System and method for preparing gas-phase silicon-carbon negative electrode material

Abstract

The invention discloses a gas-phase silicon-carbon negative electrode material preparation system and method, and belongs to the technical field of silicon-carbon negative electrode materials. According to the preparation system disclosed by the invention, the solid raw material supply device, the fluidized bed reactor, the vapor deposition rotary furnace, the product post-processing device, the heat recycling device and the gas raw material supply system are arranged, so that the problems of small production scale, high production cost and low production efficiency of vapor deposition equipment in preparation of the vapor silicon-carbon negative electrode material are solved; and after engineering amplification of the technology, vapor deposition uniformity is reduced, a filter is frequently blocked, and high-temperature sealing is difficult to realize.

Description

Technical Field

[0001] The present invention belongs to the technical field of silicon-carbon anode materials, and particularly relates to a preparation system and method for a gas-phase silicon-carbon anode material. Background Art

[0002] In recent years, with the continuous growth of the demand for high-efficiency energy conversion and storage tools worldwide, the consumption demand for lithium batteries has increased rapidly. Silicon-based materials are the next-generation lithium battery anode materials, with advantages such as high energy density (4200 mAh / g), long life, and low cost, and are widely used in the fields of consumer electronics, power tools, and power batteries. However, at present, silicon-based anode materials are still in the stage of technological development. Technical problems such as poor material conductivity, electrode cracking caused by volume expansion / shrinkage, and unstable SEI film have greatly restricted the large-scale application of the materials.

[0003] Silicon-carbon anode materials are a new type of silicon-based anode materials formed by compounding nano-silicon and carbon materials. The unique silicon / carbon composite structure can significantly improve the conductivity of the materials and provide a buffer for the volume expansion of the materials, which can greatly improve the electrochemical performance of the materials. At present, silicon-carbon anode materials have gradually replaced graphite anode materials and are continuously penetrating and expanding their applications in consumer batteries and power batteries.

[0004] The main preparation technologies for silicon-carbon anode materials in the industry are mechanical ball milling method and chemical vapor deposition method. The silicon-carbon anode materials prepared by the mechanical ball milling method are also called abrasive silicon-carbon. The process is relatively mature and the equipment investment is small. However, the nano-silicon particles prepared by grinding are relatively large, impurities are easily introduced, and the products have serious agglomeration, resulting in poor cycle performance. Gas-phase silicon-carbon anode materials are prepared by chemical vapor deposition method. The process flow is short and the equipment is few. The structure of silicon-carbon anode materials can be precisely controlled. The products perform excellently in terms of first-cycle efficiency, energy density, cycle performance, etc., and are expected to lead the industrial development of silicon-based anodes in the future.

[0005] The preparation of gas-phase deposition silicon-carbon anode materials mainly uses porous carbon as a carrier, and through two-step CVD reactions of "silicon deposition" and "carbon coating" in sequence, the in-situ composite of silicon / carbon materials and carbon layer coating are realized. However, the solid phase in the gas-phase deposition process belongs to typical C-type particles, with typical characteristics of small particle size, low density, and easy agglomeration. There are obvious "channeling" and large-scale "dead zones" in the fluidization process, which seriously affect the quality of gas-phase deposition and the product performance. At present, gas-phase silicon-carbon anode materials are mostly prepared by a stirred fluidized bed. Through the shear of the paddle blades, the growth of bubbles and the generation of channeling in the bed layer are inhibited, thereby improving the fluidization quality and the uniformity of gas-phase deposition. However, the batch production capacity of the existing technologies and equipment is small. The "multi-unit parallel" method is used for large-scale production, which has disadvantages such as product consistency problems and high costs. In addition, there are still technical problems in the engineering scale-up of the existing technologies and equipment, such as the decrease in gas-phase deposition uniformity, frequent clogging of filters, and difficulty in realizing high-temperature sealing. Summary of the Invention

[0006] The object of the present invention is to provide a preparation system and method for a gas-phase silicon-carbon anode material, which are used to solve the technical problems of high energy consumption, low production efficiency, poor batch stability and difficulty in realizing mass production in the existing preparation process.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] The present invention discloses a preparation system for a gas-phase silicon-carbon anode material, including: a solid raw material supply device, a fluidized bed reactor, a chemical vapor deposition rotary furnace, a product post-treatment device, a heat recovery and utilization device, and a gas raw material supply system; the solid raw material supply device, the fluidized bed reactor, the chemical vapor deposition rotary furnace and the product post-treatment device are sequentially connected through pipelines; the gas raw material supply system is connected to the fluidized bed reactor, the chemical vapor deposition rotary furnace and the product post-treatment device respectively through pipelines; the tops of the solid raw material supply device, the fluidized bed reactor, the chemical vapor deposition rotary furnace and the product post-treatment device are connected to the heat recovery and utilization device through pipelines.

[0009] Further, the solid raw material supply device includes a weighing device and a preheating bin connected in sequence; the weighing device is connected to the top of the preheating bin through a pipeline; the discharge port of the preheating bin is connected to the feed port of the fluidized bed reactor;

[0010] A heating device is arranged in the preheating bin.

[0011] Further, the fluidized bed reactor includes a gas chamber, a reaction section, a cooling section and a separation section connected in sequence from bottom to top; the gas raw material supply system includes nitrogen, a silicon source gas and a carbon source gas.

[0012] Further, the fluidized bed reactor includes a lower head, a nozzle and a gas distributor; the lower head is located at the bottom of the fluidized bed reactor, and the nozzle is located above the lower head; the gas distributor is connected to the nozzle; a cavity is formed between the lower head and the gas distributor to form a gas chamber;

[0013] It also includes a variable-diameter cone, a process gas preheating tube bundle, a cooling tube bundle, a first cylinder and a second cylinder; the upper end of the variable-diameter cone is connected to the lower end of the first cylinder, and the lower end is connected to the upper end of the second cylinder; the process gas preheating tube bundle and the cooling tube bundle are sequentially arranged inside the first cylinder from bottom to top;

[0014] It also includes a central conduit, a flow guiding block and a heating system; the central conduit is located above the gas distributor and has a gap with the nozzle; the heating system is located outside the second cylinder and has a gap between the central conduit and the second cylinder; the flow guiding block is located between the variable-diameter cone and the central conduit;

[0015] It further includes a built-in filter and a top flat cover; the top flat cover is arranged at the upper end of the first cylinder body; the components of the built-in filter pass through the top flat cover and are arranged inside the upper end of the first cylinder body;

[0016] There is a space between the gas distributor and the variable-diameter cone, and this space forms a reaction section; there is a space between the variable-diameter cone and the built-in filter, and this space forms a cooling section; there is a space between the cooling tube bundle and the top flat cover, and this space forms a separation section.

[0017] Further, the gas distributor is of a conical structure and includes an orifice plate and a wire mesh; the orifice plate and the wire mesh are mutually attached, and the wire mesh is arranged on the lower side wall surface of the orifice plate.

