A pole piece, a processing device for the pole piece, and a method for manufacturing a pole piece

Abstract

The application belongs to the technical field of batteries, and particularly relates to a pole piece, which comprises a foil material, at least one surface of the foil material in the thickness direction is provided with a coating area and a plurality of second empty foil areas, two adjacent second empty foil areas have a gap therebetween, the plurality of gaps are arranged at intervals along the length direction of the foil material, the coating area comprises a normal material area and a plurality of second thinning areas which are connected to each other, the plurality of second thinning areas are arranged at intervals along the edge of the length direction of the foil material, and at least part of the normal material area is arranged between two adjacent second thinning areas. The application greatly reduces the area of the thinning area, makes the height consistency of the battery better and the hot-pressing effect better, and ensures that the cycle performance of the battery is optimized. In addition, the application further provides a processing device for the pole piece and a preparation method of the pole piece.

Description

Technical Field

[0001] This invention belongs to the technical field of batteries, specifically relating to an electrode, a processing apparatus for the electrode, and a method for preparing the electrode. Background Technology

[0002] Lithium-ion batteries possess advantages such as light weight, high capacity, long lifespan, low self-discharge rate, no memory effect, and no pollution. As the requirements for cell mass and volumetric energy density increase, the number of electrode layers is also gradually increasing, from a few or a dozen layers to dozens or even hundreds of layers. Simultaneously, due to the thinning effect of non-tab regions within the electrode sheets, the thickness difference between the edge and center regions of a single cell's tabs gradually increases, from tens of μm to hundreds of μm. This has a cumulative impact on the later hot-pressing of the cell. Furthermore, the difference in compaction density and thickness between the thinned non-tab regions and the normal material regions can cause edge bulging and lithium plating abnormalities in the later stages of cell cycling. Therefore, a novel technical solution is urgently needed to address these problems. Summary of the Invention

[0003] One of the objectives of this invention is to provide an electrode sheet that significantly reduces the area of ​​the thinned region, thereby avoiding abnormal conditions such as edge bulging and lithium plating in the later stages of cell cycling, and reducing slurry waste.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] An electrode includes a foil, at least one surface of the foil in the thickness direction having a coating area and a plurality of second empty foil areas, with a gap between adjacent two second empty foil areas, the plurality of gaps being spaced apart along the length direction of the foil, the coating area including interconnected normal material areas and a plurality of second thinning areas, the plurality of second thinning areas being spaced apart along the edges of the foil in the length direction, at least a portion of the normal material area being disposed between adjacent two second thinning areas.

[0006] Preferably, the normal material area has a first edge and a second edge arranged alternately along the length direction of the foil, the first edge and the second edge having a spacing along the width direction of the foil, the second thinning area being located between the first edge and the second empty foil area, the first edge being located at the end of the second thinning area away from the second empty foil area, and the second edge being flush with the end of the second thinning area near the second empty foil area.

[0007] Preferably, both the first edge and the second edge extend along the length direction of the foil, and the first edge and the second edge are parallel to each other along the width direction of the foil. The vertical distance between the first edge and the second edge along the width direction of the foil is equal to the dimension of the second thinning area along the width direction of the foil. That is, the first edge is located at the end of the second thinning area away from the second empty foil area, and the second edge is level with the end of the second thinning area near the second empty foil area.

[0008] Preferably, two adjacent second empty foil areas and the second edge form the notch, and the second empty foil areas are exposed outside the coating area.

[0009] Preferably, along the thickness direction of the foil, the thickness of the second thinning zone is less than the thickness of the normal material zone.

[0010] Preferably, along the width direction of the foil, the second thinning area corresponds one-to-one with the second empty foil area.

[0011] A second objective of this invention is to provide an apparatus for processing electrode sheets, comprising:

[0012] A slurry dispensing assembly has a gasket, the gasket including a discharge port and two oppositely arranged guide ends, the discharge port being located between the two guide ends, the discharge port being used to deliver slurry to the surface of the foil;

[0013] A control thinning component is located on one side of the discharge port. The control thinning component is slidably connected to the slurry discharge component so that the control thinning component moves back and forth at the discharge port along the width direction of the foil at a preset amplitude.

