Device and method for realizing continuous atomic-scale coating of powder

Abstract

The invention relates to the technical field of atomic layer deposition, in particular to a device and method for achieving continuous atomic-scale coating of powder. The device for achieving continuous atomic-scale coating of the powder comprises a rack, a reaction chamber arranged on the rack according to an assembly line, a reaction pipe section transversely penetrating through the reaction chamber and a rotation driving device arranged on the rack and used for driving the reaction pipe section to rotate around a shaft, and the reaction pipe section is of a porous structure which is breathable and can prevent the powder from running out. One end of the reaction pipe section is provided with a feed port, the other end of the reaction pipe section is provided with a discharge port, the reaction chamber comprises a first chamber, a second chamber, a third chamber and a fourth chamber, and air supply modules for blowing air to the reaction pipe section are arranged in the first chamber, the second chamber, the third chamber and the fourth chamber; and exhaust modules for exhausting are arranged in the first chamber, the second chamber, the third chamber and the fourth chamber. The technical problem that efficient, continuous and controllable atomic-scale coating of powder materials is difficult to achieve is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of atomic layer deposition, and in particular to a device and method for achieving continuous atomic-level coating of powders. Background Art

[0002] In the field of powder material surface treatment technology, surface coating modification of powder materials is an important means to enhance their performance and expand their application range. By coating the surface of powder materials, the interfacial behavior and performance of the powder can be significantly improved, meeting the stringent requirements of different application fields for material surface functions.

[0003] Currently, surface coating methods for powder materials primarily include physical vapor deposition (PVD), wet chemical coating, and chemical vapor deposition (CVD). While PVD can produce relatively uniform thin films, it often requires high vacuum, resulting in high costs and limited production capacity. Wet chemical coating offers a simple process and is easily scalable, but has limitations in terms of film uniformity and controllability. Conventional CVD technology can produce films of high purity and density, but struggles to precisely control thickness at the atomic level.

[0004] In recent years, atomic layer deposition (ALD), as a special chemical vapor deposition technology, has been able to build thin films layer by layer on the surface of solid substrates and achieve precise thickness control at the atomic scale by virtue of its "self-limiting adsorption-surface saturation reaction-gas phase cleaning" cycle. The main principle of ALD technology is: during the deposition process, at least two precursors (precursor A and precursor B) alternately enter the reaction chamber at different times and spaces, and self-limiting chemical adsorption and surface reaction occur on the substrate surface. After alternating cycles, a highly conformal, uniform atomic-level thin film gradually grows on the surface of the powder particles. Compared with conventional CVD, ALD can achieve continuous atomic-level control of film thickness, greatly improving the uniformity, repeatability and conformality of the coating layer. Therefore, it is widely used in high-precision coatings, nanostructured materials, and functional thin film preparation.

[0005] However, the traditional thin film ALD process is mainly aimed at flat plates, thin films or large porous materials. It still faces many technical challenges for the coating of bulk powders, especially in continuous production scenarios. Most traditional ALD processes use intermittent reaction chambers, and perform alternating injection, adsorption and cleaning of precursors under static or low flow rate conditions, which makes it difficult to meet the needs of continuous flow coating of large amounts of powders. To achieve high-yield, industrial continuous production, it is necessary to maintain continuous movement and efficient circulation of powders in the reaction zone, and to ensure strict isolation and precise alternation of different precursors. However, existing intermittent or batch ALD devices cannot overcome the above contradictions.

[0006] While the concept of spatial ALD (S-ALD) offers a new approach to continuous production, currently reported powder S-ALD solutions still suffer from significant shortcomings in process and equipment structure. For example, some solutions suffer from severe precursor backmixing, excessively long equipment, difficult processing and maintenance, low precursor utilization due to high airflow velocities, and poor adaptability to gas / solid flows with high particle loads or single-particle flows.

