Cell winding method and cell winding system

Abstract

Provided in the present application are a cell winding method and a cell winding system. The cell winding method comprises: material incoming, winding starting, embossing, and winding, wherein material incoming is used for acquiring a separator, a cathode electrode sheet and an anode electrode sheet, and the cathode electrode sheet obtained from material incoming satisfies: after pre-winding is completed, a first cathode tab and a second cathode tab, which are arranged adjacent to each other, at the position of the cathode sheet that is close to a winding end form a surplus misalignment; winding starting is used for fixing starting ends of the separator, the cathode electrode sheet and the anode electrode sheet to a winding apparatus; embossing is used for embossing the cathode electrode sheet by means of a rolling apparatus, such that the cathode electrode sheet subjected to an embossing treatment satisfies: after winding is completed, the first cathode tab is aligned with the second cathode tab; and winding is used for winding the separator, the cathode electrode sheet and the anode electrode sheet by means of the winding apparatus.

Description

Battery cell winding method and battery cell winding system

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on June 29, 2023, with priority number 2023107878463 and application name “Battery Cell Winding Method and Battery Cell Winding System”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application belongs to the field of battery cell winding technology, and in particular relates to a battery cell winding method and a battery cell winding system. Background Art

[0003] The alignment of the tabs on a battery cell affects the electrical performance of the finished battery. For example, the misalignment of the cathode tab is typically controlled during the manufacturing process as an indicator of tab misalignment. However, during the winding process, due to variations in electrode thickness, tab misalignment can occur as the number of winding turns increases, impacting the cell's yield rate.

[0004] The existing technology improves the phenomenon of tab misalignment by obtaining and calculating the misalignment of the tabs in multiple battery cells with historical winding, and then fixedly adjusting the relevant parameters of the embossing process. However, obtaining and calculating the misalignment of the tabs in multiple battery cells with historical winding requires processing a lot of data. Moreover, since the thickness and position of the incoming electrode are uncertain, improving the tab misalignment phenomenon by simply adjusting the relevant parameters of the embossing process by analyzing historical data can easily cause the thicker part of the electrode to be thicker than the thinner part, which will increase the misalignment of the tabs after the battery cell is wound, and thus lead to a decrease in the winding yield of the battery cell.

[0005] Therefore, how to design a battery cell winding method and battery cell winding system to reduce the amount of tab misalignment and thereby improve the battery cell winding yield has become a technical problem that needs to be solved urgently.

[0006] Summary of the Invention

[0007] In order to address the shortcomings of the existing technology, the present application provides a method and system for winding a battery cell, which can reduce the misalignment of the tabs and thereby improve the winding yield of the battery cell.

[0008] In one aspect, the present application provides a method for winding a battery cell, comprising:

[0009] Incoming materials are used to obtain a separator, a cathode electrode piece, and an anode electrode piece; the incoming cathode electrode piece satisfies the following conditions: after pre-winding, a first cathode electrode tab and a second cathode electrode tab adjacent to each other near a winding end of the cathode electrode piece form a surplus misalignment;

[0010] Rolling up, fixing the starting ends of the diaphragm, the cathode electrode piece and the anode electrode piece on a winding device;

[0011] Embossing, embossing the cathode electrode sheet through a roller pressing device so that the cathode electrode sheet after embossing satisfies: after winding, the first cathode electrode tab is aligned with the second cathode electrode tab; and

[0012] Winding: Winding the separator, the cathode plate and the anode plate through the winding device.

[0013] The present application provides a method for winding a battery cell. First, in the material receiving step, the cathode electrode sheet is configured so that after the pre-winding is completed, the first cathode electrode ear and the second cathode electrode ear adjacent to each other near the winding end of the cathode electrode sheet form a surplus misalignment, that is, the distance between the first cathode electrode ear and the second cathode electrode ear on the cathode electrode sheet in the unfolded state is increased in advance. Then, in the embossing step, the cathode electrode sheet is embossed to thicken the cathode electrode sheet. When the battery cell is wound, the cathode electrode sheet is thickened, so that the first cathode electrode ear and the second cathode electrode ear that were originally surplus misaligned are aligned. Moreover, by fixing the rolling parameters of the rolling device, the overall thickness of the cathode electrode sheet can be made more uniform, so that the electrodes on the cathode electrode sheet that are different from the first cathode electrode ear and the second cathode electrode ear can be aligned. Therefore, the winding method provided by this embodiment can reduce the amount of electrode ear misalignment, thereby improving the yield rate of battery cell winding.

[0014] On the other hand, the present application also provides a battery cell winding system, comprising:

[0015] A feeding device is used to provide a separator, a cathode electrode piece and an anode electrode piece; the incoming cathode electrode piece satisfies: after winding, a first cathode electrode tab and a second cathode electrode tab adjacent to each other near the winding end of the cathode electrode piece form a surplus misalignment;

[0016] A rolling device for embossing the cathode electrode sheet so that the embossed cathode electrode sheet satisfies the following conditions: after winding, the first cathode electrode tab is aligned with the second cathode electrode tab; and

[0017] The winding device is used to fix the starting ends of the diaphragm, the cathode electrode piece and the anode electrode piece, and to wind the diaphragm, the cathode electrode piece and the anode electrode piece.

[0018] The battery cell winding system provided by the embodiment of the present application, first, by designing the cathode electrode sheet provided by the feeding device, so that the cathode electrode sheet is configured as follows: after the pre-winding is completed, the first cathode electrode ear and the second cathode electrode ear adjacent to each other near the winding end of the cathode electrode sheet form a surplus misalignment, that is, the distance between the first cathode electrode ear and the second cathode electrode ear on the cathode electrode sheet in the unfolded state is increased in advance. Then, the starting end of the diaphragm, cathode electrode sheet and anode electrode sheet provided by the feeding device is fixed by the winding device, and the cathode electrode sheet is embossed by the rolling device to thicken the cathode electrode sheet. Finally, the diaphragm, cathode electrode sheet and anode electrode sheet are wound by the winding device. When the battery cell is wound, the cathode electrode sheet is thickened, so that the first cathode electrode ear and the second cathode electrode ear that were originally surplus misaligned are aligned. Moreover, by fixing the rolling parameters of the rolling device, the overall thickness of the cathode electrode sheet can be made more uniform, so that the electrodes on the cathode electrode sheet that are different from the first cathode electrode ear and the second cathode electrode ear can be aligned. Therefore, the battery cell winding system provided in this embodiment can reduce the amount of tab misalignment, thereby improving the yield of battery cell winding. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] To more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some implementation methods provided by the embodiments of the present application. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0020] FIG1 is a schematic flow chart of a method for winding a battery cell according to an embodiment of the present application;

