A device and method for realizing continuous atomic-level coating of powder

Abstract

The present application relates to the technical field of atomic layer deposition, and particularly relates to a device and method for realizing continuous atomic-level coating of powder, the device for realizing continuous atomic-level coating of powder comprises a rack, reaction chambers arranged on the rack in a flow pipeline, a reaction tube segment transversely arranged through the reaction chambers, and a rotation driving device arranged on the rack and used for driving the reaction tube segment to rotate around an axis, the reaction tube segment is a porous structure capable of allowing air to pass through and preventing powder from running out, one end of the reaction tube segment is provided with a feeding port, and the other end is provided with a discharging port, the reaction chambers comprise a first chamber, a second chamber, a third chamber and a fourth chamber, the first chamber, the second chamber, the third chamber and the fourth chamber are provided with a gas supply module used for blowing air to the reaction tube segment, and the first chamber, the second chamber, the third chamber and the fourth chamber are provided with an exhaust module used for exhausting air. The device solves the technical problem that powder materials are difficult to realize efficient, continuous and controllable atomic-level coating.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of atomic layer deposition, and particularly relates to a device and method for realizing continuous atomic-level coating of powder. BACKGROUND

[0002] In the field of powder material surface treatment technology, surface coating modification of powder materials is an important means to improve their performance and expand their application range. By coating the surface of the powder material, the interface behavior and use performance of the powder can be significantly improved to meet the strict requirements of different application fields for the surface function of the material.

[0003] At present, the surface coating methods for powder materials mainly include physical vapor deposition (PVD), wet chemical coating, chemical vapor deposition (CVD), etc. Among them, PVD method can obtain relatively uniform thin film, but it is mostly carried out in high vacuum environment, with high cost and limited production capacity; the wet chemical coating method is simple in process and easy to scale up, but it has limitations in film uniformity and controllability; the conventional CVD technology can obtain thin film with high purity and density, but it is difficult to achieve atomic-level precise control of thickness.

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

[0005] However, the traditional thin film ALD process is mainly aimed at flat panels, thin films or bulk porous materials. For the coating of bulk powder, especially in continuous production scenarios, there are still many technical challenges. Traditional ALD processes mostly use intermittent reaction chambers for precursor alternating injection, adsorption and cleaning under static or low flow conditions, which is difficult to meet the needs of continuous flow coating of a large amount of powder. To realize high-yield, industrialized continuous production, it is necessary to maintain the continuous movement and efficient circulation of the powder in the reaction zone, and to ensure the strict isolation and precise alternation of different precursors, but the existing intermittent or batch ALD devices cannot overcome the above contradictions.

[0006] The spatial ALD (S-ALD) concept provides a new idea for solving the problem of continuousness, but the powder S-ALD schemes reported so far still have obvious deficiencies in process or device structure. For example, some schemes have the problems of serious precursor backmixing, too long device size, difficult processing and maintenance, low precursor utilization rate caused by high gas flow rate, and poor adaptability to gas / solid flow or single particle flow with high particle content.

[0007] In summary, there is an urgent need for a new method and equipment for continuous atomic layer deposition of powder to solve the key bottlenecks such as difficulty in realizing continuousness of the atomic layer deposition device, easy cross contamination of the precursor, and uneven coating caused by insufficient gas-solid contact in the prior art, to realize high-yield and high-uniformity atomic film deposition, and to meet the needs of industrial production. SUMMARY

[0008] Therefore, in view of the above problems, the present application provides a device for realizing continuous atomic-level coating of powder, which aims to overcome the deficiencies in the prior art and realize efficient, continuous and controllable atomic-level coating of powder materials through innovative design ideas and technical means, thereby providing strong support for the industrial application of powder materials in many fields. Based on this, a method for realizing continuous atomic-level coating of powder is also provided.

