Battery aluminum foil preparation process
By adjusting the oil and ironing roller parameters in battery aluminum foil production, especially the flat rolls of the fourth rolling pass have no convexity and gradually increased winding tension and pressure, the surface defects of the aluminum foil are solved and the product quality is improved.
Patent Information
- Application Number
- CN202510285967.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-12
- Publication Date
- 2025-07-11
AI Technical Summary
During the production process of battery aluminum foil, uneven heat caused by calendering leads to changes in the rolling roll, forming defects such as bubbles, edges and tension lines on the surface of the aluminum foil, and the large winding tension is difficult to accurately regulate.
By adjusting the oil and ironing roller parameters, especially the fourth rolling pass uses a flat roll without convexity, the winding tension and ironing roller pressure gradually increase, specifically, gradually increase within the range of 6.0-9.0 kg/mm² and 1.0-6.0 bar.
It effectively solves the problems of string bubbles, bright lines, tension lines and edges on the surface of aluminum foil, and improves the surface flatness and quality of aluminum foil.
Smart Images
Figure CN120286499A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of battery aluminum foils, and particularly relates to a preparation process of battery aluminum foils. Background Art
[0002] With the gradual phasing out of the subsidy policy for pure electric new energy vehicles, the production cost and technological progress level of batteries have become the basis for calculating subsidies. Energy consumption levels, vehicle cruising ranges, the ratio of battery weight to vehicle weight, battery performance levels, etc. are set as access thresholds, and factors such as battery capacity and energy density levels have become new standards for vehicle subsidies. Therefore, domestic power battery manufacturers have launched high-energy density power batteries, and the production focus has gradually shifted in this direction.
[0003] The production process of battery aluminum foils involves multiple complex technological steps, such as alloy melting and casting, homogenization, casting and rolling, cold rolling, intermediate annealing, foil rolling, etc. Each process is closely linked, and problems in any link will affect the yield rate of the final product.
[0004] The main problems it currently faces include: during the rolling process, the deformation heat and frictional heat are uneven on the foil surface. The uneven heat causes slight changes in the rolling rolls, which are reflected on the aluminum foil in the middle of the rolls, resulting in the problem of string bubbles on the aluminum foil surface. It is impossible to accurately control the heat in the rolling area, and improvement can only be carried out after rolling is completed. Therefore, a large coiling tension is used to flatten the aluminum foil to form a tension leveling and straightening effect; however, increasing the coiling tension will cause a series of other problems, such as the large coiling tension will make the electrical signals feedback by the plate shape roll of the rolling mill inaccurate, easily resulting in defects in plate shape. At the same time, when the aluminum foil is formed under a large coiling tension, defects such as ridges and tension lines will occur during the stress release process. Summary of the Invention
[0005] The purpose of the present invention is to overcome the defects existing in the prior art and provide a preparation process of battery aluminum foils, which can effectively solve problems such as plate shape, ridges, and tension lines by adjusting the oil product and the parameters of the flattening roll.
[0006] To achieve the above purpose, the technical solution of the present invention is to design a preparation process of battery aluminum foils, and its preparation steps are as follows: S1: The aluminum foil blank is subjected to foil rolling to obtain an aluminum strip; wherein, the foil rolling sequentially includes a first rolling pass and a second rolling pass; S2: The aluminum strip is subjected to intermediate rolling to obtain an aluminum coil; wherein, the intermediate rolling includes a third rolling pass; S3: The aluminum coil is subjected to finish rolling to obtain a finished aluminum coil, and the finish rolling includes a fourth rolling pass. During the rolling process, the coiling tension and the pressure of the flattening roll gradually increase; S4: After the finished aluminum coil is taken off the production line, it is slit and precision cut to obtain battery aluminum foils; Among them, the flattening roll in the fourth rolling pass uses a flat roll without convexity, and the coiling tension in the fourth rolling pass is 6.0 - 9.0 kg / mm²; the flat roll pressure in the fourth rolling pass is 1.0 - 6.0 bar.
