Cathode material smelting furnace coating device and coating method

Abstract

The invention relates to the technical field of negative electrode material coating, in particular to a negative electrode material smelting furnace coating device and method.The coating kettle is internally provided with an inner bin for containing a negative electrode material, an extrusion mechanism and a spraying assembly, the extrusion mechanism comprises a plurality of sets of extrusion rollers and a rotating shaft, and a hollow flow channel in the rotating shaft is externally connected with negative pressure suction equipment; a plurality of groups of gauze elements are arranged on the side wall of the extrusion roller and are communicated with a hollow cavity in the extrusion roller, after a negative electrode material is extruded by the extrusion roller, redundant coating materials flow through the interior of the extrusion roller through the gauze elements and finally reach the interior of the hollow runner, and the spraying assembly is communicated with the hollow runner; the negative pressure suction equipment sucks the coating material through the hollow flow channel to enter the spraying assembly along the hollow flow channel, the spraying assembly sprays the coating material to form circulating flow, compared with a traditional coating device, the complex and tedious structural design is abandoned, the overall layout is more compact and reasonable, the occupied space is smaller, the equipment cost is reduced, and the coating efficiency is improved. And the production efficiency is also improved.

Description

Technical Field

[0001] The present invention relates to the technical field of negative electrode material coating, and particularly to a negative electrode material furnace coating device and a coating method. Background Art

[0002] In today's battery technology field, as a key component of the battery, the performance of the negative electrode material plays a decisive role in the overall performance of the battery, such as energy density, cycle life, charge and discharge rate, etc. With the rapid development of the new energy industry, especially in the fields of electric vehicles, energy storage systems, etc., the requirements for battery performance are becoming increasingly stringent, which makes the research and production of high-performance negative electrode materials the focus of the industry.

[0003] In the production process of negative electrode materials, the coating process is one of the key means to improve their performance. By coating specific materials on the surface of the negative electrode materials, the structural stability, conductivity, and compatibility with the electrolyte of the materials can be effectively improved. For example, in the negative electrode materials of lithium batteries, coating carbon materials can improve the electron conductivity of the materials, reduce the volume change during charge and discharge, and thus improve the cycle life and rate performance of the battery; coating metal oxides can enhance the stability of the materials and improve the safety of the battery.

[0004] For example, a Chinese invention patent with the patent application number 202411157911.5 discloses a super-high-performance negative electrode material coating system, including a coating kettle, a circulating flow mechanism, an extrusion and dispersion mechanism, and a dispersion blocking net; the circulating flow mechanism communicates with the discharge port at the bottom of the cavity and the top opening of the hollow flow channel on the stirring paddle, and this circulating flow mechanism circulates the negative electrode materials in the cavity to the hollow flow channel; the extrusion and dispersion mechanism is installed on the upper part of the stirring paddle, the extrusion and dispersion mechanism is located in the cavity, the extrusion chamber of the extrusion and dispersion mechanism communicates with the hollow flow channel, when the stirring paddle rotates, the pressure in the extrusion chamber fluctuates, extruding the negative electrode materials flowing out of the hollow flow channel, so that the negative electrode materials are ejected from the extrusion chamber; the dispersion blocking net is arranged in the cavity, this dispersion blocking net is rigidly arranged, and this dispersion blocking net flattens the negative electrode materials ejected by the extrusion and dispersion mechanism and filters out the excess molten coating materials on the surface of the negative electrode materials. However, this technical solution also has certain defects. It has many parts and a complex structure, which not only increases the manufacturing cost of the equipment, but also greatly improves the difficulty of equipment installation, debugging, and maintenance. The complex structure is also prone to deviations in the cooperation between components, affecting the stability and reliability of the coating effect.

[0005] Therefore, it is urgent to develop a new type of negative electrode material furnace coating device and coating method to solve the above problems in the prior art, improve the coating quality and production efficiency of negative electrode materials, and meet the growing market demand. Summary of the Invention

[0006] In view of the existing technical problems, the present invention provides a negative electrode material furnace coating device and a coating method. In terms of the device structure, through a uniquely designed extrusion mechanism, including the connection method between the extrusion roller and the rotating shaft and the setting of the screen mesh, the coating material can uniformly coat the negative electrode material, and at the same time, effectively extrude and disperse the negative electrode material and collect the excess coating material. The coordinated cooperation between the spraying assembly and the extrusion mechanism ensures the uniformity of the coating material during the cyclic spraying and mixing process. The ingenious cooperation between the limiting plate and the baffle not only realizes the uniform extrusion of the negative electrode material but also avoids the collision risk of the extrusion roller during operation, improving the stability of the equipment operation. In the coating method, through precise step design, from material feeding, mixing, extrusion dispersion and filtration, to the reverse adsorption and outflow of the coating material, and then to the final discharging, each step is strictly controlled to ensure that the dosage and coating thickness of the coating material can be accurately controlled, improving the consistency of product quality and reducing material waste at the same time.

