Lower plastic plate, cover plate assembly and battery cell

Abstract

The utility model provides a lower plastic plate, a cover plate assembly and a battery cell. The lower plastic plate comprises two sub-plate bodies and a clamping structure, wherein the two sub-plate bodies are respectively provided with pole mounting holes, and the clamping structure is arranged between the two sub-plate bodies; the clamping structure comprises a clamping part arranged on one sub-plate body and a clamping matching part arranged on the other sub-plate body, the clamping part and the clamping matching part can be connected in a clamping mode in the thickness direction of the lower plastic plate, and the two sub-plate bodies are spliced into one plate body; and in a clamping state, the two sub-plate bodies can relatively move along the length direction of the lower plastic plate, so that the distance between the two pole mounting holes is adjustable. According to the lower plastic plate disclosed by the utility model, the two sub-plate bodies are clamped and connected in the thickness direction of the lower plastic plate through the clamping structures, and the two sub-plate bodies can relatively move along the length direction of the lower plastic plate, so that the distance between the two pole mounting holes can be adjusted, and the phenomenon that the pole is easy to shift after being mounted due to deformation of the lower plastic plate can be prevented; and the internal insulation effect of the battery core is poor.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a lower plastic plate; meanwhile, the utility model also relates to a cover plate assembly provided with the lower plastic plate, and a battery core provided with the cover plate assembly. Background Art

[0002] As a key part of the battery, the power battery cover is an important component of the battery cell structure, and plays the role of sealing, fixing and insulation. A typical power battery includes a shell, a cover assembly for closing the shell opening, and the cover assembly includes a pole, an aluminum sheet and a lower plastic plate connected to the aluminum sheet. There are pole mounting holes on the aluminum sheet and the lower plastic plate. In order to achieve insulation between the pole and the aluminum sheet, as well as sealing inside and outside the battery cell, a sealing ring is also installed on the pole. When the cover assembly is assembled as a whole, the pole passes through the lower plastic plate, the sealing ring and the pole mounting hole on the aluminum sheet in turn, and is used for electrical connection between the battery cell and external electrical devices.

[0003] After injection molding, the lower plastic plate is affected by thermal expansion and contraction, and the size and pole hole position are prone to change. When the cover plate is assembled, the pole and the lower plastic plate will deviate, causing the lower plastic plate to be skewed, affecting the insulation film wrapped around the pole group. In severe cases, the insulation film may even be wrinkled and torn, affecting the insulation performance of the battery cell. In addition, the assembled lower plastic plate will change in size due to thermal expansion and contraction, which will affect the central symmetry with the pole, causing the pole to shift, and in severe cases, it will cause poor sealing of the sealing ring. Utility Model Content

[0004] In view of this, the utility model aims to provide a lower plastic plate to facilitate adjusting the distance between two pole mounting holes, thereby facilitating improving the installation accuracy of the pole.

[0005] In order to achieve the above object, the technical solution of the utility model is implemented as follows:

[0006] A lower plastic plate comprises two sub-plate bodies respectively having pole mounting holes, and a clamping structure arranged between the two sub-plate bodies; the clamping structure comprises a clamping portion arranged on one of the sub-plate bodies, and a clamping matching portion arranged on the other sub-plate body, the clamping portion and the clamping matching portion can be clamped and connected along the thickness direction of the lower plastic plate, so that the two sub-plate bodies are spliced ​​into one plate body; in the clamped state, the two sub-plate bodies can move relatively along the length direction of the lower plastic plate, so that the spacing between the two pole mounting holes can be adjusted.

[0007] Furthermore, the snap-fitting portion includes a snap-fitting joint provided on one of the split-board bodies; the snap-fitting mating portion includes a snap-fitting hole provided on the other split-board body, and the snap-fitting hole is extended along the length direction of the lower plastic plate.

