Carbon-silicon negative electrode material slurry preparation device and preparation method

Abstract

The present application relates to lithium battery material production technical field, specifically to a kind of carbon silicon negative material slurry preparation device and preparation method, including stirring tank, the bottom of the stirring tank is provided with discharge pipe, tank cover is arranged on the stirring tank, further including motor, stirring assembly and connecting component, the motor is set on tank cover, the stirring assembly is set in stirring tank and is connected with motor, the stirring assembly includes helical blade one and helical blade two, the helical blade one and helical blade two are connected by connecting component, motor is powered on and drives helical blade one forward high-speed rotation.The stirring assembly and connecting component of the present application are set, the reverse differential rotation of helical blade one and helical blade two can be realized, while constructing strong axial circulation flow field, in combination with the annular plate above liquid surface horn, slurry is forced real-time filmization expansion, the effective stripping of deep layer micro-bubble is realized, the production efficiency is improved while also ensuring product quality.

Description

Technical Field

[0001] This invention relates to the field of lithium battery material production technology, specifically to a carbon-silicon anode material slurry preparation apparatus and preparation method. Background Technology

[0002] Methods or devices for directly converting chemical energy into electrical energy, such as battery packs, are the most important key technologies for new energy electric vehicles. Before preparing silicon-carbon anode sheets for lithium batteries, silicon-carbon anode slurry needs to be prepared. The quality of its preparation directly determines the spatial distribution of active materials, conductive agents, and binders at the microscale. For silicon-carbon anode slurry, the uniformity of the slurry not only affects the specific capacity of the electrode sheet, but also determines whether the expansion stress during charging and discharging can be effectively absorbed.

[0003] Existing silicon-carbon anode material slurry preparation devices require multiple additions of deionized water during the preparation process to improve slurry stability, and necessitate further mixing and stirring after forming a slurry-like material. However, this preparation process and method are quite complex, severely limiting production efficiency. To address these issues, existing technologies offer relatively good solutions, such as the silicon-carbon anode material slurry preparation method and apparatus disclosed in CN120709294B. This method uses ball milling to process the silicon-carbon anode slurry, which helps the carbon material uniformly coat the silicon particles, ensuring the conductivity and stability of the silicon-carbon anode material while also improving production efficiency. However, the following drawbacks still exist: after the silicon-carbon anode material slurry is prepared, it requires vacuum degassing. However, because the deep microbubbles inside the silicon-carbon anode slurry are difficult to float to the surface through the high-viscosity matrix under negative pressure, if these microbubbles cannot be suppressed or efficiently removed in the preparation device, the coated electrode will exhibit defects such as pinholes and fish-scale spots, severely affecting product quality.

[0004] Therefore, in order to solve the above problems, a carbon silicon anode material slurry preparation device and preparation method are proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a device and method for preparing silicon-carbon anode material slurry, solving the problem that the failure to promptly and effectively remove microbubbles generated during the preparation of silicon-carbon anode material slurry can seriously affect product quality. Through the designed stirring and connecting components, the reverse differential rotation of helical blades one and two can be achieved. While constructing a strong axial circulating flow field, combined with a trumpet-shaped annular plate above the liquid surface, the slurry is forced to expand into a thin film in real time, effectively removing deep microbubbles, improving production efficiency while ensuring product quality.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A silicon-carbon anode material slurry preparation device includes a stirring tank with a discharge pipe at the bottom and a tank cover. It also includes a motor, a stirring assembly, and a connecting assembly. The motor is mounted on the tank cover, and the stirring assembly is located inside the stirring tank and connected to the motor. The stirring assembly includes a first spiral blade and a second spiral blade, which are connected by the connecting assembly. When the motor is energized, the first spiral blade rotates at high speed in the forward direction, conveying the slurry at the center of the stirring tank from bottom to top above the liquid surface. When the first spiral blade rotates at high speed in the forward direction, the second spiral blade rotates at low speed in the reverse direction via the connecting assembly, conveying the slurry near the inner wall of the stirring tank from top to bottom below the liquid surface.

