CN219717064U - Battery cell cover plate and battery cell - Google Patents

Abstract

The utility model discloses a battery cell cover plate and a battery cell, comprising: the cover plate body is provided with a pole mounting hole; the sealing insulation structure is connected with the cover plate body and is at least partially positioned in the pole mounting hole; the pole penetrates through the pole mounting hole and is spaced apart from the cover plate body in an insulating mode through the sealing insulation structure, the pole comprises a first limiting portion and a second limiting portion, the first limiting portion is limited and pressed on one side, deviating from the inside of the battery cell, of the sealing insulation structure, and the second limiting portion is suitable for being limited and pressed on the sealing insulation structure after the cover plate body is extruded and molded on one side, facing the inside of the battery cell, of the cover plate body. According to the battery core cover plate provided by the embodiment of the utility model, the two ends of the pole are respectively pressed against the upper side and the lower side of the cover plate body provided with the sealing insulation structure by extruding the part of the pole protruding out of the pole mounting hole, so that the fixing effect of the pole and the cover plate body is realized, the process is simple, the operation is convenient, the stability after fixing is strong, and the pressure resistance of the pole can be improved.

Description

Battery cell cover plate and battery cell

Technical Field

The utility model relates to the technical field of batteries, in particular to a battery cell cover plate and a battery cell with the battery cell cover plate.

Background

The lithium ion battery is widely applied to various industries due to the mature technology. The cover plate of the general lithium ion power battery consists of a cover plate body, a pole column, an explosion-proof valve and other structures, and the pole column is required to be stably fixed on the cover plate body and is not in electrical contact with the cover plate body. Therefore, in the prior art, the riveting block is mostly adopted and fixed by a laser welding mode, but the method has the problems of complicated process and poor welding, so that the manufacturing cost of the battery cell cover plate is high, and the phenomenon of unstable structure exists, so that the improvement space exists.

Disclosure of Invention

The present utility model aims to solve at least one of the technical problems existing in the prior art. Therefore, an object of the present utility model is to provide a battery cell cover plate, which simplifies the manufacturing process and ensures the overall structural stability of the battery cell cover plate.

According to an embodiment of the utility model, a battery cell cover plate comprises: the cover plate body is provided with a pole mounting hole; the sealing insulation structure is connected with the cover plate body and is at least partially positioned in the pole mounting hole; the pole is arranged in the pole mounting hole in a penetrating mode and is insulated and spaced from the cover plate body through the sealing insulation structure, the pole comprises a first limiting portion and a second limiting portion, the first limiting portion is limited and pressed on one side, deviating from the inside of the battery cell, of the sealing insulation structure, and the second limiting portion is suitable for being limited and pressed on the sealing insulation structure after the cover plate body is pressed and formed on one side, facing the inside of the battery cell, of the cover plate body.

According to the battery core cover plate disclosed by the embodiment of the utility model, the partial polar column protruding out of the polar column mounting hole is extruded to enable the partial polar column to be stressed to deform and be propped against the sealing insulation structure, namely, the shape of the polar column is directly changed, so that the two ends of the polar column are respectively propped against the upper side and the lower side of the cover plate body provided with the sealing insulation structure, the fixing effect of the polar column and the cover plate body is realized, the process is simple, the operation is convenient, the stability after the fixing is strong, and the pressure resistance of the polar column can be improved.

The manufacturing cost is reduced, and meanwhile, the processing mode is simple and easy to operate, so that the production efficiency is improved.

According to the battery cell cover plate provided by the embodiment of the utility model, the sealing insulation structure comprises the first plastic, the sealing element and the second plastic which are sequentially distributed along the axial direction of the pole, wherein the first plastic and the sealing element are both arranged at the pole mounting hole, and the second plastic is positioned at one side of the cover plate body facing the inside of the battery cell and is connected with the sealing element; the first limiting part is limited to be propped against the first plastic, and the second limiting part is limited to be propped against the second plastic.