[0018] Further, the side wall of the fluidized bed reactor is also provided with a spouting gas inlet, an auxiliary fluidizing gas inlet, a solid feed inlet, a solid discharge outlet, a process gas preheating inlet, a process gas preheating outlet, a fluidized bed cooling medium inlet, a fluidized bed cooling medium outlet, and a tail gas outlet; the spouting gas inlet and the auxiliary fluidizing gas inlet are arranged on the side wall of the gas chamber; the solid feed inlet and the solid discharge outlet are arranged on both sides of the variable-diameter cone; the process gas preheating inlet and the process gas preheating outlet are arranged on the outer side wall of the first cylinder body and are respectively connected to both ends of the internal process gas preheating tube bundle; the fluidized bed cooling medium inlet and the fluidized bed cooling medium outlet are arranged on the outer side wall of the first cylinder body and are respectively connected to both ends of the internal cooling tube bundle; the tail gas outlet is connected to the built-in filter;

[0019] The solid feed inlet is connected to the discharge outlet of the preheating bin; the solid discharge outlet is connected to the feed inlet of the chemical vapor deposition rotary furnace; the spouting gas inlet, the auxiliary fluidizing gas inlet, the process gas preheating inlet, and the process gas preheating outlet are respectively connected to the gas raw material supply system;

[0020] The fluidized bed cooling medium inlet is connected to the cooling medium; the tail gas outlet is connected to the heat recovery and utilization device.

[0021] Further, the product post-treatment device includes a product cooler, a screening device, and a demagnetizer connected in sequence; a first screw conveyor is arranged between the chemical vapor deposition rotary furnace and the product cooler; a second screw conveyor is arranged between the product cooler and the screening device;

[0022] The product cooler includes a conical head, a cylinder body, a flat cover, a pipe orifice filter, a stirrer, a cooling jacket, and a cooler gas distributor; the flat cover is arranged at the upper port of the cylinder body; the conical head is arranged at the lower port of the cylinder body; the components of the stirrer pass through the flat cover and extend into the interior of the cylinder body; the cooling jacket covers the outer surfaces of the conical head and the cylinder body; the cooler gas distributor is arranged inside the lower end of the cylinder body;

[0023] The cylinder of the product cooler is also provided with a cooler feed port, a cooler discharge port, a cooler nitrogen inlet, a cooler tail gas outlet, a cooler cooling medium inlet and a cooler cooling medium outlet;

[0024] The cooler feed port is connected to the discharge port of the chemical vapor deposition rotary furnace through a pipeline; the cooler discharge port is connected to the second screw conveyor; the outside of the cooler nitrogen inlet is connected to a nitrogen pipeline, and the inside is connected to a cooler gas distributor; the cooler cooling medium inlet is connected to the cooling medium; the cooler tail gas outlet is connected to a heat recovery and utilization device through a pipeline; the pipe orifice filter is arranged in the cooler tail gas outlet.

[0025] Further, the heat recovery and utilization device includes a first heat exchanger, a second heat exchanger, a tail gas cooler, a condensate tank, a first filter and a second filter; the tail gas outlet is sequentially connected to the first heat exchanger, the second heat exchanger, the tail gas cooler, the condensate tank, the first filter and the second filter.

[0026] Further, it also includes a first heater, a second heater, a third heater, a fourth heater, a first mixer and a second mixer;

[0027] The nitrogen is divided into three paths in total. The first path of nitrogen is connected to the preheating bin through a pipeline, and the second path of nitrogen is connected to the product cooler through a pipeline; the third path of nitrogen is sequentially connected to the first heat exchanger and the third heater through a pipeline and then respectively connected to the inlets of the first mixer and the second mixer;

[0028] The silicon source gas is connected to the process gas preheating inlet through a pipeline, and after being connected to the first heater through the process gas preheating outlet pipeline, it is connected to the inlet of the first mixer; when the silicon deposition reaction is carried out in the fluidized bed reactor, the silicon source gas and nitrogen are mixed in the first mixer and enter the fluidized bed reactor;

[0029] The carbon source gas is divided into two paths. The first path of carbon source gas is connected to the process gas preheating inlet through a pipeline, and after being connected to the second heater through the process gas preheating outlet pipeline, it is connected to the inlet of the first mixer. When the carbon coating reaction is carried out in the fluidized bed reactor, the carbon source gas and nitrogen are mixed in the first mixer and enter the fluidized bed reactor; the second path of carbon source gas is sequentially connected to the second heat exchanger and the fourth heater through a pipeline and then connected to the inlet of the second mixer; when the deep carbon coating reaction is carried out in the chemical vapor deposition rotary furnace, the carbon source gas and nitrogen are mixed in the second mixer and enter the chemical vapor deposition rotary furnace;

[0030] The outlet of the first mixer is divided into two paths and is respectively connected to the spouting gas inlet and the auxiliary fluidizing gas inlet;

[0031] The tail gas outlet of the preheating bin, the tail gas outlet of the vapor deposition rotary furnace and the tail gas outlet of the product cooler are respectively collected through pipelines and then flow into the tail gas cooler through the first heat exchanger and the second heat exchanger in sequence.

[0032] The present invention also discloses a method for using the above-mentioned gas-phase silicon-carbon negative electrode material preparation system, which comprises the following steps: first, introducing nitrogen from a gas raw material supply system into a solid raw material supply device, and conveying the solid raw material into a fluidized bed reactor; second, introducing a process gas composed of a silicon source gas and nitrogen into the fluidized bed reactor, and carrying out a silicon deposition reaction with the solid raw material to obtain a silicon-carbon intermediate I; then, stopping the silicon source gas, introducing a process gas composed of a carbon source gas and nitrogen into the fluidized bed reactor, and carrying out a carbon coating reaction with the silicon-carbon intermediate I to obtain a silicon-carbon intermediate II; next, introducing nitrogen into the fluidized bed reactor, conveying the silicon-carbon intermediate II to a vapor deposition rotary furnace, and then introducing a process gas composed of a carbon source gas and nitrogen to carry out a deep carbon coating reaction to obtain a silicon-carbon composite material; then, conveying the obtained silicon-carbon composite material to a product post-processing device for treatment to obtain a gas-phase silicon-carbon negative electrode material;

[0033] During the reaction process, the waste heat generated by the solid raw material supply device, fluidized bed reactor, vapor deposition rotary kiln and product post-processing device is recovered through the heat recovery and utilization device.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The present invention discloses a gas phase silicon carbon anode material preparation system. By setting a solid raw material supply device, a fluidized bed reactor, a vapor deposition rotary kiln, a product post-processing device, a heat recovery device and a gas raw material supply system, it is suitable for gas phase "silicon deposition" and gas phase "carbon coating" operations on 5-15um porous carbon as a carrier. It can achieve stable internal circulation jet fluidization of the particle phase and waste heat recovery and utilization in the process of preparing silicon carbon anode materials by vapor deposition method. During the operation, it is unnecessary to frequently operate high temperature equipment such as fluidized bed reactor and CVD rotary kiln. Large-scale temperature increase and decrease can reduce comprehensive energy consumption, improve production efficiency, and be beneficial to reducing production costs and compressing production cycles in the large-scale preparation of gas-phase silicon-carbon negative electrode materials. The process system has the advantages of tight process, high production efficiency, low comprehensive energy consumption, and low operating costs, which can meet the large-scale and controllable preparation of high-quality gas-phase silicon-carbon negative electrode materials, and solve the technical problems of small production scale and high production cost of vapor deposition equipment in the preparation of gas-phase silicon-carbon negative electrode materials, decreased uniformity of vapor deposition after technical engineering amplification, frequent filter clogging, and difficulty in achieving high-temperature sealing.

