A lithium ion battery pole piece roll pressing and wrinkle eliminating device and eliminating method

Abstract

This invention relates to a device and method for eliminating wrinkles during the rolling process of lithium-ion battery electrodes. The device includes a wrinkle-eliminating mechanism that is positioned on both sides of the wrinkle-prone area of ​​the electrode, with the mechanism comprising a pressure wheel, a pulley, and a transmission belt fitted between the pressure wheel and the pulley. The transmission belt is pressed against the wrinkle-prone area of ​​the electrode by the pressure wheel and / or the pulley, and undergoes elastic deformation. The pulley serves as a drive wheel and is positioned in front of the pressure wheel along the electrode's movement direction. Compared with existing technologies, this invention effectively prevents wrinkles from forming on the electrode during the rolling process due to the difference in elongation between the coated area and the blank area, thereby facilitating the large-scale continuous production of this type of electrode and improving the efficiency and yield of electrode rolling production.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion battery electrode manufacturing technology, and relates to a device and method for eliminating roll forming wrinkles in lithium-ion battery electrodes. Background Technology

[0002] Lithium-ion batteries are widely used in electronic products, power tools, and electric vehicles. Currently, the manufacturing process of lithium-ion battery electrodes mainly includes processes such as slurry preparation, coating, drying, and rolling. To improve production efficiency, a "zebra coating" method is often used, where the current collector foil is coated in a zebra stripe pattern, creating multiple coated areas and uncoated blank areas alternating in the rolling direction. The coated and blank areas of the electrode differ in thickness and width, with the coated areas being thicker than the blank areas. During rolling, due to the significant thickness difference between the coated and blank areas, the pressure rollers can only roll the coated areas. After rolling, the active material in the coated areas is tightly compacted, reducing its thickness and causing a certain amount of stretching in the length direction. The foil in the blank areas, however, does not stretch in the length direction because it is not subjected to rolling pressure. This difference in stretching results in wrinkles at the boundary between the coated and blank areas, adversely affecting subsequent production processes and battery performance.

[0003] Currently, rolling processes include hot rolling and cold rolling. However, both methods result in wrinkles in the non-coated areas due to inconsistent stretching between the coated and uncoated areas. To address this, a common method is to manually apply Teflon tape to the rollers before and after the electrode rolling process. This ensures the roller surface in the uncoated area is higher than the coated area, achieving pre-stretching and post-stretching of the foil in the uncoated area to eliminate wrinkles. However, this method relies heavily on the operator's experience and skill, requires a long setup time, results in significant variations in wrinkle removal effectiveness, and the use of high tension easily leads to frequent tape breakage, impacting production efficiency.

[0004] Chinese patent CN109037589A discloses a lithium battery electrode rolling anti-wrinkle device and method. This technology includes simultaneously applying a protective film to both sides (AB and AB) of the electrode using a coating device. The disadvantages of this technology are that the thickness of the protective film is difficult to determine, the precise correspondence between the protective film and the width of the blank area is difficult to achieve, and the difference in mechanical properties between the protective film and the active material is not considered. Chinese patent CN115138683A discloses an electrode rolling equipment. This technology includes using calendering rollers and rolls to roll the blank area of ​​the electrode, causing the blank area to also extend to eliminate wrinkles and breakage. The disadvantages of this technology are that the foil thickness in the blank area is very small, calendering is difficult, resulting in high applied pressure and limited foil extension, which is not conducive to wrinkle elimination. Summary of the Invention

[0005] The purpose of this invention is to provide a device and method for eliminating wrinkles during the rolling process of lithium-ion battery electrode sheets, which is used to prevent wrinkles from forming on the electrode sheets due to the difference in the amount of extension between the coating area and the blank area during the rolling process. This is beneficial to meeting the requirements of large-scale continuous production of this type of electrode sheet and improving the production efficiency and yield of electrode sheet rolling.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A lithium-ion battery electrode roll forming wrinkle elimination device is provided between an unwinding device and a rolling device. It includes a wrinkle elimination mechanism that is relatively pressed between the two sides of the area where wrinkles are prone to occur on the electrode. The wrinkle elimination mechanism includes a pressing wheel, a pulley, and a transmission belt sleeved between the pressing wheel and the pulley.

