A pole piece winding method

Abstract

The application belongs to the technical field of battery manufacturing, and discloses a pole piece winding method, which comprises the following steps: in response to the fact that a preset condition is met, detecting the angle through which a winding needle is turned, and setting the actual angle Φ; according to preset angle data, calculating the actual deviation value ΔΦ corresponding to the actual angle Φ; comparing the absolute value of the actual deviation value ΔΦ with a preset deviation value E, and in the case that the absolute value of the actual deviation value ΔΦ exceeds the preset deviation value E, adjusting the thickness of the pole piece according to the actual deviation value ΔΦ to wind the pole piece. The method can monitor the alignment degree of the pole lug in real time during the winding process and automatically adjust the alignment degree of the pole lug according to the misalignment amount of the pole lug, thereby improving the adjustment accuracy and reducing the waste rate.

Description

Technical Field

[0001] This invention relates to the field of battery manufacturing technology, and in particular to a method for winding electrode sheets. Background Technology

[0002] As the length of the electrode sheet and the number of tabs increase in existing wound cells, the requirements for the consistency of the electrode sheet thickness become increasingly stringent. When the electrode sheet thickness fluctuates, it will cause the tabs to misalign during the winding process, thereby increasing the scrap rate of wound cells.

[0003] To improve the problem of misaligned electrodes, the conventional methods are to correct the position of the Teflon coating on the winding needle or to use a variable diameter winding needle to adjust the electrode alignment. However, these methods often have a certain lag and cannot detect and adjust the misalignment in time. In practical applications, adjustment is often only possible after several cells have been misaligned, and the adjustment amount relies on the operator's experience, making it impossible to ensure that the adjustment is correct on the first attempt, which may result in more defective products.

[0004] Therefore, there is an urgent need to propose a method that can monitor the tab alignment in real time during the winding process and automatically adjust the tab alignment according to the amount of tab misalignment. Summary of the Invention

[0005] The purpose of this invention is to provide an electrode winding method that monitors the electrode tab alignment in real time during the winding process and automatically adjusts the electrode thickness according to the amount of electrode tab misalignment, thereby ensuring electrode tab alignment and reducing scrap rate.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] This invention discloses an electrode winding method, comprising the following steps: in response to satisfying a preset condition, detecting the angle through which the winding needle has rotated, and setting it as the actual angle Φ; calculating the actual deviation value ΔΦ corresponding to the actual angle Φ based on preset angle data; comparing the absolute value of the actual deviation value ΔΦ with a preset deviation value E; and if the absolute value of the actual deviation value ΔΦ exceeds the preset deviation value E, adjusting the thickness of the electrode according to the actual deviation value ΔΦ to wind the electrode.

[0008] The electrode winding method of the present invention has the following advantages: In the method provided by the present invention, in response to the satisfaction of a preset condition, the angle through which the winding needle has rotated is detected and set as the actual angle Φ; then, based on the preset angle data, the actual deviation value ΔΦ corresponding to the actual angle Φ is calculated, and the absolute value of the actual deviation value ΔΦ is compared with the preset deviation value E; if the absolute value of the actual deviation value ΔΦ exceeds the preset deviation value E, it is determined that the electrode tab has deviated. Furthermore, after detecting a deviation in the electrode tab, the thickness of the electrode sheet can be adjusted according to the actual deviation value ΔΦ, thereby compensating for the misalignment of the electrode tab during the winding process. This achieves real-time monitoring of the electrode tab alignment during the winding process and automatic adjustment of the electrode tab alignment based on the misalignment, improving adjustment accuracy and reducing the scrap rate. Attached Figure Description

[0009] Figure 1 This is a schematic flowchart of the electrode winding method according to an embodiment of the present invention;

[0010] Figure 2 This is a schematic diagram of the winding device;

[0011] Figure 3 This is a schematic diagram of the structure of a reference battery cell according to an embodiment of the present invention;

[0012] Figure 4 This is a schematic diagram of the structure of the misaligned battery cell according to an embodiment of the present invention;

[0013] Figure 5 This is a schematic diagram of the electrode structure according to an embodiment of the present invention.