[0007] In summary, there is an urgent need for a new method and equipment for continuous atomic layer deposition of powders to solve the key bottlenecks in the existing technology, such as the difficulty in achieving continuity of atomic layer deposition equipment, easy cross-contamination of precursors, and uneven coating caused by insufficient gas-solid contact, so as to achieve high-yield and high-uniformity atomic-level thin film deposition to meet the needs of industrial production. Summary of the Invention

[0008] Therefore, to address the above-mentioned issues, the present invention proposes a device for achieving continuous atomic-level coating of powders. This device aims to overcome the shortcomings of the existing technology and, through innovative design concepts and technical means, achieve efficient, continuous, and controllable atomic-level coating of powder materials, providing strong support for the industrial application of powder materials in multiple fields. Based on this, a method for achieving continuous atomic-level coating of powders is also proposed.

[0009] To achieve the above object, the present invention adopts the following technical solutions: A device for achieving continuous atomic-level coating of powders, comprising a frame and a reaction chamber arranged on the frame according to an assembly line, a reaction tube section transversely passing through the reaction chamber, and a rotation drive device arranged on the frame for driving the reaction tube section to rotate around an axis, wherein the reaction tube section is a porous structure that is breathable and prevents powder from escaping, one end of the reaction tube section is provided with a feed port, and the other end is provided with a discharge port, the reaction chamber comprises a first chamber, a second chamber, a third chamber and a fourth chamber, each of the first chamber, the second chamber, the third chamber and the fourth chamber is provided with an air supply module for blowing air into the reaction tube section, and each of the first chamber, the second chamber, the third chamber and the fourth chamber is provided with an exhaust module for exhausting air.

[0010] Furthermore, a heating device for heating the reaction chamber is detachably provided on the reaction chamber, and the heating device can respectively control the temperatures of the first chamber, the second chamber, the third chamber and the fourth chamber.

[0011] Furthermore, the gas supply module of the first chamber supplies a first precursor, the gas supply module of the third chamber supplies a second precursor, and the gas supply modules of the second chamber and the fourth chamber supply an inert gas.

[0012] Furthermore, the exhaust module is a vacuum pump, and the first chamber, the second chamber, the third chamber, and the fourth chamber are provided with independent vacuum pumps. Furthermore, the frame is provided with a spiral feeding device at the feed inlet, and a cyclone separator at the discharge outlet.

[0013] Furthermore, the reaction tube section is tilted from the first chamber to the fourth chamber and tilted from top to bottom to achieve smooth discharge, and the frame is provided with a height adjustment device for adjusting the tilt angle of the reaction tube section.

[0014] Furthermore, the pore size of the reaction tube section is 100 mesh-10000 mesh.

[0015] Based on the same inventive concept, a method for applying to a device for achieving continuous atomic-level coating of powders is also proposed, comprising the following steps: S1. The heating device is preheated to the reaction temperature of the reaction chamber, the reaction tube section rotates, and then the powder particles are input into the reaction tube section and enter the first chamber. A first precursor for reaction is introduced into the first chamber, and the exhaust module exhausts the gas to achieve reaction of the powder particles in the first chamber; S2. After the powder particles react completely in the first chamber, the powder particles continuously move into the second chamber. The second chamber is introduced with a cleaning gas, and the exhaust module exhausts the gas, thereby cleaning the powder particles in the second chamber and discharging excess first precursor. S3. After cleaning, the powder particles continuously move into the third chamber, a second precursor for reaction is introduced into the third chamber, and the exhaust module exhausts the gas to achieve reaction of the powder particles in the third chamber; S4. After the powder particles react completely in the third chamber, they continue to move into the fourth chamber. A cleaning gas is introduced into the fourth chamber, and the exhaust module exhausts the gas, thereby cleaning the powder particles in the fourth chamber and discharging excess second precursor. S5. After cleaning is completed, the powder particles are output.

