Continuous chemical vapor deposition system

Abstract

The utility model discloses a continuous chemical vapor deposition system, which relates to the field of silicon carbon production and manufacturing equipment, and comprises a deposition unit, a chemical vapor deposition unit and a control unit, the deposition unit comprises a deposition furnace and a buffer furnace, and the feed end of the buffer furnace is communicated with the discharge end of the deposition furnace; the feeding unit is communicated with the feeding end of the deposition furnace; the detection unit is communicated with the discharge end of the buffer furnace, and is used for carrying out gas-solid separation on materials in the buffer furnace, carrying out automatic detection on gas and carrying out automatic sampling on solids; the coating unit comprises a coating furnace and a coating gas inlet pipeline, and the solid material subjected to gas-solid separation treatment is introduced into the coating furnace; and the material receiving unit is communicated with the discharging end of the cladding furnace. According to the continuous system, conveying of materials among different working procedures can be reduced, the technology is automatically adjusted, the production efficiency is greatly improved, and the requirement for large-scale production is met.

Description

Technical Field

[0001] This utility model relates to equipment for manufacturing silicon-carbon anode materials, and more particularly to a continuous chemical vapor deposition system. Background Technology

[0002] With the rapid development of the new energy industry, society's expectations for the energy density of lithium-ion batteries are further increasing, making the research and development of high-energy-density anode battery materials an urgent priority. Currently, commercially available graphite anode materials are approaching their theoretical specific capacity limit (372 mAh / g). To further improve battery energy density, finding anode materials with even higher specific capacity has become a key focus of industry research. Silicon, when alloyed with lithium at room temperature, has a theoretical specific capacity as high as 4200 mAh / g, more than ten times that of current graphite-based anode materials. It does not have the risk of lithium plating, has better safety than graphite-based anode materials, and is abundant and inexpensive, making it the most promising next-generation lithium battery anode material.

[0003] Silane composite active materials combine the advantages of both silicon and carbon materials, with widely available raw materials, resulting in superior performance. In the preparation of silicon-carbon materials, chemical vapor deposition (CVD) is the mainstream technology due to its low cost and mature technology.

[0004] Currently, the CVD method for preparing silicon-carbon anode materials mainly employs a batch system, meaning that only a small batch of materials is prepared at a time, and the next batch is prepared only after the previous batch is completed. While this batch method is simple, it is inefficient and cannot meet the needs of large-scale production. Furthermore, the CVD process requires the use of hazardous gases such as acetylene, methane, and hydrogen; if the sealing is inadequate, explosions can easily occur, causing injury to workers. Secondly, the temperature control of existing CVD furnaces is not precise enough, failing to ensure sufficient mixing of silane and carbon, thus affecting the quality of the prepared silicon-carbon materials.

[0005] In view of this, this utility model is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a continuous chemical vapor deposition system that can reduce the material transport between different processes, greatly improve the production efficiency of CVD preparation, and meet the needs of large-scale production.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] This invention proposes a continuous chemical vapor deposition system, comprising at least:

[0009] A deposition unit includes a deposition furnace and a buffer furnace, wherein the feed end of the buffer furnace is connected to the discharge end of the deposition furnace;

[0010] The feeding unit is connected to both ends of the deposition furnace;

[0011] The detection unit, connected to the discharge end of the buffer furnace, performs gas-solid separation on the material in the buffer furnace, automatically detects the gas, and automatically samples the solid; and

[0012] The coating unit includes a coating furnace and a coating inlet pipe, wherein the coating furnace introduces solid material that has undergone gas-solid separation treatment.

[0013] In one embodiment of the present invention, the deposition furnace and / or buffer furnace is columnar, and the length-to-diameter ratio of the deposition furnace and / or buffer furnace is 5-15:1;

[0014] And / or, the deposition furnace and / or buffer furnace includes a furnace body and an outer shell, the outer shell being fitted onto the furnace body;

[0015] And / or, an insulation layer is provided between the furnace body and the outer shell, and a plurality of heating components are provided within the insulation layer;

[0016] And / or, the inner wall of the furnace body is provided with a plurality of guide plates, which are evenly distributed along the axial direction of the furnace body;

[0017] The deposition furnace and / or buffer furnace are mounted on a support, and the support drives the deposition furnace and / or buffer furnace to rotate, with the buffer furnace rotating at a higher speed than the deposition furnace.