[0014] Figure label:

[0015] 100. Coiling needle; 200. Electrode sheet; 210. Positive electrode sheet; 220. Negative electrode sheet; 201. Electrode tab; 300. Electrode tab detection device; 400. Shaping roller; 500. Reference cell; 600. Deviation cell; 700. Upper diaphragm; 800. Lower diaphragm. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the invention and not all structures. Those skilled in the art will understand the specific meanings of the terms used in the invention based on the specific circumstances. In the description of this embodiment, terms such as "upper," "lower," "left," "right," "front," and "rear," etc., refer to the orientation or positional relationships shown in the accompanying drawings, and are used only for ease of description and simplification of operation, not to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0017] This invention discloses an electrode winding method, with reference to... Figure 1 As shown, the electrode winding method includes the following steps: S1: In response to meeting the preset conditions, the angle rotated by the winding needle 100 is detected and set as the actual angle Φ; S2: Based on the preset angle data, the actual deviation value ΔΦ corresponding to the actual angle Φ is calculated; S3: The absolute value of the actual deviation value ΔΦ is compared with the preset deviation value E. If the absolute value of the actual deviation value ΔΦ exceeds the preset deviation value E, the thickness of the electrode 200 is adjusted according to the actual deviation value ΔΦ to wind the electrode 200.

[0018] First, it should be noted that during the actual winding process, electrode 200 is equipped with electrode tabs. Since the die-cutting parameters are consistent for each EA, refer to... Figure 5 As shown, the spacing between multiple tabs 201 within the tab group on the electrode sheet 200 gradually increases. If the thickness of the electrode sheet 200 remains constant, then during the winding process, the tabs 201 of adjacent layers will be basically aligned and there will be no deviation. However, due to manufacturing reasons, the thickness of the electrode sheet 200 will not be completely consistent. In this case, during the winding process, the tabs 201 of adjacent layers will deviate. It is understood that in the electrode winding method provided by this invention, in response to meeting the preset conditions, the angle rotated by the winding needle 100 is detected and set as the actual angle Φ; based on the preset angle data, the actual deviation value ΔΦ corresponding to the actual angle Φ is calculated, and the absolute value of the actual deviation value ΔΦ is compared with the preset deviation value E; when the absolute value of the actual deviation value ΔΦ exceeds the preset deviation value E, it is determined that the tabs 201 of the cell have deviated (refer to...). Figure 4 As shown, Figure 4The diagram shows a battery cell 600 with a deviated tab 201. The tab 201 needs to be corrected. During the correction process, the thickness of the electrode 200 can be adjusted based on the actual deviation value ΔΦ to wind the electrode 200, thereby correcting the tab alignment. When the absolute value of the actual deviation value ΔΦ is less than the preset deviation value E, it indicates that the alignment of the battery cell's tab 201 is good, and it can be determined that the tab 201 of the battery cell has no deviation and does not require correction.

[0019] In summary, the electrode winding method provided by this invention enables real-time monitoring of the electrode alignment during the winding process, and can automatically adjust the electrode alignment according to the misalignment of the electrode 201, thereby improving the adjustment accuracy, reducing the scrap rate, and triggering detection conditions by the electrode position, so that the detected angle value is more consistent with the actual situation of the battery cell, and can better ensure the electrode alignment.