[0007] Further, the coiling tension in the fourth rolling pass is 6.5 - 8.0 kg / mm²; the flat roll pressure in the fourth rolling pass is 1.8 - 4.6 bar.
[0008] Preferably, in the fourth rolling pass process, the coiling tension of the flat roll increases from 6.5 kg / mm² to 8.0 kg / mm² at a rate of 0.08 - 0.12 kg / mm² per ten thousand meters; the flat roll pressure increases from 1.8 bar to 4.6 bar at a rate of 0.1 - 0.3 bar per ten thousand meters.
[0009] Most preferably, in the fourth rolling pass process, the coiling tension of the flat roll increases from 6.5 kg / mm² to 8.0 kg / mm² at a rate of 0.1 kg / mm² per ten thousand meters; the flat roll pressure increases from 1.8 bar to 4.6 bar at a rate of 0.2 bar per ten thousand meters.
[0010] Further, the rolling parameters of steps S1 - S4 are as follows: 。
[0011] Among them, A1 represents type A rolls generally used in the rough rolling pass; B1 and B2 represent type B rolls generally used in the intermediate rolling pass, and C1 represents type C rolls generally used in the finish rolling pass; Preferably, the parameters of the rolls specifically used for A1, B1, B2, and C1 are as shown in the following table: 。
[0012] Preferably, the rolling parameters of steps S1 - S4 are as follows: 。
[0013] Among them, during the rolling process of pass P4, the flattening roll uses a flat roll without convexity, and the coiling tension increases from 6.5 kg / mm² to 8.0 kg / mm² at a rate of 0.1 kg / mm² per ten thousand meters; the flattening roll pressure increases from 1.8 bar to 4.6 bar at a rate of 0.2 bar per ten thousand meters.
[0014] Further, the thicknesses of the aluminum foil at the inlet and outlet in the first rolling pass process are 200 - 240 μm and 100 - 110 μm respectively; the thicknesses of the aluminum foil at the inlet and outlet in the second rolling pass process are 100 - 110 μm and 40 - 50 μm respectively; the thicknesses of the aluminum foil at the inlet and outlet in the third rolling pass process are 40 - 50 μm and 15 - 25 μm respectively; the thicknesses of the aluminum foil at the inlet and outlet in the fourth rolling pass process are 15 - 25 μm and 10 - 15 μm respectively.
[0015] Preferably, the thicknesses of the aluminum foil at the inlet and outlet in the first rolling pass process are 220 μm and 105 μm respectively; the thicknesses of the aluminum foil at the inlet and outlet in the second rolling pass process are 105 μm and 46 μm respectively; the thicknesses of the aluminum foil at the inlet and outlet in the third rolling pass process are 46 μm and 21.5 μm respectively; the thicknesses of the aluminum foil at the inlet and outlet in the fourth rolling pass process are 21.5 μm and 13 μm respectively.
[0016] Further, the reduction ratio of the first rolling pass is 50 - 55%, the reduction ratio of the second rolling pass is 54 - 58%, the reduction ratio of the third rolling pass is 50 - 55%, and the reduction ratio of the fourth rolling pass is 38 - 42%.
[0017] Preferably, the reduction ratio of the first rolling pass is 52.27%, the reduction ratio of the second rolling pass is 56.19%, the reduction ratio of the third rolling pass is 53.26%, and the reduction ratio of the fourth rolling pass is 39.53%.
[0018] Further, the viscosity of the rolling oil is 1.80 - 2.30 mm² / s.
[0019] Further, the rolling oil used is 90# oil. Preferably, the rolling oil used is the 90# base oil of Cangzhou Huahai Refining & Chemical Industry.
[0020] Preferably, the viscosity of the rolling oil is 1.90 - 2.10 mm² / s; most preferably, the viscosity of the rolling oil is 2.0 mm² / s.
[0021] The flattening rollers in the first rolling pass, the second rolling pass, and the third rolling pass adopt flattening rollers with a convexity of 20‰mm.