[0009] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0010] A device for realizing continuous atomic-level coating of powder comprises a rack, a reaction chamber arranged on the rack in a flow pipeline, a reaction tube segment transversely arranged through the reaction chamber, and a rotation driving device arranged on the rack for driving the reaction tube segment to rotate around an axis. The reaction tube segment is a porous structure that can transmit gas and block powder from running out. One end of the reaction tube segment is provided with a feeding port, and the other end is provided with a discharging port. The reaction chamber comprises a first chamber, a second chamber, a third chamber and a fourth chamber. The first chamber, the second chamber, the third chamber and the fourth chamber are respectively provided with a gas supply module for blowing gas to the reaction tube segment. The first chamber, the second chamber, the third chamber and the fourth chamber are provided with an exhaust module for exhaust.

[0011] Further, the reaction chamber is detachably provided with a heating device for heating the reaction chamber. The heating device can realize the separate regulation of the temperature of the first chamber, the second chamber, the third chamber and the fourth chamber.

[0012] Further, 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.

[0013] Further, 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.

[0014] Further, the reaction tube segments are arranged in a slope from the first chamber to the fourth chamber and from top to bottom, so as to realize smooth discharging, and the rack is provided with a height adjusting device for adjusting the slope angle of the reaction tube segments.

[0015] Further, the pore size of the reaction tube segments is 100-10000 mesh.

[0016] Based on the same inventive concept, a method applied to the device for realizing continuous atom-level coating of powder is also proposed, which comprises the following steps:

[0017] S1, the heating device is preheated to the reaction temperature of the reaction chamber, the reaction tube segment is rotated, then the powder particles are input into the reaction tube segment and enter the first chamber, the first precursor for reaction is introduced into the first chamber, and the exhaust module exhausts, so as to realize the reaction of the powder particles at the first chamber;

[0018] S2, after the powder particles are completely reacted at the first chamber, the powder particles continuously move into the second chamber, the gas for cleaning is introduced into the second chamber, and the exhaust module exhausts, so as to realize the cleaning of the powder particles at the second chamber and the discharge of the excess first precursor;

[0019] S3, after the cleaning is completed, the powder particles continuously move into the third chamber, the second precursor for reaction is introduced into the third chamber, and the exhaust module exhausts, so as to realize the reaction of the powder particles at the third chamber;

[0020] S4, after the powder particles are completely reacted at the third chamber, the powder particles continuously move into the fourth chamber, the gas for cleaning is introduced into the fourth chamber, and the exhaust module exhausts, so as to realize the cleaning of the powder particles at the fourth chamber and the discharge of the excess second precursor;

[0021] S5, after the cleaning is completed, the powder particles are output.

[0022] Further, when it is needed to coat the powder particles for multiple cycles, the powder particles of S5 are output to the first chamber for cyclic reaction, or the combination module formed by the same number of first chambers, second chambers, third chambers and fourth chambers as the number of coating cycles is connected and arranged at the rear end of the fourth chamber.

[0023] Further, the gas for cleaning introduced into the second chamber or the fourth chamber is nitrogen or argon.

[0024] By adopting the foregoing technical solutions, the application has the following beneficial effects:

[0025] 1. The present application realizes continuous feeding, processing and discharging of powder particles, greatly improving production efficiency. The rotation of the reaction tube section causes the powder particles to constantly turn during the reaction, 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 blocking the pores and further ensuring the continuity and stability of the coating process. The design of multiple reaction chambers allows different precursors and inert gases to act in independent spaces, avoiding cross-contamination and improving the utilization rate of precursors. Through the blowing of the airflow, the powder particles also form a spiral state in the reaction tube section. This spiral flow not only enhances the contact efficiency of the powder particles and the precursors, but also promotes the uniform dispersion of the particles, further improving the coating effect.

[0026] 2. According to the reaction requirements of different precursors, the temperature of each chamber can be independently adjusted to ensure that the reaction is carried out under optimal conditions. The detachable design of the heating device facilitates cleaning, maintenance and replacement in the later stage, reducing maintenance costs. Independent regulation of the temperature of each chamber helps to accurately control the reaction process and optimize the quality and performance of the coating layer.