[0016] Furthermore, when the powder particles need to be coated for multiple cycles, the powder particles in step S5 are output to the first chamber for cyclic reaction, or a combination module formed by the first chamber, the second chamber, the third chamber and the fourth chamber with the same number of coating cycles is continued to be connected and set at the rear end of the fourth chamber.

[0017] Furthermore, the cleaning gas introduced into the second chamber or the fourth chamber is nitrogen or argon.

[0018] By adopting the above technical solution, the beneficial effects of the present invention are: 1. This solution realizes the continuous feeding, processing and discharging of powder particles, greatly improving production efficiency. By rotating the reaction tube section, the powder particles are constantly turned over during the reaction process, ensuring the uniformity of the coating layer. At the same time, the airflow can form blowing forces at different angles for the same pore, effectively preventing powder particles from clogging the pores, further ensuring the continuity and stability of the coating process. The design of the multi-stage reaction chamber enables different precursors and inert gases to act in independent spaces, avoiding cross-contamination and improving the utilization rate of the precursors. Through the blowing of the airflow, the powder particles will also form a spiral state in the reaction tube section. This spiral flow not only enhances the contact efficiency between the powder particles and the precursor, but also promotes the uniform dispersion between the particles, further improving the coating effect.

[0019] 2. The temperature of each chamber can be independently adjusted based on the reaction requirements of different precursors to ensure optimal reaction conditions. The removable heating device facilitates subsequent cleaning, maintenance, and replacement, reducing maintenance costs. Independently regulating the temperature of each chamber helps precisely control the reaction process and optimize the quality and performance of the coating.

[0020] 3. Independently distributing precursors and inert gases avoids cross-contamination between different precursors, ensuring the purity of the coating layer. The inert gas supply in the second and fourth chambers effectively cleans excess precursors and byproducts from the powder particle surface, improving coating quality. The specifically distributed gas supply module design simplifies the operating process and improves production efficiency.

[0021] 4. The vacuum pump can quickly and effectively exhaust excess gas and byproducts from the chamber, maintaining stable pressure within the chamber. The independent vacuum pump system avoids gas crosstalk between different chambers, ensuring reaction accuracy. Stable chamber pressure and precise gas control help improve coating efficiency and quality.

[0022] 5. The spiral feeder ensures continuous and uniform feeding of powder particles, ensuring continuous production. The cyclone separator achieves gas-solid separation at the discharge port, efficiently collecting the coated powder particles while recovering excess gas. The automated design of the feed and discharge mechanism reduces manual intervention, improving production efficiency and product quality stability.

[0023] 6. The tilted reaction tube section utilizes gravity to ensure that the powder particles can continuously move through different reaction chambers and are smoothly discharged after the reaction is completed. The setting of the height adjustment device allows the tilt angle of the reaction tube section to be adjusted according to the requirements of different atomic layer deposition processes, optimizing the residence time of the powder particles, the discharge speed and the coating effect. By coordinating the tilt angle and rotation speed of the reaction tube section, the adjustability of the discharge speed and residence time can be guaranteed, allowing the device to adapt to powder particles of different particle sizes and densities and different thin film deposition process requirements, thereby improving the adaptability and flexibility of the device.

[0024] 7. Appropriate pore size ensures gas permeability while effectively preventing powder particles from escaping, ensuring the smooth progress of the reaction. The choice of pore size has a significant impact on the uniformity and density of the coating layer. An appropriate pore size helps improve coating quality. Combined with the blowing force generated by the rotation at different angles, a moderate pore size further reduces the risk of powder particles clogging the pores and improves the stability of the device's operation.

[0025] 8. Through a continuous, automated process, efficient atomic-level coating of powder particles is achieved, improving production efficiency. Precise control of reaction conditions (such as temperature, gas flow rate, and reaction time) at each step ensures controllable quality of the coating layer. During rotation, the airflow propels the powder particles into a spiral, enhancing contact between the particles and the precursor and promoting uniform coating.

