Preparation method of silicon-carbon negative electrode of solid-state battery

Abstract

The invention relates to the technical field of solid-state batteries, in particular to a preparation method of a silicon-carbon negative electrode of a solid-state battery, which comprises the following steps: A, coating a copper foil; b, carrying out drying treatment on the coated copper foil; c, carrying out trimming treatment on the dried copper foil; d, carrying out rolling treatment on the trimmed copper foil; wherein the coating used in the step A comprises a silicon carbon material, LLTO and a corrosive substance, and the corrosive substance is used for corroding the copper foil so that a rough structure can be generated on the surface of the copper foil. The corrosion substance is added into the coating, the content of the corrosion substance is low, the corrosion substance can just corrode the surface of the copper foil to enable the surface of the copper foil to generate a micron-scale or nano-scale rough structure, and therefore the adhesive force between the coating and the copper foil is improved; and a metallic acid compound formed after the corrosive substance reacts with the copper foil does not have excessive influence on the performance of the coating.

Description

Technical Field

[0001] The present invention relates to the technical field of solid-state batteries, and in particular to a method for preparing a silicon-carbon negative electrode of a solid-state battery. Background Art

[0002] In the existing scheme, when using the negative electrode carbon silicon material doped solid electrolyte LLTO, the coating will fail to reliably and effectively bond the slurry to the negative electrode current collector copper foil, resulting in the negative electrode slurry falling off during the coating process. This phenomenon usually occurs because the surface of the copper foil is too smooth, resulting in a mismatch between the negative electrode slurry and the copper foil.

[0003] The above phenomenon will obviously affect the yield of the negative electrode and undoubtedly increase the production cost. Summary of the invention

[0004] In view of the problems of the prior art, the present invention provides a method for preparing a silicon-carbon negative electrode of a solid-state battery, which improves the adhesion effect between copper foil and coating without affecting the performance of the coating itself.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] The present invention provides a method for preparing a solid-state battery silicon-carbon negative electrode, comprising the following steps:

[0007] A. Coating the copper foil;

[0008] B. Drying the coated copper foil;

[0009] C. Trimming the copper foil after drying;

[0010] D. Roll up the trimmed copper foil;

[0011] The coating used in step A comprises silicon-carbon material, LLTO and a corrosive substance, and the corrosive substance is used to corrode the copper foil so that a rough structure is generated on the surface of the copper foil.

[0012] Furthermore, the corrosive substance is oxalic acid, the mass proportion of oxalic acid in the coating is 0.5-5%, and the oxalic acid is evenly distributed in the coating.

[0013] Further, step A specifically includes:

[0014] A1. Load and transfer copper foil by unwinding;

[0015] A2. Cleaning the surface of the copper foil, and then drying the cleaned copper foil;

[0016] A3. Heating the copper foil so that the temperature of the copper foil reaches a preset value;

[0017] A4. Apply the paint to the surface of the copper foil;

[0018] A5. Transfer the copper foil into the oven and keep it in a horizontal state during the transfer process.

[0019] Furthermore, step A5 further includes:

[0020] The posture of the copper foil is obtained through a visual device. If the posture of the copper foil is horizontal and straight, the current state is maintained; if the copper foil is loose, the traction force on the copper foil is increased;

[0021] During the copper foil transmission process, the temperature of the bottom of the copper foil is measured and hot air is blown.

[0022] Furthermore, step B specifically includes:

[0023] B1. Transfer the copper foil to the oven in mid-air;

[0024] B2. Obtain an image of the copper foil at the entrance of the oven, and obtain the humidity A1 of the coating on the surface of the copper foil based on the thickness and color of the coating in the image;

[0025] B3. Adjust the temperature of the fluid in the oven according to the dryness of the paint and the humidity in the oven.

[0026] Furthermore, step B3 specifically includes:

[0027] B31. Get the air humidity A2 in the oven;

[0028] B32. According to the formula A'=k1*A1+k2*A2, calculate the weighted humidity A';

[0029] B33. If the weighted humidity A' is greater than the preset humidity range, the temperature in the oven is increased and / or the airflow rate in the oven is increased; if the weighted humidity A' is less than the preset humidity range, the temperature in the oven is decreased and / or the airflow rate in the oven is decreased;

[0030] Among them, k1 and k2 are weight coefficients and k1>k2.