[0027] 3. By independently distributing precursors and inert gases, cross-contamination between different precursors is avoided, ensuring the purity of the coating layer. The supply of inert gas in the second and fourth chambers effectively cleans the excess precursors and by-products on the surface of the powder particles, improving the coating quality. The specific distribution of the gas supply module design simplifies the operation process and improves production efficiency.

[0028] 4. The vacuum pump can quickly and effectively exhaust excess gas and by-products in the chamber, maintaining stable pressure in the chamber. Through independent vacuum pump systems, gas crosstalk between different chambers is avoided, ensuring the accuracy of the reaction. Stable chamber pressure and precise gas control help to improve coating efficiency and quality.

[0029] 5. The spiral feeding device realizes continuous and uniform feeding of powder particles, ensuring the continuity of production. The cyclone separator at the discharge port realizes gas-solid separation, efficiently collecting coated powder particles and recycling excess gas. The automation design of the feeding and discharging mechanism reduces manual intervention, improving production efficiency and product quality stability.

[0030] 6、The reaction tube segment arranged obliquely utilizes the action of gravity to ensure that the powder particles can continuously move through different reaction chambers and smoothly discharge after the reaction is completed. The setting of the height adjustment device allows the inclination angle of the reaction tube segment to be adjusted according to different atomic layer deposition process requirements, thereby optimizing the powder particle residence time, discharge speed and coating effect. By synergistically regulating the inclination angle and rotation speed of the reaction tube segment, the adjustability of the discharge speed and residence time can be ensured, so that the device can 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.

[0031] 7、The appropriate pore size not only ensures the permeability of the gas but also effectively blocks the powder particles from running out, thereby ensuring the smooth progress of the reaction. The selection of the pore size has an important influence on the uniformity and density of the coating layer, and appropriate pore size helps to improve the coating quality. In combination with the blowing force of different angles generated by rotation, moderate pore size can further reduce the risk of powder particles blocking the pores and improve the stability of the device operation.

[0032] 8、Through a continuous and automated operation process, efficient atomic-level coating of the powder particles is realized, and the production efficiency is improved. The reaction conditions (such as temperature, gas flow, reaction time, etc.) of each step are accurately controlled to ensure the controllability of the coating layer quality. During rotation, the gas flow blows the powder particles into a spiral state, enhancing the contact between the particles and the precursor and promoting uniform coating.

[0033] 9、Through cyclic reactions, multi-cycle coating of the powder particles is realized to meet the needs of different applications for the thickness of the coating layer. Multi-cycle coating helps to further improve the uniformity, density and performance of the coating layer, thereby widening the application range of the powder materials. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a structural schematic diagram of the present application.

[0035] Figure 2 is a cross-sectional structural schematic diagram of the reaction chamber.

[0036] Figure 3 is a graph showing the relationship between the actual film coating times of the powder particles and the film thickness.

[0037] Figure 4 is a structural schematic diagram of the first nozzle arrangement of the gas supply module.

[0038] Figure 5 is a structural schematic diagram of the second nozzle arrangement of the gas supply module.

[0039] Figure 6 is a transmission electron microscope image of Al2O3 particles coated with a silicon oxide film.

[0040] Reference signs:

[0041] 1, frame; 2, reaction chamber; 21, first chamber; 22, second chamber; 23, third chamber; 24, fourth chamber; 3, reaction tube segment; 31, feeding port; 32, discharging port; 33, screw feeding device; 34, cyclone separator; 4, rotating driving device; 5, gas supply module; 51, transverse moving driving mechanism; 52, nozzle; 6, exhaust module; 61, filtering mechanism; 7, heating device; 8, height adjusting device. DETAILED DESCRIPTION

[0042] The present application will be further described in conjunction with the drawings and specific embodiments.

