Preparation method and device of carbon-silicon negative electrode material slurry

Abstract

The invention discloses a preparation method and device of carbon-silicon negative electrode material slurry, and relates to the field of preparation methods of carbon-silicon negative electrode material slurry, and the preparation method comprises the following steps: S101: mixing silicon carbon, a conductive agent, CMC dry powder and deionized water to form a mixed material; s102, the mixed material is placed in a ball mill for ball milling; and S103, after ball milling is completed, the carbon-silicon negative electrode material slurry is formed. According to the invention, the carbon-silicon negative electrode material slurry is processed in a ball milling manner, so that the carbon material can uniformly coat silicon particles to form a core-shell structure or an embedded structure, the volume expansion of silicon can be effectively buffered, and the conductivity and stability of the material are improved at the same time.

Description

Technical Field

[0001] The present invention relates to the field of carbon-silicon negative electrode material slurry preparation methods, and in particular to a carbon-silicon negative electrode material slurry preparation method and device. Background Art

[0002] The patent name is: A method for preparing a negative electrode sheet for a lithium battery (patent application number: 202010502133.4), which discloses a method for preparing a negative electrode sheet for a lithium battery. In this method, a slurry needs to be prepared before preparing the negative electrode sheet for a lithium battery, that is, a carbon-silicon negative electrode material slurry; and in this method, the carbon-silicon negative electrode material slurry needs to be added with deionized water three times to improve the stability of the slurry; and it needs to be made into a mud-like material and then mixed and stirred again, which not only improves the stability of the slurry, but also optimizes the slurry viscosity, reduces bubble generation, etc. However, this method is relatively complicated and has low production efficiency.

[0003] Therefore, it is necessary to propose a method and device for preparing carbon-silicon negative electrode material slurry to solve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and device for preparing carbon-silicon negative electrode material slurry, which uses ball milling to process carbon-silicon negative electrode material slurry, which helps to uniformly coat silicon particles with carbon material to form a core-shell structure or an embedded structure, which can effectively buffer the volume expansion of silicon, while improving the conductivity and stability of the material, and at the same time optimizing the slurry viscosity and reducing bubble generation.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing a carbon-silicon negative electrode material slurry, comprising: S101: mixing silicon carbon, conductive agent, CMC dry powder and deionized water to form a mixed material; S102: The mixed material is placed in a ball mill for ball milling. The ball milling process includes: Step 1: Pre-milling stage, add the mixed material into the ball mill and perform preliminary ball milling, the time is set to 1-2 hours; Step 2: Main ball milling stage: after the pre-ball milling is completed, continue with the main ball milling, and the time is set to 4-6 hours; Step 3: Post-processing ball milling stage: after the main ball milling is completed, post-processing ball milling is carried out, and the time is set to 1-2 hours; The ball mill speed is set at 200-300 rpm. S103: After ball milling, a carbon-silicon negative electrode material slurry is formed.

[0006] Preferably, the ball milling process is carried out in vacuum.

[0007] Preferably, during ball milling, the inner lining sheet and the balls on the inner wall of the ball mill are made of silicon carbon.

[0008] Preferably, in the pre-ball milling stage, the ball mill speed is 200 rpm; In the main ball milling stage, the ball mill speed was 300 rpm; In the post-processing ball milling stage, the ball mill speed was 250 rpm.

[0009] Preferably, the ball milling is carried out at room temperature, with the temperature controlled at 20-30 degrees Celsius.

[0010] The present invention also discloses a carbon-silicon negative electrode material slurry preparation device, which is applied to the carbon-silicon negative electrode material slurry preparation method, and further includes: A ball mill base and a ball mill tank body, wherein both ends of the upper surface of the ball mill base are fixedly mounted with support bearing seats, both ends of the ball mill tank body are rotatably mounted on the support bearing seats, and a transmission gear is fixedly mounted on the outer ring of one end of the ball mill tank body; The ball mill tank contains a plurality of balls, which are driven to perform parabolic motion when the ball mill tank rotates, thereby milling the mixed material in the ball mill tank. The ball mill tank body is provided with a tank cover and a vacuum pump; An inner lining is provided on the inner wall of the ball mill tank body. The inner lining is an arc-shaped plate structure. There are multiple inner linings, which are distributed at equal distances. The inner lining is installed on the inner wall of the ball mill tank body through a screw and nut assembly that penetrates the outside of the ball mill tank body.