[0007] To achieve the above object, the present invention provides the following technical solutions: A negative electrode material furnace coating device, comprising a coating kettle, wherein an inner chamber for accommodating the negative electrode material, an extrusion mechanism and a spraying assembly are arranged in the coating kettle. The inner chamber is arranged in a conical hopper shape, and the extrusion mechanism is arranged in the inner chamber. The extrusion mechanism includes a plurality of groups of extrusion rollers and a rotating shaft. The rotating shaft is rotatably arranged at the central axis of the coating kettle. A hollow flow channel is arranged in the rotating shaft, and the hollow flow channel is externally connected to a negative pressure suction device. The extrusion rollers are arranged in a circumferential equidistant array around the rotating shaft. While the extrusion rollers rotate synchronously with the rotating shaft, the extrusion rollers rotate around their own axes. The inside of the extrusion roller is hollow, and the extrusion roller is communicated with the hollow flow channel. A plurality of groups of screen meshes are arranged on the side wall of the extrusion roller and communicated with the internal hollow cavity. After the negative electrode material is extruded by the extrusion roller, the agglomerated coating material is extruded, and this part of the coating material enters the inside of the extrusion roller through the screen mesh and reaches the hollow flow channel for concentration. The spraying assembly is arranged inside the inner chamber. The spraying assembly is located above the extrusion mechanism and is communicated with the hollow flow channel. One-way valves are arranged at the positions where the material spraying pipes of the spraying assembly are communicated with the hollow flow channel. The negative pressure suction device sucks the coating material along the vacuum hollow flow channel and lifts it into the spraying assembly through the vacuum hollow flow channel. The spraying assembly sprays the coating material to form a cyclic flow.

[0008] As an improvement, a plurality of baffles are slidably arranged on the side wall of the inner bin, and the baffles intermittently lift and protrude into the inner bin, cooperate with the corresponding extrusion rollers, and extrude the negative electrode material located between the baffles and the extrusion rollers. When the extrusion rollers approach the baffles, the baffles descend and fall back to facilitate the extrusion rollers to cross the baffles.

[0009] As an improvement, the baffle is lifted and protruded by the rotation of the limiting plate arranged outside the inner bin. The limiting plate is installed in the coating kettle, and the limiting plate is arranged in a shape imitating the outer side wall of the inner bin. The two ends of the limiting plate are provided with inclined guiding surfaces at the parts in contact with and extruding the baffle. The limiting plate is sleeved on the rotating shaft and rotates synchronously with the rotating shaft.

[0010] As an improvement, the limiting plate includes a chassis and limiting blocks arranged at equal circumferential intervals along the axial direction of the chassis. The chassis is in sealing contact with the bottom flange of the inner bin. A chute is recessed on the upper end surface of the chassis. The bottom flange of the inner bin is provided with several groups of mounting holes corresponding to the chute, and balls are installed in the mounting holes. The balls are arranged to roll in the chute.

[0011] As an improvement, a gear ring is fixedly connected to the top of the inner bin. A gear is arranged at the end of the extrusion roller facing the gear ring. The gear meshes with the gear ring to drive the extrusion roller to rotate around its own axis.

[0012] As an improvement, a protective cover is arranged at the meshing part of the gear ring and the gear, and the protective cover isolates the gear ring and the gear.

[0013] As an improvement, a heating and heat preservation layer is sleeved outside the coating kettle. A cavity for carrying a heat transfer medium is arranged between the heating and heat preservation layer and the coating kettle. A thermometer is fixedly installed on the side wall of the heating and heat preservation layer, and the thermometer detects the temperature inside the coating kettle.

[0014] In addition, the present invention also provides a coating method for the negative electrode material melting furnace coating device, including the following steps: Step 1, material feeding: Feed the negative electrode material and the coating material into the inner bin through the feeding port on the top cover of the coating kettle. Step 2, material mixing: Start the top driving part, the driving part drives the rotating shaft to rotate, and the extrusion roller rotates synchronously with the rotating shaft. During the rotation process, the extrusion roller continuously rotates around its own axis in the inner bin to mix and stir the negative electrode material and the coating material. Step 3: Extrusion, dispersion and filtration. The inner bin rotates in the opposite direction with the rotating shaft. When the baffle plate contacts the limit plate, the baffle plate is lifted and protruded to form a blocking area on the side wall of the inner bin to limit the negative electrode material. At the same time, the extrusion roller extrudes and disperses the coating material in the limit area, and the excess coating material on the surface of the negative electrode material is filtered out through the gauze on the extrusion roller, and the excess coating material flows to the hollow flow channel. Step 4: The coating material is reversely adsorbed and flows out. The coating material in the hollow flow channel is sucked by an external negative pressure device. The coating material is lifted and flows along the axial direction of the hollow flow channel, and is sprayed into the inner bin through the spraying pipe in the spraying assembly. The coating material is evenly coated on the surface of the negative electrode material. Step 5: Discharging: Open the valve at the bottom of the coating kettle and discharge the negative electrode material from the inner bin through the discharge port for heating and carbonization.

[0015] As an improvement, in step three, when the limit plate contacts the baffle, the baffle extends, the width of the baffle in the inner bin is D1, and the distance between the squeezing roller and the inner wall of the inner bin is D2, satisfying the condition: D1>D2; When the limit plate is misaligned with the baffle, the baffle retracts, the width of the baffle in the inner bin is D3, and the distance between the squeezing roller and the inner bin wall is D2, satisfying the condition: D2>D3.

[0016] As an improvement, in step three, a one-way valve is provided on the hollow flow channel, and the one-way valve cooperates with an external negative pressure device. When the negative pressure device is started, the coating material in the hollow flow channel is controlled to flow in reverse.