[0031] Furthermore, in step B33, if the weighted humidity A' is greater than the preset humidity range, the following steps are performed:

[0032] B34. Get the maximum value of the preset humidity range A max ;

[0033] B35. Through k'=A' / A max , calculate k', where k' is rounded to the first decimal place;

[0034] B36. Adjust the temperature of the oven according to the integer value of k', and adjust the air flow rate in the oven according to the decimal value of k';

[0035] If the weighted humidity A' is less than the preset humidity range, perform the following steps:

[0036] B37. Get the maximum value of the preset humidity range A min ;

[0037] B38. Through k" = A min / A', calculate k", where k" is rounded to the first decimal place;

[0038] B39. Adjust the temperature of the oven according to the integer value of k” and adjust the air flow rate in the oven according to the decimal value of k”.

[0039] Further, step C specifically includes:

[0040] C1. Using a camera to capture a top view of the copper foil, and obtaining the relative position of the coating on the copper foil and the shooting position in the horizontal projection in the image;

[0041] C2. Adjust the positions of the two trimming modules according to the relative positions in C1;

[0042] C3. Cut the two sides of the copper foil by the trimming module so that the coating is located at the center of the cut copper foil and the width of the blank area on both sides of the coating is substantially the same;

[0043] C4. Grind both sides of the trimmed copper foil.

[0044] Furthermore, step C4 specifically includes:

[0045] C41. The copper foil is transferred to a channel, wherein the channel presses the upper and lower surfaces of the blank area of ​​the copper foil;

[0046] C42. Use sandpaper to grind both sides of the copper foil in the channel of the copper foil to reduce the sharp cutting surfaces on both sides of the copper foil caused by cutting.

[0047] Furthermore, in step C3, it also includes:

[0048] C31. Direct the waste formed by cutting into the recycling container;

[0049] C32. Compress the waste in the recycling container;

[0050] C33. Periodically executing step C32 until the density of the compressed waste reaches a certain value, and as the next waste is compressed, the door of the recycling container will compress the waste to push it open, so that the waste is discharged from the waste container;

[0051] C34. The door of the recovery container is reset and the compressed waste is cut off at the same time.

[0052] Beneficial effects of the present invention: The present invention adds a corrosive substance to the coating, and the content of the corrosive substance is low, which can corrode the surface of the copper foil so that the surface of the copper foil produces a rough structure at the micrometer or nanometer level, thereby improving the adhesion between the coating and the copper foil; and the metal acid compound formed by the corrosive substance after reacting with the copper foil will not have too much influence on the performance of the coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a process flow chart of the present invention.

[0054] Figure 2 Schematic diagram of a device for performing step B.

[0055] Figure 3 Schematic diagram of a device for performing step C.

[0056] Figure 4 Schematic diagram of the negative electrode prepared by the present invention.

[0057] Figure numerals: 2—hot air blowing module, 4—oven, 5—visual device, 7—shooting device, 8—trimming module, 9—channel, 10—sandpaper, 12—waste container, 13—compression module, 14—door, 15—copper foil, 16—paint, 17—blank area. DETAILED DESCRIPTION

[0058] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with the embodiments and drawings, and the contents mentioned in the embodiments are not intended to limit the present invention. The present invention is described in detail below in conjunction with the drawings.

[0059] like Figures 1 to 4 As shown, the present invention provides a method for preparing a solid-state battery silicon-carbon negative electrode, comprising the following steps:

[0060] A. coating the copper foil 15;

[0061] B. drying the coated copper foil 15;

[0062] C. trimming the dried copper foil 15;

[0063] D. rolling up the trimmed copper foil 15;

[0064] The coating 16 used in step A includes silicon-carbon material, LLTO and a corrosive substance, and the corrosive substance is used to corrode the copper foil 15 so that a rough structure is generated on the surface of the copper foil 15 .

[0065] In this embodiment, the corrosive substance is oxalic acid, the mass proportion of oxalic acid in the coating 16 is 0.5-5%, and the oxalic acid is evenly distributed in the coating 16 .

[0066] That is, during coating, after the coating 16 containing oxalic acid is coated on the copper foil 15, the oxalic acid in the coating 16 corrodes the surface of the copper foil 15, so that a rough structure with uneven surfaces is formed on the surface of the copper foil 15, thereby improving the adhesion between the coating 16 and the copper foil 15; and the substance formed after the reaction of oxalic acid and the copper foil 15 will not affect the performance of the coating 16, and also ensures the quality of the silicon-carbon negative electrode prepared by the present invention.