[0008] Furthermore, the end of one of the split plate bodies is provided with a protrusion protruding out of the split plate body, and the clamping joint is provided on the protrusion; and / or, the end of the other split plate body is provided with two protrusions protruding out of the split plate body, and the two protrusions are spaced apart in the width direction of the lower plastic plate; the two protrusions are provided with an elastic frame on one side facing each other, the clamping hole is formed between the two elastic frames, and the clamping joint is clamped on at least one of the elastic frames.

[0009] Furthermore, the clamping joint is in a "T" shape and can be clamped on the two elastic frames.

[0010] Furthermore, the elastic frame is in a "convex" shape, and the engaging hole is defined between the protruding parts of the two elastic frames.

[0011] Furthermore, at least one of the sub-plate bodies is provided with a positioning protrusion arranged along the circumference of the pole mounting hole, the positioning protrusion defines a positioning groove arranged in accordance with the bottom plate of the pole, and the bottom plate is positioned in the positioning groove.

[0012] Furthermore, at least one of the sub-plate bodies is provided with a first ventilation groove arranged along the circumference of the pole mounting hole, and a second ventilation groove connected to the first ventilation groove and penetrating the positioning protrusion along the radial direction of the first ventilation groove.

[0013] Furthermore, one of the sub-plate bodies is provided with a first recessed portion corresponding to the explosion-proof valve, and a plurality of first through holes are penetrated through the bottom surface of the first recessed portion; and / or, at least one of the free ends of the sub-plate bodies is provided with a second recessed portion recessed into the battery cell, and a plurality of second through holes are penetrated through the bottom surface of the second recessed portion.

[0014] Compared with the prior art, the utility model has the following advantages:

[0015] The lower plastic plate described in the utility model has two divided plate bodies that are connected by a clamping structure in the thickness direction of the lower plastic plate, and the two divided plate bodies can move relatively along the length direction of the lower plastic plate, which is beneficial to adjusting the spacing between the two pole mounting holes, thereby preventing the poles from being easily offset after installation due to deformation of the lower plastic plate and the occurrence of poor insulation effect inside the battery cell, which is beneficial to ensuring the performance of the battery cell.

[0016] In addition, the first clamping joint and the clamping hole extending along the length direction of the lower plastic plate are conducive to maintaining the clamping state when the two sub-plates move relative to each other along the length direction of the lower plastic plate, thereby improving the use effect of the lower plastic plate. The setting of the protrusion is conducive to the arrangement of the clamping joint, and the structure of the protrusion is simple and easy to process and form; elastic frames are respectively set on the two protrusions on one side facing each other, and a clamping hole is formed between the two elastic frames, which is conducive to the forming of the clamping hole. When the clamping joint is clamped into the clamping hole, the deformation of the elastic frame allows the clamping joint to pass through the clamping hole smoothly and be clamped on the elastic frame. The clamping joint is in a "T" shape and can be clamped on the two elastic frames, which is conducive to improving the clamping firmness of the clamping joint and the clamping hole.

[0017] In addition, the elastic frame is in a "convex" shape, and a snap-in hole is defined between the protruding parts of the two elastic frames, which further facilitates the elastic deformation of the elastic frame, and the structure of the elastic frame is simple and easy to arrange and implement. The positioning groove is defined by the positioning protrusion, which facilitates the positioning of the bottom plate of the pole on the lower plastic plate, thereby improving the installation accuracy of the pole. The provision of the first ventilation groove and the second ventilation groove facilitates the gas generated in the battery cell to stay away from the pole, thereby facilitating the improvement of the safety of the sealing structure at the pole. The provision of the first recessed portion and the first through hole facilitates the discharge of the gas generated by thermal runaway of the battery cell through the explosion-proof valve, thereby facilitating the safety of the battery cell; the provision of the second recessed portion and the second through hole facilitates the electrolyte to flow back from the outside of the lower plastic plate to the inside of the battery cell.