[0008] The transmission belt is pressed against the area where the electrode wrinkles are prone to occur by a pressure wheel and / or a pulley, and undergoes elastic deformation; the pulley serves as a drive wheel and is located in front of the pressure wheel along the direction of electrode movement.

[0009] Furthermore, the transmission belt is a rubber transmission belt.

[0010] Furthermore, the transmission belt is a polyurethane transmission belt.

[0011] Furthermore, the belt drive is connected to the first drive device, and the pressure wheel drive is connected to the second drive device.

[0012] Furthermore, both the first driving device and the second driving device include a drive motor.

[0013] Furthermore, the wrinkle-eliminating mechanism also includes a mounting bracket, on which the pressure wheel and pulley are mounted.

[0014] Furthermore, the device also includes a base, on which a screw is provided perpendicular to the electrode plate, and the mounting bracket is provided with a clearance hole for the screw to pass through, and a fixing nut for threaded connection with the screw is provided in the clearance hole.

[0015] Furthermore, the device also includes a transition roller, a first tension cut-off roller pair, a first tension adjusting roller, a first tension detecting roller, and a first guide roller arranged sequentially between the unwinding device and the wrinkle elimination mechanism along the electrode moving direction, and a second guide roller, a second tension detecting roller, a second tension adjusting roller, a second tension cut-off roller pair, a third tension adjusting roller, a third tension detecting roller, and a third guide roller arranged sequentially between the wrinkle elimination mechanism and the rolling device along the electrode moving direction.

[0016] Furthermore, the wrinkle-eliminating mechanism includes multiple parallel pressing rollers, the pressure of which is applied by an external drive mechanism, and the transmission belt is sequentially sleeved between the multiple pressing rollers and pulleys.

[0017] The lithium-ion battery electrode roll forming wrinkle elimination method based on the device described above includes releasing the lithium-ion battery electrode from the unwinding device and passing it sequentially through a wrinkle elimination mechanism and a roll forming device arranged opposite to each other.

[0018] When passing through the wrinkle-eliminating mechanism, the moving speed of the lithium-ion battery electrode is consistent with the linear speed of the pulley.

[0019] Compared with the prior art, the present invention has the following characteristics:

[0020] 1) This invention provides a lithium-ion battery electrode roll forming wrinkle elimination device, which tightly presses the transmission belt with the foil material in the blank area of ​​the electrode, preventing the foil material from cracking under high tension and enhancing the tensile and elongation properties of the foil material in the blank area. The portion of the transmission belt in contact with the blank area undergoes elastic deformation, creating a speed difference. Under the combined action of electrode tension, pressure roller pressure, and transmission belt friction, the blank area of ​​the electrode extends, and the extension direction is opposite to the electrode movement direction. This ensures that the extension amount of the coating area and the blank area of ​​the electrode remains consistent after roll forming, effectively preventing wrinkles and avoiding the frequent belt breakage problem caused by high-tension stretching.

[0021] 2) This invention provides a method for eliminating wrinkles during the rolling of lithium-ion electrodes. Utilizing a wrinkle-eliminating device, the elongation of the foil material in the blank area of ​​the electrode can be adjusted by changing multiple parameters such as the pressure of the pressing roller, the electrode tension, and the transmission belt tension. The number of wrinkle-eliminating devices can be increased or decreased depending on the different coating forms of the electrode, making it suitable for the rolling process of various types of lithium-ion electrodes. This solves the problems of wrinkles and belt breakage during rolling, improving the yield and production efficiency of electrode rolling.

