CN219937074U - Pole lug stretching device and pole lug production system of pole piece - Google Patents

Abstract

The utility model discloses a pole lug stretching device and a pole lug production system of a pole piece, in particular to a pole piece, which comprises a dressing area and a pole lug area which are arranged at intervals, wherein the pole piece comprises a stretching roller, and the periphery of the stretching roller is provided with an annular groove; the pinch roller assembly comprises a driving piece and a pinch roller, wherein the pinch roller is connected with a power output end of the driving piece, the pinch roller is arranged above the annular groove, the driving piece is used for driving the pinch roller to be close to or far away from the annular groove so as to adjust the distance between the bottom surface of the pinch roller and the inner wall of the annular groove, and the tab area is pressed into the annular groove so as to be stretched. Therefore, the utility model solves the problem that the stretching force of the tab cannot be effectively adjusted in the prior art.

Description

Pole lug stretching device and pole lug production system of pole piece

Technical Field

The utility model relates to the technical field of batteries, in particular to a tab stretching device of a pole piece and a pole piece production system.

Background

In the production process of the secondary battery, the pole piece of the secondary battery needs to be rolled. The secondary battery is not limited to a lithium ion battery and a sodium ion battery, and the pole piece is provided with a dressing area and a tab area which are arranged at intervals. The rolling step is applied to the dressing area of the pole piece, and after the dressing area of the pole piece is coated with dressing and dried, the dressing is relatively loose and needs to be compacted by adopting a rolling device. Through the step, the pole piece with higher material area density, compact coating structure and better mechanical property can be obtained. Therefore, rolling plays a critical role in improving the battery capacity and stabilizing the electrode structure. However, in the pole piece rolling process, the dressing area can be directly contacted with the compression roller due to the thicker dressing area, so that the dressing area is extruded by the compression roller to generate a certain degree of extension, the size of the dressing area is larger than that of the tab area without dressing, and the extended dressing area can drive the tab area to deform due to the fact that the tab area and the dressing area are adjacently arranged, and then the defects of tab wrinkling and the like are generated. Extension of the dressing area is unavoidable because the dressing needs to be compacted. Therefore, the current production line mostly adopts the process of additionally stretching the tab, and in particular, the current production line provides a tab stretching device for the pole piece, so that the tab is stretched to the same extensibility as the dressing area, and the defect brought by pole piece rolling is reduced.

The main stream method for stretching the tab in the production line at present is to manually attach a teflon adhesive tape around the stretching roller at the external position corresponding to the tab area, and the effect is to increase the diameter of the part of the stretching roller so that the tab area contacts with the stretching roller structure and is additionally stressed. The thickness of the sticking layer is in direct proportion to the stretching force, and the stretching force is controlled by the thickness of the sticking layer so as to achieve the purpose of stretching the tab to a proper extensibility. The main defects are as follows:

the thickness of the adhesive layer is integer times of the standard thickness, which cannot be controlled accurately, and the thickness and the stretching force of the adhesive layer cannot be controlled accurately. It is difficult to handle when encountering specific pole piece thicknesses and tensile extensions.

In the production process, if the stretching is unqualified, when the tab stretching rate needs to be adjusted without stopping, the stretching tension is adjusted by adjusting each passing roller due to the complicated procedures of removing the teflon adhesive tape or rewinding the adhesive tape. At the moment, the tension of the whole pole piece production system, namely the dressing area, can also change together, so that the pole lug stretching process is unstable and uncontrollable.

In the production process, if the stretching is unqualified and the stretching tension cannot be adjusted, or the stretching tension cannot be adjusted due to other factors, the machine is stopped to adjust the thickness of the adhesive layer. The shutdown greatly influences the production efficiency and the yield. The hardness and strength of teflon are generally lower than those of the roll surface. When the elastic or plastic deformation is suffered from extrusion in the use process, the elastic or plastic deformation is likely to occur, and the magnitude and the accuracy of the stretching force are affected. The process of adjusting the Teflon laminating is purely manual operation, and personnel misoperation is easy to occur. Most of the existing patents are based on the basis of the Teflon laminating layer, and stretching roller or combined roller structures with different shapes are designed to replace the Teflon laminating layer. There is also a problem in that the tensile force cannot be effectively adjusted.

