CN117026200A - Device and method for producing nano silicon-carbon negative electrode material - Google Patents

Abstract

The application relates to the technical field of silicon-carbon negative electrode materials of lithium batteries, in particular to a nano silicon-carbon negative electrode material production device and a silicon-carbon negative electrode material production method. The nano silicon-carbon negative electrode material production device comprises a deposition furnace, wherein a sublimation chamber, a deposition chamber and a dust collection chamber are arranged in the deposition furnace, the sublimation chamber and the dust collection chamber are respectively communicated with the deposition chamber, and a heating assembly for respectively heating the sublimation chamber and the deposition chamber is arranged in a furnace body. The nano silicon-carbon negative electrode material production device can integrate the two procedures of preparation of silicon-based particles and carbon coating deposition, so that agglomeration of the silicon-based particles is reduced, and the obtained silicon-carbon negative electrode material is uniform in coating of a carbon layer, uniform in particle size and smaller in particle size.

Description

Nano silicon carbon negative electrode material production device and silicon carbon negative electrode material production method

Technical field

The present application relates to the technical field of silicon carbon negative electrode materials for lithium batteries, and more specifically, it relates to a production device for nano silicon carbon negative electrode materials and a production method of silicon carbon negative electrode materials.

Background technique

As the energy demand for new portable electronic products, electric vehicles and large-scale energy storage systems gradually increases, higher requirements are placed on the energy density of lithium-ion batteries. Silicon-based materials have become the mainstream direction for the development of next-generation anode materials due to their extremely high energy density, low delithiation potential and relatively excellent safety performance.

Since the silicon-based material itself is not conductive, it cannot be used directly as an anode material. During the charge and discharge process, the volume expansion rate of the silicon-based material is close to 300%, resulting in a low reversible capacity and poor cycle performance of the silicon-based anode material. Therefore, in order to improve the electrochemical performance and capacity of silicon-based anode materials, carbon materials with high conductivity and low expansion rate are usually used to surface modify the silicon-based materials to obtain silicon-carbon anode materials with good electrochemical performance and high capacity. .

At present, the preparation methods of silicon-carbon negative electrode materials include mechanical ball milling, high-temperature pyrolysis, CVD (chemical vapor deposition) and sol-gel. Among them, the CVD method is to pass carbon source gas into nanometer-scale In the silicon-based material powder, the carbon source gas reacts chemically, and then deposits to form deposited carbon coating on the surface of the nano-scale silicon-based material powder, thereby obtaining the silicon-carbon negative electrode material. However, the particle size of nano-scale silicon-based material powder is small and the specific surface area is large. The nano-scale silicon-based material powder is easy to agglomerate together, so that the deposited carbon cannot evenly coat the nano-scale silicon-based material powder. surface.

Contents of the invention

In order to improve the uniformity of deposited carbon-coated nanometer-sized silicon-based material powder, this application provides a nanometer silicon-carbon negative electrode material production device and a production method of silicon-carbon negative electrode material.

In the first aspect, this application provides a nano-silicon carbon negative electrode material production device, adopting the following technical solution:

A nano silicon carbon negative electrode material production device, including:

Deposition furnace, the deposition furnace is provided with a sublimation chamber, a deposition chamber and a dust collection chamber. The sublimation chamber and the dust collection chamber are respectively connected with the deposition chamber. The furnace body is provided with means for heating the sublimation chamber and the deposition chamber respectively. heating components;

The sublimation chamber is used to use a heating component to heat silicon-based material powder to generate silicon source gas;

The deposition chamber is used to use a heating component to heat the carbon source gas and the silicon source gas to produce chemical vapor deposition to generate silicon carbon anode material;

The dust collection room is used to collect silicon carbon negative electrode materials;

An air intake system, which is used to introduce carbon source gas and reducing gas into the deposition chamber;

A carrier gas system, which is used to introduce inert gas into the sublimation chamber;

Vacuum system, the vacuum system is used to evacuate the sublimation chamber, deposition chamber and dust collection chamber;

Cooling system, the cooling system is used to cool down the sublimation chamber, deposition chamber and dust collection chamber.

The working principle of the nano silicon carbon negative electrode material production device of this application is: first, the mixed powder containing metal silicon powder, silicon monoxide, and silicon dioxide is placed in the sublimation chamber as silicon-based material powder; and then maintained by the vacuum system The sublimation chamber, deposition chamber and dust collection chamber have a certain degree of vacuum, and inert gas is introduced into the sublimation chamber through the carrier gas system, so that the sublimation chamber, deposition chamber and dust collection chamber are filled with inert gas. Secondly, a heating component is used to heat the silicon-based material powder in the sublimation chamber to sublime the silicon source gas containing silicon vapor. Under the action of the inert gas flow, the silicon source gas in the sublimation chamber is promoted to enter the deposition chamber of a certain temperature, and condenses to form silicon-based particles that adhere to the deposition chamber. Third, the carbon source gas and reducing gas are introduced into the deposition chamber through the air inlet system. The carbon source gas is mixed with the silicon-based particles, and is thermally decomposed under the heating conditions of the heating component, and then is directly coated with a layer on the surface of the silicon-based particles. Carbon is deposited to form a silicon-carbon negative electrode material. Finally, the deposition chamber is cooled to room temperature under the cooling effect of the cooling system, causing the silicon carbon anode material to peel off from the deposition chamber, making it easier to collect the silicon carbon anode material.