[0014] Preferably, the slurry discharge assembly further includes an upper pressure plate and a lower pressure plate, the gasket is disposed between the upper pressure plate and the lower pressure plate, the lower surface of the upper pressure plate, the upper surface of the lower pressure plate and the two guide ends together define the discharge port, the lower pressure plate has a flow groove on the surface facing the gasket, and the opposite ends of the flow groove have inlets.

[0015] Preferably, the control thinning component includes a stop block and a driver, the upper pressure plate and the lower pressure plate have mounting surfaces on the side corresponding to the discharge port, the mounting surfaces are provided with slide rails, the stop block is slidably connected to the slide rails, and the stop block is connected to the output end of the driver.

[0016] The third objective of this invention is to provide a method for preparing an electrode sheet, comprising the following steps:

[0017] S1. The slurry is conveyed to the surface of the foil along the coating direction, so that the slurry flows from the outlet to the surface of the foil and forms the required normal material area, first thinning area and second thinning area on the surface of the foil. The surface of the foil has a first empty foil area and a second empty foil area without slurry coating. The first thinning area and the second thinning area are distributed on opposite sides of the edge of the normal material area along the width direction of the foil, so that the first empty foil area corresponds to the first thinning area and the second empty foil area corresponds to the second thinning area.

[0018] S2. Remove the first thinning zone and the first empty foil zone to obtain the desired electrode sheet.

[0019] Preferably, step S1 further includes: moving the stop block back and forth at the outlet along the width direction of the foil at a preset amplitude, and forming a first thinning zone and a second thinning zone alternately according to the movement path of the stop block at the outlet.

[0020] Preferably, step S1 further includes: controlling the position and width of the first thinning area coated on the foil to be cut, so that the position to be cut has a corresponding first thinning area and a first empty foil area.

[0021] Preferably, step S1 further includes: controlling the width of the second thinning zone so that a second empty foil zone is formed between the second thinning zone and the edge of the foil.

[0022] Preferably, step S2 further includes: removing the first thinned area and the first empty foil area by laser cutting.

[0023] The beneficial effects of this invention are as follows:

[0024] 1) The electrode sheet of the present invention includes a foil, at least one surface of the foil in the thickness direction is provided with a coating area and a plurality of second empty foil areas, there is a gap between two adjacent second empty foil areas, the plurality of gaps are spaced apart along the length direction of the foil, the coating area includes a normal material area and a plurality of second thinning areas connected to each other, the plurality of second thinning areas are spaced apart along the edge of the foil in the length direction, at least part of the normal material area is provided between two adjacent second thinning areas, wherein the range of the thinning area of ​​the electrode sheet can be controlled directly below the tab, which greatly reduces the area of ​​the thinning area, making the cell height consistency and hot pressing effect better, and ensuring that the cycle performance of the cell is optimized;

[0025] 2) The electrode processing apparatus of the present invention includes a slurry dispensing assembly and a control thinning assembly. The slurry dispensing assembly has a gasket, which includes a discharge port and two oppositely arranged guide ends. The discharge port is located between the two guide ends and is used to deliver slurry to the surface of the foil. The control thinning assembly is located on one side of the discharge port and is slidably connected to the slurry dispensing assembly. By allowing the slurry to flow from the discharge port of the gasket to the surface of the foil, a normal material area is formed on the surface of the foil. Furthermore, the control thinning assembly moves back and forth at the discharge port along the width direction of the foil at a preset amplitude. The control thinning assembly enables the slurry to form the required first thinning area and second thinning area on the surface of the foil. The surface of the foil also has a first empty foil area and a second empty foil area without slurry coating. By controlling the foil surface to form a corresponding coating and molding structure in this targeted manner, it is beneficial to remove the thinning area of ​​the non-tab area in the subsequent process, thereby effectively optimizing the structure of the electrode and improving the quality of the electrode and the battery cell.

[0026] 3) The electrode preparation method of the present invention includes forming a required normal material area, a first thinning area and a second thinning area on the surface of a foil. The surface of the foil has a first empty foil area and a second empty foil area without coating paste. The first thinning area and the second thinning area are distributed on opposite sides of the edge of the normal material area along the width direction of the foil. The first thinning area and the first empty foil area are removed to obtain the required electrode. That is, the foil surface is targeted to form a corresponding coating and molding structure, and the thinning area in the non-tab area is removed. This effectively reduces the area of ​​the thinning area, ensures that the cycle performance of the cell is optimized, and also effectively avoids the occurrence of cell bulging and lithium plating. Attached Figure Description

[0027] The features, advantages, and technical effects of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings.

