Preparation method of microsphere silicon-carbon precursor

Abstract

The invention discloses a microsphere silicon carbon precursor preparation method which comprises the following steps: preparing the following component materials in percentage by mass: 30%-40% of an organic compound precursor, 30%-40% of absolute ethyl alcohol, 3%-4% of ammonium persulfate, 12%-15% of silicon powder, 0.7%-1% of a silane coupling agent, 0.2%-0.3% of an antioxidant, 0.1%-0.2% of a purifying agent, 0.1%-0.2% of a dispersing agent, 0.1%-0.3% of a surfactant and 0.3%-0.4% of a nucleating agent; according to the preparation method of the microsphere silicon-carbon precursor, high-purity adsorption resin and epoxy resin are used as components of a basic organic compound precursor, so that the high purity of raw materials is ensured, a firm framework support is provided for a precursor structure, and the mechanical strength and chemical stability of a final product are enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of silicon-carbon materials, and in particular to a method for preparing a microsphere silicon-carbon precursor. Background Art

[0002] Microspherical silicon carbon precursor usually refers to a composite material precursor composed of silicon and carbon elements with a microspherical morphology. Microspherical silicon carbon materials have great application potential in energy storage, catalysis, adsorption and biomedicine due to their unique structure and properties. The preparation of microspherical silicon carbon precursor is a key step in obtaining high-quality microspherical silicon carbon materials.

[0003] Traditional methods for preparing microspherical silicon-carbon precursors often only take simple cleaning and screening measures when processing raw materials, which makes it difficult for the purity of the prepared precursor to meet the standards required for high-performance applications. Impurities in the raw materials and problems with uneven particle size distribution caused by particle agglomeration will have an adverse effect on the purity of the microspherical silicon-carbon precursor. The presence of impurities will not only reduce the purity of the precursor, but may also introduce defects in the internal structure of the precursor, thereby affecting its subsequent processing performance and the performance of the final product. In addition, the agglomeration of particles will lead to an uneven particle size distribution of the precursor, which will not only affect its dispersibility, but may also form large particles during the preparation of the precursor, reducing its specific surface area and reaction activity. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing a microspherical silicon-carbon precursor to solve the problem of uneven particle size distribution caused by impurities and particle agglomeration in the raw materials mentioned in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for preparing a microspherical silicon-carbon precursor, the preparation steps of which are as follows:

[0006] Step 1: Prepare the following component materials by mass fraction: organic compound precursor 30%-40%, anhydrous ethanol 30%-40%, ammonium persulfate 3%-4%, silicon powder 12%-15%, silane coupling agent 0.7%-1%, antioxidant 0.2%-0.3%, purifying agent 0.1%-0.2%, dispersant 0.1%-0.2%, surfactant 0.1%-0.3%, nucleating agent 0.3%-0.4%;

[0007] Step 2: dissolving the organic compound precursor in anhydrous ethanol to form solution A;

[0008] Step 3: Add silicon powder to solution A and stir for 90 minutes to evenly disperse the silicon powder in the solution, then add silane coupling agent, antioxidant, purifying agent, dispersant, surfactant and nucleating agent in sequence, and after each additive is added, stir and mix them thoroughly with a stirrer to obtain solution B;

[0009] Step 4: dissolving ammonium persulfate in water of the same volume as the anhydrous ethanol in step 2, then slowly dropping the prepared ammonium persulfate solution into solution B under ice-water bath conditions, reacting in an ice-water bath for 8 hours, washing with water every 2 hours during the reaction, and finally drying in an oven after 2 hours of ice-water bath reaction, and presenting a dry, dark green solid state, to obtain a dark green product silicon@polyaniline;

[0010] Step 5: Take the above silicon@polyaniline, keep it at a temperature range of 600°C for 12 hours under the protection of helium atmosphere, and then cool it to room temperature to obtain a microspherical silicon carbon precursor;

[0011] The organic compound precursor is a mixture of adsorption resin, epoxy resin, hydrogen-containing polysilicone and vinyl polysilicone, and the mixing ratio of the adsorption resin, epoxy resin, hydrogen-containing polysilicone and vinyl polysilicone is 4:2:1:9.

[0012] As a preferred technical solution of the present invention, the silicon powder is nano-scale silicon dioxide.

[0013] As a preferred technical solution of the present invention, the silane coupling agent is one or more of γ-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane or N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane.

[0014] As a preferred technical solution of the present invention, the antioxidant is one or more of ascorbic acid, vitamin E or butylated hydroxyanisole.

[0015] As a preferred technical solution of the present invention, the purifying agent is an activated carbon adsorbent.

[0016] As a preferred technical solution of the present invention, the dispersant is polyethylene glycol.

[0017] As a preferred technical solution of the present invention, the surfactant is a mixture of sodium stearate and dodecyl polyoxyethylene ether, and the mixing ratio of sodium stearate and dodecyl polyoxyethylene ether is 1:1.

[0018] As a preferred technical solution of the present invention, the nucleating agent is calcium carbonate.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. When selecting raw materials, the present invention adopts high-purity adsorption resin and epoxy resin as components of the basic organic compound precursor, which not only ensures the high purity of the raw materials themselves, but also cleverly utilizes the unique properties of the two resins - the strong adsorption capacity of the adsorption resin helps to capture and remove trace impurities, while the epoxy resin provides a solid skeleton support for the precursor structure with its excellent adhesion and stability, and enhances the mechanical strength and chemical stability of the final product. At the same time, the ion exchange resin can deeply remove ionic impurities in the solution, such as metal ions, chloride ions, etc. These impurities often reduce the conductivity of the microspherical silicon carbon, which is conducive to obtaining high-quality and high-performance microspherical silicon carbon products after treatment.