[0018] In one embodiment of the present invention, the detection unit includes a first gas-solid separator, which performs gas-solid separation on the material of the buffer furnace, with gas being discharged from a gas separation pipe and solid being discharged from a solid separation pipe.

[0019] Preferably, a filter membrane is provided on the inner wall of the first gas-solid separator, and the filter membrane is located at the connection between the first gas-solid separator and the gas separation pipe;

[0020] Preferably, the first gas-solid separator is a cyclone separator.

[0021] In one embodiment of this utility model, the detection unit further includes a main controller and a gas detector. The gas-solid separator is connected to the gas detector through a gas separation branch pipe to automatically detect the separated gas.

[0022] The main controller is electrically connected to the gas detector and controls the gas detector to perform automatic detection.

[0023] In one embodiment of this utility model, the detection unit further includes a material collection bin, and the gas-solid separator is connected to the material collection bin via a solid separation branch pipe;

[0024] A material sampling valve is installed on the solid separation branch pipeline, and the main controller is electrically connected to the material sampling valve to control the automatic sampling of the material sampling bin.

[0025] In one embodiment of the present invention, the feeding unit includes a porous carbon feeding device and a gas transmission device. The porous carbon feeding device is connected to the feeding end of the deposition furnace, and the gas transmission device is connected to the discharging end of the deposition furnace.

[0026] And / or, the porous carbon feeding device includes a feed bin and a feed pipe, the feed pipe extending into the interior of the deposition furnace;

[0027] And / or, the gas transmission device includes an intake pipe and an intake valve, through which the gas flow rate in the intake pipe is regulated;

[0028] And / or, the air intake pipe includes a first air intake pipe, a second air intake pipe and a third air intake pipe, the first air intake pipe and the second air intake pipe are connected in parallel to the gas mixer, and the gas mixer is connected to the deposition furnace through the third air intake pipe;

[0029] And / or, a preheater and a first intake valve are provided on the first intake pipe, wherein the preheater controls the gas temperature in the first intake pipe at 150-250°C.

[0030] And / or, a second intake valve is provided on the second intake pipe;

[0031] And / or, a third intake valve is provided on the third intake pipe.

[0032] In one embodiment of this utility model, the main controller is electrically connected to the first intake valve and controls the first intake valve to automatically close.

[0033] In one embodiment of the present invention, the detection unit further includes a gas alarm, which is disposed at the discharge end of the buffer furnace and is electrically connected to the first inlet valve.

[0034] When the gas alarm sounds, it controls the first air intake valve to close automatically.

[0035] In one embodiment of this utility model, a covered air intake valve is provided on the covered air intake pipe, and the main controller is electrically connected to the covered air intake valve to control the automatic opening and closing of the covered air intake valve.

[0036] In one embodiment of the present invention, the system further includes a material receiving unit, which is connected to the discharge end of the coating furnace; the material receiving unit includes a second gas-solid separator, which performs gas-solid separation on the material of the coating furnace, the separated gas is transported to the tail gas treatment device, and the separated solid material is transported to the transfer warehouse;

[0037] Preferably, the second gas-solid separator is a cyclone separator;

[0038] And / or, the transfer chamber is provided with a hollow interlayer, and a circulating water cooling coil is installed in the hollow interlayer to cool the materials in the transfer chamber.

[0039] In one embodiment of this utility model, the main controller controls the gas detector to detect the silicon source gas content every 10 minutes. When the detected silicon source gas content is <0.2mg / L, the controller controls the coating gas inlet valve to open and introduce coating gas into the coating furnace; the controller also controls the material taking valve to open and the material taking hopper to automatically take samples.

[0040] When the silicon source gas content detected by the gas detector is ≥0.2mg / L, the main controller controls the coating inlet valve and the material taking valve to close, and controls the first inlet valve to close.

[0041] In summary, the beneficial technical effects of this utility model are as follows:

[0042] 1. This system is a continuous preparation system, which can reduce the material transportation links between different processes, thereby reducing material loss and the introduction of external impurities, ultimately improving production efficiency and meeting the needs of large-scale production.

[0043] 2. Using a buffer furnace to further deposit unreacted silicon source gas improves raw material utilization and silicon deposition, and also avoids unreacted silicon source gas from affecting subsequent processes.