[0028] Figure 1 This is one of the structural schematic diagrams of the electrode sheet of the present invention.

[0029] Figure 2 This is a cross-sectional view of the electrode sheet of the present invention.

[0030] Figure 3 This is a schematic diagram of the structure of the gasket, stop block, upper pressure plate, lower pressure plate and slide rail of the present invention.

[0031] Figure 4 This is a flowchart of the electrode preparation method of the present invention.

[0032] Figure 5 This is a schematic diagram of the structure of the foil material having a first thinning zone and a second thinning zone according to the present invention.

[0033] Figure 6 This is the second schematic diagram of the electrode structure of the present invention.

[0034] Figure 7 This is a schematic diagram illustrating the operation of conveying slurry to a three-dimensional foil material according to an embodiment of the present invention.

[0035] Figure 8 This is a schematic diagram showing the moving direction of the stop block according to Embodiment 3 of the present invention.

[0036] Figure 9 This is a schematic diagram of the structure of the gasket and the pressure plate of the present invention.

[0037] The reference numerals in the attached figures are explained as follows:

[0038] 1. Foil material; 11. First thinning zone; 12. Second thinning zone; 13. First empty foil zone; 14. Second empty foil zone; 15. Notch; 101. First edge; 102. Second edge;

[0039] 2. Gasket; 20. Guide end;

[0040] 3. Stop block; 4. Upper pressure plate; 5. Lower pressure plate; 50. Flow groove; 6. Slide rail;

[0041] X, width direction of the foil; Y, length direction of the foil; Z, thickness direction of the foil; T1, first direction; T2, second direction. Detailed Implementation

[0042] The specification and claims use certain terms to refer to specific components. Those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The term "comprising" throughout the specification and claims is an open-ended term and should be interpreted as "comprising but not limited to." "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error. Furthermore, terms such as "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0043] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0044] The inventors discovered that in existing electrodes, due to the presence of thinned areas in the non-tab region, the compaction density and thickness of these thinned areas differ significantly from the normal material area. This can easily lead to edge bulging and lithium plating abnormalities in the later stages of cell cycling. Furthermore, the inventors also found that the slurry coating process during electrode preparation significantly impacts electrode quality. Factors such as the coating height at the tab root and the assembly ratio during packaging also affect electrode quality. Using wider foil and more slurry to prepare the electrode results in substantial slurry waste. Therefore, the inventors painstakingly identified the structural defects and excessive slurry waste in the electrode. To improve the quality of both the electrode and the cell, this invention proposes a novel electrode, a processing apparatus for the electrode, and a method for preparing the electrode to effectively optimize the electrode structure and solve the aforementioned technical problems.

[0045] The following is in conjunction with the appendix Figures 1-9 The present invention will be described in further detail, but this is not intended to limit the invention.

[0046] Implementation Method 1

[0047] A type of electrode, see Figure 1 and Figure 2 The foil 1 includes a coating area and a plurality of second empty foil areas 14 on at least one surface of the foil 1 in the thickness direction Z. There is a gap 15 between two adjacent second empty foil areas 14. The plurality of gaps 15 are arranged at intervals along the length direction Y of the foil 1. The coating area includes a normal material area 10 and a plurality of second thinning areas 12 connected to each other. The plurality of second thinning areas 12 are arranged at intervals along the edge of the length direction Y of the foil 1. At least a portion of the normal material area 10 is disposed between two adjacent second thinning areas 12.

[0048] Among them, the second empty foil area 14 is the electrode tab of the electrode sheet, and each electrode tab exposed in the coating area is a part of the foil material 1.

[0049] Preferably, the normal material area 10 has a first edge 101 and a second edge 102 arranged alternately along the length direction Y of the foil 1, the first edge 101 and the second edge 102 having a spacing along the width direction X of the foil 1, and the second thinning area 12 is located between the first edge 101 and the second empty foil area 14.