[0026] 9. Through cyclic reactions, multi-cycle coating of powder particles is achieved, meeting the coating thickness requirements of different applications. Multi-cycle coating helps to further improve the uniformity, density and performance of the coating layer, broadening the application range of powder materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the present invention.

[0028] Figure 2 It is a schematic diagram of the cross-sectional structure of the reaction chamber.

[0029] Figure 3 This is a graph showing the relationship between the actual number of coatings on powder particles and film thickness.

[0030] Figure 4 This is a structural diagram of the first nozzle layout method of the air supply module.

[0031] Figure 5 This is a structural diagram of the second nozzle layout method of the air supply module.

[0032] Figure 6 This is a transmission electron microscope image of the surface of Al2O3 particles coated with silicon oxide film.

[0033] Reference numerals: 1. Frame; 2. Reaction chamber; 21. First chamber; 22. Second chamber; 23. Third chamber; 24. Fourth chamber; 3. Reaction tube section; 31. Feed inlet; 32. Discharge outlet; 33. Spiral feeding device; 34. Cyclone separator; 4. Rotation drive device; 5. Air supply module; 51. Transverse drive mechanism; 52. Nozzle; 6. Exhaust module; 61. Filter mechanism; 7. Heating device; 8. Height adjustment device. DETAILED DESCRIPTION

[0034] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0035] refer to Figure 1 The present embodiment provides an apparatus for achieving continuous atomic-level coating of powders, comprising a frame 1 and a reaction chamber 2 arranged on the frame 1 according to an assembly line, a reaction tube section 3 transversely passing through the reaction chamber 2, and a rotation drive device 4 arranged on the frame 1 for driving the reaction tube section 3 to rotate around an axis. The reaction tube section 3 is a porous structure that is breathable and prevents powder from escaping. A feed port 31 is provided at one end of the reaction tube section 3, and a discharge port 32 is provided at the other end. The reaction chamber 2 includes a first chamber 21, a second chamber 22, a third chamber 23, and a fourth chamber 24. An air supply module 5 for blowing air into the reaction tube section 3 is respectively provided in the first chamber 21, the second chamber 22, the third chamber 23, and the fourth chamber 24. An exhaust module 6 for exhausting air is provided in the first chamber 21, the second chamber 22, the third chamber 23, and the fourth chamber 24.

[0036] The first chamber 21, the second chamber 22, the third chamber 23, and the fourth chamber 24 may not be interconnected, with the reaction tube section 3 being the only means for the passage of powder particles. Furthermore, the reaction tube section 3 may also be provided with automatic isolation doors (not shown, but those skilled in the art will appreciate the location and method of the automatic isolation doors) to prevent powder particles from entering different chambers. The automatic isolation doors may employ solenoid valves or mechanical lift doors. The reaction tube section 3 is constructed using a porous ceramic or stainless steel filter screen, or alternatively, metal fiber felt, sintered metal porous material, or other materials. The pore size is 500 mesh (preferably, ranging from 100 mesh to 10,000 mesh), ensuring both air permeability and effective prevention of powder escape. Both the feed port 31 and the discharge port 32 are connected to the reaction tube section 3 via mechanical seals, ensuring that the feed port 31 and the discharge port 32 remain stationary during rotation of the reaction tube section 3. For example, a rolling shaft mechanical seal may be employed to achieve independent rotation of the reaction tube section 3. A stepper motor or servo motor is used as the rotation drive 4, in conjunction with a reducer to achieve more precise speed control. Connected to the reaction tube 3 via a rolling shaft, it drives the reaction tube 3 to rotate about its axis, with an adjustable speed range of 1 rpm to 200 rpm. The combination of the first chamber 21, the second chamber 22, the third chamber 23, and the fourth chamber 24 can be repeatedly arranged to form a multi-cycle reaction.

