Device for improving the thinning and extension of the blanking space of the pole piece and a method for calculating the diameter of the roller
By optimizing the rolling process and designing extension rollers with specific diameters, the problem of insufficient extension in the thinning and blanking areas of lithium-ion battery electrodes was solved, thereby improving the preparation accuracy of the electrodes and the performance of the batteries.
Patent Information
- Application Number
- CN202610807883.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-05
- Publication Date
- 2026-07-31
AI Technical Summary
In existing technologies, the thinning and blanking areas of lithium-ion battery electrodes are not sufficiently extended during the manufacturing process, leading to electrode warping, wrinkling, and cracking, which affects battery performance.
Design a device to improve electrode thinning and blanking extension. By optimizing the rolling process, use extension rollers made of stainless steel or aluminum alloy, with roller diameter designed as needed, to ensure that the extension rate of the thinned area and the blanking area is consistent, avoiding warping and wrinkles.
It improves the preparation precision and yield of electrode sheets, enhances the overall performance of the battery, and solves the problem of insufficient extension in the thinned and blank areas.
Smart Images
Figure CN122480089A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of lithium-ion battery electrode preparation technology, and more specifically, it relates to an apparatus for improving electrode thinning and blanking extension. This invention also relates to a method for calculating the roller diameter d2 at the junction of the thinning area and the blanking area of the apparatus for improving electrode thinning and blanking extension, and a method for calculating the roller diameter d1 of the blanking area of the apparatus for improving electrode thinning and blanking extension. Background Technology
[0002] As a core component of lithium-ion batteries, the quality of electrode fabrication directly determines battery performance. During electrode fabrication, in addition to the normal area, thinning areas are also included. The longitudinal extension of the thinned and blank areas is less than that of the normal area. Currently, most manufacturers address this by attaching Teflon tape to the stretching roller to control the stretching. This method is difficult to operate, suffers from poor alignment between the Teflon tape and the material area, and the stretching effect is related to the tape thickness, making it difficult to control. This leads to warping, wrinkling, and cracking of the electrode, affecting subsequent processes. Therefore, developing an electrode fabrication method and apparatus that can improve the stretching performance of the thinned and blank areas, while being simple, cost-effective, and suitable for large-scale production, has become a pressing technical problem in the field of lithium-ion battery electrode fabrication. This is the objective of this invention.
[0003] The existing technology includes a technology entitled "A Flattening Device for Coated Electrodes of Lithium-ion Batteries" with publication (announcement) number "223385592U". This technology proposes a flattening device for coated electrodes of lithium-ion batteries, which adopts a raised structure. An annular protrusion is set in the middle of the stretching roller corresponding to the coating blank area. The annular protrusion has threaded protrusions symmetrically distributed on the left and right sides. In use, the position of the annular protrusion of the stretching roller is aligned with the coating blank area, which can effectively expand and shape the wrinkled foil in the middle blank area after exiting the oven, stretching the blank area into an arc shape and avoiding the appearance of wrinkles in the blank area.
[0004] However, this technology does not address the technical issues and solutions of this application. Summary of the Invention
[0005] The technical problem to be solved by the present invention is to provide a device with a simple structure and reliable control to improve the thinning and blanking extension of electrode sheets, which addresses the shortcomings of the existing technology. By optimizing the rolling process, the device solves the problems of insufficient extension of the thinning and blanking areas and electrode warping in the existing electrode sheets, thereby improving the electrode sheet preparation accuracy and yield, and thus improving the overall performance of the battery.
[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: This invention relates to an apparatus for improving electrode thinning and blanking extension. The extension roller includes a normal zone, a thinning zone, and a blanking zone. The roller diameter d1 of the blanking zone is greater than the roller diameter d2 at the junction of the blanking zone and the thinning zone. The roller diameter d3 at the junction of the thinning zone and the normal zone is equal to the roller diameter d4 of the normal zone. The diameter gradually decreases from roller diameter d2 to roller diameter d3. The electrode includes a coating in the normal zone and a coating in the thinning zone. The width W1 of the normal zone is equal to the width W2 of the coating in the normal zone. The width W3 of the thinning zone is equal to the width W4 of the coating in the thinning zone. The width W5 of the blanking zone is greater than the width W6 of the uncoated area on one side of the foil.
[0007] The foil has a coating on its upper and lower surfaces, and the coating on the upper and lower surfaces includes a normal area coating and a thinned area coating, respectively.
