Pole piece winding method

Abstract

The invention belongs to the technical field of battery manufacturing, and discloses a pole piece winding method, which comprises the following steps: detecting the rotating angle of a winding needle in response to meeting a preset condition, and setting the rotating angle as an actual angle phi; calculating an actual deviation value delta phi corresponding to the actual angle phi according to preset angle data; the absolute value of the actual deviation value delta phi is compared with a preset deviation value E, and under the condition that the absolute value of the actual deviation value delta phi exceeds the preset deviation value E, the thickness of the pole piece is adjusted according to the actual deviation value delta phi so as to wind the pole piece. By adopting the method, the alignment degree condition of the tabs is monitored in real time in the winding process, the alignment degree of the tabs is automatically adjusted according to the dislocation amount of the tabs, the adjusting precision is improved, and the rejection rate is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of battery manufacturing, and in particular to a pole piece winding method. Background Art

[0002] As the length of the pole piece and the number of pole lugs of existing wound cells increase, the requirements for the consistency of the pole piece thickness become increasingly higher. When the pole piece thickness fluctuates, it will cause the pole lugs to be misaligned during the winding process, thereby increasing the manufacturing scrap rate of the wound battery cell.

[0003] In order to improve the phenomenon of tab misalignment, the conventional method is to correct the Teflon position on the winding needle or use a variable diameter winding needle to adjust the tab alignment, but this method often has a certain lag and cannot detect the tab misalignment in time and adjust it in time. In actual application, it is often necessary to adjust after several consecutive battery cells are misaligned, and the amount of adjustment depends on the operator's work experience. It is impossible to ensure that the adjustment is in place at one time, which may produce more waste.

[0004] Therefore, it is urgent to propose a method that can monitor the alignment of the pole lugs in real time during the winding process and automatically adjust the alignment of the pole lugs according to the misalignment of the pole lugs. Summary of the invention

[0005] The object of the present invention is to provide a pole piece winding method, which adopts the method to monitor the alignment of the pole lugs in real time during the winding process and automatically adjust the thickness of the pole piece according to the misalignment of the pole lugs, thereby ensuring the alignment of the pole lugs and reducing the scrap rate.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] The present invention discloses a pole piece winding method, comprising the following steps: in response to satisfying a preset condition, detecting the angle through which a winding needle has rotated, and setting it as an actual angle Φ; calculating an actual deviation value ΔΦ corresponding to the actual angle Φ according to preset angle data; comparing the absolute value of the actual deviation value ΔΦ with a preset deviation value E, and when 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.

[0008] The beneficial effect of a pole piece winding method of the present invention is as follows: in the method provided by the present invention, in response to satisfying a preset condition, the angle of rotation of the winding needle is detected and set as the actual angle Φ; then, according to 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 pole ear has a deviation. And after the deviation of the pole ear is detected, the thickness of the pole piece can be adjusted according to the actual deviation value ΔΦ, and the misalignment of the pole ear during the winding process can be compensated, and the alignment of the pole ear can be monitored in real time during the winding process and the alignment of the pole ear can be automatically adjusted according to the misalignment of the pole ear, so as to improve the adjustment accuracy and reduce the scrap rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic flow chart of a pole piece winding method according to an embodiment of the present invention;

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

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

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

[0013] Figure 5 Schematic diagram of the structure of the pole piece of the embodiment of the present invention.

[0014] Reference numerals:

[0015] 100, winding needle; 200, pole piece; 210, positive pole piece; 220, negative pole piece; 201, pole tab; 300, pole tab detection device; 400, shaping roller; 500, reference battery cell; 600, deviation battery cell; 700, upper diaphragm; 800, lower diaphragm. DETAILED DESCRIPTION

[0016] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific circumstances. In the description of the present embodiment, the terms "upper", "lower", "left", "right", "front", "back" and other directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention.

[0017] The present invention discloses a pole piece winding method, referring to Figure 1 As shown, the pole piece winding method includes the following steps: S1: in response to satisfying a preset condition, detecting the angle through which the winding needle 100 has rotated, and setting it as the actual angle Φ; S2: calculating the actual deviation value ΔΦ corresponding to the actual angle Φ according to the preset angle data; S3: comparing the absolute value of the actual deviation value ΔΦ with the preset deviation value E, and when the absolute value of the actual deviation value ΔΦ exceeds the preset deviation value E, adjusting the thickness of the pole piece 200 according to the actual deviation value ΔΦ to wind the pole piece 200.