According to the battery cell cover plate provided by the embodiment of the utility model, the pole further comprises a main body part, the main body part sequentially penetrates through the first plastic, the sealing piece and the second plastic piece, the first limiting part is positioned on the outer peripheral wall of one end of the main body part and extends outwards in the radial direction, and the second limiting part is positioned on the outer peripheral wall of the other end of the main body part and extends outwards in the radial direction after extrusion molding.

According to the battery cell cover plate provided by the embodiment of the utility model, the second limiting part is in an annular shape after extrusion molding, the sealing element is in a sealing ring, and the outer diameter of the second limiting part is smaller than or equal to the outer diameter of the sealing ring.

According to the battery cell cover plate provided by the embodiment of the utility model, the outer diameter of the second limiting part is a, the outer diameter of the sealing ring is b, and the requirements are satisfied: 0.5< a/b <1.

According to the battery cell cover plate provided by the embodiment of the utility model, the sealing element comprises the axial extension part and the radial extension part, the axial extension part is sleeved outside the main body part, the radial extension part is connected with one end of the axial extension part and extends outwards along the radial direction of the axial extension part, and the radial extension part is clamped between the cover plate body and the second plastic.

According to the embodiment of the utility model, the battery cell cover plate further comprises a positioning piece, wherein the first limiting part, the first plastic and the cover plate body are all provided with positioning holes, and the positioning piece is positioned and penetrated in the positioning holes.

According to the battery cell cover plate provided by the embodiment of the utility model, two positioning holes are arranged, and an included angle of 45 degrees is formed between the extending direction of a connecting line of the two positioning holes and the length direction of the cover plate body.

According to the battery cell cover plate provided by the embodiment of the utility model, the axial thickness of the second limiting part is smaller than that of the first limiting part.

The utility model also provides a battery cell, which comprises a pole group and the battery cell cover plate.

The battery cell and any of the above battery cell cover plates have the same advantages over the prior art, and are not described in detail herein.

Additional aspects and advantages of the utility model will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the utility model.

Drawings

The foregoing and/or additional aspects and advantages of the utility model will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:

fig. 1 is a structural exploded view of a cell cover plate according to an embodiment of the present utility model;

fig. 2 is a cross-sectional view of a cell cover plate according to an embodiment of the present utility model.

Reference numerals:

the cell cover plate 100,

the cover plate body 1, the pole mounting hole 11, the positioning groove 12,

the sealing insulation structure 2, the first plastic 21, the first flange 211, the sealing member 22, the axial extension 221, the radial extension 222, the second plastic 23, the connecting hole 231,

the pole 3, the first limit part 31, the main body part 32, the second limit part 33,

positioning piece 4 and positioning hole 5.

Detailed Description

Embodiments of the present utility model are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the utility model.

A cell cover 100 according to an embodiment of the present utility model is described below with reference to fig. 1-2, including: a cover plate body 1, a sealing insulation mechanism and a pole 3. It should be noted that, as shown in fig. 1, the cover plate body 1 is configured as a strip-shaped plate structure made of aluminum material, and a pole mounting hole 11 is provided on the cover plate, and meanwhile, the diameter of the pole mounting hole 11 is the same as the diameter of the pole 3, so as to achieve a fixing effect in cooperation with the pole 3.

And the sealing insulation structure 2 is connected with the cover plate body 1, and the connection stability of the cover plate body 1 and the sealing insulation structure 2 is guaranteed to be good, so that the sealing insulation structure 2 is prevented from falling off to lose the insulation protection effect.

The pole mounting hole 11 is also connected with a part of the structure of the sealing insulation structure 2, so that the inner wall of the pole mounting hole 11 and the adjacent end face thereof are covered by the sealing junction structure, thereby ensuring the insulation effect of the pole mounting hole 11. That is, in actual installation, after the sealing insulation structure 2 is installed and attached to the pole mounting hole 11, the pole 3 is inserted into the pole mounting hole 11, so that the sealing insulation structure 2 is connected between the pole 3 and the cover plate body 1, and the insulation effect of the pole 3 and the cover plate body 1 is achieved.