[0021] FIG2 is a schematic diagram of a wound battery cell provided by one embodiment of the present application;

[0022] FIG3 is a schematic diagram of a battery cell winding system provided in one embodiment of the present application;

[0023] FIG4 is a schematic diagram of a cathode electrode provided in an expanded state according to an embodiment of the present application;

[0024] FIG5 is a schematic diagram of a rolling device provided in one embodiment of the present application;

[0025] FIG6 is a schematic flow chart of a battery cell winding method provided in another embodiment of the present application;

[0026] FIG7 is a schematic diagram of winding a cathode electrode in an ideal state provided by an embodiment of the present application;

[0027] FIG8 is a schematic diagram of winding a cathode electrode in the case of surplus misalignment provided by an embodiment of the present application;

[0028] FIG9 is a schematic diagram of a cathode electrode sheet wound after embossing according to an embodiment of the present application;

[0029] FIG10 is a flow chart of determining embossing pressure according to an embodiment of the present application;

[0030] FIG11 is a diagram showing the corresponding relationship between embossing depth and embossing pressure provided in one embodiment of the present application;

[0031] FIG12 is a schematic diagram of a process for determining the spacing between other cathode tabs on a cathode electrode sheet that are different from the first cathode tab and the second cathode tab, provided in one embodiment of the present application;

[0032] FIG13 is a schematic diagram of a process for determining the distance between a first cathode tab and a second cathode tab on a cathode electrode sheet according to an embodiment of the present application;

[0033] FIG14 is a diagram showing the corresponding relationship between the misalignment amount of the cathode tab and the embossing pressure according to an embodiment of the present application;

[0034] FIG15 is a schematic diagram of a process for determining the spacing between other cathode tabs on a cathode electrode sheet, different from the first cathode tab and the second cathode tab, provided by another embodiment of the present application;

[0035] FIG16 is a schematic diagram of a process for determining the distance between a first cathode tab and a second cathode tab on a cathode electrode sheet according to another embodiment of the present application;

[0036] FIG17 is a diagram showing the corresponding relationship between the misalignment amount of the anode tab and the embossing pressure according to an embodiment of the present application;

[0037] FIG18 is a schematic diagram of a process for determining the spacing between other cathode tabs on a cathode electrode sheet that are different from the first cathode tab and the second cathode tab, provided by another embodiment of the present application. DETAILED DESCRIPTION

[0038] The technical solution of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0039] The existing technology obtains the relevant parameters of the tab misalignment of the wound battery cell during the winding process, and controls the embossing pressure change through the aforementioned tab misalignment parameters to change the thickness of the electrode sheet, thereby reducing the amount of tab misalignment during the current battery cell winding process to improve the battery cell yield rate. However, the process of obtaining the relevant parameters of the tab misalignment of the wound battery cell during the winding process requires obtaining relevant data of a large amount of wound battery cells, which makes the battery cell winding process more cumbersome. Moreover, since the thickness and position of the incoming electrode sheet are uncertain, only referring to the relevant parameters of the tab misalignment of the wound battery cell during the winding process to change the embossing pressure in the embossing design can easily cause the thin parts of the electrode sheet to be thinner and the thick parts to be thicker, which in turn increases the amount of tab misalignment of the battery cell, and still leads to a low battery cell yield rate.

[0040] Based on this, the present application provides a method and system for winding a battery cell to reduce the amount of tab misalignment and thereby improve the battery cell winding yield.

[0041] Please refer to Figures 1, 2 and 3. Figure 1 is a flow chart of a method for winding a battery cell provided in an embodiment of the present application. Figure 2 is a schematic diagram of a battery cell after winding provided in an embodiment of the present application. Figure 3 is a schematic diagram of a battery cell winding system provided in an embodiment of the present application. Figure 4 is a schematic diagram of a cathode electrode in an unfolded state provided in an embodiment of the present application.

[0042] An embodiment of the present application provides a method for winding a battery cell to improve tab misalignment. The method comprises the following steps:

[0043] S11: Material receiving step. This step is used to obtain the separator 1, cathode electrode sheet 3, and anode electrode sheet 5. Furthermore, the cathode electrode sheet 3 obtained in this step is configured such that, after the pre-winding of the battery cell 10 is completed, the first cathode electrode tab 31 and the second cathode electrode tab 32 adjacent to each other near the winding end of the cathode electrode sheet 3 form a surplus misalignment.

[0044] S12 : Rolling step. The rolling step is used to fix the starting end of the separator 1 , the starting end of the cathode electrode piece 3 , and the starting end of the anode electrode piece 5 on the winding device 40 .

[0045] S13: Embossing step. The embossing step is to emboss the cathode electrode sheet 3 through the roller pressing device 60, and configure the cathode electrode sheet 3 after the embossing process so that the first cathode tab 31 and the second cathode tab 32 are aligned after the battery cell 10 is wound.

[0046] S14: Winding step. The winding step is used to wind the separator 1 , the cathode electrode sheet 3 and the anode electrode sheet 5 through the winding device 40 to form the battery cell 10 .

[0047] The pre-winding of the battery cell 10 is performed before the cathode electrode 3 is embossed, in order to facilitate the measurement and calculation of parameters related to the surplus misalignment between the first cathode tab 31 and the second cathode tab 32 .

[0048] The battery cell winding method provided in this embodiment first arranges the cathode electrode sheet 3 in the incoming material step so that, after the pre-winding of the battery cell 10 is completed, the first cathode tab 31 and the second cathode tab 32 adjacent to each other near the winding end of the cathode electrode sheet 3 are offset. This means that the spacing between the first cathode tab 31 and the second cathode tab 32 on the cathode electrode sheet 3 when in the unfolded state is preliminarily increased. Then, in the embossing step, the cathode electrode sheet 3 is embossed to increase its thickness. After the battery cell 10 is wound, the increased thickness of the cathode electrode sheet 3 aligns the previously offset first and second cathode tabs 31 and 32. Furthermore, by fixing the rolling parameters of the rolling device 60, the overall thickness of the cathode electrode sheet 3 can be made more uniform, ensuring alignment of the tabs on the cathode electrode sheet 3 other than the first and second cathode tabs 31 and 32. Thus, the battery cell winding method provided in this embodiment can reduce tab offset, thereby improving the winding yield of the battery cell 10.