[0044] 3. Utilizing a gas-solid separator, gas detector, and main controller, the content of undecomposed silicon source is automatically detected. Once the threshold is exceeded, the silicon source supply is cut off, effectively preventing silicon source leakage. Simultaneously, real-time sampling of materials can be achieved, allowing for the detection of material deposition status and quality. Based on the structure, the process can be adjusted promptly to improve the electrochemical performance of the silicon-carbon anode material.

[0045] 4. Install a silicon source gas alarm. When the silicon source gas content in the nearby environment exceeds the standard, an alarm will be sounded and the input of silicon source gas will be cut off to prevent silicon source gas leakage from causing explosions and harm to the human body, thereby improving production safety. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0047] Figure 1 This is a schematic diagram of the overall structure of a continuous chemical vapor deposition system according to an embodiment of the present invention;

[0048] Figure 2 This is a schematic diagram of the structure of the feeding unit according to an embodiment of the present invention;

[0049] Figure 3 This is a schematic diagram of the structure of a deposition unit according to an embodiment of the present invention;

[0050] Figure 4 This is a schematic diagram of the deposition unit according to another embodiment of the present invention;

[0051] Figure 5 This is a schematic diagram of the detection unit and the coating unit according to an embodiment of the present invention;

[0052] Figure 6 This is a schematic diagram of the receiving unit according to an embodiment of the present utility model.

[0053] Label Explanation:

[0054] 1. Feeding unit; 11. Porous carbon feeding device; 111. Feeding bin; 112. Feeding pipe; 12. Gas transmission device; 121. First air inlet pipe; 122. First air inlet valve; 123. Preheater; 124. Second air inlet pipe; 125. Second air inlet valve; 126. Gas mixer; 127. Third air inlet pipe; 128. Third air inlet valve;

[0055] 2. Deposition unit; 21. Deposition furnace; 211. Furnace body; 212. Outer shell; 213. Insulation jacket; 214. Heating assembly; 215. Guide plate; 22. Buffer furnace; 23. Support frame; 231. Support arm;

[0056] 3. Detection unit; 31. First gas-solid separator; 311. Gas separation pipeline; 3111. Gas separation branch pipeline; 312. Solid separation pipeline; 3121. Solid separation branch pipeline; 313. Feed bin; 314. Feed valve; 315. Filter membrane; 32. Gas detector; 321. Gas detection valve; 33. Main controller; 34. Gas alarm;

[0057] 4. Coating unit; 41. Coating furnace; 42. Coating inlet pipe; 43. Coating inlet valve;

[0058] 5. Receiving unit; 51. Second gas-solid separator; 52. Transfer silo; 521. Hollow jacket; 53. Tail gas treatment device; 54. Circulating water cooling coil; 55. Receiving pipeline. Detailed Implementation

[0059] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0060] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0061] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the present invention. However, it will be apparent to those skilled in the art that embodiments of the present invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the present invention.

[0062] The present invention will now be described in further detail with reference to the accompanying drawings.

[0063] Please see Figure 1As shown, this application proposes a continuous chemical vapor deposition system, including a feeding unit 1, a deposition unit 2, a detection unit 3, a coating unit 4, and a receiving unit 5. The deposition unit 2 includes a deposition furnace 21 and a buffer furnace 22. The feeding unit 1 is connected to both ends of the deposition furnace 21, feeding material into the furnace. The discharge end of the deposition furnace 21 is connected to the feed end of the buffer furnace 22. The buffer furnace 22 utilizes the incompletely reacted silicon source gas in the deposition furnace 21 for further deposition, ensuring complete reaction of the silicon source gas and reducing floating silicon on the surface of the material to be coated later. The detection unit 3 is connected to the discharge end of the buffer furnace 22, performing gas-solid separation on the material in the buffer furnace 22, automatically detecting the separated gas, automatically sampling the separated solid, and simultaneously introducing the separated solid material into the coating unit 4. The coating unit 4 includes a coating furnace 41 and a coating inlet pipe 42. The outlet end of the coating furnace 41 is connected to the receiving unit 5. After the material introduced into the coating furnace 41 is carbon coated, it is transported to the receiving unit 5 for collection. The continuous chemical vapor deposition system of this invention can greatly improve the production efficiency of silicon-carbon anode materials, meet the needs of large-scale production, and allow for real-time monitoring of the deposited material and adjustment of the deposition process parameters, thereby improving the production quality of silicon-carbon anode materials.

