Mixing device and preparation method of ternary lithium ion battery negative electrode composite material

Abstract

The invention relates to the technical field of lithium batteries, in particular to a mixing device and a preparation method of a ternary lithium ion battery negative electrode composite material, the mixing device comprises a mixing tank, the upper end of the mixing tank is provided with a tank cover, the lower end of the mixing tank is conical and has a small lower part and a large upper part, and the lower end of the mixing tank is fixedly connected with a discharge pipe; a feeding pipe is fixedly connected to one side of the middle of the upper end of the tank cover, pipe clamp valves controlled by an external circuit are arranged at the joint of a discharging pipe and the mixing tank and on the feeding pipe, a supporting frame is fixedly connected to the middle of the upper end face of the tank cover, and a servo motor is arranged in the middle of the upper end of the supporting frame; a mixing assembly is arranged in the mixing tank and is driven by a servo motor. Compared with the prior art, the problems of poor mixing uniformity, poor particle fineness control and low discharging efficiency in the mixing process of the ternary lithium ion battery negative electrode composite material in the prior art are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium batteries, and in particular to a mixing device and a preparation method of a ternary lithium-ion battery negative electrode composite material. Background Art

[0002] Amid the rapid development of the new energy industry, ternary lithium-ion batteries (NMC) are widely used in power batteries and energy storage systems due to their high energy density, long cycle life, and excellent safety performance. The physical form (such as particle size distribution and particle morphology) of the negative electrode composite material, a core functional material, significantly influences the battery's capacity, rate capability, and cycle stability. To improve the overall performance of the negative electrode material, carbon-based materials of varying particle sizes and forms (such as graphite, soft carbon, and hard carbon) are typically mixed with conductive additives and binders in specific ratios. Larger particles are then moderately ground to a particle size that better matches the electrochemical performance requirements.

[0003] In the prior art, a Chinese patent document with publication number CN114392688A proposes an auxiliary material premixing device for preparing lithium battery materials, comprising a support structure, a cylinder, and a stirring assembly. The bottom of the support structure is fixedly connected to a support leg, and a through hole is opened in the center of the support structure and passes through the upper and lower parts. The cylinder is fixedly connected to the through hole in the center of the support structure, and the cylinder is divided into an upper and lower part. The bottom of the cylinder is connected to a discharge port with a valve, and the top of the cylinder is fixedly connected to a plurality of independent auxiliary material tanks. At the same time, the stirring assembly is rotatably connected to the inside of the cylinder. Although this application solves the problems of a long time required to disperse the auxiliary material and mix it with the main material and the single existing mixing method with poor mixing effect, this technology is consistent with the traditional method in that the mixing device is mostly a general structure and lacks a special design for the negative electrode composite material of ternary lithium-ion batteries. However, most existing mixing devices are of general-purpose structures, and their original design was not tailored to the process requirements of ternary lithium-ion battery anode composite materials, resulting in multiple technical limitations in practical applications: 1. Particle deposition problem is prominent and mixing uniformity is poor: The negative electrode composite materials of ternary lithium-ion batteries are usually composed of components with different densities and particle sizes, including spherical graphite, natural flake graphite, carbon black, soft carbon particles and binders. These materials have obvious chromatographic distribution tendencies during the stirring process, especially flake graphite particles with larger particle size or density, which are easily deposited to the bottom of the tank due to gravity during the stirring process and are difficult to be disturbed and flipped up again by the stirring blades, resulting in insufficient mixing of the upper and lower components, which in turn affects the consistency of the subsequent coating slurry and the uniformity of the electrode thickness.

[0004] 2. Limited disturbance capability and poor structural adaptability: Conventional stirring structures mostly use simple paddles or straight rod rotation, which cannot effectively turn over the settled particles. In particular, under high viscosity conditions, the stirring shear force is insufficient, making it difficult to transport the bottom sediment materials to the upper part of the tank for remixing, causing some areas to be in a "dead zone" state. In addition, this type of structure has a fixed stirring path and a single disturbance mode, which is not suitable for the physical property requirements of "interlayer crushing and uniform mixing" required in battery negative electrode slurry.

[0005] 3. Rough grinding control and easy damage to raw material structure: In order to meet the slurry dispersion requirements, some large particles in the negative electrode material that are easy to agglomerate, such as agglomerated soft carbon, need to be moderately ground during the mixing process. However, most existing devices do not have integrated grinding functions, or use high-intensity mechanical shearing methods, which can easily cause mechanical damage to materials with crystalline structures such as soft carbon and natural graphite, resulting in flake peeling and increased specific surface area, thereby exacerbating interfacial side reactions and reducing the battery's initial coulombic efficiency and cycle life. Excessive grinding may also destroy the conductive network distribution, resulting in uneven conductivity of the slurry, posing a potential risk to battery consistency.

[0006] 4. Low discharge efficiency affects slurry quality: After mixing, the negative electrode composite material for ternary lithium-ion batteries forms a colloidal slurry with high viscosity, making it difficult to drain quickly via traditional gravity discharge methods. Some of the viscous material remains at the bottom of the tank or at the discharge port, requiring manual intervention. This not only affects efficiency but also easily leads to material ratio deviations and cross-contamination, which in turn affects the performance consistency of the entire battery batch.

[0007] Furthermore, we disclose a mixing device and preparation method for a ternary lithium-ion battery negative electrode composite material to address the problems of poor mixing uniformity, poor particle fineness control and low discharge efficiency in the mixing process of the ternary lithium-ion battery negative electrode composite material in the prior art. Summary of the Invention

[0008] In view of this, the purpose of the present invention is to propose a mixing device and preparation method for a ternary lithium-ion battery negative electrode composite material, so as to solve the problems of poor mixing uniformity, poor particle fineness control and low discharge efficiency in the mixing process of the prior art ternary lithium-ion battery negative electrode composite material.