[0007] Preferably, the stirring assembly further includes a rotating rod and a guide tube. The rotating rod is located at the output end of the motor and extends through the tank cover to the interior of the stirring tank. The first spiral blade is fixedly sleeved on the rotating rod. The second spiral blade is coaxial with the first spiral blade and slides against the inner wall of the stirring tank. The guide tube is coaxially sleeved with the spiral blade. The second spiral blade is fixedly sleeved with the outer wall of the guide tube and has the same spiral direction as the first spiral blade.

[0008] It is known that air bubbles in a liquid will automatically float to the surface under the action of buoyancy. However, since the residual air bubbles in the silicon-carbon anode material slurry are usually micron-sized, the buoyancy generated by these micron-sized air bubbles is very small, making it impossible for them to float in the high-viscosity slurry. Although existing technologies can install a vibration motor on the outside of the mixing tank and use vibration to vent air, the slurry has a large internal friction. After the mechanical waves generated by the external vibration motor penetrate the mixing tank and enter the slurry, the energy of the mechanical waves will be severely attenuated and converted into tiny heat energy and dissipated. This can only cause a thin layer of slurry close to the inner wall of the mixing tank to vibrate slightly, while the deep slurry inside the mixing tank will not be affected by the vibration motor. As a result, the deep air bubbles still cannot be discharged, which will also affect the product quality. Therefore, this solution is adopted. The system utilizes a motor, spiral blade one, spiral blade two, and a guide pipe to transport slurry from the bottom of the mixing tank upwards through the guide pipe to above the liquid surface. A negative pressure is created at the bottom of the guide pipe, which, in conjunction with the negative pressure below the liquid surface, transports slurry outside the guide pipe downwards. This allows the slurry inside the mixing tank to be continuously transported upwards for circulation. As a result, slurry carrying microbubbles is automatically vented after being transported above the liquid surface, thus ensuring product quality.

[0009] Preferably, the connecting assembly includes a central gear, a gear ring, a transmission gear, and a mounting bracket. The central gear is fixedly sleeved on the rotating rod, the gear ring is sleeved with the central gear, the transmission gear is meshed between the central gear and the gear ring, the mounting bracket is fixedly installed at the bottom of the can lid and rotatably sleeved with the gear ring through a sealed bearing, the mounting bracket is provided with a mounting rod, the mounting rod is rotatably sleeved with the transmission gear, and the side wall of the gear ring has a circumferential array of multiple connecting rods, the connecting rods being fixedly connected to the spiral blade.

[0010] Since spiral blade one and spiral blade two are coaxial and work independently, although two separate drive sources can be used to drive spiral blade one and spiral blade two, this would result in higher manufacturing and maintenance costs for the entire device. Furthermore, if the installation positions of the two drive sources are asymmetrical, it would cause a shift in the overall center of gravity of the mixing tank, resulting in significant vibrations when spiral blade one and spiral blade two rotate. This would affect the stability of the connection between spiral blade one and spiral blade two and their corresponding power sources, thereby impacting the service life of the equipment. Therefore, this solution is adopted. By using a central gear, gear ring, and transmission gear, the first and second spiral blades can rotate synchronously in opposite directions during motor operation. Since the spiral directions of the first and second spiral blades are the same, the central gear, gear ring, and transmission gear allow the second spiral blade to rotate at a speed lower than the first, in the opposite direction. The shearing force generated by this reverse rotation better breaks up agglomerates in the silicon carbide material, resulting in a more uniform mixture of conductive agent, binder, and active material. Furthermore, the sliding contact between the second spiral blade and the inner wall of the mixing tank acts as a "wall scraper," continuously carrying the slurry adhering to the inner wall of the mixing tank downwards during continuous rotation, allowing it to re-enter the circulation. During this process, the low-speed rotation of the second spiral blade ensures stable pressure and effective scraping against the inner wall of the mixing tank, preventing localized overheating caused by high-speed friction and further guaranteeing product quality.

