Manufacturing method of wound battery cell

Abstract

The invention belongs to the technical field of battery manufacturing, and discloses a winding battery cell manufacturing method, which comprises the following steps: setting the output length of a raw material meeting a specified condition as a detection value X; according to the specified length data, calculating a length deviation value delta L corresponding to the detection value X, and if the absolute value of the length deviation value delta L exceeds a preset threshold value delta L0, judging that the tab has deviation; and when the tab has deviation, adjusting the thickness of the pole piece according to the length deviation value delta L so as to carry out subsequent winding of the battery cell. 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 deviation value 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 method for manufacturing a wound battery cell. Background Art

[0002] With the increase of pole piece length and the increase of pole lug number in existing battery cells, the consistency of pole piece thickness is required to be higher and higher. When the pole piece thickness fluctuates, it will cause the pole lug misalignment during the winding process, thereby increasing the manufacturing scrap rate of the battery cell. In order to improve the phenomenon of pole lug misalignment, the conventional method is to correct the Teflon position on the winding needle or use a variable diameter winding needle to adjust the pole lug alignment, but this method often has a certain lag, and the pole lug misalignment cannot be detected and adjusted 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 work experience of the operator. It cannot be ensured that the adjustment is in place at one time, which may produce more scrap. 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 deviation of the pole lugs. Summary of the invention

[0003] The object of the present invention is to provide a method for manufacturing a wound battery cell, by which the alignment of the pole tabs can be monitored in real time during the winding process and the alignment of the pole tabs can be automatically adjusted according to the deviation of the pole tabs, thereby improving the adjustment accuracy and reducing the scrap rate.

[0004] To achieve this object, the present invention adopts the following technical solutions:

[0005] The present invention discloses a method for manufacturing a wound battery cell, comprising the following steps: in response to meeting a specified condition, measuring the length of a raw material and setting it as a detection value X; calculating a length deviation value ΔL corresponding to the detection value X according to the specified length data, and determining that a deviation occurs in a pole ear when the absolute value of the length deviation value ΔL exceeds a preset threshold value ΔL0; when a deviation occurs in the pole ear, adjusting the thickness of the pole sheet according to the length deviation value ΔL to perform subsequent winding of the battery cell.

[0006] The winding cell manufacturing method disclosed in the present invention has the following beneficial effects: In the method provided by the present invention, the raw material output length in response to meeting the specified conditions is set as the detection value X; by calculating the absolute value of the length deviation value ΔL corresponding to the detection value X and the preset threshold value ΔL0, when the absolute value of the length deviation value ΔL is greater than the preset threshold value ΔL0, it is determined that the tab has a deviation. When the tab is detected to have a deviation, the thickness of the pole piece can be adjusted according to the length deviation value ΔL to achieve compensation for the tab misalignment during the winding process, and the tab alignment is monitored in real time during the winding process and the tab alignment is automatically adjusted according to the tab deviation, thereby improving the adjustment accuracy and reducing the scrap rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 1 is a schematic diagram of a process for manufacturing a wound battery cell according to an embodiment of the present invention;

[0008] Figure 2 is a schematic diagram of the structure of the winding device;

[0009] Figure 3 is a schematic structural diagram of a standard battery cell according to an embodiment of the present invention;

[0010] Figure 4 Schematic diagram of the structure of the deviation cell according to an embodiment of the present invention.

[0011] Reference numerals:

[0012] 100, winding needle; 200, positive electrode sheet; 300, negative electrode sheet; 400, upper diaphragm; 500, lower diaphragm; 600, length measuring roller; 700, electrode sheet shaping roller; 800, reference battery cell; 900, deviation battery cell. DETAILED DESCRIPTION

[0013] 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 part of the present invention, rather than all of the structures, are shown in the accompanying drawings. In the description of the present invention, 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, and are 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.