[0018] First of all, it should be noted that in the actual winding process, a pole lug group is provided on the pole piece 200. Since the die-cutting parameters are the same for each EA, refer to Figure 5 As shown, the spacing between the multiple pole ears 201 in the pole ear group on the pole piece 200 gradually increases. If the thickness of the pole piece 200 is always a constant value, then during the winding process, the pole ears 201 of the two adjacent layers are basically arranged opposite each other, and no deviation will occur. However, due to manufacturing reasons, the thickness of the pole piece 200 will not remain completely consistent. In this case, during the winding process, deviations will occur between the pole ears 201 of the two adjacent layers. It can be understood that in the pole piece winding method provided by the present invention, in response to meeting a preset condition, the angle through which the winding needle 100 has rotated is detected and set to the actual angle Φ; according to 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 pole ear 201 of the battery cell has deviated (reference Figure 4 As shown, Figure 4The deviation cell 600 shown in FIG. 6 shows a deviation of the tab 201. The tab 201 of the cell needs to be corrected, and the thickness of the pole piece 200 can be adjusted according to the actual deviation value ΔΦ during the correction process to wind the pole piece 200 so as to achieve the purpose of correcting the alignment of the tab. When the absolute value of the actual deviation value ΔΦ is less than the preset deviation value E, it means that the alignment of the tab 201 of the cell is good at this time, and it can be determined that the tab 201 of the cell does not deviate and does not need to be corrected.

[0019] In summary, the pole piece winding method provided by the present invention realizes real-time monitoring of the pole ear alignment during the winding process, and can automatically adjust the pole ear alignment according to the misalignment of the pole ear 201, thereby improving the adjustment accuracy and reducing the scrap rate. In addition, the detection condition is triggered by the pole ear position, and the angle value obtained by the detection is more in line with the actual situation of the battery cell, which can better ensure the pole ear 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°, 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 above examples. It can be understood that the smaller the preset deviation value E is set, the more times the thickness of the pole piece 200 is adjusted, and the better the alignment of the pole lugs of the wound battery cell, but the lower the efficiency, and the larger the preset deviation value E is set, the fewer times the thickness of the pole piece 200 is adjusted, and the worse the alignment of the pole lugs of the wound battery cell, but the higher the efficiency. In the actual operation process, it is necessary to comprehensively consider the production requirements of the pole lug alignment and the production efficiency to design, so that the pole lug alignment of the wound battery cell is better and the production efficiency is also higher.

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

[0022] In step S1, the preset conditions include detecting the pole lug on the pole piece 200, specifically, referring to Figure 5 As shown, a plurality of tab groups are arranged on the pole piece 200, and each tab group includes a plurality of tabs 201. The preset condition is that one tab 201 in the tab group is detected. It can be understood that in the actual winding process, the pole piece raw material roll is continuously output, and the winding needle 100 is continuously rotated. The tab 201 is detected by the tab detection device 300 arranged on the winding device, and is used as the preset condition. Since the tab 201 has a certain width, the reference 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 the preset condition facilitates the execution logic of the design method on the one hand, and on the other hand, the modification of the winding equipment is relatively small, which is convenient for implementation.

[0023] It should be noted that, since the electrode sheet 200 includes a positive electrode sheet 210 and a negative electrode sheet 220, and the electrode tab group includes a positive electrode tab group and a negative electrode tab group, the preset condition includes detecting multiple positive electrode tabs in the positive electrode tab group and / or detecting multiple negative electrode tabs in the negative electrode tab group. In actual operation, the detection of positive electrode tabs and / or negative electrode tabs can be used as preset conditions. In either case, the principle of adjusting the thickness of the electrode sheet 200 according to the actual deviation value ΔΦ is the same. The only difference is that the meaning represented by the actual deviation value ΔΦ is different and the specific adjustment type of the electrode sheet 200 is different, as follows:

[0024] The preset condition is that when the positive electrode tab in the positive electrode tab group is detected, the angle rotated by the winding needle 100 is set to the actual angle Φ positive, and 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 ear in the negative electrode ear group is detected, the angle rotated by the winding needle 100 is set to the actual angle Φ negative, and 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 ear in a positive electrode ear is detected, and a negative electrode ear in a negative electrode ear group is detected, then an actual angle Φ positive and an actual angle Φ negative are obtained. At this time, the difference between the actual angle Φ positive and the preset angle value A is set as a first difference, and the difference between the actual angle Φ negative and the preset angle value A is set as a second difference. The actual deviation value ΔΦ is the average of the first difference and the second difference. At this time, the thickness of the positive electrode sheet 210 can be adjusted only, the thickness of the negative electrode sheet 220 can be adjusted only, or the thickness of the positive electrode sheet 210 and the negative electrode sheet 220 can be adjusted simultaneously according to the actual deviation value ΔΦ.

