Method for winding electrode sheet into roll and rectifying deviation during winding

Abstract

This invention discloses a method for winding and rewinding electrode sheets, comprising the following steps: Step S1: Setting standard values ​​for the distances between the edge positions of the positive and negative electrode sheets and the set reference positions; Step S2: Detecting the differences between the edge positions of the positive and negative electrode sheets and the standard values; Step S3: Calculating the average value X of the differences between the edge distances of the positive and negative electrode sheets and the standard values ​​after N turns of the currently wound core, excluding the N turns. 正前 X 正后 X 负前 X 负后 X 正中 X 负中 Step S4: During the winding correction process, the first N turns of the next core are pre-corrected and winding begins. Step S5: During the rewinding correction process, the last N turns of the core are pre-corrected. The beneficial effects of this invention are: by detecting and analyzing the winding correction data of the currently wound core, it guides the pre-winding and rewinding correction of the next core, reducing defects such as electrode wrinkling caused by excessive pre-winding and rewinding correction amplitude.

Description

Technical Field

[0001] This invention relates to the field of lithium battery manufacturing technology, and more particularly to a core-wound electrode correction technology. Background Technology

[0002] The distance between the positive and negative electrode sheets is one of the key monitoring indicators for the wound core produced. If the positive electrode exceeds the negative electrode or the negative electrode does not completely cover the positive electrode, it will cause lithium plating and short circuits in the core later on, and in severe cases, it can cause the cell to catch fire or explode. To ensure the coverage requirements of the positive and negative electrode sheets and to ensure the consistency of winding, most winding machines currently use a three-stage correction mechanism, including unwinding EPC correction, process serpentine correction, and in-winding clamping correction. By correcting the electrode sheets in real time during the winding process, the electrode sheet material line is stabilized, ensuring that the coverage meets the requirements and that the electrode sheets do not wrinkle.

[0003] For example, application publication number CN116031502A discloses a method for predicting wrinkling of electrode sheets in core winding. The method includes: S1, setting a CCD camera at the winding needle to detect the deviation fluctuation between the electrode sheet edge position and a set reference position; S2, detecting the correction amplitude of each correction mechanism between the unwinding and winding processes; S3, based on the correction amplitude, calculating the absolute value ΔT of the difference between the maximum correction amplitude Tmax of each correction mechanism within a fixed length L during the winding process and the difference between two adjacent correction amplitude data, and calculating the deviation between the obtained electrode sheet edge position and the obtained set reference position at the winding needle, and the absolute value ΔH of the difference between two adjacent electrode sheet position deviation values, based on the deviation fluctuation.

[0004] S4. The maximum correction amplitude Tmax, the absolute value of the difference between two adjacent correction amplitude data ΔT, and the absolute value of the difference between two adjacent values ​​of the electrode position deviation ΔH are compared with the set parameters to predict whether the electrode will wrinkle. Although this correction method can correct the deviation during the winding process, it is set during the electrode transportation process and does not detect and correct the deviation during the winding and unwinding processes.

[0005] When the electrode sheet is wound into the winding process and when it is wound up after cutting, the electrode sheet is in a free state. The electrode sheet is very prone to deviation, which can cause poor coverage during winding and unwinding. In severe cases, the electrode sheet may wrinkle due to excessive deviation correction.

[0006] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0007] The technical problem to be solved by this invention is: how to solve the problem that the current method does not correct the deviation when the wound electrode is wound and when it is wound after cutting. The electrode is in a free state when it is wound and when it is wound, and the electrode is very easy to deviate, which can lead to adverse phenomena such as short circuit, fire and explosion of the core.

[0008] The present invention solves the above-mentioned technical problems through the following technical means:

[0009] The method for winding and rewinding electrode sheets includes the following steps:

[0010] Step S1: Set the standard value of the distance between the edge position of the positive electrode and the negative electrode and the set reference position;

[0011] Step S2: Install a detection mechanism at the needle winding point to detect the difference between the edge positions of the positive and negative electrode plates and the standard value;

[0012] Step S3: Calculate the average of the differences between the edge distances of the positive and negative electrode sheets before and after the current wound core (N turns) and the standard value, which is X. 正前 X 正后 X 负前 X 负后 Excluding the N turns before and after, the mean difference between the edge distance of the positive and negative electrodes and the standard value is X. 正中 X 负中 ;

[0013] Step S4: Input Correction Process: Calculate X 正前 With X 正中 Differences X1 and X 负前 With X 负中 The difference is X2, based on X 正中 X 负中 The size of X1 and X2, the length within N turns before the next core, the positive and negative electrode sheets are fed into the clamping and correction according to the above four data values ​​to determine the correction in advance and start winding.