[0011] Preferably, a guide groove is provided on the inner lining sheet, the guide groove is an arc-shaped groove structure, and the diameter of the guide groove is adapted to the diameter of the ball stone.

[0012] Preferably, the multiple lining sheets in the ball mill tank body are divided into two groups, the guide grooves in the multiple lining sheets in the left group are all facing the middle section of the ball mill tank body, and the guide grooves in the multiple lining sheets in the right group are also all facing the middle section of the ball mill tank body.

[0013] Preferably, there is a sound insulation gap between the outer wall of the lining sheet and the inner wall of the ball mill tank.

[0014] Preferably, the surface of the inner lining sheet is provided with a rough surface, and the rough surface has a plurality of protrusions or depressions.

[0015] Technical effects and advantages of the present invention: Ball milling is used to process the carbon-silicon negative electrode material slurry, which helps the carbon material to evenly coat the silicon particles, forming a core-shell structure or an embedded structure. This can effectively buffer the volume expansion of silicon, while improving the conductivity and stability of the material, while optimizing the slurry viscosity and reducing bubble generation. The present invention adopts silicon carbon material to prepare ball mill balls, and utilizes its wear resistance, chemical stability and thermal stability to solve the problem that traditional ball mill balls are easy to wear and introduce impurities when grinding silicon-based materials. Since the material particle size of the carbon-silicon negative electrode material is uniform, the carbon-silicon negative electrode material can maintain a uniform pore structure, thereby improving the permeability of the electrolyte and the ion transmission efficiency, and ensuring that the active material on the electrode surface is evenly distributed; The ball milling process is carried out in a vacuum. Ball milling under vacuum conditions can effectively reduce the contamination of the material by impurities in the air, improve the purity of the carbon-silicon negative electrode material, and avoid the phenomenon that the presence of impurities may cause an increase in side reactions of the electrode material; and vacuum ball milling can improve the crystallinity and density of the material, thereby improving the electrical conductivity and mechanical strength of the material; The homogenization and stability improvement of nanostructures achieved through ball milling are difficult to achieve with traditional preparation methods; In the present invention, the balls first impact the inner wall of the ball mill in a suspended position near the bottom of the ball mill, which can reduce the impact force on the inner wall of the ball mill and the wear on the inner lining, thereby increasing the service life of the inner lining and reducing the spread of noise. The mixed material is first ground by the impact between the multiple balls; when the balls contact the inner wall of the guide groove, the contact area is large, which increases the grinding contact surface, thereby saving grinding time; There is also a sound insulation gap between the outer wall of the lining sheet and the inner wall of the ball mill tank. The setting of the sound insulation gap can eliminate the noise generated during the ball milling process to a certain extent, and has a good noise reduction effect; The surface of the inner lining sheet can be provided with a rough surface with multiple protrusions or depressions, forming a "honeycomb"-like structure. This structure can make the balls produce tiny vibrations during movement, increase the interaction between the balls and the material, and improve the grinding efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the method for preparing carbon-silicon negative electrode material slurry of the present invention.

[0017] Figure 2 This is a schematic structural diagram of the device for preparing carbon-silicon negative electrode material slurry of the present invention.

[0018] Figure 3 This is a top view of the carbon-silicon negative electrode material slurry preparation device of the present invention.

[0019] Figure 4 This is a cross-sectional view of the device for preparing carbon-silicon negative electrode material slurry of the present invention.

[0020] In the figure: 1. Ball mill base; 2. Ball mill tank; 3. Screw and nut assembly; 4. Tank cover; 5. Transmission gear; 6. Support bearing seat; 7. Vacuum pump; 8. Sound insulation gap; 9. Inner lining; 10. Guide groove. DETAILED DESCRIPTION

[0021] The present invention provides Figure 1-Figure 4 A method and device for preparing a carbon-silicon negative electrode material slurry is shown, and the method for preparing a carbon-silicon negative electrode material slurry includes: Step 1: Mix silicon carbon, conductive agent, CMC dry powder and deionized water to form a mixed material; The second step: placing the mixed material in a ball mill for ball milling, so that the material particle size in the mixed material is uniform. The carbon-silicon negative electrode material prepared using the carbon-silicon negative electrode material slurry with uniform particle size can fit more stably with the copper sheet and is not easy to separate. In addition, during the use of the carbon-silicon negative electrode (during the charging and discharging process), since the material particle size of the carbon-silicon negative electrode material is uniform, the carbon-silicon negative electrode material can maintain a uniform pore structure, thereby improving the permeability of the electrolyte and the ion transfer efficiency, and ensuring that the active material on the electrode surface is evenly distributed.