[0064] Please see Figure 1 and Figure 2 As shown, in one embodiment of this utility model, the feeding unit 1 includes a porous carbon feeding device 11 and a gas transmission device 12. The porous carbon feeding device 11 and the gas transmission device 12 are respectively disposed at both ends of the deposition unit 2. Specifically, the porous carbon feeding device 11 is connected to the feed end of the deposition unit 2, and the gas transmission device 12 is connected to the discharge end of the deposition unit 2. By reverse ventilation, the material lifting effect can be further enhanced, thereby enabling the porous carbon to be fully deposited. The porous carbon feeding device 11 includes a feeding bin 111 and a feeding pipe 112. The bottom of the feeding bin 111 is connected to the deposition furnace 21 through the feeding pipe 112, and the feeding pipe 112 extends into the interior of the deposition furnace 21. The feeding pipe 112 can be inclined at a certain angle with the horizontal direction of the deposition furnace 21, and the inclination angle can be 0-60°. The material can be transported by gravity, and the feeding rate is, for example, 10-500 g / min.

[0065] Please see Figure 1 and Figure 2As shown, in one embodiment of this utility model, the gas transmission device 12 includes an inlet pipe and an inlet valve. In this embodiment, the inlet pipe includes a first inlet pipe 121, a second inlet pipe 124, and a third inlet pipe 127. The first inlet pipe 121 and the second inlet pipe 124 are connected in parallel to a gas mixer 126. The gas mixer 126 is connected to a deposition furnace 21 through the third inlet pipe 127, supplying mixed gas to the deposition furnace 21. A first inlet valve 122, a second inlet valve 125, and a third inlet valve 128 are respectively installed on the first inlet pipe 121, the second inlet pipe 124, and the third inlet pipe 127 to regulate the flow rate of the gas in the inlet pipe, and to adjust the flow rate of the gas in the inlet pipe to 0.1-10 L / min. The first inlet valve 122 is an automatic control valve.

[0066] Please see Figure 1 and Figure 2 As shown, in one embodiment of this invention, different gases are introduced into the first intake pipe 121 and the second intake pipe 124. A silicon source gas is introduced into the first intake pipe 121, and an inert gas is introduced into the second intake pipe 124. The silicon source gas is, for example, one or more of silane, dichlorosilane, dichlorosilane, and trichlorosilane, and the inert gas is, for example, one or more of nitrogen, argon, neon, krypton, xenon, or radon. After the silicon source gas and the inert gas are mixed by the gas mixer 126, the volume percentage of the silicon source gas in the mixed gas is 70-99 vol%, and the volume percentage of the inert gas in the mixed gas is 1-30 vol%. In another embodiment of this invention, a preheater 123 can also be installed on the first intake pipe 121. The preheater 123 is located between the first intake valve 122 and the gas mixer 126, heating the silicon source gas in the first intake pipe 121 to 150-250°C.

[0067] Please see Figures 1 to 3 As shown, the deposition unit 2 includes a deposition furnace 21, a buffer furnace 22, and a support 23. The discharge end of the deposition furnace 21 is connected to the feed end of the buffer furnace 22. The buffer furnace 22 utilizes the incompletely reacted silicon source gas in the deposition furnace 21 for further deposition, ensuring complete reaction of the silicon source gas and reducing floating silicon on the surface of the material to be coated later. The deposition furnace 21 and the buffer furnace 22 are mounted on the support 23, which drives the deposition furnace 21 and the buffer furnace 22 to rotate along its axis, with the buffer furnace 22 rotating at a higher speed than the deposition furnace 21. The deposition furnace 21 and the buffer furnace 22 have the same structure. This invention uses the deposition furnace 21 as an example to further illustrate its specific structure.

[0068] Please see Figures 1 to 3As shown, in one embodiment of this utility model, the deposition furnace 21 is generally cylindrical, and the length-to-diameter ratio of the deposition furnace 21 is 5-15:1. The deposition furnace 21 includes a furnace body 211 and an outer shell 212. The outer shell 212 is fitted onto the furnace body 211 and is mounted on a support 23. The support 23 includes support arms 231, which are located at both ends of the deposition furnace 21 and support the furnace body 211. A driving device (not shown in the figure) is mounted on the support arms 231 to drive the furnace body 211 to rotate along its axis. The inner wall of the furnace body 211 is provided with multiple guide plates 215, for example, 2-50 in number. The guide plates 215 are evenly distributed along the axial direction of the furnace body 211. Under the rotation of the furnace body 211 and the action of the guide plates 215, the material inside the furnace body 211 is propelled forward.