[0020] Optionally, the preset deviation value E is 0.05°-0.5°. Specifically, the preset deviation value E can be 0.05°, 0.1°, 0.15°, 0.2°, 0.25°, 0.3°, 0.35°, 0.4°, 0.45°, or 0.5°. Of course, the preset deviation value E can also be selected from other values ​​within the range of 0.05°-0.5° according to actual needs, and is not limited to the examples above. It can be understood that the smaller the preset deviation value E is set, the more adjustments are made to the thickness of the electrode sheet 200, resulting in better electrode alignment of the wound cell, but lower efficiency. Conversely, the larger the preset deviation value E is set, the fewer adjustments are made to the thickness of the electrode sheet 200, resulting in poorer electrode alignment of the wound cell, but higher efficiency. In actual operation, the design needs to comprehensively consider the production requirements for electrode alignment and production efficiency to achieve both good electrode alignment and high production efficiency in the wound cell.

[0021] Steps S1, S2, and S3 are described in detail below.

[0022] In step S1, the preset conditions include detecting tabs on the electrode 200. Specifically, refer to... Figure 5 As shown, the electrode sheet 200 is provided with multiple tab groups, each tab group including multiple tabs 201. The preset condition is that one tab 201 within the tab group is detected. It can be understood that during the actual winding process, the electrode sheet raw material roll is continuously output, and the winding needle 100 continuously rotates. The tab 201 is detected by the tab detection device 300 on the winding equipment, and this is used as the preset condition. Since the tab 201 has a certain width, refer to... Figure 5As shown, when the tab detection device 300 detects position a on the tab 201, it can be determined that the tab detection device 300 has detected the tab 201. Selecting the detection of the tab 201 as a preset condition facilitates the execution logic of the design method and requires minimal modification to the winding equipment, making it easy to implement.

[0023] It should be further explained that, since electrode 200 includes positive electrode 210 and negative electrode 220, and the tab group includes positive tab group and negative tab group, the preset conditions include detecting multiple positive tabs in the positive tab group and / or detecting multiple negative tabs in the negative tab group. In actual operation, detecting either positive or negative tabs can be used as preset conditions. Regardless of the situation, the principle of adjusting the thickness of electrode 200 according to the actual deviation value ΔΦ is the same. The only difference is the meaning represented by the actual deviation value ΔΦ and the specific type of electrode 200 being adjusted, as detailed below:

[0024] The preset condition is that when the positive electrode tab in the positive electrode tab group is detected, the angle through which the winding needle 100 turns is set to the actual angle Φ positive. The difference between the actual angle Φ positive and the preset angle value A is the actual deviation value ΔΦ. At this time, the thickness of the positive electrode sheet 210 can be adjusted according to the actual deviation value ΔΦ.

[0025] The preset condition is that when the positive electrode tab in the negative electrode tab group is detected, the angle through which the winding needle 100 turns is set to the actual angle Φ negative. The difference between the actual angle Φ negative and the preset angle value A is the actual deviation value ΔΦ. At this time, the thickness of the negative electrode sheet 220 can be adjusted according to the actual deviation value ΔΦ.

[0026] When the preset condition is that a positive electrode tab within the positive electrode tab and a negative electrode tab within the negative electrode tab group are detected, the actual angles Φpositive and Φnegative will be obtained. At this point, the difference between the actual angle Φpositive and the preset angle value A is set as the first difference, and the difference between the actual angle Φnegative and the preset angle value A is set as the second difference. The actual deviation value ΔΦ is the average of the first and second differences. At this time, the thickness of the positive electrode 210, the thickness of the negative electrode 220, or both the positive and negative electrode 210 can be adjusted based on the actual deviation value ΔΦ.

[0027] It should be further explained that, in this case, both the positive electrode 210 and the negative electrode 220 are equipped with tab detection devices 300, which are respectively set as positive tab detection devices and negative tab detection devices. The preset conditions can be that the positive tab detection device detects the positive tab at the same time as the negative tab detection device detects the negative tab, or the positive tab detection device detects the i-th positive tab in the positive tab group first, and then the negative tab detection device detects the i-th negative tab in the negative tab group first. After the i-th negative tab is detected, the actual deviation value ΔΦ is obtained according to the actual angle Φ being positive and the actual angle Φ being negative.