[0043] Reference Figure 1 The embodiment provides a device for realizing continuous atom-level coating of powder, which comprises a frame 1, a reaction chamber 2 arranged on the frame 1 in a flow line, a reaction tube segment 3 transversely arranged through the reaction chamber 2, a rotating driving device 4 arranged on the frame 1 and used for driving the reaction tube segment 3 to rotate around an axis, the reaction tube segment 3 is a porous structure capable of allowing gas to pass through and preventing powder from running out, one end of the reaction tube segment 3 is provided with a feeding port 31, and the other end is provided with a discharging port 32, the reaction chamber 2 comprises a first chamber 21, a second chamber 22, a third chamber 23 and a fourth chamber 24, the first chamber 21, the second chamber 22, the third chamber 23 and the fourth chamber 24 are respectively provided with a gas supply module 5 used for blowing gas to the reaction tube segment 3, and the first chamber 21, the second chamber 22, the third chamber 23 and the fourth chamber 24 are provided with an exhaust module 6 used for exhausting.

[0044] The first chamber 21, the second chamber 22, the third chamber 23 and the fourth chamber 24 can not be in communication with each other, and only the reaction tube segment 3 is used to realize the passing of the powder particles, and an automatic isolation door (not shown in the figure, but those skilled in the art should understand the setting position and setting mode of the automatic isolation door) for sealing the powder particles into different chambers can also be arranged at the reaction tube segment 3, and the automatic isolation door can be an electromagnetic valve or a mechanical lifting door. The reaction tube segment 3 is made of a porous ceramic or a stainless steel filter screen, and can also be made of a metal fiber felt, a sintered metal porous material or other materials, and the pore size is 500 meshes (a preferred value, and the range is between 100 meshes and 10000 meshes), which can realize air permeability and effectively prevent the powder from running out. The feeding port 31 and the discharging port 32 are connected with the reaction tube segment 3 through mechanical sealing, so that the feeding port 31 and the discharging port 32 remain stationary when the reaction tube segment 3 rotates, for example, the mechanical sealing is connected through a rolling shaft, so that the reaction tube segment 3 rotates independently. A stepping motor or a servo motor is used as a rotating driving device 4, which is used in cooperation with a speed reducer to realize more accurate speed control, and the rotating speed of the reaction tube segment 3 can be adjusted in the range of 1 r / min-200 r / min. The combination of the first chamber 21, the second chamber 22, the third chamber 23 and the fourth chamber 24 can be repeatedly arranged, so as to realize multi-cycle reaction.

[0045] The reaction chamber 2 is detachably provided with a heating device 7 for heating the reaction chamber 2, and the heating device 7 can realize the independent adjustment of the temperature 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, and the heating mode can also be replaced by microwave heating or electromagnetic induction heating to improve the heating efficiency and temperature uniformity. The heating device 7 is connected with the reaction chamber 2 through mechanical sealing, and the detachable design is convenient for later cleaning and maintenance. The heating device 7 is divided into four independent control temperature zones, which correspond to the first chamber 21, the second chamber 22, the third chamber 23 and the fourth chamber 24 respectively, and the temperature of each temperature zone can be independently adjusted, and the adjustment range is 20℃-400℃.

[0046] 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 module 5 of the second chamber 22 and the fourth chamber 24 supplies an inert gas. The first precursor and the second precursor can be selected according to actual needs, and the inert gas can be nitrogen, argon or helium, as long as it does not chemically react with the first precursor, the second precursor and the powder particles. The flow and speed of the inert gas can also be selected according to actual needs.

[0047] 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 by other forms of exhaust devices, such as a fan or an exhaust fan, as long as it can effectively exhaust the gas in the chamber. The second chamber 22 and the fourth chamber 24 can also share a vacuum pump. The gas exhausted from the first chamber 21, the second chamber 22, the third chamber 23 and the fourth chamber 24 can be recycled after treatment. A filtering mechanism 61 is provided at the exhaust module 6, and the aperture of the filtering mechanism 61 should be smaller than the aperture of the reaction tube segment 3.

[0048] A spiral feeding device 33 is provided on the rack 1 at the inlet 31, and a cyclone separator 34 is provided on the rack 1 at the outlet 32. The spiral feeding device 33 and the cyclone separator 34 are both conventional devices in the field, and other similar functional devices can also be used instead.