[0036] Furthermore, the fluidized bed reactor is arranged from bottom to top in sequence with a gas chamber, a reaction section, a cooling section and a separation section connected in turn. By relying only on pneumatic action and fixed internal components, a stable internal circulation spouting fluidization of the particle phase is achieved, creating good gas-solid contact reaction conditions for the effective progress of gas-phase deposition. It has the advantages of small technical magnification effect, good batch stability of product quality, convenience in equipment enlargement, etc., meeting the requirements of the macroscale preparation technology of gas-phase silicon-carbon anode materials. The arranged cooling tube bundle can recover the waste heat of the reaction tail gas while reducing the tail gas temperature, avoiding the pyrolysis deposition of unreacted process gas on the surface of the built-in filter, and effectively solving the production problem of frequent blockage of the built-in filter.

[0037] Furthermore, the product cooler adopts a synchronous cooling operation of direct contact with nitrogen and indirect heat exchange with a cooling medium, which can effectively prevent the product powder from sticking into lumps and can significantly improve the cooling efficiency of the product powder, saving production time. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a schematic diagram of the overall structure of the gas-phase silicon-carbon anode material preparation system of the present invention;

[0039] Figure 2 is a schematic diagram of the structure of the fluidized bed reactor of the present invention;

[0040] Figure 3 is a schematic diagram of the structure of the gas distributor of the present invention;

[0041] Figure 4 is a schematic diagram of the structure of the product cooler of the present invention;

[0042] Wherein: 1 - weighing device; 2 - preheating bin; 3 - fluidized bed reactor; 301 - lower head; 302 - nozzle; 303 - heating system; 304 - central duct; 305 - flow guiding block; 306 - reducing cone; 307 - process gas preheating tube bundle; 308 - cooling tube bundle; 309 - built-in filter; 310 - top flat cover; 311 - first cylinder; 312 - second cylinder; 313 - gas distributor; 3131 - orifice plate; 3132 - wire mesh; N1 - spouting gas inlet; N2 - auxiliary fluidizing gas inlet; N3 - solid feed inlet; N4 - solid discharge outlet; N5 - process gas preheating inlet; N6 - process gas preheating outlet; N7 - fluidized bed cooling medium inlet; N8 - fluidized bed cooling medium outlet; N9 - tail gas outlet; T1 - bed temperature measuring port I; T2 - side bed temperature measuring port II, T3 - top temperature measuring port, P1 - bed pressure measuring port, P2 - top pressure measuring port; 4 - first heat exchanger; 5 - first heater; 6 - second heater; 7 - third heater; 8 - first mixer; 9 - tail gas cooler; 10 - condensate tank; 11 - second heat exchanger; 12 - fourth heater; 13 - second mixer; 14 - chemical vapor deposition rotary furnace; 15 - first screw conveyor; 16 - product cooler; 1601 - conical head; 1602 - cylinder; 1603 - flat cover; 1604 - pipe orifice filter; 1605 - agitator; 1606 - cooling jacket; 1607 - cooler gas distributor; N10 - cooler feed inlet; N11 - cooler discharge outlet; N12 - cooler nitrogen inlet; N13 - cooler tail gas outlet; N14 - cooler cooling medium inlet; N15 - cooler cooling medium outlet; T - cooler powder temperature measuring port; P - cooler gas phase pressure measuring port; 17 - second screw conveyor; 18 - screening device; 19 - demagnetizer; 20 - first filter; 21 - second filter. Detailed implementation manners

[0043] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0044] It should be noted that the terms "first", "second", etc. in the description, claims and the above-mentioned drawings of the present invention are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0045] The present invention will be further described in detail below with reference to the accompanying drawings:

[0046] The present invention discloses a preparation system for a gas-phase silicon-carbon anode material, comprising: a solid raw material supply device, a fluidized bed reactor 3, a chemical vapor deposition rotary furnace 14, a product post-treatment device, a heat recovery and utilization device, and a gas raw material supply system; the solid raw material supply device, the fluidized bed reactor 3, the chemical vapor deposition rotary furnace 14 and the product post-treatment device are sequentially connected through pipelines; the gas raw material supply system is connected to the fluidized bed reactor 3 and the chemical vapor deposition rotary furnace 14 respectively through pipelines; the tops of the solid raw material supply device, the fluidized bed reactor 3, the chemical vapor deposition rotary furnace 14 and the product post-treatment device are connected to the heat recovery and utilization device through pipelines; through methods such as modern heating technology, internal circulation spouted bed technology, heat recovery technology and process system coupling, a set of complete technologies and equipment for large-scale preparation of gas-phase silicon-carbon anode materials is provided, which has the characteristics of small engineering scale-up effect, easy equipment enlargement, low comprehensive energy consumption, good product quality, high production efficiency, etc., and is suitable for large-scale preparation of high-quality and low-cost gas-phase silicon-carbon anode materials.

[0047] Specifically, as Figures 1 to 4 shown, the solid raw material supply device includes a weighing device 1 and a preheating bin 2 connected in sequence; the gas raw material supply system includes nitrogen, a silicon source gas and a carbon source gas; the weighing device 1 is connected to the top of the preheating bin 2 through a pipeline; the discharge port of the preheating bin 2 is connected to the feed port of the fluidized bed reactor 3; the fluidized bed reactor 3 includes, from bottom to top, a gas chamber, a reaction section, a cooling section and a separation section in sequence; the product post-treatment device includes a product cooler 16, a screening device 18 and a demagnetizer 19 connected in sequence; the heat recovery and utilization device includes a tail gas cooler 9, a condensate tank 10, a first heat exchanger 4, a second heat exchanger 11, a first filter 20 and a second filter 21.

[0048] Preferably, the weighing device 1 can be a metering silo with a weighing sensor or a screw metering feeder, preferably a screw metering feeder; a heating device is arranged in the preheating bin 2, which can be one of a resistance heater, a microwave heater and an inductive heater, preferably a microwave heater.