[0017] The beneficial effects of the present invention are: (1) The present invention optimizes the coating process through a uniquely designed extrusion mechanism. Compared with the prior art, the coating device of the present invention is more compact and simple in structure. In the extrusion mechanism, the extrusion roller is connected to the rotating shaft, which ensures stability and high efficiency of power transmission during high-speed rotation. At the same time, the rotation of the extrusion roller enables the coating material to be evenly dispersed on the surface of the negative electrode material during the feeding process, thereby achieving preliminary uniform coating of the negative electrode material. In addition, the extrusion roller can also effectively extrude and disperse the negative electrode material, promote the close combination of the coating material and the negative electrode material, and the gauze can accurately collect the excess coating material on the surface of the negative electrode material to avoid material waste. (2) In the present invention, the limit plate and the baffle plate are cleverly matched. The limit plate is arranged in the same shape as the outer wall of the inner bin and is sleeved on the rotating shaft. The limit plate and the rotating shaft are arranged to rotate synchronously. The baffle plate can float up and down perpendicular to the side wall of the inner bin. When the two work together, they can accurately limit the negative electrode material to ensure that the negative electrode material is in the best position during the extrusion process, so that the extrusion roller can fully play its role and improve the extrusion effect. At the same time, when the limit plate and the baffle plate are misaligned, the baffle plate retracts to avoid collision between the extrusion roller and the baffle plate, thereby preventing equipment damage caused by collision, improving equipment operation stability, reducing equipment damage risks, reducing enterprise equipment maintenance costs, and ensuring smooth production. (3) The spraying pipes in the present invention are distributed in a circle with the rotating shaft as the center, so that the coating material can be spread out in all directions with the rotating shaft as the center when spraying, covering the negative electrode material in the inner bin in all directions, avoiding the occurrence of spraying dead corners, thereby ensuring that all positions of the negative electrode material can be evenly contacted with the coating material, greatly improving the uniformity of the coating, and effectively improving the consistency of product quality. Matching the rotation of the extrusion roller and the rotating shaft, when the extrusion roller and the rotating shaft rotate, the spraying pipe also moves accordingly, and the coating material sprayed by it can be better integrated with the negative electrode material being stirred in the dynamic process. While the extrusion roller stirs the negative electrode material to make it tumble continuously, the coating material sprayed from the circumferential direction can be continuously and evenly integrated into it, promoting a more complete mixing of the two and improving the coating effect; (4) In the present invention, the inner bin is connected to the rotating shaft through a gear transmission to realize the reverse rotation of the inner bin. The reverse rotation of the inner bin and the extrusion roller forms a dynamic shear field. When the extrusion roller rotates forward along the inner side surface of the inner bin, the inner bin rotates synchronously in the reverse direction, so that the negative electrode material is repeatedly kneaded and turned during the relative movement of the two, which significantly enhances the dispersion effect of the material and effectively avoids the problem of local agglomeration or uneven coating. During the extrusion dispersion process, the centrifugal force generated by the reverse rotation of the inner bin and the forward rotation of the extrusion roller form an offset, forcing the excess coating material to more efficiently flow back to the hollow flow channel through the gauze.

[0018] In summary, the present invention has the advantages of sophisticated structural design, efficient coordination, stability and safety, and is particularly suitable for the field of negative electrode material coating technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the three-dimensional structure of the stirring kettle of the present invention; Figure 2 This is a schematic diagram of the cross-sectional structure of a stirred tank according to the present invention; Figure 3 This is a schematic diagram of the internal structure of the stirring tank of the present invention; Figure 4 It is a schematic cross-sectional view of the internal structure of the stirring tank of the present invention; Figure 5 This is a schematic diagram of the connection structure between the inner bin and the extrusion mechanism of the present invention; Figure 6 Explosion structure schematic diagram of the inner bin and the limiting plate of the present invention; Figure 7 is Figure 6 The enlarged view at position A in; Figure 8 is Figure 6 The enlarged view at position B in; Figure 9 Schematic diagram of the three-dimensional structure of the inner bin of the present invention; Figure 10 Schematic diagram of the three-dimensional structure of the baffle of the present invention; Figure 11 Schematic diagram of the three-dimensional structure of the limiting plate of the present invention; Figure 12 Schematic diagram of the internal structure of the inner bin of the present invention; Figure 13 Schematic diagram of the connection structure between the rotating shaft and the spraying assembly; Figure 14 Schematic diagram of the three-dimensional structure of the squeezing roller.

[0020] In the figure: coating kettle 1, inner bin 11, mounting hole 111, mounting groove 112, baffle 113, limiting block 1131, gear ring 114, connecting part 115, gear set 116, driving gear 1161, driven gear 1162, tooth group 1163, kettle cover 12, inspection opening 121, feeding port 122, observation window 123, kettle body 13, heating and heat preservation layer 131, thermometer 132, discharging port 14, spraying assembly 2, material spraying pipe 21, through hole 211, extrusion mechanism 3, extrusion roller 31, screen 311, gear 312, protective cover 3121, connecting rod 313, sleeve 314, limiting projection 315, rotating shaft 32, hollow flow channel 321, limiting plate 33, chassis 331, sliding groove 3311, ball 3312, limiting hole 3313, blanking hole 3314, limiting block 332, guiding surface 333, limiting part 34. Detailed implementation manners

[0021] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0022] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation on the present invention.

[0023] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more unless otherwise specifically defined.

