according to an embodiment of the present invention;

[0027] Figure 3 For Figure 2 The A-A cross-sectional view of;

[0028] Figure 4 For Figure 3 The partial enlarged view of part A in;

[0029] Figure 5 For Figure 1 The schematic diagram of the pole column in;

[0030] Figure 6 A three-dimensional structure diagram of a battery cell according to an embodiment of the present invention;

[0031] Figure 7 A top view of a battery cell according to an embodiment of the present invention;

[0032] Figure 8 For Figure 7Cross-sectional view taken along line B-B;

[0033] Figure 9 Schematic diagram of the tab protruding from the cover assembly during the assembly process of a battery cell according to an embodiment of the present invention;

[0034] Figure 10 Schematic diagram of a battery cell according to an embodiment of the present invention after the tab is welded to the connecting piece;

[0035] Figure 11 Schematic diagram of the cooperation of the electrode group, the connecting piece, and the tab in a battery cell according to an embodiment of the present invention;

[0036] Figure 12 Schematic diagram of the tab after being bent when the electrode group, the connecting piece, and the tab cooperate in a battery cell according to an embodiment of the present invention.

[0037] Explanation of reference numerals:

[0038] 1. Cover assembly; 11. Cover body; 111. Operation hole; 112. Protrusion; 1121. Anti-rotation part; 113. Liquid injection hole; 12. First insulating part; 13. Second insulating part; 14. Terminal; 141. First conductive part; 142. Second conductive part; 1421. Matching part; 15. Connecting piece; 151. First connecting part; 152. Second connecting part; 16. Sealing plate; 2. Housing; 3. Electrode group; 4. Tab; 5. Pressure relief structure. Detailed implementation manners

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0040] The cover assembly 1 is disposed on the housing 2 of the battery cell. The side of each component on the cover body 11 facing the outside of the housing 2 is referred to as the outside, and the side of each component on the cover body 11 facing the inside of the housing 2 is referred to as the inside.

[0041] Next, in combination with Figures 1 to 12 , the embodiments of the present invention will be described.

[0042] According to an embodiment of the present invention, on the one hand, a cover assembly 1 is provided, which includes a cover body 11, a first insulating part 12, a second insulating part 13, a terminal 14, and a connecting piece 15.

[0043] Among them, two pole post mounting holes and an operation hole 111 are provided on the cover plate body 11; an anti-rotation portion 1121 is provided on the cover plate body 11; the first insulating member 12 is disposed on the outer wall surface of the cover plate body 11; the second insulating member 13 is disposed on the inner wall surface of the cover plate body 11; the pole post 14 is disposed in the pole post mounting hole, and the pole post 14 includes a first conductive portion 141 and a second conductive portion 142. The first end of the first conductive portion 141 extends into the pole post mounting hole, and the second end of the first conductive portion 141 is press-connected to the first insulating member 12; the second conductive portion 142 is connected to the first end of the first conductive portion 141, and a mating portion 1421 is provided on the second conductive portion 142, and the mating portion 1421 cooperates with the anti-rotation portion 1121 to prevent the pole post 14 from rotating relative to the cover plate body 11; the connecting piece 15 is disposed parallel to the cover plate body 11 inside the cover plate body 11, and the connecting piece 15 includes a first connecting portion 151 and a second connecting portion 152. The first connecting portion 151 is electrically connected to the second conductive portion 142. One side of the second connecting portion 152 is connected to the first connecting portion 151, and the other side of the second connecting portion 152 extends toward the side of the operation hole 111 facing the inside of the cover plate body 11; the pole ear 4 of the battery cell is adapted to extend out of the cover plate body 11 through the operation hole 111, and the side of the pole ear 4 extending out of the cover plate body 11 is bent toward the outer wall surface of the second connecting portion 152 and is electrically connected to the second connecting portion 152.