At the same time, some unreacted carbon source gas, silicon source gas, and reducing gas can enter the dust collection chamber, continue to react, generate silicon carbon anode materials, and disperse in the dust collection chamber.

By adopting the above technical solution, the nano-silicon carbon negative electrode material production device of the present application can combine the two processes of silicon-based particle preparation and carbon deposition into one device, and on the one hand, because The silicon source gas can be directly condensed to form silicon-based particles that adhere to the deposition chamber, and the formed silicon-carbon negative electrode material needs to be condensed and cooled before being peeled off from the deposition chamber. This not only reduces the interaction force between adjacent silicon-based particles, but also It is necessary to mechanically strengthen the dispersed silicon-based particles; therefore, it is beneficial to reduce the agglomeration between silicon-based particles, improve the uniformity of the coating of the deposited carbon on the surface of the silicon-based particles, and obtain uniform coating, uniform particle size, high consistency, and good particle size. Silicon carbon anode materials below 30nm. On the other hand, the inert gas rushed into the sublimation chamber can promote the silicon source gas in the sublimation chamber to enter the deposition chamber for condensation deposition, increase the yield of silicon-based particles in the deposition chamber, and further increase the yield of the final silicon-carbon anode material. At the same time, the nano silicon carbon negative electrode material production device of this application avoids the waste of raw materials, the introduction of impurities and other unfavorable factors in the front and rear processes due to a series of reasons such as the transportation of raw materials and personnel operations.

Preferably, the carrier gas system includes a carrier gas tank and a gas delivery pipe. The carrier gas tank contains inert gas. The gas delivery pipe is connected to the carrier gas tank. One end of the gas delivery pipe away from the carrier gas tank runs through the dust collection chamber. and a deposition chamber connected to the sublimation chamber;

The air intake system includes a carbon source gas tank, a reducing gas tank and an air intake pipe. The carbon source gas tank and the reducing gas tank are respectively connected with the air intake pipe. The air intake pipe is far away from the carbon source gas tank and the reducing gas tank. One end runs through the sublimation chamber and is connected with the deposition chamber.

Preferably, the carrier gas system includes a carrier gas tank and a gas delivery pipe, the carrier gas tank contains inert gas, the gas delivery pipe is connected to the carrier gas tank, and one end of the gas delivery pipe away from the carrier gas tank is connected to the sublimation chamber. ;

The air intake system includes a carbon source gas tank, a reducing gas tank and an air intake pipe. The carbon source gas tank and the reducing gas tank are respectively connected with the air intake pipe. The air intake pipe is far away from the carbon source gas tank and the reducing gas tank. One end runs through the dust collection chamber and is connected with the sedimentation chamber.

By adopting the above technical solution, the inlet mode of inert gas, carbon source gas and reducing gas in the deposition furnace is controlled. Under the action of the flow of inert gas, the silicon source gas is promoted to enter the deposition chamber for condensation, which is beneficial to improving the silicon base. Material yield.

Preferably, the furnace body is provided with a graphite plate located between the sublimation chamber and the deposition chamber, and a vent hole is provided on the surface of the graphite plate.

By adopting the above technical solution, the silicon source gas sublimated out of the sublimation chamber can enter the deposition chamber along the vent hole for condensation. At the same time, the graphite plate is a good refractory and insulating material, which can effectively isolate the heat transfer between the sublimation chamber and the deposition chamber, improve the condensation effect of silicon source gas in the deposition chamber, and improve the decomposition effect of carbon source gas in the deposition chamber.

Preferably, a deposition part for collecting silicon carbon negative electrode material is provided in the deposition chamber, and the deposition part is detachably connected to the graphite plate or the top of the deposition chamber.

By adopting the above technical solution, the deposition parts can be vertically fixed or suspended in the deposition chamber, which is conducive to full contact between the deposition parts and the silicon source gas or carbon source gas, reducing the agglomeration of silicon-based particles, and obtaining uniform coating, uniform particle size, and consistency. High silicon carbon anode material.

Preferably, the deposition member is a deposition plate or a deposition tube.

By adopting the above technical solution, the deposition plate and the deposition tube are smaller in size and can be easily disassembled and assembled in the deposition chamber.

Preferably, the deposition furnace includes a furnace body, an upper furnace cover and a lower furnace cover, the upper furnace cover is detachably provided at the top of the upper furnace body, and the lower furnace cover is detachably provided at the bottom of the furnace body;

The nano silicon carbon negative electrode material production device also includes a lifting system, which is fixedly installed on the lower furnace cover and used to drive the lower furnace cover and sublimation chamber to separate or combine with the furnace body.

By adopting the above technical solution, the lifting system can drive the lower furnace cover, sublimation chamber and furnace body to separate, making it easier to load and unload materials in the sublimation chamber, and improving the convenience of loading and unloading the device.