[0011] Preferably, the guide tube includes a vertical tube and a tapered tube fixedly connected from top to bottom. The upper port diameter of the tapered tube is smaller than the lower port diameter. The upper end of the spiral blade is higher than the upper end of the vertical tube. The upper end of the vertical tube is located above the liquid surface.

[0012] By adopting the above scheme, due to the high solid content, high viscosity, and extremely poor fluidity of the silicon carbide anode slurry, the tapered design of the conical tube (narrower at the top and wider at the bottom) can increase the material extraction radius at the bottom of the guide tube, thereby effectively converging the slurry stagnant at the bottom corner of the mixing tank towards the center, solving the problem of some slurry being difficult to circulate in the dead corner at the bottom of the mixing tank. At the same time, the vertical tube is used to isolate the slurry inside the tube from the external flow field, forming an independent upward channel inside the vertical tube. This avoids the upward conveying of slurry from colliding and canceling out the downward flowing slurry from all sides in the middle area, greatly improving the upward conveying efficiency of the slurry. Furthermore, since the height of the upper end of the vertical tube is higher than the liquid level, the slurry can fall downward after flowing out from the upper end of the vertical tube, causing a sudden reduction in the pressure on the tiny bubbles in this part of the slurry, thereby dispersing and expelling the tiny bubbles.

[0013] Preferably, the upper outer wall of the vertical pipe is fixedly fitted with a funnel-shaped annular plate, the annular plate being located above the liquid surface, and the diameter of the two ends decreasing from top to bottom.

[0014] It is known that silicon carbide anode slurry has high viscosity, and the microbubbles experience significant matrix resistance, making it difficult for them to automatically dissipate from deeper layers using their own buoyancy. Even if the slurry is transported above the liquid surface by the first spiral blade, the bubbles will still be trapped inside the slurry clumps. Therefore, this solution is adopted. Through the annular plate, the slurry flows from the upper end of the vertical pipe to the upper surface of the annular plate, preventing this portion of the slurry from falling and directly mixing with the original slurry. Because the annular plate is funnel-shaped, the slurry, after flowing to the upper surface of the annular plate, will gather towards the central axis of the annular plate under its own gravity. Furthermore, since the annular plate is fixedly fitted onto the vertical pipe and rotates with the second spiral blade, the centrifugal force during rotation allows the slurry gathered at the center of the upper surface of the annular plate to diffuse outwards until it falls back into the original slurry. During this process, the slurry on the upper surface of the ring plate is smoothly re-in contact with the liquid surface through a "spreading-overflowing" method, which keeps the liquid surface stable to avoid the generation of new bubbles. At the same time, it allows the tiny bubbles in the slurry flowing on the upper surface of the ring plate to come into direct contact with the air, thereby eliminating the tiny bubbles in that part of the slurry and further ensuring product quality.

[0015] Preferably, the inner wall of the tapered tube has a circumferential array of multiple spiral grooves, and the spiral direction of the spiral grooves is opposite to the spiral direction of the first spiral blade.

[0016] By adopting the above scheme, during the high-speed rotation of the spiral blade, the slurry can be driven to move along its rotation direction. At this time, the spiral groove opened on the inner wall of the conical tube will physically impede and guide the slurry. Utilizing the synergistic effect of the two, an extremely high-intensity shear field is formed between the spiral blade and the inner wall of the vertical tube, thereby effectively breaking up micron-sized agglomerates. Compared with a smooth inner wall, the time required to reach the fineness index of the slurry can be significantly shortened, thereby improving the preparation efficiency.

[0017] Preferably, the second spiral blade is disposed below the annular plate and below the liquid surface inside the mixing tank.

