Method for controlling thinning size and width of pole piece in coating process of lithium ion battery

Abstract

The invention discloses a method for controlling the thinning size and width of a pole piece in a coating process of a lithium ion battery. The method comprises the following steps: identifying influence factors influencing the thinning size and width of the pole piece in the coating process; according to the attribute of each influence factor, outputting a horizontal value range of each influence factor; outputting an experiment combination scheme according to the level value range of each influence factor; performing a coating experiment according to the experiment combination scheme, and collecting coating experiment data; and outputting pole piece coating parameters according to the obtained coating experiment data in combination with a coating target value. According to the method, the main influence factors influencing the thinning size and width in the coating process are identified, the influence of different main influence factors on the thinning size and width is analyzed, and the main influence factors are controlled and designed, so that the pole piece thinning area produced in the coating process is predicted, analyzed and judged in advance, and the working efficiency is improved. And material scrapping and acceptance loss caused by experience exploration are reduced, and a scientific scheme is adopted to design and output quantitative control methods and measures.

Description

Technical Field

[0001] The invention relates to the technical field of pole piece coating parameter control, and in particular to a method for controlling the thinning size and width of a pole piece in a lithium ion battery coating process. Background Art

[0002] The lithium battery pole piece is evenly coated on the current collector by the slurry sprayed from the die head of the coating machine. The edge of the coating area of ​​the pole piece has a high or low thickness due to the different contact angles between the liquid and the foil. It is divided into a coating area and an edge thinning area on both sides of the coating area. In order to control whether the size of the edge thinning area meets the production requirements of lithium batteries, the chamfer of the coating gasket will be designed differently to reduce the edge thickening situation.

[0003] At present, the control of the edge thinning area of ​​the lithium battery is achieved by designing the horizontal and vertical chamfers of the coated gasket with different sizes. However, this method requires experimental verification of chamfers with different configurations, and cannot accurately reflect the edge thinning amount and thinning width. Repeated experimental verifications have resulted in a large number of pole pieces being scrapped, and it is impossible to form accurate quantitative data guidance. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings and defects of the prior art and to provide a method for controlling the thinning size and width of a pole piece in a lithium ion battery coating process.

[0005] A method for controlling the thinning size and width of a pole piece in a lithium-ion battery coating process, comprising:

[0006] S1. Identify the factors that affect the size and width of the electrode thinning during the coating process;

[0007] S2. Output the level value range of each influencing factor according to the attributes of each influencing factor;

[0008] S3. Output a list of experimental combination schemes according to the level value range of each influencing factor;

[0009] S4. Perform coating experiments according to the experimental combination scheme list and collect coating experiment data;

[0010] S5. Output the electrode coating parameters based on the obtained coating experimental data and the coating target value.

[0011] There are multiple influencing factors, and the multiple influencing factors are independent of each other and do not affect each other.

[0012] The influencing factors include surface density, coating speed, gasket transverse opening and gasket longitudinal opening.

[0013] The horizontal value range of the surface density is 8.48-12.7 mg / cm2 .

[0014] Wherein, the average value range of the coating speed is 10 to 20 m / min.

[0015] Wherein, the horizontal value range of the transverse opening of the gasket is 2 to 8 mm.

[0016] Wherein, the horizontal value range of the longitudinal opening of the gasket is 2 to 8 mm.

[0017] Among them, the influencing factors are positively correlated with the thinning size and width of the pole piece.

[0018] Among them, the coating experiment data includes data on single-sided thinning percentage, single-sided thinning amount and thinning width. The single-sided thinning percentage is the ratio of the thickness of the edge of the pole piece to the average thickness of the middle material area of ​​the pole piece, which is used to directly reflect the thinning ability.

[0019] Wherein, in the step S5, the response optimizer in the software Minitab is used for processing, and the response optimizer outputs the parameters of the electrode coating according to the obtained coating experimental data and the coating target value.

[0020] The method for controlling the thinning size and width of the pole piece in the coating process of a lithium-ion battery of the present invention identifies the main influencing factors affecting the thinning size and width in the coating process, analyzes the influence of different main influencing factors on the thinning size and width, and performs control design on the main influencing factors, so as to achieve early prediction and analysis and judgment of the pole piece thinning area output in the coating process, reduce material scrapping and acceptance losses caused by empirical exploration, and adopt scientific scheme design to output quantitative control methods and measures. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a flow chart of a method for controlling the thinning size and width of a pole piece in a lithium-ion battery coating process.