[0069] Please see Figures 1 to 3 As shown, in one embodiment of this utility model, a heat-insulating layer 213 exists between the furnace body 211 and the outer shell 212. A heating component 214 is disposed within the heat-insulating layer 213, and the heating component 214 is arranged around the inner wall of the outer shell 212. The heating component 214 heats the furnace body 211, which can heat the furnace body 211 to 100-1000℃. The heating component 214 can heat the entire furnace body 211 to a uniform temperature, or it can perform gradient heating of the entire furnace body 211, thus setting the furnace body 211 into multiple temperature zones. In another embodiment of this utility model, the heating component 214 sets the furnace body 211 into three temperature zones: a preheating zone 2111, a low-temperature zone 2112, and a high-temperature zone 2113. The temperature of the preheating zone 2111 is, for example, 100-250°C, the temperature of the low-temperature zone 2112 is, for example, 300-500°C, and the temperature of the high-temperature zone 2115 is, for example, 500-800°C. The material is preheated in the preheating zone 2111, gas adsorption occurs in the low-temperature zone 2112, and nano-silicon deposition occurs in the high-temperature zone 2115, thereby improving the deposition effect of porous carbon materials.

[0070] Please see Figures 1 to 4As shown, this invention does not limit the number of deposition furnaces 21. The number of deposition furnaces 21 can be one or more, and multiple deposition furnaces 21 can be connected in series and / or in parallel. In another embodiment of this invention, the number of deposition furnaces 21 is, for example, two, and the two deposition furnaces 21 are connected in series to a buffer furnace 22. Each deposition furnace 21 is supplied with silicon source gas, and the content of silicon source gas supplied to the downstream deposition furnace 21 is 50-90% of the content of silicon source gas supplied to the upstream deposition furnace 21, enabling segmented deposition. Furthermore, the temperature of the upstream deposition furnace 21 can be set to 300-500℃, and the temperature of the downstream deposition furnace 21 can be set to 500-800℃, further improving the effect of segmented deposition. Porous carbon materials have abundant pores. In the front-end deposition furnace 21, the temperature is low and the silicon source gas content is high. Due to their strong adsorption, the small pores in the porous carbon materials undergo adsorption deposition first. In the back-end deposition furnace 21, the temperature is high and the silicon source gas content is low. The remaining mesopores and macropores of the porous carbon materials begin adsorption deposition. Segmented deposition is beneficial to improving the pore utilization rate of porous carbon materials and increasing the amount of silicon deposited.

[0071] Please see Figures 1 to 5 As shown, in one embodiment of this invention, the detection unit 3 is connected to the discharge end of the buffer furnace 22, performing gas-solid separation on the material in the buffer furnace 22, and automatically detecting the gas and sampling the solid. If the silicon source gas content in the exhaust gas from the buffer furnace 22 is too high, it indicates that the silicon source gas has not reacted completely or is excessive, leading to poor deposition or material waste. Furthermore, excessive silicon source gas entering the coating unit 4 will compete with the coating gas, affecting the coating effect. Simultaneously, silicon source gas deposition in the coating unit 4 can cause floating silicon on the material surface, thus affecting the electrochemical performance of the silicon-carbon anode material. This invention sets up a detection unit 3 between the buffer furnace 22 and the coating unit 4, which can detect the silicon source gas content in the exhaust gas in real time, facilitating timely adjustment of process parameters, improving silicon source gas utilization, and enhancing deposition quality. Simultaneously, it can automatically sample the deposited material, allowing for real-time monitoring of the material's performance, thereby optimizing the deposition process.

[0072] Please see Figures 1 to 5 As shown, in one embodiment of this utility model, the detection unit 3 includes a first gas-solid separator 31, a gas detector 32, a main controller 33, and a gas alarm 34. The main controller 33 is electrically connected to the first gas-solid separator 31 and the gas detector 32 respectively, so as to realize automatic detection of gas and sampling of solid.