[0009] Based on the above purpose, the present invention provides a mixing device for a ternary lithium-ion battery negative electrode composite material, comprising a mixing tank, wherein a tank cover is provided at the upper end of the mixing tank, the lower end of the mixing tank is conical and smaller at the bottom and larger at the top, a discharge pipe is fixedly connected to the lower end of the mixing tank, a feed pipe is fixedly connected to one side of the middle of the upper end of the tank cover, a pipe clamp valve controlled by an external circuit is provided at the connection between the discharge pipe and the mixing tank and on the feed pipe, a support frame is fixedly connected to the middle of the upper end surface of the tank cover, and a servo motor is provided at the middle of the upper end of the support frame; The interior of the mixing tank is provided with a mixing assembly, which is driven by a servo motor. The mixing assembly is used to fully mix the graphite, soft carbon, conductive agent, binder, etc. in the negative electrode composite material of the ternary lithium-ion battery, and flip the large particle components deposited at the bottom to the upper end. The mixing assembly includes a connecting plate rotatably connected to the upper end of the mixing tank, and both sides of the lower end of the connecting plate are engaged and rotatably connected with connecting rods, and the outer walls of the two connecting rods are engaged and rotatably connected with a plurality of disturbance ratchet rods, and the upper end of the outer wall of the connecting rod is fixedly connected with a spur gear. The upper end of the inner wall of the mixing tank is located at the height of the spur gear and is evenly spaced and fixedly connected to a plurality of tooth blocks corresponding to the spur gear, the spur gear is meshed with the tooth blocks, the mixing assembly further comprises a spiral rotating rod fixedly connected to the middle part of the lower end surface of the connecting plate, the lower end of the interior of the mixing tank is evenly spaced and fixedly connected to a plurality of fixed rods, the upper ends of the plurality of fixed rods are fixedly connected to a liquid storage cylinder, the liquid storage cylinder is sleeved on the outside of the spiral rotating rod and the upper end of the liquid storage cylinder is outwardly expanded, the output end of the servo motor passes through the tank cover and extends into the interior of the mixing tank and is fixedly connected to the middle part of the connecting plate; A grinding assembly is provided at the lower end of the inner middle portion of the mixing tank, and the grinding assembly is used to crush the soft carbon, natural graphite, etc. that are easy to agglomerate in the negative electrode composite material of the ternary lithium-ion battery, and to achieve particle size control without destroying its crystal structure. The grinding assembly includes a mounting ring that is sleeved on the outside of the liquid storage cylinder, and the inner wall of the mounting ring is fixedly connected with a plurality of connecting rods at even intervals, and the end of the connecting rod away from the mounting ring is fixedly connected to the liquid storage cylinder, and the upper end of the mounting ring is fixedly connected with a plurality of pressure springs at even intervals, and the upper ends of the plurality of pressure springs are fixedly connected with a lower grinding sheet, and the upper end surface of the lower grinding sheet is arc-shaped. The upper end of the lower grinding sheet is provided with an upper grinding sheet, the lower end surface of the upper grinding sheet is arc-shaped and adapted to the upper end surface of the lower grinding sheet, the upper end surface of the lower grinding sheet and the lower end surface of the upper grinding sheet are both frosted surfaces, the upper end of the upper grinding sheet is evenly spaced and fixedly connected with a liquid inlet pipe, the lower end of the liquid inlet pipe passes through the upper grinding sheet and the upper end is inclined to one side, the inner sides of both ends of the upper end surface of the upper grinding sheet are fixedly connected with linkage rods, the upper ends of the two linkage rods are fixedly connected to the connecting plate, the inner wall of the upper grinding sheet is evenly spaced and fixedly connected with a plurality of clamping plates, and the upper grinding sheet is rotatably connected to the liquid storage cylinder through the clamping plates; A discharge assembly is provided on one side of the mixing tank, and the discharge assembly is used to assist the discharge of the ternary lithium-ion battery negative electrode composite material inside the mixing tank to increase the discharge speed; the discharge assembly includes a piston cylinder fixedly connected to one side of the mixing tank, a piston plate is slidably connected to the inside of the piston cylinder, both sides of the lower end surface of the piston plate are fixedly connected to return springs, the lower ends of the two return springs are fixedly connected to the inner bottom surface of the piston cylinder, the middle part of the upper end surface of the piston plate is fixedly connected to a first steel wire rope, the middle side of the upper end surface of the piston plate is fixedly connected to a push rod, the upper end of the push rod is fixedly connected to an anti-slip frame, and the inner corners of the upper end of the anti-slip frame are provided with round The cam is fixedly provided with an air pipe at the middle of the lower end surface of the piston cylinder, and the lower end of the air pipe is fixedly connected to the discharge pipe. A rotating wheel is provided at the lower end of the internal part of the discharge pipe, and a driving rod is fixedly connected at the axis of the rotating wheel. One end of the driving rod passes through the discharge pipe and extends into the interior of the air pipe and is fixedly connected to a fan blade. A plurality of vent holes are evenly spaced apart on the outer wall of the lower end of the air pipe. The discharge assembly also includes a mounting bracket fixedly connected to one side of the upper end of the tank cover, and one side of the upper end of the mounting bracket is rotatably connected to a winding roller. The upper end of the first steel wire rope is wound around the winding roller and the tail end is fixedly connected to the winding roller. The middle of the winding roller is fixedly connected to a rotating shaft, and one end of the rotating shaft passes through The cam is fixedly provided with a toothed connecting strip which is fixed to the toothed connecting strip on the toothed connecting strip and is fixedly connected to the toothed connecting strip on the toothed connecting strip. The outer walls of the motor output ends are fixedly connected to pulleys, and the outer sleeves of the two pulleys are provided with belts. The upper end of the pulley on one side of the support seat is fixedly connected to the active bevel gear. When the interference spring is in an uncompressed state, the driven bevel gear is meshed with the active bevel gear, and the inner side of the piston plate is fixedly connected to a connecting spring. One end of the connecting spring is fixedly connected to a limiting rod. A limiting hole is provided on the upper end of the outer wall of the piston cylinder, and the corners of the outer walls of the limiting hole and the limiting rod are both provided with rounded corners. When the piston plate is located at the uppermost end of the piston cylinder, the limiting rod is located inside the limiting hole to limit the piston plate. In addition, the anti-detachment frame will push the second steel wire rope to bend.