[0022] The use of ball milling to process carbon-silicon negative electrode material slurry helps the carbon material to evenly coat the silicon particles, forming a core-shell structure or an embedded structure, which can effectively buffer the volume expansion of silicon (the volume expansion rate of silicon can reach more than 300%. This volume change will cause increased internal stress in the electrode, thereby destroying the integrity of the electrode), while improving the conductivity and stability of the material.

[0023] Through ball milling, the surface of silicon particles is nano-sized, reducing the volume expansion effect of silicon during the charging and discharging process. The nanostructured silicon particles are subjected to less stress during expansion, thereby reducing the pulverization and shedding of particles and significantly improving the cycle stability of the electrode; the homogenization of the nanostructure can significantly increase the specific surface area of ​​the material, thereby enhancing the efficiency of lithium ion insertion and extraction.

[0024] The nanostructure homogenization and stability improvement achieved through ball milling are difficult to achieve with traditional preparation methods. It not only improves the electrochemical properties of the material, but also provides a new technical path for the commercial application of high-energy-density lithium-ion batteries.

[0025] The ball milling process needs to be carried out in a vacuum. Ball milling under vacuum conditions can effectively reduce the contamination of the material by impurities in the air (such as oxygen, moisture, etc.), improve the purity of the carbon-silicon negative electrode material, and avoid the phenomenon that the presence of impurities may cause an increase in side reactions of the electrode material; and vacuum ball milling can improve the crystallinity and density of the material, thereby improving the electrical conductivity and mechanical strength of the material.

[0026] The specific process of ball milling includes: (1) Ball milling time 1. Pre-ball milling stage: Add the carbon-silicon negative electrode material (including silicon-carbon, conductive agent, CMC dry powder and deionized water) into the ball mill for preliminary ball milling. The time is set to 1-2 hours. The purpose of this stage is to initially crush and mix the materials.

[0027] 2. Main ball milling stage: After the pre-ball milling is completed, the main ball milling is continued, and the time is set to 4-6 hours. The purpose of this stage is to grind the material to the nanometer level and achieve uniform dispersion.

[0028] 3. Post-processing ball milling stage: After the main ball milling is completed, post-processing ball milling is carried out, and the time is set to 1-2 hours. The purpose of this stage is to further optimize the structure and surface properties of the material.

[0029] (2) Ball milling media 1. Ball mill material: The inner wall of the ball mill tank is provided with an inner lining sheet, which is made of silicon carbon to avoid contamination by metal impurities.

[0030] 2. Grinding media: Silicon carbon with a diameter of 5-1 mm is used as the grinding medium. The density of the ball stone is high, which can provide sufficient grinding force while avoiding contamination of the material.

[0031] 3. Ratio of medium to material: The mass ratio of grinding medium (silicon carbon) to carbon-silicon negative electrode material is 3:1 to 5:1. This ratio can ensure that the material is fully ground and dispersed during the ball milling process. The grinding medium and inner liner are both made of silicon carbon. Even if the grinding medium and inner liner are worn, they will not introduce new impurities into the carbon-silicon negative electrode material slurry.

[0032] It should be noted that the preparation of silicon carbon spherulite requires multiple steps, including raw material proportioning, mixing, molding, sintering, etc. The following is a detailed preparation process and precautions: Step 1: Raw material ratio, the main ingredients include: Silicon source, such as silicon dioxide or nano-silicon powder; Carbon source, such as carbon black, graphite powder or organic carbon source (such as phenolic resin); Binders, such as polyvinyl alcohol (PVA) or silica sol, are used to enhance the adhesion of the material; Additives, such as aluminum oxide or boron carbide, are used to increase the wear resistance and strength of the balls.

[0033] The proportions according to mass percentage include: silicon source (SiO2): 40-60%, carbon source (carbon black or graphite powder): 20-30%, binder (PVA or silica sol): 5-10%, additive (Al2O3 or B4C): 5-10%, other auxiliary ingredients (such as dispersant): 1-5%.