Preferably, the lifting system includes a support frame and a plurality of sliding blocks. The support frame is erected around the lower furnace cover. The plurality of sliding blocks and the lower furnace cover are detachably arranged. The support frame is provided with a The driving member that drives the sliding block to slide up and down on the support frame.

By adopting the above technical solution, multiple sliding blocks can improve the stability of the lower furnace cover and sublimation chamber when the support frame is raised and lowered, and improve the safety of loading and unloading of the device.

In the second aspect, this application provides a production method of a silicon carbon negative electrode material production device, adopting the following technical solution:

A production method of a silicon carbon negative electrode material production device, including the following steps:

S1: Place the silicon-based material in the sublimation chamber, first use a vacuum system to control the vacuum degree of the sublimation chamber, deposition chamber and dust collection chamber, and then use a carrier gas system to pass inert gas into the sublimation chamber;

S2: Use a heating component to heat the sublimation chamber so that the silicon source gas sublimates out of the sublimation chamber, and the inert gas can carry the silicon source gas to the deposition chamber; then use a cooling system to adjust the temperature of the deposition chamber so that the silicon source gas condenses to form silicon base particles;

S3: Use a heating component to heat the deposition chamber, and pass the carbon source gas and reducing gas into the deposition chamber along the air inlet pipe to maintain heat. The carbon source gas will undergo vapor-phase chemical deposition on the surface of the silicon-based particles to form a silicon-carbon anode material;

S4: Use a cooling system to adjust the temperature of the deposition chamber to peel off the silicon carbon anode material in the deposition chamber and collect the silicon carbon anode material;

Among them, the flow rate of inert gas is 15-24L/min, and the pressure is 1-10kPa;

The flow rate of carbon source gas is 1-10L/min, and the pressure is 2-5kPa;

The flow rate of reducing gas is 1-10L/min, and the pressure is 2-5kPa.

By adopting the above technical solution, the inert gas enters the sublimation chamber as a protective gas and a carrying gas, carrying the sublimated silicon source gas into the deposition chamber, where it condenses to form a large number of silicon-based particles; at the same time, the carbon source gas directly enters the deposition chamber, It is thermally decomposed and undergoes a vapor-phase chemical deposition reaction. A layer of deposited carbon is coated on the surface of the silicon-based particles. After condensation and peeling, a silicon-carbon anode material with uniform coating, uniform particle size, high consistency, and a particle size of less than 30nm can be obtained. .

To sum up, this application has the following beneficial effects:

The nano-silicon carbon anode material production device of this application can combine the two processes of silicon-based particle preparation and carbon deposition into one device. On the one hand, there is no need to mechanically strengthen the dispersed silicon-based particles. , avoiding the agglomeration of silicon-based particles when dispersing silicon-based particles, and improving the coating uniformity of the carbon layer on the surface of the nano-silicon carbon negative electrode material; on the other hand, the inert gas can be used as a carrying gas to carry the silicon source gas in the sublimation chamber into the deposition chamber Condensation deposition increases the number of silicon-based particles in the deposition chamber, which is beneficial to increasing the yield of the final silicon-carbon anode material.

Description of the drawings

Figure 1 is a schematic diagram of the overall structure of a nano-silicon carbon negative electrode material production device in Example 1 of the present application;

Figure 2 is a schematic cross-sectional structural diagram of the deposition furnace in Embodiment 1 of the present application;

Figure 3 is a partial cross-sectional structural diagram of the furnace body, upper furnace cover, and lower furnace cover in Embodiment 1 of the present application;

Figure 4 is a partial cross-sectional structural schematic diagram of the deposition furnace in Embodiment 1 of the present application;

Figure 5 is a schematic diagram of the overall structure of the lifting system in Embodiment 1 of the present application;

Figure 6 is a partial cross-sectional structural diagram of the deposition furnace in Embodiment 2 of the present application.

Reference signs: 1. Deposition furnace; 101. Furnace body; 102. Upper furnace cover; 103. Lower furnace cover; 2. Sublimation chamber; 3. Deposition chamber; 4. Dust collection chamber; 5. Heating component; 6. Inlet gas system; 601, carbon source gas tank; 602, reducing gas tank; 603, air inlet pipe; 7, carrier gas system; 701 carrier gas tank; 702, gas pipe; 8, vacuum system; 801, vacuum pump; 802, suction Air pipe; 9. Cooling system; 901. Return water tank; 902. Water pipe; 903. Return pipe; 10. Graphite plate; 11. Ventilation hole; 12. Deposition parts; 13. Lifting system; 1301. Support frame; 1302. Sliding block; 1303, driving parts; 14, exhaust system; 1401, exhaust burner; 1402, bag dust collector; 15, cavity; 16, bottom plate; 17, crucible; 18, fixed plate; 19, sleeve; 20 , support block; 21. Insulation layer; 22. Receiving box; 23. Box cover; 24. Through hole; 25. Partition plate; 26. Dust collection box; 27. Avoidance tube; 28. Screw; 29. Limit Rod; 30. Connecting plate.