[0027] It should be noted that, in this case, a tab detection device 300 is provided on both the transported positive electrode sheet 210 and the negative electrode sheet 220, and they are respectively configured as a positive tab detection device and a negative tab detection device. The situation in which the preset conditions are met may be that the positive tab detection device detects the positive tab and the negative tab detection device detects the negative tab at the same time, or that the positive tab detection device first detects the i-th positive tab in the positive tab group, and then the negative tab detection device first detects the i-th negative tab in the negative tab group. After the i-th negative tab is detected, the actual deviation value ΔΦ is obtained based on the actual angle Φpositive and the actual angle Φnegative.

[0028] Optionally, the preset condition is to delay the preset time after the pole tab 201 is detected. It is understandable that during the actual production and transportation of the pole piece raw material roll, there may be foreign matter or other manufacturing deviation structures on the pole piece 200, and these structures will interfere with the detection accuracy of the pole piece detection device 300. The preset condition is to delay the preset time after the pole tab 201 is detected. That is to say, in the actual working process, the time point when the pole tab detection device 300 just detects the pole tab 201 is T0, but the time point when the winding needle 100 turns the angle is recorded is T1, and T1 is the time point of T0+preset time. This method of delaying the time when the winding needle 100 turns the angle can ensure that the time point when the winding needle 100 turns the angle must be the time when the pole tab detection device 300 detects the pole tab 201, rather than the time of the interference, which is conducive to improving the accuracy of recording the angle when the winding needle 100 turns, and obtaining a more accurate actual angle Φ, so as to achieve a more accurate adjustment of the thickness of the pole piece 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, in the batch production process, the battery cells produced by winding will be quality inspected, and the battery cells in a batch with the tab deviation δ less than the preset deviation δ0 are used as the reference battery cells 500 ( Figure 3 The battery cell shown in the figure), then the angle through which the winding needle 100 rotates when detecting multiple pole lugs 201 in sequence when winding this reference battery cell 500 is used as the preset angle value A, and the preset angle data is set to an array according to the number of winding turns of the winding needle during the detection process, that is, when manufacturing the reference battery cell 500, when the pole lug detection device 300 senses the first pole lug 201, the second pole lug 201, the third pole lug 201...the Nth pole lug 201, the angle detection device on the winding needle 100 will detect N angle values, and according to the number of winding turns of the winding needle 100, a standard array {A1, A2, A3...AN} including N preset angle values ​​A can be stored in the control system of the winding device at this time, and this standard array is used as the preset angle data in step S2.

[0030] After the preset angle data is determined, in the subsequent production process of the battery cell, when the pole ear detection device 300 senses the first pole ear 201, the second pole ear 201, the third pole ear 201...the Nth pole ear 201, the angle detection device on the winding needle 100 will also be able to obtain N angle values. According to the number of turns wound by the winding needle 100, a detection array {Φ1, Φ2, Φ3...ΦN} is obtained in turn. Each value in the detection array is an actual angle Φ, and each actual angle Φ will have a corresponding number of turns m currently wound by the winding needle (for example, Φ1 represents the actual angle when the current number of turns wound by the winding needle is 1).

[0031] According to the foregoing, the actual deviation value ΔΦ corresponding to the actual angle Φ is calculated, including: obtaining the target preset angle value Am corresponding to the current winding number m of the winding needle according to the 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 to ΔΦ1. If the absolute value of ΔΦ1 is larger than the preset deviation value E, it means that when the second pole ear 201 is detected, the pole ear 201 has already had a deviation. Specifically, if ΔΦ1 is a negative value, it means that the thickness of the pole piece 200 is too large, and the thickness of the pole piece 200 needs to be reduced in the subsequent time period. If ΔΦ1 is a positive value, it means that the thickness of the pole piece 200 is too small, and the thickness of the pole piece 200 needs to be increased in the subsequent time period, thereby adjusting the alignment of the pole ear, avoiding the pole ear alignment being scrapped, and improving the quality 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, 10mm. Of course, the tab deviation δ can also be selected from other data within the range of 0.5mm-10mm according to actual conditions, and is not limited to the above examples. It should be noted that the size of the preset deviation δ0 needs to be determined according to the actual production requirements of the wound battery cell. If the preset deviation δ0 is too large, the scrap rate will increase. If the preset deviation δ0 is too small, the thickness of the electrode 200 will be adjusted too many times during the winding process, affecting the normal production efficiency. In this embodiment, the range of the preset deviation δ0 is controlled within 0.5mm-10mm, which can not only ensure the production yield and reduce the number of unqualified products (products with excessively large ear deviation δ), but also control the number of thickness adjustments of the electrode 200 to ensure production efficiency.