[0028] Optionally, the preset condition is a delay of a preset time after detecting tab 201. It is understandable that during actual production and transportation, the electrode 200 may contain foreign objects or other manufacturing deviations, which can interfere with the detection accuracy of the tab detection device 300. The preset condition of a delay after detecting tab 201 means that in actual operation, the time point at which the tab detection device 300 detects tab 201 is T0, but the time point at which the recording needle 100 has rotated through an angle is T1. T1 is T0 + the preset time. This method of delaying the recording of the rotation of the needle 100 ensures that the time of recording the rotation of the needle 100 is the time when the tab detection device 300 detects tab 201, not the time of the interfering object. This improves the accuracy of recording the rotation of the needle 100, obtaining a more accurate actual angle Φ, and thus enabling more accurate adjustment of the thickness of the electrode 200.

[0029] In step S2, the preset angle data includes at least one preset angle value A, and each preset angle value A has a corresponding number of winding turns of the winding needle. Specifically, during batch production, all cells produced by winding undergo quality inspection. Cells in a batch with a tab deviation δ less than a preset deviation δ0 are used as the reference cell 500. Figure 3 (The battery cell shown) Then, when the reference battery cell 500 is wound, the angle through which the winding needle 100 rotates when multiple tabs 201 are detected in sequence is taken as the preset angle value A. And according to the number of turns of the winding needle during the detection process, the preset angle data is set as an array. That is, when manufacturing the reference battery cell 500, when the tab detection device 300 senses the first tab 201, the second tab 201, the third tab 201... the Nth tab 201, the angle detection device on the winding needle 100 will detect N angle values. According to the number of turns of the winding needle 100, the control system of the winding equipment can store a standard array {A1, A2, A3... AN} including N preset angle values ​​A. This standard array is used as the preset angle data in step S2.

[0030] Once the preset angle data is determined, during the subsequent cell production process, when the electrode detection device 300 senses the first electrode 201, the second electrode 201, the third electrode 201... the Nth electrode 201, the angle detection device on the winding needle 100 will also obtain N angle values. Based on the number of turns of the winding needle 100, a detection array {Φ1, Φ2, Φ3... ΦN} is obtained sequentially. Each value in the detection array is an actual angle Φ, and each actual angle Φ will have a corresponding current winding number m of the winding needle (for example, Φ1 represents the actual angle when the current winding number of the winding needle is 1).

[0031] As described above, calculating the actual deviation value ΔΦ corresponding to the actual angle Φ includes: obtaining the target preset angle value Am corresponding to the current number of winding turns m of the winding needle based on preset angle data; calculating the difference between the actual angle Φ and the target preset angle value Am to obtain the actual deviation value ΔΦ. Specifically, when Φ1 is measured, it is compared with A1 to obtain a difference, which can be set as ΔΦ1. If the absolute value of ΔΦ1 is greater than the preset deviation value E, it indicates that the electrode 201 has already deviated when the second electrode 201 is detected. Specifically, if ΔΦ1 is a negative value, it indicates that the thickness of the electrode 200 is too large, and the thickness of the electrode 200 needs to be reduced in the subsequent time period. If ΔΦ1 is a positive value, it indicates that the thickness of the electrode 200 is too small, and the thickness of the electrode 200 needs to be increased in the subsequent time period, thereby adjusting the electrode alignment, avoiding defective electrode alignment and improving the yield rate.

[0032] Optionally, the preset deviation δ0 ranges from 0.5mm to 10mm. Specifically, the preset deviation δ0 can be 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, or 10mm. Of course, the tab deviation δ can also be selected from other values ​​within the 0.5mm-10mm range, and is not limited to the examples above. It should be noted that the preset deviation amount δ0 needs to be determined according to the actual production requirements of the wound battery cell. If the preset deviation amount δ0 is too large, it will increase the scrap rate. If the preset deviation amount δ0 is too small, it will lead to too many adjustments to the thickness of the electrode 200 during the winding process, affecting normal production efficiency. In this embodiment, the preset deviation amount δ0 is controlled within the range of 0.5mm-10mm. This can ensure the production yield, reduce the number of defective products (products with excessive electrode deviation δ), and control the number of adjustments to the thickness of the electrode 200, thus ensuring production efficiency.

