Method for adjusting roll gap based on rolling speed

Abstract

The invention provides a method for adjusting a roll gap based on a rolling speed, and relates to the technical field of lithium battery pole piece manufacturing processes. The method comprises the following steps: presetting a pole piece thickness standard value and an allowable deviation thereof, recording corresponding data of a roll gap and a rolling speed, fitting a relational expression, establishing a mathematical model, and determining the adjustment amount of the roll gap when the rolling speed changes. In the rolling process, the operation side and the second roll gap are automatically adjusted according to the real-time change of the rolling speed, and it is ensured that the thickness of the pole piece is always within the standard deviation range. The method effectively solves the problem that the thicknesses of the pole pieces are inconsistent due to the change of the rolling speed, the consistency and the stability of the thicknesses of the pole pieces are remarkably improved, errors and lagging of manual operation are reduced, the automation and the production efficiency of the rolling process are improved, the quality of the pole pieces is improved, and meanwhile the subsequent procedure problems caused by abnormal thickness are reduced. The technology is simple and easy to implement and high in applicability, additional equipment does not need to be added, and the method is an efficient and practical automatic solution.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium battery pole piece manufacturing process, and particularly relates to a method for adjusting a roll gap based on a rolling speed. BACKGROUND

[0002] Lithium battery pole piece manufacturing is a complex and precise process, and the uniformity of the pole piece thickness directly affects the compaction density, discharge efficiency and product quality of the winding process of the lithium battery. At present, the rolling and thickness real-time detection are independently completed by a rolling machine and a laser thickness gauge, and the roll gap needs to be adjusted manually according to the thickness detection result. However, the pole piece thickness is different under different rolling speeds, especially the thickness rebound is inconsistent at high and low speeds, and the roll gap cannot be adjusted in time by the operator during frequent stop-start and acceleration-deceleration processes, which affects the thickness consistency.

[0003] The front part of the rolling machine roller is called the operation side, which is the side operated, adjusted and monitored by the staff, and has handle, button and other control devices. These devices are used to start / stop the rolling machine, adjust the rolling parameters, emergency stop and monitor the running state, and the first roll gap refers to the gap between the rollers close to the operation side of the device; the rear part of the rolling machine roller is called the transmission side, which is directly connected with the main drive system, and the second roll gap refers to the gap between the rollers close to the transmission side of the device.

[0004] In the prior art, for example, a rolling machine control method, system and device are disclosed in Chinese patent application No. 202410389954.X, and the deficiency of the patent is that the formula calculation is relatively complex, and the complexity of the result is high. SUMMARY

[0005] To solve the above problems, the present application provides a method for adjusting the roll gap based on the rolling speed, which automatically adjusts the roll gap according to the change of the rolling speed, realizes the real-time optimization of the pole piece thickness, and reduces the problem that the manual adjustment is not timely or unreasonable. The method significantly improves the consistency of the pole piece thickness, reduces the thickness difference at high and low speeds, improves the problems such as the dislocation of the core tab, and improves the product quality.

[0006] Based on the above analysis, the present application is given, and the specific implementation scheme is as follows: a method for adjusting the roll gap based on the rolling speed, comprising the following steps:

[0007] S1: setting a standard value H of the pole piece thickness, a standard value allowable deviation and a rolling speed V, adjusting the first roll gap and the second roll gap so that the pole piece thickness is within the allowable deviation range of the standard value, recording the first roll gap and the second roll gap at this time, recording the first roll gap as F1, and recording the second roll gap as F2;

[0008] S2: repeating S1, collecting multiple sets of data of the rolling speed V, the first roll gap F1 and the second roll gap F2, and fitting the relationship between the rolling speed V and the first roll gap F1 and the relationship between the rolling speed V and the second roll gap F2, respectively;

[0009] S3: according to the relationships in S2, obtaining the first roll gap F1 and the second roll gap F2 corresponding to different rolling speeds V, thereby obtaining the first roll gap variation ΔF1 and the second roll gap variation ΔF2 corresponding to the rolling speed V in any speed range;

[0010] S4: according to the first roll gap variation ΔF1 and the second roll gap variation ΔF2 in S3, adjusting the first roll gap F1 and the second roll gap F2 when the rolling speed V changes, to ensure that the thickness of the pole piece is within the standard deviation range.

[0011] The pole piece first passes through the first roll gap and is rolled for the first time to reach the standard value H, and then passes through the second roll gap for the second time to make the thickness within the allowable deviation of the standard value.