[0033] Optionally, each time a battery cell is wound, the tab deviation δ of the battery cell is detected. When the tab deviation δ of the newly wound battery cell is less than the tab deviation δ of the reference battery cell 500, the newly wound battery cell replaces the original reference battery cell 500, and the preset angle value A is determined by the newly wound battery cell. It can be understood that in the actual manufacturing process, each time a battery cell is wound, the tab alignment of the newly wound battery cell may be better than the previously determined reference battery cell 500, or may be worse than the previously determined reference battery cell 500. In the process of implementing the method, the tab 201 of the newly wound battery cell is compared with the original reference battery cell 500, and then the reference battery cell 500 is updated in real time, so that the tab alignment of each subsequent wound battery cell can be maximized, thereby improving the manufacturing yield of the battery cell.

[0034] In step S3, the thickness of the pole piece 200 is adjusted according to the actual deviation value ΔΦ, including: calculating a pressure adjustment value F according to the actual deviation value ΔΦ, and the pressure adjustment value F is used to correct the pressure applied by the shaping roller 400 to the pole piece 200 to adjust the thickness of the pole piece 200. It can be understood that the thickness of the pole piece 200 is adjusted by adjusting the pressure of the shaping roller 400 on the pole piece 200, which, on the one hand, facilitates the execution logic of the design method, and on the other hand, requires less modification to the winding equipment, which is convenient for implementation.

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

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

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

[0038] After the pressure adjustment value F is calculated, the pressure of the shaping roller 400 is judged to be increased or decreased based on the positive or negative sign of the actual deviation value ΔΦ. Specifically, when ΔΦ is a negative value, the actual angle Φ is less than the target preset angle value Am, indicating that the outer diameter of the pole piece 200 wound by the winding needle 100 is too large, resulting in a small angle through which the winding needle 100 rotates. At this time, the thickness of the pole piece 200 is too thick, and it is necessary to reduce the thickness of the pole piece 200 and reduce the pressure of the shaping roller 400. When ΔΦ is a positive value, the actual angle Φ is greater than the target preset angle value Am, indicating that the outer diameter of the pole piece 200 wound by the winding needle 100 is too small, resulting in a large angle through which the winding needle 100 rotates. At this time, the thickness of the pole piece 200 is too thin, and it is necessary to increase the thickness of the pole piece 200 and increase the pressure of the shaping roller 400.

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

[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, 16. Of course, the compensation coefficient K can also select other values ​​within the range of 1.5-16, and is not limited to the above examples.

[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, 0.0049 Of course, the compensation constant λ may also be selected from other values ​​within the range of 0.003-0.007, and is not limited to the above examples.

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

[0043] Table 1

[0044] Current winding number of the winding needle Preset angle value A of 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 noted that when detecting the angle of the winding needle 100, the angle of the winding needle 100 is initially triggered to return to zero, that is, after the tab detection device 300 detects the first tab 201 and records the angle of the winding needle 100, the counting angle accumulation continues to record the angle of the winding needle 100 when the second tab 201 is detected. Referring to Table 1, the pressure adjustment value F of the shaping roller 400 is specifically calculated.

[0046] The preset deviation value E is set to 0.5°, that is, 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 pole ear 201 has deviated and the thickness of the pole piece 200 needs to be adjusted.

[0047] The calculation formula for the set pressure adjustment value F and the actual deviation value ΔΦ is as follows:

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

[0049] Wherein: 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 number of winding turns of the winding 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 into the formula, we can get F=-0.0474Mpa, which means that it is necessary to reduce the pressure of the shaping roller 400 on the pole piece 200 at this time, that is, when the winding needle 100 is wound for the 21st turn, the pressure of the shaping roller 400 needs to be reduced by 0.0474Mpa.