[0033] Optionally, each time a cell is wound, the tab deviation δ of the cell is detected. If the tab deviation δ of the newly wound cell is less than the tab deviation δ of the reference cell 500, the original reference cell 500 is replaced by the newly wound cell, and a preset angle value A is determined based on the newly wound cell. It is understandable that in actual manufacturing, the tab alignment of each newly wound cell may be better or worse than the previously determined reference cell 500. During the implementation of the method, the tabs 201 of the newly wound cell are compared with the original reference cell 500, and the reference cell 500 is updated in real time. This maximizes the improvement of the tab alignment of each subsequent wound cell, thereby improving the manufacturing yield of the cells.

[0034] In step S3, the thickness of the electrode 200 is adjusted according to the actual deviation value ΔΦ. This includes calculating a pressure adjustment value F based on the actual deviation value ΔΦ. The pressure adjustment value F is used to correct the pressure applied to the electrode 200 by the forming roller 400, thereby adjusting the thickness of the electrode 200. It is understood that adjusting the thickness of the electrode 200 by adjusting the pressure applied to the electrode 200 by the forming roller 400 is convenient for the execution logic of the design method and requires minimal modification to the winding equipment, making it easy to implement.

[0035] Optionally, the actual deviation value ΔΦ and the pressure adjustment value F satisfy the following relationship:

[0036] F=(((L0 / 360)*(ΔΦ / m)) / J)*K+λ;

[0037] Wherein: L0 is the initial circumference of the winding needle 100 winding the electrode sheet, m is the current number of turns of the winding needle, J is the thickness calculation coefficient, with a value range of 0.3-0.4, K is the compensation coefficient, with a value range of 1.5-16, and λ is the compensation constant, with a value range of 0.003-0.007.

[0038] After calculating the pressure adjustment value F, the sign of the actual deviation value ΔΦ determines whether the pressure of the shaping roller 400 should be increased or decreased. Specifically, when ΔΦ is negative, the actual angle Φ is less than the target preset angle value Am, indicating that the outer diameter of the electrode 200 wound by the winding needle 100 is too large, resulting in a smaller angle rotated by the winding needle 100. In this case, the thickness of the electrode 200 is too thick, so the thickness of the electrode 200 needs to be reduced, and the pressure of the shaping roller 400 needs to be reduced. When ΔΦ is positive, the actual angle Φ is greater than the target preset angle value Am, indicating that the outer diameter of the electrode 200 wound by the winding needle 100 is too small, resulting in a larger angle rotated by the winding needle 100. In this case, the thickness of the electrode 200 is too thin, so the thickness of the electrode 200 needs to be increased, and the pressure of the shaping roller 400 needs to be increased.

[0039] It should be noted that L0 is a fixed parameter of the winding equipment, which can be selected through the parameter standard of the winding equipment. The compensation coefficient K and the compensation constant λ can be selected according to the actual needs based on the compaction degree of the electrode 200.

[0040] Specifically, the compensation coefficient K can be 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, or 16. Of course, the compensation coefficient K can also be chosen from other values ​​within the range of 1.5-16, and is not limited to the examples above.