[0044] When the cover plate assembly 1 of this structure is in use, it is disposed on the opening of the battery cell housing 2. The anti-rotation portion 1121 on the cover plate body 11 cooperates with the mating portion 1421 on the second conductive portion 142 to prevent the pole post 14 from rotating relative to the cover plate body 11 when the pole post 14 is stressed. After the pole post 14 is installed, it can be firmly held on the cover plate body 11, which can effectively ensure the stability of the cover plate assembly 1 and the battery cell. At the same time, the connecting piece 15 is disposed parallel to the cover plate body 11 inside the cover plate body 11. When the connecting piece 15 is electrically connected to the pole post 14, the pole ear 4 extends out of the cover plate body 11 through the operation hole 111, and then the pole ear 4 is bent toward the outer wall surface of the second connecting portion 152 through the operation hole 111, and the bent portion of the pole ear 4 is electrically connected to the second connecting portion 152 to realize the electrical connection between the pole ear 4 and the connecting piece 15. The cover plate assembly 1 can be supplied as an assembly, that is, the connecting piece 15 is directly connected to the pole post 14 for supply. In the manufacturing process of the battery cell, the bending process of the connecting piece 15 is omitted. After the pole ear 4 is bent, it is attached to the outer wall surface of the second connecting portion 152. The connecting piece 15 extends horizontally in parallel with the cover plate assembly 1, which can effectively reduce the space occupied by the bending of the connecting piece 15 and the bending of the pole ear 4 in the height of the battery cell, and can make full use of the space inside the housing 2 to set a pole group 3 with a larger capacity, thereby improving the space utilization rate inside the battery cell and the volume energy density of the battery cell.

[0045] Such as Figure 3 and Figure 4As shown, in some embodiments, the first conductive part 141 is cylindrical, and the pole post mounting hole is circular. A limiting part is provided at the end of the first conductive part 141. The diameter of the limiting part is larger than the diameter of the first conductive part 141 inside it. The limiting part is crimped on the first insulating part 12, thereby fixing the first insulating part 12 on the cover plate body 11. On the inner wall surface of the cover plate body 11 on the side of the pole post mounting hole, there is a protruding part 112. The anti-rotation part 1121 includes a first flat part provided on the side of the protruding part 112 facing the pole post mounting hole. The mating part 1421 includes a second flat part provided on the outer periphery of the second conductive part 142. The first flat part and the second flat part are in planar cooperation, which can effectively limit and fix the pole post 14 on the cover plate body 11.

[0046] In other embodiments, the anti-rotation part 1121 may further include a boss protruding from the cover plate body 11 on the side facing the pole post mounting hole. The mating part 1421 includes a groove provided on the second conductive part 142 of the pole post 14. The groove and the boss are in snap-fit to prevent the pole post 14 from rotating relative to the cover plate body 11.

[0047] As Figure 4 shown, at the position corresponding to the protruding part 112 on the second insulating part 13, there is an avoidance groove. The protruding part 112 is arranged in the avoidance groove. The second insulating part 13 surrounds the side of the protruding part 112 facing the pole post mounting hole to play an insulating and isolating role between the cover plate body 11 and the pole post 14.

[0048] In some embodiments, the cover plate assembly 1 further includes a sealing part. The sealing part is sleeved outside the first conductive part 141, and the sealing part plays a sealing role between the cover plate body 11 and the pole post 14.

[0049] In some embodiments, the cross-section of the cover plate body 11 is rectangular, and the cover plate body 11 has a long side and a wide side. The battery cell includes a square shell battery cell, as Figure 6As shown in the figure, the x-direction is referred to as the length direction of the battery cell, the y-direction is referred to as the thickness direction of the battery cell, and the z-direction is referred to as the height direction of the battery cell. The length direction of the cover body 11 extends along the x-direction, and the width direction of the cover body 11 extends along the y-direction. The two pole post mounting holes are located on both sides of the length direction of the cover body 11; there are two operation holes 111, and the two operation holes 111 are arranged at intervals between the two pole post mounting holes; the pole post 14 includes a positive pole post and a negative pole post, the tab 4 includes a positive tab and a negative tab, the connecting piece 15 includes a positive connecting piece and a negative connecting piece, the first connecting portion 151 of the positive connecting piece is electrically connected to the second conductive portion 142 of the positive pole post, and the first connecting portion 151 of the negative connecting piece is electrically connected to the second conductive portion 142 of the negative pole post; the positive pole post and the negative pole post are respectively arranged in the two pole post mounting holes, the positive tab is adapted to be bent toward the outer wall surface of the second connecting portion 152 of the positive connecting piece after extending out through the operation hole 111 close to the positive pole post, and the negative tab is adapted to be bent toward the outer wall surface of the second connecting portion 152 of the negative connecting piece after extending out through the operation hole 111 close to the negative pole post. By providing two operation holes 111 on the cover body 11 and arranging the two operation holes 111 at intervals, structures such as a liquid injection hole 113 or an explosion-proof valve can be provided on the cover body 11 between the two operation holes 111. In addition, compared with the structure of providing a through operation hole 111 between the two pole post mounting holes (i.e., Figure 1 also opening the area between the two slot holes in the figure to connect the two operation holes 111), while satisfying the requirements that the tab 4 extends out from the operation hole 111, the tab 4 is bent through the operation hole 111, and the tab 4 is connected to the connecting piece 15, the opening area of the cover body 11 can be reduced, and the structural strength of the cover assembly 1 can be improved, thereby improving the overall strength of the battery cell.