[0022] 3) This invention utilizes a transmission belt to bond with the blank area of ​​the electrode sheet. Under the constraint of the elastic matrix, the foil is less prone to breakage, and its elongation is enhanced. At the same time, the transmission belt itself undergoes elastic deformation under tension, causing the foil in the blank area to stretch. Compared with rubber rollers, this design avoids the use of high tension, preventing the electrode sheet from tensile breaking and thus effectively avoiding the generation of roll-pressed wrinkles. Attached Figure Description

[0023] Figure 1 This is a three-dimensional structural schematic diagram of a lithium-ion battery electrode roll forming wrinkle elimination device according to the present invention;

[0024] Figure 2 This is a schematic diagram of the main structure of a lithium-ion battery electrode roll forming wrinkle elimination device according to the present invention;

[0025] Figure 3 This is a schematic diagram illustrating the working principle of a lithium-ion battery electrode roll forming wrinkle elimination device according to the present invention.

[0026] Figure 4 This is a schematic diagram of the roller-pressed wrinkle elimination device including two pressing rollers in the present invention;

[0027] Figure 5 This is a schematic diagram of the structure of a lithium-ion battery electrode rolling process device according to the present invention;

[0028] Explanation of markings in the diagram:

[0029] 1-Coating area, 2-Blank area, 3-Screw, 4-Fixing nut, 5-Mounting bracket, 6-Pressure roller, 7-Drive belt, 8-Pulley, 9-First drive device, 10-Second drive device, 11-Unwinding device, 12-Transition roller, 13-First tension cut-off roller pair, 14-First tension adjusting roller, 15-First tension detection roller, 16-First guide roller, 17-Second guide roller, 18-Second tension detection roller, 19-Second tension adjusting roller, 20-Second tension cut-off roller pair, 21-Third tension adjusting roller, 22-Third tension detection roller, 23-Third guide roller, 24-Lower pressure roller, 25-Upper pressure roller. Detailed Implementation

[0030] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The following embodiments are based on the above-described technical solutions of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0031] Example 1:

[0032] like Figure 1 , Figure 2 A lithium-ion battery electrode wrinkle removal device is shown, positioned after the unwinding device 11 and before the rolling mechanism. The rolling mechanism includes an upper pressure roller 25 and a lower pressure roller 24. The electrode has a coating area 1 in the middle and a blank area 2 at the edge. Two sets of wrinkle removal devices are arranged parallel to each other along the width of the electrode, corresponding to the blank areas on both sides of the electrode. The distance between the two sets is equal to the width of the coating area 1. Each set of wrinkle removal devices includes two wrinkle removal mechanisms symmetrically arranged vertically along the surface of the electrode. Each mechanism includes a pulley 8, a pressure roller 6, a transmission belt 7, a mounting bracket 5, an orientation adjustment mechanism, and first and second driving devices. The pulley 8 is driven by the first driving device, and its rotational linear velocity is consistent with the electrode's movement speed. The pressure roller 6 is passively driven by the transmission belt 7, or driven or resisted by the second driving device. The transmission belt 7 connects the pulley 8 and the pressure roller 6 and is tightly pressed against the blank area 2 of the electrode by the pressure roller 6. Figure 3As shown, the transmission belt 7 moves in the same direction as the electrode, and the linear velocity of the pulley 8 and the electrode are both V0. Due to the elastic deformation caused by the change in tension of the transmission belt, a speed difference occurs, so the linear velocity at point a on the transmission belt 7 is the lowest: V a =V0-ΔV, where ΔV is the elastic deformation caused by the change in belt tension. The portion of the transmission belt 7 pressed against the blank area of ​​the electrode plate: V b <V c <V d <V e =V0, meaning the linear velocity of the transmission belt 7 is lower than the linear velocity of the foil in the blank area. The transmission belt 7 generates a frictional force on the foil in the blank area that is opposite to the direction of electrode movement. Under the constraint of the transmission belt 7, the tensile and elongation capacity of the foil in the blank area of ​​the electrode is enhanced, thus effectively preventing cracking in the tab area caused by high tension. Under the combined action of the pressure of the clamping roller, the friction of the transmission belt, and the tension of the electrode, the blank area of ​​the electrode undergoes elongation deformation, ensuring that the elongation of the coating area 1 and the blank area 2 of the electrode remains consistent after roll forming, and avoiding roll forming wrinkles.

