A method of manufacturing a wound cell

Abstract

The application belongs to the technical field of battery manufacturing, and discloses a winding cell manufacturing method, which comprises the following steps: setting the output length of raw materials in response to meeting specified conditions as a detection value X; calculating a length deviation value ΔL corresponding to the detection value X according to specified length data; when the absolute value of the length deviation value ΔL exceeds a preset threshold value ΔL0, determining that the tab has a deviation; when the tab has a deviation, adjusting the thickness of the pole piece according to the length deviation value ΔL to perform subsequent winding of the cell. The method can monitor the tab alignment degree in real time during winding and automatically adjust the tab alignment degree according to the deviation of the tab, thereby improving the adjustment accuracy and reducing the waste rate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery manufacturing, in particular to a winding cell manufacturing method. BACKGROUND

[0002] With the increase of the length of the pole piece and the number of the pole lug, the consistency of the thickness of the pole piece is required higher and higher. When the thickness of the pole piece fluctuates, the phenomenon of pole lug misalignment in the winding process is caused, thereby increasing the manufacturing scrap rate of the cell. In order to improve the phenomenon of pole lug misalignment, the conventional way is to correct the position of the iron fluoride on the winding needle or to use a variable diameter winding needle to adjust the alignment of the pole lug, but this way often has a certain lag and cannot timely find the misalignment of the pole lug and timely adjust. In actual application, it is often that several cells are misaligned before adjustment, and the amount of adjustment depends on the work experience of the operator, so it is impossible to ensure that the adjustment is in place at one time, thereby more scrap products may be produced. Therefore, it is urgent to provide a method which can monitor the alignment of the pole lug in real time and automatically adjust the alignment of the pole lug according to the deviation of the pole lug in the winding process. SUMMARY

[0003] The purpose of the present application is to provide a winding cell manufacturing method, which can monitor the alignment of the pole lug in real time and automatically adjust the alignment of the pole lug according to the deviation of the pole lug in the winding process, improve the adjustment accuracy and reduce the scrap rate.

[0004] To achieve this purpose, the present application adopts the following technical scheme:

[0005] The present application discloses a winding cell manufacturing method, comprising the following steps: in response to satisfying a specified condition, measuring the length of the raw material and setting it as a detection value X; according to the specified length data, calculating the length deviation value AL corresponding to the detection value X, and when the absolute value of the length deviation value AL exceeds a preset threshold value AL0, determining that the pole lug deviates; when the pole lug deviates, adjusting the thickness of the pole piece according to the length deviation value AL to carry out the subsequent winding of the cell.

[0006] The winding cell manufacturing method disclosed by the present application has the following beneficial effects: in the method provided by the present application, the output length of the raw material in response to satisfying the specified condition is set as the detection value X; by calculating the size relationship between the absolute value of the length deviation value AL corresponding to the detection value X and the preset threshold value AL0, when the absolute value of the length deviation value AL is greater than the preset threshold value AL0, it is determined that the pole lug deviates. When the deviation of the pole lug is detected, the thickness of the pole piece can be adjusted according to the length deviation value AL to compensate for the misalignment of the pole lug in the winding process, to monitor the alignment of the pole lug in real time and automatically adjust the alignment of the pole lug according to the deviation of the pole lug in the winding process, improve the adjustment accuracy and reduce the scrap rate. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 is a flowchart of a winding electrode cell manufacturing method according to an embodiment of the present application;

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

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

[0010] Figure 4 is a structural schematic diagram of a deviation electrode cell according to an embodiment of the present application.

[0011] Reference signs:

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

[0013] The present application will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely intended for the purpose of interpretation of the present application and are not limiting to the present application. In addition, it should be noted that only the parts related to the present application are shown in the accompanying drawings for the purpose of description, rather than all the structures. In the description of the present application, the terms "upper", "lower", "left", "right", "front", "back" and the like orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are merely for the purpose of description and simplification of operation, and therefore cannot be understood as indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application.

[0014] The present application discloses a winding electrode cell manufacturing method, referring to Figure 1 shown, the winding electrode cell manufacturing method comprises the following steps: S1: in response to satisfying a specified condition, measuring the length of the raw material, and setting it as a detection value X; S2: according to the specified length data, calculating the length deviation value AL corresponding to the detection value X, and when the absolute value of the length deviation value AL exceeds a preset threshold value AL0, determining that the tab is deviated; S3: when the tab is deviated, adjusting the thickness of the electrode sheet according to the length deviation value AL to perform subsequent winding of the electrode 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 in the winding process, the tabs of the adjacent two layers are basically arranged in opposition and will not be deviated. However, due to the reasons of production and manufacturing, the thickness of the raw material will not be completely consistent, and in this case, the tabs of the adjacent two layers will be deviated in the winding process.