[0050] In some embodiments, the second conductive portion 142 is welded to the first connecting portion 151, and the tab 4 is welded to the second connecting portion 152, which can effectively ensure the electrical connection stability between the pole post 14 and the connecting piece 15, and between the tab 4 and the connecting piece 15.

[0051] As Figure 1 and Figure 2 shown, in some embodiments, a liquid injection hole 113 is provided in the middle of the cover body 11, and the two operation holes 111 are symmetrically arranged on both sides of the liquid injection hole 113. The liquid injection hole 113 is provided on the cover body 11 and located in the middle of the cover body 11, which is convenient for measuring and positioning other structures by extending from the liquid injection hole 113 as the center and positioning reference to both sides on the production line.

[0052] Optionally, in some embodiments, the distance between the side of the operation hole 111 facing the liquid injection hole 113 and the liquid injection hole 113 is greater than 3.6 mm. After the battery cell is assembled, electrolyte is injected into the battery cell through the liquid injection hole 113. After the electrolyte injection is completed, part of the electrolyte will remain on the cover body 11 in the area around the liquid injection hole 113, and a cleaning tooling is required to clean the remaining electrolyte. The area between the operation hole 111 and the liquid injection hole 113 is used to place the cleaning tooling for the operation of the cleaning tooling. The distance between the side of the operation hole 111 facing the liquid injection hole 113 and the liquid injection hole 113 is greater than 3.6 mm, so that the distance between the two is moderate, and it can be avoided that the distance between the two is too small to interfere with the operation of the cleaning tooling.

[0053] In some embodiments, the distance between the edge of the operation hole 111 along the width direction of the cover body 11 and the edge of the cover body 11 along the width direction is W1, and the width of the cover body 11 is W, and W1≥0.15W. Such a setting can ensure that there is enough solid part of the cover body 11 on both sides of the operation hole 111 along the width direction of the cover body 11, so as to ensure the strength of the cover body 11.

[0054] In some embodiments, such as Figure 6 and Figure 7 As shown, the cover assembly 1 further includes a sealing plate 16. The sealing plate 16 is sealingly arranged on the operation hole 111. The sealing plate 16 is welded to the cover body 11. The sealing plate 16 seals the pole ear 4 and the connecting piece 15 inside the cover body 11. Since the sealing plate 16 is welded to the cover body 11, the heat during the welding process will be transferred to the adjacent first insulating part 12, resulting in the melting and failure of the first insulating part 12. To avoid this problem, in the present invention, the distance between the side of the operation hole 111 facing the first insulating part 12 and the first insulating part 12 is greater than 1.5 mm, so that a proper distance is maintained between the side of the first insulating part 12 facing the operation hole 111, and the welding heat during the welding of the sealing plate 16 is prevented from causing the melting of the first insulating part 12, which can effectively ensure the insulating effect of the first insulating part 12.

[0055] According to an embodiment of the present invention, on the other hand, a battery cell is further provided, including a housing 2, a pole group 3 and the above-mentioned cover assembly 1.

[0056] Wherein, one end of the housing 2 is open; the pole group 3 is arranged inside the housing 2, and a pole ear 4 is arranged on the side of the pole group 3 facing the open end of the housing 2; the cover assembly 1 is arranged on the opening; the pole ear 4 extends out of the cover body 11 through the operation hole 111, and the side of the pole ear 4 extending out of the cover body 11 is bent towards the outer wall surface of the second connecting part 152 and is electrically connected to the second connecting part 152.

[0057] For the battery cell with such a structure, the anti-rotation part 1121 on the cover plate body 11 cooperates with the mating part 1421 on the second conductive part 142 to prevent the pole column 14 from rotating relative to the cover plate body 11 when stressed, which can effectively ensure the stability of the cover plate assembly 1 and the battery cell. At the same time, it can effectively reduce the space occupied by the bending of the connecting piece 15 and the pole ear 4 in the height direction of the battery cell, and the space inside the housing 2 can be fully utilized to set a pole group 3 with a larger capacity, thereby improving the space utilization rate inside the battery cell and the volume energy density of the battery cell.

[0058] Optionally, in some embodiments, as Figure 5 shown, a pressure relief structure 5 is provided on the side wall of the housing 2 opposite to the cover plate body 11. The liquid injection hole 113 is provided on the cover plate body 11, and the pressure relief structure 5 is provided at the bottom of the housing 2 so that the pressure relief structure 5 is away from the liquid injection hole 113, which can avoid the electrolyte contaminating the pressure relief structure 5 during liquid injection and is beneficial to improving the safety performance of the battery.