[0049] Preferably, the fluidized bed reactor 3 includes a lower head 301, a nozzle 302, a gas distributor 313, a central conduit 304, a flow guide block 305, a heating system 303, a reducing cone 306, a process gas preheating tube bundle 307, a cooling tube bundle 308, a first cylinder 311, a second cylinder 312, an internal filter 309, and a top flat cover 310; the lower head 301 is located at the bottom of the fluidized bed reactor 3, and the nozzle 302 is located at the upper end of the lower head 301; the gas distributor 313 is connected to the nozzle 302; the central conduit 304 is located at the upper end of the gas distributor 313 and there is a gap between the central conduit 304 and the nozzle 302; the heating system 303 is located outside the second cylinder 312; there is a gap between the central conduit 304 and the second cylinder 312; the upper end of the reducing cone 306 is connected to the lower end of the first cylinder 311, and the lower end is connected to the upper end of the second cylinder 312; the process gas preheating tube bundle 307 and the cooling tube bundle 308 are sequentially arranged inside the first cylinder 311 from bottom to top; the top flat cover 310 covers the upper end of the first cylinder 311; the internal filter 309 assembly passes through the top flat cover 310 and is arranged inside the upper end of the first cylinder 311; wherein, the gas chamber is the space between the lower head 301 and the gas distributor 313, the reaction section is the space between the gas distributor 313 and the reducing cone 306, the cooling section is the space between the reducing cone 306 and the internal filter 309, and the separation section is the space between the cooling tube bundle 308 and the top flat cover 310.

[0050] Preferably, the side wall of the fluidized bed reactor 3 is further provided with a spouting gas inlet N1, an auxiliary fluidizing gas inlet N2, a solid feed inlet N3, a solid discharge outlet N4, a process gas preheating inlet N5, a process gas preheating outlet N6, a fluidized bed cooling medium inlet N7, a fluidized bed cooling medium outlet N8, and a tail gas outlet N9; the spouting gas inlet N1 and the auxiliary fluidizing gas inlet N2 are arranged on the side wall of the gas chamber; the solid feed inlet N3 and the solid discharge outlet N4 are arranged on both sides of the variable diameter cone 306; the process gas preheating inlet N5 and the process gas preheating outlet N6 are arranged on the outer side wall of the first cylinder 311 and are respectively connected to both ends of the internal process gas preheating tube bundle 307; the fluidized bed cooling medium inlet N7 and the fluidized bed cooling medium outlet N8 are arranged on the outer side wall of the first cylinder 311 and are respectively connected to both ends of the internal cooling tube bundle 308; the tail gas outlet N9 is connected to the filter 309; the solid feed inlet N3 is connected to the discharge outlet of the preheating bin 2; the solid discharge outlet N4 is connected to the feed inlet of the chemical vapor deposition rotary furnace 14; the spouting gas inlet N1, the auxiliary fluidizing gas inlet N2, the process gas preheating inlet N5, and the process gas preheating outlet N6 are respectively connected to the gas raw material supply system; the fluidized bed cooling medium inlet N7 is connected to the cooling medium; the tail gas outlet N9 is connected to the heat recovery and utilization device.

[0051] The above-mentioned fluidized bed reactor 3 is composed of four parts, namely a gas chamber, a reaction section, a cooling section, and a separation section from bottom to top, forming an internal circulation spouting fluidization of particles in the reactor to complete the pyrolysis deposition reaction of the process gas. The specific structural features are as follows:

[0052] The gas chamber is the space between the lower head 301 and the gas distributor 313, with an external spouting gas inlet N1 and an auxiliary fluidizing gas inlet N2 to achieve the sectional feeding and distribution of gas; the reaction section is the space between the gas distributor 313 and the variable-diameter section 306, with an external heating system 303 in the reaction section, and a gas distributor 313, nozzles 302, a central conduit 304, and a flow guide block 305 inside; the gas distributor 313 is of a conical structure, and the half-cone angle α is less than the complementary angle of the angle of repose of the particle phase. Specifically, it consists of an orifice plate 3131 and a wire mesh 3132 to achieve the uniform distribution of the auxiliary fluidizing gas. The orifice plate 3131 is preferably a stainless steel perforated plate with a pore diameter of 3 - 6 mm, the center distance of the pores is 1.25 times the pore diameter, and the pore distribution can be any one of equilateral triangle, corner triangle, square, or corner square, preferably an equilateral triangle; the wire mesh 3132 is a stainless steel wire mesh with 400 - 800 meshes, welded below the orifice plate 3131; the nozzle 302 is connected to the small end of the cone of the gas distributor 313, and the throat diameter is d1. To achieve the spouting fluidization of the particle phase, the value of d1 needs to ensure that the injection gas velocity is greater than the minimum spouting velocity of the particles. The central conduit 304 is arranged at the center of the second cylinder 312, with a diameter of d2, and the distance from the lower end to the nozzle 302 is H1, and it is required that d2 ≧ d1 + (0.2 - 0.5) * H1; the flow guide block 305 is of an inverted isosceles triangle structure, the center line is aligned with the axis of the central conduit 304, the bottom side length is L, L ≧ (1.2 - 1.8) * d2, the apex angle is β, and it is required that β = 90 - 120°, and the distance from the lower vertex to the upper end of the central conduit 304 is H2, and it is required that H2 ≧ (1.5 - 2) * d2; in addition, bed temperature measurement ports T1 and T2 are arranged from bottom to top in the reaction section, and there can be 2 - 3 measuring points for T1 and T2 along the axis. A bed pressure measurement port P1 is arranged in the middle of the reaction section, and the pressure guiding pipe of the pressure measurement port has an anti-blowing function; the cooling section is the space between the variable-diameter cone 306 and the built-in filter 309, with a process gas preheating tube bundle 307 and a cooling tube bundle 308 inside; to effectively cool the tail gas of the gas-phase deposition reaction, the target temperature is 20 - 50 °C below the pyrolysis temperature of the process gas, to avoid the pyrolysis deposition of the unreacted process gas on the surface of the built-in filter and prevent the blockage of the pores of the filter element; in addition, a solid feed port N3 and a solid discharge port N4 are arranged in the middle of the variable-diameter cone of the cooling section, connecting the pipeline for nitrogen-pressurized materials.

[0053] The separation section is the space between the cooling tube bundle 308 and the top flat cover 310, with a built-in filter 309 to achieve gas-solid separation; the filter element of the built-in filter 309 is made of a high-temperature-resistant material and has a pulse anti-blowing function. The filter element can be one of a metal sintered filter element or a ceramic filter element, preferably a metal sintered filter element of 310S material; in addition, a top temperature measurement port T3 and a top pressure measurement port P2 are arranged in the upper part of the separation section to detect the temperature and pressure of the tail gas in the separation section.

[0054] As Figure 3As shown, more specifically, the gas distributor 313 is a conical structure, including an orifice plate 3131 and a wire mesh 3132; the orifice plate 3131 and the wire mesh 3132 are attached to each other, and the wire mesh 3132 is disposed on the outer wall surface of the orifice plate 3131.