[0024] Example 1: As Figures 1-14 shown, the negative electrode material furnace coating device includes a coating kettle 1. An inner bin 11 for accommodating the negative electrode material, an extrusion mechanism 3, and a spraying assembly 2 are arranged in the coating kettle 1. The coating kettle 1 includes a kettle lid 12 and a kettle body 13. An inspection opening 121, a feeding port 122, and an observation window 123 are formed on the kettle lid 12. The inspection opening 121 is equipped with a sealing cover, which maintains good sealing performance in the non-inspection state to prevent heat dissipation or material leakage. The feeding port 122 is for conveying the negative electrode material and the coating material into the coating kettle 1, and at the same time, it can discharge the gas generated during the coating process. The observation window 123 is made of transparent quartz glass, and the operator can observe the working conditions inside the coating kettle 1 in real time through the observation window, such as the flow state of the material, the coating effect, etc. The kettle body 13 is fixedly connected to the kettle lid 12 by bolts; The inner bin 11 is arranged in a conical hopper shape. The conical hopper shape can utilize the gravity effect to make the negative electrode material flow downward more smoothly in the bin, avoid dead corners of material accumulation, ensure uniform distribution of the material in the bin, and provide a good material basis for subsequent processing procedures. The inner bin 11 is arranged in a shape similar to that of the coating kettle 1. The shape-similar arrangement can make the best use of the internal space of the coating kettle 1, avoid waste of space, and thus improve the production efficiency of the equipment. The extrusion mechanism 3 is arranged in the inner bin 11; The extrusion mechanism 3 includes several groups of extrusion rollers 31 and a rotating shaft 32. The rotating shaft 32 is driven by a motor and is rotatably arranged at the central axis of the coating kettle 1, ensuring the stability of the entire extrusion mechanism 3 and the balance of operation. A hollow flow channel 321 is arranged inside the rotating shaft 32, and the hollow flow channel 321 is externally connected to a negative pressure suction device. The negative pressure suction device can form a stable negative pressure environment inside the hollow flow channel 321, providing a power basis for subsequent suction of the extruded coating material. The extrusion rollers 31 are arranged in a circumferentially equidistant array around the rotating shaft 32. The equidistant array design enables the negative electrode material to receive uniform force during the extrusion process, avoiding situations of excessive local extrusion or insufficient extrusion. While the extrusion rollers 31 rotate synchronously with the rotating shaft 32, the extrusion rollers 31 are also self-rotating around their own axes. When the extrusion rollers 31 rotate synchronously with the rotating shaft 32, the extrusion rollers 31 can extrude the negative electrode material at different positions in the inner cavity 11, expanding the extrusion range. At the same time, when the extrusion rollers 31 rotate self, it can further enhance the extrusion effect on the negative electrode material, making it easier to separate the agglomerated coating material. The inside of the extrusion roller 31 is hollow, and the extrusion roller 31 is communicated with the hollow flow channel 321. This hollow structure not only reduces the overall weight of the extrusion roller, which is beneficial to reducing the load on the motor, but also provides sufficient space for the flow of the coating material. A number of groups of wire meshes 311 are arranged on the side wall of the extrusion roller 31 and are communicated with the internal hollow cavity. The wire meshes 311 connect the internal hollow cavity of the extrusion roller 31 with the outside. The wire meshes 311 can allow the extruded coating material to pass through while preventing large particles of the negative electrode material from entering the inside of the extrusion roller 31, playing a filtering role. After the negative electrode material is extruded by the extrusion roller 31, the agglomerated coating material is extruded. This part of the coating material enters the inside of the extrusion roller 31 through the wire meshes 311 and reaches the hollow flow channel 321 for concentration. This not only effectively separates and collects the excess coating material on the surface of the negative electrode material but also avoids interference of these coating materials with subsequent processes, improving the quality and efficiency of the entire coating process. The spraying assembly 2 is arranged inside the inner bin 11. The spraying assembly 2 is located above the extrusion mechanism 3 and is communicatively connected with the hollow flow channel 321. One-way valves are provided at the communicating positions between the material spraying pipes 21 of the spraying assembly 2 and the hollow flow channel 321. The one-way valves can strictly control the flow direction of the fluid and only allow the coating material to flow unidirectionally from the hollow flow channel 321 to the material spraying pipes 21 of the spraying assembly 2, effectively preventing the backflow phenomenon of the coating material and ensuring the stability and reliability of the operation of the entire system. The negative pressure suction device sucks the coating material along the hollow flow channel 321 and then enters the spraying assembly 2 after being lifted. The spraying assembly 2 sprays the coating material to form a circulating flow. Under the action of gravity, the coating material falls back to the bottom of the inner bin 11. Some of the coating materials that are not fully adsorbed by the negative electrode material are further separated by the action of the extrusion mechanism 3 again. Then, under the negative pressure generated by the negative pressure suction device, they are sucked into the spraying assembly 2 along the hollow flow channel 321 again. This cycle is repeated continuously, which not only improves the utilization rate of the coating material but also makes the coating layer on the surface of the negative electrode material more uniform and dense during multiple cycles of coating, effectively improving the overall quality and performance stability of the product.