[0008] The normal zone coating includes a1 and b1, which are pre-rolling marking points of the normal zone coating. The distance between a1 and b1 is the marking distance L1 of the normal zone coating before the electrode roll. The edge of the thinned zone coating 7 (at the junction with the blank area) includes a2 and b2, which are pre-rolling marking points of the thinned zone coating. The distance between a2 and b2 is the marking distance L2 of the thinned zone coating before the electrode roll.
[0009] The normal zone coating includes marking point a3 and marking point b3 after normal zone coating roll pressing, and the distance between marking point a3 and marking point b3 after normal zone coating roll pressing is the marking distance L3 of the normal zone coating after electrode roll pressing; the thinned zone coating includes marking point a4 and marking point b4 after thinned zone coating roll pressing, and the distance between marking point a4 and marking point b4 after thinned zone coating roll pressing is the marking distance L4 of the thinned zone coating after electrode roll pressing.
[0010] When calculating the diameter d2 at the junction of the thinned area and the blank area: The elongation of the coating in the normal zone = (distance L3 of the coating mark in the normal zone after electrode rolling / distance L1-1 of the coating mark in the normal zone before electrode rolling) * 100%; The elongation of the coating in the thinned area = (distance L4 of the coating mark in the thinned area after electrode rolling / distance L2-1 of the coating mark in the thinned area before electrode rolling) * 100%; The roller diameter at the junction of the thinning zone and the blanking zone = (100% + elongation of the coating in the normal zone - elongation of the coating in the thinning zone) * (roller diameter d4 in the normal zone + double-sided coating thickness in the normal zone after roll pressing - double-sided coating thickness in the thinning zone after roll pressing).
[0011] When calculating the roller diameter d1 of the blank area: The elongation of the coating in the normal zone = (distance L3 of the coating mark in the normal zone after electrode rolling / distance L1-1 of the coating mark in the normal zone before electrode rolling) * 100%; The roller diameter d1 in the blank area = (roller diameter d4 in the normal area + coating thickness on one side of the normal area after electrode rolling * 2) * (100% + elongation of the coating in the normal area).
[0012] The normal zone, thinning zone, and blanking zone of the stretching roller are an integrated structure, and the material of the stretching roller 4 is stainless steel or aluminum alloy.
[0013] The stretching roller is threaded onto a roller shaft and is rotatable relative to the roller shaft, which is fixed to the roller press. The roller press also includes an upper main roller and a lower main roller, with the stretching roller located behind both the upper and lower main rollers.
[0014] This invention also relates to a method for calculating the diameter d2 at the junction of the thinned area and the blanking area of an apparatus for improving electrode thinning and blanking extension, the specific steps of which are as follows: S1. Measure and obtain the distance L1 of the coating mark in the normal area before the electrode roll is pressed; Measure the distance L2 of the coating mark in the thinned area of the electrode sheet before rolling; S2. Roll-press the electrode sheet to the standard required thickness value; S3. Measure and obtain the coating mark distance L3 in the normal area after the electrode is rolled; The distance L4 of the coating mark in the thinned area after the electrode sheet is rolled is measured. S4. Elongation of coating in normal zone = (Distance of coating mark in normal zone after electrode roll pressing L3 / Distance of coating mark in normal zone before electrode roll pressing L1-1) * 100%; S5. Elongation of the coating in the thinned area = (Distance of the coating mark in the thinned area after electrode rolling L4 / Distance of the coating mark in the thinned area before electrode rolling L2-1) * 100%; S6. Roll diameter at the junction of the thinning zone and the blanking zone = (100% + elongation of the coating in the normal zone - elongation of the coating in the thinning zone) * (roll diameter d4 of the normal zone + thickness of the double-sided coating in the normal zone after roll pressing - thickness of the double-sided coating in the thinning zone after roll pressing).
[0015] This invention also relates to a method for calculating the roller diameter d1 of the blanking zone in an improved electrode thinning and blanking extension device, the specific steps of which are as follows: S1. Measure and obtain the distance L1 of the coating mark in the normal area before the electrode roll is pressed; S2. Roll-press the electrode sheet to the standard required thickness value; S3. Measure and obtain the coating mark distance L3 in the normal area after the electrode is rolled; The elongation of the coating in the normal zone = (distance L3 of the coating mark in the normal zone after electrode rolling / distance L1-1 of the coating mark in the normal zone before electrode rolling) * 100%; S4. Roller diameter d1 in the blank area = (roller diameter d4 in the normal area + coating thickness on one side of the normal area after electrode rolling * 2) * (100% + elongation of coating in the normal area).