[0073] Please see Figures 1 to 5As shown, the first gas-solid separator 31 performs gas-solid separation on the material in the buffer furnace 22. The separated gas is transported to the tail gas treatment device (not shown in the figure) via the gas separation pipe 311, and the separated solid is transported to the coating unit 4 for coating via the solid separation pipe 312. The first gas-solid separator 31 is connected to the gas detector 32 via the gas separation branch pipe 3111, and a gas detection valve 321 is installed on the gas separation branch pipe 3111. The gas detection valve 321 is electrically connected to the main controller 33, which controls the automatic opening and closing of the gas detection valve 321. The gas detector 32 detects the silicon source gas content in the tail gas every 10 minutes. The first gas-solid separator 31 is connected to the feeding bin 313 via the solid separation branch pipe 3121, and a feeding valve 314 is installed on the solid separation branch pipe 3121. The feeding valve 314 is electrically connected to the main controller 33, which controls the automatic opening and closing of the feeding valve 314, enabling automatic sampling in the feeding bin 313. The main controller 33 is electrically connected to the first intake valve 122, controlling the first intake valve 122 to automatically adjust the flow rate of silicon source gas in the first intake pipe 121. In one embodiment of this utility model, the first gas-solid separator 31 is a cyclone separator.

[0074] Please see Figures 1 to 5 As shown, in another embodiment of this utility model, a filter membrane 315 is provided on the inner wall of the first gas-solid separator 31. The filter membrane 315 is located at the connection between the first gas-solid separator 31 and the gas separation pipe 311, and intercepts solids to further improve the gas-solid separation effect. The pore size of the filter membrane 315 is, for example, 0.1-1 μm.

[0075] Please see Figures 1 to 5 As shown, the gas alarm 34 is installed at the discharge end of the buffer furnace 22. The gas alarm 34 is not connected to the buffer furnace 22, but is electrically connected to the first inlet valve 122. When the gas alarm 34 detects that the silicon source gas content in the environment near the buffer furnace 22 exceeds the standard, it will sound an alarm and control the first inlet valve 122 to automatically close, preventing explosions from causing harm to the human body and improving production safety.

[0076] Please see Figures 1 to 5As shown, in one embodiment of this utility model, the coating unit 4 includes a coating furnace 41 and a coating inlet pipe 42. The coating inlet pipe 42 extends into the coating furnace 41 to supply coating gas to the coating furnace 41. The coating gas is a mixture of carbon source gas and inert gas, wherein the volume percentage of carbon source gas in the mixture is 60-99 vol%, and the volume percentage of inert gas in the mixture is 1-40 vol%. The carbon source gas is selected from alkane gases with a cracking temperature of 400-1200℃, such as acetylene, ethylene, propylene, propyne, etc., or one or more of these. The inert gas is selected from nitrogen, argon, neon, krypton, xenon, or radon, etc., or one or more of these. The encapsulated air intake pipe 42 is equipped with an encapsulated air intake valve 43, which controls the flow rate of the encapsulated gas to be between 0.1 and 50 L / min. The encapsulated air intake valve 43 is electrically connected to the main controller 33, which controls the encapsulated air intake valve 43 to open and close automatically.

[0077] Please see Figures 1 to 6 As shown, after the material introduced into the coating unit 4 is carbon-coated, it is transported to the receiving unit 5 for processing and collection. The receiving unit 5 includes a second gas-solid separator 51, a transfer chamber 52, a tail gas treatment device 53, and a receiving pipe 55. The transfer chamber 52 is located at the bottom of the second gas-solid separator 51 to cool the solid material separated by the second gas-solid separator 51, and then the cooled material is discharged through the receiving pipe 55. Specifically, the transfer chamber 52 is provided with a hollow jacket 521, and a circulating water cooling coil 54 is installed inside the hollow jacket 521 to cool the material inside the transfer chamber 52. The tail gas separated by the second gas-solid separator 51 is treated by the tail gas treatment device 53. In one embodiment of this utility model, the second gas-solid separator 51 is a cyclone separator.

[0078] Please see Figures 1 to 6 As shown, the method of using a continuous chemical vapor deposition system according to this utility model includes:

[0079] Porous carbon material is introduced into deposition furnace 21 through feed pipe 112. The second inlet valve 125 and the third inlet valve 128 are opened to introduce inert gas into deposition furnace 21, and the flow rate of inert gas is adjusted to 0.1-10 L / min. After the heating component 214 raises the temperature of deposition furnace 21 and buffer furnace 22 to 300-800℃, the first inlet valve 122 is opened to introduce silicon source gas into deposition furnace 21. The gas mixer 126 controls the proportion of silicon source gas in the mixed gas to 60-99 vol%. The third inlet valve 128 adjusts the flow rate of the mixed gas to 0.1-10 L / min.