[0049] It should be understood that the separator 1 provided in this embodiment includes a first separator 11 and a second separator 12. Before the electrode sheets of the battery cell 10 are wound, the first separator 11, the cathode electrode sheet 3, the second separator 12, and the anode electrode sheet 5 are stacked in sequence. After the electrode sheets of the battery cell 10 are wound, the first separator 11, the cathode electrode sheet 3, the second separator 12, and the anode electrode sheet 5 are stacked in sequence from the inside to the outside.

[0050] Based on the above method, this embodiment provides a battery cell winding system 100, including a feeding device 20, a winding device 40 and a rolling device 60. The feeding device 20 is used to provide a diaphragm 1, a cathode electrode sheet 3 and an anode electrode sheet 5. The cathode electrode sheet 3 provided by the feeding device 20 is configured so that after the pre-winding is completed, the first cathode electrode sheet 31 and the second cathode electrode sheet 32 ​​adjacent to each other near the winding end of the cathode electrode sheet 3 form a surplus misalignment. The rolling device 60 is used to emboss the cathode electrode sheet 3 so that the cathode electrode sheet 3 after the embossing is configured so that after the winding is completed, the first cathode electrode sheet 31 and the second cathode electrode sheet 32 ​​are aligned. The winding device 40 is used to fix the starting ends of the diaphragm 1, the cathode electrode sheet 3 and the anode electrode sheet 5, and to wind the diaphragm 1, the cathode electrode sheet 3 and the anode electrode sheet 5.

[0051] The battery cell winding system 100 provided in the embodiment of the present application, first, by designing the cathode electrode sheet 3 provided by the feeding device 20, so that the cathode electrode sheet 3 is configured as follows: after the pre-winding is completed, the first cathode electrode ear 31 and the second cathode electrode ear 32 adjacent to each other near the winding end of the cathode electrode sheet 3 form a surplus misalignment, that is, the distance between the first cathode electrode ear 31 and the second cathode electrode ear 32 on the cathode electrode sheet 3 in the unfolded state is increased in advance. Then, the starting ends of the diaphragm 1, cathode electrode sheet 3 and anode electrode sheet 5 provided by the feeding device 20 are fixed by the winding device 40, and the cathode electrode sheet 3 is embossed by the rolling device 60 to thicken the cathode electrode sheet 3. Finally, the diaphragm 1, cathode electrode sheet 3 and anode electrode sheet 5 are wound by the winding device 40. After the winding is completed, due to the thickening of the cathode electrode sheet 3, the first cathode electrode ear 31 and the second cathode electrode ear 32 that were originally surplus misaligned are aligned. Furthermore, by fixing the rolling parameters of the rolling device 60, the overall thickness of the cathode electrode sheet 3 can be made more uniform, so that the tabs on the cathode electrode sheet 3 that are different from the first cathode tab 31 and the second cathode tab 32 can be aligned. Thus, the battery cell winding system 100 provided in this embodiment can reduce the amount of tab misalignment, thereby improving the yield rate of battery cell winding.

[0052] Please refer to FIG. 3 and FIG. 5 . FIG. 5 is a schematic diagram of a rolling device provided in an embodiment of the present application.

[0053] Specifically, the rolling device 60 includes a bracket 61, a first pressing roller 62, a first driving member 63, a second pressing roller 64, a second driving member 65, and a control valve 66. The first pressing roller 62 is rotatably mounted on the bracket 61. The first driving member 63 is used to drive the first pressing roller 62 to rotate. The second pressing roller 64 is rotatably mounted on the bracket 61 and is arranged parallel to the first pressing roller 62. The second driving member 65 is used to drive the first pressing roller 62 toward or away from the second pressing roller 64 to adjust the embossing pressure of the rolling device 60. The control valve 66 is electrically connected to the second driving member 65 to control the distance that the second driving member 65 drives the first pressing roller 62 to move toward or away from the second pressing roller 64.

[0054] The battery cell winding system 100 provided in this embodiment controls the movement or fixation of the second driving member 65 by adjusting the control valve 66, thereby driving the first pressing roller 62 to move toward or away from the second pressing roller 64 or to be relatively fixed, so as to adjust or fix the embossing pressure provided by the rolling device 60 to the cathode electrode 3, thereby enabling the rolling device 60 to be applied to cathode electrodes 3 requiring different embossing depths.

[0055] More specifically, in this embodiment, the first pressing roller 62 is a rubber-coated roller, the first driving member 63 is a motor, the second pressing roller 64 is an embossing roller, the second driving member 65 is a cylinder, and the control valve 66 is a proportional valve.

[0056] In this embodiment, the first pressure roller 62 meets the following requirements: the first pressure roller 62 rotates actively, the material of the first pressure roller 62 is composed of ordinary aluminum roller and polyurethane, the hardness of the first pressure roller 62 is 35HS, the diameter of the first pressure roller 62 is 29.6 mm, and the length of the first pressure roller 62 is 213 mm.

[0057] In this embodiment, the second pressure roller 64 meets the following requirements: the second pressure roller 64 rotates passively, the material of the second pressure roller 64 is high-strength aluminum alloy, the hardness of the second pressure roller 64 is 500HV, the diameter of the second pressure roller 64 is 29.6 mm, the length of the second pressure roller 64 is 213 mm, the raised points on the second pressure roller 64 are circular, the radius of the raised points on the second pressure roller 64 is 3.6 mm, the center distance between two adjacent raised points on the second pressure roller 64 is 3.5 mm, the raised height of the raised points on the second pressure roller 64 is 0.8 mm, and the parallelism between the second pressure roller 64 and the first pressure roller 62 is 0.03 mm.

[0058] In this embodiment, the control valve 66 controls the proportional solenoid by outputting proportional current through pulses. The proportional solenoid proportionally controls the position of the valve core to achieve rapid pressure increase and decrease regulation. The control accuracy of the control valve 66 is limited to or equal to ±0.002Mpa.

[0059] It is understandable that in other embodiments, the first driving member 63 and the second driving member 65 can be other driving structures, the first pressure roller 62 and the second pressure roller 64 can be other roller structures, and the control valve 66 can be other control devices. This application does not impose any restrictions on this.

[0060] Please refer to FIG6 , which is a schematic flow chart of a battery cell winding method provided in another embodiment of the present application.