[0049] The reaction tube segment 3 is inclined from the first chamber 21 to the fourth chamber 24, and is inclined from top to bottom to achieve smooth discharge. A height adjusting device 8 for adjusting the inclination angle of the reaction tube segment 3 is provided on the rack 1. The height adjusting device 8 can be a combination of one or more of a connecting rod mechanism, a gas cylinder, an oil cylinder and an electric push rod.

[0050] A method for realizing continuous atomic-level coating of powder, comprising the following steps:

[0051] S1, the heating device 7 is preheated to the reaction temperature of the reaction chamber 2, the reaction tube segment 3 is rotated, and then the powder particles are input into the reaction tube segment 3 and enter the first chamber 21, the first chamber 21 is supplied with the first precursor for reaction, and the exhaust module 6 exhausts to realize the reaction of the powder particles at the first chamber 21;

[0052] S2, after the powder particles are completely reacted at the first chamber 21, the powder particles continuously move into the second chamber 22, the second chamber 22 is supplied with a gas for cleaning, and the exhaust module 6 exhausts to realize the cleaning of the powder particles located at the second chamber 22 and the discharge of excess first precursor;

[0053] S3, after the cleaning is completed, the powder particles continuously move into the third chamber 23, the third chamber 23 is supplied with the second precursor for reaction, and the exhaust module 6 exhausts to realize the reaction of the powder particles at the third chamber 23;

[0054] S4, after the powder particles are completely reacted at the third chamber 23, the powder particles continuously move into the fourth chamber 24, the fourth chamber 24 is supplied with a gas for cleaning, and the exhaust module 6 exhausts to realize the cleaning of the powder particles located at the fourth chamber 24 and the discharge of excess second precursor;

[0055] S5, after cleaning, the powder particles are output.

[0056] When multi-cycle coating of the powder particles is needed, the powder particles of S5 are output to the first chamber 21 for cyclic reaction. That is, the powder particles of S5 are output to S1 for cyclic reaction until the reaction cycle is reached, and then output. Alternatively, a combination of the first chamber 21, the second chamber 22, the third chamber 23 and the fourth chamber 24 is arranged after the fourth chamber 24, so as to realize multi-cycle coating. The combination of the first chamber 21, the second chamber 22, the third chamber 23 and the fourth chamber 24 can be multiple, that is, several cycles of coating are needed, and several combinations are arranged. In actual application, the more the number of cyclic reactions, the thicker the thickness of the coating film, as shown in the figure, which is a graph showing the relationship between the actual number of coating films of a certain powder particle and the thickness of the film. Figure 3

[0057] In addition, for multi-cycle coating, the combination of the first chamber 21, the second chamber 22, the third chamber 23 and the fourth chamber 24 is increased, and by selecting different combinations of precursors, mixed deposition of different films can also be realized, thereby forming a hybrid functional film.

[0058] The gas 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 requirements. The structure of the nozzles can be flat or circular, and the nozzles 52 can be arranged on a plane or an arc surface, as shown in Figure 4 Figure 5 of course, other arrangements can also be used. In order to better gas-solid contact and higher efficiency of precursor utilization, the nozzles 52 can be arranged in a single row or in an array. The purpose is to blow the powder particles in the reaction tube section, so as to realize the tumbling of the powder particles, so that the powder particles can react more fully. The structure and arrangement of the gas supply module 5 can be adjusted according to actual needs, and the purpose is to realize the blowing of the powder particles in the reaction tube section 3, so as to realize the rotation of the powder particles, and realize better and more uniform reaction.

[0059] Referring to Figure 2 , which is a cross-sectional structure diagram of the reaction chamber 2, the reaction tube section 3 rotates counterclockwise, and the powder particles in the reaction tube section 3 form a clockwise rotating state. The gas supply module 5 is not located directly below the reaction tube section 3, but is offset from the center by a distance L, and the inner diameter of the reaction tube section 3 is r, which satisfies L / r = 0.7 to 0.8.

[0060] ​​As the reaction tube segment 3 rotates counterclockwise and the powder particles rotate clockwise, the rotation directions of the two are opposite, which forms a complex spiral flow inside the reaction tube segment 3. This spiral flow can significantly enhance the contact between the powder particles and the precursor gas, improving the gas-solid reaction efficiency.