[0010] A method for preparing a ternary lithium-ion battery negative electrode composite material, using the mixing device of the ternary lithium-ion battery negative electrode composite material, comprises the following steps: S1: Check whether the mixing tank, tank cover, feed pipe, and discharge pipe are installed properly to ensure there is no leakage, connect the power supply, check whether the servo motor and pipe clamp valve are working properly, prepare the ternary lithium-ion battery negative electrode composite material to be mixed, and ensure that the material is free of impurities; S2: Add the material to be mixed into the mixing tank through the feed pipe, close the tank lid to ensure a good seal, start the servo motor to drive the mixing assembly to work, and the connecting plate, connecting rod, disturbance ratchet rod, and spiral rotating rod in the mixing assembly begin to rotate and flip, fully stirring the material and flipping the material from the bottom of the mixing tank to the top. At the same time, the upper grinding plate, lower grinding plate, and pressure spring in the grinding assembly start to work, grinding the large particles in the material into small particles; S3: When the mixing and grinding reaches the predetermined time or effect, turn off the servo motor, stop the mixing and grinding work, ensure that the clamp valve on the discharge pipe is in the closed state, prepare for discharge, and check whether the piston plate, air pipe, fan blade, runner, winding roller, first wire rope, driven bevel gear, driving bevel gear, limit rod, etc. in the discharge assembly are in normal working condition; S4: Open the clamp valve on the discharge pipe and press the limit rod to make the piston plate move downward rapidly under the action of the return spring, compressing the air in the piston cylinder. The gas quickly enters the discharge pipe through the air pipe, blowing the fan blades to rotate, generating suction, and assisting the rapid discharge of materials.

[0011] Compared with the prior art, the present invention has at least the following beneficial effects: 1. A mixing assembly is provided. The mixing assembly is equipped with a multi-stage linkage structure including a connecting plate, a connecting rod, a disturbance ratchet rod and a spiral rotating rod. It can realize a compound motion path under the drive of a servo motor, so that the raw materials (such as flake graphite, soft carbon particles, conductive carbon black, etc.) at different heights and densities in the mixing tank can be fully disturbed and turned under a high viscosity system, which significantly improves the mixing uniformity. In particular, the disturbance ratchet rod and the inner wall tooth block form an interlocking friction structure, which can effectively overcome the "dead zone" where large particles are deposited to the bottom of the tank due to gravity, realize the continuous circulation of the upper and lower layers of materials, avoid the stratification of components, and effectively ensure the stability and consistency of the negative electrode slurry.

[0012] 2. A grinding assembly is provided, which adopts an upper and lower paired arc-shaped grinding plate structure, and is equipped with a pressure spring to form an elastically loaded grinding area. It can not only achieve moderate deagglomeration of large agglomerated particles (such as soft carbon agglomerates and graphite sheets) in the negative electrode composite material of the ternary lithium-ion battery, but also avoid the destruction of the layer structure caused by excessive grinding through flexible shearing action. A spiral grinding path is formed by rotating in conjunction with the mixing assembly, and an inclined liquid inlet pipe is introduced to realize the introduction of lubricating medium, further reducing frictional heat, improving grinding efficiency, while ensuring that the original crystal structure of the material is not destroyed, and enhancing its electrochemical performance and cycle stability.

[0013] 3. A discharge assembly is provided. Through the combined action of the piston plate, spring energy storage mechanism, air pipe and discharge pipe, the problem of discharging high-viscosity negative electrode slurry after mixing is solved. The piston plate is preloaded to the upper end by the winding roller to form an energy storage state. After the limit is released, the gas can be instantly compressed to form a pneumatic discharge force. At the same time, the rotating fan blades and the runner form a negative pressure suction in the discharge channel, so that the slurry is discharged from the tank quickly and evenly, significantly improving the discharge speed, reducing the residual material, effectively preventing the component ratio deviation and cross contamination, and ensuring the accuracy and stability of the battery slurry ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 Schematic diagram of the internal three-dimensional structure of the present invention; Figure 3 It is a schematic diagram of a partial three-dimensional structure of the present invention; Figure 4 This is a schematic diagram of the three-dimensional structure of the grinding assembly of the present invention; Figure 5 This is a schematic diagram of the internal three-dimensional structure of the grinding assembly of the present invention; Figure 6 This is a schematic diagram of a partial three-dimensional structure of a liquid discharge assembly according to the present invention; Figure 7 This is a schematic diagram of the internal three-dimensional structure of the mounting frame of the present invention; Figure 8 This is a schematic diagram of the three-dimensional structure of the piston plate of the present invention; Figure 9 For the present invention Figure 2 Enlarged view of point A in the middle; Figure 10 It is a schematic diagram of the three-dimensional structure of the runner of the present invention.