[0055] As Figure 4 As shown, the product cooler 16 includes a conical head 1601, a cylinder 1602, a flat cover 1603, a pipe orifice filter 1604, an agitator 1605, a cooling jacket 1606, and a cooler gas distributor 1607; the flat cover 1603 is disposed at the upper port of the cylinder 1602; the conical head 1601 is disposed at the lower port of the cylinder 1602; the agitator 1605 assembly passes through the flat cover 1603 and extends into the interior of the cylinder 1602; the cooling jacket 1606 is coated on the outer surfaces of the conical head 1601 and the cylinder 1602; the cooler gas distributor 1607 is disposed inside the lower end of the cylinder 1602;

[0056] The cylinder 1602 of the product cooler 16 is further provided with a cooler feed port N10, a cooler discharge port N11, a cooler nitrogen inlet N12, a cooler tail gas outlet N13, a cooler cooling medium inlet N14, and a cooler cooling medium outlet N15; the cooler feed port N10 is connected to the discharge port of the chemical vapor deposition rotary furnace 14 through a pipeline; the cooler discharge port N11 is connected to the second screw conveyor 17; the outside of the cooler nitrogen inlet N12 is connected to a nitrogen pipeline, and the inside is connected to the cooler gas distributor 1607; the cooler cooling medium inlet N14 is connected to a cooling medium; the cooler tail gas outlet N13 is sequentially connected to a heat recovery and utilization device through a pipeline; the pipe orifice filter 1604 is disposed in the cooler tail gas outlet N13.

[0057] Preferably, the product cooler 16 is a vertical structure with a conical bottom and a flat cover, equipped with an agitator 1605 inside, a cooling jacket 1606 outside, and a cooler gas distributor 1607 at the bottom; the agitator 1605 can be any one or a combination of a frame agitator, an anchor agitator, and a helical ribbon agitator, preferably a helical ribbon agitator; the cooling jacket 1606 can be an integral jacket, a half-pipe jacket, or a honeycomb jacket, preferably an integral jacket; the cooler gas distributor 1607 can be an annular perforated pipe or an annular porous pipe, preferably a ceramic or powder metallurgy annular porous pipe; in addition, the product cooler 16 is provided with a cooler feed port N10 and a cooler discharge port N11 to realize powder feeding and discharging; a pipe orifice filter 1604 is disposed inside the cooler tail gas outlet N13 to realize the filtration and discharge of cooling nitrogen; the cooler gas-phase pressure measuring port P and the cooler powder temperature measuring port T respectively realize the detection of the material layer temperature and the gas-phase pressure of the product cooler 16.

[0058] When the above system is in use, it includes the following steps:

[0059] Step 1: Use nitrogen to displace the closed system after the preheating chamber 2 in the system. Stop the displacement when the oxygen content in the displacement tail gas is below 10 - 20 PPM. During this period, preheat the fluidized bed reactor 3 and the chemical vapor deposition rotary furnace 14 simultaneously, with the preheating temperature being 400 - 750 °C.

[0060] Step 2: Add porous carbon to the weighing device 1. After weighing the specified weight of porous carbon, add it to the preheating chamber 2 in batches.

[0061] Step 3: Introduce nitrogen from the bottom of the preheating chamber 2 to displace the atmosphere in the chamber. After 10 - 20 minutes, turn on the internal heating device of the preheating chamber 2 to directly heat the porous carbon, with the end temperature being 400 - 750 °C. After the temperature reaches the standard, detect the oxygen content of the tail gas at the top of the preheating chamber 2. When the oxygen content is below 10 - 20 PPM, shut down the nitrogen for displacement at the bottom of the chamber, open the nitrogen for transportation at the top of the chamber, and press the preheated porous carbon into the fluidized bed reactor 3.

[0062] Step 4: Turn on the silicon source gas. The silicon source gas is preheated to 300 - 350 °C successively through the process gas preheating tube bundle 307 and the first heater 5 in the fluidized bed reactor 3. Nitrogen is preheated to 300 - 350 °C successively through the first heat exchanger 4 and the third heater 7. After the preheated silicon source gas and nitrogen are fully mixed in the first mixer 8, they are fed into the fluidized bed reactor 3 through the spouting gas inlet N1 and the auxiliary fluidizing gas inlet N2 in two paths to achieve internal circulation spouting fluidization of the particles. During the process, the fluidized bed reactor 3 maintains a slightly positive pressure state of 1 - 50 KPaG and a reaction temperature of 400 - 650 °C to achieve gas-phase pyrolysis deposition of the silicon source. After 5 - 20 hours, the silicon deposition reaction ends, and silicon-carbon intermediate Ⅰ is obtained.

[0063] Step 5: Turn off the silicon source gas, turn on the carbon source gas, which is preheated to 250 - 300 °C successively through the process gas preheating tube bundle 307 and the second heater 6 in the fluidized bed reactor 3. Nitrogen is preheated to 250 - 300 °C successively through the first heat exchanger 4 and the third heater 7. After the preheated carbon source gas and nitrogen are fully mixed in the first mixer 8, they are fed into the fluidized bed reactor 3 through the spouting gas inlet N1 and the auxiliary fluidizing gas inlet N2 in two paths to achieve internal circulation spouting fluidization of the particles. During the process, the fluidized bed reactor 3 maintains a slightly positive pressure state of 1 - 50 KPaG and a reaction temperature of 400 - 700 °C to achieve gas-phase pyrolysis deposition of the carbon source. After the 1 - 10-hour carbon coating reaction ends, silicon-carbon intermediate Ⅱ is obtained.

[0064] Step 6: Use nitrogen to press the silicon-carbon intermediate II from the fluidized bed reactor 3 into the chemical vapor deposition rotary furnace 14. The carbon source gas is preheated to 250-300°C successively through the second heat exchanger 11 and the fourth heater 12; nitrogen is preheated to 250-300°C successively through the first heat exchanger 4 and the third heater 7. The preheated carbon source gas and nitrogen are mixed evenly in the second mixer 13 and then introduced into the chemical vapor deposition rotary furnace 14. During the process, the chemical vapor deposition rotary furnace 14 maintains a slightly positive pressure of 1-50 KPaG and a temperature of 450-700°C to achieve the gas-phase pyrolysis deposition of the carbon source. After 5-20 hours of deep carbon coating, the silicon-carbon composite material is obtained;

[0065] Step 7: The high-temperature silicon-carbon composite material is transported by the first screw conveyor 15 to the product cooler 16 for cooling, and the target temperature is 50-60°C;

[0066] Step 8: The cooled silicon-carbon composite material is transported by the second screw conveyor 17 to the screening device 18 to remove large-particle silicon-carbon anode materials. During the process, the silicon-carbon composite materials with unqualified particle sizes are sent for recycling;

[0067] Step 9: After the silicon-carbon composite material with qualified particle sizes is removed of ferromagnetic substances by the demagnetizer 19, the product silicon-carbon anode product is obtained, and the final product silicon-carbon anode material is sent for packaging.