[0014] Step S5: Winding and Correction Process: Calculate the average values ​​X3 and X4 of the differences between the edge distances of the positive and negative electrodes and the standard values ​​during the winding process, excluding the first N turns. Calculate X... 正后 With X 正中 Difference X5, X 负后 With X 负中 The difference X6, based on the values ​​of X3, X4, X5, and X6, determines the alignment of the positive and negative electrode plates within the N turns of this core, according to the logic of the above four data values.

[0015] This invention uses data from the current winding core to guide the early correction of the next core's entry and exit points. This can reduce material line fluctuations caused by the free state of the first and last n turns, reduce poor electrode coating in the first and last n turns, and reduce electrode wrinkling caused by excessive correction during entry and exit points.

[0016] Preferably, in step S2, the specific method for detecting the difference between the edge position of the positive electrode and the negative electrode and the standard value is as follows: the detection is carried out according to the winding angle or the length of the electrode, and no less than 2 sets of data are detected for each turn of the positive electrode and the negative electrode. The difference between the edge of the non-tab side electrode and the set reference position is compared with the standard value to obtain the difference between the edge distance of the positive electrode and the negative electrode and the standard value.

[0017] Preferably, in step S3, the straight-line distance D from the positive and negative electrode clamping rollers to the feed edge of the winding needle is measured. 正 D 负 The average length of each turn of the core electrode sheet is L; D 正 The integer part of L and D 负 The maximum value between the two digits excluding the integer part of L is denoted as N. If the maximum value between the two digits is greater than 3, then N = 3.

[0018] Preferably, in step S3, during the winding correction process, preset limit thresholds A1, A2, and B1 are used.

[0019] Judgment | X 正中 |<A1、|X 负中 |<A1 or|X 正中 |>A2、|X 负中 When |>A2, if |X1|≤B1 and |X2|≤B1, the feeding clamping and correction of the positive and negative electrode sheets within the first N turns of the next core are corrected in advance according to |X1| and |X2|. However, if |X1|>B1 and |X2|>B1, the feeding clamping and correction are all corrected in advance according to the value of B1.

[0020] Preferably, in step S3, during the winding correction process,

[0021] Determine A1≤|X 正中 |≤A2、A1≤|X 负中 When |≤A2, and when |X1|<B1 and |X2|<B1, the length of the positive and negative electrode sheets in the first n turns of the next core is adjusted according to X1 and X2. 正中 The sum of X, X2 and X 负中 The sum of the values ​​is used to correct the deviation in advance, but when |X1|≥B1 and |X2|≥B1, the material feeding clamping deviation correction is based on the sum of B1 and X. 正中 X 负中 The sum of these factors should be corrected in advance.

[0022] When summing, the sign of B1 is the same as that of X1 and X2, and the direction of correction is determined based on the signs of X1 and X2.

[0023] Preferably, in step S3, during the winding and correction process, when it is determined that |X3|<A1, |X4|<A1 or |X3|>A2, |X4|>A2, when |X5|≤B1, |X6|≤B1, the length of the positive and negative electrode sheets in the feeding clamping correction within N turns after winding the core is corrected according to |X5|, |X6|. However, when |X5|>B1, |X6|>B1, the feeding clamping correction is corrected according to the value of B1.

[0024] Preferably, in step S3, during the winding and correction process, when it is determined that A1≤|X3|≤A2 and A1≤|X4|≤A2, and when |X5|<B1 and |X6|<B1, the length of the positive and negative electrode sheets within N turns after winding the core is corrected according to the sum of X3 and X5 and the sum of X4 and X6. However, when |X1|≥B1 and |X2|≥B1, the length of the positive and negative electrode sheets is corrected in advance according to the sum of B1 and X5 and X6. When summing, the sign of B1 is consistent with that of X3 and X4, and the correction direction is determined according to the sign of X3 and X4.