[0016] The following are marked in the figure: 1. Mixing tank; 2. Discharge pipe; 3. Pinch valve; 4. Tank cover; 5. Servo motor; 6. Piston cylinder; 7. Air pipe; 8. First wire rope; 9. Mounting frame; 10. Winding roller; 11. Screw rod; 12. Connecting rod; 13. Support frame; 14. Liquid storage cylinder; 15. Upper grinding disc; 16. Rotating wheel; 17. Return spring; 18. Piston plate; 19. Ejector rod; 20. Belt; 21. Connecting plate; 22. Spur gear; 23. Disturbance ratchet rod; 24. Linking rod; 25 , liquid inlet pipe; 26, fixing rod; 27, lower grinding plate; 28, clamping plate; 29, connecting rod; 30, mounting ring; 31, pressure spring; 32, driven bevel gear; 33, driving bevel gear; 34, pulley; 35, support seat; 36, limiting hole; 37, resistance spring; 38, rotating plate; 39, spline; 40, second steel wire rope; 41, rotating shaft; 42, anti-slip frame; 43, connecting spring; 44, limiting rod; 45, vent; 46, driving rod; 47, fan blade. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below with reference to specific embodiments. The mixing device described in this embodiment specifically addresses technical challenges encountered in the industrial production of ternary lithium-ion battery anode composite materials, such as poor mixing uniformity, easy deposition of large particles, poor particle grinding control, and low discharge efficiency. Through sophisticated structural design and multi-stage linkage, it achieves full-process adaptation and optimization.

[0018] It should be noted that, unless otherwise defined, the technical or scientific terms used in the present invention should have the usual meanings understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0019] like Figures 1 to 10As shown, a mixing device for a ternary lithium-ion battery negative electrode composite material comprises a mixing tank 1, a tank cover 4 is provided at the upper end of the mixing tank 1, the lower end of the mixing tank 1 is tapered and smaller at the bottom and larger at the top, a discharge pipe 2 is fixedly connected to the lower end of the mixing tank 1, a feed pipe is fixedly connected to one side of the middle of the upper end of the tank cover 4, a pipe clamp valve 3 controlled by an external circuit is provided at the connection between the discharge pipe 2 and the mixing tank 1 and on the feed pipe, a support frame 13 is fixedly connected to the middle of the upper end surface of the tank cover 4, a servo motor 5 is provided in the middle of the upper end of the support frame 13, and the interior of the mixing tank 1 is provided with a plurality of servo motors. A mixing assembly is provided, which is driven by a servo motor 5. The mixing assembly is used to mix the various materials inside the mixing tank 1 and can flip the materials at the bottom to the upper end of the mixing tank 1. A grinding assembly is provided at the lower end of the middle part of the mixing tank 1. The grinding assembly is used to crush large particles in the materials inside the mixing tank 1 into small particles to improve the mixing effect of the composite material. A discharge assembly is provided on one side of the mixing tank 1. The discharge assembly is used to assist in the discharge of the materials inside the mixing tank 1 to increase the discharge speed. The present invention provides a mixing device for a ternary lithium-ion battery negative electrode composite material, comprising a mixing tank 1, a tank cover 4, a feed pipe, a discharge pipe 2, a pipe clamp valve 3, a support frame 13, a servo motor 5, a mixing assembly, a grinding assembly and a discharge assembly. The components are reasonably coordinated through a mechanical structure to complete the pre-dispersion, tumbling, grinding and efficient discharge process of raw materials such as graphite, soft carbon and carbon black in the ternary negative electrode composite material.

[0020] Further, such as Figures 1 to 3 As shown, the mixing assembly includes a connecting plate 21 rotatably connected to the upper end of the interior of the mixing tank 1, and the lower end of the connecting plate 21 is engaged and rotatably connected to the connecting rod 12 on both sides, and the outer walls of the two connecting rods 12 are engaged and rotatably connected to multiple disturbance ratchet rods 23, and the upper end of the outer wall of the connecting rod 12 is fixedly connected to a spur gear 22, and the upper end of the inner wall of the mixing tank 1 is located at the position height of the spur gear 22 and is evenly spaced and fixedly connected to a plurality of tooth blocks corresponding to the spur gear 22, and the spur gear 22 is meshed with the tooth blocks. The mixing assembly also includes a spiral rotating rod 11 fixedly connected to the middle of the lower end surface of the connecting plate 21, and the lower end of the interior of the mixing tank 1 is evenly spaced and fixedly connected to a plurality of fixed rods 26, and the upper ends of the plurality of fixed rods 26 are fixedly connected to the liquid storage cylinder 14, which is sleeved on the outside of the spiral rotating rod 11 and the upper end of the liquid storage cylinder 14 is outwardly expanded. The output end of the servo motor 5 passes through the tank cover 4 and extends into the interior of the mixing tank 1 and is fixedly connected to the middle of the connecting plate 21; The mixing tank 1 has an overall conical structure with a small bottom and a large top, which is conducive to the sinking and concentration of materials and the disturbed flow at the top during the mixing and grinding process. The tank cover 4 is sealed to the upper end of the tank body through a flange to ensure the overall sealing of the device and prevent dust diffusion and component volatilization. A feed pipe is provided on the top of the tank cover 4, and a pipe clamp valve 3 controlled by an external circuit is provided at the pipe connection port to realize program control of the inlet and outlet paths; The mixing assembly is arranged in the upper area inside the mixing tank 1, including a connecting plate 21, a connecting rod 12, a disturbance ratchet rod 23, a spur gear 22, a tooth block, a spiral rotating rod 11 and a liquid storage cylinder 14. The output end of the servo motor 5 penetrates downward through the tank cover 4 and is connected to the middle of the connecting plate 21, driving the connecting plate 21 to rotate around the axis. Connecting rods 12 are connected on both sides of the connecting plate 21. A plurality of disturbance ratchet rods 23 are provided on the outer wall of the connecting rod 12, and cooperate with the tooth block structure provided above the inner wall of the mixing tank 1 to engage with the outer spur gear 22 of the connecting rod 12. During the rotation process, the connecting rod 12 rotates and revolves around the central axis, driving the disturbance ratchet rod 23 to perform three-dimensional disturbance on the surrounding materials. This mechanism is particularly suitable for the situation where flake graphite and conductive carbon black are unevenly distributed in high-viscosity media. The bottom deposited material can be forced to flip up to the upper part of the tank body to realize a fluid disturbance closed loop. In addition, a spiral rotating rod 11 is fixed in the middle of the mixing component, and a liquid storage cylinder 14 is installed on the outside of the mixing component. The upper end of the cylinder is expanded outward, which helps to guide the slurry to flow back upward and cooperate with the flipping effect. Multiple fixed rods 26 fix and support the liquid storage cylinder 14 structure, so that it is stably located in the central axis position of the tank bottom, and a natural sinking path is also formed during the mixing process, which is conducive to the re-aggregation of the raw materials into the grinding area.