[0022] The advantages and beneficial effects of the present invention are as follows: The preparation process of the present invention is quite different from the conventional aluminum foil production and processing process. The preparation process of the present invention can effectively alleviate the influence of large coiling tension through the rolling oil product, the convexity of the flattening roller, and pressure adjustment. Description of the Drawings
[0023] Figure 1It is a diagram of the aluminum foil product prepared in Example 1; Figure 2 It is a diagram of the aluminum foil product prepared in Comparative Example 1; Figure 3 It is a diagram of the aluminum foil product prepared in Comparative Example 2; Figure 4 It is a diagram of the aluminum foil product prepared in Comparative Example 3; Figure 5 It is a diagram of the aluminum foil product prepared in Comparative Example 4; Figure 6 It is a diagram of the aluminum foil product prepared in Comparative Example 5; Figure 7 It is a diagram of the aluminum foil product prepared in Comparative Example 6. Detailed implementation manners
[0024] The following combines the accompanying drawings and examples to further describe the detailed implementation manners of the present invention. The following examples are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present invention. Examples
[0025] A preparation process for battery aluminum foil, and its preparation steps are as follows: S1: Perform foil rolling on the aluminum foil blank to obtain an aluminum strip; among them, the foil rolling sequentially includes a first rolling pass and a second rolling pass; S2: Perform medium rolling on the aluminum strip to obtain an aluminum coil; among them, the medium rolling includes a third rolling pass; S3: Perform finish rolling on the aluminum coil to obtain a finished aluminum coil, and the finish rolling includes a fourth rolling pass, and the coiling tension and the pressure of the flattening roll gradually increase during the rolling process; S4: After the finished aluminum coil is taken off the production line, perform slitting and precision cutting to obtain the battery aluminum foil.
[0026] The rolling oil uses the 90# base oil of Cangzhou Huahai Refining and Chemical Industry, and its standard viscosity is 1.80 - 2.30 mm² / s, and the actual value is about 2.02 mm² / s.
[0027] The flattening rolls in the first rolling pass, the second rolling pass, and the third rolling pass use flattening rolls with a convexity of 20‰ mm; The rolling parameters of steps S1 - S4 are as follows: .
[0028] Among them, during the process of rolling the P4 pass, the flattening roll uses a flat roll without convexity, and the coiling tension increases from 6.5 kg / mm² at a rate of increasing by 0.1 kg / mm² per 10,000 meters to 8.0 kg / mm²; the pressure of the flattening roll increases from 1.8 bar at a rate of increasing by 0.2 bar per 10,000 meters to 4.6 bar.
[0029] The product drawing of the battery aluminum foil prepared by the process of Example 1 is as Figure 1 shown. It can be seen through Figure 1 that the surface of the battery aluminum foil prepared by the above process parameters is flat, without defects such as bubble stringing and bright lines.
[0030] Comparative Example 1: A process for preparing battery aluminum foil, the preparation steps are as follows: S1: The aluminum foil blank is subjected to foil rolling to obtain an aluminum strip; wherein, the foil rolling sequentially includes a first rolling pass and a second rolling pass; S2: The aluminum strip is subjected to intermediate rolling to obtain an aluminum coil; wherein, the intermediate rolling includes a third rolling pass; S3: The aluminum coil is subjected to finish rolling to obtain a finished aluminum coil, and the finish rolling includes a fourth rolling pass, and the coiling tension and the pressure of the flattening roll gradually increase during the rolling process; S4: After the finished aluminum coil is taken off the production line, it is slit and precision cut to obtain the battery aluminum foil.
[0031] The rolling oil used is the 80# base oil of Fushun Zhongtai Chemical Co., Ltd. (Xintai), and its standard viscosity is 1.6 - 1.9 mm² / s, and the actual is about 1.7 mm² / s.
[0032] The flattening rolls in the first rolling pass, the second rolling pass, and the third rolling pass adopt flattening rolls with a convexity of 20‰ mm; The rolling parameters of the steps S1 - S4 are as follows: .