[0033] The pulley 8 is preferably made of aluminum alloy to reduce its weight, and its diameter is preferably 80mm. The pulley 8 can rotate around the axis of the pressure wheel, so that the blank area 2 of the electrode sheet and the transmission belt 7 are tightly pressed together at different positions on the pressure wheel 6.

[0034] The clamping wheel 6 is preferably made of steel, which has high strength and good wear resistance. The clamping wheel 6 is rotatably mounted on the mounting bracket 5, and the diameter of the clamping wheel 6 is preferably 100mm.

[0035] The transmission belt 7 is preferably a friction type transmission belt, and the material is preferably polyurethane rubber, which has good elasticity and wear resistance. The transmission belt 7 moves from the position of minimum tension to the position of maximum tension, that is, from... Figure 3 When point a moves to point e, its elastic elongation can reach up to 2%, and the width of the transmission belt 7 is the same as the width of the blank area 2 of the electrode plate.

[0036] The first and second drive devices are preferably driven by servo motors. The first drive device 9 provides active driving force to the pulley 8, and the linear speed of the pulley is consistent with the speed of the electrode plate. The second drive device 10 can provide driving force or resistance to the pressure wheel 6 to change the tension of the transmission belt 7.

[0037] The orientation adjustment mechanism preferably adjusts the up-and-down movement of the adjusting screw 3 and the fixing nut 4, and finely adjusts the deflection angle of the pressure wheel by adjusting the adjusting screw 3, so as to ensure that the transmission belt 7 and the electrode plate move in the same direction.

[0038] A method for eliminating wrinkles in lithium-ion battery electrode rolling based on the above-mentioned device, such as Figure 5As shown, the process includes releasing the lithium-ion battery electrode sheet from the unwinding device 11, and passing it successively through the transition roller 12, the first tension cut-off roller pair 13, the first tension adjusting roller 14, the first tension detection roller 15, the first guide roller 16, the symmetrically arranged wrinkle elimination mechanism, the second guide roller 17, the second tension detection roller 18, the second tension adjusting roller 19, the second tension cut-off roller pair 20, the third tension adjusting roller 21, the third tension detection roller 22, the third guide roller 23, and the rolling mechanism, and finally winding the electrode sheet through the winding device.

[0039] The specific steps include the following:

[0040] A. After the electrode is threaded, adjust screw 3 to change the height and deflection angle of the wrinkle elimination device to ensure that the transmission belt 7 of the upper and lower pressing rollers 6 is in contact with the foil material in the blank area of ​​the electrode, and that the speed direction of the transmission belt is consistent with the rolling direction.

[0041] B. The tension of the electrode sheet is controlled before and after the wrinkle elimination device and before and after the rolling mechanism by means of tension adjusting roller and tension detection roller;

[0042] C. The transmission belt 7 increases its speed under the driving force of the pulley 8, and the linear speed of the pulley is synchronized with the speed of the electrode.

[0043] D. Adjust the height of the wrinkle elimination device and adjust the clamping force between the upper and lower clamping rollers 6 and the blank area 2 of the electrode sheet;

[0044] E. Preferably, the second driving device 10 changes the driving force of the pressure wheel 6, adjusts the tension of the transmission belt, and thus adjusts the elastic deformation of the transmission belt and the speed difference between the transmission belt 7 and the electrode.

[0045] In step E, the tension before and after the wrinkle elimination device is adjusted so that the foil material in the electrode tab area is pre-extended by 1‰-10‰, so that the coating area 1 and the blank area 2 are extended in the same way after rolling, thereby completely avoiding the generation of wrinkles.

[0046] This lithium-ion battery electrode rolling wrinkle elimination device and method, designed in this way, allows the blank area 2 of the electrode to be pre-extended before rolling, ensuring that the extension amount of the coating area 1 and the blank area 2 is consistent after rolling, thus avoiding wrinkles. The blank area 2 and the transmission belt 7 are tightly pressed together by the pressure roller 6. Under the constraint of the transmission belt 7, the extensibility of the foil in the blank area is enhanced, preventing belt breakage under high tension.