[0037] The reaction chamber 2 is detachably provided with a heating device 7 for heating the reaction chamber 2. The heating device 7 is capable of separately regulating the temperatures of the first chamber 21, the second chamber 22, the third chamber 23 and the fourth chamber 24. The heating device 7 adopts resistance wire heating or infrared heating. The heating method can also be replaced by microwave heating or electromagnetic induction heating to improve heating efficiency and temperature uniformity. It is connected to the reaction chamber 2 through a mechanical seal, and the detachable design facilitates later cleaning and maintenance. The heating device 7 is divided into four independently controlled temperature zones, corresponding to the first chamber 21, the second chamber 22, the third chamber 23 and the fourth chamber 24 respectively. The temperature of each temperature zone can be adjusted independently, and the adjustment range is 20°C-400°C.

[0038] The gas supply module 5 of the first chamber 21 supplies the first precursor, the gas supply module 5 of the third chamber 23 supplies the second precursor, and the gas supply modules 5 of the second chamber 22 and the fourth chamber 24 supply an inert gas. The first and second precursors can be selected according to actual needs. The inert gas can be nitrogen, argon, or helium, as long as it does not chemically react with the first and second precursors and the powder particles. The inert gas can also be selected according to actual needs, and the flow rate and speed of the inert gas can also be selected according to actual needs.

[0039] The exhaust module 6 is a vacuum pump, and the first chamber 21, the second chamber 22, the third chamber 23, and the fourth chamber 24 are provided with independent vacuum pumps. The exhaust module 6 can be replaced with other forms of exhaust devices, such as a blower or an exhaust fan, as long as the gas in the chamber can be effectively discharged. The second chamber 22 and the fourth chamber 24 can also share a vacuum pump. The gas discharged from the first chamber 21, the second chamber 22, the third chamber 23, and the fourth chamber 24 can be recycled after treatment. A filter mechanism 61 is provided at the exhaust module 6, and the aperture of the filter mechanism 61 should be smaller than the aperture of the reaction tube section 3.

[0040] The frame 1 is provided with a spiral feeder 33 at the feed port 31, and a cyclone separator 34 at the discharge port 32. The spiral feeder 33 and the cyclone separator 34 are conventional devices in the art and can be replaced by other devices with similar functions.

[0041] The reaction tube segment 3 is tilted from the first chamber 21 to the fourth chamber 24, and tilted from top to bottom to achieve smooth discharge. The frame 1 is provided with a height adjustment device 8 for adjusting the tilt angle of the reaction tube segment 3. The height adjustment device 8 can be a combination of one or more connecting rod mechanisms, air cylinders, oil cylinders, and electric push rods.

[0042] A method for realizing continuous atomic-level coating of powders, comprising the following steps: S1, the heating device 7 is preheated to the reaction temperature of the reaction chamber 2, the reaction tube section 3 rotates, and then the powder particles are input into the reaction tube section 3 and enter the first chamber 21. The first precursor for reaction is introduced into the first chamber 21, and the exhaust module 6 exhausts the gas to achieve the reaction of the powder particles in the first chamber 21; S2. After the powder particles react completely in the first chamber 21, they continuously move into the second chamber 22. The second chamber 22 is fed with a cleaning gas, and the exhaust module 6 exhausts the gas, thereby cleaning the powder particles in the second chamber 22 and discharging excess first precursor. S3. After cleaning, the powder particles continuously move into the third chamber 23. A second precursor for reaction is introduced into the third chamber 23, and the exhaust module 6 exhausts the gas to achieve reaction of the powder particles in the third chamber 23. S4: After the powder particles react completely in the third chamber 23, they continue to move into the fourth chamber 24. The fourth chamber 24 is fed with a cleaning gas, and the exhaust module 6 exhausts the gas, thereby cleaning the powder particles in the fourth chamber 24 and discharging excess second precursor. S5. After cleaning is completed, the powder particles are output.