[0061] The offset design of the gas supply module 5 from the center of the reaction tube segment 3 forms a clockwise air flow and also forms a local turbulent flow, further increasing the contact opportunities between the powder particles and the precursor gas, which helps to improve the uniformity and density of the coating layer.

[0062] The combined action of spiral flow and local turbulent flow makes the powder particles more uniformly coated inside the reaction tube segment 3, reducing the non-uniformity 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 the coating efficiency and shortening the production cycle.

[0063] The combination of clockwise rotation of the powder particles and counterclockwise rotation of the reaction tube segment 3 forms a dynamic unblocking mechanism. This mechanism helps to reduce the blockage of the powder particles in the pores of the reaction tube segment 3, maintaining the air permeability of the reaction tube segment 3. The offset design of the gas supply module 5 makes the air flow distribution inside the reaction tube segment 3 more uniform, reducing the risk of blockage caused by excessive or insufficient local air flow.

[0064] The ratio of L / r is between 0.7 and 0.8, which is a relatively optimized range. This ratio can be adjusted according to actual production needs to adapt to powder particles of different particle sizes and densities, as well as the reaction characteristics of different precursor gases. This design enables the device to adapt to a wider range of production conditions, improving the flexibility and adaptability of the device.

[0065] In addition, a horizontal movement driving mechanism 51, such as a lead screw mechanism, can be installed to move the gas supply module 5, thereby changing the value of L and adjusting the blowing effect of the air flow. The part of the gas supply module 5 in the reaction chamber 2 is a gas supply box.

[0066] In actual application, the gas supply module 5 shown in the figure is used, which can cooperate with the circular tube-shaped reaction tube segment 3 to achieve a better air flow blowing effect. Figure 5

[0067] The scheme realizes continuous atomic-level coating of powder particles, which has the following advantages compared to batch processes:

[0068] 1. Increased production capacity: Continuous processes can at least increase production capacity by tens of times per unit time compared to batch processes, and even up to thousands of times in industrial systems.

[0069] ​2. Process stability: Maintain coating quality comparable to small-scale batch processing systems while meeting the needs of mass production;

[0070] 3. Extremely high consistency: Continuous processes can achieve a high degree of consistency in coating quality, thereby avoiding the problem of inconsistent coating quality between batches in intermittent processes.

[0071] This demonstrates that the continuous ALD process for powder particles exhibits an overwhelming advantage in production efficiency during large-scale industrial production.

[0072] Taking the continuous deposition of SiO2 thin films on the surface of Al2O3 particles as an example:

[0073] The porous reaction tube section 3 has an inner diameter of 10 cm and a pore size of 300 mesh. Al2O3 nanoparticles with an average particle size of 250 mesh (approximately 60 μm) were selected as the substrate, with silicon tetrachloride (SiCl4) as the first precursor and deionized water (H2O) as the second precursor. The cleaning gas used is 99.999% high-purity nitrogen. The gas supply flow rate for the first chamber 21 is set to 3 L / min, and the temperature is set to 150℃. The gas supply flow rate for the second chamber 22 is set to 3 L / min, and the temperature is set to 150℃. The gas supply flow rates for the second chamber 22 and the fourth chamber 24 are set to 5 L / min, and the temperature is set to 150℃ for both. Al2O3 particles are continuously fed into the feed inlet 31 through the screw feeder 33 at a rate of 100 g / min. The inclination angle of the reaction tube section 3 is set to 5°, and the rotation speed of the reaction tube section 3 is set to 40 r / min to ensure that the particles maintain uniform dispersion and high gas-solid contact efficiency while passing through the first chamber 21 to the fourth chamber 24 sequentially. After the particles are collected from the tail end of the fourth chamber 24, the collected powder is returned to the feed inlet 31. Repeating the above steps 20 times can achieve continuous coating of Al2O3 particles for 20 cycles.