[0033] Among them, during the rolling of the P4 pass, the flattening roll uses a flat roll without convexity, and the coiling tension increases from 6.5 kg / mm² at a rate of increasing by 0.1 kg / mm² per 10,000 meters to 8.0 kg / mm²; the pressure of the flattening roll increases from 1.8 bar at a rate of increasing by 0.2 bar per 10,000 meters to 4.6 bar.
[0034] For the product of the battery aluminum foil prepared by the process of Comparative Example 1, the bubble stringing situation is good, but bright line defects appear on the surface.
[0035] Comparative Example 2: A process for preparing battery aluminum foil, the preparation steps are as follows: S1: The aluminum foil blank is subjected to foil rolling to obtain an aluminum strip; wherein, the foil rolling sequentially includes a first rolling pass and a second rolling pass; S2: The aluminum strip is subjected to intermediate rolling to obtain an aluminum coil; wherein, the intermediate rolling includes a third rolling pass; S3: Carry out finish rolling on the aluminum coil to obtain a finished aluminum coil. The finish rolling includes a fourth rolling pass, and during the rolling process, the coiling tension and the pressure of the flattening roll gradually increase; S4: After taking the finished aluminum coil offline, perform slitting and precision cutting to obtain the battery aluminum foil.
[0036] The rolling oil uses the 90# base oil of Cangzhou Huahai Refining & Chemical Industry. Its standard viscosity is 1.80 - 2.30 mm² / s, and the actual viscosity is about 2.02 mm² / s.
[0037] During the processes of the first rolling pass, the second rolling pass, the third rolling pass, and the fourth rolling pass, a flattening roll with a convexity of 20‰ mm is used.
[0038] The rolling parameters of steps S1 - S4 are as follows: 。
[0039] Among them, during the rolling of the P4 pass, the coiling tension increases from 6.5 kg / mm² at a rate of increasing 0.1 kg / mm² per ten thousand meters to 8.0 kg / mm²; the pressure of the flattening roll increases from 1.8 bar at a rate of increasing 0.2 bar per ten thousand meters to 4.6 bar; For the product of the battery aluminum foil prepared by the process of Comparative Example 2, the stringing situation is good, but there are tension lines and ridges at the edge of the aluminum foil roll.
[0040] Comparative Example 3: A preparation process for battery aluminum foil, and its preparation steps are as follows: S1: Carry out foil rolling on the aluminum foil blank to obtain an aluminum strip; among them, the foil rolling sequentially includes a first rolling pass and a second rolling pass; S2: Carry out medium rolling on the aluminum strip to obtain an aluminum coil; among them, the medium rolling includes a third rolling pass; S3: Carry out finish rolling on the aluminum coil to obtain a finished aluminum coil. The finish rolling includes a fourth rolling pass, and during the rolling process, the coiling tension and the pressure of the flattening roll gradually increase.
[0041] S4: After taking the finished aluminum coil offline, perform slitting and precision cutting to obtain the battery aluminum foil.
[0042] The rolling oil uses the 90# base oil of Cangzhou Huahai Refining & Chemical Industry. Its standard viscosity is 1.80 - 2.30 mm² / s, and the actual viscosity is about 2.02 mm² / s.
[0043] For the first rolling pass, the second rolling pass, and the third rolling pass, a flattening roll with a convexity of 20‰ mm is used; During the process of the P4 rolling pass, a flat roll without convexity is used for the flattening roll, and the coiling tension in the fourth rolling pass adopts a fixed value of 6.0 ± 0.2 kg / mm²; The rolling parameters of the steps S1 - S4 are as follows: .
[0044] The ironing roll pressure in the fourth rolling pass increases from 1.8 bar to 4.6 bar at a rate of increasing by 0.2 bar per ten thousand meters; For the product of the battery aluminum foil prepared by the process of Comparative Example 3, the series of bubbles is not improved.
[0045] Comparative Example 4: A preparation process of battery aluminum foil, and its preparation steps are as follows: S1: Perform foil rolling on the aluminum foil blank to obtain an aluminum strip; wherein, the foil rolling sequentially includes a first rolling pass and a second rolling pass; S2: Perform intermediate rolling on the aluminum strip to obtain an aluminum coil; wherein, the intermediate rolling includes a third rolling pass; S3: Perform finish rolling on the aluminum coil to obtain a finished aluminum coil, and the finish rolling includes a fourth rolling pass, and the coiling tension and the ironing roll pressure gradually increase during the rolling process.