[0067] It should be noted that the above-mentioned mass ratio is the optimal solution obtained after multiple verifications, that is, at this mass ratio, a rough structure sufficient to improve adhesion can be etched out, the copper foil 15 can be prevented from being corroded, and the content of the compound generated by the reaction of oxalic acid and the copper foil 15 can be ensured to be low so as not to affect the actual function of the coating 16.

[0068] In this embodiment, step A specifically includes:

[0069] A1. Load and transfer the copper foil 15 by unwinding;

[0070] A2. The surface of the copper foil 15 is cleaned and then the cleaned copper foil 15 is dried;

[0071] A3. The copper foil 15 is heated so that the temperature of the copper foil 15 reaches a preset value;

[0072] A4. Apply the coating 16 to the surface of the copper foil 15;

[0073] A5. Transfer the copper foil 15 to the oven 4 and keep the copper foil 15 in a horizontal state during the transfer process.

[0074] That is, before coating, the surface of the copper foil 15 to be coated needs to be cleaned and dried. The cleaning can be achieved by using a nozzle as a cleaning module 1 to spray ionized water on the copper foil 15; and the drying can be achieved by electrically heating the copper foil 15 or blowing hot air on the copper foil 15. If a hot air blowing module 2 is used to blow hot air on the copper foil 15, the drying process in step A2 and the heating process in step A3 are achieved at the same time, which is beneficial to improving efficiency.

[0075] After coating, the copper foil 15 needs to be kept horizontally fed into the oven 4, and the copper foil 15 needs to be kept horizontally in the oven 4 to ensure that the fluid coating 16 remains on the copper foil 15 before drying and does not flow, thereby ensuring that the coating 16 has a uniform thickness and that the degree of corrosion of the coating 16 at each position of the copper foil 15 by oxalic acid is basically the same.

[0076] Specifically, step A5 also includes:

[0077] The posture of the copper foil 15 is obtained by the visual device 5. If the posture of the copper foil 15 is horizontal and straight, the current state is maintained; if the copper foil 15 is loose, the traction force on the copper foil 15 is increased;

[0078] During the transportation of the copper foil 15 , the temperature of the bottom of the copper foil 15 is measured and hot air is blown.

[0079] That is, after coating, the posture of the copper foil 15 is obtained through the visual device 5, and the traction force of the traction mechanism on the copper foil 15 is adjusted to ensure that the copper foil 15 is always in a straight state, so as to ensure that the coating 16 does not flow. In addition, the present invention needs to measure the temperature of the copper foil 15. If the temperature of the copper foil 15 is lower than the preset temperature, hot air is blown on the non-coated surface of the copper foil 15 to ensure that before entering the oven 4, sufficient reaction occurs between oxalic acid and the copper foil 15, so as to achieve the desired rough structure before the water in the coating 16 is evaporated, and the reaction rate of oxalic acid is ensured by the high temperature.

[0080] In this embodiment, step B specifically includes:

[0081] B1. Transfer the copper foil 15 to the oven 4 in mid-air;

[0082] B2. Obtain an image of the copper foil 15 at the entrance of the oven 4, and obtain the humidity A1 of the coating 16 on the surface of the copper foil 15 according to the thickness and color of the coating 16 in the image;

[0083] B3. Adjust the temperature of the fluid in the oven 4 according to the degree of dryness of the coating 16 and the humidity in the oven 4.

[0084] In actual use, step B3 specifically includes:

[0085] B31 obtains the air humidity A2 in the oven 4;

[0086] B32. According to the formula A'=k1*A1+k2*A2, calculate the weighted humidity A';

[0087] B33. If the weighted humidity A' is greater than the preset humidity range, the temperature in the oven 4 is increased or / and the airflow rate in the oven 4 is increased; if the weighted humidity A' is less than the preset humidity range, the temperature in the oven 4 is decreased or / and the airflow rate in the oven 4 is decreased;

[0088] Among them, k1 and k2 are weight coefficients and k1>k2.

[0089] The visual device 5 may include at least two cameras. For example, two cameras are used, one of which captures a top view of the copper foil 15, and the other captures a side view of the copper foil 15. That is, the present invention captures an image of the copper foil 15 through the visual device 5, analyzes the color and thickness of the coating 16 in the image to determine the humidity of the coating 16 on the surface of the copper foil 15 (i.e., the current water content in the coating 16), and performs weight processing in combination with the humidity in the oven 4, thereby obtaining a weighted humidity A'. The present invention adjusts the temperature and airflow rate of the oven 4 according to the weighted humidity A', so that the coating 16 can be dried just right when the copper foil 15 leaves the oven 4 and will not break due to over-baking.