And, the pole 3 is provided with a cylindrical structure having the same diameter as the pole mounting hole 11, and the pole 3 is deformed when receiving pressure. In actual installation, the pole 3 is arranged in the pole mounting hole 11 in a penetrating manner, and meanwhile, pressure is applied to one end of the pole 3, which is arranged in the pole mounting hole 11 in a penetrating manner, so that the pole 3 deforms when being subjected to the pressure, and then the pole 3 is attached to the cover plate body 1 to achieve fixation.

Specifically, the pole 3 includes a first limiting portion 31 and a second limiting portion 33, where the first limiting portion 31 is limited to press against one side of the sealed insulation structure 2 facing away from the inside of the battery cell, and the second limiting portion 33 is adapted to press against the sealed insulation structure 2 after the cover plate body 1 is extruded to form one side facing the inside of the battery cell.

That is, the first limiting portion 31 is larger than the diameter of the pole mounting hole 11, that is, the first limiting portion 31 can only be pressed against the side of the sealed insulation structure 2 facing away from the inside of the battery cell, so that a portion of the pole 3 penetrating through the pole mounting hole 11 cannot fall out from the pole mounting hole 11. Simultaneously, the cover plate body 1 applies pressure towards one side of the inside of the battery cell, so that the pole 3 deforms when receiving the pressure, the deformed pole 3 forms a second limiting part 33, and the second limiting part 33 is propped against the sealing insulation structure 2. Thereby, the effect of fixing the pole 3 and the cover plate body 1 is achieved.

And, two identical pole mounting holes 11 may be provided on one cover plate body 1 to be respectively mounted in cooperation with two identical poles 3, and the two pole mounting holes 11 are symmetrically distributed at two ends of the cover plate body 1. Therefore, when the pole 3 is penetrated one by one into the pole mounting holes 11, the second limiting part 33 is formed by applying pressure to the pole 3, and the cover plate body 1, the sealing insulation structure 2 and the pole 3 are fixedly connected by extruding the cover plate body 1 through the first limiting part 31 and the second limiting part 33, so that the connecting effect is achieved.

That is, the present embodiment can directly dispense with the connecting member consumed by the fixing process such as the riveting and screwing, thereby reducing the weight of the cover plate body 11 and saving the manufacturing cost of the parts. Meanwhile, the extrusion fixing mode has the advantages of few process steps, simplicity in operation, capability of greatly shortening the processing time cost and improvement of the production efficiency.

According to the battery core cover plate 100 of the embodiment of the utility model, the electrode post 3 protruding out of the electrode post mounting hole 11 is extruded to deform and press against the sealing insulation structure 2, namely, the shape of the electrode post 3 is directly changed, so that two ends of the electrode post 3 are respectively pressed against the upper side and the lower side of the cover plate body 1 provided with the sealing insulation structure 2, and the fixing effect of the electrode post 3 and the cover plate body 1 is realized. In the process, a connecting piece is not required to be used for realizing the fixing effect, the number of parts of the whole battery cell cover plate 100 can be reduced, the structure of the battery cell cover plate 100 is simplified, the manufacturing cost is reduced, meanwhile, the processing mode of the battery cell cover plate 100 is simple and easy to operate, the operation is convenient, the stability after fixing is strong, and the voltage-resistant capability of the pole 3 can be improved.

In some embodiments, the sealing insulation structure 2 comprises a first plastic 21, a sealing member 22 and a second plastic 23 which are sequentially distributed along the axial direction of the pole 3, wherein the first plastic 21 and the sealing member 22 are both arranged at the pole mounting hole 11, and the second plastic 23 is positioned at one side of the cover plate body 1 facing the inside of the battery cell and is connected with the sealing member 22;

it should be noted that, as shown in fig. 1, the cover plate body 1 surrounds the pole mounting hole 11, and a positioning slot 12 is further provided on a side facing away from the inside of the battery cell, and an axis of the positioning slot 12 is consistent with an axis of the pole mounting hole 11.

The first plastic 21 is configured as a ring structure, the inner diameter of the first plastic 21 is the same as the diameter of the pole mounting hole 11, an axial first flange 211 deviating from the inner direction of the battery cell is arranged at the peripheral wall, the diameter of the bottom surface of the first plastic 21 is the same as the diameter of the positioning groove 12, the first plastic 21 can be matched with the positioning groove 12, the first flange 211 is attached to the peripheral wall of the first limiting portion 31, and the bottom surface of the first plastic 21 abuts against the bottom surface of the first limiting portion 31. Thereby, the insulating effect of the first stopper 31 can be ensured.