[0025] It should be noted that the extrusion roller 31 and the rotating shaft 32 are connected by a connecting rod 313. One end of the connecting rod 313 is fixedly connected to the rotating shaft 32 to ensure that the connecting rod 313 and the rotating shaft 32 form a rigid whole. When the rotating shaft 32 rotates, the power can be stably transmitted to the extrusion roller 31. A sleeve 314 is provided at one end of the connecting rod 313 connected to the extrusion roller 31. The extrusion roller 31 is inserted into the sleeve 314 and can rotate freely within the sleeve 314. A limiting protrusion 315 is provided on the extrusion roller 31 corresponding to the sleeve 314. The limiting constraint between the limiting protrusion 315 and the sleeve 314 can effectively offset the external force that causes the axial movement of the extrusion roller, ensuring that the extrusion roller always remains in the established working position and maintaining a stable extrusion gap. This not only ensures the uniformity and consistency of material extrusion, improves product quality, but also reduces equipment wear and failures caused by the displacement of the extrusion roller, extends the service life of the equipment, and reduces maintenance costs.

[0026] In addition, a connecting portion 115 is provided at the top of the inner chamber 11 and extends towards the kettle lid. The connecting portion 115 is forged from a high-strength alloy material and has good mechanical properties and stability. A gear set 116 is provided at the top of the connecting portion 115. The connecting portion 115 is sleeved on the rotating shaft 32. The gear set 116 includes a driving gear 1161, a driven gear 1162, and a tooth group 1163 provided at the top end of the connecting portion 115. The driving gear 1161 is sleeved on the rotating shaft 32. The driving gear 1161, the driven gear 1162, and the tooth group 1163 are sequentially meshed and connected. When the rotating shaft 32 rotates, it drives the driving gear 1161 and the driven gear 1162 to rotate. The driven gear 1162 interacts with the tooth group 1163, thereby realizing the reverse rotation of the inner chamber 11. The rotation of the inner chamber 11 further promotes the mixing and dispersion of the negative electrode material inside, and cooperates with the extrusion mechanism 3 and the spraying assembly 2 to make the contact between the negative electrode material and the coating material more sufficient, greatly improving the coating effect.

[0027] Furthermore, the spraying assembly 2 includes a number of material spraying pipes 21 extending outward along the circumferential direction of the rotating shaft 32. A number of through holes 211 are formed in the material spraying pipes 21. The material spraying pipes 21 are inclined. The end of the material spraying pipe 21 connected to the hollow flow channel 321 is the highest point. Such a design can utilize the gravity effect, so that when the coating material flows through the material spraying pipe 21, it can flow more smoothly from high to low under the guidance of the inclination angle, avoiding the accumulation of the coating material in the pipe. At the same time, the inclined setting also helps to control the flow rate and flow volume of the coating material. As the coating material flows from high to low, the flow rate gradually increases. By adjusting the inclination angle, the spraying range of the coating material at the through holes 211 can be accurately controlled to ensure that the coating material evenly covers the negative electrode material in the inner chamber 11.

[0028] Furthermore, a plurality of baffles 113 are slidably provided on the side wall of the inner bin 11. The baffles 113 intermittently lift and protrude into the inner bin 11, and cooperate with the corresponding extrusion rollers 31 to extrude the negative electrode material between the baffles 113 and the extrusion rollers 31. The baffles 113, as a relatively fixed extrusion surface, cooperate with the rotating extrusion rollers 31 to effectively extrude the negative electrode material. This extrusion action can not only further disperse the agglomerates in the negative electrode material, but also It can improve the physical structure and performance of the negative electrode material, making it more conducive to the subsequent coating process, and when the extrusion roller 31 approaches the baffle 113, the baffle 113 drops back to facilitate the extrusion roller 31 to pass over the baffle 113. After the extrusion roller 31 passes over the baffle 113, the baffle 113 will lift the protrusion again according to the preset program, and continue to cooperate with the extrusion roller 31 that rotates next time to extrude the negative electrode material. This cycle is repeated to achieve continuous and efficient extrusion of the negative electrode material.

[0029] It should be further explained that a mounting groove 112 is provided on the inner bin 11 corresponding to the baffle 113, and the baffle 113 is inserted into the mounting groove 112. Limit blocks 1131 are provided on both sides of the baffle 113, and the limit blocks 1131 are extended along the length direction of the baffle 113. The limit blocks 1131 limit the position of the baffle 113 in the mounting groove 112 to prevent the baffle 113 from detaching from the mounting groove 112 due to excessive movement, thereby ensuring that it will not loosen or fall off during the operation of the equipment, thereby ensuring the safe and stable operation of the entire extrusion mechanism.

[0030] In addition, the baffle 113 is squeezed and pushed by the rotating limit plate 33 arranged outside the inner bin 11 to lift the protrusion. The limit plate 33 is installed in the coating kettle 1. The limit plate 33 is configured to be contoured with the outer wall of the inner bin 11. The contour design enables the limit plate 33 to maintain a constant gap with the wall of the inner bin 11 during the rotation process, effectively avoiding the limit plate 33 from getting stuck during the rotation process. The two ends of the limit plate 33 are provided with a sloped guide surface 333 at the position where the limit plate 33 contacts and squeezes the baffle 113. When the limit plate 33 rotates synchronously with the rotating shaft 32, the limit plate 33 is rotated synchronously with the rotating shaft 32. When rotating, the guide surface 333 will gradually contact the baffle 113. As the limit plate 33 continues to rotate, the guide surface 333 will apply an extrusion force to the baffle 113 in a smooth and gradual manner, so that the baffle 113 can be smoothly lifted and protruded into the inner chamber 11. This design avoids sudden and violent impacts, reduces equipment wear and the probability of failure, and also ensures the stability and controllability of the negative electrode material extrusion process. The limit plate 33 is sleeved on the rotating shaft 32, and the limit plate 33 is arranged to rotate synchronously with the rotating shaft 32.