In summary, the tab stretching device of the pole piece in the prior art has the problem that the stretching force cannot be effectively adjusted.

Disclosure of Invention

The utility model provides a tab stretching device of a pole piece and a pole piece production system, and aims to solve the problem that the tab stretching device of the pole piece cannot effectively adjust stretching force in the prior art.

In order to solve the problems, the utility model provides a tab stretching device of a pole piece, wherein the pole piece comprises a dressing area and a tab area which are arranged at intervals, the tab stretching device comprises a stretching roller and a pinch roller assembly, and an annular groove is formed in the periphery of the stretching roller; the pinch roller subassembly includes driving piece and pinch roller, the pinch roller is connected the power take off end of driving piece, the pinch roller set up in the ring channel top, the driving piece is used for the drive the pinch roller is close to or keeps away from the ring channel to adjust the pinch roller bottom surface with interval between the ring channel inner wall, and in pressing in the ring channel with the utmost point ear district in order to make the utmost point ear district stretched.

In an embodiment, the pole piece comprises a plurality of dressing areas and pole lug areas which are sequentially arranged at intervals, the stretching roller is provided with a plurality of annular grooves which are in one-to-one correspondence with the pole lug areas, the annular grooves are axially arranged at intervals along the stretching roller, and the pole lug stretching device of the pole piece further comprises a plurality of pinch roller assemblies, and the pinch roller assemblies and the annular grooves are arranged in one-to-one correspondence.

In an embodiment, the tab stretching device of the pole piece further comprises a mounting rod, the mounting rod is arranged above the stretching roller, the extending direction of the mounting rod is parallel to the axial direction of the stretching roller, and the driving pieces are arranged on the mounting rod at intervals.

In an embodiment, the bottom surface of the pressing wheel and the inner wall of the annular groove are arranged in a circular arc shape, and the curvature of the bottom surface of the pressing wheel is larger than that of the inner wall of the annular groove.

In one embodiment, the annular groove has a depth of not less than 1mm and not more than 3mm.

In one embodiment, the driving member is a hydraulic cylinder.

The utility model also provides a pole piece production system, which comprises the pole lug stretching device of the pole piece, and further comprises a rolling device, wherein the rolling device is used for rolling a dressing area of the pole piece, and the rolling device and the pole lug stretching device of the pole piece are sequentially arranged along the transportation direction of the pole piece.

In an embodiment, the pole piece production system further comprises a detection device, the pole piece passes through the detection device after passing through the tab stretching device of the pole piece, and the detection device comprises an image collector.

In an embodiment, the pole piece production system further comprises a control device, wherein the control device is respectively connected with the detection device and the driving piece, and is used for receiving information transmitted by the detection device and controlling the driving piece to move according to the information so as to adjust the distance between the bottom surface of the pressing wheel and the inner wall of the annular groove.

The utility model provides a tab stretching device of a pole piece and a pole piece production system, and in particular relates to the tab stretching device of the pole piece, which comprises a stretching roller and a pinch roller assembly, wherein the stretching roller is provided with an annular groove; the pinch roller subassembly includes the pinch roller, the pinch roller set up in the ring channel top, the pinch roller is used for impressing the utmost point ear district in the ring channel so that the utmost point ear district is stretched, the pinch roller bottom surface with there is the clearance between the inner wall of ring channel, just the pinch roller bottom surface with the interval of the inner wall of ring channel is adjustable. The distance between the bottom surface of the pinch roller and the inner wall of the annular groove can be adjusted through the driving piece, so that the tensile force born by the pole lug area of the pole piece can be accurately adjusted. Therefore, the utility model solves the problem that the stretching force of the tab stretching device of the pole piece in the prior art cannot be effectively adjusted.