[0090] The weighted humidity A' of the present invention is calculated by combining the water content of the coating 16 itself and the humidity inside the oven 4. The specific weight coefficient can be simulated and calculated based on the actual coating 16 ratio, the length of the oven 4 and other parameters, which will not be repeated here.

[0091] Specifically, in step B33, if the weighted humidity A' is greater than the preset humidity range, the following steps are performed:

[0092] B34. Get the maximum value of the preset humidity range A max ;

[0093] B35. Through k'=A' / A max , calculate k', where k' is rounded to the first decimal place;

[0094] B36. Adjust the temperature of the oven 4 according to the integer value of k', and adjust the air flow rate in the oven 4 according to the decimal value of k'.

[0095] For example, when the calculated k' is 1.3, 1 is the temperature level of the oven 4 to be increased, and 3 is the level of the airflow rate to be increased. In this embodiment, an oven 4 temperature level is 5-10°C, and an airflow level is half of the initial airflow rate level, and the adjustable airflow levels are divided into three: 0-3 for no adjustment, 4-6 for adjusting one airflow level, and 7-9 for adjusting two airflow levels. Under the adjustment method of the present invention, it can be ensured that the temperature rise will not be too large, thereby avoiding the coating 16 from being denatured due to excessive temperature; in addition, the change in airflow is mainly to achieve the disturbance of the gas inside the oven 4, that is, to make the gas inside the oven 4 flow faster, so as to blow away the water vapor in the oven 4 as soon as possible, so as to avoid affecting the evaporation of water in the coating 16. Usually, the airflow in the oven 4 will not directly act on the coating 16 to avoid uneven distribution of the coating 16; the airflow will be blown to the coating 16 only when the copper foil 15 is about to leave the oven 4. At this time, the coating 16 is basically solidified and will not be deformed by the airflow. The airflow will only take away water faster and more directly to ensure the baking effect.

[0096] In this embodiment, if the weighted humidity A' is less than the preset humidity range, the following steps are performed:

[0097] B37. Get the maximum value of the preset humidity range A min ;

[0098] B38. Through k" = A min / A', calculate k", where k" is rounded to the first decimal place;

[0099] B39. Adjust the temperature of the oven 4 according to the integer value of k”, and adjust the air flow rate in the oven 4 according to the decimal value of k”.

[0100] That is, when the humidity is less than the preset range, the adjustment method of the present invention is to reduce the temperature of the oven 4 and reduce the airflow rate, so as to reduce the drying rate of the coating 16 and avoid cracking of the coating 16 due to over-fast drying. In this process, the integer value and decimal value of k" represent the reduced temperature level of the oven 4 and the reduced airflow rate value, respectively.

[0101] It should be noted that the oven 4 of the present invention can be a multi-stage oven 4, and each stage of the oven 4 independently performs the execution step B3 once, so as to ensure that the coating 16 of the copper foil 15 of the present invention is more flexible in drying. It should be noted that the execution step B3 is a linear execution. Taking the temperature increase as an example, when the temperature is increased from A℃ to (A+10)℃, it is achieved within a specified time (for example, 30s) to ensure that the temperature does not change suddenly and cause the coating 16 to be affected; and the specified time is determined by the transmission rate of the copper foil 15.

[0102] When the oven 4 is of multi-stage type, only the last one or two stages are used for winding transmission of the copper foil 15 for drying, and the front four stages of the oven are all horizontal transmission ovens 4, thereby achieving the effect of saving space.

[0103] In this embodiment, step C specifically includes:

[0104] C1. A top view of the copper foil 15 is captured by the camera 7 to obtain the relative position of the coating 16 on the copper foil 15 and the shooting position in the horizontal projection in the image;

[0105] C2. According to the relative position in C1, adjust the position of the two trimming modules 8;

[0106] C3. The copper foil 15 is cut on both sides by the trimming module 8 so that the coating 16 is located at the center of the copper foil 15 after cutting, and the blank area 17 on both sides of the coating 16 has substantially the same width;

[0107] C4. Grinding the two sides of the trimmed copper foil 15.