[0031] Further, the limiting plate 33 includes a chassis 331 and limiting blocks 332 equidistantly arranged along the axial circumference of the chassis 331. The chassis 331 is in sealing contact with the bottom flange of the inner bin 11. A chute 3311 is recessed on the upper end surface of the chassis 331. A number of groups of mounting holes 111 are provided on the bottom flange of the inner bin 11 corresponding to the chute 3311. A ball 3312 is installed in the mounting hole 111. The ball 3312 is arranged to roll in the chute 3311, and the ball 3312 can freely roll in the chute 3311. This rolling cooperation method greatly reduces the friction between the chassis 331 and the bottom flange of the inner bin 11. When the limiting plate 33 rotates synchronously with the rotating shaft 32, the ball 3312 rolls in the chute 3311, making the rotation process smoother, reducing the energy consumption of the equipment, and at the same time reducing the heat and wear generated by friction, and prolonging the service life of the equipment.

[0032] Furthermore, a limiting hole 3313 for the rotating shaft 32 to pass through and a blanking hole 3314 for the negative electrode material to fall are provided on the chassis 331. A limiting portion 34 is provided at the bottom of the rotating shaft 32. The diameter of the limiting portion 34 is larger than the diameter of the rotating shaft 32. This design enables the limiting portion 34 to form an effective stepped limiting structure with the limiting hole 3313 on the chassis 331. When the chassis 331 is sleeved and installed on the rotating shaft 32, the upper surface of the limiting portion 34 is in close contact with the lower surface of the chassis 331. At the same time, the upper bottom surface of the chassis 331 abuts against the inner bin 11, restricting the axial movement of the limiting plate 33 along the rotating shaft 32 and ensuring that the limiting plate 33 always maintains a stable position during rotation.

[0033] It should be noted that a gear ring 114 is fixedly connected to the top of the inner bin 11. A gear 312 is provided at the end of the pressing roller 31 facing the gear ring 114. The gear 312 meshes with the gear ring 114 to drive the pressing roller 31 to rotate around its own axis. The self-rotation power of the pressing roller 31 comes from the process of the rotating shaft 32 driving its revolution. During the revolution, the pressing roller 31 can evenly press the negative electrode material at different positions. The self-rotation enables the screen 311 on the surface of the pressing roller 31 to continuously change the contact angle with the negative electrode material, further enhancing the stirring and dispersion effect on the negative electrode material, enabling the negative electrode material and the coating material to be more fully mixed, thereby improving the coating quality and production efficiency of the negative electrode material. By means of gear transmission, the self-rotation movement is carried out synchronously with the revolution movement, realizing the efficient utilization of energy. This design reduces the energy consumption and complexity of the equipment, reduces the manufacturing cost and operation cost of the equipment, and at the same time improves the energy utilization efficiency of the equipment.

[0034] Further, a protective cover 3121 is provided over the meshing portion of the gear ring 114 and the gear 312. The protective cover 3121 isolates the gear ring 114 from the gear 312. The protective cover 3121 can effectively prevent impurities such as dust, debris, and oil stains from entering the meshing area between the gear ring and the gear. If these impurities enter, they will exacerbate the wear of the gear and the gear ring, resulting in scratches, spalling and other damages on the tooth surface, reducing the accuracy and efficiency of gear transmission, and shortening its service life.

[0035] In addition, a heating and heat preservation layer 131 is provided outside the coating kettle 1. The heating and heat preservation layer 131 is fixedly connected to the kettle body 13. A cavity for carrying a heat transfer medium is provided between the heating and heat preservation layer 131 and the coating kettle 1. A thermometer 132 is fixedly installed on the side wall of the heating and heat preservation layer 131. The thermometer 132 detects the temperature inside the coating kettle 1. An inlet and an outlet for the heat transfer medium are provided on the heating and heat preservation layer 131. The heat transfer medium is usually hot water. The inlet is designed on one side of the heating and heat preservation layer 131, mainly for introducing high-temperature heat transfer medium, while the outlet is provided on the opposite side. Its function is to let the heat transfer medium that has completed the heat transfer task flow out so as to return to the heat source for heating or circulate to other links that require heat energy. The heat transfer medium forms a stable flow path in the heating and heat preservation layer 131, ensuring continuous and stable heat transfer, ensuring that the coating material in the coating kettle 1 can fully absorb heat and maintain a flowing state, thereby ensuring the uniformity and coating effect of the coating layer. At the same time, the heating and heat preservation layer 131 effectively blocks heat dissipation, improves the heat energy utilization efficiency, and reduces energy consumption.

[0036] Embodiment 2: The present invention also provides a coating method applied to the coating device for the negative electrode material melting furnace described in Embodiment 1, including the following steps: Step 1, material feeding: Feed the negative electrode material and the coating material into the inner cavity 11 through the feeding port on the top cover of the coating kettle 1. Step 2, material mixing: Start the top driving member. The driving member drives the rotating shaft 32 to rotate, and the extrusion roller 31 rotates synchronously with the rotating shaft 32. During the rotation, the extrusion roller 31 continuously rotates around its own axis in the inner cavity 11 to mix and stir the negative electrode material and the coating material. Step 3, extrusion, dispersion and filtration: The inner cavity 11 rotates in the opposite direction with the rotating shaft 32. When the baffle 113 abuts against the limiting plate 33, the baffle 113 raises the protrusion to form a blocking area on the side wall of the inner cavity 11 to limit the negative electrode material. Synchronously, the extrusion roller 31 extrudes and disperses the coating material in the limiting area, and filters out the excess coating material on the surface of the negative electrode material through the screen 311 on the extrusion roller 31. The excess coating material flows to the hollow flow channel 321. Step 4: Reverse adsorption and outflow of the coating material. The coating material in the hollow flow channel 321 is aspirated through an externally connected negative pressure device. The coating material flows upward along the axial direction of the hollow flow channel 321 and is sprayed into the inner chamber 11 through the material spraying pipe 21 in the spraying assembly 2. The coating material uniformly coats the surface of the negative electrode material. Step 5: Discharging. Open the valve at the bottom of the coating kettle 1, and discharge the negative electrode material from the inner chamber 11 through the discharge port 14 for heating and carbonization.