And, sealing member 22 is laminated with the inside part utmost point post 3 of wearing to establish utmost point post mounting hole 11 for after utmost point post 3 is connected with utmost point post mounting hole 11, sealing member 22 can laminate with utmost point post 3 periphery wall, thereby guarantees that the part that utmost point post 3 worn to locate in the utmost point post mounting hole 11 does not contact with apron body 1.

And the second plastic 23 is configured into a strip-shaped structure with the same size as the cover plate body 1, the second plastic 23 is attached to one side of the cover plate body 1 facing the inner direction of the battery cell, the second plastic 23 is provided with a connecting hole 231, and the position of the connecting hole 231 is opposite to the pole mounting hole 11. Therefore, when the pole 3 passes through the pole mounting hole 11 with the sealed insulation structure 2, the part penetrating through the pole mounting hole 11 is pressed and attached to the second plastic 23, that is, the second limiting part 33 formed by the pole 3 is limited and pressed with the second plastic 23, so that the insulation effect of the second limiting part 33 is ensured.

That is, when the pole 3 is mounted, the first limiting portion 31 is limited against the first plastic 21, the second limiting portion 33 is limited against the second plastic 23, and a portion of the pole 3 located inside the pole mounting hole 11 is attached to the sealing member 22, and the entire pole 3 is not contacted with the cover plate body 1, so as to ensure insulation stability of the pole 3.

In some embodiments, the pole 3 further includes a main body portion 32, the main body portion 32 penetrates through the first plastic 21, the sealing member 22 and the second plastic 23 in sequence, the first limiting portion 31 is located at the outer peripheral wall of one end of the main body portion 32 and extends radially outwards, and the second limiting portion 33 is located at the outer peripheral wall of the other end of the main body portion 32 and extends radially outwards after extrusion molding.

That is, as shown in fig. 2, the post 3 is constituted by the first stopper 31, the main body 32, and the second stopper 33 together after the mounting, and the diameter of the main body 32 is the same as the diameter of the post mounting hole 11. In actual assembly, the main body 32 is attached to the sealing member 22, so that the main body 32 is ensured not to contact the cover plate body 1, and an insulating effect is achieved.

Specifically, the main body portion 32 is threaded through the pole mounting hole 11, and at this time, pressure is applied to the pole 3, so that the portion of the pole 3 threaded through the pole mounting hole 11 is deformed, and then the second limiting portion 33 is formed. The second limiting portion 33 is formed into a disc-shaped structure when being molded, and is abutted against the second plastic 23, the second limiting portion 33 is coaxial with the main body portion 32, but the diameter of the second limiting portion 33 is larger than that of the main body portion 32.

And, the first limiting portion 31 is also stressed to deform in the extrusion process, that is, the first limiting portion 31 can also extend radially relative to the axis, so that the contact area with the first plastic 21 is increased, and the connection strength is improved.

In some embodiments, the second limiting portion 33 is configured to be annular after extrusion, and the sealing member 22 is configured as a sealing ring, and an outer diameter of the second limiting portion 33 is smaller than or equal to an outer diameter of the sealing ring. It should be noted that, as shown in fig. 2, the sealing ring is disposed between the cover plate body 1 and the second limiting portion 33, the second limiting portion 33 and the sealing ring are in an annular structure when formed, and the contact between the second limiting portion 33 and the cover plate body 1 can be effectively isolated by setting the outer diameter of the sealing ring to be larger than the outer diameter of the second limiting portion 33, so as to achieve an insulation effect.

In some embodiments, the second limiting portion 33 has an outer diameter a, the sealing ring has an outer diameter b, and the following conditions are satisfied: 0.5< a/b <1. That is, as shown in fig. 2, the dimensional ratio of the outer diameter of the seal ring to the second stopper 33 satisfies: the outer diameter a of the extruded second limiting part 33 is larger than the outer diameter b of more than half of the sealing ring, namely, in the interval of 0.5< a/b <1, the contact area between the second limiting part 33 and the sealing ring is larger, and the pressure transferred to the sealing ring is also larger, so that the fixing effect of the pole 3 is better.