[0018] In addition, another object of the utility model is to provide a cover plate assembly, including a cover plate and the lower plastic plate as described above, which is arranged on the inner side of the cover plate, and the cover plate is provided with a through hole for the pole to pass through, and each of the pole mounting holes is arranged one by one corresponding to the through hole.

[0019] The cover plate assembly described in the utility model is beneficial to the alignment of the through hole and the pole mounting hole by adjusting the distance between the two pole mounting holes on the lower plastic plate, thereby ensuring the installation accuracy and installation stability of the pole on the lower plastic plate and the cover plate.

[0020] Furthermore, the utility model also provides a battery cell, the shell of which is provided with the cover plate assembly as described above.

[0021] The battery cell of the utility model is beneficial to improving the performance of the battery cell by arranging the above-mentioned cover plate assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the accompanying drawings:

[0023] Figure 1This is a schematic structural diagram of the lower plastic plate described in an embodiment of the utility model at one viewing angle;

[0024] Figure 2 This is a schematic structural diagram of the lower plastic plate described in an embodiment of the utility model from another viewing angle;

[0025] Figure 3 A bottom view of the lower plastic plate according to an embodiment of the utility model;

[0026] Figure 4 for Figure 3 AA direction section view;

[0027] Figure 5 It is a structural schematic diagram of the first sub-board body described in an embodiment of the utility model at one viewing angle;

[0028] Figure 6 It is a structural schematic diagram of the first sub-board body described in an embodiment of the utility model at another viewing angle;

[0029] Figure 7 It is a structural schematic diagram of the second sub-board body described in an embodiment of the utility model at one viewing angle;

[0030] Figure 8 This is a schematic structural diagram of the second sub-board body according to an embodiment of the utility model at another viewing angle;

[0031] Fig. 9 It is an exploded view of the cover plate assembly described in an embodiment of the utility model.

[0032] Description of reference numerals:

[0033] 1. First sub-board; 2. Second sub-board; 3. Cover plate; 4. Pole block; 5. Pole column;

[0034] 100, pole mounting hole; 101, protrusion; 102, liquid hole; 103, positioning column; 104, first recessed portion; 105, first through hole; 106, second recessed portion; 107, first ventilation groove; 108, second ventilation groove; 109, second through hole; 110, clamping joint; 111, positioning protrusion;

[0035] 200, snap-in hole; 201, bump; 202, elastic frame;

[0036] 301, explosion-proof valve installation hole; 302, injection hole; 303, through hole; 304, positioning hole; 305, installation groove;

[0037] 401, insulating sleeve;

[0038] 501, bottom plate; 502, column; 503, sealing ring. DETAILED DESCRIPTION

[0039] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0040] In the description of the present invention, it should be noted that if there are terms indicating orientation or positional relationship such as "upper", "lower", "inner", "back", etc., they are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention 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 invention. In addition, if there are terms such as "first", "second", etc., they are also used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0041] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0042] The present embodiment relates to a lower plastic plate, which comprises two sub-plate bodies each having a pole mounting hole 100, and a clamping structure disposed between the two sub-plate bodies. The clamping structure comprises a clamping portion disposed on one of the sub-plate bodies, and a clamping mating portion disposed on the other sub-plate body, wherein the clamping portion and the clamping mating portion can be clamped and connected along the thickness direction of the lower plastic plate, thereby splicing the two sub-plate bodies into one plate body. In the clamping state, the first sub-plate body 1 and the second sub-plate body 2 can move relative to each other along the length direction of the lower plastic plate, so that the spacing between the two pole mounting holes 100 can be adjusted.

[0043] The lower plastic plate described in this embodiment has two sub-plate bodies that are connected by a clamping structure in the thickness direction of the lower plastic plate, and the two sub-plate bodies can move relatively along the length direction of the lower plastic plate, which is beneficial to adjust the spacing between the two pole mounting holes 100, thereby preventing the pole 5 from being easily offset after installation due to deformation of the lower plastic plate, and preventing the occurrence of poor insulation effect inside the battery cell, thereby ensuring the performance of the battery cell.