[0046] S4: After the finished aluminum coil is taken off the production line, perform slitting and precision cutting to obtain the battery aluminum foil.
[0047] The rolling oil uses the 90# base oil of Cangzhou Huahai Refining & Chemical Industry, and its standard viscosity is 1.80 - 2.30 mm² / s, and the actual value is about 2.02 mm² / s.
[0048] The ironing rolls in the first rolling pass, the second rolling pass, and the third rolling pass use ironing rolls with a convexity of 20‰mm; During the process of rolling the P4 pass, a flat roll without convexity is used for the ironing roll, and the coiling tension in the fourth rolling pass adopts a fixed value of 8.0 ± 0.5 kg / mm²; The rolling parameters of the steps S1 - S4 are as follows: .
[0049] The ironing roll pressure in the fourth rolling pass increases from 1.8 bar to 4.6 bar at a rate of increasing by 0.2 bar per ten thousand meters; For the product of the battery aluminum foil prepared by the process of Comparative Example 4, the surface of the foil has ridges.
[0050] Comparative Example 5: A preparation process of battery aluminum foil, and its preparation steps are as follows: S1: Perform foil rolling on the aluminum foil blank to obtain an aluminum strip; wherein, the foil rolling sequentially includes a first rolling pass and a second rolling pass; S2: Perform intermediate rolling on the aluminum strip to obtain an aluminum coil; wherein, the intermediate rolling includes a third rolling pass; S3: Finish precision rolling the aluminum coil to obtain a finished aluminum coil. The precision rolling includes a fourth rolling pass, and during the rolling process, the coiling tension and the pressure of the flattening roll gradually increase.
[0051] S4: After taking the finished aluminum coil offline, perform slitting and precision cutting to obtain the battery aluminum foil.
[0052] The rolling oil uses the 90# base oil of Cangzhou Huahai Refining & Chemical Industry. Its standard viscosity is 1.80 - 2.30 mm² / s, and the actual viscosity is about 2.02 mm² / s.
[0053] The flattening rolls in the first rolling pass, the second rolling pass, and the third rolling pass use flattening rolls with a convexity of 20‰ mm. During the process of rolling the P4 pass, the flattening roll uses a flat roll without convexity. The coiling tension in the fourth rolling pass is 2.5 - 6 kg / mm², and the coiling tension increases from 2.5 kg / mm² at a rate of 0.1 kg / mm² per 10,000 meters to 6.0 kg / mm². 。
[0054] The pressure of the flattening roll in the fourth rolling pass increases from 1.8 bar at a rate of 0.2 bar per 10,000 meters to 4.6 bar. For the product of the battery aluminum foil prepared by the process of Comparative Example 5, there are string bubbles on the foil surface.
[0055] Comparative Example 6: A preparation process for battery aluminum foil, and its preparation steps are as follows: S1: Perform foil rolling on the aluminum foil blank to obtain an aluminum strip; among them, the foil rolling sequentially includes a first rolling pass and a second rolling pass. S2: Perform medium rolling on the aluminum strip to obtain an aluminum coil; among them, the medium rolling includes a third rolling pass. S3: Finish precision rolling the aluminum coil to obtain a finished aluminum coil. The precision rolling includes a fourth rolling pass, and during the rolling process, the coiling tension and the pressure of the flattening roll gradually increase.
[0056] S4: After taking the finished aluminum coil offline, perform slitting and precision cutting to obtain the battery aluminum foil.
[0057] The rolling oil uses the 90# base oil of Cangzhou Huahai Refining & Chemical Industry. Its standard viscosity is 1.80 - 2.30 mm² / s, and the actual viscosity is about 2.02 mm² / s.
[0058] The flattening rolls in the first rolling pass, the second rolling pass, and the third rolling pass use flattening rolls with a convexity of 20‰ mm. During the process of rolling the P4 pass, the flattening roll uses a flat roll without convexity. The ironing roll pressure in the fourth rolling pass is 2.4 bar.