[0016] The working principle and beneficial effects of the technical solution adopted in this invention are as follows: The device for improving electrode thinning and blanking extension described in this invention effectively enhances the electrode manufacturing process by optimizing the rolling process. The rolling process improves the extension capacity of the thinning and blanking areas of the electrode by improving the structure of the extension roller, so that the extension of the normal area, thinning area and blanking area of the electrode is consistent. This improves the wrinkles and strip breakage problems caused by the small extension of the blanking area and the electrode warping problem caused by the small extension of the thinning area during the rolling process, and effectively improves the product quality. Attached Figure Description
[0017] The following is a brief explanation of the contents depicted in the accompanying drawings and the markings therein: Figure 1 This is a cross-sectional structural schematic diagram of the stretching roller described in this invention; Figure 2 This is a cross-sectional structural diagram of the coating and foil material described in this invention; Figure 3 This is a cross-sectional view of the stretching roller described in this invention during operation. Figure 4 These are schematic diagrams showing the different widths of the stretching roller described in this invention; Figure 5 These are schematic diagrams showing the different widths of the coating and foil materials described in this invention; Figure 6 This is a schematic diagram of the coating marking distance L1 in the normal area before electrode rolling and the coating marking distance L3 in the normal area after electrode rolling, as described in this invention. Figure 7 This is a schematic diagram of the coating marking distance L2 in the thinned area before electrode rolling and the coating marking distance L4 in the thinned area after electrode rolling, as described in this invention. The labels in the attached diagram are as follows: 1. Normal zone; 2. Thinning zone; 3. Blank zone; 4. Extending roller; 5. Foil; 6. Normal zone coating; 7. Thinning zone coating; 8. Roller shaft; 9. Upper main roller of the roller press; 10. Lower main roller of the roller press. Detailed Implementation
[0018] The following description, with reference to the accompanying drawings, provides a more detailed explanation of the specific embodiments of the present invention, including the shape and structure of each component, the relative positions and connections between the parts, the functions and working principles of each part: As attached Figure 1 - Appendix Figure 7 As shown, this invention provides an apparatus for improving electrode thinning and blanking extension. The extending roller 4 includes a normal zone 1, a thinning zone 2, and a blanking zone 3. The roller diameter d1 of the blanking zone 3 is greater than the roller diameter d2 at the junction of the blanking zone 3 and the thinning zone 2. The roller diameter d3 at the junction of the thinning zone 2 and the normal zone 1 is equal to the roller diameter d4 of the normal zone 1. The diameter gradually decreases from roller diameter d2 to roller diameter d3. The electrode includes a normal zone coating 6 and a thinning zone coating 7. The width W1 of the normal zone 1 is equal to the width W2 of the normal zone coating 6. The width W3 of the thinning zone 2 is equal to the width W4 of the thinning zone coating 7. The width W5 of the blanking zone 3 is greater than the width W6 of the uncoated area on one side of the foil 5. This structure addresses the shortcomings of the prior art and proposes an improved technical solution. The principle and effect of the above improvement are as follows: Because the coating in the normal area 1 of the electrode sheet is thick, after the electrode sheet is rolled, the elongation rate of the normal area 1 is greater than that of the thinned area 2 and the blank area 3. This results in the normal area 1 being longer than the thinned area 2 and the blank area 3, leading to different elongation rates and causing phenomena such as warping, wrinkling, and cracking of the electrode sheet, affecting subsequent processes. Through the structural improvement of this invention, a special roller structure is formed. When the electrode sheet passes through this structured roller, the elongation rate of the thinned area and the blank area of the electrode sheet is greater than that of the normal area, ultimately making the elongation of the normal area, the thinned area, and the blank area of the electrode sheet consistent. Therefore, the overall performance of the electrode sheet can be effectively improved. Therefore, when the structure of this invention is used for electrode sheet preparation, the structural improvement can effectively improve the insufficient elongation of the thinned area and the blank area of the electrode sheet during the rolling process, making the elongation rate of the normal area, the thinned area, and the blank area of the electrode sheet consistent, avoiding electrode sheet cracking, strip breakage, and warping caused by insufficient elongation during rolling. The device and method described in this application can improve the process capability of battery cells.