[0061] An embodiment of the present application provides a method for winding a battery cell to improve tab misalignment. The method comprises the following steps:

[0062] S21: Material receiving step. This step is used to obtain the separator 1, cathode electrode sheet 3, and anode electrode sheet 5. Furthermore, the cathode electrode sheet 3 obtained in this step is configured such that, after the pre-winding of the battery cell 10 is completed, the first cathode electrode tab 31 and the second cathode electrode tab 32 adjacent to each other near the winding end of the cathode electrode sheet 3 form a surplus misalignment.

[0063] S22 : Rolling step. The rolling step is used to fix the starting end of the separator 1 , the starting end of the cathode electrode piece 3 , and the starting end of the anode electrode piece 5 on the winding device 40 .

[0064] S23: Embossing step. The embossing step is used to emboss the separator 1 and the cathode electrode 3 through the roller pressing device 60, and the cathode electrode 3 after the embossing is configured so that the first cathode tab 31 and the second cathode tab 32 are aligned after the battery cell 10 is wound.

[0065] S24 : Winding step. The winding step is used to wind the separator 1 , the cathode electrode sheet 3 and the anode electrode sheet 5 through the winding device 40 to form the battery cell 10 .

[0066] The method for winding a battery cell provided in this embodiment is as follows: first, in the incoming material step, the cathode electrode sheet 3 is configured so that after the battery cell 10 is pre-wound, the first cathode electrode tab 31 and the second cathode electrode tab 32 adjacently arranged near the winding end of the cathode electrode sheet 3 form a surplus misalignment, that is, the distance between the first cathode electrode tab 31 and the second cathode electrode tab 32 on the cathode electrode sheet 3 in the unfolded state is pre-increased. Then, in the embossing step, the separator 1 and the cathode electrode sheet 3 are embossed to thicken the separator 1 and the cathode electrode sheet 3. After the battery cell 10 is wound, the separator 1 and the cathode electrode sheet 3 are thickened, so that the first cathode electrode tab 31 and the second cathode electrode tab 32 that were originally surplus misaligned are aligned. Moreover, by fixing the rolling parameters of the rolling device 60, the overall thickness of the separator 1 and the cathode electrode sheet 3 can be made more uniform, so that the other electrodes on the cathode electrode sheet 3 other than the first cathode electrode tab 31 and the second cathode electrode tab 32 can be aligned. Therefore, the battery cell winding method provided in this embodiment can reduce the amount of tab misalignment, thereby improving the winding yield of the battery cell 10.

[0067] In one specific embodiment, the embossing step is used to perform embossing on the first separator 11 and the cathode electrode piece 3 so as to thicken the first separator 11 and the cathode electrode piece 3. In another specific embodiment, the embossing step is used to perform embossing on the second separator 12 and the cathode electrode piece 3 so as to thicken the second separator 12 and the cathode electrode piece 3. In yet another specific embodiment, the embossing step is used to perform embossing on the first separator 11, the second separator 12 and the cathode electrode piece 3 so as to thicken the first separator 11, the second separator 12 and the cathode electrode piece 3. It is understandable that in some other embodiments, the embossing step in the winding method of the battery cell is used to perform embossing on the separator 1, the cathode electrode piece 3 and the anode electrode piece 5 through the rolling device 60, and the cathode electrode piece 3 that has been embossed is configured so that after the battery cell 10 is wound, the first cathode tab 31 is aligned with the second cathode tab 32.

[0068] Please refer to Figures 7, 8 and 9. Figure 7 is a schematic diagram of the winding of a cathode electrode provided in an ideal state according to an embodiment of the present application. Figure 8 is a schematic diagram of the winding of a cathode electrode provided in an embodiment of the present application when there is surplus misalignment. Figure 9 is a schematic diagram of the winding of a cathode electrode provided in an embodiment of the present application after embossing treatment.

[0069] Specifically, the surplus misalignment between the first cathode tab 31 and the second cathode tab 32 satisfies the following conditions: after the pre-winding of the cathode electrode sheet 3 is completed, the first cathode tab 31 is located within the first coil, and the second cathode tab 32 is located within the second coil. The second cathode tab 32 has a surplus amount ΔL relative to the first cathode tab 31. The surplus amount ΔL is the distance from the geometric center of the first cathode tab 31 to the geometric center of the second cathode tab 32 along the winding path of the cathode electrode sheet 3.

[0070] In the battery cell winding method provided in this embodiment, the first cathode tab 31 and the second cathode tab 32 of the cathode electrode sheet 3 are configured such that, after the pre-winding of the cathode electrode sheet 3 is completed, the first cathode tab 31 is located within the first winding circle of the cathode electrode sheet 3, and the second cathode tab 32 is located within the second winding circle of the cathode electrode sheet 3, i.e., the second cathode tab 32 exceeds the first cathode tab 31, i.e., there is a surplus ΔL between the second cathode tab 32 and the first cathode tab 31. Thus, the thickness of the cathode electrode sheet 3 in the unfolded state can be further increased by the rolling device 60, so that the first cathode tab 31 and the second cathode tab 32, which were originally misaligned after the cathode electrode sheet 3 is wound, are aligned, i.e., the surplus ΔL of the cathode electrode sheet 3 after winding is changed from not equal to 0 to the surplus ΔL equal to 0.

[0071] Please refer to Figures 7, 8, 10 and 11. Figure 10 is a flow chart of determining embossing pressure provided in an embodiment of the present application. Figure 11 is a corresponding relationship diagram between embossing depth and embossing pressure provided in an embodiment of the present application.

[0072] In this embodiment, after the cathode plate 3 is wound, the first cathode tab 31 and the second cathode tab 32 on the cathode plate 3 are aligned.

[0073] S31 : According to the surplus amount ΔL and the winding parameters of the winding device 40 , the embossing depth y formed by the rolling device 60 is obtained.

[0074] S32: According to the corresponding relationship between the embossing depth y and the embossing pressure x, the embossing pressure x provided by the roller pressing device 60 is obtained.

[0075] Specifically, in step S31, the design surplus ΔL is a fixed value, and the specific value of the surplus ΔL shown in Figure 8 can be obtained by measuring the battery cell 10 after the cloud winding is completed. Since the winding device 40 is fixed, the winding parameters of the winding device 40 are also fixed values. As shown in Figures 7 and 8, the winding parameters of the winding device 40 include L1, L2, L3, R1 and R2. In order to ensure that the first cathode tab 31 and the second cathode tab 32 of the cathode plate 3 are overlapped and aligned after winding, the surplus ΔL satisfies: ΔL=π[(R1+y-R1)+(R2+y-R2)]=2πy. Therefore, according to the formula: y=ΔL / 2π, the embossing depth y that the rolling device 60 needs to form can be obtained.