[0014] The present invention discloses a method for manufacturing a wound battery core, referring to Figure 1 As shown, the method for manufacturing a wound battery cell includes the following steps: S1: in response to meeting a specified condition, measuring the length of the raw material and setting it as a detection value X; S2: calculating the length deviation value ΔL corresponding to the detection value X according to the specified length data, and when the absolute value of the length deviation value ΔL exceeds the preset threshold value ΔL0, determining that the pole ear has a deviation; S3: when the pole ear has a deviation, adjusting the thickness of the pole sheet according to the length deviation value ΔL to perform subsequent winding of the battery cell.

[0015] First of all, it should be noted that in the actual winding process, if the thickness of the raw material is always a constant value, then during the winding process, the tabs of the two adjacent layers are basically set opposite to each other and there will be no deviation. However, due to manufacturing reasons, the thickness of the raw material will not be completely consistent. In this case, during the winding process, the tabs of the two adjacent layers will deviate.

[0016] It can be understood that in the wound cell manufacturing method provided by the present invention, the raw material output length in response to meeting the specified conditions can be set to the detection value X; by calculating the absolute value of the length deviation value ΔL corresponding to the detection value X and the preset threshold value ΔL0, when the absolute value of the length deviation value ΔL is greater than or equal to the preset threshold value ΔL0, it is determined that the tab has a deviation (reference Figure 4 As shown, Figure 4 Shown in the figure is a deviation battery cell 900 in which the pole ear has deviation). When the deviation of the pole ear is detected, the thickness of the pole sheet can be adjusted according to the length deviation value ΔL to compensate for the misalignment of the pole ear during the winding process, 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 deviation of the pole ear, thereby improving the adjustment accuracy and reducing the scrap rate. When the absolute value of the length deviation value ΔL is less than the preset threshold value ΔL0, it is determined that there is no deviation in the pole ear and no correction is required. Therefore, the winding battery cell manufacturing method provided by the present invention realizes the real-time monitoring of the alignment of the pole ear during the battery cell manufacturing process, and can automatically adjust the alignment of the pole ear according to the deviation of the pole ear 201, thereby improving the adjustment accuracy and reducing the scrap rate, and there is no need to use additional sensors, and the trigger condition can be set directly through the winding needle 100 of the winding battery cell, and the trigger condition is convenient to set. It should be supplemented that, referring to Figure 2 As shown, in the manufacturing process of the battery cell, the raw materials to be used include the positive electrode sheet 200, the negative electrode sheet 300, the upper diaphragm 400 and the lower diaphragm 500. The raw material in the embodiment of the present invention can be any one of the positive electrode sheet 200, the negative electrode sheet 300, the upper diaphragm 400 and the lower diaphragm 500. At this time, the detection value X is any one of the length detection values ​​of the positive electrode sheet 200, the negative electrode sheet 300, the upper diaphragm 400 and the lower diaphragm 500. The raw material in the embodiment of the present invention can also be at least two of the positive electrode sheet 200, the negative electrode sheet 300, the upper diaphragm 400 and the lower diaphragm 500, and the values ​​of the length of the raw material include X positive, X negative, X upper, and X lower, and the detection value X is the average value of the length of the raw material.

[0017] In actual operation, no matter which of the above situations is used, the principle of adjusting the thickness of the pole piece according to the length deviation value ΔL is the same. The only difference is that the meaning represented by the length deviation value ΔL is different and the specific type of adjustment pole piece is different, as follows:

[0018] If the length detection value of the positive electrode sheet 200 is used as the detection value X, then during adjustment, the thickness of the positive electrode sheet 200 is adjusted; if the length detection value of the negative electrode sheet 300 is used as the detection value X, then during adjustment, the thickness of the negative electrode sheet 300 is adjusted.

[0019] If the detected values ​​of the lengths of the upper separator 400 and the lower separator 500 are used as the detected value X, the thickness of the positive electrode sheet 200 and / or the negative electrode sheet 300 is adjusted during the adjustment.

[0020] If the detection value X is the average of the length detection values ​​of the positive electrode sheet 200 and the lower diaphragm 500 (i.e., the average of Xpositive and Xlower), the average of the length detection values ​​of the positive electrode sheet 200 and the upper diaphragm 400 (i.e., the average of Xpositive and Xupper), or the average of the length detection values ​​of the positive electrode sheet 200, the upper diaphragm 400 and the lower diaphragm 500 (i.e., the average of Xpositive, Xupper, and Xlower), the thickness of the positive electrode sheet 200 is adjusted.