Detailed ways

The present application will be further described in detail below in conjunction with the accompanying drawings and examples.

Example

Example 1

A nano silicon carbon negative electrode material production device, with reference to Figures 1 and 2, includes a deposition furnace 1, an air intake system 6, a carrier gas system 7, a vacuum system 8, an exhaust system 14, a cooling system 9 and a lifting system 13. The deposition furnace 1 is provided with a sublimation chamber 2, a deposition chamber 3 and a dust collection chamber 4 that are interconnected. After the silicon-based material powder is placed in the sublimation chamber 2, the sublimation chamber 2 is heated to sublimate the silicon source gas. The gas inlet system 6 can introduce carbon source gas and reducing gas into the deposition chamber 3; the carrier gas system 7 can introduce inert gas into the sublimation chamber 2. Therefore, the silicon source gas can quickly enter the deposition chamber 3 under the action of the inert gas flow, and condense to form silicon-based particles that adhere to the deposition chamber 3, which reduces the agglomeration of the silicon-based particles and is conducive to being heated in the deposition chamber 3. The decomposed carbon source gas is coated to obtain a silicon-carbon negative electrode material with uniform particle size, high consistency, and uniform carbon coating layer thickness.

Referring to Figures 1 and 2, the deposition furnace 1 includes a furnace body 101, an upper furnace cover 102 and a lower furnace cover 103. The upper furnace cover 102 is sealed on the top of the upper furnace body 101 through flanges, and the lower furnace cover 103 is sealed on the top of the furnace through flanges. Body 101 bottom. The furnace body 101, the upper furnace cover 102 and the lower furnace cover 103 are all provided with cavities 15. The furnace body 101, the upper furnace cover 102 and the lower furnace cover 103 are all provided with water inlet pipes and water outlet pipes interconnected with the cavity 15. .

Referring to Figures 2 and 3, a bottom plate 16 located in the furnace body 101 is fixed on the lower furnace cover 103. The bottom plate 16 is perpendicular to the central axis of the furnace body 101, and a crucible 17 is placed on the bottom plate 16. A fixed plate 18 is fixedly provided in the furnace body 101. A graphite plate 10 located on the top of the crucible 17 is fixed on the fixed plate 18 with bolts. The graphite plate 10 abuts the top of the crucible 17 and forms a sublimation chamber 2. There are openings on the surface of the graphite plate 10. There are multiple ventilation holes 11. The silicon-based material powder can be placed in the crucible 17 for high-temperature heating to sublimate the carbon source gas.

Referring to FIG. 4 , a sleeve 19 is vertically fixed on the side of the graphite plate 10 away from the fixed plate 18 . The graphite plate 10 and the sleeve 19 form the deposition chamber 3 . The graphite plate 10 is provided with a deposition part 12 located in the deposition chamber 3. In the embodiment of the present application, the deposition part 12 is a deposition plate, and a support block 20 is fixed at the bottom of the deposition plate. The support block 20 is vertically fixed on the graphite plate through bolts. 10 on. The carbon source gas sublimated in the sublimation chamber 2 enters the deposition chamber 3 along the vent hole 11 and condenses to form silicon-based particles that adhere to the surface of the deposition plate, which is beneficial to reducing the agglomeration of the silicon-based particles.

The crucible 17 and the sleeve 19 are each equipped with an independent heating component 5. In the embodiment of the present application, the heating component 5 is an induction coil. The induction coils set on the crucible 17 and the sleeve 19 are made of special-shaped copper tubes. They can control the temperatures of the sublimation chamber 2 and the deposition chamber 3 respectively under energized conditions, which is beneficial to the deposition of silicon-based material powder. Sublimation occurs in the sublimation chamber 2, and the carbon source gas is thermally decomposed in the deposition chamber 3 to obtain a silicon carbon anode material with uniform coating, uniform particle size, and high consistency.

The inner walls of the furnace body 101, the upper furnace cover 102 and the lower furnace cover 103 are all fixed with an insulation layer 21. In the embodiment of the present application, the insulation layer 21 is an insulation felt. The thermal insulation felt can reduce heat loss in the crucible 17 and the sleeve 19 and save energy consumption.

The end of the sleeve 19 away from the graphite plate 10 is fixed with a collection box 22 through bolts. The top of the collection box 22 is sealed with a box cover 23 through a flange. The collection box 22 and the box cover 23 form a dust collection chamber 4 . The bottom of the material receiving box 22 is provided with a through hole 24 interconnected with the deposition chamber 3 . Part of the silicon source gas in the deposition chamber 3 can enter the dust collection chamber 4 along the through hole 24 and condense into silicon-based particles that adhere to the dust collection chamber 4 . Part of the thermally decomposed carbon source gas in the deposition chamber 3 can enter the dust collection chamber 4 along the through hole 24, and coat the surface of the silicon-based particles with a layer of deposited carbon to form a silicon-carbon negative electrode material, which is beneficial to improving the utilization rate of raw materials.