The sealing ring is required to be provided with a certain thickness to relieve the received pressure, so that the sealing ring still has a certain compression amount when receiving the pressure, and the situation that the sealing ring exceeds a limit to lose elasticity to cause cracks and influence the sealing effect is avoided.

In some embodiments, the sealing member 22 includes an axial extension 221 and a radial extension 222, the axial extension 221 is sleeved outside the main body 32, the radial extension 222 is connected to one end of the axial extension 221 and extends radially outwards along the axial extension 221, and the radial extension 222 is sandwiched between the cover plate body 1 and the second plastic 23. As shown in fig. 1, the seal 22 is configured as a seal ring, and the seal ring is in a ring structure, and extends axially along an inner diameter edge thereof to form an axial extension 221, and extends radially along an inner diameter edge thereof to form a radial extension 222. Wherein the length of the axial extension 221 is the same as the length of the main body 32, and the extension length of the radial extension 222 is large.

Therefore, when the sealing ring is sleeved on the main body 32, the axial extension 221 is attached to the main body 32, and insulation between the main body 32 and the cover plate body 1 can be ensured through the axial extension 221, so that an insulation protection effect is achieved. Meanwhile, the radial extension 222 has a larger extension distance, which can increase the contact area between the sealing element 22 and the cover plate body 1, and is beneficial to expanding the insulation area.

In some embodiments, the positioning piece 4 is further included, and the first limiting portion 31, the first plastic 21 and the cover plate body 1 are all provided with positioning holes 5, and the positioning piece 4 is positioned and penetrated through the positioning holes 5. That is, as shown in fig. 1, the positioning member 4 is provided with the positioning hole 5 to achieve the fixing effect, so as to avoid the unstable connection caused by the rotation of the pole 3.

Specifically, the positioning member 4 is made of an insulating material, and a ceramic column is selected as the positioning member 4 in this embodiment. Meanwhile, the same positioning holes 5 are arranged at the same positions on the first limiting part 31, the first plastic 21 and the cover plate body 1, so that the positioning holes 5 are ensured to be opposite to each other in the vertical direction. From this, wear to establish first spacing portion 31, first plastic 21 and the locating hole 5 on the apron body 1 with setting element 4 in proper order, utilize interference fit to make between setting element 4 and the locating hole 5 produce elastic pressure to obtain the connection of fastening, and then prevent that whole structure from taking place to rotate, guarantee stability.

In some embodiments, the number of the positioning holes 5 is two, and the extending direction of the connecting line of the two positioning holes 5 forms an included angle of 45 ° with the length direction of the cover plate body 1. That is, as shown in fig. 1, the two positioning holes 5 are symmetrically arranged around the pole mounting hole 11, so that the uniformity of stress of the pole 3 and the cover plate body 1 on two sides of the pole mounting hole 11 can be ensured, and the damage problem caused by overlarge stress on one side can be avoided. Meanwhile, the design that the length of the positioning hole 5 and the length of the cover plate body 1 are 45 degrees is favorable for transmitting the pressing force, so that the uniformity of force transmission is further improved, the stress on the pole 3, the cover plate body 1 and the second plastic 23 is more even, and the connecting effect is more stable.

In some embodiments, the axial thickness of the second stop 33 is less than the axial thickness of the first stop 31. It will be appreciated that, as shown in fig. 2, the second limiting portion 33 is an annular structure formed when the pole 3 is pressed, and in order to ensure the connection strength, the second limiting portion 33 is compressed to a size greater than half of the outer diameter of the seal ring. The larger the outer diameter of the second limiting portion 33 is, the shorter the axial thickness thereof is, and the first limiting portion 31 only plays a supporting role in the whole process, so that the compression amount of the first limiting portion 31 is smaller, that is, the axial thickness of the second limiting portion 33 is smaller than the axial thickness of the first limiting portion 31.