[0044] Based on the above overall introduction, the structure of the lower plastic plate in this embodiment is as follows Figures 1 to 4 In order to distinguish the two sub-board bodies, the sub-board body provided with the snap-fitting part is referred to as the first sub-board body 1, and the sub-board body provided with the snap-fitting part is referred to as the second sub-board body 2. At the same time, the side of the lower plastic plate facing the cover plate 3 is referred to as the outer side, and the side facing the inside of the battery cell is referred to as the inner side.

[0045] As a preferred embodiment, Figures 4 to 8As shown in , the clamping part includes a clamping joint 110 provided on the first sub-board body 1; the clamping matching part includes a clamping hole 200 provided on the second sub-board body 2, and the clamping hole 200 is extended along the length direction of the lower plastic plate. Among them, the first clamping joint 110 and the clamping hole 200 extending along the length direction of the lower plastic plate are conducive to maintaining the clamping state when the first sub-board body 1 and the second sub-board body 2 move relative to each other along the length direction of the lower plastic plate, thereby improving the use effect of the lower plastic plate.

[0046] To facilitate the arrangement of the card connector 110, as Figure 5 and Figure 6 As shown in , the end of the first sub-board body 1 is provided with a protrusion 101 protruding outwardly toward the second sub-board body 2, and the clamping joint 110 is provided on the protrusion 101. The protrusion 101 is preferably located in the middle of the first sub-board body 1, and the clamping joint 110 has an arm body connected to the protrusion 101 and extending inwardly along the thickness direction of the lower plastic plate, and a head connected to the free end of the arm body. The setting of the protrusion 101 here is conducive to the arrangement of the clamping joint 110, and the structure of the protrusion 101 is simple and easy to process and form. Further, the arm body and the head are both extended along the length direction of the lower plastic plate to increase the clamping strength with the clamping hole 200.

[0047] like Figure 7 and Figure 8 As shown in , the end of the second sub-board body 2 is provided with two protrusions 201 protruding outwardly from the first sub-board body 1, and the two protrusions 201 are spaced apart in the width direction of the lower plastic plate. The two protrusions 201 are provided with elastic frames 202 on the sides facing each other, and a snap-in hole 200 is formed between the two elastic frames 202, and the snap-in joint 110 is snap-in on at least one of the elastic frames 202. Here, elastic frames 202 are respectively provided on the sides facing each other on the two protrusions 201, and a snap-in hole 200 is formed between the two elastic frames 202, which is conducive to the molding of the snap-in hole 200, and when the snap-in joint 110 is snapped into the snap-in hole 200, the elastic frame 202 is deformed so that the snap-in joint 110 can smoothly pass through the snap-in hole 200 and be snap-in on the elastic frame 202.

[0048] The elastic frame 202 in this embodiment is preferably in a "convex" shape, and a snap-in hole 200 is defined between the protruding parts of the two elastic frames 202. Such a setting is conducive to further improving the elastic deformation effect of the elastic frame 202, and the structure of the elastic frame 202 is simple and easy to arrange and implement. In addition, the snap-in joint 110 is in a "T" shape and can be snap-connected to the two elastic frames 202, which is conducive to improving the snap-in firmness of the snap-in joint 110 and the snap-in hole 200. In specific implementation, the elastic frame 202 is preferably integrally formed with the second sub-plate body 2 to improve processing efficiency. The material of the first sub-plate body 1 and the second sub-plate body 2 is the same as the material of the lower plastic plate in the prior art, and both are made of plastic.

[0049] In the card connection state, Figure 4 As shown in , when the clamping joint 110 is clamped and connected with the clamping hole 200, the protrusion 101 abuts against the outside of the two protrusions 201, and the two protrusions 201 are constrained between the protrusion 101 and the head of the clamping joint 110, so that the two sub-plate bodies cannot move relative to each other in the thickness direction of the lower plastic plate, thereby ensuring the structural strength between the lower plastic plates. When the two sub-plate bodies slide relative to each other according to the installation requirements of the pole 5, when the arm body of the clamping joint 110 can slide along the clamping hole 200, the clamping effect between the two sub-plates can be ensured, thereby improving the performance of the lower plastic plate.