[0037] Among them, the wire mesh 311 is made of high-strength and corrosion-resistant stainless steel. This material not only has good mechanical strength and can withstand the centrifugal force generated by the rotation of the extrusion roller 31 and the impact force of the material, but also can resist the corrosion that the coating material and the negative electrode material may bring in a complex chemical environment, ensuring the structural stability of the wire mesh 311 and the accuracy of the mesh size. The pores of the wire mesh 311 only allow the coating material to pass through, ensuring that during the production process, the coating material can smoothly pass through the wire mesh and uniformly coat the surface of the negative electrode material, while the negative electrode material is blocked outside the wire mesh, ensuring the smooth progress of the coating process and the stability of the product quality.

[0038] Further, in Step 3, the extrusion roller 31 is arranged parallel to the inner wall of the inner chamber 11. When the limiting plate 33 abuts against the baffle 113, the baffle 113 extends. The width of the baffle 113 in the inner chamber 11 is D1, and the distance between the extrusion roller 31 and the inner wall of the inner chamber 11 is D2, satisfying the condition: D1 > D2, so that after the baffle 113 extends, it can effectively block the negative electrode material and form a stable limiting area. In this area, the extrusion roller 31 extrudes and disperses the negative electrode material. Due to the blocking effect of the baffle 113, the negative electrode material will not flow randomly, thus ensuring the uniformity of the extrusion effect. When the limiting plate 33 is misaligned with the baffle 113, the baffle 113 retracts. The width of the baffle 113 in the inner chamber 11 is D3, and the distance between the extrusion roller and the inner wall of the chamber is D2, satisfying the condition: D2 > D3, so that after the baffle 113 retracts, the extrusion roller 31 will not collide with the baffle 113 during rotation, ensuring the safe and stable operation of the equipment.

[0039] It should be noted that in Step 3, a one-way valve is provided on the hollow flow channel 321, and this one-way valve cooperates with an externally connected negative pressure device. When the negative pressure device is activated, the pressure inside the hollow flow channel 321 drops instantaneously, forming a negative pressure environment, controlling the reverse flow of the coating material inside the hollow flow channel 321. In this case, under the combined action of the strong suction force generated by the negative pressure and the self-gravity of the valve flap of the one-way valve, the valve flap quickly and tightly adheres to the valve seat to achieve complete sealing. At this time, since air molecules are small and have strong fluidity, it can be inhaled through the extremely small gap between the one-way valve and the valve seat under the action of negative pressure. However, due to the large particle size and strong viscosity of the coating material, it cannot break through the seal of the one-way valve, effectively preventing the reverse flow of the coating material. This not only ensures that during the negative pressure adsorption process, the coating material can be precisely controlled in a specific flow path, avoiding unnecessary backflow of the coating material, but also ensures that the negative pressure device can efficiently reverse-adsorb the excess coating material, creating conditions for subsequent material recycling and reuse, and greatly improving the efficiency and stability of the entire extrusion dispersion and filtration process.

[0040] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A negative electrode material melting furnace coating device, comprising a coating kettle (1), characterized in that: The coating kettle (1) is provided with an inner bin (11) for accommodating negative electrode materials, an extrusion mechanism (3) and a spraying assembly (2); the inner bin (11) is arranged in a conical bucket shape, and the extrusion mechanism (3) is arranged in the inner bin (11); The extrusion mechanism (3) comprises a plurality of groups of extrusion rollers (31) and a rotating shaft (32). The rotating shaft (32) is rotatably arranged at the central axis of the coating kettle (1). A hollow flow channel (321) is arranged in the rotating shaft (32). The hollow flow channel (321) is externally connected to a negative pressure suction device. The extrusion rollers (31) are arranged in an array at equal intervals around the circumference of the rotating shaft (32). The extrusion rollers (31) rotate synchronously with the rotating shaft (32) and rotate around themselves. The axis is arranged to rotate automatically, the interior of the squeezing roller (31) is hollow, the squeezing roller (31) is connected to the hollow flow channel (321), a plurality of groups of gauze (311) are arranged on the side wall of the squeezing roller (31) and are connected to the internal hollow cavity, after the negative electrode material is squeezed by the squeezing roller (31), agglomerated coating material is squeezed out, and this part of the coating material enters the squeezing roller (31) through the gauze (311) and reaches the hollow flow channel (321) for concentration; The spray assembly (2) is arranged inside the inner bin (11). The spray assembly (2) is located above the extrusion mechanism (3). The spray assembly (2) is connected to the hollow flow channel (321). A one-way valve is provided at the position where the spraying pipe (21) of the spray assembly (2) and the hollow flow channel (321) are connected. The negative pressure suction device sucks the coating material through the hollow flow channel (321) and lifts it along the hollow flow channel (321) into the spray assembly (2). The spray assembly (2) sprays the coating material to form a circulating flow.

