CN108269989B - Carbon-coated micron silicon, and preparation method and application thereof - Google Patents

Carbon-coated micron silicon, and preparation method and application thereof Download PDF

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CN108269989B
CN108269989B CN201810135903.9A CN201810135903A CN108269989B CN 108269989 B CN108269989 B CN 108269989B CN 201810135903 A CN201810135903 A CN 201810135903A CN 108269989 B CN108269989 B CN 108269989B
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silicon
carbon dioxide
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magnesium silicide
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CN108269989A (en
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霍开富
高标
项奔
安威力
付继江
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Wuhan University of Science and Engineering WUSE
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H01M4/366—Composites as layered products
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H01M4/386—Silicon or alloys based on silicon
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

The invention discloses a carbon-coated micron silicon, and a preparation method and application thereof, belonging to the technical field of inorganic material preparation. The preparation method is simple and easy to implement, can be used for producing large-scale carbon-coated micron silicon, and solves the technical problems that the preparation process of the carbon-coated micron silicon material in the prior art is complex, poor in safety and not beneficial to large-scale production and application.

Description

Carbon-coated micron silicon, and preparation method and application thereof
Technical Field
The invention belongs to the technical field of inorganic material preparation, and particularly relates to carbon-coated micron silicon, and a preparation method and application thereof.
Background
In recent years, with the development of new energy technologies, electronic devices are developing towards intelligent portability, requirements on battery technologies are higher and higher, the capacity of batteries is higher, and electrochemical performance is stable. Therefore, the high specific energy lithium ion battery industry is produced. The negative electrode material used in lithium ion batteries is one of the key factors determining the performance of lithium ion batteries. At present, the lithium ion battery negative electrode materials are mainly carbon materials and non-carbon materials, in the non-carbon negative electrode materials, the silicon materials have high theoretical lithium storage capacity (4200mA h/g) which is 11 times of the commercial graphite negative electrode theoretical capacity, and the voltage platform of Si is slightly higher than that of graphite, so that the phenomenon of surface lithium precipitation is not easily caused during charging, and the safety performance is high. However, silicon as a semiconductor material faces a problem of poor conductivity in lithium ion batteries, and the silicon material undergoes severe volume expansion (volume change rate between 300% and 400%) when lithium is deintercalated during charge and discharge. These seriously affect the coulombic efficiency and cycle stability of the battery, and hinder the development of commercialization thereof.
The problems of silicon materials in lithium ion batteries are solved, and a composite method is generally adopted. The silicon-carbon negative electrode mainly reported in the current market or literature is simply mixed of nano-silicon and graphite, or the nano-silicon is attached to the surface of the graphite and then certain subsequent treatment is carried out. But this still can not avoid the electrode material from expanding and causing the whole inflation of electrode, thus bring the safety accident. For example: CN103474667A discloses a silicon-carbon composite material and a preparation method thereof, which adopts nano-silicon and graphite to mix, then CVD coats a layer of carbon, then liquid phase coats a layer of carbon, and finally crushing to obtain a final product. As another example, in "a low expansion rate porous silicon/graphite composite electrode material and a method for preparing the same" (CN106784743A), a dealloying method is used to obtain porous silicon, and then carbon coating is performed or the porous silicon/graphite composite electrode material is directly mixed with a commercial graphite negative electrode to obtain a final porous silicon/graphite composite material, but dealloying is a chemical etching method, and the carbon coating process increases a preparation process, which limits industrial applications. As another example, in the patent, "a composite carbon-coated porous silicon negative electrode material and a preparation method thereof" (CN106935834A) based on dealloyed porous silicon, a double-layer carbon coating is achieved by coating a composite carbon layer in which graphene is combined with high-density carbon or low-density carbon is combined with high-density carbon, and the finally obtained product has good cycle performance, but the silicon-carbon composite material obtained by the method needs to perform two carbon coating processes, the preparation procedure is complicated, and dealloying adopts a chemical corrosion method, which is not favorable for industrial production; the document "SiO Synthesis of Si nanoparticles using magnesium nitride reduction and itscarbon composite as a high-performance and for Li ion batteries" reports2With Mg2Si reacts to obtain porous silicon, then the porous silicon is mixed with PVA, the silicon-carbon composite material of carbon-coated porous silicon is obtained after carbonization, and the obtained silicon-carbon composite material has good cycle performanceHowever, HCl and HF are used for washing reaction products, which is highly corrosive and not beneficial to industrial production.
Disclosure of Invention