[0021] Further, such as Figures 4 and 5 As shown, the grinding assembly includes a mounting ring 30 that is sleeved on the outside of the liquid storage cylinder 14. The inner wall of the mounting ring 30 is evenly spaced and fixedly connected to a plurality of connecting rods 29. The end of the connecting rod 29 away from the mounting ring 30 is fixedly connected to the liquid storage cylinder 14. The upper end of the mounting ring 30 is evenly spaced and fixedly connected to a plurality of pressure springs 31. The upper ends of the plurality of pressure springs 31 are fixedly connected to the lower grinding sheet 27. The upper end surface of the lower grinding sheet 27 is arc-shaped. The upper end of the lower grinding sheet 27 is provided with an upper grinding sheet 15. The lower end surface of the upper grinding sheet 15 is arc-shaped and is connected to the lower grinding sheet 27. The upper end surface of the lower grinding sheet 27 is adapted to the upper end surface of the upper grinding sheet 15, and the upper end surface of the lower grinding sheet 27 and the lower end surface of the upper grinding sheet 15 are both frosted surfaces. The upper end of the upper grinding sheet 15 is evenly spaced and fixedly connected to the liquid inlet pipe 25. The lower end of the liquid inlet pipe 25 passes through the upper grinding sheet 15 and the upper end is inclined to one side. The inner sides of both ends of the upper end surface of the upper grinding sheet 15 are fixedly connected to the linkage rod 24. The upper ends of the two linkage rods 24 are fixedly connected to the connecting plate 21. The inner wall of the upper grinding sheet 15 is evenly spaced and fixedly connected with a plurality of clamping plates 28. The upper grinding sheet 15 is engaged and rotatably connected with the liquid storage cylinder 14 through the clamping plates 28; A grinding assembly is provided at the bottom of the mixing tank 1, which is the key structure that distinguishes this device from traditional mixing equipment. The assembly consists of a mounting ring 30, a connecting rod 29, a pressure spring 31, a lower grinding plate 27, an upper grinding plate 15, a linkage rod 24, a clamping plate 28 and an inclined liquid inlet pipe 25. The upper grinding plate 15 is connected to the connecting plate 21 through the linkage rod 24, so that it rotates in coordination with the mixing assembly. The contact surfaces of the upper and lower grinding plates are designed to be an arc-shaped frosted structure, with the grinding area clamped in the middle. The pressure spring 31 provides downward elastic loading to achieve moderate pressure control. In the ternary negative electrode material, brittle particles such as soft carbon and natural graphite need to be broken up without destroying the crystal structure. The agglomeration phenomenon, the grinding assembly can provide a "buffer + rotational shear" effect to avoid the rigid shear of the traditional grinding method causing the particle size structure to collapse. The inclined liquid inlet pipe 25 passes through the upper grinding plate 15 to ensure that the liquid phase is introduced into the grinding area. The lubrication effect makes the material movement more uniform, reduces frictional heat and improves the grinding efficiency.