[0012] The present application collects multiple sets of corresponding data of the rolling speed V, the first roll gap F1 and the second roll gap F2, uses these data to fit the relationship curve between the rolling speed V and the first roll gap F1 and the second roll gap F2, and establishes a mathematical model to accurately describe the corresponding relationship between them. Through the model, the corresponding first roll gap variation ΔF1 and second roll gap variation ΔF2 when the rolling speed V changes within a certain range can be derived, thereby realizing precise control of the first roll gap F1 and the second roll gap F2. Specifically, by monitoring the change of the rolling speed in real time and combining the fitted mathematical relationship, the roll gap is automatically adjusted, so that the thickness of the pole piece is always maintained within the set standard deviation range. This technical solution effectively solves the problem of inconsistent pole piece thickness caused by changes in rolling speed, improves the consistency and stability of the pole piece thickness, and provides reliable protection for high-quality production of lithium battery pole pieces.

[0013] Preferably, the rolling speed V in S1 is greater than 0 m / min and less than 80 m / min.

[0014] A rolling speed greater than 0 m / min is a basic condition to ensure normal operation of the equipment, indicating that the rolling machine has started and is in a working state, rather than a shutdown or standby state. A rolling speed less than 80 m / min prevents over-compaction or under-compaction. In general, the operating range of the rolling speed is designed to be 0-80 m / min, which can meet the process requirements and equipment performance limitations of lithium battery pole piece production.

[0015] Preferably, the allowable deviation of the standard value in S1 is the standard value H ± 0.5 μm.

[0016] The standard value H of the pole piece thickness is strictly required to be controlled within an allowable deviation range, i.e. the standard value ±0.5 μm. This precise thickness control range ensures that the pole piece can achieve stable thickness requirements during the manufacturing process, thereby meeting the design performance and quality standards of lithium batteries.

[0017] Preferably, the data collected in S2 is more than five groups.

[0018] More than five groups of data can enhance the reliability of the data, which is crucial for accurately fitting the relationship between the rolling speed V and the first roll gap F1 and the second roll gap F2. Only a small number of data points can lead to over-fitting of the model to a specific working condition, and cannot truly reflect the general law between variables.

[0019] Preferably, the relationship shown in S2 is F1 = aln(V) + b; F2 = cln(V) + d; wherein a, b, c and d are coefficients automatically generated in the fitting.

[0020] The two relationships clearly define the logarithmic relationship between the rolling speed V and the roll gap F. This logarithmic model can accurately characterize the dynamic nonlinear changes of the first roll gap F1 and the second roll gap F2 at different rolling speeds V, providing the necessary mathematical basis for further accurate calculation of the first roll gap change ΔF1 and the second roll gap change ΔF2.

[0021] Preferably, the degree of linear correlation of the relationship in S2 is represented by a correlation coefficient R 2 , which is greater than 0.99. 2

[0022] The correlation coefficient R 2 reveals the linear correlation between the rolling speed V and the roll gap F, and its value can reflect the accuracy of the fitted relationship and the model's ability to explain the data. R 2 A value greater than 0.99 indicates that the relationship between the rolling speed V and the roll gap F has a very high linear correlation, and this linear equation can accurately describe the dynamic adjustment process of the roll gap when the rolling speed changes, thereby significantly improving the reliability of the calculation results.

[0023] Preferably, with the rolling speed V = 10 m / min as the reference, one said first roll gap change ΔF1 and one said second roll gap change ΔF2 are calculated for each 10 m / min speed range.

[0024] ​Setting the speed variation range based on 10 m / min can ensure the uniformity and reliability of the speed interval division, and this segmented mode can effectively reduce the process parameter fluctuation problem caused by the sharp change of speed during the rolling process of the pole piece. By dividing the speed into intervals of 10 m / min, the corresponding first roll gap change amount ΔF1 and second roll gap change amount ΔF2 can be accurately calculated and set in each range, ensuring that the pole piece thickness always remains within the standard deviation range under different speed conditions.

[0025] Preferably, the data in S2 is imported into a program that can automatically adjust the first roll gap F1 and the second roll gap F2 when the rolling speed V changes.

[0026] The program can eliminate the tediousness of manual operation and realize automatic adjustment of the first roll gap F1 and the second roll gap F2, significantly improving the automation and intelligence level of equipment operation. This automatic control not only reduces the error and lag caused by manual operation, but also makes the rolling process more efficiently adapt to the dynamic changes of the rolling speed V, further optimizing the consistency and stability of the pole piece thickness.

[0027] The beneficial effects of the present application are:

[0028] (1) In the present application, automatic adjustment of the roll gap according to the change of the rolling speed can avoid the problem of large thickness fluctuation in the process of speed change such as low-speed roll change and abnormal stop in the rolling production, improving the consistency of the pole piece rolling thickness.