The invention provides a carbon-coated porous micron silicon, a preparation method and application thereof, aiming at solving the technical problems that the preparation process of the carbon-coated micron silicon material is complex, the safety is poor and the carbon-coated micron silicon material is not beneficial to large-scale production and application.
In order to achieve the above object, according to one aspect of the present invention, there is provided a method for preparing carbon-coated micro silicon, comprising the steps of:
(1) taking magnesium silicide as a raw material, and reacting for 2-24 hours at 400-800 ℃ in an atmosphere containing carbon dioxide to obtain a crude product containing magnesium oxide and carbon-coated silicon; the atmosphere containing carbon dioxide is carbon dioxide atmosphere or mixed atmosphere of carbon dioxide and inert gas;
(2) and (2) carrying out acid washing treatment on the crude product obtained in the step (1) to remove magnesium oxide and residual magnesium silicide raw materials, so as to obtain the carbon-coated three-dimensional through porous micron silicon.
Preferably, the particle size of the magnesium silicide in the step (1) is 0.2-10 microns.
Preferably, the magnesium silicide raw material in the step (1) is obtained according to the following method: mixing commercial silicon particles and magnesium powder according to the mass ratio of 1: 1.5-2, reacting for 4-12 hours at 400-700 ℃ under the protection of inert gas, cooling the obtained product, and performing ball milling to obtain the magnesium silicide raw material.
Preferably, the flow rate of the gas in the carbon dioxide-containing atmosphere in the step (1) is 30ml/min to 100ml/min, and the volume concentration of the carbon dioxide in the atmosphere is not lower than 10%.
Preferably, the magnesium silicide raw material in the step (1) is placed in U-shaped sleeves which are oppositely placed so as to increase the residence time of carbon dioxide.
Preferably, the U-shaped sleeves are two, and the open ends of the U-shaped sleeves face inwards, and the closed ends of the U-shaped sleeves face outwards.
According to another aspect of the invention, the carbon-coated porous micron silicon is prepared according to the preparation method.
Preferably, the carbon-coated porous micron silicon is carbon-coated porous micron silicon, the size of the micron silicon is 1-3 microns, the thickness of the carbon layer is 10 nm-30 nm, and the specific surface area of the carbon-coated porous micron silicon is 20-100 m2/g。
Preferably, the carbon-coated porous micron silicon contains 10 wt% -20 wt% of carbon and the balance of silicon.
According to another aspect of the invention, the application of the carbon-coated porous micron silicon is provided for preparing a lithium ion battery negative electrode material.
In general, compared with the prior art, the above technical solution contemplated by the present invention can achieve the following beneficial effects:
(1) the invention provides a preparation method of carbon-coated micron silicon, which is characterized in that magnesium silicide is subjected to oxidation-reduction reaction with carbon dioxide in an atmosphere containing carbon dioxide or is subjected to reaction with carbon dioxide after decomposition, and then the carbon-coated micron silicon material is obtained by acid washing.
(2) In the preparation process of the carbon-coated micron silicon material, the carbon dioxide retention time is prolonged by controlling the conditions of the flow rate, the concentration, the reaction temperature and the like of the carbon dioxide and matching with the improvement of a reaction device, the contact of the carbon dioxide and reaction raw materials is promoted, and the yield of the carbon-coated micron silicon material is greatly increased.
(3) The atmosphere used in the preparation process of the carbon-coated micron silicon is greenhouse gas carbon dioxide, and CO can be realized2High efficiency, high value utilization, low cost and energy conservation and emission reduction.
(4) The silicon-carbon material prepared by the invention is three-dimensional through porous micron, the structure is beneficial to the contact of the electrode material and electrolyte, the outward expansion of the electrode material is relieved, the stability of the lithium ion battery is improved, and in addition, the formed carbon coating structure also greatly improves the conductivity of the electrode material and is more beneficial to the conduction of electrons.
Drawings
FIG. 1 is a schematic diagram of a reaction apparatus in example 1;
FIG. 2 shows the magnesium silicide of example 1 at 700 ℃ and CO2XRD pattern of the reaction product;
FIG. 3 is a scanning electron microscope image of the carbon-coated three-dimensional through porous micron silicon prepared in example 1;
FIG. 4 is a transmission electron microscope image of the carbon-coated three-dimensional through porous micron silicon prepared in example 1;
FIG. 5 is a graph of the cycle performance of the carbon-coated three-dimensional through porous micron silicon prepared in example 1.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
The invention provides a preparation method of carbon-coated micron silicon, which comprises the following steps:
(1) taking magnesium silicide as a raw material, and reacting for 2-24 hours at 400-800 ℃ in an atmosphere containing carbon dioxide to obtain a crude product containing magnesium oxide and carbon-coated silicon; the atmosphere containing carbon dioxide is a carbon dioxide atmosphere or a mixed atmosphere of carbon dioxide and an inert gas. The reaction of magnesium silicide as raw material in the atmosphere containing carbon dioxide may be a redox reaction Mg of magnesium silicide and carbon dioxide2Si+CO2→ Si +2MgO + C; when the temperature is raised to over 750 ℃, decomposition reaction of magnesium silicide may occur to generate magnesiumThe steam and the silicon simple substance, the magnesium steam and the carbon dioxide may further react to generate magnesium oxide and carbon, and because the magnesium steam and the carbon dioxide all generate in-situ reaction, the surface of the silicon generated by the reaction is coated with a carbon layer. The preferable particle size range of the magnesium silicide is 0.2-10 microns.