[0050] In a specific implementation, when the clamping joint 110 in the clamping state is centrally arranged in the clamping hole 200 , the maximum displacement that can be moved to the left and right sides is preferably 0.8 mm, which is conducive to ensuring the spacing adjustment effect between the two pole mounting holes 100 .

[0051] As a preferred embodiment, at least one of the sub-plates is provided with a positioning protrusion 111 arranged along the circumference of the pole mounting hole 100, and the positioning protrusion 111 defines a positioning groove arranged in accordance with the bottom plate 501 of the pole 5, and the bottom plate 501 is positioned in the positioning groove. The positioning protrusion 111 defines the positioning groove, which facilitates the bottom plate 501 of the pole 5 to be positioned on the lower plastic plate, thereby improving the installation accuracy of the pole 5.

[0052] In terms of specific structure, Figure 2 As shown in , the inner sides of the first sub-board body 1 and the second sub-board body 2 are both provided with the above-mentioned positioning protrusions 111. The positioning groove is arranged in accordance with the bottom plate 501, which specifically means that the shape and specification of the cross section of the positioning groove are adapted to the shape and specification of the cross section of the bottom plate 501, so that the bottom plate 501 positioned in the positioning groove cannot rotate relative to the lower plastic plate, thereby facilitating the improvement of the installation accuracy of the pole 5 and the performance of the battery cell.

[0053] In addition, in this embodiment, at least one of the sub-plates is provided with a first ventilation groove 107 arranged along the circumference of the pole mounting hole 100, and a second ventilation groove 108 connected to the first ventilation groove 107 and arranged along the radial direction of the first ventilation groove 107 and penetrating the positioning protrusion 111. The provision of the first ventilation groove 107 and the second ventilation groove 108 is conducive to the gas generated in the battery cell to be away from the pole 5, thereby improving the safety of the sealing structure at the pole 5.

[0054] As a feasible implementation method, Figure 2As shown in , both sub-plates are provided with a first ventilation groove 107 and a second ventilation groove 108. To further improve the exhaust efficiency, the second ventilation grooves 108 in this embodiment are multiple and spaced apart along the circumference of the first ventilation groove 107. The gas generated by the electrolyte can flow through the first ventilation groove 107 and the second ventilation groove 108 in sequence and be discharged from the pole 5, which can prevent the gas from reacting with the sealing structure sleeved on the pole 5 and affecting the performance of the sealing structure, thereby ensuring the insulation effect between the pole 5 and the cover plate 3.

[0055] like Figure 1 As shown in , the length of the first sub-board body 1 is greater than that of the second sub-board body, and the explosion-proof valve is arranged corresponding to the first sub-board body 1. Preferably, a first recessed portion 104 corresponding to the explosion-proof valve is arranged on the first sub-board body 1, and a plurality of first through holes 105 are arranged through the bottom surface of the first recessed portion 104. The arrangement of the first recessed portion 104 and the first through holes 105 here is conducive to improving the discharge of the gas generated by the thermal runaway of the battery cell through the explosion-proof valve, thereby ensuring the safety of the battery cell. Of course, when the length of the second sub-board body 2 is greater than that of the first sub-board body 1, and the explosion-proof valve is arranged correspondingly on the second sub-board body 2, the first recessed portion 104 can be arranged on the second sub-board body 2.