Drawings

FIG. 1 is a schematic structural view of a tab stretching device for pole pieces according to an embodiment of the present utility model;

FIG. 2 is a side view of the tab stretching device of the pole piece of FIG. 1;

fig. 3 is a schematic diagram of the pole piece production system of the present utility model.

Reference numerals	Name of the name	Reference numerals	Name of the name
				100	Pole piece production system	10	Tab stretching device of pole piece
11	Stretching roller	11a	Annular groove
				12	Pinch roller	13	Driving piece
14	Mounting rod	20	Rolling device
				21	First press roll	22	Second press roller
30	First pass roller	40	Second passing roller
				200	Pole piece	200a	Dressing region
200b	Lug area

Detailed Description

The following describes in further detail the embodiments of the present utility model with reference to the drawings and examples. The following examples are illustrative of the utility model and are not intended to limit the scope of the utility model.

In the description of the present utility model, it should be understood that the directions or positional relationships indicated by "front", "rear", "upper", "lower", "left", "right", "longitudinal", "transverse", "vertical", "horizontal", "top", "bottom", "inner", "outer", "head", "tail", etc. are configured and operated in a specific direction based on the directions or positional relationships shown in the drawings, are merely for convenience of description of the present utility model, and do not indicate that the apparatus or element referred to must have a specific direction, and thus should not be construed as limiting the present utility model.

In the production process of the secondary battery, the pole piece of the secondary battery needs to be rolled. The pole piece is provided with dressing areas and tab areas which are arranged at intervals. The rolling step is applied to the dressing area of the pole piece, and after the dressing area of the pole piece is coated with dressing and dried, the dressing is relatively loose and needs to be compacted by adopting a rolling device. Through the step, the pole piece with higher material area density, compact coating structure and better mechanical property can be obtained. Therefore, rolling plays a critical role in improving the battery capacity and stabilizing the electrode structure. However, in the pole piece rolling process, because the dressing area is thicker, the dressing area can be directly contacted with the compression roller for the dressing area is produced the extension of certain degree by the compression roller extrusion, leads to along the roll-in direction, and the length of dressing area is greater than the tab area length that does not have the dressing, and because tab area and dressing area are adjacent to set up, the dressing area that is extended can drive tab area deformation, and then produces defects such as tab wrinkling. Extension of the dressing area is unavoidable because the dressing needs to be compacted. Therefore, the current production line mostly adopts the process of additionally stretching the tab, and in particular, the current production line provides a tab stretching device for the pole piece, so that the tab is stretched to the same extensibility as the dressing area, and the defect brought by pole piece rolling is reduced.

The main stream method for stretching the tab in the production line at present is to manually attach a teflon adhesive tape around the stretching roller at the external position corresponding to the tab area, and the effect is to increase the diameter of the part of the stretching roller so that the tab contacts with the stretching roller structure and is additionally stressed. The thickness of the sticking layer is in direct proportion to the stretching force, and the stretching force is controlled by the thickness of the sticking layer so as to achieve the purpose of stretching the tab to a proper extensibility. The main defects are as follows: the thickness of the adhesive layer is a combination of the standard thickness, and the thickness and the tensile force of the adhesive layer cannot be accurately controlled. It is difficult to handle when encountering specific pole piece thicknesses and tensile extensions. Secondly, in the production process, if the stretching is unqualified, and the stretching rate of the tab needs to be adjusted without stopping, the stretching tension is generally adjusted. At the moment, the tension of the dressing area can also change together, so that the stretching process of the tab is unstable and uncontrollable. Meanwhile, in the production process, if the stretching is unqualified and the stretching tension cannot be adjusted, or the stretching tension cannot be adjusted due to other factors, the machine is stopped to adjust the thickness of the laminated layer. The shutdown greatly influences the production efficiency and the yield. The hardness and strength of teflon are generally lower than those of the roll surface. When the elastic or plastic deformation is suffered from extrusion in the use process, the elastic or plastic deformation is likely to occur, and the magnitude and the accuracy of the stretching force are affected. The process of adjusting the Teflon laminating is purely manual operation, and personnel misoperation is easy to occur.