A partition 25 is fixedly installed in the material collection box 22 and the partition 25 and the bottom of the material collection box 22 are parallel to each other. A dust collecting box 26 is fixed inside the material collecting box 22 by bolts, and the dust collecting box 26 and the dust collecting chamber 4 are connected with each other. The dust collection box 26 is located below the partition 25 and is perpendicular to the bottom of the material collection box 22 . The dust collection box 26 can increase the area of the dust collection chamber 4 to accommodate silicon carbon negative electrode materials and/or silicon-based particles.

Referring to Figures 1 and 4, the carrier gas system 7 includes a carrier gas tank 701 and a gas delivery pipe 702. The gas delivery pipe 702 is connected to the carrier gas tank 701. The carrier gas tank 701 contains an inert gas, which may be nitrogen or argon. In the embodiment of the present application, the inert gas is nitrogen. The end of the gas transmission pipe 702 away from the carrier gas tank 701 penetrates the upper furnace cover 102, the box cover 23, the partition 25, the material receiving box 22, and is connected with the sublimation chamber 2. Open the valve on the carrier gas tank 701, and the inert gas flows into the deposition chamber 3 and the dust collection chamber 4 through the gas pipe 702 along the sublimation chamber 2, maintaining the inert gas environment in the sublimation chamber 2, the deposition chamber 3 and the dust collection chamber 4.

Referring to FIGS. 1 and 4 , the air intake system 6 includes a carbon source gas tank 601 , a reducing gas tank 602 and an air intake pipe 603 . The carbon source gas tank 601 and the reducing gas tank 602 are respectively connected with the air intake pipe 603 . An escape tube 27 is fixedly provided in the middle of the crucible 17 . The air inlet pipe 603 is away from the carbon source gas tank 601 and one end of the reducing gas tank 602 penetrates the upper and lower furnace covers 103, the bottom plate 16 and the escape tube 27, and is connected to the deposition chamber 3. After the carbon source gas and the reducing gas enter the gas mixing tank and are mixed, they are passed into the deposition chamber 3 along the air inlet pipe 603, and undergo vapor-phase chemical deposition with the silicon-based particles adhered in the deposition chamber 3 to generate silicon-carbon negative electrode materials.

In this application, the carbon source gas in the carbon source gas tank 601 may be one or more hydrocarbon gases such as natural gas, propylene gas, propane gas, acetylene gas, etc.; the reducing gas in the reducing gas tank 602 may be One of hydrogen and carbon monoxide. In the embodiment of the present application, the carbon source gas is natural gas and the reducing gas is hydrogen.

Referring to Figures 1 and 4, the vacuum system 8 includes a vacuum pump 801 and a suction pipe 802. The suction pipe 802 is connected with the air inlet of the vacuum pump 801. The suction pipe 802 penetrates the upper furnace cover 102, the box cover 23, the partition 25 and is located above the dust collection box 26.

Referring to Figure 1, the exhaust system 14 includes an exhaust burner 1401 and a bag dust collector 1402. The exhaust burner 1401 is connected to the air outlet of the vacuum pump 801 and the bag dust collector 1402 respectively. After the burner burns the combustible gas extracted from the vacuum pump 801, the dust is removed by the bag dust collector 1402 and then directly discharged.

Referring to Figures 1 and 3, the cooling system 9 includes a return water tank 901, a water delivery pipe 902 and a return water pipe 903. The return water tank 901 is connected to the water delivery pipe 902 and the return water pipe 903 respectively. The return tank 901 is provided with a driving device that drives the cooling water to circulate. The return water tank 901 is connected to the water inlet pipe and the nozzle of the special-shaped copper pipe respectively through the water delivery pipe 902, and the return water tank 901 is connected to the water outlet pipe and the other nozzle of the special-shaped copper pipe respectively through the return pipe 903. After the induction coil is powered off, driven by the driving device of the return water tank 901, the water delivery pipe 902 passes the cooling water in the return water tank 901 into the cavity 15 and the special-shaped copper tube for heat exchange and cooling. The return water pipe 903 then passes the empty The water used for heat exchange and cooling in the cavity 15 and the special-shaped copper tube flows back into the return water tank 901, so that the return water tank 901 forms a circulating return flow with the cooling water in the cavity 15 and the special-shaped copper tube, respectively, and can be connected to the upper furnace cover 102 respectively. , the furnace body 101, the lower furnace cover 103 and the induction coil are cooled down to facilitate the condensation of the silicon source gas and the peeling off of the silicon carbon negative electrode material.

Referring to Figures 4 and 5, the lifting system 13 includes a support frame 1301, a screw rod 28, a sliding block 1302 and a driving member 1303. In the embodiment of the present application, the driving member 1303 is a motor, and the motor is fixedly installed on the top of the support frame 1301, and the wire One end of the rod 28 is fixed on the output shaft of the motor, and the end of the screw rod 28 away from the motor is fixed on the bottom of the support frame 1301 through a bearing. The support frame 1301 is fixed with a limiting rod 29 that is parallel to the screw rod 28 . The sliding block 1302 is respectively sleeved on the screw rod 28 and the limiting rod 29 , and is connected to the screw rod 28 through the screw rod 28 nut. The sliding block 1302 is provided with a connecting plate 30 fixed by bolts, and the end of the connecting plate 30 away from the sliding block 1302 is connected to the lower furnace cover 103 by bolts. Turn on the motor, and the motor can drive the screw rod 28 to rotate, so that the sliding block 1302 slides on the screw rod 28 and the limit rod 29, and the lower furnace cover 103, the sublimation chamber 2 and the furnace body 101 can be separated or combined to facilitate sublimation. Loading and unloading materials in room 2.