[0056] In addition, both sub-plates are provided with a second recessed portion 106 that is recessed into the battery cell, and a plurality of second through holes 109 are formed through the bottom surface of the second recessed portion 106. The second recessed portion 106 and the second through holes 109 facilitate the electrolyte to flow back from the outer side of the lower plastic plate to the inside of the battery cell. Figure 1 and Figure 2 As shown in the figure, the free ends of the first sub-board body 1 and the second sub-board body 2 are both provided with a second recessed portion 106, which is conducive to ensuring the reflux efficiency of the electrolyte, and has a simple structure and is easy to arrange and implement. Of course, it is also feasible to provide the second recessed portion 106 on only one of the sub-board bodies.

[0057] In addition, corresponding to the injection hole 302 on the cover plate 3, a liquid through hole 102 corresponding to the injection hole 302 is provided on the first sub-plate body 1 to facilitate the injection of electrolyte. Figure 1 As shown in , positioning posts 103 are provided on the outer side of each sub-plate body and are arranged on both sides of the pole mounting hole 100. By inserting the positioning posts 103 into the corresponding positioning holes 304 of the cover plate 3, the lower plastic plate can be positioned on the cover plate 3, thereby facilitating the assembly efficiency of the lower plastic plate.

[0058] When the lower plastic plate in this embodiment is in use, the first sub-plate body 1 and the second sub-plate body 2 are first clamped together, and then the two are driven to move relative to each other along the length direction of the lower plastic plate, so that the positioning holes 304 of the two poles 5 are symmetrically arranged and aligned with the corresponding through holes 303 on the cover plate 3, and then the lower plastic plate can be fixed to the inner side of the cover plate 3 as the poles 5 are installed.

[0059] The lower plastic plate of the present embodiment optimizes the traditional one-piece lower plastic plate structure into two separate plate bodies, and enables the two separate plate bodies to move relatively along the length direction of the lower plastic plate while being connected by snapping, so that the spacing between the two pole mounting holes 100 is adjustable, and can compensate for the deviation caused by the deformation of the lower plastic plate, thereby helping to avoid the problem that the size of the one-piece lower plastic plate and the hole position of the pole 5 are easily changed in the prior art, and the pole 5 and the lower plastic plate will deviate when the cover plate 3 is assembled, resulting in the lower plastic plate being skewed and affecting the poor insulation of the battery cell. It can also avoid the problem that the change in the size of the lower plastic plate affects the central symmetry with the pole 5, thereby causing the pole 5 to deviate and affect the sealing insulation, thereby helping to ensure the safety of the battery cell.

[0060] In addition, the present embodiment also relates to a cover plate assembly, including a cover plate 3 and a lower plastic plate as above arranged on the inner side of the cover plate 3, and the cover plate 3 is provided with a through hole 303 for the pole 5 to pass through, and each pole mounting hole 100 is arranged in a one-to-one correspondence with the through hole 303.

[0061] In terms of specific structure, Fig. 9 As shown in , the through holes 303 are located at both ends of the cover plate 3, and the middle part of the cover plate 3 is provided with an explosion-proof valve mounting hole 301, which is arranged corresponding to the first recessed portion 104 up and down, for installing the explosion-proof valve. A liquid injection hole 302 is provided between the through hole 303 and the explosion-proof valve mounting hole 301, and the liquid injection hole 302 is arranged one-to-one with the liquid through hole 102 on the lower plastic plate. Mounting grooves 305 arranged one-to-one corresponding to the through holes 303 are respectively provided on the outer side of the cover plate 3, and the pole block 4 is positioned in the mounting groove 305. An insulating sleeve 401 is provided on the outer shell of the pole block 4, and it can be positioned in the mounting groove 305 through the insulating sleeve 401. The through hole 303 and the above-mentioned positioning column 103 are arranged through the bottom of the mounting groove 305.

[0062] After the position adjustment of the pole mounting hole 100 is completed, the column 502 passes through the pole mounting hole 100 on the lower plastic plate and the through hole 303 on the cover plate 3 from the inside to the outside in turn and is riveted to the corresponding pole block 4, so that the installation of the lower plastic plate on the cover plate 3 is completed. In addition, a sealing ring 503 is also sleeved on the outside of the column 502, and the sealing ring 503 is used for the insulation setting between the cover plate 3 and the column 502. The cover plate 3 and the lower plastic plate stacked together are sandwiched between the pole block 4 and the bottom plate 501 of the pole 5.