It should be noted that, in the present utility model, the battery cell cover 100 has a plurality of posts 3, as shown in fig. 2, two posts 3 are provided, one is a positive post 3, the other is a negative post 3, and the positive post 3 and the negative post 3 have the same structure and are connected and fixed with the cover body 1 by adopting the same structure.

The utility model further provides a battery cell.

A cell according to an embodiment of the present utility model comprises a pole group and a cell cover 100 according to any of the above. The electrode group and the battery core cover plate 100 are matched to form a battery core, wherein the battery core changes the connection mode of the electrode post 3 and the cover plate body 1, an annular second limiting part 33 is formed by directly extruding the end part of the electrode post 3, and the second limiting part 33 is abutted against the cover plate body 1 to realize clamping fit, so that the effect of fixing the electrode post 3 is achieved. Compared with other connection modes, the method has the advantages of small number of parts, contribution to saving of material cost, simple process flow and high production efficiency.

1. In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present utility model.

2. In the description of the utility model, a "first feature" or "second feature" may include one or more of such features.

3. In the description of the present utility model, "plurality" means two or more.

4. In the description of the utility model, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, and may also include the first and second features not being in direct contact but being in contact with each other by another feature therebetween.

5. In the description of the utility model, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature.

In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the utility model. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present utility model have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the utility model, the scope of which is defined by the claims and their equivalents.

Claims (10)

1. A cell cover plate, comprising:

the cover plate body is provided with a pole mounting hole;

the sealing insulation structure is connected with the cover plate body and is at least partially positioned in the pole mounting hole;

the pole is arranged in the pole mounting hole in a penetrating mode and is insulated and spaced from the cover plate body through the sealing insulation structure, the pole comprises a first limiting portion and a second limiting portion, the first limiting portion is limited and pressed on one side, deviating from the inside of the battery cell, of the sealing insulation structure, and the second limiting portion is suitable for being limited and pressed on the sealing insulation structure after the cover plate body is pressed and formed on one side, facing the inside of the battery cell, of the cover plate body.

2. The battery cell cover plate according to claim 1, wherein the sealing insulation structure comprises a first plastic, a sealing piece and a second plastic piece which are sequentially distributed along the axial direction of the pole, the first plastic and the sealing piece are both arranged at the pole mounting hole, and the second plastic is positioned at one side of the cover plate body facing the inside of the battery cell and is connected with the sealing piece;

the first limiting part is limited to be propped against the first plastic, and the second limiting part is limited to be propped against the second plastic.

3. The cell cover plate according to claim 2, wherein the terminal post further comprises a main body portion penetrating through the first plastic, the sealing member and the second plastic member in sequence, the first limiting portion being located at an outer peripheral wall of one end of the main body portion and extending radially outward, and the second limiting portion being located at an outer peripheral wall of the other end of the main body portion and extending radially outward after extrusion molding.

4. The cell cover plate according to claim 3, wherein the second limiting portion is configured to be annular after extrusion molding, the sealing member is configured as a sealing ring, and an outer diameter of the second limiting portion is smaller than or equal to an outer diameter of the sealing ring.

5. The cell cover plate according to claim 4, wherein the second limiting portion has an outer diameter a, the sealing ring has an outer diameter b, and the following conditions are satisfied: 0.5< a/b <1.

6. The cell cover plate of claim 3, wherein the sealing member comprises an axial extension portion and a radial extension portion, the axial extension portion is sleeved outside the main body portion, the radial extension portion is connected to one end of the axial extension portion and extends outwards along the radial direction of the axial extension portion, and the radial extension portion is sandwiched between the cover plate body and the second plastic.

7. The battery cell cover plate according to claim 2, further comprising a positioning piece, wherein the first limiting portion, the first plastic and the cover plate body are all provided with positioning holes, and the positioning piece is positioned and penetrated in the positioning holes.

8. The battery cell cover plate according to claim 7, wherein the number of the positioning holes is two, and the extending direction of the connecting line of the two positioning holes forms an included angle of 45 degrees with the length direction of the cover plate body.

9. The cell cover of claim 1, wherein an axial thickness of the second limiting portion is less than an axial thickness of the first limiting portion.

10. A cell characterized by a pole group and a cell cover as claimed in any one of claims 1-9.