[0022] Figure 2 It is a contour diagram of the thinning width, the longitudinal opening and the transverse opening of the present invention.

[0023] Figure 3 It is a contour diagram of the thinning percentage and the longitudinal opening and the transverse opening of the present invention.

[0024] Figure 4 It is a schematic diagram of a DOE experimental plate response optimizer using the software Minitab of the present invention. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] The present invention provides a method for controlling the thinning size and width of a pole piece in a lithium-ion battery coating process, comprising:

[0027] S1. Identify the factors that affect the size and width of the electrode thinning during the coating process;

[0028] S2. Output the level value range of each influencing factor according to the attributes of each influencing factor;

[0029] S3. Output a list of experimental combination schemes according to the level value range of each influencing factor;

[0030] S4. Perform coating experiments according to the experimental combination scheme list and collect coating experiment data;

[0031] S5. Output the electrode coating parameters based on the obtained coating experimental data and the coating target value.

[0032] In the above step S2, the attributes of each influencing factor include the application scope and product and equipment capability limit range corresponding to each influencing factor, and each influencing factor has a selectable range value, including a high level value and a low level value.

[0033] There are multiple influencing factors, and the multiple influencing factors are independent of each other and do not affect each other.

[0034] Preferably, based on the general situation of coating, in the embodiment of the present application, the influencing factors determined include surface density, coating speed, gasket transverse opening and gasket longitudinal opening, that is, four main influencing factors.

[0035] The horizontal value range of the surface density is 8.48-12.7 mg / cm 2 The average value range of the coating speed is 10-20 m / min. The horizontal value range of the lateral opening of the gasket is 2-8 mm. The horizontal value range of the longitudinal opening of the gasket is 2-8 mm. The influencing factors are positively correlated with the thinning size and width of the pole piece.

[0036] The coating experimental data includes single-sided thinning percentage, single-sided thinning amount and thinning width data. The single-sided thinning percentage is the ratio of the thickness of the edge of the pole piece to the average thickness of the middle material area of ​​the pole piece, which is used to directly reflect the thinning ability. In the present invention, since the surface density is used as an influencing factor, different surface densities are positively correlated with thickness, it is not accurate to look at the edge thinning amount alone, so the experimental data includes the thinning width.

[0037] Based on the experimental data, such as the data on the single-sided thinning amount and thinning width of the electrode, combined with the target values ​​of the single-sided thinning amount and width of the electrode, the parameters of the electrode coating, that is, the control parameters, can be obtained. Then, according to the control parameters, the realization of the target values ​​of the single-sided thinning amount and thinning width of the electrode can be controlled.

[0038] In the embodiment of the present invention, a DOE experimental method is used to identify the factors affecting the single-side thinning size and thinning width, and corresponding technical guidance is given through quantitative calculation.

[0039] In step S3, the software Minitab is used to create a list of experimental combination schemes, as shown in Table 1:

[0040] Table 1

[0041]

[0042] According to the main influencing factor parameters specified in the experimental combination plan list in step S3, the coating experiment is carried out, the thinning amount and width data in each group of experiments are collected, and the experimental combination plan table is output. As shown in Table 2:

[0043] Table 2

[0044]

[0045] Wherein, in the step S5, the response optimizer in the software Minitab is used for processing, and the response optimizer outputs the parameters of the electrode coating according to the obtained coating experimental data and the coating target value.

[0046] See also Figure 2 as well as Figure 3 As shown, in the specific implementation of data processing, the corresponding contour map is output to predict the corresponding parameters. The contour map is to screen out the best value of the influencing factor through the position of the intersection of the horizontal and vertical coordinate axes, so that the best value of the factor can be found through the regression equation and the contour map to obtain the best design solution.

[0047] See also Figure 2 As shown, it shows that under the same conditions, the orthogonal effects of the chamfering horizontal and vertical openings on the thinning width. When the coating gasket chamfer adopts a horizontal opening of 2.09910mm*longitudinal 2.09479mm, the predicted thinning width is 8.61295mm. Figure 2 As shown, it indicates that under the same conditions, the orthogonal effects of the chamfer's transverse and longitudinal openings on the thinning percentage, when the coated gasket chamfer adopts a transverse opening of 3.23616mm*longitudinal 3.70960mm, the predicted thinning percentage is 85.4098%.