One of the difficulties in the preparation of carbon-coated silicon micron of the present invention is the need to control the introduction of CO2At a rate of introduction of CO2Too fast a rate may result in excess CO2Reacts with C generated in situ, causes consumption of the C in situ and generates poisonous CO; the flow rate of the gas in the atmosphere containing the carbon dioxide is 30 ml/min-100 ml/min, and the volume concentration of the carbon dioxide in the atmosphere can not be lower than 10%.
The preparation of carbon-coated microsilica according to the invention can be carried out in a tube furnace, but how to let Mg2Si and CO2Fully contacting to make them react more completely to increase the conversion rate and yield of the reaction, the invention improves the reaction device, the magnesium silicide raw material is arranged in U-shaped sleeves which are oppositely arranged to increase the residence time of carbon dioxide and improve the contact opportunity of the magnesium silicide and the carbon dioxide, the U-shaped sleeves can be two or more, and the open end of the U-shaped sleeve faces inwards and the closed end faces outwards.
The selection of the reaction temperature is also very critical, and the reaction is insufficient due to the excessively low temperature; if the temperature is too high, a mixed phase (mainly SiC) is generated, the purity of the product is influenced, and the proper temperature range is 400-800 ℃.
(2) And (2) carrying out acid washing treatment on the crude product obtained in the step (1) to remove magnesium oxide and residual magnesium silicide raw materials, so as to obtain the carbon-coated three-dimensional through porous micron silicon.
The invention improves the whole process flow of the silicon-carbon key preparation method, the parameter conditions of each reaction step and the like, has the outstanding advantages of simple and feasible preparation method compared with the prior art, and only needs to add magnesium silicide in CO2(or CO)2Mixed gas with inert gas) to obtain a large amount of carbon-coated three-dimensional through porous micron silicon, and the yield is up to more than 70%.
According toThe carbon-coated porous micron silicon prepared by the method is carbon-coated porous micron silicon, the size of the micron silicon is 1-3 microns, the thickness of the carbon layer is 10-30 nm, and the specific surface area of the carbon-coated porous micron silicon is 20-100 m2(ii) in terms of/g. The carbon content is 10-20 wt%, and the balance is silicon. Experiments prove that the carbon-coated porous micron silicon prepared by the method is used as the lithium ion battery cathode material, the carbon-coated structure of the carbon-coated porous micron silicon is beneficial to the contact of the electrode material and electrolyte, the outward expansion of the electrode material is relieved, the stability of the lithium ion battery is improved, and the formed carbon-coated structure also greatly improves the conductivity of the electrode material, is more beneficial to the conduction of electrons and can show excellent performance when used as the battery material.
The following are examples:
example 1
(1) Mixing commercial silicon particles and magnesium powder according to a mass ratio of 1: 1.8 mixing evenly and putting into a container;
(2) putting the container filled with the reactants into a high-temperature furnace filled with inert gas, heating to 700 ℃ at the heating rate of 5 ℃/min, keeping the temperature for 6 hours to obtain a product magnesium silicide, and taking out the product after the product is cooled to room temperature along with the furnace;
(3) and (3) putting the product obtained in the step (2) into a ball milling tank under the protection of argon gas for ball milling, and then screening to obtain magnesium silicide micron particles with different sizes, wherein the particle size is 0.2-10 microns.
(4) Placing 2g of the ball-milled magnesium silicide obtained in step (3) in a tube furnace, wherein the specific device is shown in figure 1, figure 1 is a model drawing of the tube furnace device, a sample-containing crucible is sleeved by two U-shaped stainless steels, and a sample and CO are added2The reaction is more complete. Heating to 700 ℃ in carbon dioxide atmosphere, keeping the temperature for 3h, keeping the flow rate of carbon dioxide at 50ml/min, and taking out the product after the product is cooled to room temperature along with the furnace;
(5) and (4) washing the product obtained in the step (4) with hydrochloric acid to remove magnesium oxide and unreacted magnesium silicide, and then cleaning, filtering and drying to obtain the carbon-coated three-dimensional through porous micron silicon.
As can be seen from the XRD diffraction pattern of the reacted sample in FIG. 2, the three strong peaks at 28.4 °, 47.3 ° and 56.1 ° correspond to the three strong peaks of silicon (JCPDS No.27-1402), and the impurity phase is unreacted Mg2Si and MgO are easy to remove.
As can be seen from the scanning electron microscope images in fig. 3 (including fig. 3A and 3B) and the transmission electron microscope images in fig. 4 (including fig. 4A and 4B), the final product prepared in this embodiment is a carbon-coated three-dimensional through porous micro silicon structure. It can be seen that the resulting product is a microparticle with a nano-scale pore structure (formed after etching away MgO with acid) and is a one-step preparation to produce a silicon carbon product. The yield of the carbon-coated micron silicon prepared by the embodiment is 70.1%, the size of the micron silicon is 1-3 microns, the thickness of the carbon layer is 20nm, and the specific surface area is 31.2m2Per g, carbon content 14 wt.%, balance silicon.