[0018] It is known that silicon-carbon particles are prone to agglomeration during the preparation of silicon-carbon anode slurry, hence this approach is adopted. When the spiral blade rotates at high speed and drives the slurry upward, the slurry is subjected to tangential force. As the slurry rotates and rises, it generates strong counter-current friction and eddies with the material in the spiral groove. Through counter-current shearing, the tiny agglomerates in the slurry can be broken up more effectively, thereby improving the uniformity of the slurry.

[0019] A method for preparing a silicon-carbon anode material slurry includes the following steps: S1. Add the preparation material into the mixing tank through the feeding port and start the motor; S2. The motor drives the first and second spiral blades to rotate. The second spiral blade transports the slurry carrying tiny air bubbles below the liquid surface to the bottom of the mixing tank, while the first spiral blade transports the slurry that has gathered at the bottom of the mixing tank and carries tiny air bubbles upward to the top of the liquid surface. S3. The slurry, which is conveyed to the top of the liquid surface and carries tiny air bubbles, falls onto the surface of the annular plate and spreads out to release air as the annular plate rotates, before returning to the slurry below the annular plate.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Through the set stirring and connecting components, the high-speed rotating spiral blades forcefully transport the deep slurry in the center to above the liquid surface. The centrifugal force generated by the rotation of the funnel-shaped annular plate forces the slurry to expand into a thin film, which greatly increases the contact area between the slurry and the air. This causes the air bubbles that were originally trapped deep in the viscous slurry to break and be discharged rapidly during the pressure reduction and spreading process. This achieves active and efficient stripping of deep micro bubbles, thereby effectively ensuring product quality.

[0021] 2. Through the set stirring and connecting components, the connecting components realize the forward high-speed rotation of the first spiral blade and the reverse low-speed rotation of the second spiral blade, forming an extremely high-intensity countercurrent shear field in the mixing tank. This effectively breaks up the micron-sized agglomerates in the silicon carbide anode material slurry, making the active material and conductive agent mix more evenly. At the same time, the strong shear and efficient circulation flow field are constructed by the reverse differential rotation of the double spirals, which fundamentally solves the problem of agglomeration and retention of high-viscosity slurry.

[0022] 3. By sliding the counter-rotating spiral blades against the inner wall of the mixing tank, a continuous "wall scraping" effect is achieved, constantly bringing the slurry close to the wall back into the circulating flow field. This not only enhances the overall axial circulation effect, but also effectively avoids slurry deterioration caused by local overheating through low-speed friction, ensuring that the final slurry is free of air bubbles. This eliminates defects such as pinholes and fish scale spots generated during the coating process from the source, improving production yield while ensuring the consistency of lithium battery materials. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0024] Figure 2 For the present invention Figure 1 A partial cross-sectional structural diagram.

[0025] Figure 3 This is a schematic diagram of the connection structure of the motor, stirring assembly, and connecting assembly of the present invention.

[0026] Figure 4 For the present invention Figure 3 Enlarged view of part A in the middle section.

[0027] Figure 5 This is a schematic diagram of the connection structure between the gear ring, the first helical blade, and the second helical blade of the present invention.

[0028] Figure 6 This is a schematic diagram of the planar cross-sectional connection structure of the vertical tube, the spiral blade, and the annular plate of the present invention.

[0029] In the diagram: 1. Mixing tank; 11. Discharge pipe; 2. Tank cover; 21. Negative pressure extraction pipe; 22. Feed port; 3. Motor; 4. Mixing assembly; 41. Spiral blade one; 42. Spiral blade two; 43. Rotating rod; 44. Guide pipe; 441. Vertical pipe; 442. Conical pipe; 443. Annular plate; 444. Spiral groove; 5. Connecting assembly; 51. Central gear; 52. Gear ring; 521. Connecting rod; 53. Transmission gear; 54. Mounting bracket; 541. Mounting rod. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Please see Figures 1 to 6 This invention provides a carbon-silicon anode material slurry preparation apparatus and preparation method, the technical solution of which is as follows: For details, please refer to Figure 1 , Figure 2 and Figure 3 A silicon-carbon anode material slurry preparation apparatus includes a mixing tank 1, with a discharge pipe 11 at the bottom of the mixing tank 1. A tank cover 2 is provided on the mixing tank 1, and a negative pressure suction pipe 21 and a feeding port 22 are provided on the tank cover 2.