[0021] If the detection value X is the average of the length detection values ​​of the negative electrode sheet 300 and the lower diaphragm 500 (i.e., the average of Xneg and Xdown), the average of the length detection values ​​of the negative electrode sheet 300 and the upper diaphragm 400 (i.e., the average of Xneg and Xup), or the average of the length detection values ​​of the negative electrode sheet 300, the upper diaphragm 400 and the lower diaphragm 500 (i.e., the average of Xneg, Xup, and Xdown), the thickness of the negative electrode sheet 300 is adjusted.

[0022] If the detection value X is the average of the length detection values ​​of the positive electrode sheet 200, the negative electrode sheet 300 and the lower diaphragm 500 (i.e., the average of Xpositive, Xnegative, and Xlower), the average of the length detection values ​​of the positive electrode sheet 200, the negative electrode sheet 300, and the upper diaphragm 400 (i.e., the average of Xpositive, Xnegative, and Xup), or the average of the length detection values ​​of the positive electrode sheet 200, the negative electrode sheet 300, the upper diaphragm 400, and the lower diaphragm 500 (i.e., the average of Xpositive, Xnegative, Xup, and Xdown), then when adjusting, the thickness of the positive electrode sheet 200 and / or the negative electrode sheet 300 is adjusted.

[0023] In the following, the above steps S1 to S3 are further explained by taking the detected value X as the length of the positive electrode sheet 200 as an example.

[0024] In step S1, the specified condition is that the winding needle 100 rotates through a specified angle θ. It is understandable that in the actual winding process, the positive electrode sheet 200 is continuously output and the winding needle 100 is continuously rotated. The length measuring roller 600 provided on the output path of the positive electrode sheet 200 of the winding device can measure the length of the positive electrode sheet 200 output when the winding needle 100 rotates through the specified angle θ and use it as the detection value. Selecting the winding needle 100 rotating through the specified angle θ as the specified condition is convenient for the execution logic of the design method on the one hand, and on the other hand, the modification of the winding device is small, which is convenient for implementation.

[0025] Optionally, the specified angle θ is: 360°-3600°. Specifically, the specified angle θ can be 360°, 720°, 1080°, 1440°, 1800°, 2160°, 2520°, 2800°, 3240°, 3600°. Of course, the specified angle θ can also be other values ​​within the range of 360°-3600°, and is not limited to the above examples. For the convenience of recording, the specified angle θ may preferably be an integer multiple of 360°. It can be understood that the larger the specified angle, the more turns the winding needle 100 has made, so the thickness of the wound battery cell on the winding needle 100 will be greater, so that it is possible to detect when multi-layer tab deviation has already occurred, which is not conducive to improving the tab alignment. If the number of turns the winding needle 100 has made is small, multiple useless detections may occur, slowing down the winding rate of the battery cell. In this embodiment, the specified angle θ is controlled within the range of 360°-3600°. On the one hand, it can ensure that the deviation of the tab is quickly detected during the winding process of the battery cell, which is beneficial to improving the tab alignment of the battery cell. On the other hand, it can control the total number of detections to ensure the winding rate of the battery cell, which is beneficial to ensuring the manufacturing efficiency of the battery cell.