[0022] Further, such as Figures 6 to 10As shown, the discharge assembly includes a piston cylinder 6 fixedly connected to one side of the mixing tank 1, a piston plate 18 is slidably connected inside the piston cylinder 6, and both sides of the lower end surface of the piston plate 18 are fixedly connected with return springs 17, and the lower ends of the two return springs 17 are fixedly connected to the inner bottom surface of the piston cylinder 6, and the middle part of the upper end surface of the piston plate 18 is fixedly connected with a first steel wire rope 8, and one side of the middle part of the upper end surface of the piston plate 18 is fixedly connected with a push rod 19, and the upper end of the push rod 19 is fixedly connected with an anti-slip frame 42, and the inner corners of the upper end of the anti-slip frame 42 are all provided with rounded corners, and the middle part of the lower end surface of the piston cylinder 6 is fixedly connected with an air pipe 7, and the lower end of the air pipe 7 is fixedly connected to the discharge pipe 2, and the lower end of the inner part of the discharge pipe 2 is provided with a runner 1 6, a driving rod 46 is fixedly connected to the axis of the runner 16, one end of the driving rod 46 passes through the discharge pipe 2 and extends into the interior of the air pipe 7 and is fixedly connected to a fan blade 47, and a plurality of vent holes 45 are evenly spaced on the outer wall of the lower end of the air pipe 7. The discharge assembly also includes a mounting bracket 9 fixedly connected to one side of the upper end of the tank cover 4, and a winding roller 10 is rotatably connected to one side of the upper end of the mounting bracket 9. The upper end of the first steel wire rope 8 is wound around the winding roller 10 and the tail end is fixedly connected to the winding roller 10. A rotating shaft 41 is fixedly connected to the middle part of the winding roller 10, and one end of the rotating shaft 41 passes through the mounting bracket 9 and is evenly spaced and fixedly connected to a plurality of splines 39 on the outer wall. One end of the spline 39 is fixedly connected to the outer wall of the rotating shaft 41 and is slidably connected to the outer wall of the rotating shaft The driven bevel gear 32 is connected to the driven bevel gear 32, and the driven bevel gear 32 is engaged and rotatably connected to the rotating plate 38 on one side of the mounting frame 9. The rotating plate 38 is fixedly connected to a resistance spring 37 on one side of the end face of the rotating plate 38 close to the mounting frame 9. One end of the resistance spring 37 away from the rotating plate 38 is fixedly connected to the mounting frame 9. The end face of the rotating plate 38 close to the mounting frame 9 away from the resistance spring 37 is fixedly connected to a second steel wire rope 40. The end of the second steel wire rope 40 away from the rotating plate 38 is fixedly connected to the mounting frame 9. The discharge assembly also includes a support seat 35 fixedly connected to one side of the outer wall of the tank cover 4. The upper end of the support seat 35 and the outer wall of the output end of the servo motor 5 inside the support frame 13 are fixedly connected to the pulley 34. The two belt pulleys The outer sleeve of the wheel 34 is provided with a belt 20, and the upper end of the pulley 34 on one side of the support seat 35 is fixedly connected to the active bevel gear 33. When the interference spring 37 is in an uncompressed state, the driven bevel gear 32 is meshed and connected with the active bevel gear 33. The inner side of the piston plate 18 is fixedly connected to the connecting spring 43, and one end of the connecting spring 43 is fixedly connected to the limiting rod 44. A limiting hole 36 is provided on the upper end of the outer wall of the piston cylinder 6. The corners of the outer walls of the limiting hole 36 and the limiting rod 44 are both provided with rounded corners. When the piston plate 18 is located at the uppermost end of the piston cylinder 6, the limiting rod 44 is located inside the limiting hole 36 to limit the piston plate 18. In addition, the anti-slip frame 42 will push the second steel wire rope 40 to bend; In order to solve the problem of low slurry discharge efficiency, the device is provided with a discharge assembly. The piston cylinder 6 is fixed to one side of the mixing tank 1 through a bracket. A slidable piston plate 18 is provided inside. The lower end of the piston plate 18 is connected to two return springs 17 to achieve rapid gas compression in the compressed and released states. A first steel wire rope 8 is provided in the middle of the piston plate 18, and its upper end is wound around the winding roller 10 in the mounting frame 9 above the tank cover 4. The winding roller 10 is driven by the rotating shaft 41. The outer wall of the rotating shaft 41 is provided with a spline 39 and cooperates with the driven bevel gear 32 and the driving bevel gear 33 to form a linkage transmission mechanism. Structure, driven by the servo motor 5, the pulley 34 and the belt 20 are transmitted to the support seat 35, and then the winding roller 10 is linked to pull the piston plate 18 to the upper end ready state. After the mixing is completed, the operator presses the limit rod 44 to disengage the limit hole 36, and the piston plate 18 rushes down quickly under the action of the elastic force. The compressed air enters the discharge pipe 2 at a high speed through the air pipe 7 and the vent 45, driving the fan blade 47 to rotate and drive the runner 16 to rotate, thereby generating suction in the discharge pipe 2, prompting the high-viscosity slurry to be smoothly discharged to the external pipeline system, greatly improving the discharge speed and residual control.

[0023] In summary, the mixing device in this embodiment not only has traditional stirring and shearing functions, but also provides customized processing means for the raw material characteristics of the ternary lithium-ion battery negative electrode composite material through a special grinding component and auxiliary discharge system. Its disturbance, turning, grinding and discharge processes are completed in a coordinated manner, which significantly improves the consistency, stability and production line efficiency of the composite material, and provides stable material support for the large-scale manufacturing of high-energy-density batteries.

[0024] An embodiment of the present invention further provides a method for preparing a ternary lithium-ion battery negative electrode composite material, using the mixing device of the ternary lithium-ion battery negative electrode composite material, comprising the following steps: S1: Check whether the mixing tank 1, tank cover 4, feed pipe, and discharge pipe 2 are installed properly to ensure there is no leakage, connect the power supply, check whether the servo motor 5 and pipe clamp valve 3 are working properly, prepare the ternary lithium-ion battery negative electrode composite material to be mixed, and ensure that the material is free of impurities; S2: Add the material to be mixed into the mixing tank 1 through the feeding pipe, close the tank cover 4 to ensure a good seal, start the servo motor 5, drive the mixing assembly to work, and the connecting plate 21, connecting rod 12, disturbance ratchet rod 23, spiral rotating rod 11 and other parts of the mixing assembly begin to rotate and flip, fully stirring the material and flipping the material from the bottom of the mixing tank 1 to the top. At the same time, the upper grinding plate 15, lower grinding plate 27 and pressure spring 31 in the grinding assembly start to work, grinding large particles in the material into small particles; S3: When the mixing and grinding reaches the predetermined time or effect, the servo motor 5 is turned off, the mixing and grinding work is stopped, the clamp valve 3 on the discharge pipe 2 is ensured to be in the closed state, and the material is prepared for discharge. The piston plate 18, the air pipe 7, the fan blade 47, the runner 16, the winding roller 10, the first steel wire rope 8, the driven bevel gear 32, the driving bevel gear 33, and the limit rod 44 in the discharge assembly are checked to see if they are in normal working condition; S4: Open the pipe clamp valve 3 on the discharge pipe 2, press the limit rod 44, and make the piston plate 18 move downward rapidly under the action of the return spring 17, compressing the air in the piston cylinder 6. The gas quickly enters the discharge pipe 2 through the air pipe 7, blowing the fan blades 47 to rotate, generating suction, and assisting the rapid discharge of materials.