[0029] (2) In the present application, under the condition of controlling the thickness at the standard value, through the fitting of the relationship between the rolling speed and the roll gap, the program automatically adjusts the roll gap according to the theoretical set value according to the speed change, avoiding the inaccuracy and untimeliness of manually adjusting the roll gap to control the thickness.

[0030] (3) The present application realizes automatic adjustment of the roll gap to control the thickness according to the change of the rolling speed of the rolling machine within the normal production speed range, greatly reducing manual operation, improving the automation and intelligence of equipment production, improving production efficiency, improving the quality of pole piece production, and significantly reducing the problems and scrap caused by abnormal thickness in the subsequent cutting process.

[0031] (4) The present application has simple implementation process, convenient operation, strong applicability, strong implementability, and does not need to increase manpower, material resources and equipment hardware facilities. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to make the technical solutions in the embodiments of the present application clearer, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0033] Figure 1 A curve graph of the relationship between the rolling speed and the roll gap;

[0034] Figure 2 A moving graph of the real-time rolling thickness and the rolling speed before using the automatic roll gap program;

[0035] Figure 3 A moving graph of the real-time rolling thickness and the rolling speed after using the automatic roll gap program. DETAILED DESCRIPTION

[0036] At present, the control of the thickness of the pole piece in the rolling process is mainly realized by scanning the thickness after the rolling of the roller, and the production personnel adjusts the roll gap control thickness according to the thickness displayed by the thickness gauge. However, in the actual production process, the thickness consistency will be obviously poor during the high-speed to low-speed process of the roll changing process, the low-speed to high-speed process after the roll changing process, and the acceleration and deceleration process of adjusting the rolling speed during other processing abnormalities. The production personnel cannot timely adjust the roll gap before and after these processes, which leads to the thickness abnormalities, causes the rejection of the pole piece thickness, and leads to the rejection of the cutting roll misalignment due to the poor thickness consistency of the pole piece. The present application can effectively solve this problem by studying the relationship between the rolling speed and the rolling thickness, and automatically adjusting the thickness by linking the rolling speed and the roll gap.

[0037] The thickness gauge can be used to measure the thickness of the pole piece on line, and output the measurement in the form of an electrical signal. The electrical signal is input to the display and the automatic thickness control system to realize the automatic thickness control of the plate thickness. At present, the common thickness gauges include four kinds of γ-ray, β-ray, x-ray and isotope ray.

[0038] Embodiment 1:

[0039] The rolling speed used in the normal production process of the 104Ah battery positive electrode rolling process is in the range of 0-80 m / min, wherein 0-30 m / min is the low-speed stage, the low-speed stage is the roll changing and processing abnormality traction process; 50-80 m / min is the high-speed stage, and the high-speed stage is the normal rolling production process.

[0040] The standard thickness of the positive electrode sheet of the 104Ah battery is set to 166μm, and the allowable deviation of the standard value is 166±0.5μm. Based on the rolling speed V=10m / min, the second roll gap and the first roll gap are adjusted until the thickness gauge shows that the electrode sheet thickness is stable within the standard value H=166±0.5μm. The first roll gap F1 and the second roll gap F2 at this time are recorded.

[0041] Using the same method, at rolling speeds V = 20, 30, 40, 50, 60, 70 and 80 m / min, the second roll gap and the first roll gap were adjusted until the thickness gauge showed that the electrode thickness was stable within the standard value H = 166 ± 0.5 μm. The first roll gap F1 and the second roll gap F2 corresponding to each rolling speed V were recorded. The data records are shown in Table 1.

[0042]

[0043]

[0044] Table 1. Roller speed and roll gap record table

[0045] Based on the standard thickness specifications of the 104Ah battery electrode sheets in Table 1, curve fitting was performed on the relationship between the rolling speed V and the first roll gap F1, and between the rolling speed V and the second roll gap F2, to obtain... Figure 1 The relational expression in the text. For example... Figure 1 As shown, the relationship between the rolling speed V and the first roll gap F1 is F1=-74.32ln(V)+437.01, and the correlation coefficient R of this relationship is... 2 The value is 0.993; the relationship between the rolling speed V and the second roll gap F2 is F2=-74.75ln(V)+416.82, and the correlation coefficient R of this relationship is 0.993. 2 It is 0.9919.

[0046] Based on the relationship between rolling speed and roll gap, the first roll gap change ΔF1 corresponding to the speed ranges of 10-20, 20-30, 20-40, 50-60, 60-70, and 70-80 m / min during normal rolling production of the 104Ah model electrode is 55, 35, 14, 20, 18, 6, and 2 μm, respectively; the second roll gap change ΔF2 is 56, 35, 12, 23, 17, 6, and 2 μm, respectively.