[0076] Specifically, in step S32, as shown in FIG11 , assuming that the embossing depth is y and the embossing pressure is x, the embossing depth y and the embossing pressure x have a cubic function relationship. The embossing depth y and the embossing pressure x satisfy: y = ax 3 +bx 2 +cx+d, where a, b, c, and d are at least constants corresponding to the material used for the cathode plate 3 and the parameters of the rolling device 60. 3 +bx 2 +cx+d, and the determined value of the embossing depth y, the determined value of the embossing pressure x that the roller pressing device 60 needs to provide can be obtained.

[0077] In this embodiment, as shown in FIG11 , the relationship between the embossing depth y and the embossing pressure x is obtained based on the relationship constants corresponding to the material used for the cathode plate 3 and the parameters of the rolling device 60: y=-2554.7x 3 +2428.4x 2 -341.08x+15.045, and the regression equation of this relationship has R2=97.13%, which means the correlation is high. Therefore, the corresponding value errors of the embossing depth y and the embossing pressure x are small.

[0078] The method for winding a battery cell provided in this embodiment, first, by calculating the surplus amount ΔL of the surplus dislocation formed by the winding of the first cathode tab 31 and the second cathode tab 32 and the winding parameters of the winding device 40, the embossing depth y that the roller pressing device 60 needs to form on the cathode electrode 3 can be obtained, that is, the thickness of the cathode electrode 3 that needs to be increased by embossing treatment can be obtained. Then, through the data fitting analysis of the embossing depth y and the embossing pressure x, the specific correspondence between the embossing depth y and the embossing pressure x can be obtained to determine the fixed value of the embossing depth y, and then the fixed value of the embossing pressure x required to be provided for the embossing depth y can be obtained. By adjusting the fixed embossing pressure x provided by the roller pressing device 60, the cathode electrode 3 can increase in thickness under the action of the roller pressing device 60 and form a winding thickness with uniform thickness, wherein the winding thickness is the sum of the thickness of the cathode electrode 3 at a fixed position and the embossing depth y at a fixed position. As a result, the thickness of the cathode electrode sheet 3 is increased, so that the first cathode tab 31 and the second cathode tab 32 of the cathode electrode sheet 3 are aligned after winding. Moreover, the fixed embossing pressure x provided by the rolling device 60 makes the winding thickness of the cathode electrode sheet 3 more uniform, so that the other tabs on the cathode electrode sheet 3 can also be aligned with each other, which is beneficial to reduce the misalignment of the tabs on the cathode electrode sheet 3, thereby improving the winding yield of the battery cell 10.

[0079] Please refer to FIG. 12 , which is a schematic diagram of a process for determining the spacing between other cathode tabs on a cathode electrode sheet that are different from the first cathode tab and the second cathode tab, provided by an embodiment of the present application.

[0080] In this embodiment, after the cathode electrode sheet 3 is wound, the other cathode electrode tabs on the cathode electrode sheet 3 other than the first cathode electrode tab 31 and the second cathode electrode tab 32 are aligned.

[0081] S41 : According to the surplus amount ΔL and the winding parameters of the winding device 40 , the embossing depth y formed by the rolling device 60 is obtained.

[0082] S42 : according to the embossing depth y and the winding parameters of the winding device 40 , the spacing between the tabs on the cathode plate 3 that are different from the first cathode tab 31 and the second cathode tab 32 in the unfolded state is obtained.

[0083] Specifically, the specific method of step S41 is the same as the specific method of the aforementioned step S31, and will not be repeated here.

[0084] Specifically, in step S42, first, based on the structure and winding form of the second winding of the battery cell 10, the winding parameters of the first separator 11, the cathode electrode sheet 3, the second separator 12, and the anode electrode sheet 5 can be obtained. Then, combined with the embossing depth y and the winding parameters of the winding device 40, the spacing between the tabs on the cathode electrode sheet 3 that are different from the first cathode tab 31 and the second cathode tab 32 in the unfolded state can be obtained.

[0085] The method for winding a battery cell provided in an embodiment of the present application first calculates the surplus amount ΔL of the surplus misalignment formed by the first cathode tab 31 and the second cathode tab 32 during winding and the winding parameters of the winding device 40, and thus the embossing depth y that the roller pressing device 60 needs to form on the cathode plate 3, that is, the thickness of the cathode plate 3 that needs to be increased by the embossing process can be obtained. Then, by calculating the embossing depth y and the winding parameters of the winding device 40 for winding the first separator 11, the cathode plate 3, the second separator 12, and the anode plate 5, the spacing between the other tabs on the cathode plate 3 that are different from the first cathode tab 31 and the second cathode tab 32 in the unfolded state can be obtained, so that the cathode plate 3 is configured such that after the winding is completed, the other tabs on the cathode plate 3 that are different from the first cathode tab 31 and the second cathode tab 32 are aligned. Therefore, by designing the spacing between the other cathode tabs 31 and the second cathode tab 32 on the cathode plate 3 in the unfolded state, the tabs on the cathode plate 3 are aligned after the winding is completed, thereby improving the winding yield of the battery cell 10.

[0086] Please refer to Figures 13 and 14. Figure 13 is a flow chart of determining the spacing between the first cathode tab and the second cathode tab on a cathode electrode sheet provided by another embodiment of the present application. Figure 14 is a correspondence diagram between the misalignment amount of the cathode tab and the embossing pressure provided by an embodiment of the present application.

[0087] In this embodiment, after the cathode plate 3 is wound, the first cathode tab 31 and the second cathode tab 32 on the cathode plate 3 are aligned.

[0088] S51: according to the corresponding relationship between the misalignment amount z1 of the tab on the cathode electrode sheet 3 and the embossing pressure x, the embossing pressure x provided by the rolling device 60 is obtained.

[0089] S52: According to the corresponding relationship between the embossing depth y and the embossing pressure x, the embossing depth y formed by the roller pressing device 60 is obtained.

[0090] S53: According to the embossing depth y and the winding parameters of the winding device 40 , the value of the surplus amount ΔL is obtained, and then the distance between the first cathode tab 31 and the second cathode tab 32 in the unfolded state is obtained.