FIG. 5 shows the cycle performance of the carbon-coated three-dimensional through porous silicon, the capacity of the carbon-coated three-dimensional through porous micron silicon can reach 1000mA h/g after 400 cycles, the first coulombic efficiency is 79%, and the outstanding cycle stability is shown.
Example 2
(1) Mixing commercial silicon particles and magnesium powder according to a mass ratio of 1:1.5 mixing evenly and putting into a container;
(2) putting the container filled with the reactants into a high-temperature furnace filled with inert gas, heating to 400 ℃ at the heating rate of 5 ℃/min, keeping the temperature for 12 hours to obtain a product magnesium silicide, and taking out the product after the product is cooled to room temperature along with the furnace;
(3) and (3) putting the product obtained in the step (2) into a ball milling tank under the protection of argon gas for ball milling, and then screening to obtain magnesium silicide micron particles with different sizes, wherein the particle size is 1-8 microns.
(4) Placing 2g of the ball-milled magnesium silicide obtained in step (3) in a tube furnace, wherein the specific device is shown in figure 1, figure 1 is a model drawing of the tube furnace device, a sample-containing crucible is sleeved by two U-shaped stainless steels, and a sample and CO are added2The reaction is more complete. Heating to 750 ℃ in carbon dioxide atmosphere, keeping the temperature for 3h, keeping the flow rate of carbon dioxide at 30ml/min, and taking out the product after the product is cooled to room temperature along with the furnace;
(5) and (4) washing the product obtained in the step (4) with hydrochloric acid to remove magnesium oxide, and then cleaning, filtering and drying to obtain the carbon-coated three-dimensional through porous micron silicon.
The obtained product is micron particles with a nanometer level pore structure and is a silicon carbon product prepared in one step. The yield of the carbon-coated micron silicon prepared by the embodiment is 71.6%, the size of the micron silicon is 3-4 microns, the thickness of the carbon layer is 15nm, and the specific surface area is 28.6m2A carbon content of 12 wt%, the balance being silicon.
Example 3
(1) Mixing commercial silicon particles and magnesium powder according to a mass ratio of 1: 2, uniformly mixing and putting into a container;
(2) putting the container filled with the reactants into a high-temperature furnace filled with inert gas, heating to 600 ℃ at the heating rate of 5 ℃/min, keeping the temperature for 4 hours to obtain a product magnesium silicide, and taking out the product after the product is cooled to room temperature along with the furnace;
(3) and (3) putting the product obtained in the step (2) into a ball milling tank under the protection of argon gas for ball milling, and then screening to obtain magnesium silicide micron particles with different sizes, wherein the particle size is 0.5-4 microns.
(4) Placing 2g of the ball-milled magnesium silicide obtained in step (3) in a tube furnace, wherein the specific device is shown in figure 1, figure 1 is a model drawing of the tube furnace device, a sample-containing crucible is sleeved by two U-shaped stainless steels, and a sample and CO are added2The reaction is more complete. Heating to 800 ℃ in carbon dioxide atmosphere, keeping the temperature for 3h, keeping the flow rate of carbon dioxide at 100ml/min, and taking out the product after the product is cooled to room temperature along with the furnace;
(5) and (4) washing the product obtained in the step (4) with hydrochloric acid to remove magnesium oxide, and then cleaning, filtering and drying to obtain the carbon-coated three-dimensional through porous micron silicon.
The final product is micron particles with nanometer level hole structure and is one-step silicon carbon product. The yield of carbon-coated micron silicon prepared by the embodiment is 73.3%, the size of the micron silicon is 1-3 microns, the thickness of a carbon layer is 12nm, and the specific surface area is 24m2(ii)/g, carbon content 10 wt%, balance silicon.
Example 4
(1) Mixing commercial silicon particles and magnesium powder according to a mass ratio of 1: 1.8 mixing evenly and putting into a container;
(2) putting the container filled with the reactants into a high-temperature furnace filled with inert gas, heating to 700 ℃ at the heating rate of 5 ℃/min, keeping the temperature for 6 hours to obtain a product magnesium silicide, and taking out the product after the product is cooled to room temperature along with the furnace;
(3) and (3) putting the product obtained in the step (2) into a ball milling tank under the protection of argon gas for ball milling, and then screening to obtain magnesium silicide micron particles with different sizes, wherein the particle size is 0.2-10 microns.
(4) Placing 2g of the ball-milled magnesium silicide obtained in step (3) in a tube furnace, wherein the specific device is shown in figure 1, figure 1 is a model drawing of the tube furnace device, a sample-containing crucible is sleeved by two U-shaped stainless steels, and a sample and CO are added2The reaction is more complete. Heating to 700 ℃ in the mixed atmosphere of carbon dioxide and argon, preserving the temperature for 3h, wherein the gas flow rate of the carbon dioxide is 20ml/min, the gas flow rate of the argon is 30ml/min, and taking out the product after the product is cooled to room temperature along with the furnace;
(5) and (4) washing the product obtained in the step (4) with hydrochloric acid to remove magnesium oxide and unreacted magnesium silicide, and then cleaning, filtering and drying to obtain the carbon-coated three-dimensional through porous micron silicon.
The final product is micron particles with nanometer level hole structure and is one-step silicon carbon product. The yield of the carbon-coated micron silicon prepared by the embodiment is 74.9%, the size of the micron silicon is 1-3 microns, the thickness of a carbon layer is 10nm, and the specific surface area is 20m2(ii)/g, 8 wt% carbon, balance silicon.
It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (3)