[0043] When it is necessary to coat the powder particles for multiple cycles, the powder particles of step S5 are output to the first chamber 21 for cyclic reaction. That is, the powder particles of step S5 are output to step S1 for cyclic reaction until the reaction cycle is reached, and then output. Or a combination formed by the first chamber 21, the second chamber 22, the third chamber 23 and the fourth chamber 24 is set after the fourth chamber 24 to achieve multi-cycle coating. The combination formed by the first chamber 21, the second chamber 22, the third chamber 23 and the fourth chamber 24 can be multiple, that is, if several cycles of coating are required, several combinations are set. In actual applications, the more times the cyclic reaction is performed, the thicker the coating film will be. Figure 3 As shown in FIG. 1 , it is a graph showing the relationship between the actual number of coating times of a certain type of powder particles and the film thickness.

[0044] In addition, for multi-period coating, a combination of the first chamber 21, the second chamber 22, the third chamber 23 and the fourth chamber 24 is added. By selecting different precursor combinations, mixed deposition of different thin films can be achieved to form hybrid functional films.

[0045] The air supply module 5 is provided with a plurality of nozzles 52, and the number and arrangement of the nozzles 52 can be adjusted according to the needs. The structure of the nozzle can be flat, circular, etc. The distribution of the nozzles 52 can be set on a plane or on an arc surface, such as Figure 4 、 Figure 5 As shown, other arrangements are also possible. For better gas-solid contact and more efficient precursor utilization, the nozzles 52 can be arranged in a single row or in an array. The purpose is to blow air to the powder particles in the reaction tube section, thereby achieving tumbling of the powder particles, thereby making the powder particles react more fully. The structure and setting of the air supply module 5 can be adjusted according to actual needs. Its purpose is to achieve blowing of the powder particles in the reaction tube section 3, thereby achieving rotation of the powder particles and achieving a better and more uniform reaction.

[0046] Refer again Figure 2 , which is a schematic cross-sectional view of the reaction chamber 2, wherein the reaction tube segment 3 rotates counterclockwise, while the powder particles in the reaction tube segment 3 rotate clockwise. The gas supply module 5 is not located directly below the reaction tube segment 3; it is offset from the center by a distance L. The inner diameter of the reaction tube segment 3 is r, satisfying L / r = 0.7 to 0.8.

[0047] Since the reaction tube 3 rotates counterclockwise while the powder particles rotate clockwise, the two rotate in opposite directions, which forms a complex spiral flow inside the reaction tube 3. This spiral flow can significantly enhance the contact between the powder particles and the precursor gas, improving the efficiency of the gas-solid reaction.

[0048] The offset design of the gas supply module 5 and the center of the reaction tube section 3 not only forms a clockwise airflow, but also creates turbulence in the local area, further increasing the contact opportunities between the powder particles and the precursor gas, and helping to improve the uniformity and density of the coating layer.

[0049] The combined effects of spiral flow and localized turbulence ensure a more uniform coating of the powder particles within reaction tube section 3, reducing the unevenness of the coating layer. Due to the enhanced gas-solid contact, the precursor gas can react more quickly with the surface of the powder particles, thereby improving coating efficiency and shortening the production cycle.

[0050] The clockwise rotation of the powder particles combined with the counterclockwise rotation of the reaction tube segment 3 creates a dynamic blockage-clearing mechanism. This mechanism helps reduce blockage of the pores of the reaction tube segment 3 by powder particles, maintaining the air permeability of the reaction tube segment 3. The offset design of the air supply module 5 ensures more uniform airflow distribution within the reaction tube segment 3, reducing the risk of blockage caused by excessive or insufficient local airflow.

[0051] The L / r ratio is between 0.7 and 0.8, a relatively optimal range. This ratio can be adjusted based on actual production requirements to accommodate powders of varying sizes and densities, as well as the reactive properties of different precursor gases. This design allows the device to adapt to a wider range of production conditions, enhancing its flexibility and adaptability.