[0048] See also Figure 4As shown, according to the input target expectation and design surface density value, the transverse and longitudinal chamfer design is output, the expected target of single-sided thinning percentage is 0.8541, the surface density design value is 10.590, within the high level value range and the low level value range, the output transverse opening is 3.8091, and the longitudinal opening is 2.0, both within the corresponding high level value range and the low level value range.

[0049] The method for controlling the thinning size and width of the lithium-ion battery coating process in the embodiment of the present invention can accurately reflect the main influencing factors affecting the thinning amount and thinning width by adopting a scientific experimental verification method, provide accurate tooling design parameters for the design of the electrode coating gasket, reduce experimental scrapping due to experience exploration, reduce the number of experiments, and quantify the output of the electrode thinning status.

[0050] The method for controlling the thinning size and width of the pole piece in the coating process of a lithium-ion battery of the present invention identifies the main influencing factors affecting the thinning size and width in the coating process, analyzes the influence of different main influencing factors on the thinning size and width, and performs control design on the main influencing factors, so as to achieve early prediction and analysis and judgment of the pole piece thinning area output in the coating process, reduce material scrapping and acceptance losses caused by empirical exploration, and adopt scientific scheme design to output quantitative control methods and measures.

[0051] The basic principles and main features of the present invention and the advantages of the present invention are shown and described above. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention.

[0052] Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is therefore intended that all changes falling within the meaning and range of equivalent elements of the claims are included in the present invention.

[0053] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for controlling the thinning size and width of a pole piece in a lithium-ion battery coating process, characterized in that: include: S1. Identify the factors that affect the size and width of the electrode thinning during the coating process; S2. Output the level value range of each influencing factor according to the attributes of each influencing factor; S3. Output a list of experimental combination schemes according to the level value range of each influencing factor; S4. Perform coating experiments according to the experimental combination scheme list and collect coating experiment data; S5. Output the electrode coating parameters based on the obtained coating experimental data and the coating target value.

2. The method for controlling the thinning size and width of the electrode sheet in the coating process of a lithium-ion battery according to claim 1, characterized in that: There are multiple influencing factors, and the multiple influencing factors are independent of each other and do not affect each other.

3. The method for controlling the thinning size and width of the electrode sheet in the coating process of a lithium-ion battery according to claim 2, characterized in that: The influencing factors include surface density, coating speed, gasket transverse opening and gasket longitudinal opening.

4. The method for controlling the thinning size and width of the electrode sheet in the coating process of a lithium-ion battery according to claim 3, characterized in that: The horizontal value range of the surface density is 8.48 to 12.7 mg / cm 2 .

5. The method for controlling the thinning size and width of the electrode sheet in the coating process of a lithium-ion battery according to claim 3, characterized in that: The average value range of the coating speed is 10 to 20 m / min.

6. The method for controlling the thinning size and width of the electrode sheet in the coating process of a lithium-ion battery according to claim 3, characterized in that: The horizontal value range of the transverse opening of the gasket is 2 to 8 mm.

7. The method for controlling the thinning size and width of the electrode sheet in the coating process of a lithium-ion battery according to claim 3, characterized in that: The horizontal value range of the longitudinal opening of the gasket is 2 to 8 mm.

8. The method for controlling the thinning size and width of the electrode sheet in the coating process of a lithium-ion battery according to claim 3, characterized in that: The influencing factors are positively correlated with the thinning size and width of the pole piece.

9. The method for controlling the thinning size and width of the electrode sheet in the coating process of a lithium-ion battery according to claim 1, characterized in that: The coating experiment data include single-sided thinning percentage, single-sided thinning amount and thinning width data. The single-sided thinning percentage is the ratio of the electrode edge thickness to the average thickness of the electrode middle material area, which is used to directly reflect the thinning ability.

10. The method for controlling the thinning size and width of the electrode sheet in the coating process of a lithium-ion battery according to claim 1, characterized in that: In the step S5, the response optimizer in the software Minitab is used for processing, and the response optimizer outputs the parameters of the electrode coating according to the obtained coating experimental data and the coating target value.

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