[0034] Step 2: Mixing and ball milling: put the raw materials in the above ratio into a ball mill, add an appropriate amount of deionized water or ethanol as a dispersant, and use the ball mill to mix and ball mill. The ball milling time is 2-4 hours and the speed is 200-300 rpm; The third step is shaping: the milled slurry is sprayed through a spray dryer for granulation. The hot air temperature (150-200 degrees Celsius), the air outlet temperature (80-100 degrees Celsius) and the pressure difference of the spray dryer are controlled. The particle size of the granulated powder is controlled to be 1-3 mm and passed through a 20-mesh sieve. Pressing molding: the granulated powder is pressed into spherical blanks through a mold. The particle size can be selected from 10 mm, 15 mm, 20 mm, etc., with a smooth surface or regular protrusions. The moisture content of the pressed powder is controlled below 0.5%. Step 4: Sintering: Place the pressed green body into a high-temperature sagger, sprinkle with 80-mesh white corundum isolation sand, and send it into a tunnel kiln or tube furnace for sintering. The sintering temperature is 1200-1350 degrees Celsius, and the firing cycle is 24-36 hours. Sintering is carried out in an inert atmosphere (such as argon or nitrogen) to avoid oxidation. After sintering, the balls are naturally cooled to room temperature, cleaned, the isolation sand and burrs on the surface are removed, and polished to improve the surface smoothness of the balls.

[0035] The present invention adopts silicon carbon material to prepare ball mill balls, and utilizes its wear resistance, chemical stability and thermal stability to solve the problems of easy wear and impurity introduction of traditional ball mills when grinding silicon-based materials.

[0036] Through vacuum or inert gas protection ball milling, spray granulation and high temperature sintering and other processes, the preparation process of ball stone is optimized and the quality and performance of ball stone are improved.

[0037] Silicon carbon spherulite is particularly suitable for grinding highly active silicon-based materials such as nano-silicon and silicon oxide. It can significantly improve the purity and performance of the materials and provide a new technical means for the preparation of high-performance lithium-ion battery negative electrode materials.

[0038] (3) Ball milling speed 1. Ball mill speed: The speed of the ball mill is set to 200-300 rpm. This speed range can provide sufficient mechanical energy to enable the material to fully collide and grind in the ball mill.

[0039] 2. Speed ​​adjustment: In the pre-milling stage, the speed can be slightly lower (200 rpm) to avoid over-grinding; in the main milling stage, the speed is increased to 300 rpm to achieve efficient nano-sizing; in the post-processing milling stage, the speed can be appropriately reduced (250 rpm) to optimize the material structure.

[0040] (4) Ball milling temperature 1. Room temperature ball milling: Ball milling is carried out at room temperature, with the temperature controlled at 20-30 degrees Celsius; room temperature ball milling can avoid the impact of high temperature on the material structure and save energy.

[0041] 2. Temperature control measures: During the ball milling process, water cooling or air cooling devices can be used to ensure that the temperature inside the ball mill does not exceed 30 degrees Celsius.

[0042] Ball milling is carried out under vacuum conditions. The vacuum degree setting under vacuum conditions is: During the ball milling process, the vacuum degree in the ball mill is maintained at 10 -3 Pascal to 10 -4 Pascal, this vacuum degree can effectively reduce the contamination of materials by impurities in the air (such as oxygen, moisture, etc.).

[0043] Vacuum maintenance method: Install a vacuum pump in the sealing system of the ball mill to ensure the stability of the vacuum degree in the ball mill by continuous vacuuming.

[0044] The specific steps of vacuum ball milling include: Step 1: Vacuum. After adding carbon silicon negative electrode material and grinding medium (ball stone), close the sealing cover of the ball mill, start the vacuum pump, and extract the air in the ball mill to reach the set vacuum degree.

[0045] Step 2: Ball milling operation. After reaching the set vacuum degree, start the ball mill and perform the ball milling operation according to the above ball milling time, speed and medium ratio.

[0046] Step 3: Nitrogen filling protection. After the ball milling is completed, high-purity nitrogen can be filled into the ball mill to further protect the material from oxidation.