[0074] like Figure 6 As shown, it is a transmission electron microscope (TEM) image of Al2O3 particles coated with a silicon oxide film. The TEM characterization image shows that after 20 consecutive atomic layer deposition coating cycles, a uniform and dense silicon oxide film grows on the surface of Al2O3 particles, exhibiting high conformation.

[0075] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which shall be within the scope of protection of the invention.

Claims

1. An apparatus for realizing continuous atomic level coating of powders, characterized in that: The utility model relates to a kind of reaction tube segment and reaction chamber for preparing powder, including rack (1) and reaction chamber (2) being arranged in rack (1) according to flow pipeline, reaction tube segment (3) being crossed through reaction chamber (2), rotating drive device (4) being arranged in rack (1) for driving reaction tube segment (3) rotation around shaft, the reaction tube segment (3) is porous structure that can be breathable and blocks powder to run out, the reaction tube segment (3) is provided with feed inlet (31) in one end, and discharge outlet (32) is provided with in other end, the reaction chamber (2) includes first chamber (21), second chamber (22), third chamber (23) and fourth chamber (24), the first chamber (21), second chamber (22), third chamber (23) and fourth chamber (24) are provided with gas supply module (5) for blowing gas to reaction tube segment (3) respectively, the first chamber (21), second chamber (22), third chamber (23) and fourth chamber (24) are provided with exhaust module (6) for carrying out exhaust. The reaction chamber (2) is detachably provided with a heating device (7) for heating, and the heating device (7) can realize the separate regulation of the temperature of the first chamber (21), the second chamber (22), the third chamber (23) and the fourth chamber (24). 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 inert gas. The reaction tube segment (3) is inclined from the first chamber (21) to the fourth chamber (24), and is inclined from top to bottom to realize smooth discharge.

2. The device for realizing continuous atomic level coating of powder 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.

3. The device for realizing continuous atomic level coating of powder according to claim 1, characterized in that: The rack (1) is provided with a spiral feeding device (33) at the feed inlet (31), and is provided with a cyclone separator (34) at the discharge outlet (32).

4. The device for realizing continuous atomic level coating of powder according to claim 1, characterized in that: The pore size of the reaction tube segment (3) is 100-10,000 mesh.

5. A method for using the device for realizing continuous atomic level coating of powder as claimed in any one of claims 2 to 4, characterized in that, The utility model relates to a kind of reaction tube segment and reaction chamber for preparing powder, including the following steps: S1, the heating device (7) is preheated to the reaction temperature of reaction chamber (2), the reaction tube segment (3) rotates, and then powder particles are input into the reaction tube segment (3), enter the first chamber (21), the first chamber (21) is connected with the first precursor for reaction, and the exhaust module (6) exhausts, realizes the reaction of powder particles at the first chamber (21); S2, after powder particles are completely reacted at the first chamber (21), powder particles continuously move into the second chamber (22), the second chamber (22) is connected with the gas for cleaning, and the exhaust module (6) exhausts, realizes the cleaning of powder particles at the second chamber (22) and the discharge of excess first precursor; S3, after cleaning, the powder particles continuously move into the third chamber (23), the second precursor for reaction is introduced into the third chamber (23), and the exhaust module (6) exhausts to realize the reaction of the powder particles at the third chamber (23); S4, after the powder particles are completely reacted at the third chamber (23), the powder particles continuously move into the fourth chamber (24), the gas for cleaning is introduced into the fourth chamber (24), and the exhaust module (6) exhausts to realize the cleaning of the powder particles located at the fourth chamber (24) and the discharge of the excess second precursor; S5, after cleaning, the powder particles are output.

6. The method of claim 5, wherein: When multi-cycle coating of the powder particles is needed, the powder particles of S5 can be output to the first chamber (21) for cyclic reaction, or the combination of the first chamber (21), the second chamber (22), the third chamber (23) and the fourth chamber (24) formed after the fourth chamber (24) is continuously connected and arranged at the rear end, so that multi-cycle coating is realized.

7. The method of claim 5, wherein: The gas for cleaning introduced into the second chamber (22) or the fourth chamber (24) is nitrogen or argon.

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