Other schemes in the prior art are also mostly based on the basis of the Teflon adhesive layer, and stretching rollers or combined roller structures with different shapes are designed to replace the Teflon adhesive layer so as to directly stretch the tab area. Specifically, there is a problem that the tensile force cannot be effectively adjusted in this way. And if the stretching force is adjusted by adjusting the rotation speed of the roller, there are problems. First, the tension effect is not significant by adjusting the rotational speed, and in the case where the rotational speed is changed greatly, the tension may not be changed significantly. Simultaneously, the tension is adjusted like this, and the tension of whole pole piece, including the tension of auxiliary material district and utmost point ear district all can change. In most cases, it is desirable to change only the tension in the tab region when adjusting the amount of stretch. Furthermore, the speed of the pole piece is changed while the rotating speed is changed, and the speed of the pole piece is consistent with that of the whole rolling system. If the rotation speed is reduced, the tape running speed is directly reduced, and then the productivity is affected. The existing process technology may not meet such fast tape speeds if the rotational speed is increased, resulting in pole piece defects.

Referring to fig. 1 and 2, the present utility model proposes a tab stretching device 10 for a pole piece, where the pole piece 200 includes a dressing area 200a and a tab area 200b that are disposed at intervals, and includes a stretching roller 11 and a pinch roller assembly, and an annular groove 11a is formed on the periphery of the stretching roller 11; the pinch roller assembly comprises a pinch roller 12 and a driving piece 13, wherein the pinch roller 12 is arranged above the annular groove 11a, the pinch roller 12 is used for pressing the lug area 200b into the annular groove 11a so that the lug area 200b is stretched, and a power output end of the driving piece 13 is connected with the pinch roller 12 to drive the pinch roller 12 to be close to or far away from the annular groove 11a, so that the distance between the bottom surface of the pinch roller 12 and the inner wall of the annular groove 11a can be adjusted.

Specifically, in this embodiment, the stretching roller is designed as a stretching roller 11 with a groove, a pinch roller 12 is disposed above the stretching roller 11, the outer circumference of the stretching roller 11 is a cylinder with an annular groove 11a, and when the stretching roller 11 rotates around its own rotation axis, the pole piece 200 passes through the upper surface of the stretching roller 11. And tab area 200b of pole piece 200 corresponds to annular groove 11a of stretch roll 11. As tab area 200b passes through annular groove 11a, pinch roller 12 is pressed into annular groove 11a, causing tab area 200b to be stretched. Further, the distance between the bottom surface of the pinch roller 12 and the inner wall of the annular groove 11a can be adjusted, so that the depth of the lug area 200b pressed into the annular groove 11a can be adjusted, and the stretching force of the lug area 200b can be adjusted, thereby achieving the purpose of accurately and independently controlling the stretching force of the lug.

Further, before the tab stretching device 10 of the pole piece is started, the pinch roller 12 is adjusted to a preset position, and then the tab stretching device 10 of the pole piece is started. And the stretched tab area 200b is detected, and if the produced pole piece 200 meets shipment requirements, the distance between the bottom surface of the pinch roller 12 and the inner wall of the annular groove 11a does not need to be adjusted. Otherwise, the spacing is adjusted until the produced pole piece 200 meets the criteria. The pinch roller 12 is used as a stretching contact structure in the scheme, so that the problem that stretching defects are generated by deformation of Teflon in a traditional tab stretching method is solved, and the problem that stretching force is not easy to adjust by adopting a traditional stretching roller is also solved.

Specifically, for each pressing wheel 12, a driving member 13 is correspondingly disposed. The travel of the pinch roller 12 is controlled by the driving piece 13, so that the accuracy of the motion travel of the pinch roller 12 is improved, and the control of the stretching force in the tab stretching method is more accurate. In another embodiment, the pressing wheel 12 may also be detachably mounted, specifically, the tab stretching device further includes a mounting rod, the pressing wheel is detachably mounted on the mounting rod, the pressing wheel 12 has different mounting positions at different heights, and the mounting height of the pressing wheel 12 can be adjusted to adjust the distance between the pressing wheel 12 and the annular groove 11a.