[0052] In addition, a transverse driving mechanism 51, such as a screw mechanism, can also be set up to move the air supply module 5, thereby changing the value of L and thus achieving adjustable blowing effect of the airflow. The part of the air supply module 5 in the reaction chamber 2 is the air supply box.

[0053] In practical applications, the Figure 5 The air supply module 5 shown has a better effect, and can be matched with the circular tubular reaction tube section 3 to achieve a better airflow blowing effect.

[0054] This solution achieves continuous atomic-level coating of powder particles. Compared with batch processes, it has the following advantages: 1. Increased production capacity: The continuous process can increase the production capacity per unit time by at least dozens of times compared to the batch process, and can even reach thousands of times in industrial systems; 2. Process stability: Maintain coating quality comparable to small-scale batch systems while meeting the demands of large-scale production; 3. Ultra-high consistency: The continuous process can achieve high consistency in coating quality, thus avoiding the problem of inconsistent coating quality between batches in the intermittent process.

[0055] It can be seen that the continuous ALD process of powder particles shows overwhelming production efficiency advantages in industrial large-scale production.

[0056] Take the continuous deposition of SiO2 film on the surface of Al2O3 particles as an example: The porous reaction tube section 3 has an inner diameter of 10 cm and a 300-mesh pore size. Al2O3 nanoparticles with an average particle size of 250 mesh (approximately 60 μm) were used as the substrate, with silicon tetrachloride (SiCl4) as the first precursor and deionized water (H2O) as the second precursor. The purge gas used was 99.999% high-purity nitrogen. The gas flow rate to the first chamber 21 was set at 3 L / min and the temperature was set at 150°C. The gas flow rate to the second chamber 22 was set at 3 L / min and the temperature was set at 150°C. The gas flow rate to the second chamber 22 and the fourth chamber 24 was set at 5 L / min, and the temperature was both set at 150°C. Al2O3 particles were continuously fed from the feed port 31 via a spiral feeder 33 at a rate of 100 g / min. The inclination angle of the reaction tube section 3 was set at 5°, and the rotation speed of the reaction tube section 3 was set at 40 rpm to ensure that the particles continuously passed through the first chamber 21 to the fourth chamber 24 while maintaining uniform dispersion and high gas-solid contact efficiency. The particles were collected from the rear end of the fourth chamber 24 and then returned to the feed port 31. This step was repeated 20 times, achieving 20 cycles of continuous coating of the Al2O3 particles.

[0057] like Figure 6 As shown in FIG, it is a transmission electron microscope image of the silicon oxide film coated on the surface of the Al2O3 particles. From the TEM characterization image, it can be seen that after 20 consecutive atomic layer deposition coating cycles of the Al2O3 particles, a uniform and dense silicon oxide film grows on the surface of the Al2O3 particles, showing a high degree of shape preservation.

[0058] Although the present invention has been particularly shown and described in conjunction with preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made to the present invention without departing from the spirit and scope of the invention as defined in the appended claims, and all such changes are within the scope of protection of the present invention.

Claims

1. A device for achieving continuous atomic-level coating of powders, characterized by: The invention comprises a frame (1), a reaction chamber (2) arranged on the frame (1) according to an assembly line, a reaction tube section (3) transversely passing through the reaction chamber (2), and a rotation drive device (4) arranged on the frame (1) for driving the reaction tube section (3) to rotate around an axis, wherein the reaction tube section (3) is a porous structure that is breathable and prevents powder from escaping, a feed port (31) is provided at one end of the reaction tube section (3), and a discharge port (32) is provided at the other end, the reaction chamber (2) comprises a first chamber (21), a second chamber (22), a third chamber (23) and a fourth chamber (24), an air supply module (5) for blowing air into the reaction tube section (3) is provided in each of the first chamber (21), the second chamber (22), the third chamber (23) and the fourth chamber (24), and an exhaust module (6) for exhausting air is provided in each of the first chamber (21), the second chamber (22), the third chamber (23) and the fourth chamber (24).