[0032] The negative pressure extraction pipe 21 is used to extract excess air above the liquid surface in the mixing tank 1 to form a negative pressure, thereby accelerating the discharge of tiny air bubbles in the slurry.

[0033] The feed port 22 is used to add the preparation material into the mixing tank 1, and the prepared slurry can be discharged from the discharge pipe 11 at the bottom of the mixing tank 1. The bottom of the mixing tank 1 is arc-shaped so that the slurry can gather towards the central axis of the mixing tank 1.

[0034] The silicon carbide anode material slurry preparation device also includes a motor 3, a stirring assembly 4, and a connecting assembly 5. The motor 3 is mounted on the tank cover 2, and the stirring assembly 4 is located inside the stirring tank 1 and connected to the motor 3.

[0035] Optionally, the stirring assembly 4 includes a first spiral blade 41 and a second spiral blade 42, which are connected by a connecting assembly 5.

[0036] As one embodiment of the present invention, refer to Figure 2 , Figure 3 , Figure 4 and Figure 5 The stirring assembly 4 also includes a rotating rod 43 and a guide tube 44.

[0037] Optionally, the rotating rod 43 is located at the output end of the motor 3 and extends through the tank cover 2 into the interior of the mixing tank 1. The first spiral blade 41 is fixedly sleeved on the rotating rod 43, and the second spiral blade 42 is coaxial with the first spiral blade 41 and slides against the inner wall of the mixing tank 1.

[0038] Optionally, the guide tube 44 is coaxially sleeved with the first spiral blade 41, the second spiral blade 42 is fixedly sleeved with the outer wall of the guide tube 44 and has the same spiral direction as the first spiral blade 41, and the upper end of the first spiral blade 41 is higher than the liquid level.

[0039] Optionally, the connecting assembly 5 includes a central gear 51, a gear ring 52, a transmission gear 53, and a mounting bracket 54.

[0040] Optionally, the central gear 51 is fixedly sleeved on the rotating rod 43, the gear ring 52 is sleeved with the central gear 51, and the transmission gear 53 is meshed between the central gear 51 and the gear ring 52. The mounting bracket 54 is fixedly installed at the bottom of the can cover 2 and is rotatably sleeved with the gear ring 52 through a sealed bearing.

[0041] Optionally, the mounting bracket 54 is provided with a mounting rod 541, which is rotatably sleeved with the transmission gear 53. The side wall of the gear ring 52 has a circumferential array of multiple connecting rods 521, which are fixedly connected to the spiral blade 42.

[0042] Under the above-mentioned conditions, when the motor 3 is powered on, it will directly drive the connected rotating rod 43 to rotate.

[0043] On the one hand, since the spiral blade 41 is coaxially fixed on the rotating rod 43, the rotating rod 43 can drive the spiral blade 41 to rotate synchronously when it rotates. Furthermore, during the rotation of the spiral blade 41, the slurry at the bottom of the mixing tank 1 can be conveyed upward to the liquid surface through the guide pipe 44 by the limiting effect of the guide pipe 44.

[0044] On the other hand, since a central gear 51 is coaxially fixedly sleeved on the rotating rod 43, and the side of the central gear 51 meshes with the gear ring 52 through the transmission gear 53, during the synchronous rotation of the central gear 51 following the drive rod, the gear ring 52 will rotate in the opposite direction and at a low speed under the action of meshing transmission. Furthermore, since the second spiral blade 42 is located below the liquid surface and is fixedly connected to the gear ring 52 and the guide tube 44 through the connecting rod 521, the second spiral blade 42 can rotate in the opposite direction and at a low speed along with the gear ring 52. That is, the first spiral blade 41 and the second spiral blade 42 rotate in opposite directions, thus conveying the slurry below the liquid surface downwards to the bottom of the mixing tank 1 during the rotation of the second spiral blade 42. This allows the motor 3 to continuously circulate and convey the slurry in the mixing tank 1 using the first spiral blade 41 and the second spiral blade 42 when it is working.