[0051] When the current number of winding turns of the winding 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 into the formula, we can get F=-0.043Mpa, which means that it is necessary to reduce the pressure of the shaping roller 400 on the pole piece 200 at this time. The initial pressure of the shaping roller 400 is set to 0.15Mpa. When the winding needle 100 is wound for the 26th turn, that is, when the winding needle 100 is wound for the 26th turn, the pressure of the shaping roller 400 needs to be reduced by 0.043Mpa.

[0052] refer to Figure 2 As shown, in the process of winding the battery cell manufacturing, in addition to the positive electrode sheet 210 and the negative electrode sheet 220, the upper separator 700 and the 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 sheet 210, the negative electrode sheet 220, the upper separator 700, and the lower separator 800 output a specified length, and is not limited to the description of the setting condition as described above that one of the tabs 201 in the tab group is detected.

[0053] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[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 embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A pole piece winding method, characterized in that: The steps include: In response to the preset condition being met, the angle through which the winding needle has rotated is detected and set as the actual angle Φ; Calculate the actual deviation value ΔΦ corresponding to the actual angle Φ according to the preset angle data; 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, the thickness of the pole piece is adjusted according to the actual deviation value ΔΦ to wind the pole piece.

2. The pole piece winding method according to claim 1, characterized in that: 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.

3. The pole piece winding method according to claim 2, characterized in that: The actual angle Φ corresponds to the current winding number m of the winding needle; Calculating the actual deviation value ΔΦ corresponding to the actual angle Φ includes: According to the preset angle data, the target preset angle value Am corresponding to the current winding number m of the winding needle is obtained, and the difference between the actual angle Φ and the target preset angle value Am is calculated to obtain the actual deviation value ΔΦ.

4. The pole piece winding method according to claim 1, characterized in that: The adjusting the thickness of the pole piece according to the actual deviation value ΔΦ comprises: A pressure adjustment value F is calculated according to the actual deviation value ΔΦ, and the pressure adjustment value F is used to correct the pressure applied by the shaping roller to the pole piece to adjust the thickness of the pole piece.

5. The pole piece winding method according to claim 4, characterized in that: The actual deviation value ΔΦ and the pressure adjustment value F satisfy the relationship: F=(((L0 / 360)*(ΔΦ / m))*J)*K+λ; where: L0 is the initial circumference of the winding needle for winding the pole piece, m is the current number of winding turns of the winding needle, J is the thickness calculation coefficient, ranging from 0.3 to 0.4, K is the compensation coefficient, ranging from 1.5 to 16, and λ is the compensation constant, ranging from 0.003 to 0.

007.

6. The pole piece winding method according to claim 1, characterized in that: A pole lug group is arranged on the pole piece, each of the pole lug groups includes a plurality of pole lugs, and the preset condition includes detecting one of the pole lugs in the pole lug group.

7. The pole piece winding method according to claim 6, characterized in that: The electrode sheets include positive electrode sheets and negative electrode sheets, the electrode tab groups include positive electrode tab groups and negative electrode tab groups, and the preset conditions include detecting a plurality of positive electrode tabs in the positive electrode tab group and / or detecting a plurality of negative electrode tabs in the negative electrode tab group.

8. The pole piece winding method according to claim 7, characterized in that: When the positive electrode ear is detected, the difference between the first angle Φ1 rotated by the winding needle and the preset angle value A is a first difference, and when the negative electrode ear is detected, the difference between the first angle Φ2 rotated by the winding needle and the preset angle value A is a second difference; 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.

9. The pole piece winding method according to claim 6, characterized in that: The preset condition is to delay for a preset period of time after the pole ear is detected.

10. The pole piece winding method according to claim 1, characterized in that: The preset deviation value E is: 0.05°-0.5°.

11. The pole piece winding method according to any one of claims 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: in the process of winding the reference battery cell, in response to meeting a preset condition, the angle through which the winding needle has rotated is detected and set as the preset angle data.

12. The pole piece winding method according to claim 11, characterized in that: The range of the preset deviation δ0 is: 0.5mm-10mm.

13. The pole piece winding method according to claim 11, characterized in that: Also includes: Each time a battery cell is wound, the tab deviation δ of the battery cell is detected. When the tab deviation δ of the newly wound battery cell is less than the tab deviation δ of the reference battery cell, the newly wound battery cell replaces the original reference battery cell, and the preset angle data is determined using the newly wound battery cell.

Images