[0025] The preparation method of the above-mentioned ternary lithium-ion battery negative electrode composite material is compared with the existing technology: this method uses a specially designed mixing device, and realizes an efficient and uniform mixing and grinding process through precise step control. In step S1, the equipment is fully inspected to ensure no leakage and normal operation of the electrical equipment, providing a stable foundation for the subsequent mixing process. In step S2, the connecting plate 21, connecting rod 12, disturbance ratchet rod 23, spiral rotating rod 11 and other parts of the mixing component work together, not only to achieve full mixing of the material, but also to effectively flip the material from the bottom of the mixing tank 1 to the upper end, avoiding the deposition of large particles of material. At the same time, the upper grinding plate 15 and the lower grinding plate of the grinding component 27, the pressure spring 31, etc. are used to finely grind the large particles in the material, thereby improving the uniformity and performance of the composite material. In step S3, the discharge assembly is carefully inspected to ensure the smooth discharge process. Finally, in step S4, an innovative discharge mechanism is used to utilize the suction force generated by the gas flow to assist in the rapid discharge of the material, thereby greatly improving the discharge efficiency. Overall, the preparation method of the present invention realizes efficient and uniform mixing and grinding of the negative electrode composite material of the ternary lithium-ion battery, as well as a fast and reliable discharge process, through precise step control and special mixing device design, which provides a strong guarantee for obtaining high-quality composite materials and has significant advantages over the existing technical methods.

[0026] It should be understood by those skilled in the art that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention (including the claims) is limited to these examples. Within the scope of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0027] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A mixing device for a ternary lithium-ion battery negative electrode composite material, comprising a mixing tank (1), wherein the upper end of the mixing tank (1) is provided with a tank cover (4), characterized in that: The lower end of the mixing tank (1) is conical and smaller at the bottom and larger at the top. A discharge pipe (2) is fixedly connected to the lower end of the mixing tank (1). A feed pipe is fixedly connected to one side of the middle portion of the upper end of the tank cover (4). A pipe clamp valve (3) controlled by an external circuit is provided at the connection between the discharge pipe (2) and the mixing tank (1) and on the feed pipe. A support frame (13) is fixedly connected to the middle portion of the upper end surface of the tank cover (4). A servo motor (5) is provided at the middle portion of the upper end of the support frame (13). The mixing tank (1) is provided with a mixing assembly inside, and the mixing assembly is driven by a servo motor (5). The mixing assembly is used to fully mix graphite, soft carbon, conductive agent, binder, etc. in the negative electrode composite material of the ternary lithium ion battery, and flip the large particle components deposited at the bottom to the upper end. The mixing assembly includes a connecting plate (21) rotatably connected to the upper end of the mixing tank (1), and both sides of the lower end of the connecting plate (21) are engaged and rotatably connected with connecting rods (12). The outer walls of the two connecting rods (12) are engaged and rotatably connected with a plurality of disturbance ratchet rods (23). The upper end of the outer wall of the connecting rod (12) is fixedly connected to a spur gear (22). The upper end of the inner wall of the mixing tank (1) is located at a straight A plurality of tooth blocks corresponding to the spur gear (22) are fixedly connected at even intervals at the height of the gear (22), and the spur gear (22) is meshed with the tooth blocks. The mixing assembly further comprises a spiral rotating rod (11) fixedly connected to the middle of the lower end surface of the connecting plate (21). A plurality of fixed rods (26) are fixedly connected to the lower end of the interior of the mixing tank (1) at even intervals. The upper ends of the plurality of fixed rods (26) are fixedly connected to a liquid storage cylinder (14). The liquid storage cylinder (14) is sleeved on the outside of the spiral rotating rod (11) and the upper end of the liquid storage cylinder (14) is outwardly expanded. The output end of the servo motor (5) passes through the tank cover (4) and extends into the interior of the mixing tank (1) and is fixedly connected to the middle of the connecting plate (21). A grinding assembly is provided at the lower end of the inner middle portion of the mixing tank (1), and the grinding assembly is used to crush the soft carbon, natural graphite, etc. that are easy to agglomerate in the negative electrode composite material of the ternary lithium-ion battery, and to achieve particle size control without destroying its crystal structure. The grinding assembly includes a mounting ring (30) sleeved on the outside of the liquid storage cylinder (14), and the inner wall of the mounting ring (30) is evenly spaced and fixedly connected to a plurality of connecting rods (29), and one end of the connecting rod (29) away from the mounting ring (30) is fixedly connected to the liquid storage cylinder (14), and the upper end of the mounting ring (30) is evenly spaced and fixedly connected to a plurality of pressure springs (31), and the upper ends of the plurality of pressure springs (31) are fixedly connected to a lower grinding plate (27), and the upper end surface of the lower grinding plate (27) is arc-shaped. An upper grinding sheet (15) is provided at the upper end thereof, the lower end surface of the upper grinding sheet (15) is arc-shaped and matches the upper end surface of the lower grinding sheet (27), the upper end surface of the lower grinding sheet (27) and the lower end surface of the upper grinding sheet (15) are both frosted surfaces, the upper end of the upper grinding sheet (15) is evenly and fixedly connected with a liquid inlet pipe (25), the lower end of the liquid inlet pipe (25) passes through the upper grinding sheet (15) and the upper end is inclined to one side, the inner sides of both ends of the upper end surface of the upper grinding sheet (15) are fixedly connected with a linkage rod (24), the upper ends of the two linkage rods (24) are fixedly connected to the connecting plate (21), the inner wall of the upper grinding sheet (15) is evenly and fixedly connected with a plurality of clamping plates (28), and the upper grinding sheet (15) is engaged and rotatably connected with the liquid storage cylinder (14) through the clamping plates (28); A discharge assembly is provided on one side of the mixing tank (1), and the discharge assembly is used to assist the discharge of the ternary lithium-ion battery negative electrode composite material inside the mixing tank (1) to increase the discharge speed; the discharge assembly includes a piston cylinder (6) fixedly connected to one side of the mixing tank (1), a piston plate (18) is slidably connected inside the piston cylinder (6), and both sides of the lower end surface of the piston plate (18) are fixedly connected to return springs (17), and the lower ends of the two return springs (17) are fixedly connected to the inner bottom surface of the piston cylinder (6), the middle part of the upper end surface of the piston plate (18) is fixedly connected to the first steel wire rope (8), and one side of the middle part of the upper end surface of the piston plate (18) is fixedly connected to a push rod (19), and the upper end of the push rod (19) is fixedly connected to the lower end surface of the piston plate (18). The end is fixedly connected to an anti-slip frame (42), and the inner corners of the upper end of the anti-slip frame (42) are all provided with rounded corners. The middle part of the lower end surface of the piston cylinder (6) is fixedly connected to an air pipe (7), and the lower end of the air pipe (7) is fixedly connected to the discharge pipe (2). The lower end of the discharge pipe (2) is provided with a runner (16), and the axis of the runner (16) is fixedly connected to a driving rod (46), one end of the driving rod (46) passes through the discharge pipe (2) and extends into the interior of the air pipe (7) and is fixedly connected to a fan blade (47). The outer wall of the lower end of the air pipe (7) is evenly spaced and provided with a plurality of ventilation holes (45). The discharge assembly also includes a mounting frame (9) fixedly connected to one side of the upper end of the tank cover (4), and the upper end of the mounting frame (9) is fixedly connected to the upper end of the tank cover (4). One end of the first steel wire rope (8) is rotatably connected to a winding roller (10), the upper end of the first steel wire rope (8) is wound around the winding roller (10) and the tail end is fixedly connected to the winding roller (10), the middle part of the winding roller (10) is fixedly connected to a rotating shaft (41), one end of the rotating shaft (41) passes through the mounting frame (9) and a plurality of splines (39) are fixedly connected to the outer wall at even intervals, one end of the rotating shaft (41) fixedly connected to the splines (39) is slidably connected to a driven bevel gear (32), the end face of the driven bevel gear (32) close to the mounting frame (9) is engaged with a rotating plate (38), the end face of the rotating plate (38) close to the mounting frame (9) is fixedly connected to a resistance spring (37), the resistance spring (37) One end away from the rotating plate (38) is fixedly connected to the mounting frame (9), and the end surface of the rotating plate (38) close to the mounting frame (9) is fixedly connected to the side away from the conflict spring (37) with a second steel wire rope (40), and the end of the second steel wire rope (40) away from the rotating plate (38) is fixedly connected to the mounting frame (9). The discharge assembly also includes a support seat (35) fixedly connected to one side of the outer wall of the tank cover (4), and the upper end of the support seat (35) and the outer wall of the output end of the servo motor (5) inside the support frame (13) are fixedly connected to a pulley (34), and the outer sides of the two pulleys (34) are provided with a belt (20). The upper end of the pulley (34) on one side of the support seat (35) is fixedly connected to the active bevel gear (33).When the resisting spring (37) is in an uncompressed state, the driven bevel gear (32) is meshed with the active bevel gear (33), and a connecting spring (43) is fixedly connected to one side of the interior of the piston plate (18). One end of the connecting spring (43) is fixedly connected to a limiting rod (44). A limiting hole (36) is provided on one side of the upper end of the outer wall of the piston cylinder (6). The corners of the outer walls of the limiting hole (36) and the limiting rod (44) are both provided with rounded corners. When the piston plate (18) is located at the uppermost end of the piston cylinder (6), the limiting rod (44) is located inside the limiting hole (36) to limit the piston plate (18). In addition, the anti-slip frame (42) pushes the second steel wire rope (40) to bend.