[0047] Example 2:

[0048] A wrinkle-removing device for lithium-ion battery electrode roll forming is respectively arranged after the unwinding device 11 and before the rolling mechanism, and after the rolling mechanism and before the winding device. The rolling mechanism includes an upper pressure roller 25 and a lower pressure roller 24. The electrode has at least two coating areas 1, with a blank area 2 between the edge and the center coating areas 1. Multiple sets of wrinkle-removing devices are arranged parallel to each other along the width direction of the electrode, the number of which corresponds to the number of blank areas 2 of the electrode, and the distance between each set is equal to the width of the coating area 1. Each set of wrinkle-removing devices includes two components arranged symmetrically along the top and bottom of the electrode. Each component includes a pulley 8, a pressure roller 6, a drive belt 7, a mounting bracket 5, an orientation adjustment mechanism, and first and second drive devices. The pulley 8 is driven by the first drive device 9, and the rotational linear speed of the pulley 8 is consistent with the movement speed of the electrode. There are two pressure rollers 6, which are passively driven or driven or resisted by the second drive device 10. The transmission belt 7 connects the pulley 8 and the pressure wheel 6, and is tightly pressed against the blank area 2 of the electrode by the pressure wheel 6. For example... Figure 3 As shown, the transmission belt 7 moves in the same direction as the electrode, and the linear velocity of the pulley 8 and the electrode are both V0. Due to the elastic deformation caused by the tension change of the transmission belt 7, a velocity difference occurs, so the linear velocity at point a on the transmission belt 7 is the lowest: V a =V0-ΔV, where ΔV is the elastic deformation caused by the change in belt tension. The portion where the belt 7 is pressed against the blank area 2 of the electrode plate: V b <V c <V d <V e =V0, meaning the linear speed of the transmission belt 7 is lower than the linear speed of the foil in the blank area. The transmission belt 7 generates a frictional force on the foil in the blank area that is opposite to the direction of electrode movement. Under the constraint of the transmission belt 7, the tensile and elongation capacity of the foil in the blank area of ​​the electrode is enhanced, avoiding the electrode tab cracking phenomenon caused by high tension. The blank area 2 of the electrode extends under the combined action of the pressure of the clamping roller, the friction of the transmission belt, and the electrode tension, ensuring that the extension amount of the electrode coating area 1 and the blank area 2 is consistent after roll forming, avoiding roll forming wrinkles.

[0049] The pulley 8 is preferably made of aluminum alloy to reduce its weight, and the pulley diameter is preferably 80mm.

[0050] The clamping roller 6 is preferably made of steel, which has high strength and good wear resistance. The clamping roller 6 has an active drive device or is passively driven by a transmission belt 7. The clamping roller 6 is rotatably mounted on the mounting bracket 5, and the diameter of the clamping roller 6 is preferably 80mm.

[0051] The transmission belt 7 is preferably a friction type transmission belt, and the material is preferably polyurethane rubber, which has good elasticity and wear resistance. The transmission belt 7 moves from the position of minimum tension to the position of maximum tension, that is, from... Figure 3When point a moves to point e, its elastic elongation can reach up to 2%, and the width of the transmission belt 7 is consistent with the width of the blank area 2 of the electrode plate.

[0052] The first and second drive devices are preferably driven by servo motors. The first drive device 9 provides active driving force to the pulley 8, and the linear speed of the pulley is consistent with the speed of the electrode plate. The second drive device 10 can provide driving force or resistance to the pressure wheel 6 to change the tension of the transmission belt 7.

[0053] The orientation adjustment mechanism preferably adjusts the up-and-down movement of the adjusting screw 3 and the fixing nut 4, and finely adjusts the deflection angle of the pressure wheel 6 by adjusting the adjusting screw 3, so as to ensure that the transmission belt 7 moves in the same direction as the electrode.