The implementation principle of a nano-silicon carbon negative electrode material production device in the embodiment of the present application is as follows: first, the lower furnace cover 103 and the crucible 17 are separated from the furnace body 101 by driving the motor, and the silicon-based material powder is placed in the crucible 17, and then the lower furnace lid 103 and the crucible 17 are driven by the motor. The furnace cover 103 and the crucible 17 are combined with the furnace body 101 and sealed; then a vacuum pump 801 is used to evacuate, and nitrogen is introduced into the sublimation chamber 2 through a gas pipe 702. Secondly, an induction coil is used to heat the crucible 17 to sublimate the silicon source gas containing silicon vapor; the silicon source gas enters the deposition chamber 3 along the vent hole 11 under the action of nitrogen gas flow, condenses and adheres to the deposition plate. Again, an induction coil is used to heat the sleeve 19, and the carbon source gas and the reducing gas are introduced into the deposition chamber 3 along the inlet pipe 603, so that the carbon source gas decomposes and coats the surface of the silicon-based particles with a layer of deposited carbon. Form silicon carbon negative electrode material. Finally, the cooling water in the return water tank 901 circulates in the furnace body 101, the upper furnace cover 102, the lower furnace cover 103 and the special-shaped copper tube, reducing the temperature in the deposition chamber 3, causing the silicon carbon anode material to peel off from the deposition plate. Convenient to collect silicon carbon anode materials.

Example 2

A nano-silicon carbon negative electrode material production device is different from Embodiment 1 in that, referring to Figure 6, the deposition part 12 is a deposition tube. There are ventilation holes on the surface of the deposition tube. The deposition tube is fixedly arranged on the support block 20. The support The block 20 is fixed at the bottom of the receiving box 22 by bolts, so that the deposition tube is suspended in the deposition chamber 3, which is conducive to the full contact reaction of the silicon source gas and the carbon source gas on the surface of the deposition tube to obtain uniform particle size, high consistency, and carbon Silicon carbon anode material with uniform coating thickness. At the same time, in the embodiments of the present application, the silicon source gas can not only condense on the surface of the deposition tube, but also condense on the inner wall of the deposition tube through the ventilation holes, which is beneficial to improving the yield of silicon-based particles.

In the carrier gas system 7 , the end of the gas delivery pipe 702 away from the carrier gas tank 701 penetrates the lower furnace cover 103 , the bottom plate 16 and the escape tube 27 , and is connected to the sublimation chamber 2 . In the air inlet system 6 , the end of the air inlet pipe 603 away from the gas mixing tank penetrates the upper furnace cover 102 , the box cover 23 , the partition 25 and the material receiving box 22 , and is connected to the deposition chamber 3 . The inert gas flushed out of the gas pipe 702 can flush the silicon source gas in the sublimation chamber 2 into the deposition chamber 3, which is beneficial to improving the yield of silicon-based particles.

Example 3

A nano-silicon carbon negative electrode material production device is different from Embodiment 2 in that the deposition part 12 is a deposition plate.

Example 4

A nano-silicon carbon negative electrode material production device is different from Embodiment 1 in that the deposition part 12 is a deposition tube.

Example 5

A nano silicon carbon negative electrode material production device is different from Embodiment 1 in that the air inlet pipe 603 is far away from the carbon source gas tank 601 and one end of the reducing gas tank 602 penetrates through the upper furnace cover 102, the box cover 23, the partition The plate 25 and the receiving box 22 are connected with the sublimation chamber 2.

Example 6

A production method for producing silicon carbon negative electrode material by a nanometer silicon carbon negative electrode material production device, which is produced by using the nanometer silicon carbon negative electrode material production device of Embodiment 1.

The above production method, with reference to Figure 1, Figure 2 and Figure 5, includes the following steps:

S1: Turn on the motor, drive the sliding block 1302 to slide on the screw rod 28 and the limit rod 29, so that the lower furnace cover 103 and the crucible 17 are separated from the furnace body 101; place the silicon-based material powder in the crucible 17, and then pass the motor Drive the lower furnace cover 103 and crucible 17 to combine with the furnace body 101 and use flange sealing; turn on the vacuum pump 801, and control the vacuum degree of the sublimation chamber 2, deposition chamber 3 and dust collection chamber 4 through the suction pipe 802 to 5000-1000Pa ( 5000Pa in the embodiment of the present application), and then pass nitrogen with a flow rate of 15-24L/min (15L/min in the embodiment of the present application) and a pressure of 1-10kPa (1kPa in the embodiment of the present application) through the gas pipe 702 into the sublimation Room 2.