[0045] As one embodiment of the present invention, refer to Figure 6 The guide tube 44 includes a vertical tube 441 and a tapered tube 442 that are fixedly connected from top to bottom.

[0046] Optionally, the vertical pipe 441 is coaxial with and movably connected to the spiral blade 41. Optionally, the upper port diameter of the tapered pipe 442 is smaller than the lower port diameter, and the upper end of the spiral blade 41 is higher than the upper end of the vertical pipe 441. The upper end of the vertical pipe 441 is positioned above the liquid surface.

[0047] The inner wall of the tapered tube 442 has a circumferential array of multiple spiral grooves 444, and the spiral direction of the spiral grooves 444 is opposite to the spiral direction of the spiral blade 41.

[0048] Under the aforementioned conditions, on the one hand, the vertical pipe 441 and the conical pipe 442 can rotate synchronously in opposite directions with the second spiral blade 42, allowing the first spiral blade 41 to accelerate the upward conveying of the slurry inside the vertical pipe 441 during rotation. Compared to the conveying method in a screw conveyor where the internal spiral conveying blades rotate while the external sleeve remains stationary, this method can provide higher shear force to the slurry during conveying, thereby achieving a more effective shearing and breaking effect on the agglomerates. Furthermore, after the slurry flows out from the upper end of the vertical pipe 441, it can separate from the liquid surface, preventing the tiny air bubbles carried in the slurry from immediately flowing back to the liquid surface.

[0049] On the other hand, the tapered tube 442 can increase the flow range of the lower end of the vertical tube 441. During the rotation process, in conjunction with the function of the spiral groove 444, the slurry entering the vertical tube 441 through the lower end of the tapered tube 442 will generate a swirling flow in advance, thereby ensuring the stable conveying of the slurry from bottom to top.

[0050] The lead of the spiral groove 444 is greater than that of the spiral blade 41, which reduces the axial resistance to the upward flow of the slurry as it rotates with the tapered tube 442, ensuring that the slurry can smoothly enter the vertical tube 441 with the lifting force of the spiral blade 41.

[0051] As one embodiment of the present invention, refer to Figure 5 and Figure 6 The upper outer wall of the vertical pipe 441 is fixedly fitted with a funnel-shaped annular plate 443, which is located above the liquid surface and the diameter of the two ends decreases from top to bottom.

[0052] Optionally, the second spiral blade 42 is disposed below the annular plate 443 and below the liquid surface inside the mixing tank 1.

[0053] Under the aforementioned conditions, the slurry flowing from the upper end of the vertical pipe 441 falls onto the upper surface of the annular plate 443 and gathers towards its center. Since the annular plate 443 is fixedly fitted onto the vertical pipe 441, and the vertical pipe 441 is fixedly connected to the spiral blade 42, the spiral blade 42, during rotation, drives the annular plate 443 to rotate and generates centrifugal force. This causes the slurry on the upper surface of the annular plate 443 to move towards the edge of the annular plate 443 in a flat, slow-flowing manner under the action of centrifugal force, until it crosses the edge of the annular plate 443 and falls back to the liquid surface. This allows the tiny air bubbles in the slurry on the upper surface of the annular plate 443 to fully contact the air, and then, under the action of the negative pressure extraction pipe 21 (which can be connected to an external negative pressure pump, and the negative pressure pump, when working, creates a negative pressure inside the negative pressure extraction pipe 21, thereby extracting the air from inside the mixing tank 1), it is discharged to the outside of the mixing tank 1. During its rotation, the spiral blade 42 can transport the slurry carrying tiny air bubbles from below the liquid surface to the bottom of the mixing tank 1, so as to facilitate the circulation of the slurry.