[0047] Surfactants can be added during the ball milling process: During the ball milling process, an appropriate amount of surfactant (such as polyethylene glycol, sodium lauryl sulfate, etc.) can be added. The surfactant can form a protective film on the surface of the material, reduce particle agglomeration, and improve the wettability and dispersibility of the material. The amount of surfactant added is 1%-5% of the mass of the carbon-silicon negative electrode material, and it can also be added according to actual needs.

[0048] refer to Figures 2 to 4As shown in the figure, the ball mill in the present invention includes a ball mill base 1 and a ball mill tank body 2. Support bearing seats 6 are fixedly installed at both ends of the upper surface of the ball mill base 1. Both ends of the ball mill tank body 2 are rotatably set on the support bearing seats 6. A transmission gear 5 is fixedly set at the outer ring of one end of the ball mill tank body 2. A motor, planetary gears and other structures can be set on the ball mill base 1 to drive the transmission gear 5 to rotate, thereby driving the ball mill tank body 2 to rotate. A plurality of balls are stored in the ball mill tank body 2. When the ball mill tank body 2 rotates, the plurality of balls are driven to perform parabolic motion, thereby ball milling the mixed material in the ball mill tank body 2.

[0049] It should be noted that the transmission methods such as motors and planetary gears are conventional transmission mechanisms in the prior art and will not be described in detail here.

[0050] A tank cover 4 is provided on the ball mill tank body 2. When the tank cover 4 is opened, the mixed material in the ball mill tank body 2 can be allowed to enter and exit. One end of the ball mill tank body 2 is connected to a vacuum pump 7. The vacuum pump 7 can be used to evacuate the ball mill tank body 2, thereby maintaining a vacuum state in the ball mill tank body 2.

[0051] An inner lining sheet 9 is provided on the inner wall of the ball mill tank body 2. The inner lining sheet 9 is an arc-shaped plate structure. There are multiple inner lining sheets 9, and the multiple inner lining sheets 9 are distributed at equal distances. The inner lining sheet 9 is installed on the inner wall of the ball mill tank body 2 through a screw and nut assembly 3 that penetrates the outside of the ball mill tank body 2. The screw and nut assembly 3 includes screws and nuts. The connection method of the screw and nut assembly 3 penetrating to the outside of the ball mill tank body 2 can ensure that the surface of the inner lining sheet 9 located inside the ball mill tank body 2 is used more, thereby ensuring the collision area with the balls and materials.

[0052] Furthermore, a guide groove 10 is provided on the inner lining 9. The guide groove 10 is an arc-shaped groove structure, and the diameter of the guide groove 10 is adapted to the diameter of the balls. When the ball mill tank body 2 rotates to drive the balls to move, the balls can rise along the guide groove 10, and when the balls reach the top, they are guided to make parabolic motion in one direction. The multiple inner linings 9 in the ball mill tank body 2 are divided into two groups, the left and right groups. The guide grooves 10 in the multiple inner linings 9 in the left group are all facing the middle section of the ball mill tank body 2, and the guide grooves 10 in the multiple inner linings 9 in the right group are also all facing the middle section of the ball mill tank body 2. This creates a phenomenon in which the balls in the ball mill tank body 2 move in one direction. When the balls make parabolic motion and are about to fall to the bottom of the ball mill tank body 2, the multiple balls first collide with each other and then fall to the bottom of the ball mill tank body 2.

[0053] Based on the fact that the balls in the present invention first produce an impact effect in a suspended position near the bottom of the ball mill tank body 2, the impact force on the inner wall of the ball mill tank body 2 and the wear on the inner lining 9 can be reduced, the service life of the inner lining 9 is increased, and the propagation of noise is reduced, so that the mixed material is first ground by the impact between multiple balls.

[0054] The depth and diameter of the guide groove 10 can also be optimized according to the size of the ball stone, generally with a depth of 3-5 mm and a diameter of 5-10 mm. Based on the adaptation of the guide groove 10 to the ball stone, when the ball stone contacts the inner wall of the guide groove 10, the contact area is large, which increases the grinding contact surface and thus saves grinding time.

[0055] Furthermore, a sound insulation gap 8 is provided between the outer wall of the inner lining 9 and the inner wall of the ball mill tank 2. The provision of the sound insulation gap 8 can eliminate the noise generated during the ball milling process to a certain extent, and has a good noise reduction effect.