[0050] Preferably, the first edge 101 and the second edge 102 both extend along the length direction Y of the foil 1, and the first edge 101 and the second edge 102 are parallel to each other along the width direction X of the foil 1. The vertical distance between the first edge 101 and the second edge 102 along the width direction X of the foil 1 is equal to the size of the second thinning area 12 along the width direction X of the foil 1, so that the first edge 101 is located at the end of the second thinning area 12 away from the second empty foil area 14, and the second edge 102 is flush with the end of the second thinning area 12 near the second empty foil area 14.

[0051] Preferably, two adjacent second empty foil regions 14 and the second edge 102 form a notch 15, which facilitates the penetration of electrolyte.

[0052] Preferably, along the thickness direction Z of the foil 1, the thickness of the second thinning zone 12 is less than the thickness of the normal material zone 10, so as to be more conducive to the stacking and assembly of multiple electrode sheets and to ensure the normal use of the battery cell.

[0053] Preferably, along the width direction X of the foil 1, the second thinning area 12 corresponds one-to-one with the second empty foil area 14, and the plurality of second thinning areas 12 are arranged at equal intervals along the edge of the length direction Y of the foil 1.

[0054] Implementation Method 2

[0055] A processing apparatus for electrode sheets, see [link / reference] Figure 3 and Figure 9 ,include:

[0056] The slurry dispensing assembly has a gasket 2, which includes a discharge port and two oppositely arranged guide ends 20. The discharge port is located between the two guide ends 20 and is used to deliver slurry to the surface of the foil.

[0057] The control thinning component is located on one side of the outlet and is slidably connected to the slurry dispensing component so that the control thinning component moves back and forth at the outlet along the width direction of the foil at a preset amplitude.

[0058] Preferably, the slurry discharge assembly further includes an upper pressure plate 4 and a lower pressure plate 5. A gasket 2 is disposed between the upper pressure plate 4 and the lower pressure plate 5. The upper pressure plate 4 and the lower pressure plate 5 can clamp the gasket 2. The lower surface of the upper pressure plate 4, the upper surface of the lower pressure plate 5, and the two guide ends 20 together define the discharge port. A flow groove 50 is formed on the surface of the lower pressure plate 5 facing the gasket 2. Inlets are formed at opposite ends of the flow groove 50. The flow groove 50 corresponds to and is close to the discharge port. The slurry flows from the inlet to the discharge port.

[0059] Due to the seamless fit between the upper and lower pressure plates and the gasket 2, the slurry flows out along the discharge port of the gasket 2 and is then sprayed onto the foil to be coated.

[0060] Preferably, the control thinning assembly includes a stop block 3 and a driver. The upper pressure plate 4 and the lower pressure plate 5 have mounting surfaces on the side corresponding to the discharge port of the gasket 2. A slide rail 6 is provided on the mounting surface. The stop block 3 is slidably connected to the slide rail 6. The stop block 3 is connected to the output end of the driver. Driven by the driver, the stop block 3 moves up and down or left and right relative to the gasket 2. The blocking distance of the stop block 3 is consistent with the width of the resulting thinning area. When the stop block 3 covers the discharge port, a concave coating area can be produced, resulting in the second thinning area 12 of Embodiment 1. When the stop block 3 does not cover the discharge port, a convex coating area can be produced. Figure 5 The first thinning zone 11 in the middle.

[0061] Among them, the length of the stop block 3 is greater than or equal to the width of the thinning zone. The length of the stop block 3 can be adjusted according to the actual width of the thinning zone. In addition, the width of the stop block 3 is greater than the thickness of the gasket 2. The stop block 3 is required to completely close the discharge port that needs to be blocked.

[0062] Specifically, the slide rail 6 can be directly embedded into the edge of the upper and lower pressure plates, which increases the moving speed on the one hand and reduces the friction generated by the stop block 3 during operation on the other hand. The overall shape of the stop block 3 can be a cuboid or a triangle, as long as the maximum interception width is located at the discharge port. In addition, the edge of the stop block 3 can be coated with ceramic to prevent metal debris from being mixed into the slurry during sliding.