[0068] During the above process, the high-temperature tail gas generated by the preheating bin 2, the fluidized bed reactor 3, the chemical vapor deposition rotary furnace 14, and the product cooler 16 is collected through pipelines, and the heat is recovered successively by the first heat exchanger 4 and the second heat exchanger 11 and then enters the tail gas cooler 9 for deep cooling, with the target temperature of 50-60°C; subsequently, the cold tail gas is deeply purified through the first filter 20 and the second filter 21 and then enters the flare for incineration treatment. During the process, the condensate generated in the tail gas cooler 9 enters the condensate tank 10 for regular recovery.

[0069] Specifically, the gas-phase deposition reaction process in the fluidized bed reactor 3 is as follows:

[0070] The process mixed gas enters the reactor under slightly positive pressure in two paths. One path serves as the spouting gas and enters the reactor through the spouting gas inlet N1. Utilizing the "jet effect" of the nozzle 302, it entrains the bottom porous carbon particles and ascends along the central conduit 304 in a transport bed state. After the gas-solid two-phase separates from the central conduit 304, a "fountain area" is formed in the upper space of the second cylinder 312. Under the action of the deflector block 305 and gravity, the particles fall back to the annular gap area between the second cylinder 312 and the central conduit 304 and move to the bottom of the bed in a downward flow bed state, and are re-entrained by the spouting gas jet, forming an internal particle circulation motion state in the reactor. The other path of the process mixed gas serves as the auxiliary fluidizing gas and enters the bottom of the reactor through the auxiliary fluidizing gas inlet N2. Under the action of the gas distributor 313, it evenly enters the annular gap area between the second cylinder 312 and the central conduit 304, fully contacts the particles in the downward flow bed, ensuring that the bed layer in the annular gap area is loosened and in a continuous downward movement state. Under the special bed layer structure, the gas-solid two-phase presents a stable internal circulation spouting fluidization state in the fluidized bed reactor 3. Further, under the temperature conditions provided by the heating system 303, the process gas realizes gas-phase pyrolysis deposition.

[0071] Preferably, the first screw conveyor 15 has a high-temperature resistant structure. In addition to the traditional structural features, an external cooling jacket 1606 is provided, and the stirring shaft is of a hollow structure with a cooling medium passing through it.

[0072] Preferably, the product cooler 16 adopts a synchronous cooling method combining direct cooling and indirect cooling. During the operation, normal temperature nitrogen gas is introduced through the cooler nitrogen inlet N12 of the product cooler 16. After being distributed by the cooler gas distributor 1607, it directly contacts and cools the product powder. On the other hand, the cooling medium is introduced into the cooling jacket 1606, and the indirect cooling of the product powder is achieved through heat transfer by the metal wall surface. During the process, the stirrer 1605 is continuously turned on to increase the heat transfer efficiency of the bed layer. The stirring speed is 1 - 80 rpm. After continuous cooling for 2 - 4 h, the product powder can be cooled down to 50 - 60 °C.

[0073] The cooling medium in the process flow can be any one of chilled water, circulating water, and heat transfer oil, preferably chilled water.

[0074] Example 1

[0075] After nitrogen replacement and device preheating of the closed system after the preheating bin 2, particles with a particle size of 10 - 15 μm and a bulk density of 0.5 g / cm 3The porous carbon is added to the weighing device 1, and 10 kg of porous carbon is metered and added to the preheating bin 2. After nitrogen replacement for 10 minutes, the oxygen content meets the standard; subsequently, the heating device of the preheating bin 2 is started, and the porous carbon is heated to 560 °C, and then the high-temperature porous carbon is sent to the fluidized bed reactor by nitrogen; next, the silicon source gas is turned on, and both the silicon source gas and nitrogen are preheated to 300 °C and then mixed, and are fed into the fluidized bed reactor 3 in two paths to form an internal circulation spouted fluidization in the reaction space; during the process, the fluidized bed reactor 3 maintains the reaction chamber temperature at 560 °C through the heating system 303 to realize the pyrolysis deposition reaction of the silicon source gas. After the reaction tail gas is cooled to 480 °C by the cooling tube bundle 308 in the fluidized bed reactor 3, it enters the built-in filter 309 for purification and discharge. After 12 hours, the silicon deposition ends, and silicon-carbon intermediate Ⅰ is obtained; next, the silicon source gas is turned off, the carbon source gas is turned on, and both the carbon source gas and nitrogen are preheated to 250 °C and then mixed, and are fed into the fluidized bed reactor 3 in two paths to form an internal circulation spouted fluidization in the reaction space; during the process, the fluidized bed reactor 3 maintains the reaction chamber temperature at 650 °C through the heating system 303 to realize the pyrolysis deposition reaction of the carbon source gas. After the reaction tail gas is cooled to 400 °C by the cooling tube bundle 308 in the fluidized bed reactor 3, it enters the built-in filter 309 for purification and discharge. After 4 hours, the carbon coating ends, and silicon-carbon intermediate Ⅱ is obtained; next, the silicon-carbon intermediate Ⅱ is sent to the chemical vapor deposition rotary furnace 14 by nitrogen. The carbon source gas and nitrogen are preheated to 280 °C and then mixed and fed into the chemical vapor deposition rotary furnace 14. During the process, the chemical vapor deposition rotary furnace 14 maintains the reaction chamber temperature at 700 °C through the heating device to realize the pyrolysis deposition reaction of the carbon source gas. After 10 hours, the deep carbon coating ends, and the silicon-carbon composite material is obtained; next, the first screw conveyor 15 transports the high-temperature silicon-carbon material at 700 °C to the product cooler 16, and the silicon-carbon composite material is synchronously cooled by normal-temperature nitrogen and chilled water. After 3 hours, the material temperature drops to 60 °C; next, the cooled silicon-carbon composite material is transported to the screening device 18 and the demagnetizer 19 by the second screw conveyor 17, and after removing large particles and ferromagnetic substances, a silicon-carbon negative electrode product with a particle size of 12-18 um and a bulk density of 0.95 g / cm 3 is obtained and sent out for packaging; the high-temperature tail gas generated during the system operation is sent to the flare system after heat recovery and dust removal and purification, the condensate is recovered regularly, and the silicon-carbon materials with unqualified particle sizes and the dust removal powder are sent for recycling treatment.