[0047] like Figure 2As shown, before using the method of the present application, when the rolling speed is reduced from a high speed of 80 m / min to 30 m / min and 0 m / min, the thickness of the pole piece fluctuates greatly and is far below the standard value H = 166 ± 0.5 μm due to the inability to adjust the roll gap in real time. After using the method of the present application, the roll gap is adjusted in real time according to the theoretical target set value with the change in speed during the start-up production, the gradual increase of the rolling speed from 0 to a high speed of 80 m / min, and the speed reduction from 80 m / min to 30 m / min during the roll change process. As shown, the pole piece rolling thickness during the acceleration and deceleration process is within the standard specification of 166 ± 0.5 μm, and the thickness consistency of the pole piece in each sub-zone does not fluctuate significantly. Figure 3 As shown, the pole piece rolling thickness during the acceleration and deceleration process is within the standard specification of 166 ± 0.5 μm, and the thickness consistency of the pole piece in each sub-zone does not fluctuate significantly.

[0048] Example 2

[0049] The present application provides that the rolling speed V, the first roll gap change amount ΔF1, and the second roll gap change amount ΔF2 are introduced into the program. The program can adjust the first roll gap F1 and the second roll gap F2 through the first roll gap change amount ΔF1 and the second roll gap change amount ΔF2, respectively, according to the range interval in which the current rolling speed V is located, to ensure that the thickness of the pole piece is within the standard value H = 166 ± 0.5 μm. In this way, the problem of abnormal rolling thickness caused by the high and low speed switching during the roll change process and the non-timely repeated adjustment of the roll gap is solved.

[0050] The data results of the above examples can show that the method of the present application for automatically improving the thickness consistency of the pole piece by linking the rolling speed and the roll gap improves the production quality of the pole piece, significantly reduces the problems and scrap caused by abnormal thickness of the pole piece in the subsequent cutting process, greatly reduces manual operation, and improves the automation and intelligence of the equipment production.

[0051] The above embodiments of the present application are described in detail, and the above examples are only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation and application range will be changed, and the above description should not be understood as a limitation of the present application.

Claims

1. A method for adjusting the roll gap based on roll pressing speed, characterized in that, Includes the following steps: S1: Set the standard value H of the electrode thickness, the allowable deviation of the standard value and the rolling speed V. Adjust the first roll gap and the second roll gap so that the electrode thickness is within the allowable deviation of the standard value. Record the first roll gap and the second roll gap at this time. Record the first roll gap as F1 and the second roll gap as F2. S2: Repeat S1, collect multiple sets of data on the roller pressing speed V, the first roller gap F1, and the second roller gap F2, and fit the relationship between the roller pressing speed V and the first roller gap F1 and the relationship between the roller pressing speed V and the second roller gap F2 respectively; S3: Based on the relationship in S2, the first roll gap F1 and the second roll gap F2 corresponding to different roll pressing speeds V are obtained, thereby obtaining the change amount ΔF1 of the first roll gap and the change amount ΔF2 of the second roll gap when the roll pressing speed V changes within any speed range. S4: Based on the first roll gap change ΔF1 and the second roll gap change ΔF2 in S3, adjust the first roll gap F1 and the second roll gap F2 when the rolling speed V changes to ensure that the electrode thickness is within the standard deviation range.

2. The method for adjusting the roll gap based on the roll pressing speed according to claim 1, characterized in that, The roller pressing speed V mentioned in S1 is greater than 0 m / min and less than 80 m / min.

3. The method for adjusting the roll gap based on roll pressing speed as described in claim 1, characterized in that, The permissible deviation of the standard value in S1 is the standard value H ± 0.5 μm.

4. The method for adjusting the roll gap based on the roll pressing speed according to claim 1, characterized in that, More than five sets of data were collected in S2.

5. The method for adjusting the roll gap based on roll pressing speed according to claim 1, characterized in that, The relationships shown in S2 are F1 = alan(V) + b; F2 = cln(V) + d; where a, b, c, and d are coefficients automatically generated during the fitting process.

6. The method for adjusting the roll gap based on the roll pressing speed according to claim 1, characterized in that, The degree of linear correlation in the relationship described in S2 is expressed by the correlation coefficient R. 2 This indicates that the correlation coefficient R 2 Greater than 0.

99.

7. The method for adjusting the roll gap based on roll pressing speed according to claim 1, characterized in that, Based on a roll pressing speed of V = 10 m / min, calculate a first roll gap change ΔF1 and a second roll gap change ΔF2 for every 10 m / min speed range.

8. The method for adjusting the roll gap based on the roll pressing speed according to claim 1, characterized in that, The data described in S2 is imported into the program, which can automatically adjust the first roll gap F1 and the second roll gap F2 when the roll speed V changes.

Images