In one embodiment, the driving member 13 is a hydraulic cylinder. Under the same precision requirement, the hydraulic cylinder has the advantages of better stability and lower cost. Specifically, in the operation process of the equipment, hydraulic oil is distributed into the hydraulic oil cylinders through the one-way valves and the overflow valves, the hydraulic oil cylinders move under the action of high-pressure oil, the hydraulic oil cylinders respectively and independently correspond to the pinch rollers 12, the pinch rollers 12 are independently pressurized by adjusting the pressure of the hydraulic oil, the distance between the pinch rollers 12 and the special-shaped stretching rollers is controlled, the purpose of controlling stretching tension is achieved, and the problems of tension adjustment, lug defects and the like in the stretching process of the lugs are solved. In another embodiment, the driving member 13 may be a motor, a cylinder, or the like.

Referring to fig. 1, in an embodiment, the stretching roller 11 is provided with a plurality of annular grooves 11a, a plurality of annular grooves 11a are disposed along the stretching roller 11 at intervals, and the tab stretching device 10 of the pole piece further includes a plurality of pinch roller assemblies, and a plurality of pinch roller assemblies and the annular grooves 11a are disposed in a one-to-one correspondence.

In particular, pole piece 200 has a plurality of tab regions 200b and a plurality of dressing regions 200a as an important part of the battery composition. The dressing regions 200a and tab regions 200b are continuously and alternately arranged. And the thickness of the dressing region 200a is different from that of the tab region 200b, thus rolling the dressing region 200a and stretching the tab region 200b into tabs, thereby forming the electrode sheet 200 required for battery production. To accommodate the plurality of tab areas 200b spaced apart, a plurality of annular grooves 11a are spaced apart along the axial direction of the tension roller 11. A pinch roller 12 is disposed above each annular groove 11a to effect individual stretching of each tab area 200 b. In one embodiment, independent precise adjustment of the tension in each tab area 200b is achieved for each puck 12 driven by a separate drive 13.

Referring to fig. 1, in an embodiment, the tab stretching device 10 of the pole piece further includes a mounting rod 14, the mounting rod 14 is disposed above the stretching roller 11, and an extending direction of the mounting rod 14 is parallel to an axial direction of the stretching roller 11, and a plurality of the pinch roller assemblies are disposed on the mounting rod 14 at intervals.

The mounting bar 14 is used to mount the puck 12 and drive 13. Further, a plurality of puck assemblies are spaced along mounting bar 14. Since the mounting rod 14 is parallel to the axial direction of the stretching roller 11, that is, the mounting rod 14 can ensure that the initial positions of the pressing wheels 12 are positioned at the same height, the distance between the bottom surface of the pressing wheel 12 and the inner wall of the annular groove 11a is controlled by controlling the movement stroke of the pressing wheels 12. Ensuring that each tab area 200b of pole piece 200 has a good stretching effect.

Referring to fig. 2, in an embodiment, the bottom surface of the pressing wheel 12 and the inner wall of the annular groove 11a are all disposed in a circular arc shape, and the curvature of the bottom surface of the pressing wheel 12 is greater than the curvature of the inner wall of the annular groove 11a.

The bottom surface of the pressing wheel 12 is arranged in a circular arc shape, so that the edge of the giant pressing wheel 12 which is too sharp is prevented from scraping the tab. Meanwhile, the annular groove 11a is an arc-shaped groove, namely, the inner wall of the annular groove 11a is an arc surface. This prevents the tab area 200b from being scratched by striking a sharp boundary when it is pressed down. Notably, the curvature of the bottom surface of puck 12 is greater than the curvature of the inner wall of annular groove 11a. I.e., the bottom surface of puck 12 is curved a little more than the arc surface of the inner wall of annular groove 11a. This arrangement is intended to prevent contact between the bottom surface of puck 12 and the arcuate surface of the inner wall of annular groove 11a when the amount of depression of puck 12 is relatively large. On this premise, the curvature of the bottom surface of puck 12 should be as small as possible, i.e., the curvature of the bottom surface of puck 12 should be as gentle as possible. This prevents tab area 200b from being scratched by striking a sharp boundary when puck 12 is depressed.