[0076] Example 2

[0077] After nitrogen replacement and device preheating of the closed system behind the preheating bin 2, porous carbon with a particle size of 8-12 um and a bulk density of 0.4 g / cm 3The porous carbon is added to the weighing device 1, and 25 kg of porous carbon is metered and added to the preheating bin 2. After nitrogen replacement for 15 minutes, the oxygen content meets the standard; subsequently, the heating device of the preheating bin 2 is started, and the porous carbon is heated to 600 °C, and then the high-temperature porous carbon is pressed into the fluidized bed reactor 3 by nitrogen; next, the silicon source gas is turned on, and both the silicon source gas and nitrogen are preheated to 320 °C and then mixed, and are fed into the fluidized bed reactor 3 in two paths to form an internal circulation spouted fluidization in the reaction space; during the process, the fluidized bed reactor 3 maintains the reaction chamber temperature at 600 °C through the heating system 303 to realize the pyrolysis deposition reaction of the silicon source gas. After the reaction tail gas is cooled to 450 °C by the cooling tube bundle 308 in the fluidized bed reactor 3, it enters the built-in filter 309 for purification and discharge. After 15 hours, the silicon deposition ends, and silicon-carbon intermediate Ⅰ is obtained; next, the silicon source gas is turned off, the carbon source gas is turned on, and both the carbon source gas and nitrogen are preheated to 280 °C and then mixed, and are fed into the fluidized bed reactor 3 in two paths to form an internal circulation spouted fluidization in the reaction space; during the process, the fluidized bed reactor 3 maintains the reaction chamber temperature at 700 °C through the heating system 303 to realize the pyrolysis deposition reaction of the carbon source gas. After the reaction tail gas is cooled to 430 °C by the cooling tube bundle 308 in the fluidized bed reactor 3, it enters the built-in filter 309 for purification and discharge. After 6 hours, the carbon coating ends, and silicon-carbon intermediate Ⅱ is obtained; next, the silicon-carbon intermediate Ⅱ is pressed into the chemical vapor deposition rotary furnace 14 by nitrogen, and the carbon source gas and nitrogen are preheated to 300 °C and then mixed and fed into the chemical vapor deposition rotary furnace 14. During the process, the chemical vapor deposition rotary furnace 14 maintains the reaction chamber temperature at 720 °C through the heating device to realize the pyrolysis deposition reaction of the carbon source gas. After 15 hours, the deep carbon coating ends, and the silicon-carbon composite material is obtained; next, the first screw conveyor 15 conveys the high-temperature silicon-carbon material at 720 °C into the product cooler 16, and the silicon-carbon composite material is synchronously cooled by normal-temperature nitrogen and chilled water. After 2 hours, the material temperature drops to 80 °C; next, the cooled silicon-carbon composite material is conveyed to the screening device 18 and the demagnetizer 19 through the second screw conveyor 17, and after removing large particles and ferromagnetic substances, the silicon-carbon negative electrode product with a particle size of 10-15 um and a bulk density of 1.1 g / cm 3 is obtained and sent out for packaging. The high-temperature tail gas generated during the system operation is sent to the flare system after heat recovery and dust removal and purification. The condensate is regularly recovered, and the silicon-carbon materials with unqualified particle sizes and the dust removal powder are sent for recycling and treatment.

[0078] The above content is only to illustrate the technical idea of the present invention, and the protection scope of the present invention cannot be limited thereby. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.

Claims

1. A preparation system for a gas-phase silicon-carbon anode material, characterized in that, Including: A solid raw material supply device, a fluidized bed reactor (3), a chemical vapor deposition rotary furnace (14), a product post-treatment device, a heat recovery and utilization device, and a gas raw material supply system; the solid raw material supply device, the fluidized bed reactor (3), the chemical vapor deposition rotary furnace (14), and the product post-treatment device are sequentially connected by pipelines; the gas raw material supply system is connected to the fluidized bed reactor (3), the chemical vapor deposition rotary furnace (14), and the product post-treatment device respectively by pipelines; the tops of the solid raw material supply device, the fluidized bed reactor (3), the chemical vapor deposition rotary furnace (14), and the product post-treatment device are connected to the heat recovery and utilization device by pipelines.

2. The preparation system of a gas-phase silicon-carbon anode material according to claim 1, wherein The solid raw material supply device includes a weighing device (1) and a preheating bin (2) connected in sequence; the weighing device (1) is connected to the top of the preheating bin (2) by a pipeline; the discharge port of the preheating bin (2) is connected to the feed port of the fluidized bed reactor (3); A heating device is arranged in the preheating bin (2).

3. The preparation system for a gas-phase silicon-carbon anode material according to claim 1, wherein, The fluidized bed reactor (3) includes a gas chamber, a reaction section, a cooling section, and a separation section connected in sequence from bottom to top; the gas raw material supply system includes nitrogen, a silicon source gas, and a carbon source gas.

4. The preparation system of a gas-phase silicon-carbon anode material according to claim 3, characterized in that, The fluidized bed reactor (3) includes a lower head (301), a nozzle (302), and a gas distributor (313); the lower head (301) is located at the bottom of the fluidized bed reactor (3), the nozzle (302) is located above the lower head (301); the gas distributor (313) is connected to the nozzle (302); a cavity is formed between the lower head (301) and the gas distributor (313) to form a gas chamber; It also includes a reduced-diameter cone (306), a process gas preheating tube bundle (307), a cooling tube bundle (308), a first cylinder (311), and a second cylinder (312); the upper end of the reduced-diameter cone (306) is connected to the lower end of the first cylinder (311), and the lower end is connected to the upper end of the second cylinder (312); the process gas preheating tube bundle (307) and the cooling tube bundle (308) are sequentially arranged inside the first cylinder (311) from bottom to top; It also includes a central conduit (304), a flow guide block (305), and a heating system (303); the central conduit (304) is located above the gas distributor (313) and has a gap with the nozzle (302); the heating system (303) is located outside the second cylinder (312) and has a gap between the central conduit (304) and the second cylinder (312); the flow guide block (305) is located between the reduced-diameter cone (306) and the central conduit (304); It also includes an internal filter (309) and a top flat cover (310); the top flat cover (310) is arranged at the upper end of the first cylinder (311); the components of the internal filter (309) pass through the top flat cover (310) and are arranged inside the upper end of the first cylinder (311); There is a space between the gas distributor (313) and the variable-diameter cone (306), and this space forms the reaction section; there is a space between the variable-diameter cone (306) and the built-in filter (309), and this space forms the cooling section; there is a space between the cooling tube bundle (308) and the top flat cover (310), and this space forms the separation section.

5. A preparation system for a gas-phase silicon-carbon anode material according to claim 4, characterized in that, The gas distributor (313) is of a conical structure and includes an orifice plate (3131) and a wire mesh (3132); the orifice plate (3131) and the wire mesh (3132) are mutually adhered, and the wire mesh (3132) is arranged on the lower sidewall surface of the orifice plate (3131).