1. A preparation method of carbon-coated micron silicon is characterized by comprising the following steps:
(1) taking magnesium silicide as a raw material, and reacting for 2-24 hours at 400-800 ℃ in an atmosphere containing carbon dioxide to obtain a crude product containing magnesium oxide and carbon-coated silicon; the atmosphere containing carbon dioxide is carbon dioxide atmosphere or mixed atmosphere of carbon dioxide and inert gas; the flow rate of gas in the atmosphere containing carbon dioxide is 30 ml/min-100 ml/min, and the volume concentration of carbon dioxide in the atmosphere is not lower than 10%; the magnesium silicide raw material is placed in U-shaped sleeves which are oppositely placed so as to increase the residence time of carbon dioxide; the number of the U-shaped sleeves is two, the opening ends of the U-shaped sleeves face inwards, and the closed ends of the U-shaped sleeves face outwards;
(2) and (2) carrying out acid washing treatment on the crude product obtained in the step (1) to remove magnesium oxide and residual magnesium silicide raw materials, so as to obtain the carbon-coated three-dimensional through porous micron silicon.
2. The method according to claim 1, wherein the magnesium silicide in the step (1) has a particle size of 0.2 to 10 μm.
3. The method of claim 1, wherein the magnesium silicide feedstock of step (1) is obtained by: mixing commercial silicon particles and magnesium powder according to the mass ratio of 1: 1.5-2, reacting for 4-12 hours at 400-700 ℃ under the protection of inert gas, cooling the obtained product, and performing ball milling to obtain the magnesium silicide raw material.
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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN2358042Y (en) * 1997-11-05 2000-01-12 梁双林 Carbon dioxide generator
CN202582331U (en) * 2012-04-18 2012-12-05 南京斯迈柯特种金属装备股份有限公司 Corrosion-resistant titanium U-shaped pipe heat exchanger pipe plate structure

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6869582B2 (en) * 2003-01-24 2005-03-22 Air Products And Chemicals, Inc. Process for the synthesis of BrSF5
CN104986768A (en) * 2015-05-18 2015-10-21 中国科学技术大学 Method for synthesizing silicon nanopowder through nitridation, and application thereof
CN105826527B (en) * 2016-03-22 2018-07-06 浙江大学 A kind of porous silicon-carbon composite and its preparation method and application

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN2358042Y (en) * 1997-11-05 2000-01-12 梁双林 Carbon dioxide generator
CN202582331U (en) * 2012-04-18 2012-12-05 南京斯迈柯特种金属装备股份有限公司 Corrosion-resistant titanium U-shaped pipe heat exchanger pipe plate structure

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