[0025] Preferably, A1 has a value range of 0-0.3, A2 has a value range of 0.5-1.5, and B1 has a value range of 0.3-1.0.

[0026] Preferably, all correction values ​​must not exceed the set maximum correction limit C, where C ranges from 0.5 to 3.0. If the value exceeds the limit, the correction value is set to the value of C.

[0027] Preferably, the detection mechanism in step S2 is a CCD camera.

[0028] The advantages of this invention are:

[0029] This invention uses data from the current winding core to guide the early correction of the next core's entry and exit points. This can reduce material line fluctuations caused by the free state of the first and last n turns, reduce poor electrode coating in the first and last n turns, and reduce electrode wrinkling caused by excessive correction during entry and exit points. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure during winding according to an embodiment of the present invention;

[0031] Numbering on the map:

[0032] 1. Coiling needles;

[0033] 2. Clamping and correction mechanism. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] In Example 1, the core tabs are distributed on one side, and there is a CCD camera on each side of the winding needle. The electrode sheet is usually a long strip, and during the winding process, it needs to be fed into the material according to a preset trajectory. The electrode sheet may deviate during the continuous feeding process, causing the alignment of the electrode sheet edges after winding to not meet the requirements.

[0036] The method for winding and rewinding electrode sheets includes the following steps:

[0037] Step S1: Set the standard value of the distance between the edge position of the positive electrode and the negative electrode and the set reference position;

[0038] The edge position is the side of the positive or negative electrode along its length. For example, the distance between the edge position of the positive electrode and the axial end face of the winding needle is set as the standard value Z.

[0039] Step S2: Install a detection mechanism at the needle winding point to detect the difference between the edge positions of the positive and negative electrode plates and the standard value;

[0040] Specifically, the method for detecting the difference between the edge position of the positive and negative electrode and the standard value is as follows: based on the winding angle or electrode length, at least two sets of data are detected for each turn of the positive and negative electrode. The difference between the edge of the non-tab side electrode and the set reference position is compared with the standard value to obtain the difference between the edge distance of the positive and negative electrode and the standard value.

[0041] The CCD cameras on both sides of the winding needle detect the difference between the distance of the electrode edge and the standard value during the winding process. In this embodiment, the CCD detection data is 1 set of data for every 180° rotation of the winding needle, for a total of 2 sets of data.

[0042] Step S3: Calculate the average of the differences between the edge distances of the positive and negative electrode sheets before and after the current wound core (N turns) and the standard value, which is X. 正前 X 正后 X 负前 X 负后 Excluding the N turns before and after, the mean difference between the edge distance of the positive and negative electrodes and the standard value is X. 正中 X 负中 ;

[0043] like Figure 1 As shown, during the conveying process of the positive and negative electrode sheets, clamping and correction mechanisms 2 are respectively provided, each including clamping rollers. The straight-line distance D from the clamping rollers of the clamping and correction mechanisms of the positive and negative electrode sheets to the feed edge of the winding needle 1 is measured. 正 D 负 The average length of each turn of the core electrode sheet is L; D 正 The integer part of L and D 负 The maximum value between the two digits excluding the integer part of L is denoted as N. If the maximum value between the two digits is greater than 3, then N = 3.

[0044] Step S4: Input Correction Process: Calculate X 正前 With X 正中 Differences X1 and X 负前 With X 负中 The difference is X2, based on X 正中 X 负中 The size of X1 and X2, the length within N turns before the next core, the positive and negative electrode sheets are fed into the clamping and correction according to the above four data values ​​to determine the correction in advance and start winding.

[0045] A1, A2, and B1 are preset limit comparison values, which are the average X values ​​of the differences between the edge distances of the positive and negative electrode plates and the standard values, excluding the N turns before and after. 正中 X 负中 The upper and lower limits of these differences are defined as X1, X2, X3, X4, X1, X2, X5, and X6. Normally, the smaller the values ​​of A1, A2, and B1, the better. However, insufficient equipment capacity and abnormal incoming materials can cause fluctuations. The specific values ​​are mostly empirical values ​​from actual operation.