[0054] A method for preparing a silicon-carbon anode material slurry includes the following steps: S1. Add the preparation material into the mixing tank 1 through the feeding port 22 and start the motor 3; S2, Motor 3 drives spiral blade 1 41 and spiral blade 2 42 to rotate. Spiral blade 2 42 transports the slurry carrying tiny air bubbles below the liquid surface to the bottom of the mixing tank 1. Spiral blade 1 41 transports the slurry that has gathered at the bottom of the mixing tank 1 and carries tiny air bubbles upward to the top of the liquid surface. S3. The slurry, which is conveyed to the liquid surface and carries tiny air bubbles, falls onto the surface of the annular plate 443 and, after being spread out and degassed by the rotation of the annular plate 443, returns to the slurry below the annular plate 443.

[0055] Working principle: In use, firstly, silicon carbide anode material is added to the mixing tank 1 through the feeding port 22, and the motor 3 is started. The motor 3 drives the rotating rod 43 to drive the spiral blade 41 to rotate synchronously in the forward high speed. At this time, the central gear 51 fixed on the rotating rod 43 drives the gear ring 52 to rotate through the transmission gear 53 set on the mounting bracket 54, and then drives the spiral blade 42 to rotate in the reverse low speed through the connecting rod 521. During this process, the conical tube 442 uses the spiral grooves 444 of its inner wall to physically impede and guide the slurry in the reverse direction. Together with the high-speed rotating spiral blade 41, it forms an extremely high-intensity shear field inside the guide tube 44, which gathers the slurry at the bottom corner of the mixing tank 1 towards the center and breaks up the micron-sized agglomerates. Subsequently, the uniformly broken slurry, carrying deep microbubbles, is transported upwards along an independent ascending channel formed by vertical pipes 441 to above the liquid surface under the action of the first spiral blade 41, and flows out from the upper end of the vertical pipe 441 onto the upper surface of the funnel-shaped annular plate 443. Next, the annular plate 443 rotates synchronously with the second spiral blade 42, generating centrifugal force that forces the slurry to spread into a thin film on the surface of the annular plate 443 in a flat, slow-flowing manner. This drastically reduces the matrix resistance experienced by the microbubbles in the slurry, allowing them to directly contact the air. Real-time degassing and discharge of the bubbles are achieved in the negative pressure environment created by the negative pressure extraction pipe 21. Finally, the degassed slurry falls back to the liquid surface from the edge of the annular plate 443, and is transported downwards to the bottom by the second low-speed reverse spiral blade 42, which is attached to the inner wall of the mixing tank 1. This, combined with the upward transport along the central axis of the first spiral blade 41, forms a strong axial circulating flow field. Through continuous circulating stirring and real-time thin-film degassing (in order to achieve efficient degassing, the edge linear velocity of the annular plate 443 is controlled between 2m / s and 5m / s, and the angle between the trumpet-shaped inclined surface of the annular plate 443 and the horizontal plane is 20°–40°, under which the high-viscosity slurry can form a film with a thickness of less than 1mm), a high-quality carbon silicon anode material slurry with no bubble residue and uniform fineness is finally prepared and discharged from the discharge pipe 11 at the bottom of the stirring tank 1.

[0056] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for preparing silicon carbide anode material slurry, characterized in that: The system includes a mixing tank (1), which is provided with a tank cover (2), a motor (3), a stirring assembly (4), and a connecting assembly (5). The motor (3) is located on the tank cover (2), and the stirring assembly (4) is located inside the mixing tank (1) and connected to the motor (3). The stirring assembly (4) includes a first spiral blade (41) and a second spiral blade (42). The first spiral blade (41) and the second spiral blade (42) are connected by the connecting assembly (5). When the motor (3) is powered on, it drives the first spiral blade (41) to rotate at high speed in the forward direction and transports the slurry at the center of the mixing tank (1) from bottom to top to above the liquid surface. When the first spiral blade (41) rotates at high speed in the forward direction, it drives the second spiral blade (42) to rotate at low speed in the reverse direction through the connecting assembly (5) and transports the slurry near the inner wall of the mixing tank (1) from top to bottom below the liquid surface.