[0063] Furthermore, by receiving the coating speed signal from the controller and controlling the operation of the driver, the stop 3 can move rapidly. The driver can be a motor, a pneumatic cylinder, or a hydraulic cylinder. During the operation of the device, after setting the corresponding coating speed, the width of a single tab, and the width of adjacent non-tabs, the controller provides the driver with a forward hold time and a backward hold time based on the information. The driver controls the stop 3 to move forward and backward, resulting in a change in the coating width, thereby forming a coating with a regularly irregular concave-convex structure at the edges. By selectively controlling the surface of the foil to form the corresponding coating structure, it is beneficial to subsequently remove the thinning area in the non-tab region, thereby effectively optimizing the electrode structure and improving the quality of the electrode and the battery cell.

[0064] Implementation Method 3

[0065] A method for preparing an electrode sheet, see [link to documentation]. Figures 4-7 This includes the following steps:

[0066] S1. The slurry is conveyed to the surface of the foil 1 along the coating direction, so that the slurry flows from the outlet to the surface of the foil 1, and the slurry forms the required normal material area 10, first thinning area 11 and second thinning area 12 on the surface of the foil 1. The surface of the foil 1 has a first empty foil area 13 and a second empty foil area 14 that are not coated with slurry. The first thinning area 11 and the second thinning area 12 are distributed on opposite sides of the edge of the normal material area 10 along the width direction of the foil 1, so that the first empty foil area 13 corresponds to the first thinning area 11, and the second empty foil area 14 corresponds to the second thinning area 12.

[0067] S2. Remove the first thinning area 11 and the first empty foil area 13 to obtain the desired electrode sheet.

[0068] In step S1, the slurry flows from the outlet of the gasket 2 to the surface of the foil 1. The width of the outlet of the selected gasket 2 is equal to the width of the normal material area 10 + the width of the first thinning area 11 + the width of the second thinning area 12. The width of each thinning area can be H.

[0069] The discharge port is located between the two guide ends 20 of the gasket 2. The guide end 20 located at the edge of the discharge port can guide the slurry to the surface of the foil 1. The baffle 3 can move back and forth at the discharge position of the discharge port.

[0070] Preferably, step S1 further includes: moving the stop block 3 back and forth at the outlet along the width direction X of the foil 1 at a preset amplitude, and forming a first thinning zone 11 and a second thinning zone 12 alternately according to the movement path of the stop block 3 at the outlet.

[0071] Preferably, step S1 further includes: moving the stop block 3 back and forth sequentially along a first direction T1 that approaches the flow guide end 20 and a second direction T2 that moves it away from the flow guide end 20 by a preset amplitude. The first direction T1 and the second direction T2 are opposite, and the first direction T1 and the second direction T2 can be parallel to the surface of the foil 1, such as... Figure 8 As shown, the outlet of the gasket 2 has a guide end 20 at each of its opposite ends.

[0072] When the stop block 3 covers the discharge port, a concave coating area can be produced, resulting in a second thinning area 12. When the stop block 3 does not cover the discharge port, a convex coating area can be produced, resulting in a first thinning area 11.

[0073] Preferably, step S1 further includes: Figures 7-9 As shown, the gasket 2 is clamped between the upper pressure plate 4 and the lower pressure plate 5, so that the slurry flows from the flow groove 50 of the lower pressure plate 5 to the outlet of the gasket 2, thereby controlling the position of the first thinning zone 11 coated on the foil 1 to be cut.

[0074] Preferably, step S1 further includes: controlling the width of the first thinning area 11 by the movement range of the stop block 3, so that the position to be cut has a corresponding first thinning area 11 and a first empty foil area 13.

[0075] Preferably, step S1 further includes: controlling the width of the second thinning area 12 by the movement range of the stop block 3, so that a second empty foil area 14 is formed between the second thinning area 12 and the edge of the foil 1.

[0076] Furthermore, the stop block 3 can be perpendicular to the discharge port of the gasket 2. On the one hand, the stop block 3 does not completely fit the gasket 2; on the other hand, the stop block 3 completely fits the upper pressure plate 4 and the lower pressure plate 5. The width of the stop block 3 can be the width H of the thinning zone, and the lower limit of the height of the stop block 3 is greater than the height of the discharge port.

[0077] Preferably, step S2 further includes: removing the first thinning area 11 and the first empty foil area 13 by laser cutting, so that the normal material area 10, the second thinning area 12 and the second empty foil area 14 of the electrode sheet are retained, thereby greatly reducing the thinning area of ​​the non-electrode area, while not causing excessive waste of slurry.