[0056] In actual use, the surface of the inner lining sheet 9 may be provided with a rough surface with multiple protrusions or depressions, forming a "honeycomb"-like structure, which can cause the balls to produce tiny vibrations during movement, increase the interaction between the balls and the material, and improve the grinding efficiency.

Claims

1. A method for preparing carbon-silicon negative electrode material slurry, characterized in that: include: S101: mixing silicon carbon, conductive agent, CMC dry powder and deionized water to form a mixed material; S102: The mixed material is placed in a ball mill for ball milling. The ball milling process includes: Step 1: Pre-milling stage, add the mixed material into the ball mill and perform preliminary ball milling, the time is set to 1-2 hours; Step 2: Main ball milling stage: after the pre-ball milling is completed, continue with the main ball milling, and the time is set to 4-6 hours; Step 3: Post-processing ball milling stage: after the main ball milling is completed, post-processing ball milling is carried out, and the time is set to 1-2 hours; The ball mill speed is set at 200-300 rpm. S103: After ball milling, a carbon-silicon negative electrode material slurry is formed.

2. The method for preparing a carbon-silicon negative electrode material slurry according to claim 1, characterized in that: The ball milling process is carried out in vacuum.

3. The method for preparing a carbon-silicon negative electrode material slurry according to claim 1, wherein: During ball milling, the inner lining and ball stones of the ball mill are made of silicon carbon.

4. The method for preparing a carbon-silicon negative electrode material slurry according to claim 1, wherein: in, In the pre-ball milling stage, the ball mill speed was 200 rpm; In the main ball milling stage, the ball mill speed was 300 rpm; In the post-processing ball milling stage, the ball mill speed was 250 rpm.

5. The method for preparing a carbon-silicon negative electrode material slurry according to claim 1, wherein: Ball milling is carried out at room temperature, and the temperature is controlled at 20-30 degrees Celsius.

6. A device for preparing carbon-silicon negative electrode material slurry, characterized by: The method for preparing the carbon-silicon negative electrode material slurry according to any one of claims 1 to 5 further comprises: A ball mill base (1) and a ball mill tank (2), wherein both ends of the upper surface of the ball mill base (1) are fixedly mounted with support bearing seats (6), both ends of the ball mill tank (2) are rotatably mounted on the support bearing seats (6), and a transmission gear (5) is fixedly mounted on the outer ring of one end of the ball mill tank (2); The ball mill tank (2) stores a plurality of balls, and when the ball mill tank (2) rotates, the plurality of balls are driven to perform parabolic motion, thereby ball milling the mixed material in the ball mill tank (2); The ball mill tank body (2) is provided with a tank cover (4) and a vacuum pump (7); An inner lining sheet (9) is provided on the inner wall of the ball mill tank body (2). The inner lining sheet (9) is an arc-shaped plate structure. A plurality of inner lining sheets (9) are provided. The plurality of inner lining sheets (9) are distributed at equal distances. The inner lining sheets (9) are installed on the inner wall of the ball mill tank body (2) through a screw and nut assembly (3) that penetrates the outside of the ball mill tank body (2).

7. The device for preparing carbon-silicon negative electrode material slurry according to claim 6, characterized in that: The inner lining sheet (9) is provided with a guide groove (10), the guide groove (10) is an arc-shaped groove structure, and the diameter of the guide groove (10) is adapted to the diameter of the ball stone.

8. The device for preparing carbon-silicon negative electrode material slurry according to claim 7, characterized in that: The plurality of inner lining sheets (9) in the ball mill tank body (2) are divided into two groups, the left and right groups. The guide grooves (10) in the plurality of inner lining sheets (9) in the left group are all oriented toward the middle section of the ball mill tank body (2), and the guide grooves (10) in the plurality of inner lining sheets (9) in the right group are also all oriented toward the middle section of the ball mill tank body (2).

9. The device for preparing carbon-silicon negative electrode material slurry according to claim 6, characterized in that: A sound insulation gap (8) is provided between the outer wall of the inner lining sheet (9) and the inner wall of the ball mill tank body (2).

10. The device for preparing carbon-silicon negative electrode material slurry according to claim 6, characterized in that: The surface of the inner lining sheet (9) is provided with a rough surface, and the rough surface has a plurality of protrusions or depressions.

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