[0019] The foil 5 has a coating on its upper and lower surfaces, and the coating on the upper and lower surfaces includes a normal area coating 6 and a thinned area coating 7, respectively.
[0020] The apparatus described in this invention includes an upper main roller 9 and a lower main roller 10 of a roller press, which are used to roll the electrode sheet. That is, the electrode sheet before rolling passes through the upper main roller 9 and the lower main roller 10 to become a rolled electrode sheet. An extension roller 4 is located behind the upper main roller 9 and the lower main roller 10. After rolling, the electrode sheet passes through the extension roller 4, which plays a crucial role in solving the problem of this invention.
[0021] The normal zone coating 6 includes a mark point a1 and a mark point b1 before normal zone coating roll pressing. The distance between the mark point a1 and the mark point b1 before normal zone coating roll pressing is the normal zone coating mark distance L1 before electrode roll pressing. The thinned zone coating 7 includes a mark point a2 and a mark point b2 before thinned zone coating roll pressing. The distance between the mark point a2 and the mark point b2 before thinned zone coating roll pressing is the thinned zone coating mark distance L2 before electrode roll pressing.
[0022] The normal zone coating 6 includes a mark point a3 and a mark point b3 after normal zone coating roll pressing, and the distance between the mark points a3 and b3 after normal zone coating roll pressing is the normal zone coating mark distance L3 after electrode roll pressing; the thinned zone coating 7 includes a mark point a4 and a mark point b4 after thinned zone roll pressing, and the distance between the mark points a4 and b4 after thinned zone roll pressing is the thinned zone coating mark distance L4 after electrode roll pressing.
[0023] When calculating the diameter d2 at the junction of the thinned area 2 and the blank area 3: The elongation of coating 6 in the normal zone = (distance L3 of coating mark in the normal zone after electrode rolling / distance L1-1 of coating mark in the normal zone before electrode rolling) * 100%; The elongation of the thinned coating 7 = (distance L4 of the thinned coating mark after electrode rolling / distance L2-1 of the thinned coating mark before electrode rolling) * 100%; The roller diameter at the junction of the thinning zone 2 and the blanking zone 3 = (100% + elongation of the coating 6 in the normal zone - elongation of the coating 7 in the thinning zone) * (roller diameter d4 of the normal zone 1 + double-sided coating thickness of the normal zone 6 after roller pressing - double-sided coating thickness of the thinning zone 7 after roller pressing).
[0024] In the device of the present invention, the function and effect of calculating the diameter d2 at the junction of the thinned area 2 and the blank area 3 is as follows: the diameter d2 corresponds to the edge of the electrode thinning area, where the coating is the least and the point with the lowest elongation of the thinned area is located. That is, d2 is the point with the largest diameter of the corresponding electrode thinning area. The diameter gradually decreases from d2 to d3, with the aim of making the elongation of the electrode thinning area consistent with that of the normal area.
[0025] When calculating the roller diameter d1 of the blank area 3: The elongation of coating 6 in the normal zone = (distance L3 of coating mark in the normal zone after electrode rolling / distance L1-1 of coating mark in the normal zone before electrode rolling) * 100%; The roller diameter d1 of the blank area 3 is equal to (the roller diameter d4 of the normal area 1 + the single-sided thickness of the coating in the normal area after the electrode is rolled * 2) * (100% + the elongation of the coating in the normal area 6).
[0026] In the device of the present invention, the function and effect of calculating the roller diameter d1 of the blank area 3 is as follows: this part of the roller corresponds to the blank area of the electrode sheet. After the blank area of the electrode sheet is pressed by the roller, there is no extension. The increase of the roller diameter is also to make the blank area of the electrode sheet stretch after passing through the roller, which is consistent with the elongation rate of the thinning area and the normal area.
[0027] The normal zone 1, thinning zone 2, and blanking zone 3 of the stretching roller 4 are an integral structure, and the material of the stretching roller 4 is stainless steel or aluminum alloy.
[0028] The stretching roller 4 is threaded onto the roller shaft 8, and the stretching roller 4 can rotate relative to the roller shaft 8, which is fixed to the roller press.