[0078] In this preparation method, the stop block 3 can control the width of the coating strip by moving forward and backward. The blocking of the stop block 3 can change the coating width and coat the thinned area on the position that needs to be cut in the subsequent process, thereby obtaining a coating structure that reduces the thinned area. Without changing the subsequent process, all thinned areas in the non-tab area are eliminated, and the area of ​​the thinned area is reduced. On the one hand, the edge adhesion of the tab side of the hot-pressed electrode sheet is improved. On the other hand, the overall area of ​​the thinned area is reduced, the designed electrolyte amount is reduced, and the cycle performance of the battery cell is optimized.

[0079] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments described above, and any obvious improvements, substitutions, or modifications made by those skilled in the art based on the present invention are within the scope of protection of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention.

Claims

1. An electrode sheet, characterized in that, include: The foil (1) has a coating area and a plurality of second empty foil areas (14) on at least one surface in the thickness direction of the foil (1), and there is a gap (15) between two adjacent second empty foil areas (14), and the plurality of gaps (15) are spaced apart along the length direction of the foil (1). The coating area includes interconnected normal material areas (10) and multiple second thinning areas (12). The normal material area (10) has a first edge (101) and a second edge (102) arranged alternately along the length direction of the foil (1). The first edge (101) and the second edge (102) are spaced apart along the width direction of the foil (1). The second thinning area (12) is located between the first edge (101) and the second empty foil area (14), the first edge (101) is located at the end of the second thinning area (12) away from the second empty foil area (14), and the second edge (102) is flush with the end of the second thinning area (12) near the second empty foil area (14); A plurality of second thinning zones (12) are arranged at intervals along the edge of the foil (1) along its length direction, and at least a portion of the normal material zone (10) is disposed between two adjacent second thinning zones (12); Along the thickness direction of the foil (1), the thickness of the second thinning zone (12) is less than the thickness of the normal material zone (10).

2. The electrode sheet as described in claim 1, characterized in that: The first edge (101) and the second edge (102) both extend along the length direction of the foil (1), and the first edge (101) and the second edge (102) are parallel to each other along the width direction of the foil (1). The vertical distance between the first edge (101) and the second edge (102) along the width direction of the foil (1) is equal to the dimension of the second thinning area (12) along the width direction of the foil (1).

3. The electrode sheet as described in claim 1, characterized in that: The two adjacent second empty foil areas (14) and the second edge (102) form the notch (15).

4. The electrode sheet according to any one of claims 1 to 3, characterized in that: Along the width direction of the foil (1), the second thinning area (12) corresponds one-to-one with the second empty foil area (14).

5. A method for preparing an electrode sheet, used to prepare the electrode sheet as described in any one of claims 1 to 4, characterized in that, Includes the following steps: S1. The slurry is conveyed to the surface of the foil (1) along the coating direction, so that the slurry flows from the outlet to the surface of the foil (1) and forms the required normal material area (10), first thinning area (11) and second thinning area (12) on the surface of the foil (1). The surface of the foil (1) has a first empty foil area (13) and a second empty foil area (14) without slurry coating. The first thinning area (11) and the second thinning area (12) are distributed on opposite sides of the edge of the normal material area (10) along the width direction of the foil (1), so that the first empty foil area (13) corresponds to the first thinning area (11) and the second empty foil area (14) corresponds to the second thinning area (12). S2. Remove the first thinning zone (11) and the first empty foil zone (13) to obtain the desired electrode.

6. The method for preparing the electrode sheet as described in claim 5, characterized in that, Step S1 further includes: moving the stop (3) back and forth at the outlet along the width direction of the foil (1) at a preset amplitude, and forming a first thinning zone (11) and a second thinning zone (12) alternately according to the movement path of the stop (3) at the outlet.

7. The method for preparing the electrode sheet as described in claim 5 or 6, characterized in that, Step S1 further includes: controlling the position and width of the first thinning area (11) coated on the foil (1) to be cut, so that the position to be cut has a corresponding first thinning area (11) and a first empty foil area (13).

8. The method for preparing the electrode sheet as described in claim 5 or 6, characterized in that, Step S1 further includes: controlling the width of the second thinning zone (12) so that a second empty foil zone (14) is formed between the second thinning zone (12) and the edge of the foil (1).

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