[0108] That is, the present invention does not need to correct the copper foil 15 before and after coating, but the copper foil 15 is cut after coating to achieve the effect of controlling the width of the blank area 17. The trimming module 8 is a conventional structure, and its position is adjusted by a motor screw structure. Since the offset of the copper foil 15 usually changes gradually rather than suddenly, the position of the trimming module 8 can be adjusted during the actual cutting process. Since the present invention does not correct the copper foil 15 before coating, it reduces excessive pulling on the copper foil 15, which is beneficial to avoid the breakage of the copper foil 15 and ensures the continuity of the process.

[0109] In this embodiment, step C4 specifically includes:

[0110] C41. The copper foil 15 is transferred to a channel 9, wherein the channel 9 presses the upper and lower surfaces of the copper foil 15 leaving the blank area 17;

[0111] C42. Use sandpaper 10 to grind both sides of the copper foil 15 in the channel 9 of the copper foil 15 to reduce the sharp cutting surfaces on both sides of the copper foil 15 caused by cutting.

[0112] That is, after the copper foil 15 is cut, both sides thereof will have sharp cutting surfaces. At this time, the present invention performs a grinding process on the cutting surfaces to passivate the cutting surfaces, thereby preventing the cutting surfaces from scratching other components during subsequent installation and improving stability.

[0113] In actual use, the sanding paper 10 and the trimming module 8 are adjusted by the same structure so that the two are adjusted synchronously, ensuring that the copper foil is not excessively squeezed during trimming.

[0114] It should be noted that the present invention can be applied to silicon-carbon anodes that can be applied without cutting, and can also be applied to silicon-carbon anodes that need cutting. If cutting is required, a blank area 17 will be formed between adjacent coating areas during coating, and the blank area 17 is the cutting position; and the trimming and polishing mentioned in the present invention are to process the copper foil 15 after cutting.

[0115] Specifically, in step C3, it also includes:

[0116] C31. Direct the waste formed by cutting into the recycling container;

[0117] C32. Compress the waste in the recycling container;

[0118] C33. Periodically executing step C32 until the density of the compressed waste reaches a certain value, as the next waste is compressed, the door 14 of the recycling container will compress the waste to push open, so that the waste is discharged from the waste container 12;

[0119] C34. The door 14 of the recovery container is reset and the compressed waste is cut off at the same time.

[0120] The waste container 12 compresses the waste through the compression module 13 with the cylinder as the power source. Specifically, the waste is guided into the waste container 12 by the guide wheel. Since the waste is thin and in strip shape, it will be continuously twisted and folded by the space in the waste container 12 after entering the waste container 12, and become a loose structure. When the waste in the waste container 12 accumulates to a certain extent, the compression module 13 is operated to compact the waste. The action stroke of the compression module 13 is fixed. After multiple compressions, the waste is compressed. After that, the waste material eventually becomes a dense structure, and its length reaches a certain value, so that when the compression module 13 is subsequently actuated, the waste material will press against the door 14 and make most of the force of the compression module 13 act on the door 14. When the force reaches the threshold of the door 14, the door 14 can be pushed open, thereby pushing the waste material away from the waste container 12 and sending it to the conveyor belt for transmission; and when the compression module 13 is reset, the waste material has been transmitted a certain distance, at which time the door 14 will be reset under the corresponding structure, cutting off the waste material and reclosing the waste container 12.

[0121] Through the setting of steps C31-C34, automatic compression and collection of waste materials formed by trimming are realized. The compression module 13 can periodically compress the waste materials and maintain the compression action for a certain period of time after each compression of the waste materials to ensure that the waste materials are deformed, thereby ensuring that the waste materials will tend to be dense after multiple compressions to facilitate unloading and recycling.

[0122] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention is disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes by using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent changes and modifications made to the above embodiments according to the technology of the present invention are within the scope of the technical solution of the present invention without departing from the content of the technical solution of the present invention.

Claims

1. A method for preparing a solid-state battery silicon-carbon negative electrode, characterized in that: The following steps are involved: A. Coating the copper foil; B. Drying the coated copper foil; C. Trimming the copper foil after drying; D. Roll up the trimmed copper foil; The coating used in step A comprises silicon-carbon material, LLTO and a corrosive substance, and the corrosive substance is used to corrode the copper foil so that a rough structure is generated on the surface of the copper foil.