[0046] Specifically, determine |X 正中 |<A1、|X 负中 |<A1 or|X 正中 |>A2、|X 负中 When |>A2, if |X1|≤B1 and |X2|≤B1, the feeding clamping and correction of the positive and negative electrode sheets within the first N turns of the next core are corrected in advance according to |X1| and |X2|. However, if |X1|>B1 and |X2|>B1, the feeding clamping and correction are all corrected in advance according to the value of B1.

[0047] Determine A1≤|X 正中 |≤A2、A1≤|X 负中 When |≤A2, and when |X1|<B1 and |X2|<B1, the length of the positive and negative electrode sheets in the first N turns of the next core is adjusted according to X1 and X2. 正中 The sum of X, X2 and X 负中 The sum of the values ​​is used to correct the deviation in advance, but when |X1|≥B1 and |X2|≥B1, the material feeding clamping deviation correction is based on the sum of B1 and X.正中 X 负中 The sum of these factors should be corrected in advance.

[0048] When summing, the sign of B1 is the same as that of X1 and X2, and the direction of correction is determined based on the signs of X1 and X2.

[0049] Step S5: Winding and Correction Process: Calculate the average values ​​X3 and X4 of the differences between the edge distances of the positive and negative electrodes and the standard values ​​during the winding process, excluding the first N turns. Calculate X... 正后 With X 正中 Difference X5, X 负后 With X 负中 The difference X6, based on the values ​​of X3, X4, X5, and X6, determines the alignment of the positive and negative electrode plates within the N turns of this core, according to the logic of the above four data values.

[0050] Specifically, when |X3| < A1, |X4| < A1 or |X3| > A2, |X4| > A2, if |X5| ≤ B1, |X6| ≤ B1, the positive and negative electrode sheets are corrected according to |X5| and |X6| within N turns after winding the core. However, if |X5| > B1, |X6| > B1, the feeding clamping correction is corrected according to B1. When A1 ≤ |X3| ≤ A2, A1 ≤ |X4| When |≤A2, and |X5|<B1, |X6|<B1, the positive and negative electrode sheets within N turns after winding the core are corrected by the sum of X3 and X5, and the sum of X4 and X6. However, when |X1|≥B1, |X2|≥B1, the correction is completed in advance by the sum of B1 and X5, X6. When summing, the sign of B1 is the same as that of X3 and X4, and the correction direction is determined by the sign of X3 and X4.

[0051] The value range of A1 is 0-0.3, the value range of A2 is 0.5-1.5, and the value range of B1 is 0.3-1.0.

[0052] Preferably, all correction values ​​must not exceed the set maximum correction limit C, where C ranges from 0.5 to 3.0. If the value exceeds the limit, the correction value is set to the value of C.

[0053] All correction values ​​refer to the values ​​mentioned above that are used to correct the deviation to the correct position, such as "|X1|, |X2|" in "the deviation correction of the positive and negative electrode sheets in the N turns before the next core is corrected to the correct position in advance according to |X1|, |X2|"; and "the B1 value" in "when |X1|>B1, |X2|>B1, the deviation correction of the feeding clamp is corrected to the correct position in advance according to the B1 value".

[0054] In this embodiment, the following specific example is given:

[0055] Measure the straight-line distance D from the positive and negative electrode clamping rollers to the feed edge of the winding needle. 正 =343mm, D 负 =306mm, the average length of each turn of the core electrode sheet is L=144.2mm, D 正 / L=2.3786, D 负 / L = 2.122. Based on taking the integer part and denoteing the maximum value between the two as N, we get N = 2; the standard value for the distance from the edge of the positive electrode plate on the non-tab side to the baseline is set as Z. 正 =0.5, the standard value of the distance from the edge of the negative electrode to the baseline is Z. 负 =3.0, the non-polar ear-side test data are summarized as follows:

[0056]

[0057]

[0058] Calculate X 正前 With X 正中 Difference X1, X 负前 With X 负中 The difference is X2, calculate X. 正后 With X 正中 Difference X5, X 负后 With X 负中 Difference x6,

[0059] Based on the above data, we can calculate: X1 = 0.484 - 0.172 = 0.312, X2 = 0.363 - 0.625 = -0.262, X5 = 0.282 - 0.172 = 0.11, X6 = 0.953 - 0.625 = 0.328.