[0029] This invention also relates to a method for calculating the diameter d2 at the junction of the thinning region 2 and the blanking region 3 in an apparatus for improving electrode thinning and blanking extension, the specific steps of which are as follows: S1. Measure and obtain the distance L1 of the coating mark in the normal area before the electrode roll is pressed; Measure the distance L2 of the coating mark in the thinned area of the electrode sheet before rolling; S2. Roll-press the electrode sheet to the standard required thickness value; S3. Measure and obtain the coating mark distance L3 in the normal area after the electrode is rolled; The distance L4 of the coating mark in the thinned area after the electrode sheet is rolled is measured. S4. Elongation of coating 6 in normal zone = (Distance L3 of coating mark in normal zone after electrode rolling / Distance L1-1 of coating mark in normal zone before electrode rolling) * 100%; S5. Elongation of the coating in the thinned area 7 = (Distance of the coating mark in the thinned area after electrode rolling L4 / Distance of the coating mark in the thinned area before electrode rolling L2-1) * 100%; S6. Roll diameter at the junction of thinning zone 2 and blanking zone 3 = (100% + elongation of coating 6 in normal zone - elongation of coating 7 in thinning zone) * (roller diameter d4 of normal zone 1 + double-sided coating thickness of normal zone 6 after roll pressing - double-sided coating thickness of thinning zone 7 after roll pressing).
[0030] This invention also relates to a method for calculating the roller diameter d1 of the blanking zone 3 in an improved electrode thinning and blanking extension device, the specific steps of which are as follows: S1. Measure and obtain the distance L1 of the coating mark in the normal area before the electrode roll is pressed; S2. Roll-press the electrode sheet to the standard required thickness value; S3. Measure and obtain the coating mark distance L3 in the normal area after the electrode is rolled; The elongation of coating 6 in the normal zone = (distance L3 of coating mark in the normal zone after electrode rolling / distance L1-1 of coating mark in the normal zone before electrode rolling) * 100%; S4. Roller diameter d1 of blank area 3 = (roller diameter d4 of normal area 1 + single-sided thickness of coating in normal area after electrode rolling * 2) * (100% + elongation of coating 6 in normal area).
[0031] The electrode used in the rolling process can be a lithium manganese oxide system, a lithium iron phosphate system, a ternary system, or other system positive electrode, or a graphite system or other system negative electrode. As a preferred embodiment, the electrode used in this embodiment is a lithium iron phosphate system positive electrode.
[0032] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any improvements made by adopting the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.
Claims
1. An apparatus for improving electrode thinning and blanking extension, characterized in that: The stretching roller (4) includes a normal area (1), a thinning area (2), and a blank area (3). The roller diameter d1 of the blank area (3) is greater than the roller diameter d2 at the junction of the blank area (3) and the thinning area (2). The roller diameter d3 at the junction of the thinning area (2) and the normal area (1) is equal to the roller diameter d4 of the normal area (1). The diameter gradually decreases from roller diameter d2 to roller diameter d3. The electrode sheet includes a normal area coating (6) and a thinning area coating (7). The width W1 of the normal area (1) is equal to the width W2 of the normal area coating (6). The width W3 of the thinning area (2) is equal to the width W4 of the thinning area coating (7). The width W5 of the blank area (3) is greater than the width W6 of the uncoated area on one side of the foil (5).
2. The apparatus for improving electrode thinning and blanking extension according to claim 1, characterized in that: The foil (5) has coatings on its upper and lower surfaces, and the coatings on the upper and lower surfaces include a normal zone coating (6) and a thinned zone coating (7), respectively.
3. The apparatus for improving electrode thinning and blanking extension according to claim 1 or 2, characterized in that: The normal zone coating (6) includes a mark point a1 and a mark point b1 before normal zone coating roll pressing. The distance between the mark point a1 and the mark point b1 before normal zone coating roll pressing is the normal zone coating mark distance L1 before electrode roll pressing. The thinning zone coating (7) includes a mark point a2 and a mark point b2 before thinning zone coating roll pressing. The distance between the mark point a2 and the mark point b2 before thinning zone coating roll pressing is the thinning zone coating mark distance L2 before electrode roll pressing.
4. The apparatus for improving electrode thinning and blanking extension according to claim 3, characterized in that: The normal zone coating (6) includes a mark point a3 and a mark point b3 after rolling of the normal zone coating. The distance between the mark point a3 and the mark point b3 after rolling of the normal zone coating is the mark distance L3 of the normal zone coating after rolling of the electrode sheet. The coating in the thinning zone (7) includes the marking point a4 and the marking point b4 after the thinning zone is rolled. The distance between the marking point a4 and the marking point b4 after the thinning zone is the marking distance L4 of the coating in the thinning zone after the electrode roll is rolled.