S2: Use an induction coil to heat the crucible 17 to 1000-1400°C (1000°C in this embodiment), where the heating time is 1-3h (1h in this embodiment), so that the silicon contained in the sublimation chamber 2 is sublimated. The silicon source gas of steam; the silicon source gas enters the deposition chamber 3 along the vent hole 11 under the action of the nitrogen gas flow; the cooling water in the return water tank 901 is driven to circulate in the furnace body 101, the upper furnace cover 102, the lower furnace cover 103 and the sleeve 19 circulates in the special-shaped copper tube outside, where the temperature of the cooling water is 20-25°C, the cooling water circulation time is 1-5h (4h in the embodiment of this application), and the temperature in the deposition chamber 3 is reduced, so that the deposition chamber 3 The silicon source gas in the vapor condenses to form silicon-based particles and adhere to the deposition plate.

S3: Use an induction coil to heat the sleeve 19 to 600-1300°C (1200°C in the embodiment of this application), set the flow rate to 1-10L/min (5L/min in the embodiment of this application), and set the pressure to 2-5kPa (The embodiment of the present application is 2kPa) carbon source gas, the flow rate is 1-10L/min (the embodiment of the present application is 5L/min), the pressure is 2-5kPa (the embodiment of the present application is 2kPa) reducing gas, along the The air inlet pipe 603 is led into the deposition chamber 3 and kept warm for 1-48 hours (5 hours in the embodiment of this application), so that the carbon source gas decomposes and coats the surface of the silicon-based particles with a layer of deposited carbon to form a silicon-carbon negative electrode material.

S4: The cooling water in the drive return tank 901 circulates in the furnace body 101, the upper furnace cover 102, the lower furnace cover 103 and the special-shaped copper tube outside the sleeve 19. The temperature of the cooling water is 20-25°C. The water circulation time is 1-5 hours (4 hours in the embodiment of this application). The temperature in the deposition chamber 3 is lowered to promote the silicon carbon negative electrode material to peel off from the deposition plate, and the silicon carbon negative electrode material is collected.

Conduct Raman spectra detection on silicon carbon anode materials. The test results show that the ratio of the two peak intensities, ID/IG, is 2, which shows that the silicon carbon anode material of the present application has high density.

The specific surface area (SSA) of the silicon carbon anode material was detected through N ₂ physical adsorption and the Brunauer-Emmette Teller (BET) method. The test results show that the silicon carbon anode material in the embodiment of the present application meets the requirement for commercial products that the SSA is less than 2 m ² /g, which shows that the carbon layer of the silicon carbon anode material in the embodiment of the present application is densely coated.

In the production method of silicon carbon negative electrode material produced by the nano silicon carbon negative electrode material production device of the present application, when the temperature, time, vacuum degree and gas flow are within the above range, the performance of the silicon carbon negative electrode material is the same as that in Example 5. Therefore, this application only briefly describes the temperature, time, vacuum degree and gas flow rate of Example 5 as examples, but this does not affect the application of other temperatures, times, vacuum degrees and gas flow rates claimed in this application in this application. .

Comparative example 1

A method for producing silicon carbon negative electrode material using a silicon carbon negative electrode material production device. The difference from Example 6 is that the nanometer silicon carbon negative electrode material production device of Example 5 is used for production.

Conduct Raman spectra detection on silicon carbon anode materials. The test results show that the ratio of the two peak intensities, ID/IG, is 1.5, which shows that the silicon carbon anode material in the comparative example of the present application has low density.

The specific surface area (SSA) of the silicon carbon anode material was detected through N ₂ physical adsorption and the Brunauer-Emmette Teller (BET) method. The test results show that the silicon carbon anode material in the embodiment of the present application does not meet the requirement of commercial products that the SSA is less than 2 m ² /g, which shows that the carbon layer coating density of the silicon carbon anode material is low.

This specific embodiment is only an explanation of the present application, and it is not a limitation of the present application. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contribution as needed, but as long as the rights of this application are All requirements are protected by patent law.

Claims (9)