[0041] The compensation constant λ can be 0.003, 0.0031, 0.0032, 0.0033, 0.0034, 0.0035, 0.0036, 0.0037, 0.0038, 0.0039, 0.004, 0.0041, 0.0042, 0.0043, 0.0044, 0.0045, 0.0046, 0.0047, 0.0048, or 0.0049. The values ​​are: 0.005, 0.0051, 0.0052, 0.0053, 0.0054, 0.0055, 0.0056, 0.0057, 0.0058, 0.0059, 0.006, 0.0061, 0.0062, 0.0063, 0.0064, 0.0065, 0.0066, 0.0067, 0.0068, 0.0069, and 0.007. Of course, the compensation constant λ can also be chosen from other values ​​within the range of 0.003-0.007, and is not limited to the examples above.

[0042] The following table provides the specific values ​​of the preset angle A for a reference cell 500 and the actual angle Φ during the manufacturing process of the wound cell. Table 1 also provides the specific adjustment process of the pressure adjustment value F during the winding of a cell.

[0043] Table 1

[0044] Current number of turns of the winding needle Preset angle value A of the winding needle Actual angle Φ 1 363.54 363.58 2 363.49 363.5 3 363.44 363.42 4 363.39 363.34 5 363.34 363.26 6 363.29 363.18 7 363.24 363.1 8 363.19 363.02 9 363.14 362.94 10 363.09 362.86 11 363.04 362.78 12 362.99 362.7 13 362.94 362.62 14 362.89 362.54 15 362.84 362.46 16 362.79 362.38 17 362.74 362.3 18 362.69 362.22 19 362.64 362.14 20 362.59 362.06 21 362.54 361.98 22 362.49 361.9 23 362.44 361.82 24 362.39 361.74 25 362.34 361.66

[0045] It should be further explained that when detecting the angle rotated by the winding needle 100, the initial trigger angle of the winding needle 100 is zeroed. That is, after the tab detection device 300 detects the first tab 201 and records the angle rotated by the winding needle 100, the counting angle continues to accumulate and record the angle rotated by the winding needle 100 when the second tab 201 is detected. Refer to Table 1 for specific calculations of the pressure adjustment value F of the shaping roller 400.

[0046] The preset deviation value E is set to 0.5°. When the absolute value of the actual deviation value ΔΦ between the actual angle Φ and the preset angle value A exceeds 0.5°, it is determined that the tab 201 has deviated and the thickness of the electrode 200 needs to be adjusted.

[0047] The formulas for calculating the set pressure adjustment value F and the actual deviation value ΔΦ are as follows:

[0048] F=(((L0 / 360)*(ΔΦ / m)) / J)*K+λ

[0049] Where: L0 = 268mm, thickness calculation coefficient J is 0.38, compensation coefficient K is 7, and compensation constant λ is 0.0053.

[0050] Referring to Table 1, when the current winding number of the needle is 20, the preset angle value A is 362.59°, the actual angle Φ is 362.06°, and the actual deviation value ΔΦ is -0.53°. Substituting these values ​​into the formula, we can obtain F = -0.0474 MPa. This indicates that the pressure of the shaping roller 400 on the electrode 200 needs to be reduced at this time. That is, when the needle 100 is winding for the 21st time, the pressure of the shaping roller 400 needs to be reduced by 0.0474 MPa.

[0051] When the current winding number of the needle is 25, the preset angle value A is 362.34°, the actual angle Φ is 361.66°, and the actual deviation value ΔΦ is -0.68°. Substituting these values ​​into the formula, we can obtain F = -0.043 MPa. This indicates that the pressure of the shaping roller 400 on the electrode 200 needs to be reduced at this time. The initial pressure of the shaping roller 400 is set to 0.15 MPa. Therefore, when the needle 100 winds for the 26th time, the pressure of the shaping roller 400 needs to be reduced by 0.043 MPa.

[0052] refer to Figure 2 As shown, in the process of manufacturing the wound battery cell, in addition to the positive electrode 210 and the negative electrode 220, an upper separator 700 and a lower separator 800 are also required. Therefore, in other embodiments of the present invention, the preset condition can also be the angle through which the winding needle 100 rotates when the positive electrode 210, the negative electrode 220, the upper separator 700, and the lower separator 800 output a specified length, and is not limited to the description above of the preset condition being the detection of one of the tabs 201 in the tab group.