[0054] The lithium-ion battery electrode roll forming wrinkle elimination device described above has the following operating steps:

[0055] A. After the electrode is threaded, adjust screw 3 to change the height and deflection angle of the wrinkle elimination device to ensure that the transmission belt 7 of the upper and lower pressing rollers 6 is in contact with the foil material in the blank area of ​​the electrode, and that the speed direction of the transmission belt is consistent with the rolling direction.

[0056] B. The tension of the electrode sheet is controlled before and after the wrinkle elimination device and before and after the rolling mechanism by means of tension adjusting roller and tension detection roller;

[0057] C. The transmission belt 7 increases its speed under the driving force of the pulley 8, so that the linear speed of the pulley is synchronized with the speed of the electrode.

[0058] D. Adjust the rotation angle of pulley 8 around the axis of pressure wheel 6 so that the blank area 2 of the electrode sheet and the transmission belt 7 are tightly pressed together at different positions on the pressure wheel 6;

[0059] E. Adjust the height of the wrinkle elimination device and adjust the clamping force between the upper and lower clamping rollers 6 and the blank area 2 of the electrode sheet;

[0060] F. By changing the driving force of the pressure wheel 6 through the second driving device 10, the tension of the transmission belt is adjusted, thereby adjusting the elastic deformation of the transmission belt and the speed difference between the transmission belt 7 and the electrode.

[0061] In step F, based on the severity of wrinkles in the blank area of ​​the electrode after rolling, the tension before and after the wrinkle elimination device, the clamping force between the pressure roller 6 and the blank area, and the tension of the transmission belt 7 are adjusted again. First, the blank area 2 of the electrode is pre-extended by a certain amount before rolling. After rolling, the electrode passes through the wrinkle elimination device again, causing the blank area 2 to extend by a certain amount again until the coating area 1 and the blank area 2 are extended to the same extent after rolling, thus completely avoiding the generation of wrinkles.

[0062] This lithium-ion battery electrode rolling wrinkle elimination device, or method, is designed to ensure that the blank area of ​​the electrode generates a certain amount of extension before and after rolling, guaranteeing that the extension of the coating area 1 and the blank area 2 remains consistent after rolling, thus preventing wrinkles. The wrinkle elimination device can increase or decrease the number of parallel sets according to different electrode coating methods, and can also change the width of the transmission belt according to different blank area 2 widths, making it suitable for rolling processes of various types of lithium-ion battery electrodes.

[0063] Example 3:

[0064] A lithium-ion battery electrode rolling wrinkle elimination device is used to fully extend the blank area 2 on the lithium-ion battery electrode so that wrinkles do not appear when it is rolled together with the coating area 1. The device includes a wrinkle elimination mechanism that is relatively pressed between the two sides of the wrinkle-prone area of ​​the electrode. The wrinkle elimination mechanism includes a pressure wheel 6, a pulley 8, and a transmission belt 7 sleeved between the pressure wheel 6 and the pulley 8. The pulley 8 serves as a drive wheel and is located in front of the pressure wheel 6 along the electrode movement direction. The transmission belt 7 is pressed against the wrinkle-prone area of ​​the electrode by the pressure wheel 6, that is, the transmission belt 7 is tightly pressed against the foil surface of the blank area of ​​the electrode, which enhances the tensile and elongation properties of the blank area of ​​the electrode and prevents the foil from cracking. At the same time, the tension of the transmission belt on the side closer to the electrode is greater than that on the side farther from the electrode. Due to the tension change, the transmission belt 7 undergoes elastic deformation and speed difference, and under the combined action of friction, pressure, and tension, the foil is stretched. By changing the driving force of pulley 8 and pressure wheel 6, the tension of the transmission belt can be changed, which in turn changes the elastic deformation of the transmission belt 7, causing the foil material in the blank area to undergo different degrees of extension and deformation.

[0065] In some specific embodiments, the transmission belt 7 is closely fitted to the blank area of ​​the electrode sheet to prevent the foil from cracking and enhance its ductility, and the width of the transmission belt 7 does not exceed the width of the blank area.

[0066] In some specific embodiments, the pulley 8 is driven and connected to the first drive device 9.