[0080] The material in the deposition furnace 21 is transported from the deposition furnace 21 to the buffer furnace 22 under the action of the rotation of the furnace body 211 and the guide plate 215. The heating component heats the temperature of the buffer furnace 22 to 300-800℃. Under the high-speed rotation of the buffer furnace 22, the material is further deposited using the unreacted silicon source gas in the buffer furnace 22.

[0081] The main controller 33 controls the gas detection valve 321 to open and controls the gas detector 32 to detect the silicon source gas content in the tail gas every 10 minutes. When the detected silicon source gas content is <0.2mg / L, the main controller controls the coating gas inlet valve 43 to open and introduce coating gas into the coating furnace 41 at a flow rate of 0.1~50L / min. At the same time, the main controller controls the material taking valve 314 to open and the material taking bin 313 automatically takes samples.

[0082] If the silicon source gas content detected by the gas detector 32 is ≥0.2mg / L, it indicates that the silicon source gas has not fully reacted, and the content of unreacted silicon source gas in the tail gas is too high, posing a risk of leakage. In this case, the first inlet valve 122 is closed to cut off the flow of silicon source gas, and the encapsulation inlet valve 43 and the material take-up valve 314 are closed. The staff then inspects the equipment and adjusts the process.

[0083] In summary, this utility model discloses a continuous chemical vapor deposition system. Compared with intermittent deposition equipment, it reduces material transport links between different processes, thereby reducing material loss and the introduction of external impurities, ultimately improving production efficiency and meeting the needs of large-scale production. A buffer furnace is designed at the rear of the deposition furnace to further deposit unreacted silicon source gas, improving raw material utilization and silicon deposition volume, and preventing unreacted silicon source gas from affecting subsequent coating processes. A gas-solid separator, gas detector, and main controller are designed to automatically detect the content of undecomposed silicon source gas. Once the threshold is exceeded, the silicon source supply is cut off, effectively preventing silicon source leakage. A silicon source gas alarm is also installed. When the silicon source gas content in the nearby environment exceeds the standard, an alarm is sounded, and the input of silicon source gas is cut off to prevent explosions and harm to personnel, improving production safety. Simultaneously, real-time sampling of materials can be achieved, allowing for detection of the material deposition state and quality, and timely adjustments to the process based on the structure, improving the electrochemical performance of silicon-carbon anode materials.

[0084] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model. As used herein and throughout the claims below, unless otherwise specified, "a" and "the" include plural references. Similarly, as used herein and throughout the claims below, unless otherwise specified, "in" means "in" and "on".

[0085] The above description of the embodiments shown in this utility model (including the content set forth in the abstract of the specification) is not intended to be an exhaustive enumeration or to limit the utility model to the precise forms disclosed herein. Although specific embodiments and examples of the utility model have been described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the utility model, as will be recognized and understood by those skilled in the art. As indicated, these modifications can be made to the utility model in accordance with the above description of the embodiments described herein, and such modifications will be within the spirit and scope of the utility model.

Claims

1. A continuous chemical vapor deposition system, characterized in that, At least including: A deposition unit includes a deposition furnace and a buffer furnace, wherein the feed end of the buffer furnace is connected to the discharge end of the deposition furnace; The feeding unit is connected to both ends of the deposition furnace; the feeding unit includes a porous carbon feeding device and a gas transmission device, the porous carbon feeding device is connected to the feeding end of the deposition furnace, and the gas transmission device is connected to the discharge end of the deposition furnace; The detection unit, connected to the discharge end of the buffer furnace, performs gas-solid separation on the material in the buffer furnace, automatically detects the gas, and automatically samples the solid; and The coating unit includes a coating furnace and a coating inlet pipe, wherein the coating furnace introduces solid material that has undergone gas-solid separation treatment.

2. The continuous chemical vapor deposition system according to claim 1, characterized in that, The deposition furnace and / or buffer furnace are columnar, and the length-to-diameter ratio of the deposition furnace and / or buffer furnace is 5-15:1; And / or, the deposition furnace and / or buffer furnace includes a furnace body and an outer shell, the outer shell being fitted onto the furnace body; And / or, an insulation layer is provided between the furnace body and the outer shell, and a plurality of heating components are provided within the insulation layer; And / or, the inner wall of the furnace body is provided with a plurality of guide plates, which are evenly distributed along the axial direction of the furnace body; The deposition furnace and / or buffer furnace are mounted on a support, and the support drives the deposition furnace and / or buffer furnace to rotate, with the buffer furnace rotating at a higher speed than the deposition furnace.