[0016] It is understood that in the winding cell manufacturing method provided by this invention, the output length of the raw material in response to meeting specified conditions can be set as the detection value X; by calculating the relationship between the absolute value of the length deviation value ΔL corresponding to the detection value X and the preset threshold ΔL0, when the absolute value of the length deviation value ΔL is greater than or equal to the preset threshold ΔL0, it is determined that the tab has deviated (refer to...). Figure 4 As shown, Figure 4 The diagram shows a deviated cell 900 with a misaligned tab. When a tab misalignment is detected, the thickness of the electrode sheet can be adjusted based on the length deviation value ΔL to compensate for tab misalignment during winding. This allows for real-time monitoring of tab alignment during winding and automatic adjustment of tab alignment based on the amount of tab deviation, improving adjustment accuracy and reducing scrap rate. When the absolute value of the length deviation value ΔL is less than the preset threshold ΔL0, it is determined that there is no tab deviation and no correction is needed. Therefore, the winding cell manufacturing method provided by this invention enables real-time monitoring of tab alignment during cell manufacturing and automatic adjustment of tab alignment based on the amount of tab deviation, improving adjustment accuracy, reducing scrap rate, and eliminating the need for additional sensors. Trigger conditions can be set directly through the winding needle 100 of the winding cell, making trigger condition setting convenient. It should be noted that, according to the reference... Figure 2 As shown, the raw materials required in the manufacturing process of the battery cell include a positive electrode sheet 200, a negative electrode sheet 300, an upper separator 400, and a lower separator 500. In the embodiments of the present invention, the raw materials can be any one of the positive electrode sheet 200, the negative electrode sheet 300, the upper separator 400, and the lower separator 500. In this case, 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 separator 400, and the lower separator 500. The raw materials in the embodiments of the present invention can also be at least two of the positive electrode sheet 200, the negative electrode sheet 300, the upper separator 400, and the lower separator 500. The measured length values ​​of the raw materials include Xpositive, Xnegative, Xupper, and Xlower, and the detection value X is the average of the measured length values ​​of the raw materials.

[0017] In practice, regardless of the situation described above, the principle of adjusting the electrode thickness based on the length deviation value ΔL remains the same. The only differences lie in the meaning of the length deviation value ΔL and the specific type of electrode being adjusted, as detailed below:

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

[0019] If the length detection value of the upper separator 400 and the lower separator 500 is taken as the detection value X, then the thickness of the positive electrode sheet 200 and / or the negative electrode sheet 300 is adjusted.

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

[0021] If the detection value X is the average of the length detection value of the negative electrode sheet 300 and the lower separator 500 (i.e. the average of Xnegativeand Xlower), the average of the length detection value of the negative electrode sheet 300 and the upper separator 400 (i.e. the average of Xnegativeand Xupper), or the average of the length detection value of the negative electrode sheet 300, the upper separator 400 and the lower separator 500 (i.e. the average of Xnegative, Xupperand Xlower), then the thickness of the negative electrode sheet 300 is adjusted.

[0022] If the detection value X is the average of the length detection value of the positive electrode sheet 200, the negative electrode sheet 300 and the lower separator 500 (i.e. the average of Xpositive, Xnegativeand Xlower), the average of the length detection value of the positive electrode sheet 200, the negative electrode sheet 300 and the upper separator 400 (i.e. the average of Xpositive, Xnegativeand Xupper), or the average of the length detection value of the positive electrode sheet 200, the negative electrode sheet 300, the upper separator 400 and the lower separator 500 (i.e. the average of Xpositive, Xnegative, Xupperand Xlower), then the thickness of the positive electrode sheet 200 and / or the negative electrode sheet 300 is adjusted.

[0023] The above steps S1-S3 are further described below with the detection value X being 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 can be understood that in the actual winding process, the positive electrode sheet 200 is continuously output, the winding needle 100 is continuously rotated, and the length detection value of the positive electrode sheet 200 output when the winding needle 100 rotates through the specified angle θ can be measured by the length measuring roller 600 arranged on the winding device arranged on the output path of the positive electrode sheet 200 and taken as the detection value. The specified condition of the winding needle 100 rotating through the specified angle θ is selected to facilitate the execution logic of the design method on the one hand, and the modification of the winding device is small and convenient to implement on the other hand.