2. The negative electrode material melting furnace coating device according to claim 1, characterized in that: A plurality of baffles (113) are slidably provided on the side walls of the inner bin (11); the baffles (113) intermittently rise and protrude into the inner bin (11) to cooperate with the corresponding squeezing rollers (31) to extrude the negative electrode material between the baffles (113) and the squeezing rollers (31); and when the squeezing rollers (31) approach the baffles (113), the baffles (113) fall back to facilitate the squeezing rollers (31) to pass over the baffles (113).

3. The negative electrode material melting furnace coating device according to claim 2, characterized in that: The baffle plate (113) is pushed and raised by a rotating limit plate (33) arranged outside the inner bin (11). The limit plate (33) is installed in the coating kettle (1). The limit plate (33) is arranged in a contour with the outer wall of the inner bin (11), and the two ends of the limit plate (33) are provided with sloped guiding surfaces (333) at the parts where they abut and squeeze the baffle plate (113). The limit plate (33) is sleeved on the rotating shaft (32), and the limit plate (33) is arranged to rotate synchronously with the rotating shaft (32).

4. The negative electrode material melting furnace coating device according to claim 3, characterized in that: The limit plate (33) comprises a bottom plate (331) and limit blocks (332) equidistantly arranged along the axial circumference of the bottom plate (331); the bottom plate (331) is sealed against the bottom flange of the inner bin (11); a slide groove (3311) is recessed on the upper end surface of the bottom plate (331); a plurality of groups of mounting holes (111) are arranged on the bottom flange of the inner bin (11) corresponding to the slide groove (3311); a ball bearing (3312) is installed in the mounting hole (111); and the ball bearing (3312) is rolled in the slide groove (3311).

5. The negative electrode material melting furnace coating device according to claim 1, characterized in that: A gear ring (114) is fixedly connected to the top of the inner bin (11), and a gear (312) is provided at the end of the squeezing roller (31) facing the gear ring (114); the gear (312) meshes with the gear ring (114) to drive the squeezing roller (31) to rotate along its own axis.

6. The negative electrode material melting furnace coating device according to claim 5, characterized in that: A protective cover (3121) is provided at the meshing portion between the gear ring (114) and the gear (312), and the protective cover (3121) isolates the gear ring (114) from the gear (312).

7. The coating method of the negative electrode material melting furnace coating device according to claim 1, characterized in that: The outer jacket of the coating kettle (1) is provided with a heating and heat-insulating layer (131), a cavity for carrying a heat-carrying medium is provided between the heating and heat-insulating layer (131) and the coating kettle (1), a thermometer (132) is fixedly mounted on a side wall of the heating and heat-insulating layer (131), and the thermometer (132) detects the temperature inside the coating kettle (1).

8. A coating method based on the negative electrode material melting furnace coating device according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: Adding materials: adding negative electrode materials and coating materials into the inner bin (11) through the material inlet on the top cover of the coating reactor (1); Step 2: Mixing the materials. The top driving member is started, and the driving member drives the rotating shaft (32) to rotate. The squeezing roller (31) rotates synchronously with the rotating shaft (32). During the rotation process, the squeezing roller (31) continuously rotates around its own axis in the inner bin (11) to mix and stir the negative electrode material and the coating material. Step 3: extrusion, dispersion and filtration. The inner bin (11) rotates in the opposite direction to the rotation shaft (32). When the baffle (113) contacts the limiting plate (33), the baffle (113) is lifted and protruded to form a blocking area on the side wall of the inner bin (11) to limit the negative electrode material. Simultaneously, the extrusion roller (31) extrudes and disperses the coating material in the limiting area, and filters out excess coating material on the surface of the negative electrode material through the gauze (311) on the extrusion roller (31). The excess coating material flows into the hollow flow channel (321). Step 4: reverse adsorption and outflow of the coating material, the coating material in the hollow flow channel (321) is sucked by an external negative pressure device, the coating material is lifted and flows along the axial direction of the hollow flow channel (321), and is sprayed into the inner bin (11) through the spraying pipe (21) in the spraying assembly (2), and the coating material is evenly coated on the surface of the negative electrode material; Step 5: Discharging the material. Open the valve at the bottom of the coating reactor (1) and discharge the negative electrode material from the inner bin (11) through the discharge port (14) for heating and carbonization.

9. The coating method of the negative electrode material melting furnace coating device according to claim 8, characterized in that: In step three, when the limiting plate (33) contacts the baffle (113), the baffle (113) extends out, the width of the baffle (113) in the inner bin (11) is D1, and the distance between the squeezing roller (31) and the inner wall of the inner bin (11) is D2, satisfying the condition: D1>D2; When the limiting plate (33) and the baffle (113) are misaligned, the baffle (113) retracts, the width of the baffle (113) in the inner bin (11) is D3, and the distance between the squeezing roller and the inner bin wall is D2, satisfying the condition: D2>D3.

10. The coating method of the negative electrode material melting furnace coating device according to claim 8, characterized in that: In step three, a one-way valve is provided on the hollow flow channel (321), and the one-way valve cooperates with an external negative pressure device. When the negative pressure device is activated, the coating material in the hollow flow channel (321) is controlled to flow in the reverse direction.

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