[0026] In step S2, the specified length data includes at least one reference length L, and each reference length L corresponds to a cumulative rotation angle of the winding needle 100. It can be understood that in the batch production process, the alignment of the tabs of the cells produced by winding will be detected. In a batch, the cells with the tab deviation λ less than the deviation threshold λ0 are used as the reference cells 800 ( Figure 3), and in the process of winding the reference battery cell 800, the raw material output length detected according to the cumulative rotation angle of the winding needle 100 is used as the designated length data. Specifically, when winding this reference battery cell 800, the length of the positive electrode sheet 200 measured when the winding needle 100 completes winding a plurality of 360° in sequence is used as the reference length L, and according to the detection process, the designated length data is set as an array according to the cumulative rotation angle of the winding needle 100. That is, when manufacturing the reference battery cell 800, the winding needle 100 rotates 360°, 720°, 1080°...i*360°, and the length-counting roller 600 will record i reference lengths L. At this time, a standard array {L1, L2, L3...Li} containing multiple reference lengths can be stored in the control system of the winding device, and this standard array is used as the designated length data in step S2, and each data in the designated length data corresponds to a cumulative rotation angle of the winding needle 100, that is, the reference length Li is the reference length corresponding to the cumulative rotation angle of the winding needle 100. After the specified length data is determined, the winding needle 100 rotates 360°, 720°, 1080°...i*360° in the subsequent winding process, and the length measuring roller 600 will record N detection values. In the actual winding process, a detection array {X1, X2, X3...Xi} can be obtained, and the detection value X is one of the multiple detection values ​​in the detection array that meet the specified conditions, and the length deviation value ΔL corresponding to the detection value X is the cumulative value of the single deviation value Δhi. The calculation formula of the single deviation value Δhi is: Δhi=reference length Li-real-time raw material output length Xi (real-time raw material output length Xi is the value in the detection array), that is, if X10 is used as the detection value X for pole piece adjustment, At this time, ΔL=Δh1+Δh2+Δh3+Δh4++Δh5+Δh6+Δh7+Δh8+Δh9+Δh10, Δh1=X1-L1, and the rest are similar. If the absolute value of ΔL is larger than the preset threshold value ΔL0, it means that when the winding needle 100 rotates for the 10th circle, the pole ear has already deviated. Specifically, if ΔL is a positive value, it means that the thickness of the pole piece is too large, and the thickness of the pole piece needs to be reduced when the winding needle 100 rotates for the 11th circle. If ΔL is a negative value, it means that the thickness of the pole piece is too small, and the thickness of the pole piece needs to be increased when the winding needle 100 rotates for the 11th circle, thereby adjusting the alignment of the pole ear, avoiding the pole ear from being scrapped due to poor alignment, and improving the quality rate.

[0027] Optionally, the deviation threshold λ0 ranges from 0.5 mm to 10 mm. Specifically, the deviation threshold λ0 can be 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm. Of course, the deviation threshold λ0 can also be selected from other data within the range of 0.5 mm to 10 mm according to actual conditions, and is not limited to the above examples. It should be noted that the size of the deviation threshold λ0 needs to be determined according to the actual production requirements of the battery cell. If the deviation threshold λ0 is too large, the scrap rate will increase. If the deviation threshold λ0 is too small, the thickness of the electrode sheet will be adjusted too many times during the winding process, affecting the normal production efficiency. In this embodiment, the range of the deviation threshold λ0 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 λ), but also control the number of thickness adjustments of the electrode sheet to ensure production efficiency.

[0028] Optionally, step S2 also includes: after manufacturing a new battery cell each time, detecting the tab deviation λ of the battery cell, when the tab deviation λ of the newly wound battery cell is less than the tab deviation λ of the reference battery cell 800, replacing the original reference battery cell 800 with the newly wound battery cell, and determining the specified length data with the newly wound battery cell. It is understandable 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 800, or may be worse than the previously determined reference battery cell 800. In the process of implementing the method, by comparing the tab of the newly wound battery cell with the original reference battery cell 800, and then updating the reference battery cell 800 in real time, it is possible to maximize the tab alignment of each subsequent wound battery cell, thereby improving the manufacturing yield of the battery cell.

[0029] In step S3, the thickness of the pole piece is adjusted according to the length deviation value ΔL, including: calculating the adjustment coefficient α according to the length deviation value ΔL, and the adjustment coefficient α is used to correct the pressure applied by the pole piece shaping roller 700 to the pole piece (the positive pole piece 200 in this embodiment) to adjust the thickness of the pole piece (the positive pole piece 200 in this embodiment). It can be understood that the adjustment of the pole piece thickness by adjusting the pressure of the pole piece shaping roller 700 on the pole piece 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.