[0060] The values ​​for the error correction judgment logic for in-winding and rewinding are defined as follows: A1 = 0.2, A2 = 0.7, B1 = 0.5. The maximum error correction limit is set to C = 0.6.

[0061] |X 正中 | refers to X 正中 The absolute value of , and the same applies to the others.

[0062] According to "determination | X" 正中 |<A1、|X 负中 |<A1 or|X 正中 |>A2、|X 负中 When | > A2, and |X1| ≤ B1 and |X2| ≤ B1, the feeding clamping and correction of the positive and negative electrode sheets within the first N turns of the next core are corrected in advance according to |X1| and |X2|, respectively. However, when |X1| > B1 and |X2| > B1, the feeding clamping and correction are all corrected in advance according to the value of B1. It is determined that A1 ≤ |X1| > B1.正中 |≤A2、A1≤|X 负中 When |≤A2, and when |X1|<B1 and |X2|<B1, the length of the positive and negative electrode sheets in the first N turns of the next core is adjusted according to X1 and X2. 正中 The sum of X, X2 and X 负中 The sum of the values ​​is used to correct the deviation in advance, but when |X1|≥B1 and |X2|≥B1, the material feeding clamping deviation correction is based on the sum of B1 and X. 正中 X 负中 The principle is to correct the deviation in advance when summing; when summing, the sign of B1 is consistent with that of X1 and X2, and the direction of correction is determined according to the sign of X1 and X2.

[0063] Because of |X 正中 If |X1| is 0.172, which is less than A1 = 0.2, and |X1| ≤ B1, the positive electrode sheet length within the first two turns of the next core should be pre-corrected according to |X1| = 0.312.

[0064] |X 负中 | is 0.625, located between A1 = 0.2 and A2 = 0.7, and |X2| < B1. The length of the negative electrode sheet in the first two turns of the next core is adjusted according to X2 and X... 负中 The sum was corrected in advance, X2 and X 负中 The sum is -0.264 + 0.625 = 0.363. Since X2 is negative, the correction direction is the side away from the baseline.

[0065] According to the criteria, when |X3|<A1, |X4|<A1 or |X3|>A2, |X4|>A2, if |X5|≤B1, |X6|≤B1, the positive and negative electrode sheets should be corrected according to |X5|, |X6| within N turns after winding the core. However, if |X5|>B1, |X6|>B1, the feeding clamping correction should be corrected according to B1. When |X3|≤A1, |X4|≤A2, or |X3|>A2, the feeding clamping correction should be corrected according to B1. At time 2, when |X5| < B1 and |X6| < B1, the positive and negative electrode sheets are corrected within N turns after winding the core by the sum of X3 and X5 and X4 and X6. However, when |X1| ≥ B1 and |X2| ≥ B1, the correction is completed in advance by the sum of B1 and X5 and X6. When summing, the sign of B1 is consistent with that of X3 and X4, and the correction direction is determined according to the sign of X3 and X4.

[0066] Since |X3|=0.484, which is greater than A1=0.2 and less than A2=0.7, and |X5|=0.11<B1, the positive electrode sheet length is corrected within 2 turns after winding the core according to the sum of X3 and X5. The sum of X3 and X5 is 0.484+0.11=0.594. Since the value of X3 is positive, the correction direction is closer to the baseline.

[0067] Since |X4|=0.811>A2 and |X6|=0.328≤B1, the negative electrode sheet length is corrected within 2 turns after the core is wound, according to |X6|=0.382. Since X4 is a positive number, the correction direction is closer to the baseline.

[0068] In summary, it can be determined that: before the first two turns of the electrode sheet are wound into the next core, the positive electrode sheet is pre-corrected with a deviation value of 0.312, correcting towards the side closer to the baseline, and the negative electrode sheet is pre-corrected with a deviation value of 0.363, correcting towards the side farther from the baseline, and then the electrode sheet winding begins; when the last two turns of the electrode sheet are wound into the core, the positive electrode sheet is pre-corrected with a deviation value of 0.594, correcting towards the side closer to the baseline, and the negative electrode sheet is pre-corrected with a deviation value of 0.328, correcting towards the side closer to the baseline.