2. The device for achieving continuous atomic-level coating of powders according to claim 1, characterized in that: The reaction chamber (2) is detachably provided with a heating device (7) for heating the reaction chamber (2), and the heating device (7) is capable of separately regulating the temperatures of the first chamber (21), the second chamber (22), the third chamber (23), and the fourth chamber (24).

3. The device for achieving continuous atomic-level coating of powders according to claim 1, characterized in that: The gas supply module (5) of the first chamber (21) supplies a first precursor, the gas supply module (5) of the third chamber (23) supplies a second precursor, and the gas supply modules (5) of the second chamber (22) and the fourth chamber (24) supply an inert gas. The gas supply module (5) is provided with a plurality of nozzles (52).

4. The device for achieving continuous atomic-level coating of powders according to claim 1, characterized in that: The exhaust module (6) is a vacuum pump, and the first chamber (21), the second chamber (22), the third chamber (23) and the fourth chamber (24) are provided with independent vacuum pumps.

5. The device for achieving continuous atomic-level coating of powders according to claim 1, characterized in that: A spiral feeding device (33) is provided on the frame (1) at the feed port (31), and a cyclone separator (34) is provided on the frame (1) at the discharge port (32).

6. The device for achieving continuous atomic-level coating of powders according to claim 1, characterized in that: The reaction tube section (3) is tilted from the first chamber (21) to the fourth chamber (24), and tilted from top to bottom to achieve smooth discharge. The frame (1) is provided with a height adjustment device (8) for adjusting the tilt angle of the reaction tube section (3).

7. The device for achieving continuous atomic-level coating of powders according to claim 1, characterized in that: The pore size of the reaction tube section (3) is 100 mesh to 10000 mesh.

8. A method for implementing a device for achieving continuous atomic-level coating of powders as claimed in any one of claims 2 to 7, characterized in that: The following steps are involved: S1, the heating device (7) is preheated to the reaction temperature of the reaction chamber (2), the reaction tube section (3) rotates, and then the powder particles are input into the reaction tube section (3) and enter the first chamber (21), a first precursor for reaction is introduced into the first chamber (21), and the exhaust module (6) exhausts the gas to achieve the reaction of the powder particles in the first chamber (21); S2, after the powder particles react completely in the first chamber (21), the powder particles continuously move into the second chamber (22), a gas for cleaning is introduced into the second chamber (22), and the exhaust module (6) exhausts the gas, thereby achieving cleaning of the powder particles in the second chamber (22) and exhaust of excess first precursor; S3, after the cleaning is completed, the powder particles continuously move into the third chamber (23), a second precursor for reaction is introduced into the third chamber (23), and the exhaust module (6) exhausts the gas to achieve the reaction of the powder particles in the third chamber (23); S4, after the powder particles react completely in the third chamber (23), the powder particles continuously move into the fourth chamber (24), a gas for cleaning is introduced into the fourth chamber (24), and the exhaust module (6) exhausts the gas, thereby achieving cleaning of the powder particles in the fourth chamber (24) and exhaust of the excess second precursor; S5. After cleaning is completed, the powder particles are output.

9. The method for achieving continuous atomic-level coating of powders according to claim 8, characterized in that: When it is necessary to coat the powder particles for multiple cycles, the powder particles in step S5 can be output to the first chamber (21) for cyclic reaction, or a combination of the first chamber (21), the second chamber (22), the third chamber (23) and the fourth chamber (24) can be connected and arranged at the rear end of the fourth chamber (24) to achieve multi-cycle coating.

10. The method for achieving continuous atomic-level coating of powders according to claim 8, characterized in that: The cleaning gas introduced into the second chamber (22) or the fourth chamber (24) is nitrogen or argon.

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