[0067] In some specific embodiments, the pressing wheel 6 can be actively driven or passively driven. That is, the pressing wheel 6 can be a driven wheel, following the pulley 8 to rotate via the transmission belt 7. When the pressing wheel 6 rotates, the tension of the transmission belt 7 changes continuously, producing elastic deformation. At the same time, it can also be connected to the second driving device 10, which controls the rotational linear speed relative to the pulley 8 to regulate the tension of the pressing side transmission belt 7, thereby controlling the interaction effect between the transmission belt 7 and the foil blank area.

[0068] In some specific embodiments, the number of pressure rollers 6 is one or more. When the pressure rollers 6 rotate, the tension of the transmission belt 7 changes continuously, resulting in elastic deformation. Preferably, as... Figure 4As shown, multiple clamping wheels 6 can be arranged in parallel, and the transmission belt 7 is sequentially sleeved between the multiple clamping wheels 6 and the pulley 8.

[0069] In some specific embodiments, both the first driving device 9 and the second driving device 10 include a drive motor.

[0070] In some specific embodiments, the transmission belt 7 has good elasticity and wear resistance, and the material of the transmission belt 7 is polyurethane or other rubber or other polymers or composite materials.

[0071] In some specific embodiments, a base is also included, and the wrinkle elimination mechanism further includes a mounting bracket 5, with a pressure wheel 6 and a pulley 8 mounted on the mounting bracket 5. A screw 3 is provided on the base perpendicular to the electrode plate, and the mounting bracket 5 has a clearance hole for the screw 3 to pass through, with a fixing nut 4 threadedly connected to the screw 3 in the clearance hole.

[0072] In some specific embodiments, such as Figure 5 As shown, it also includes a transition roller 12, a first tension cut-off roller pair 13, a first tension adjusting roller 14, a first tension detecting roller 15, and a first guide roller 16 arranged sequentially between the unwinding device 11 and the wrinkle elimination mechanism along the electrode moving direction, and a second guide roller 17, a second tension detecting roller 18, a second tension adjusting roller 19, a second tension cut-off roller pair 20, a third tension adjusting roller 21, a third tension detecting roller 22, and a third guide roller 23 arranged sequentially between the wrinkle elimination mechanism and the rolling mechanism along the electrode moving direction.

[0073] A method for eliminating wrinkles in lithium-ion battery electrode sheets by rolling includes releasing the lithium-ion battery electrode sheet from an unwinding device 11, and passing it sequentially through a transition roller 12, a first tension cutoff roller pair 13, a first tension adjusting roller 14, a first tension detection roller 15, a first guide roller 16, a symmetrically arranged wrinkle elimination mechanism, a second guide roller 17, a second tension detection roller 18, a second tension adjusting roller 19, a second tension cutoff roller pair 20, a third tension adjusting roller 21, a third tension detection roller 22, a third guide roller 23, and a rolling mechanism, finally winding the electrode sheet through a rewinding device; wherein, the unwinding device 11 is used to unwind the electrode sheet, the rolling mechanism includes an upper pressure roller 25 and a lower pressure roller 24 and is used to roll the electrode sheet, and the tension adjusting roller is used to adjust the electrode sheet tension before and after the wrinkle elimination device and the electrode sheet rolling mechanism; specifically, the method includes the following steps:

[0074] S1: After the electrode is threaded, adjust the height and deflection angle of the wrinkle elimination mechanism to ensure that the transmission belt 7 of the upper and lower pressing rollers 6 is in contact with the foil material in the blank area of ​​the electrode, and that the speed direction of the transmission belt is consistent with the rolling direction.

[0075] S2: The tension of the electrode sheet is controlled before and after the wrinkle elimination mechanism and the rolling mechanism by means of the tension adjustment roller and the tension detection roller;

[0076] S3: The transmission belt 7 increases its speed under the drive of the pulley 8, so that the linear speed of the pulley 8 is synchronized with the speed of the electrode.