[0091] Specifically, in step S51, as shown in FIG14 , the misalignment amount of the tab on the cathode electrode piece 3 is z1, the embossing pressure is x, and the misalignment amount z1 of the tab on the cathode electrode piece 3 and the embossing pressure x present a quadratic function relationship. The misalignment amount z1 of the tab on the cathode electrode piece 3 and the embossing pressure x satisfy: z1 = fx 2+gx+h, where f, g, and h are at least the constants corresponding to the material used for the cathode plate 3 and the parameters of the front station. 2 +gx+h, and the minimum value of the offset z1 of the tab on the cathode plate 3 (z1=0), the determined value of the embossing pressure x that the rolling device 60 needs to provide can be obtained.

[0092] In this embodiment, as shown in FIG14 , the relationship between the misalignment z1 of the tab on the cathode plate 3 and the embossing pressure x is obtained based on the relationship constants corresponding to the material used in the cathode plate 3 and the front-end parameters: z1 = -11526x 2 +539.27x+89.426, and the regression equation of this relationship R2=99.45%, which has a high correlation. Therefore, the corresponding value errors of the misalignment amount z1 of the tab on the cathode electrode 3 and the embossing pressure x are small.

[0093] Specifically, in step S52, as shown in FIG11 , assuming that the embossing depth is y and the embossing pressure is x, the embossing depth y and the embossing pressure x have a cubic function relationship. The embossing depth y and the embossing pressure x satisfy: y = ax 3 +bx 2 +cx+d, where a, b, c, and d are at least constants corresponding to the material used for the cathode plate 3 and the parameters of the rolling device 60. 3 +bx 2 +cx+d, and the determined value of the embossing pressure x, the determined value of the embossing depth y that the roller pressing device 60 needs to provide can be obtained.

[0094] Specifically, in step S53, since the embossing depth y is a fixed value and the winding device 40 is fixed, the winding parameters of the winding device 40 are also fixed values. As shown in Figures 7 and 8, the winding parameters of the winding device 40 include L1, L2, L3, R1, and R2. To ensure that the first cathode tab 31 and the second cathode tab 32 of the cathode plate 3 are aligned after winding, the calculation formula for the margin ΔL can be obtained: ΔL = π[(R1 + y - R1) + (R2 + y - R2)] = 2πy. This can then be used to calculate the spacing between the first cathode tab 31 and the second cathode tab 32 in the unfolded state.

[0095] The method for winding a battery cell provided in an embodiment of the present application first obtains the specific correspondence between the misalignment z1 of the tab on the cathode electrode 3 and the embossing pressure x based on the data fitting analysis of the misalignment z1 of the tab on the cathode electrode 3, and the embossing pressure x, and then obtains the embossing pressure x that the roller pressing device 60 needs to provide corresponding to the smaller misalignment z1 of the tab on the cathode electrode 3. Then, based on the correspondence between the embossing depth y and the embossing pressure x, the embossing depth y that the roller pressing device 60 needs to form is obtained. Finally, by calculating the embossing depth y and the winding parameters of the winding device 40, a fixed value of the surplus amount ΔL of the first cathode tab 31 and the second cathode tab 32 is obtained, and then a fixed spacing between the first cathode tab 31 and the second cathode tab 32 in the unfolded state can be obtained. Thus, the increase in the thickness of the cathode electrode 3 can offset the surplus amount of the misalignment of the first cathode tab 31 and the second cathode tab 32, so that the first cathode tab 31 and the second cathode tab 32 are aligned after the cathode electrode 3 is wound.

[0096] Please refer to FIG. 15 , which is a schematic diagram of a process for determining the spacing between other cathode tabs on a cathode electrode sheet that are different from the first cathode tab and the second cathode tab, provided by an embodiment of the present application.

[0097] In this embodiment, after the cathode electrode sheet 3 is wound, the tabs on the cathode electrode sheet 3 that are different from the first cathode tab 31 and the second cathode tab 32 are aligned.

[0098] S61: according to the corresponding relationship between the misalignment amount z1 of the tab on the cathode electrode sheet 3 and the embossing pressure x, the embossing pressure x provided by the rolling device 60 is obtained.

[0099] S62: According to the corresponding relationship between the embossing depth y and the embossing pressure x, the embossing depth y formed by the roller pressing device 60 is obtained.

[0100] S63 : according to the embossing depth y and the winding parameters of the winding device 40 , the spacing between the tabs on the cathode plate 3 that are different from the first cathode tab 31 and the second cathode tab 32 in the unfolded state is obtained.

[0101] Specifically, the specific method of step S61 is the same as the specific method of the aforementioned step S51, and will not be repeated here.

[0102] Specifically, the specific method of step S62 is the same as the specific method of the aforementioned step S52, and will not be repeated here.

[0103] Specifically, in step S63, first, based on the structure and winding form of the second winding of the battery cell 10, the winding parameters of the first separator 11, the cathode electrode sheet 3, the second separator 12, and the anode electrode sheet 5 can be obtained. Then, combined with the embossing depth y and the winding parameters of the winding device 40, the spacing between the tabs on the cathode electrode sheet 3 that are different from the first cathode tab 31 and the second cathode tab 32 in the unfolded state can be obtained.

[0104] The method for winding a battery cell provided in an embodiment of the present application is as follows: first, based on the correspondence between the misalignment amount z1 of the tab on the cathode electrode 3 and the embossing pressure x, the embossing pressure x that the rolling device 60 needs to provide can be obtained, and then the embossing pressure x that the rolling device 60 needs to provide corresponding to the misalignment amount z1 of the tab on the smaller cathode electrode 3 can be obtained. Then, based on the correspondence between the embossing depth y and the embossing pressure x, the fixed value of the embossing depth y on the cathode electrode 3 can be obtained, and then the winding thickness value of the cathode electrode 3 can be obtained. Finally, by calculating the embossing depth y and the winding parameters of the winding device 40, the spacing between the other tabs on the cathode electrode 3 that are different from the first cathode electrode 31 and the second cathode electrode 32 in the unfolded state can be obtained, so that the cathode electrode 3 is configured as follows: after the winding is completed, the other tabs on the cathode electrode 3 that are different from the first cathode electrode 31 and the second cathode electrode 32 are aligned. Therefore, by designing the spacing between the other cathode tabs 31 and the second cathode tab 32 on the cathode plate 3 in the unfolded state, the tabs on the cathode plate 3 are aligned after the winding is completed, thereby improving the winding yield of the battery cell 10.

[0105] Please refer to Figures 16 and 17. Figure 16 is a flow chart of determining the spacing between the first cathode tab and the second cathode tab on a cathode electrode sheet provided by another embodiment of the present application. Figure 17 is a correspondence diagram of the misalignment amount and embossing pressure of the anode tab provided by an embodiment of the present application.