[0030] Optionally, the length deviation value ΔL and the adjustment coefficient α satisfy the relationship: α=(((ΔL / (θ / 360)) / 6.28)*K)*Q+γ; wherein: θ is the specified angle through which the winding needle 100 rotates, K is an empirical constant, and its value range is 1-3, Q is a compensation coefficient, and its value range is 2-13.5, and γ is a compensation constant, and its value range is 0.005-0.008. The empirical constant K can be selected according to the model thickness of the pole piece, and the compensation constant Q and the compensation constant γ can be selected according to the compaction degree of the pole piece according to actual needs. The size of the adjustment coefficient α is the adjustment value of the pressure parameter of the pole piece shaping roller 700. When the length deviation value ΔL is greater than 0, the pole piece is too thick, and the pressure parameter needs to be reduced and adjusted; when the length deviation value ΔL is less than 0, the pole piece is too thin, and the pressure parameter needs to be increased and adjusted. Specifically, the empirical constant K can be 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3. Of course, the empirical constant K can also select other values ​​in the range of 1-3, and is not limited to the above examples. The compensation coefficient Q can be 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. Of course, the compensation coefficient Q can also select other values ​​in the range of 2.5-13.5, and is not limited to the above examples. The compensation constant γ can be 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, 0.007, 0.0071, 0.0072, 0.0073, 0.0074, 0.0075, 0.0076, 0.0077, 0.0078, 0.0079, 0.008. Of course, the compensation constant γ can also select other values ​​within the range of 0.005-0.008, and is not limited to the above examples.

[0031] The following refers to Table 1 for specific values ​​of a reference length L of a reference battery cell 800 and a raw material output length of the battery cell during the manufacturing process, and refers to Table 1 for a specific adjustment process of the adjustment coefficient α during the process of winding a battery cell.

[0032] Table 1

[0033] Cumulative rotation angle of winding needle Reference length L Raw material output length 360 270.401 270.414 720 272.550 272.575 1080 274.698 274.736 1400 276.846 276.897 1800 278.995 279.058 2160 281.143 281.219 2520 283.291 283.380 2880 285.439 285.541 3240 287.588 287.702 3600 289.736 289.864 3960 291.884 292.025 4320 294.003 294.186 4680 296.181 296.347 5040 298.329 298.508 5400 300.447 300.669 5760 302.626 302.830 6120 304.774 304.991 6480 306.922 307.152 6840 309.070 309.313 7200 311.219 311.474 7560 313.367 313.635 7920 315.515 315.796 8280 317.664 317.957 8640 319.812 320.118 9000 321.960 322.279

[0034] The preset threshold ΔL0 is set to 0.5, that is, when the absolute value of the length deviation ΔL corresponding to the detection value X exceeds 0.5, it is determined that the tab has a deviation and the thickness of the electrode sheet (the positive electrode sheet 200 in this embodiment) needs to be adjusted.

[0035] The length deviation value ΔL and the adjustment coefficient α satisfy the relationship:

[0036] α=(((ΔL / (θ / 360)) / 6.28)*K)*Q+γ; where:

[0037] The empirical constant K is 1, the compensation coefficient Q is 2, and the compensation constant γ is 0.078.

[0038] Referring to Table 1, if in step S1, the specified condition is that the winding needle 100 rotates through the specified angle θ, and θ is 3600°, the reference length L is 289.736, and the detection value X is 289.864. According to calculation, it can be concluded that the length deviation value ΔL=0.7 at this time, and substituting it into the formula can obtain α=0.018Mpa, indicating that it is necessary to reduce the pressure of the pole piece shaping roller 700 on the pole piece at this time, that is, when the winding needle 100 is wound for the 11th turn, the pressure of the pole piece shaping roller 700 needs to be reduced by 0.018Mpa.

[0039] Referring to Table 1, if in step S1, the specified condition is that the winding needle 100 rotates through the specified angle θ, and θ is 7200°, the reference length L is 311.219, and the detection value X is 311.474. According to calculation, it can be concluded that the length deviation value ΔL at this time is 2.68. Substituting it into the formula, it can be obtained that α=0.12Mpa, indicating that it is necessary to reduce the pressure of the pole piece shaping roller 700 on the pole piece at this time. Therefore, when the winding needle 100 is wound for the 21st turn, the pressure of the pole piece shaping roller 700 needs to be reduced by 0.12Mpa.