2. The method for preparing a solid-state battery silicon-carbon negative electrode according to claim 1, characterized in that: The corrosive substance is oxalic acid, the mass proportion of oxalic acid in the coating is 0.5-5%, and the oxalic acid is evenly distributed in the coating.

3. The method for preparing a solid-state battery silicon-carbon negative electrode according to claim 1, characterized in that: Step A specifically includes: A1. Load and transfer copper foil by unwinding; A2. Cleaning the surface of the copper foil, and then drying the cleaned copper foil; A3. Heating the copper foil so that the temperature of the copper foil reaches a preset value; A4. Apply the paint to the surface of the copper foil; A5. Transfer the copper foil into the oven and keep it in a horizontal state during the transfer process.

4. The method for preparing a solid-state battery silicon-carbon negative electrode according to claim 3, characterized in that: Step A5 further includes: The posture of the copper foil is obtained through a visual device. If the posture of the copper foil is horizontal and straight, the current state is maintained; if the copper foil is loose, the traction force on the copper foil is increased; During the copper foil transmission process, the temperature of the bottom of the copper foil is measured and hot air is blown.

5. The method for preparing a solid-state battery silicon-carbon negative electrode according to claim 1, characterized in that: Step B specifically includes: B1. Transfer the copper foil to the oven in mid-air; B2. Obtain an image of the copper foil at the entrance of the oven, and obtain the humidity A1 of the coating on the surface of the copper foil based on the thickness and color of the coating in the image; B3. Adjust the temperature of the fluid in the oven according to the dryness of the paint and the humidity in the oven.

6. The method for preparing a solid-state battery silicon-carbon negative electrode according to claim 5, characterized in that: Step B3 specifically includes: B31. Get the air humidity A2 in the oven; B32. According to the formula A'=k1*A1+k2*A2, calculate the weighted humidity A'; B33. If the weighted humidity A' is greater than the preset humidity range, the temperature in the oven is increased and / or the airflow rate in the oven is increased; if the weighted humidity A' is less than the preset humidity range, the temperature in the oven is decreased and / or the airflow rate in the oven is decreased; Among them, k1 and k2 are weight coefficients and k1>k2.

7. The method for preparing a solid-state battery silicon-carbon negative electrode according to claim 6, characterized in that: In step B33, if the weighted humidity A' is greater than the preset humidity range, the following steps are performed: B34. Get the maximum value of the preset humidity range A max ; B35. Through k'=A' / A max , calculate k', where k' is rounded to the first decimal place; B36. Adjust the temperature of the oven according to the integer value of k', and adjust the air flow rate in the oven according to the decimal value of k'; If the weighted humidity A' is less than the preset humidity range, perform the following steps: B37. Get the maximum value of the preset humidity range A min ; B38. Through k" = A min / A', calculate k", where k" is rounded to the first decimal place; B39. Adjust the temperature of the oven according to the integer value of k” and adjust the air flow rate in the oven according to the decimal value of k”.

8. The method for preparing a solid-state battery silicon-carbon negative electrode according to claim 1, characterized in that: Step C specifically includes: C1. photographing a top view of the copper foil by a photographing device to obtain the relative position of the coating on the copper foil and the photographing position in the horizontal projection in the image; C2. Adjust the positions of the two trimming modules according to the relative positions in C1; C3. Cut the two sides of the copper foil by the trimming module so that the coating is located at the center of the cut copper foil, and the width of the blank area on both sides of the coating is substantially the same; C4. Grind both sides of the trimmed copper foil.

9. The method for preparing a solid-state battery silicon-carbon negative electrode according to claim 8, characterized in that: Step C4 specifically includes: C41. The copper foil is transferred to a channel, wherein the channel presses the upper and lower surfaces of the blank area of ​​the copper foil; C42. Use sandpaper to grind both sides of the copper foil in the channel of the copper foil to reduce the sharp cutting surfaces on both sides of the copper foil caused by cutting.

10. The method for preparing a solid-state battery silicon-carbon negative electrode according to claim 8, characterized in that: In step C3, it also includes: C31. Direct the waste formed by cutting into the recycling container; C32. Compress the waste in the recycling container; C33. Periodically executing step C32 until the density of the compressed waste reaches a certain value, and as the next waste is compressed, the door of the recycling container will compress the waste to push it open, so that the waste is discharged from the waste container; C34. The door of the recovery container is reset and the compressed waste is cut off at the same time.

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