5. The apparatus for improving electrode thinning and blanking extension according to claim 4, characterized in that: When calculating the diameter d2 at the junction of the thinned area (2) and the blank area (3): The elongation of the coating in the normal zone (6) = (distance L3 of the coating mark in the normal zone after electrode rolling / distance L1-1 of the coating mark in the normal zone before electrode rolling) * 100%; The elongation of the coating in the thinned area (7) = (distance L4 of the coating mark in the thinned area after electrode rolling / distance L2-1 of the coating mark in the thinned area before electrode rolling) * 100%; The roller diameter at the junction of the thinning zone (2) and the blanking zone (3) = (100% + elongation of the coating (6) in the normal zone - elongation of the coating (7) in the thinning zone) * (roller diameter d4 of the normal zone (1) + double-sided coating thickness of the normal zone (6) after roller pressing - double-sided coating thickness of the thinning zone (7) after roller pressing).
6. The apparatus for improving electrode thinning and blanking extension according to claim 4, characterized in that: When calculating the roller diameter d1 of the blank area (3): The elongation of coating 6 in the normal zone = (distance L3 of coating mark in the normal zone after electrode rolling / distance L1-1 of coating mark in the normal zone before electrode rolling) * 100%; The roller diameter d1 of the blank area 3 is equal to (the roller diameter d4 of the normal area (1) + the single-sided thickness of the coating in the normal area after the electrode is rolled * 2) * (100% + the elongation of the coating in the normal area (6)).
7. The apparatus for improving electrode thinning and blanking extension according to claim 1, characterized in that: The normal area (1), thinning area (2), and blanking area (3) of the stretching roller (4) are an integral structure, and the material of the stretching roller (4) is stainless steel or aluminum alloy.
8. The apparatus for improving electrode thinning and blanking extension according to claim 1 or 2, characterized in that: The extension roller (4) is threaded on the roller shaft (8) and can rotate relative to the roller shaft (8). The roller shaft (8) is fixed to the roller press. It also includes an upper main roller (9) and a lower main roller (10) of the roller press. The extension roller (4) is located behind the upper main roller (9) and the lower main roller (10) of the roller press.
9. A method for calculating the roller diameter d2 at the junction of the thinning zone (2) and the blanking zone (3) of the apparatus for improving electrode thinning and blanking extension according to any one of claims 1 to 8, characterized in that: S1. Measure and obtain the distance L1 of the coating mark in the normal area before the electrode roll is pressed; Measure the distance L2 of the coating mark in the thinned area of the electrode sheet before rolling; S2. Roll-press the electrode sheet to the standard required thickness value; S3. Measure and obtain the coating mark distance L3 in the normal area after the electrode is rolled; The distance L4 of the coating mark in the thinned area after the electrode sheet is rolled is measured. S4. Elongation of the coating in the normal zone (6) = (Distance L3 of the coating mark in the normal zone after electrode rolling / Distance L1-1 of the coating mark in the normal zone before electrode rolling) * 100%; S5. Elongation of the coating in the thinned area (7) = (distance L4 of the coating mark in the thinned area after electrode rolling / distance L2-1 of the coating mark in the thinned area before electrode rolling) * 100%; S6. Roll diameter at the junction of the thinning zone (2) and the blanking zone (3) = (100% + elongation of the coating (6) in the normal zone - elongation of the coating (7) in the thinning zone) * (roller diameter d4 of the normal zone (1) + double-sided coating thickness of the normal zone (6) after rolling - double-sided coating thickness of the thinning zone (7) after rolling).
10. The method for calculating the roller diameter d1 of the blanking area (3) of the improved electrode thinning and blanking extension device according to any one of claims 1 to 8, characterized in that: S1. Measure and obtain the distance L1 of the coating mark in the normal area before the electrode roll is pressed; S2. Roll-press the electrode sheet to the standard required thickness value; S3. Measure and obtain the coating mark distance L3 in the normal area after the electrode is rolled; The elongation of the coating in the normal zone (6) = (distance L3 of the coating mark in the normal zone after electrode rolling / distance L1-1 of the coating mark in the normal zone before electrode rolling) * 100%; S4. Roller diameter d1 of blank area (3) = (roller diameter d4 of normal area (1) + single-sided thickness of coating in normal area after electrode rolling * 2) * (100% + elongation of coating in normal area (6)).