[0040] Of course, in other embodiments of the present invention, the specified conditions may also be that the winding needle 100 rotates for a preset time, the raw material roll rotates for a preset angle, the raw material roll rotates for a preset time, and other conditions to adjust the alignment of the tabs. The specific conditions can be selected according to actual needs.

[0041] 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.

[0042] 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 shall be included in the protection scope of the claims of the present invention.

Claims

1. A method for manufacturing a wound battery cell, characterized in that: The steps include: Setting the raw material output length in response to satisfying the specified condition as a detection value X; According to the specified length data, a length deviation value ΔL corresponding to the detection value X is calculated. If the absolute value of the length deviation value ΔL exceeds a preset threshold value ΔL0, it is determined that a deviation occurs in the tab; When the pole ear has a deviation, the thickness of the pole piece is adjusted according to the length deviation value ΔL to perform subsequent winding of the battery cell.

2. The method for manufacturing a wound battery cell according to claim 1, characterized in that: A cell with a tab deviation λ less than a deviation threshold λ0 is used as a reference cell; wherein: in the process of winding the reference cell, the raw material output length detected according to the cumulative rotation angle of the winding needle is used as the specified length data.

3. The method for manufacturing a wound battery cell according to claim 2, characterized in that: The deviation threshold λ0 ranges from 0.5 mm to 10 mm.

4. The method for manufacturing a wound battery cell according to claim 3, characterized in that: Each time a new battery cell is manufactured, the tab deviation λ of the battery cell is detected. When the tab deviation λ of the newly wound battery cell is less than the tab deviation λ of the reference battery cell, the newly wound battery cell replaces the original reference battery cell, and the specified length data is determined using the newly wound battery cell.

5. The method for manufacturing a wound battery cell according to claim 1, characterized in that: The specified condition is that the winding needle rotates through a specified angle θ.

6. The method for manufacturing a wound battery cell according to claim 5, characterized in that: The specified angle θ is: 360°-3600°.

7. The method for manufacturing a wound battery cell according to claim 1, characterized in that: The designated length data includes at least one reference length L, and each reference length L corresponds to a cumulative rotation angle of a winding needle.

8. The method for manufacturing a wound battery cell according to claim 7, characterized in that: The detection value X corresponds to the real-time cumulative rotation angle of the winding needle, and the length deviation value ΔL is the cumulative value of the single deviation value Δhi. The calculation formula of the single deviation value Δhi is: Δhi=reference length Li-real-time raw material output length Xi; wherein: The real-time raw material output length Xi is the raw material output length corresponding to the cumulative rotation angle of the winding needle, i=a positive integer in the range of [1, j], j=the real-time cumulative rotation angle of the winding needle / 360°.

9. The method for manufacturing a wound battery cell according to claim 1, characterized in that: The length deviation value ΔL adjusts the thickness of the pole piece, including: An adjustment coefficient α is calculated according to the length deviation value ΔL, and the adjustment coefficient α is used to correct the pressure applied by the pole piece shaping roller to the pole piece to adjust the thickness of the pole piece.

10. The method for manufacturing a wound battery cell according to claim 9, characterized in that: The length deviation value ΔL and the adjustment coefficient α satisfy the relationship: α=(((ΔL / (θ / 360)) / 6.28)*K)*Q+γ; where: θ is the specified angle through which the winding needle rotates, K is an empirical constant with a value range of 1-3, Q is the compensation coefficient with a value range of 2-13.5, and γ is the compensation constant with a value range of 0.005-0.

008.

11. The method for manufacturing a wound battery cell according to claim 1, characterized in that: The raw material includes any one of a positive electrode sheet, a negative electrode sheet, an upper separator and a lower separator.

12. The method for manufacturing a wound battery cell according to claim 1, characterized in that: The raw material includes at least two of a positive electrode sheet, a negative electrode sheet, an upper diaphragm and a lower diaphragm, and the values ​​of the length of the raw material measured include X positive, X negative, X upper and X lower, and the detection value X is the average of the values ​​of the length of the raw material measured.

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