[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. In order to facilitate recording, the specified angle θ can preferably be an integer multiple of 360°. It can be understood that the greater the specified angle θ, the more the number of turns of the winding needle 100, so the greater the thickness of the battery cell that has been wound on the winding needle 100, so it is possible to detect when the multi-layer tab deviation occurs, which is not conducive to improving the tab alignment. If the number of turns of the winding needle 100 is less, it is possible to appear multiple times without useful detection, which slows down the winding rate of the battery cell. In the present embodiment, the specified angle θ is controlled within the range of 360°-3600°, which can on the one hand ensure that the tab deviation is detected quickly during the winding process of the battery cell, which is conducive to improving the tab alignment of the battery cell, and on the other hand can control the total number of detections to ensure the winding rate of the battery cell, which is conducive 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 during batch production, the tab alignment of the battery cell will be detected, and in a batch, the battery cell with a tab deviation amount λ less than the deviation threshold λ0 is taken as the reference battery cell 800 Figure 3The length of the positive electrode sheet 200 measured when the winding needle 100 completes the 360° winding of the reference electrode core 800 is set as the reference length L, and the specified length data is set as an array according to the cumulative rotation angle of the winding needle 100 during the detection process. That is, when the reference electrode core 800 is manufactured, the winding needle 100 rotates 360°, 720°, 1080°, i*360°, and the length measuring roller 600 records i reference lengths L. At this time, the control system of the winding device can store a standard array {L1, L2, L3, …, Li} containing multiple reference lengths, and the standard array is used as the specified length data in step S2. Each data in the specified 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 records 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 meets the specified condition, and the length deviation value AL corresponding to the detection value X is the cumulative value of the single deviation value Ah i. The calculation formula of the single deviation value Ah i is: Ah i = reference length Li - real-time raw material output length Xi (the 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 adjusting the positive electrode sheet, AL = Ah1+ Ah2+ Ah3+ Ah4+ Ah5+ Ah6+ Ah7+ Ah8+ Ah9+ Ah10 at this time, Ah1= X1-L1, and the rest is sequentially followed. If the absolute value of AL is greater than the preset threshold AL0, it indicates that the deviation of the tab has occurred when the winding needle 100 rotates the 10th time. Specifically, if AL is a positive value, it indicates that the thickness of the positive electrode sheet is too large, and the thickness of the positive electrode sheet needs to be reduced when the winding needle 100 rotates the 11th time. If AL is a negative value, it indicates that the thickness of the positive electrode sheet is too small, and the thickness of the positive electrode sheet needs to be increased when the winding needle 100 rotates the 11th time, so as to realize the adjustment of the alignment degree of the tab, avoid the scrap due to the poor alignment degree of the tab, and improve the yield.

[0027] Optionally, the deviation threshold λ0 can range from 0.5mm to 10mm. Specifically, the deviation threshold λ0 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 deviation threshold λ0 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 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, it will increase the scrap rate. If the deviation threshold λ0 is too small, it will lead to too many adjustments to the thickness of the electrode sheet during the winding process, affecting normal production efficiency. In this embodiment, the deviation threshold λ0 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 tab deviation λ), and control the number of adjustments to the thickness of the electrode sheet, thus ensuring production efficiency.

[0028] Optionally, step S2 further includes: after each new battery cell is manufactured, 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 based on the newly wound battery cell. It is understood that in actual manufacturing, after each battery cell is wound, the tab alignment of this newly wound battery cell may be better or worse than the previously determined reference battery cell 800. During the implementation of the method, by comparing the tabs of the newly wound battery cell with the original reference battery cell 800, and then updating the reference battery cell 800 in real time, the tab alignment of each subsequent wound battery cell can be maximized, thereby improving the battery cell manufacturing yield.

[0029] In step S3, adjusting the electrode thickness based on the length deviation value ΔL includes: calculating an adjustment coefficient α based on the length deviation value ΔL. The adjustment coefficient α is used to correct the pressure applied by the electrode forming roller 700 to the electrode (positive electrode 200 in this embodiment) to adjust the thickness of the electrode (positive electrode 200 in this embodiment). It is understood that adjusting the electrode thickness by adjusting the pressure applied by the electrode forming roller 700 to the electrode is convenient for the execution logic of the design method and requires minimal modification to the winding equipment, making it easy to implement.

[0030] Optionally, the length deviation value ΔL and the adjustment coefficient α satisfy the following relationship: α=(((ΔL / (θ / 360)) / 6.28)*K)*Q+γ; where: θ is the specified angle through which the winding needle rotates 100, 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. The empirical constant K can be selected according to the model and thickness of the electrode sheet, and the compensation constants Q and γ can be selected according to the actual needs based on the degree of electrode sheet compaction. The magnitude of the adjustment coefficient α is the adjustment value of the pressure parameter of the electrode sheet shaping roller 700. When the length deviation value ΔL is greater than 0, the electrode sheet is too thick, and the pressure parameter needs to be reduced; when the length deviation value ΔL is less than 0, the electrode sheet is too thin, and the pressure parameter needs to be increased. 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, or 3. Of course, the empirical constant K can also be other values ​​within the range of 1-3, and is not limited to the examples above. 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, or 13.5. Of course, the compensation coefficient Q can also be other values ​​within the range of 2.5-13.5, and is not limited to the examples above. 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, or 0.008. Of course, the compensation constant γ can also be chosen from other values ​​within the range of 0.005-0.008, and is not limited to the examples above.