[0106] In this embodiment, after the cathode plate 3 is wound, the first cathode tab 31 and the second cathode tab 32 on the cathode plate 3 are aligned.

[0107] S71: according to the corresponding relationship between the misalignment amount z2 of the tab on the anode electrode sheet 5 and the embossing pressure x, the embossing pressure x provided by the rolling device 60 is obtained.

[0108] S72: According to the corresponding relationship between the embossing depth y and the embossing pressure x, the embossing depth y formed by the roller pressing device 60 is obtained.

[0109] S73: According to the embossing depth y and the winding parameters of the winding device 40 , the value of the surplus amount ΔL is obtained, and then the distance between the first cathode tab 31 and the second cathode tab 32 in the unfolded state is obtained.

[0110] Specifically, in step S71, as shown in FIG17 , the misalignment amount of the tab on the anode plate 5 is z2, the embossing pressure is x, and the misalignment amount z2 of the tab on the anode plate 5 and the embossing pressure x are in a quadratic function relationship. The misalignment amount z2 of the tab on the anode plate 5 and the embossing pressure x satisfy: z2=lx 2 +mx+n, where l, m, and n are at least the relationship constants corresponding to the material used for the cathode plate 3 and the parameters of the front station. 2 +mx+n, and the minimum value of the misalignment z2 of the tab on the anode plate 5 (z2=0), the determined value of the embossing pressure x that the rolling device 60 needs to provide can be obtained.

[0111] In this embodiment, as shown in FIG17 , the relationship between the misalignment z2 of the tab on the anode plate 5 and the embossing pressure x is obtained based on the relationship constants corresponding to the material used in the anode plate 5 and the parameters of the front station: z2 = -12807x 2 +783.37x+73.748, and the regression equation of this relationship R2=98.57%, which has a high correlation. Therefore, the corresponding value errors of the misalignment amount z2 of the tab on the anode electrode sheet 5 and the embossing pressure x are small.

[0112] Specifically, the specific method of step S72 is the same as the specific method of the aforementioned step S52, and will not be repeated here.

[0113] Specifically, the specific method of step S73 is the same as the specific method of the aforementioned step S53, and will not be repeated here.

[0114] The method for winding a battery cell provided in an embodiment of the present application first obtains the specific correspondence between the misalignment z2 of the tab on the anode plate 5 and the embossing pressure x based on the data fitting analysis, and then obtains the embossing pressure x that the roller pressing device 60 needs to provide for the smaller misalignment z2 of the tab on the anode plate 5. Then, based on the correspondence between the embossing depth y and the embossing pressure x, the embossing depth y that the roller pressing device 60 needs to form is obtained. Finally, by calculating the embossing depth y and the winding parameters of the winding device 40, the fixed value of the surplus amount ΔL of the first cathode tab 31 and the second cathode tab 32 is obtained, and then the fixed spacing between the first cathode tab 31 and the second cathode tab 32 in the unfolded state can be obtained. Thus, the increase in the thickness of the cathode plate 3 can offset the surplus amount of the misalignment of the first cathode tab 31 and the second cathode tab 32, so that the first cathode tab 31 and the second cathode tab 32 are aligned after the cathode plate 3 is wound.

[0115] Please refer to FIG. 18 , which is a schematic diagram of a process for determining the spacing between other cathode tabs on a cathode electrode sheet that are different from the first cathode tab and the second cathode tab, provided by another embodiment of the present application.

[0116] In this embodiment, after the cathode electrode sheet 3 is wound, the tabs on the cathode electrode sheet 3 that are different from the first cathode tab 31 and the second cathode tab 32 are aligned.

[0117] S81: According to the corresponding relationship between the misalignment amount z2 of the tab on the anode electrode sheet 5 and the embossing pressure x, the embossing pressure x provided by the rolling device 60 is obtained.

[0118] S82: According to the corresponding relationship between the embossing depth y and the embossing pressure x, the embossing depth y formed by the roller pressing device 60 is obtained.

[0119] S83: According to the embossing depth y and the winding parameters of the winding device 40 , the spacing between the tabs on the cathode plate 3 that are different from the first cathode tab 31 and the second cathode tab 32 in the unfolded state is obtained.

[0120] Specifically, the specific method of step S81 is the same as the specific method of the aforementioned step S71, and will not be repeated here.

[0121] Specifically, the specific method of step S82 is the same as the specific method of the aforementioned step S72, and will not be repeated here.

[0122] Specifically, the specific method of step S83 is the same as the specific method of the aforementioned step S63, and will not be repeated here.

[0123] The method for winding a battery cell provided in an embodiment of the present application is as follows: first, based on the correspondence between the misalignment z2 of the tab on the anode electrode 5 and the embossing pressure x, the embossing pressure x that the rolling device 60 needs to provide can be obtained, and then the embossing pressure x that the rolling device 60 needs to provide corresponding to the misalignment z2 of the tab on the smaller anode electrode 5 can be obtained. Then, based on the correspondence between the embossing depth y and the embossing pressure x, the fixed value of the embossing depth y on the cathode electrode 3 can be obtained, and then the winding thickness value of the cathode electrode 3 can be obtained. Finally, by calculating the embossing depth y and the winding parameters of the winding device 40, the spacing between the other tabs on the cathode electrode 3 that are different from the first cathode electrode 31 and the second cathode electrode 32 in the unfolded state can be obtained, so that the cathode electrode 3 is configured as follows: after the winding is completed, the other tabs on the cathode electrode 3 that are different from the first cathode electrode 31 and the second cathode electrode 32 are aligned. Therefore, by designing the spacing between the other cathode tabs 31 and the second cathode tab 32 on the cathode plate 3 in the unfolded state, the tabs on the cathode plate 3 are aligned after the winding is completed, thereby improving the winding yield of the battery cell 10.

[0124] The above are some implementation methods of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications are also considered to be within the scope of protection of the present application.

Claims

1. A method for winding a battery cell, wherein: include: Incoming materials, obtaining a separator, a cathode electrode sheet and an anode electrode sheet; the cathode electrode sheet of the incoming materials meets the following requirements: after the pre-winding is completed, a first cathode electrode ear and a second cathode electrode ear adjacently arranged near the winding end of the cathode electrode sheet form a surplus misalignment; Rolling up, fixing the starting ends of the diaphragm, the cathode electrode sheet and the anode electrode sheet on a winding device; Embossing, embossing the cathode electrode sheet through a roller pressing device, so that the cathode electrode sheet after embossing satisfies: after winding, the first cathode electrode ear is aligned with the second cathode electrode ear; as well as Winding: Winding the separator, the cathode electrode sheet and the anode electrode sheet through the winding device.