In one embodiment, the depth of the annular groove 11a is not less than 1mm and not more than 3mm. The depth of the annular groove 11a needs to be larger than the maximum pressing stroke of the pressing wheel 12, so that the contact between the bottom surface of the pressing wheel 12 and the inner wall of the annular groove 11a is avoided. Meanwhile, the depth of the annular groove 11a is set according to the desired stretching effect of the tab and the size of the stretched pole piece 200. In one embodiment, the depth of the annular groove 11a is 2mm. In another embodiment, puck 12 needs to face annular groove 11a. Specifically, the axis of symmetry of the pinch roller 12 coincides with the axis of symmetry of the annular groove 11a. And the width of puck 12 is less than the width of annular groove 11a. Further, the width of the left and right sides of the pinch roller 12 is 1mm smaller than that of the annular groove 11a.

Referring to fig. 3, the present utility model further provides a pole piece production system 100, including the pole tab stretching device 10 of the pole piece, where the pole piece production system 100 further includes a rolling device 20, the rolling device 20 is used for rolling the dressing area 200a of the pole piece 200, and the rolling device 20 and the pole tab stretching device 10 of the pole piece are sequentially disposed along the transportation direction of the pole piece 200.

The pole piece 200 sequentially passes through a rolling device 20 and a pole lug stretching device 10 of the pole piece along the conveying direction, the rolling device 20 is used for rolling a dressing area 200a of the pole piece 200, the pole piece comprises a first press roller 21 and a second press roller 22, the axes of the first press roller 21 and the second press roller 22 are arranged in parallel, the rotating speeds of the first press roller 21 and the second press roller 22 are the same, and the directions of the rotating speeds of the first press roller 21 and the second press roller are opposite, so that the pole piece 200 is used for rolling the dressing area 200a of the pole piece. And then the rolled pole piece 200 is directly input into the pole lug stretching device 10 of the pole piece, so that the pole lug area 200b is stretched, and the automation degree of the pole piece production system 100 is improved.

In an embodiment, the pole piece production system 100 further includes a first roller 30 and a second roller 40, where the rolling device 20, the first roller 30, the tab stretching device 10 of the pole piece, and the second roller 40 are sequentially disposed along the conveying direction of the pole piece 200, the first roller 30 is used for adjusting the conveying direction of the pole piece 200 after passing through the rolling device 20, and the second roller 40 is used for adjusting the conveying direction of the pole piece 200 after passing through the tab stretching device 10 of the pole piece, so as to implement automatic production. In the prior art, the stretching tension of the tab can also be adjusted by adjusting the positions of the first and second passing rollers 30, 40. However, by adjusting the tension in this way, the tension across pole piece 200, including the tension in dressing region 200a and tab region 200b, will vary. Most of the time, it is desirable to change only the tension of tab area 200 b.

Since the pole piece production system 100 of the present utility model has the same technical features as the pole tab stretching device 10 of the pole piece in any of the above embodiments, the same technical effects can be achieved, and the description thereof will not be repeated here.

In one embodiment, the pole piece production system 100 further includes a detecting device (not shown) through which the pole piece 200 passes after passing through the tab stretching device 10 of the pole piece, and the detecting device is configured to detect the stretching effect of the tab area 200 b. The detection device comprises an image collector.

In one embodiment, the detection device may be disposed between the tab stretching device 10 of the pole piece and the second roller 40. For detecting the stretching quality of the post-stretching tab region 200 b. In an embodiment, the detecting device may be an image collector, and observe the stretching effect of the tab through an image to determine whether the tab is wrinkled or not. In another embodiment, the detection device may be a CCD camera. In another embodiment, the quality of tab stretching can also be detected by visual inspection.