[0031] The following table provides specific values ​​for the reference length L of a reference cell 800 and the raw material output length of the cell during the manufacturing process. Table 1 also provides specific adjustment procedures for the adjustment coefficient α during the winding of a cell.

[0032] Table 1

[0033] Cumulative rotation angle of the winding pin 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 value ΔL corresponding to the detection value X exceeds 0.5, it is determined that the tab has deviated and the thickness of the electrode (positive electrode 200 in this embodiment) needs to be adjusted.

[0035] The length deviation ΔL and the adjustment coefficient α satisfy the following 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 a specified angle θ, and θ is 3600°, the reference length L is 289.736, and the detection value X is 289.864. According to the calculation, the length deviation value ΔL = 0.7 can be obtained at this time. Substituting into the formula, we can get α = 0.018 MPa. This indicates that the pressure of the electrode shaping roller 700 on the electrode needs to be reduced at this time. That is, when the winding needle 100 winds for the 11th turn, the pressure of the electrode shaping roller 700 needs to be reduced by 0.018 MPa.

[0039] Referring to Table 1, if in step S1 the specified condition is that the winding needle 100 rotates through a specified angle θ, and θ is 7200°, the reference length L is 311.219, and the detection value X is 311.474. According to the calculation, the length deviation value ΔL at this time is 2.68. Substituting into the formula, we can get α = 0.12 MPa. This indicates that the pressure of the electrode shaping roller 700 on the electrode needs to be reduced at this time. Therefore, when the winding needle 100 winds for the 21st turn, the pressure of the electrode shaping roller 700 needs to be reduced by 0.12 MPa.

[0040] Of course, in other embodiments of the present invention, the specified conditions may also be multiple conditions such as the needle winding turning 100 times for a preset time, the raw material winding turning through a preset angle, and the raw material winding turning through a preset time, etc., to adjust the tab alignment. The specific conditions can be selected according to actual needs.

[0041] 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.

[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 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 method for manufacturing a wound battery cell, characterized in that, Includes the following steps: Set the output length of the raw material that meets the specified conditions as the detection value X; Based on the specified length data, calculate the length deviation value ΔL corresponding to the detection value X. If the absolute value of the length deviation value ΔL exceeds the preset threshold ΔL0, it is determined that the tab has deviated. When the tab deviates, the thickness of the electrode is adjusted according to the length deviation value ΔL in order to proceed with the subsequent winding of the battery cell. The specified length data includes at least one reference length L, and each reference length L corresponds to a cumulative rotation angle of a spinning needle; The detected value X corresponds to the real-time cumulative rotation angle of the coiling needle, and the length deviation value ΔL is the cumulative value of a single deviation value Δhi. The calculation formula for the single deviation value Δhi is: Δhi = reference length Li - real-time raw material output length Xi; where: 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], and j = the real-time cumulative rotation angle of the winding needle / 360°; The length deviation value ΔL is used to adjust the thickness of the electrode sheet, including: calculating an adjustment coefficient α based on the length deviation value ΔL, wherein the adjustment coefficient α is used to correct the pressure applied to the electrode sheet by the electrode sheet forming roller, so as to adjust the thickness of the electrode sheet; The length deviation value ΔL and the adjustment coefficient α satisfy the following 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.

2. The method for manufacturing a wound battery cell according to claim 1, characterized in that, A battery cell with a tab deviation λ less than the deviation threshold λ0 is used as a reference battery cell; wherein: during the winding of the reference battery cell, the raw material output length detected by 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 0.5mm to 10mm.

4. The method for manufacturing a wound battery cell according to claim 3, characterized in that, After each 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 original reference battery cell is replaced with the newly wound battery cell, and the specified length data is determined with 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 raw materials include any one of the following: positive electrode sheet, negative electrode sheet, upper separator, and lower separator.

8. The method for manufacturing a wound battery cell according to claim 1, characterized in that, The raw materials include at least two of the following: positive electrode sheet, negative electrode sheet, upper separator, and lower separator. The measured length values ​​of the raw materials include Xpositive, Xnegative, Xupper, and Xlower, and the measured value X is the average of the measured length values ​​of the raw materials.

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