2. The apparatus for preparing silicon carbide anode material slurry according to claim 1, characterized in that: The stirring assembly (4) also includes a rotating rod (43) and a guide tube (44). The rotating rod (43) is located at the output end of the motor (3) and passes through the tank cover (2) to the inside of the stirring tank (1). The first spiral blade (41) is fixedly sleeved on the rotating rod (43). The second spiral blade (42) is coaxial with the first spiral blade (41) and slides against the inner wall of the stirring tank (1). The guide tube (44) is coaxially sleeved with the first spiral blade (41). The second spiral blade (42) is fixedly sleeved with the outer wall of the guide tube (44) and has the same spiral direction as the first spiral blade (41).

3. The apparatus for preparing silicon carbide anode material slurry according to claim 2, characterized in that: The connecting assembly (5) includes a central gear (51), a gear ring (52), a transmission gear (53), and a mounting bracket (54). The central gear (51) is fixedly sleeved on the rotating rod (43). The gear ring (52) is sleeved with the central gear (51). The transmission gear (53) is meshed between the central gear (51) and the gear ring (52). The mounting bracket (54) is fixedly installed at the bottom of the can cover (2) and rotatedly sleeved with the gear ring (52). The mounting bracket (54) is provided with a mounting rod (541). The mounting rod (541) is rotatedly sleeved with the transmission gear (53). The side wall of the gear ring (52) has a circumferential array of multiple connecting rods (521). The connecting rods (521) are fixedly connected to the spiral blade (42).

4. The apparatus for preparing silicon carbide anode material slurry according to claim 2, characterized in that: The guide tube (44) includes a vertical tube (441) and a tapered tube (442) fixedly connected from top to bottom. The upper port diameter of the tapered tube (442) is smaller than the lower port diameter. The upper end of the spiral blade (41) is higher than the upper end of the vertical tube (441). The upper end of the vertical tube (441) is located above the liquid surface.

5. The apparatus for preparing silicon carbide anode material slurry according to claim 4, characterized in that: The upper outer wall of the vertical tube (441) is fixedly fitted with a funnel-shaped annular plate (443), which is located above the liquid surface and the diameter of the two ends decreases from top to bottom.

6. The apparatus for preparing silicon carbide anode material slurry according to claim 4, characterized in that: The inner wall of the tapered tube (442) has a circumferential array of multiple spiral grooves (444), the spiral direction of which is opposite to that of the spiral blade (41).

7. The apparatus for preparing silicon carbide anode material slurry according to claim 5, characterized in that: The second spiral blade (42) is located below the annular plate (443) and below the liquid surface inside the mixing tank (1).

8. A method for preparing a silicon-carbon anode material slurry, characterized in that, The preparation of silicon carbide anode material slurry using the apparatus described in any one of claims 1-7 includes the following steps: S1. Add the preparation material into the mixing tank (1) through the feeding port (22) and start the motor (3); S2. The motor (3) drives the first spiral blade (41) and the second spiral blade (42) to rotate. The second spiral blade (42) transports the slurry carrying tiny bubbles below the liquid surface to the bottom of the mixing tank (1), and the first spiral blade (41) transports the slurry that has gathered at the bottom of the mixing tank (1) and carries tiny bubbles upward to the top of the liquid surface. S3. The slurry, which is conveyed to the liquid surface and carries tiny air bubbles, falls onto the surface of the annular plate (443) and spreads out to release air as the annular plate (443) rotates, returning to the slurry below the annular plate (443).

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