In an embodiment, the pole piece production system 100 further includes a control device (not shown in the figure), the pole tab stretching device 10 of the pole piece includes a driving member 13, the control device is respectively connected to the detecting device and the driving member 13, and the control device is configured to receive information transmitted by the detecting device, and control the driving member 13 to move according to the information, so as to adjust a distance between the bottom surface of the pinch roller 12 and an inner wall of the annular groove 11a.

Specifically, the control device receives the information transmitted by the detection device, and when the stretching effect of the tab is poor and the product is unqualified, the pole piece production system 100 is controlled to stop working in time. And the movement of the driving member 13 is controlled again according to the corresponding parameters, and the distance between the bottom surface of the pinch roller 12 and the inner wall of the annular groove 11a is adjusted. This parameter may also be entered manually. After readjusting the parameters, the pole piece production system 100 is controlled to resume production. In an embodiment, the detection device further comprises a signal transmitter, and the control device comprises a signal receiver for receiving a signal sent by the signal transmitter. The signal transmitter may be an acoustic wave transmitter, an optical signal transmitter or an electromagnetic wave transmitter, and the signal receiver may be an acoustic wave receiver, an optical signal receiver or an electromagnetic wave receiver, respectively.

The foregoing is merely a preferred embodiment of the present utility model, and it should be noted that modifications and substitutions can be made by those skilled in the art without departing from the technical principles of the present utility model, and these modifications and substitutions should also be considered as being within the scope of the present utility model.

Claims (9)

1. The utility model provides a pole piece's utmost point ear stretching device, the pole piece includes dressing district and the utmost point ear district that the interval set up, its characterized in that includes:

the outer periphery of the stretching roller is provided with an annular groove;

the pinch roller assembly comprises a driving piece and a pinch roller, wherein the pinch roller is connected with a power output end of the driving piece, the pinch roller is arranged above the annular groove, the driving piece is used for driving the pinch roller to be close to or far away from the annular groove so as to adjust the distance between the bottom surface of the pinch roller and the inner wall of the annular groove, and the lug area is pressed into the annular groove so as to be stretched.

2. The tab stretching device of the pole piece according to claim 1, wherein the pole piece comprises a plurality of dressing areas and tab areas which are sequentially arranged at intervals, a plurality of annular grooves which are used for being in one-to-one correspondence with the tab areas are formed in the stretching roller, the annular grooves are arranged at intervals along the axial direction of the stretching roller, the tab stretching device of the pole piece further comprises a plurality of pinch roller assemblies, and the pinch roller assemblies and the annular grooves are arranged in one-to-one correspondence.

3. The tab stretching device of the pole piece according to claim 2, further comprising a mounting rod, wherein the mounting rod is arranged above the stretching roller, the extending direction of the mounting rod is parallel to the axial direction of the stretching roller, and a plurality of driving pieces are arranged on the mounting rod at intervals.

4. The tab stretching device of the pole piece of claim 1, wherein the bottom surface of the pressing wheel and the inner wall of the annular groove are arranged in a circular arc shape, and the curvature of the bottom surface of the pressing wheel is larger than the curvature of the inner wall of the annular groove.

5. A tab stretching device for a pole piece as recited in claim 4, wherein the annular groove has a depth of not less than 1mm and not more than 3mm.

6. The tab stretching device of the pole piece of claim 1, wherein the driving member is a hydraulic cylinder.

7. A pole piece production system, characterized by comprising the pole piece lug stretching device according to any one of claims 1 to 6, the pole piece production system further comprises a rolling device, the rolling device is used for rolling a dressing area of a pole piece, and the rolling device and the pole piece lug stretching device are sequentially arranged along the transportation direction of the pole piece.

8. The pole piece production system of claim 7, further comprising a detection device through which the pole piece passes after passing through the tab stretching device of the pole piece, the detection device comprising an image collector.

9. The pole piece production system of claim 8, further comprising a control device, wherein the control device is respectively connected to the detection device and the driving member, and the control device is configured to receive information transmitted by the detection device and control the driving member to move according to the information, so as to adjust the distance between the bottom surface of the pressing wheel and the inner wall of the annular groove.