2. A method for preparing a ternary lithium-ion battery negative electrode composite material, applied to the mixing device for the ternary lithium-ion battery negative electrode composite material according to claim 1, characterized in that: The following steps are involved: S1: Check whether the mixing tank (1), tank cover (4), feed pipe, and discharge pipe (2) are properly installed to ensure there is no leakage, connect the power supply, check whether the servo motor (5) and pipe clamp valve (3) are working properly, prepare the ternary lithium-ion battery negative electrode composite material to be mixed, and ensure that the material is free of impurities; S2: Add the material to be mixed into the mixing tank (1) through the feeding pipe, close the tank cover (4), ensure that it is well sealed, start the servo motor (5), drive the mixing assembly to work, and the connecting plate (21), connecting rod (12), disturbance ratchet rod (23), and spiral rotating rod (11) in the mixing assembly begin to rotate and flip, fully stirring the material and flipping the material from the bottom of the mixing tank (1) to the top. At the same time, the upper grinding plate (15), lower grinding plate (27), and pressure spring (31) in the grinding assembly start to work, grinding large particles in the material into small particles; S3: When the mixing and grinding reaches the predetermined time or effect, the servo motor (5) is turned off, the mixing and grinding work is stopped, the pipe clamp valve (3) on the discharge pipe (2) is ensured to be in a closed state, and the material is prepared for discharge. The piston plate (18), the air pipe (7), the fan blade (47), the runner (16), the winding roller (10), the first steel wire rope (8), the driven bevel gear (32), the driving bevel gear (33), and the limit rod (44) in the discharge assembly are checked to see whether they are in normal working condition; S4: Open the pipe clamp valve (3) on the discharge pipe (2), press the limit rod (44), and make the piston plate (18) move downward rapidly under the action of the return spring (17), compressing the air in the piston cylinder (6). The gas quickly enters the discharge pipe (2) through the air pipe (7), blowing the fan blade (47) to rotate, generating suction, and assisting the rapid discharge of materials.

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