2. The method of claim 1, wherein: In the material incoming step, the surplus misalignment satisfies: after the pre-winding is completed, the first cathode pole ear is located in the first circle, and the second cathode pole ear is located in the second circle; there is a surplus of the second cathode pole ear relative to the first cathode pole ear, and the surplus is the distance from the geometric center of the first cathode pole ear to the geometric center of the second cathode pole ear along the winding trajectory.

3. The method of claim 2, wherein: According to the surplus amount and the winding parameters of the winding device, the embossing depth formed by the rolling device is obtained; The embossing pressure provided by the rolling device is obtained according to the corresponding relationship between the embossing depth and the embossing pressure, so that the first cathode tab and the second cathode tab are aligned after the winding of the cathode electrode sheet is completed.

4. The method of claim 3, wherein: The embossing depth and the embossing pressure present a cubic function relationship; Assume that the embossing depth is y, and the embossing pressure is x. The embossing depth y and the embossing pressure x satisfy: y=ax 3 +bx 2 +cx+d, where a, b, c, d are at least the relationship constants corresponding to the material used for the cathode plate and the parameters of the rolling device; according to y=ax 3 +bx 2 +cx+d, and the embossing depth y, to obtain the embossing pressure x provided by the rolling device.

5. The method of claim 2, wherein: According to the surplus amount and the winding parameters of the winding device, the embossing depth formed by the rolling device is obtained; According to the embossing depth and the winding parameters of the winding device, the spacing between the cathode pole pieces different from the first cathode pole pieces and the second cathode pole pieces in the unfolded state is obtained, so that after the winding of the cathode pole piece is completed, the cathode pole pieces different from the first cathode pole pieces and the second cathode pole pieces are aligned.

6. The method of claim 2, wherein: According to the corresponding relationship between the misalignment amount of the tab on the cathode electrode sheet and the embossing pressure, the embossing pressure provided by the rolling device is obtained; According to the corresponding relationship between the embossing depth and the embossing pressure, the embossing depth formed by the roller pressing device is obtained; The value of the surplus amount is obtained according to the embossing depth and the winding parameters of the winding device, and then the distance between the first cathode tab and the second cathode tab in the unfolded state is obtained.

7. The method of claim 6, wherein: The misalignment amount of the tab on the cathode electrode sheet and the embossing pressure are in a quadratic function relationship; Assume that the misalignment of the tab on the cathode electrode sheet is z1, and the embossing pressure is x. The misalignment of the tab on the cathode electrode sheet z1 and the embossing pressure x satisfy: z1=fx 2 +gx+h, wherein f, g, and h are at least the relationship constants corresponding to the material used for the cathode electrode.

8. The method of claim 2, wherein: In the embossing step: According to the corresponding relationship between the misalignment amount of the tab on the cathode electrode sheet and the embossing pressure, the embossing pressure provided by the rolling device is obtained; According to the corresponding relationship between the embossing depth and the embossing pressure, the embossing depth formed by the roller pressing device is obtained; According to the embossing depth and the winding parameters of the winding device, the spacing between the cathode pole pieces different from the first cathode pole pieces and the second cathode pole pieces in the unfolded state is obtained, so that after the winding of the cathode pole piece is completed, the cathode pole pieces different from the first cathode pole pieces and the second cathode pole pieces are aligned.

9. The method of claim 2, wherein: According to the corresponding relationship between the misalignment amount of the tab on the anode electrode sheet and the embossing pressure, the embossing pressure provided by the rolling device is obtained; According to the corresponding relationship between the embossing depth and the embossing pressure, the embossing depth formed by the roller pressing device is obtained; The value of the surplus amount is obtained according to the embossing depth and the winding parameters of the winding device, and then the distance between the first cathode tab and the second cathode tab in the unfolded state is obtained.

10. The method of claim 9, wherein: The misalignment amount of the tab on the anode electrode sheet and the embossing pressure are in a quadratic function relationship; Assume that the misalignment amount of the tab on the anode electrode sheet is z2, the embossing pressure is x, and the misalignment amount of the tab on the anode electrode sheet is z2 and the embossing pressure x satisfies: z2=lx 2 +mx+n, wherein l, m, and n are at least the relationship constants corresponding to the material used for the cathode electrode.

11. The method of claim 2, wherein: In the embossing step: According to the corresponding relationship between the misalignment amount of the tab on the anode electrode sheet and the embossing pressure, the embossing pressure provided by the rolling device is obtained; According to the corresponding relationship between the embossing depth and the embossing pressure, the embossing depth formed by the roller pressing device is obtained; According to the embossing depth and the winding parameters of the winding device, the spacing between the cathode pole pieces different from the first cathode pole pieces and the second cathode pole pieces in the unfolded state is obtained, so that after the winding of the cathode pole piece is completed, the cathode pole pieces different from the first cathode pole pieces and the second cathode pole pieces are aligned.

12. A battery cell winding system, wherein: include: A feeding device for providing a diaphragm, a cathode electrode piece and an anode electrode piece; The incoming cathode electrode sheet meets the following requirements: after the pre-winding is completed, the first cathode electrode ear and the second cathode electrode ear adjacent to each other at the winding end of the cathode electrode sheet form a surplus misalignment; A rolling device is used to perform embossing on the cathode electrode sheet, so that the cathode electrode sheet after embossing satisfies: after winding is completed, the first cathode electrode ear is aligned with the second cathode electrode ear; as well as The winding device is used to fix the starting ends of the diaphragm, the cathode electrode sheet and the anode electrode sheet, and to wind the diaphragm, the cathode electrode sheet and the anode electrode sheet.

13. The battery cell winding system according to claim 12, wherein: The rolling device comprises a bracket, a first pressing roller, a first driving member, a second pressing roller, a second driving member and a control valve; The first pressing roller is rotatably disposed on the bracket; The first driving member is used to drive the first pressing roller to rotate; The second pressing roller is rotatably disposed on the bracket, and the second pressing roller is disposed parallel to the first pressing roller; The second driving member is used to drive the first pressing roller to move closer to or away from the second pressing roller, so as to adjust the embossing pressure of the rolling device; The control valve is electrically connected to the second driving member to control the distance that the second driving member drives the first pressing roller to move toward or away from the second pressing roller.

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