[0063] The cover plate assembly described in this embodiment facilitates the alignment of the through hole 303 and the pole mounting hole 100 by adjusting the distance between the two pole mounting holes 100 on the lower plastic plate, thereby ensuring the installation accuracy and installation stability of the pole 5 on the lower plastic plate and the cover plate 3.

[0064] In addition, the present embodiment also relates to a battery cell, the shell of which is provided with the above-mentioned cover plate assembly. The battery cell described in the present embodiment is provided with the above-mentioned cover plate assembly, which is beneficial to improving the performance of the battery cell.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A lower plastic plate, characterized in that: It comprises two sub-plate bodies each having a pole mounting hole, and a clamping structure arranged between the two sub-plate bodies; The clamping structure includes a clamping portion provided on one of the sub-plate bodies, and a clamping matching portion provided on the other sub-plate body, wherein the clamping portion and the clamping matching portion can be clamped and connected along the thickness direction of the lower plastic plate, so as to splice the two sub-plate bodies into one plate body; In the clamped state, the two sub-plate bodies can move relatively along the length direction of the lower plastic plate, so that the distance between the two pole mounting holes can be adjusted.

2. The lower plastic plate according to claim 1, characterized in that: The clamping part includes a clamping joint provided on one of the sub-plate bodies; The snap-fitting part comprises a snap-fitting hole provided on the other split plate body, and the snap-fitting hole is extended along the length direction of the lower plastic plate.

3. The lower plastic plate according to claim 2, characterized in that: One end of the split board body is provided with a protrusion protruding outward from the split board body, and the clamping joint is provided on the protrusion; and / or, The end of the other split plate body is provided with two protrusions protruding outward from the split plate body, and the two protrusions are spaced apart in the width direction of the lower plastic plate; An elastic frame is provided on one side of the two protrusions facing each other, a clamping hole is formed between the two elastic frames, and the clamping joint is clamped on at least one of the elastic frames.

4. The lower plastic plate according to claim 3, characterized in that: The card connector is in a "T" shape and can be card-connected to the two elastic frames.

5. The lower plastic plate according to claim 3, characterized in that: The elastic frame is in a "convex" shape, and the clamping hole is defined between the protruding parts of the two elastic frames.

6. The lower plastic plate according to claim 1, characterized in that: At least one of the sub-plate bodies is provided with a positioning protrusion arranged along the circumference of the pole mounting hole, the positioning protrusion defines a positioning groove arranged in accordance with the bottom plate of the pole, and the bottom plate is positioned in the positioning groove.

7. The lower plastic plate according to claim 6, characterized in that: At least one of the sub-plate bodies is provided with a first ventilation groove arranged along the circumference of the pole mounting hole, and a second ventilation groove communicated with the first ventilation groove and arranged to penetrate the positioning protrusion along the radial direction of the first ventilation groove.

8. The lower plastic plate according to any one of claims 1 to 7, characterized in that: One of the sub-plates is provided with a first recessed portion corresponding to the explosion-proof valve, and a plurality of first through holes are formed through the bottom surface of the first recessed portion; and / or, A second recessed portion recessed into the battery core is provided at the free end of at least one of the sub-plate bodies, and a plurality of second through holes are provided through the bottom surface of the second recessed portion.

9. A cover plate assembly, characterized in that: It comprises a cover plate and a lower plastic plate as claimed in any one of claims 1 to 8 arranged on the inner side of the cover plate, and the cover plate is provided with a through hole for the pole to pass through, and each of the pole mounting holes is arranged in one-to-one correspondence with the through hole.

10. A battery cell, characterized in that: The shell of the battery cell is provided with the cover plate assembly described in claim 9.

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