[0053] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0054] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A pole piece winding method characterized by, Includes the following steps: In response to the fulfillment of preset conditions, the angle through which the winding needle has rotated is detected and set as the actual angle Φ; Based on the preset angle data, calculate the actual deviation value ΔΦ corresponding to the actual angle Φ; The absolute value of the actual deviation value ΔΦ is compared with the preset deviation value E. If the absolute value of the actual deviation value ΔΦ exceeds the preset deviation value E, the thickness of the electrode is adjusted according to the actual deviation value ΔΦ in order to wind the electrode. The preset angle data includes at least one preset angle value A, and each preset angle value A has a corresponding number of winding turns of the coil needle; The actual angle Φ corresponds to the current number of turns m of the winding needle. Calculating the actual deviation value ΔΦ corresponding to the actual angle Φ includes: Based on the preset angle data, obtain the target preset angle value Am corresponding to the current number of winding turns m of the winding needle, and calculate the difference between the actual angle Φ and the target preset angle value Am to obtain the actual deviation value ΔΦ. The step of adjusting the thickness of the electrode sheet according to the actual deviation value ΔΦ includes: The pressure adjustment value F is calculated based on the actual deviation value ΔΦ. The pressure adjustment value F is used to correct the pressure applied to the electrode by the forming roller, so as to adjust the thickness of the electrode. The actual deviation value ΔΦ and the pressure adjustment value F satisfy the following relationship: F=(((L0 / 360)*(ΔΦ / m))*J)*K+λ; where: L0 is the initial circumference of the winding needle for winding the electrode sheet, m is the current number of turns of the winding needle, J is the thickness calculation coefficient, with a value range of 0.3-0.4, K is the compensation coefficient, with a value range of 1.5-16, and λ is the compensation constant, with a value range of 0.003-0.

007.

2. The pole piece winding method according to claim 1, characterized by, The electrode sheet is provided with a tab group, and each tab group includes multiple tabs. The preset condition includes detecting one of the tabs in the tab group.

3. The pole piece winding method according to claim 2, characterized by, The electrode includes a positive electrode and a negative electrode, the electrode tab group includes a positive electrode tab group and a negative electrode tab group, and the preset condition includes detecting multiple positive electrodes in the positive electrode tab group and / or detecting multiple negative electrodes in the negative electrode tab group.

4. The pole piece winding method according to claim 3, characterized by, When the positive electrode tab is detected, the difference between the first angle Φ1 rotated by the winding needle and the preset angle value A is the first difference value; when the negative electrode tab is detected, the difference between the second angle Φ2 rotated by the winding needle and the preset angle value A is the second difference value; wherein, The actual deviation value ΔΦ is the first difference; or... The actual deviation value ΔΦ is the second difference; or... The actual deviation value ΔΦ is the average of the first difference and the second difference.

5. The pole piece winding method according to claim 3, characterized by, The preset condition is a preset time delay after the electrode is detected.

6. The pole piece winding method according to claim 1, characterized by, The preset deviation value E is 0.05°-0.5°.

7. The electrode winding method according to claim 1, characterized in that, A battery cell with a tab deviation δ less than a preset deviation δ0 is used as a reference battery cell; wherein: during the winding of the reference battery cell, in response to the satisfaction of a preset condition, the angle through which the winding needle rotates is detected and set as the preset angle data.

8. The electrode winding method according to claim 7, characterized in that, The range of the preset deviation δ0 is 0.5mm-10mm.

9. The electrode winding method according to claim 8, characterized in that, Also includes: Each time a cell is wound, the tab deviation δ of the cell is detected. When the tab deviation δ of the newly wound cell is less than the tab deviation δ of the reference cell, the original reference cell is replaced with the newly wound cell, and the preset angle data is determined using the newly wound cell.

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