[0077] S4: Adjust the height of the wrinkle elimination mechanism and adjust the clamping force between the upper and lower clamping rollers 6 and the blank area of ​​the electrode sheet;

[0078] S5: When necessary, the driving force of the pressure wheel 6 is changed by the second drive device 10, the tension of the transmission belt 7 is adjusted, and the elastic deformation of the transmission belt 7 and the speed difference between the transmission belt and the electrode are adjusted.

[0079] In some specific embodiments, the wrinkle elimination device may be provided individually or simultaneously between the unwinding device and the rolling device, or between the rolling device and the winding device.

[0080] In some specific embodiments, multiple sets of wrinkle elimination devices can be arranged parallel to each other along the width direction of the electrode, the number of which corresponds to the number of blank areas 2 of the electrode, and the interval between each set is equal to the width of the coating area 1.

[0081] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method for eliminating wrinkles in the rolling of lithium-ion battery electrode sheets, wherein a wrinkle elimination device for the rolling of lithium-ion battery electrode sheets is disposed between an unwinding device (11) and a rolling mechanism, the wrinkle elimination device comprising wrinkle elimination mechanisms disposed on both sides of the wrinkle-prone area of ​​the electrode sheet, the wrinkle elimination mechanisms comprising a pressing wheel (6), a pulley (8), and a transmission belt (7) sleeved between the pressing wheel (6) and the pulley (8); the pulley (8) is driven to a first driving device (9), and the pressing wheel (6) is driven to a second driving device (10). The transmission belt (7) is pressed against the area where the electrode wrinkles are prone to occur by the pressure wheel (6) and undergoes elastic deformation; the pulley (8) serves as the drive wheel and is located in front of the pressure wheel (6) along the direction of electrode movement; its characteristic is that, The lithium-ion battery electrode is released from the unwinding device (11) and passes through the wrinkle elimination mechanism and the rolling mechanism arranged opposite to each other. When passing through the wrinkle elimination mechanism, the moving speed of the lithium-ion battery electrode is consistent with the linear speed of the pulley (8); By changing the driving force of the pressure wheel (6) through the second drive device (10), the tension of the transmission belt is adjusted, thereby adjusting the elastic deformation of the transmission belt and the speed difference between the transmission belt (7) and the electrode.

2. The method according to claim 1, wherein the method is characterized by, The transmission belt (7) is a rubber transmission belt.

3. The method for eliminating wrinkles in the rolling of lithium-ion battery electrode sheets according to claim 2, characterized in that, The transmission belt (7) is a polyurethane transmission belt.

4. The method for eliminating wrinkles in the rolling of lithium-ion battery electrode sheets according to claim 1, characterized in that, Both the first driving device (9) and the second driving device (10) include a drive motor.

5. The method for eliminating wrinkles in the rolling of lithium-ion battery electrode sheets according to claim 1, characterized in that, The wrinkle elimination mechanism also includes a mounting bracket (5), and the pressure wheel (6) and pulley (8) are mounted on the mounting bracket (5).

6. The method for eliminating wrinkles in the rolling of lithium-ion battery electrode sheets according to claim 5, characterized in that, The roll forming wrinkle elimination device also includes a base, on which a screw (3) is provided perpendicular to the electrode plate. The mounting bracket (5) is provided with a clearance hole for the screw (3) to pass through, and a fixing nut (4) is provided on the clearance hole to be threadedly connected to the screw (3).

7. The method for eliminating wrinkles in the rolling of lithium-ion battery electrode sheets according to claim 1, characterized in that, The roll forming wrinkle elimination device further includes a transition roller (12), a first tension cut-off roller pair (13), a first tension adjusting roller (14), a first tension detection roller (15), and a first guide roller (16) arranged sequentially between the unwinding device (11) and the wrinkle elimination mechanism along the electrode moving direction, and a second guide roller (17), a second tension detection roller (18), a second tension adjusting roller (19), a second tension cut-off roller pair (20), a third tension adjusting roller (21), a third tension detection roller (22), and a third guide roller (23) arranged sequentially between the wrinkle elimination mechanism and the roll forming mechanism along the electrode moving direction.

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