1. A nano-silicon carbon negative electrode material production device, characterized in that it includes: Deposition furnace (1). The deposition furnace (1) is provided with a sublimation chamber (2), a deposition chamber (3) and a dust collection chamber (4). The sublimation chamber (2) and dust collection chamber (4) are respectively Communicated with the deposition chamber (3), the furnace body (101) is provided with heating components (5) for heating the sublimation chamber (2) and the deposition chamber (3) respectively; The sublimation chamber (2) is used to heat silicon-based material powder using a heating component (5) to generate silicon source gas; The deposition chamber (3) is used to use a heating assembly (5) to heat the carbon source gas and the silicon source gas to cause chemical vapor deposition to generate silicon carbon anode material; The dust collection chamber (4) is used to collect silicon carbon negative electrode materials; An air intake system (6), which is used to introduce carbon source gas and reducing gas into the deposition chamber (3); Carrier gas system (7), the carrier gas system (7) is used to introduce inert gas into the sublimation chamber (2); Vacuum system (8), the vacuum system (8) is used to evacuate the sublimation chamber (2), deposition chamber (3) and dust collection chamber (4); Cooling system (9), the cooling system (9) is used to cool down the sublimation chamber (2), the deposition chamber (3) and the dust collection chamber (4). 2. The nano silicon carbon negative electrode material production device according to claim 1, characterized in that the carrier gas system (7) includes a carrier gas tank (701) and a gas delivery pipe (702), and the carrier gas tank (701 ) contains inert gas, the gas pipe (702) is connected with the carrier gas tank (701), and the end of the gas pipe (702) away from the carrier gas tank (701) runs through the dust collection chamber (4) and the deposition chamber (3 ) and connected with the sublimation chamber (2); The air intake system (6) includes a carbon source gas tank (601), a reducing gas tank (602) and an air intake pipe (603). The carbon source gas tank (601) and the reducing gas tank (602) are respectively connected with The air inlet pipe (603) is connected. One end of the air inlet pipe (603) away from the carbon source gas tank (601) and the reducing gas tank (602) penetrates the sublimation chamber (2) and is connected with the deposition chamber (3). 3. The nano silicon carbon anode material production device according to claim 1, characterized in that the carrier gas system (7) includes a carrier gas tank (701) and a gas delivery pipe (702), and the carrier gas tank (701 ) contains inert gas, the gas pipe (702) is connected to the carrier gas tank (701), and the end of the gas pipe (702) away from the carrier gas tank (701) is connected to the sublimation chamber (2); The air intake system (6) includes a carbon source gas tank (601), a reducing gas tank (602) and an air intake pipe (603). The carbon source gas tank (601) and the reducing gas tank (602) are respectively connected with The air inlet pipe (603) is connected. One end of the air inlet pipe (603) away from the carbon source gas tank (601) and the reducing gas tank (602) penetrates the dust collection chamber (4) and is connected with the deposition chamber (3). 4. The nano-silicon carbon negative electrode material production device according to claim 1, characterized in that a graphite plate (10) located between the sublimation chamber (2) and the deposition chamber (3) is provided in the furnace body (101). ), and ventilation holes (11) are provided on the surface of the graphite plate (10). 5. The nano-silicon carbon anode material production device according to claim 4, characterized in that a deposition part (12) for collecting silicon carbon anode material is provided in the deposition chamber (3), and the deposition part (12) ) is detachably connected to the graphite plate (10) or the top of the deposition chamber (3). 6. The nano-silicon carbon negative electrode material production device according to claim 5, characterized in that the deposition part (12) is a deposition plate or a deposition tube. 7. The nano silicon carbon negative electrode material production device according to claim 1, characterized in that the deposition furnace (1) includes a furnace body (101), an upper furnace cover (102) and a lower furnace cover (103), so The upper furnace cover (102) is detachably installed on the top of the upper furnace body (101), and the lower furnace cover (103) is detachably installed on the bottom of the furnace body (101); The nano silicon carbon negative electrode material production device also includes a lifting system (13). The lifting system (13) is fixedly installed on the lower furnace cover (103) and is used to drive the lower furnace cover (103) and the sublimation chamber (2). Detach or combine with the furnace body (101). 8. The nano silicon carbon negative electrode material production device according to claim 7, characterized in that the lifting system (13) includes a support frame (1301) and a plurality of sliding blocks (1302), and the support frame (1301 ) is erected on the peripheral side of the lower furnace cover (103), a plurality of sliding blocks (1302) and the lower furnace cover (103) are detachably arranged, and a driving sliding block (1302) is provided on the support frame (1301). The driving member (1303) for sliding and lifting on the support frame (1301). 9. The production method for producing silicon carbon negative electrode material by the nano silicon carbon negative electrode material production device according to any one of claims 1 to 8, characterized in that it includes the following steps: S1: Place the silicon-based material in the sublimation chamber (2), first use the vacuum system (8) to control the vacuum degree of the sublimation chamber (2), deposition chamber (3) and dust collection chamber (4), and then use the carrier gas system (7) Pass the inert gas into the sublimation chamber (2); S2: Use the heating component (5) to heat the sublimation chamber (2), so that the silicon source gas is sublimated out of the sublimation chamber (2), and the inert gas can carry the silicon source gas to the deposition chamber (3); then use a cooling system (9) Adjust the temperature of the deposition chamber (3) so that the silicon source gas condenses to form silicon-based particles; S3: Use the heating component (5) to heat the deposition chamber (3), and pass the carbon source gas and reducing gas into the deposition chamber (3) along the inlet pipe (603) to maintain heat. The carbon source gas is on the surface of the silicon-based particles. Vapor phase chemical deposition occurs to form silicon carbon anode material; S4: Use the cooling system (9) to adjust the temperature of the deposition chamber (3), causing the silicon carbon anode material in the deposition chamber (3) to peel off, and collect the silicon carbon anode material; Among them, the flow rate of inert gas is 15-24L/min, and the pressure is 1-10kPa; The flow rate of carbon source gas is 1-10L/min, and the pressure is 2-5kPa; The flow rate of reducing gas is 1-10L/min, and the pressure is 2-5kPa.