[0059] The rolling parameters of the steps S1 - S4 are as follows: .
[0060] The coiling tension in the fourth rolling pass increases from 6.5 kg / mm² at a rate of 0.1 kg / mm² per 10,000 meters to 8.0 kg / mm²; For the product of the battery aluminum foil prepared by the process of Comparative Example 6, the bottom of the rolled coil is good, and the top has ridges.
[0061] The preparation process described in the present invention is very different from the conventional aluminum foil production and processing process. The preparation process described in the present invention can effectively alleviate the influence of large coiling tension through rolling oil products, ironing roll crown, and pressure adjustment.
[0062] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.
Claims
1. A preparation process for battery aluminum foil, characterized in that, The preparation steps are as follows: S1: Subject the aluminum foil blank to foil rolling to obtain an aluminum strip; wherein, the foil rolling sequentially includes a first rolling pass and a second rolling pass; S2: Subject the aluminum strip to intermediate rolling to obtain an aluminum coil; wherein, the intermediate rolling includes a third rolling pass; S3: Subject the aluminum coil to finish rolling to obtain a finished aluminum coil, and the finish rolling includes a fourth rolling pass, and the coiling tension and the pressure of the flattening roll gradually increase during the rolling process; S4: After the finished aluminum coil is taken off the production line, it is slit and precision cut to obtain battery aluminum foil.
2. The preparation process of the battery aluminum foil according to claim 1, characterized in that The flattening roll in the fourth rolling pass uses a flat roll without camber, and the coiling tension in the fourth rolling pass is 6.0 - 9.0 kg / mm²; the pressure of the flat roll in the fourth rolling pass is 1.0 - 6.0 bar.
3. A preparation process of battery aluminum foil according to claim 1, characterized in that, The coiling tension in the fourth rolling pass is 6.5 - 8.0 kg / mm²; the pressure of the flat roll in the fourth rolling pass is 1.8 - 4.6 bar.
4. The preparation process of battery aluminum foil according to claim 1, characterized in that, In the fourth rolling pass process, the coiling tension of the flat roll increases from 6.5 kg / mm² by 0.08 - 0.12 kg / mm² per 10,000 meters to 8.0 kg / mm²; the pressure of the flat roll in the fourth rolling pass process increases from 1.8 bar at a rate of 0.1 - 0.3 bar per 10,000 meters to 4.6 bar.
5. A preparation process for battery aluminum foil according to claim 1, characterized in that, The rolling parameters of the steps S1 - S4 are as follows: 。 6. A process for preparing battery aluminum foil according to claim 5, characterized in that, In the first rolling pass process, the thicknesses of the aluminum foil at the inlet and outlet are 200 - 240 microns and 100 - 110 microns respectively; in the second rolling pass process, the thicknesses of the aluminum foil at the inlet and outlet are 100 - 110 microns and 40 - 50 microns respectively; in the third rolling pass process, the thicknesses of the aluminum foil at the inlet and outlet are 40 - 50 microns and 15 - 25 microns respectively; in the fourth rolling pass process, the thicknesses of the aluminum foil at the inlet and outlet are 15 - 25 microns and 10 - 15 microns respectively.
7. A preparation process for battery aluminum foil according to claim 6, characterized in that, The reduction ratio of the first rolling pass is 52.27%, the reduction ratio of the second rolling pass is 56.19%, the reduction ratio of the third rolling pass is 53.26%, and the reduction ratio of the fourth rolling pass is 39.53%.
8. A process for preparing battery aluminum foil according to claim 1, characterized in that, The viscosity of the rolling oil is 1.80 - 2.30 mm² / s.
9. A preparation process of battery aluminum foil according to claim 8, characterized in that, The rolling oil used is No. 90 oil.
10. A preparation process of battery aluminum foil according to claim 8, characterized in that, The flattening rolls in the first rolling pass, the second rolling pass, and the third rolling pass use flattening rolls with a camber of 20‰ mm.