3. The continuous chemical vapor deposition system according to claim 1, characterized in that, The detection unit includes a first gas-solid separator, which performs gas-solid separation on the material in the buffer furnace. The gas is discharged from the gas separation pipe, and the solid is discharged from the solid separation pipe.

4. The continuous chemical vapor deposition system according to claim 3, characterized in that, A filter membrane is provided on the inner wall of the first gas-solid separator, and the filter membrane is located at the connection between the first gas-solid separator and the gas separation pipeline.

5. The continuous chemical vapor deposition system according to claim 3, characterized in that, The first gas-solid separator is a cyclone separator.

6. The continuous chemical vapor deposition system according to claim 3, characterized in that, The detection unit also includes a main controller and a gas detector. The gas-solid separator is connected to the gas detector through a gas separation branch pipe to automatically detect the separated gas. The main controller is electrically connected to the gas detector and controls the gas detector to perform automatic detection.

7. The continuous chemical vapor deposition system according to claim 6, characterized in that, The detection unit also includes a material intake bin, and the gas-solid separator is connected to the material intake bin through a solid separation branch pipe; A material sampling valve is installed on the solid separation branch pipeline, and the main controller is electrically connected to the material sampling valve to control the automatic sampling of the material sampling bin.

8. The continuous chemical vapor deposition system according to claim 7, characterized in that, The feeding unit includes a porous carbon feeding device and a gas transmission device. The porous carbon feeding device is connected to the feeding end of the deposition furnace, and the gas transmission device is connected to the discharge end of the deposition furnace. And / or, the porous carbon feeding device includes a feed bin and a feed pipe, the feed pipe extending into the interior of the deposition furnace; And / or, the gas transmission device includes an intake pipe and an intake valve, through which the gas flow rate in the intake pipe is regulated; And / or, the air intake pipe includes a first air intake pipe, a second air intake pipe and a third air intake pipe, the first air intake pipe and the second air intake pipe are connected in parallel to the gas mixer, and the gas mixer is connected to the deposition furnace through the third air intake pipe; And / or, a preheater and a first intake valve are provided on the first intake pipe, wherein the preheater controls the gas temperature in the first intake pipe at 150-250°C. And / or, a second intake valve is provided on the second intake pipe; And / or, a third intake valve is provided on the third intake pipe.

9. The continuous chemical vapor deposition system according to claim 8, characterized in that, The main controller is electrically connected to the first intake valve and controls the first intake valve to close automatically.

10. The continuous chemical vapor deposition system according to claim 8, characterized in that, The detection unit also includes a gas alarm, which is installed at the discharge end of the buffer furnace and is electrically connected to the first inlet valve. When the gas alarm sounds, it controls the first air intake valve to close automatically.

11. The continuous chemical vapor deposition system according to claim 8, characterized in that, The enclosed air intake pipe is equipped with an enclosed air intake valve, and the main controller is electrically connected to the enclosed air intake valve to control the automatic opening and closing of the enclosed air intake valve.

12. The continuous chemical vapor deposition system according to claim 1, characterized in that, The system also includes a receiving unit, which is connected to the discharge end of the coating furnace; The receiving unit includes a second gas-solid separator, which performs gas-solid separation on the material in the coating furnace. The separated gas is transported to the tail gas treatment device, and the separated solid material is transported to the transfer warehouse. And / or, the transfer chamber is provided with a hollow interlayer, and a circulating water cooling coil is installed in the hollow interlayer to cool the materials in the transfer chamber.

13. The continuous chemical vapor deposition system according to claim 12, characterized in that, The second gas-solid separator is a cyclone separator.

14. The continuous chemical vapor deposition system according to claim 11, characterized in that: The main controller controls the gas detector to detect the silicon source gas content every 10 minutes. When the detected silicon source gas content is <0.2mg / L, the controller controls the coating gas inlet valve to open and introduce coating gas into the coating furnace; the controller also controls the material taking valve to open and the material taking hopper to automatically take samples. When the silicon source gas content detected by the gas detector is ≥0.2mg / L, the main controller controls the first air inlet valve to close, and also controls the coating air inlet valve and the material taking valve to close.

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