[0069] Example 2:

[0070] Similar to the winding CCD detection in Implementation Case 1, the values ​​for the winding and unwinding correction judgment logic are still defined as follows: A1 = 0.2, A2 = 0.7, B1 = 0.5. The maximum correction limit is set to C = 0.6. The non-electrode side detection data has changed; the calculations are summarized below:

[0071]

[0072] Based on the above data, we can calculate that: X1 = 0.961, X2 = -0.966, X5 = 0.585, X6 = 0.455.

[0073] According to the judgment principle in Example 1, it can be determined that: before the first two turns of the electrode sheet are wound into the next core, the positive electrode sheet is corrected in advance by a value of 0.282, and is corrected towards the side closer to the baseline; the negative electrode sheet is corrected in advance by a value of 0.6, and is corrected towards the side farther from the baseline; then the sheet feeding and winding begins. However, when the last two turns of the electrode sheet are wound into the core, the positive electrode sheet is corrected by a value of 0.6, and is corrected towards the side closer to the baseline; the negative electrode sheet is corrected by a value of 0.455, and is corrected towards the side closer to the baseline.

[0074] Example 3:

[0075] Similar to the CCD winding detection in Implementation Case 1, the values ​​for the winding and unwinding correction judgment logic are defined as follows: A1 = 0.1, A2 = 0.5, B1 = 0.4. The maximum correction limit is set to C = 0.5. The non-electrode side detection data is summarized as follows:

[0076]

[0077] Based on the above data, we can calculate that: X1 = 0.312, X2 = -0.262, X5 = 0.11, X6 = 0.328.

[0078] According to the judgment principle in Example 1, it can be determined that: before the first two turns of the electrode sheet are wound into the next core, the positive electrode sheet is corrected in advance by a value of 0.484, and is corrected towards the side closer to the baseline; the negative electrode sheet is corrected in advance by a value of 0.262, and is corrected towards the side farther from the baseline. Then the sheet feeding and winding begins. When the last two turns of the electrode sheet are wound into the core, the positive electrode sheet is corrected by a value of 0, and is not corrected in advance; the negative electrode sheet is corrected by a value of 0.5, and is corrected towards the side closer to the baseline.

[0079] In the above embodiments, the correction mechanism can employ existing technology. Correction refers to the ability to correct the position of the electrode when it deviates from a set position, thereby improving the alignment of the electrode 1's edge after winding. For example, during the continuous movement of the electrode 1, the edge of the electrode 1 along its width direction may deviate from the set position. In this case, the correction mechanism can move the electrode 1 along its width direction to restore the edge of the electrode 1 to the set position.

[0080] This embodiment detects and analyzes the data of the currently wound core for winding correction, and guides the early correction of the next core's entry and end. This can reduce material line fluctuations caused by the free state of the first and last n turns, reduce the situation of poor electrode coating in the first and last n turns, and reduce the problem of electrode wrinkling caused by excessive winding and unwinding correction.