6. The preparation system of a gas-phase silicon-carbon anode material according to claim 4, characterized in that, The sidewall of the fluidized bed reactor (3) is further provided with a spouting gas inlet (N1), an auxiliary fluidizing gas inlet (N2), a solid feed inlet (N3), a solid discharge outlet (N4), a process gas preheating inlet (N5), a process gas preheating outlet (N6), a fluidized bed cooling medium inlet (N7), a fluidized bed cooling medium outlet (N8), and a tail gas outlet (N9); the spouting gas inlet (N1) and the auxiliary fluidizing gas inlet (N2) are arranged on the sidewall of the gas chamber; the solid feed inlet (N3) and the solid discharge outlet (N4) are arranged on both sides of the variable-diameter cone (306); the process gas preheating inlet (N5) and the process gas preheating outlet (N6) are arranged on the outer sidewall of the first cylinder (311) and are respectively connected to both ends of the internal process gas preheating tube bundle (307); the fluidized bed cooling medium inlet (N7) and the fluidized bed cooling medium outlet (N8) are arranged on the outer sidewall of the first cylinder (311) and are respectively connected to both ends of the internal cooling tube bundle (308); the tail gas outlet (N9) is connected to the built-in filter (309); The solid feed inlet (N3) is connected to the discharge outlet of the preheating bin (2); the solid discharge outlet (N4) is connected to the feed inlet of the chemical vapor deposition rotary furnace (14); the spouting gas inlet (N1), the auxiliary fluidizing gas inlet (N2), the process gas preheating inlet (N5), and the process gas preheating outlet (N6) are respectively connected to the gas raw material supply system; The fluidized bed cooling medium inlet (N7) is connected to the cooling medium; the tail gas outlet (N9) is connected to the heat recovery and utilization device.

7. The preparation system for a gas-phase silicon-carbon anode material according to claim 6, wherein, The product post-treatment device includes a product cooler (16), a screening device (18), and a demagnetizer (19) connected in sequence; a first screw conveyor (15) is arranged between the chemical vapor deposition rotary furnace (14) and the product cooler (16); a second screw conveyor (17) is arranged between the product cooler (16) and the screening device (18); The product cooler (16) includes a conical head (1601), a cylinder body (1602), a flat head (1603), a pipe orifice filter (1604), an agitator (1605), a cooling jacket (1606), and a cooler gas distributor (1607); the flat head (1603) is arranged at the upper port of the cylinder body (1602); the conical head (1601) is arranged at the lower port of the cylinder body (1602); the components of the agitator (1605) pass through the flat head (1603) and extend into the interior of the cylinder body (1602); the cooling jacket (1606) covers the outer surfaces of the conical head (1601) and the cylinder body (1602); the cooler gas distributor (1607) is arranged inside the lower end of the cylinder body (1602). The cylinder body (1602) of the product cooler (16) is further provided with a cooler feed port (N10), a cooler discharge port (N11), a cooler nitrogen inlet (N12), a cooler tail gas outlet (N13), a cooler cooling medium inlet (N14), and a cooler cooling medium outlet (N15). The cooler feed port (N10) is connected to the discharge port of the chemical vapor deposition rotary furnace (14) through a pipeline; the cooler discharge port (N11) is connected to the second screw conveyor (17); the outside of the cooler nitrogen inlet (N12) is connected to a nitrogen pipeline, and the inside is connected to the cooler gas distributor (1607); the cooler cooling medium inlet (N14) is connected to a cooling medium; the cooler tail gas outlet (N13) is connected to a heat recovery and utilization device through a pipeline; the pipe orifice filter (1604) is arranged in the cooler tail gas outlet (N13).

8. The preparation system of a gas-phase silicon-carbon anode material according to claim 7, characterized in that The heat recovery and utilization device includes a first heat exchanger (4), a second heat exchanger (11), a tail gas cooler (9), a condensate tank (10), a first filter (20), and a second filter (21); the tail gas outlet (N9) is sequentially connected to the first heat exchanger (4), the second heat exchanger (11), the tail gas cooler (9), the condensate tank (10), the first filter (20), and the second filter (21).

9. The preparation system of a gas-phase silicon-carbon anode material according to claim 7, wherein, It further includes a first heater (5), a second heater (6), a third heater (7), a fourth heater (12), a first mixer (8), and a second mixer (13). The nitrogen is divided into three paths in total. The first path of nitrogen is connected to the preheating bin (2) through a pipeline, and the second path of nitrogen is connected to the product cooler (16) through a pipeline; the third path of nitrogen is connected to the first heat exchanger (4) and the third heater (7) through a pipeline in sequence, and then is respectively connected to the inlets of the first mixer (8) and the second mixer (13). The silicon source gas is connected to the process gas preheating inlet (N5) through a pipeline, and after passing through the process gas preheating outlet (N6) pipeline and being connected to the first heater (5), it is connected to the inlet of the first mixer (8); when the silicon deposition reaction is carried out in the fluidized bed reactor (3), the silicon source gas and nitrogen are mixed in the first mixer (8) and enter the fluidized bed reactor (3). The carbon source gas is divided into two paths. The first path of the carbon source gas is connected to the process gas preheating inlet (N5) through a pipeline. After being connected to the second heater (6) through the pipeline of the process gas preheating outlet (N6), it is connected to the inlet of the first mixer (8). When the carbon coating reaction is carried out in the fluidized bed reactor (3), the carbon source gas and nitrogen are mixed in the first mixer (8) and enter the fluidized bed reactor (3); The second path of the carbon source gas is connected to the second heat exchanger (11) and the fourth heater (12) in sequence through pipelines, and then connected to the inlet of the second mixer (13); When the deep carbon coating reaction is carried out in the chemical vapor deposition rotary furnace (14), the carbon source gas and nitrogen are mixed in the second mixer (13) and enter the chemical vapor deposition rotary furnace (14); The outlet of the first mixer (8) is divided into two paths, which are respectively connected to the spouting gas inlet (N1) and the auxiliary fluidizing gas inlet (N2); The tail gas outlets of the preheating bin (2), the chemical vapor deposition rotary furnace (14) and the product cooler (16) are respectively collected through pipelines, and then flow into the tail gas cooler (9) through the first heat exchanger (4) and the second heat exchanger (11) in sequence.

10. A method for using a preparation system of a gas-phase silicon-carbon anode material according to any one of claims 1 to 9, characterized in that It includes the following steps: First, nitrogen from the gas raw material supply system is introduced into the solid raw material supply device, and the solid raw material is transported into the fluidized bed reactor (3); Secondly, a process gas composed of a silicon source gas and nitrogen is introduced into the fluidized bed reactor (3) to carry out a silicon deposition reaction with the solid raw material to obtain silicon carbide intermediate Ⅰ; Subsequently, the silicon source gas is stopped, and a process gas composed of a carbon source gas and nitrogen is introduced into the fluidized bed reactor (3) to carry out a carbon coating reaction with the silicon carbide intermediate Ⅰ to obtain silicon carbide intermediate Ⅱ; Next, nitrogen is introduced into the fluidized bed reactor (3) to transport the silicon carbide intermediate Ⅱ into the chemical vapor deposition rotary furnace (14), and then a process gas composed of a carbon source gas and nitrogen is introduced to carry out a deep carbon coating reaction to obtain a silicon carbide composite material; Subsequently, the obtained silicon carbide composite material is transported to the product post-treatment device for treatment to obtain a gaseous silicon carbide negative electrode material; During the reaction process, the waste heat generated by the solid raw material supply device, the fluidized bed reactor (3), the chemical vapor deposition rotary furnace (14) and the product post-treatment device is recovered by the waste heat recovery device.

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