[0059] Optionally, in some embodiments, the pressure relief structure 5 is centrally provided at the bottom of the housing 2. The pressure relief structure 5 includes an explosion-proof valve.

[0060] According to an embodiment of the present invention, on the other hand, a battery pack is further provided, including the above-mentioned battery cell.

[0061] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A cover plate assembly, characterized in that: include: A cover plate body, wherein two pole mounting holes and an operation hole are provided on the cover plate body; an anti-rotation portion is provided on the cover plate body; A first insulating member, arranged on the outer wall surface of the cover body; A second insulating member is arranged on the inner wall surface of the cover body; A pole, arranged in the pole mounting hole, the pole comprising a first conductive part and a second conductive part, the first end of the first conductive part extends into the pole mounting hole, the second end of the first conductive part is crimped onto the first insulating member; the second conductive part is connected to the first end of the first conductive part, a matching part is provided on the second conductive part, the matching part cooperates with the anti-rotation part to prevent the pole from rotating relative to the cover body; A connecting piece is arranged on the inner side of the cover body in parallel with the cover body, and the connecting piece includes a first connecting part and a second connecting part, the first connecting part is electrically connected to the second conductive part, one side of the second connecting part is connected to the first connecting part, and the other side of the second connecting part extends toward the operating hole toward the inside of the cover body; the pole ear of the battery cell is suitable for extending out of the cover body through the operating hole, and the side of the pole ear extending out of the cover body is bent toward the outer wall surface of the second connecting part and is electrically connected to the second connecting part.

2. The cover plate assembly according to claim 1, characterized in that: A protrusion is provided on the inner wall surface of the cover body at the side of the pole mounting hole, the anti-rotation portion includes a first planar portion provided on the side of the protrusion facing the pole mounting hole, and the matching portion includes a second planar portion provided on the outer periphery of the second conductive portion.

3. The cover plate assembly according to claim 1 or 2, characterized in that: The cross-section of the cover body is rectangular, and the two pole mounting holes are located on both sides of the length direction of the cover body; there are two operation holes, and the two operation holes are spaced between the two pole mounting holes; the pole includes a positive pole and a negative pole, the pole ear includes a positive pole ear and a negative pole ear, the connecting piece includes a positive connecting piece and a negative connecting piece, the first connecting portion of the positive connecting piece is electrically connected to the second conductive portion of the positive pole, and the first connecting portion of the negative connecting piece is electrically connected to the second conductive portion of the negative pole; the positive pole and the negative pole are respectively arranged in the two pole mounting holes, the positive pole ear is suitable for extending through the operation hole close to the positive pole and then bending toward the outer wall surface of the second connecting portion of the positive pole connecting piece, and the negative pole ear is suitable for extending through the operation hole close to the negative pole and then bending toward the outer wall surface of the second connecting portion of the negative pole connecting piece.

4. The cover plate assembly according to claim 3, characterized in that: A liquid injection hole is provided in the middle of the cover body, and the two operation holes are symmetrically arranged on both sides of the liquid injection hole.

5. The cover plate assembly according to claim 4, characterized in that: The distance between the side of the operation hole facing the injection hole and the injection hole is greater than 3.6 mm.

6. The cover plate assembly according to claim 3, characterized in that: A distance between an edge of the operation hole in a width direction of the cover body and an edge of the cover body in the width direction is W1, a width of the cover body is W, and W1≥0.15W.

7. The cover plate assembly according to claim 1 or 2, characterized in that: It also includes a sealing plate, which is sealingly arranged on the operating hole and welded to the cover body; the distance between the side of the operating hole facing the first insulating member and the first insulating member is greater than 1.5 mm.

8. A battery cell, characterized in that: include: A shell having an opening at one end; A pole group is arranged in the shell, and a pole ear is arranged on one side of the pole group facing the opening end of the shell; The cover plate assembly according to any one of claims 1 to 7, wherein the cover plate assembly is arranged on the opening; the pole ear extends out of the cover plate body through the operating hole, and the side of the pole ear extending out of the cover plate body is bent toward the outer wall surface of the second connecting part and is electrically connected to the second connecting part.

9. The battery cell according to claim 8, characterized in that: A pressure relief structure is provided on a side wall of the shell body opposite to the cover plate body.

10. A battery pack, characterized in that: Comprising the battery cell as claimed in claim 8 or 9.

Images