[0081] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for winding and correcting deviations in the winding of electrode sheets, characterized in that, Includes the following steps: Step S1: Set the standard value of the distance between the edge positions of the positive and negative electrode plates and the set reference position; Step S2: Install a detection mechanism at the needle winding point to detect the difference between the edge positions of the positive and negative electrode plates and the standard value; Step S3: Calculate the average of the differences between the edge distances of the positive and negative electrode sheets before and after the current wound core (N turns) and the standard value, which is X. 正前 X 正后 X 负前 X 负后 Excluding the N turns before and after, the mean difference between the edge distance of the positive and negative electrodes and the standard value is X. 正中 X 负中 ; In step S3, during the winding correction process, preset limit thresholds A1, A2, and B1 are used. Judgment | X 正中 |<A1、|X 负中 |<A1 or|X 正中 |>A2、|X 负中 When |>A2, if |X1|≤B1 and |X2|≤B1, the feeding clamping and correction of the positive and negative electrode sheets within the first N turns of the next core are corrected in advance according to |X1| and |X2|. However, if |X1|>B1 and |X2|>B1, the feeding clamping and correction are all corrected in advance according to the value of B1. In step S3, during the winding correction process... Determine A1≤|X 正中 |≤A2、A1≤|X 负中 When |≤A2, and when |X1|<B1 and |X2|<B1, the length of the positive and negative electrode sheets in the first n turns of the next core is adjusted according to X1 and X2. 正中 The sum of X, X2 and X 负中 The sum of the values ​​is used to correct the deviation in advance, but when |X1|≥B1 and |X2|≥B1, the material feeding clamping deviation correction is based on the sum of B1 and X. 正中 X 负中 The sum of these factors should be corrected in advance. When summing, the sign of B1 is the same as that of X1 and X2, and the direction of correction is determined based on the signs of X1 and X2. Step S4: Input Correction Process: Calculate X 正前 With X 正中 Differences X1 and X 负前 With X 负中 The difference is X2, based on X 正中 X 负中 The values ​​of X1 and X2, the length within N turns before the next core, the positive and negative electrode sheets are fed into the clamping and correction according to the above four data values ​​to determine the correction in advance and start winding. Step S5: Winding and Correction Process: Calculate the average values ​​X3 and X4 of the differences between the edge distances of the positive and negative electrodes and the standard values ​​during the winding process, excluding the first N turns. Calculate X... 正后 With X 正中 Difference X5, X 负后 With X 负中 The difference X6, based on the values ​​of X3, X4, X5, and X6, determines the alignment of the positive and negative electrode plates within the N turns of this core, according to the logic of the above four data values.

2. The method for winding and rewinding the electrode sheet according to claim 1, characterized in that, In step S2, the specific method for detecting the difference between the edge position of the positive electrode and the negative electrode and the standard value is as follows: the detection is carried out according to the winding angle or the length of the electrode. At least two sets of data are detected for each turn of the positive electrode and the negative electrode. The difference between the edge of the non-tab side electrode and the set reference position is compared with the standard value to obtain the difference between the edge distance of the positive electrode and the negative electrode and the standard value.

3. The method for winding and rewinding the electrode sheet according to claim 1, characterized in that, In step S3, the straight-line distance D from the positive electrode sheet and the negative electrode sheet clamping and correcting roller to the feed edge of the winding needle is measured. 正 D 负 The average length of each turn of the core electrode sheet is L; D 正 The integer part of L and D 负 The maximum value between the two digits excluding the integer part of L is denoted as N. If the maximum value between the two digits is greater than 3, then N=3.

4. The method for winding and rewinding the electrode sheet according to claim 1, characterized in that, In step S3, during the winding and correction process, preset limit thresholds A1, A2, and B1 are used. When it is determined that |X3|<A1, |X4|<A1 or |X3|>A2, |X4|>A2, if |X5|≤B1, |X6|≤B1, the positive and negative electrode sheets are corrected according to |X5|, |X6| within N turns after winding the core. However, if |X5|>B1, |X6|>B1, the feeding clamping correction is corrected according to the value of B1.

5. The method for winding and rewinding the electrode sheet according to claim 4, characterized in that, In step S3, during the winding and correction process, when it is determined that A1≤|X3|≤A2 and A1≤|X4|≤A2, and when |X5|<B1 and |X6|<B1, the positive and negative electrode sheets within N turns after winding the core are corrected according to the sum of X3 and X5 and the sum of X4 and X6. However, when |X1|≥B1 and |X2|≥B1, the feeding clamping correction is corrected in advance according to the sum of B1 value and X5 and X6. When summing, the sign of B1 value is consistent with that of X3 and X4, and the correction direction is determined according to the sign of X3 and X4 values.

6. The method for winding and rewinding the electrode sheet according to any one of claims 1-5, characterized in that, The value range of A1 is 0-0.3, the value range of A2 is 0.5-1.5, and the value range of B1 is 0.3-1.

0.

7. The method for winding and rewinding the electrode sheet according to claim 6, characterized in that, All correction values ​​must not exceed the set maximum correction limit C, where C ranges from 0.5 to 3.

0. If the value exceeds the limit, the correction value will be the value of C.

8. The method for winding and rewinding the electrode sheet according to claim 1, characterized in that, The detection mechanism in step S2 is a CCD camera.

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