[0021] 2. In the process of preparing the microspherical silicon-carbon precursor, the present invention adopts an inert gas atmosphere for heat treatment in order to effectively treat the harmful gases generated during the preparation process. Inert gas has the characteristics of stable chemical properties and is not easy to react with other substances. It can protect the microspherical silicon-carbon precursor from the influence of active gases such as oxygen and reduce the generation of harmful gases. In addition, by accurately controlling parameters such as temperature and time during the heat treatment process, the amount of harmful gases generated is further reduced. Specifically, by reducing the emission of harmful gases, the present invention not only reduces the pollution to the environment, but also reduces the additional cost of treating these harmful gases.

[0022] 3. The present invention achieves precise control of particle size distribution and morphology by precisely controlling the raw material ratio, reaction conditions and types of additives. The selection of nano-scale silicon dioxide makes the final product have a smaller particle size and uniform particle size distribution, and improves the dispersibility and stability of the raw materials in the solution. At the same time, the slow addition of ammonium persulfate solution and sufficient stirring under ice-water bath conditions ensures uniform mixing and sufficient reaction of the raw materials, so that the final microspherical silicon-carbon precursor has a regular morphology and good dispersibility. And the microspherical silicon-carbon precursor has a uniform particle size distribution, regular morphology and a smooth surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention is a flow chart for preparing a microspherical silicon-carbon precursor;

[0024] Figure 2 This is a 500nm transmission electron microscope image of the microspherical silicon carbon of the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] See also Figure 1 The present invention provides a technical solution for preparing a microspherical silicon-carbon precursor:

[0027] In some specific embodiments of the present invention, the organic compound precursor is a mixture of adsorption resin, epoxy resin, hydrogen-containing polysilicone and vinyl polysilicone, and the mixing ratio of adsorption resin, epoxy resin, hydrogen-containing polysilicone and vinyl polysilicone is 4:2:1:9. Among them, the adsorption resin can effectively remove impurities in the solution due to its excellent adsorption performance, and improve the purity and quality of the product; the epoxy resin provides a solid skeleton support for the precursor structure with its excellent adhesion and stability, and enhances the mechanical strength and chemical stability of the final product; the unsaturated bonds in hydrogen-containing polysilicone and vinyl polysilicone are easy to undergo cross-linking reaction at high temperature, which helps to form a stable carbonization structure and endow the microsphere silicon carbon precursor with excellent conductivity and thermal stability; at the same time, the mixture generates less waste in the preparation process, and is easy to degrade in nature, and will not cause long-term pollution to the environment.

[0028] Among them, the mixture of hydrogenated polysilicone and vinyl polysilicone selected as the organic compound precursor contains an imine group. At this time, the selected precursor has a functional group or reactive site similar to that of aniline, and the hydrogenated polysilicone containing silicon-hydrogen bonds and vinyl polysilicone containing carbon-carbon unsaturated bonds in the precursor may form a chain structure or functional group distribution similar to that of polyaniline during the polymerization process. Therefore, under the action of ammonium persulfate solution, the organic compound precursor undergoes a polymerization reaction to form a high molecular weight polymer, and then through ice-water bath reaction conditions, a silicon@polyaniline composite material with a specific structure and performance can be obtained, wherein the chemical reaction formula is as follows:

[0029]

[0030] In the above chemical reactions, SiH: represents the simplified form of hydrogen-containing polysilane, where a represents the number of hydrogen atoms contained in each molecule. CH-SiH: represents the simplified form of vinyl polysilane, where b and c represent the number of hydrogen atoms on the vinyl group and the silicon-hydrogen bond, respectively. N (imine source): represents the compound that provides the imine group (a mixture of hydrogen-containing polysilicone and vinyl polysilicone). C6H4NH: represents the simplified form of polyaniline, where 2n+2m represents the relationship between the chain length of the polymer and the molar amount of the reactant. Si02(RH): represents the simplified form of polysiloxane, where (Si02) represents the skeleton structure of the silicon-oxygen bond, (RH) represents the organic group connected to the silicon atom, R represents the organic group, x, y, z, and w are reaction coefficients, which are used to represent the relationship between structure and quantity. It should be noted that the actual structure of polysiloxane may be more complicated than this simplified representation. SO42- represents sulfate ions, which are the products of the decomposition of ammonium persulfate. H+: represents hydrogen ions, which come from the decomposition of ammonium persulfate. H2O: represents water molecules, which are one of the by-products produced in the reaction.

[0031] In some specific embodiments of the present invention, ammonium persulfate is treated with ion exchange resin for impurity removal. The ion exchange resin has a high degree of selectivity and adsorption capacity. The ionic groups on the surface of the resin adsorb ions in the solution through electrostatic action or chemical bonding, so that specific ions in the solution can be efficiently removed. By removing ionic impurities in the solution, the purity of the microspherical silicon carbon precursor can be significantly improved; and the addition of ammonium persulfate helps to promote the dissolution or conversion of certain impurity ions, thereby making them more easily adsorbed by the ion exchange resin. As an inorganic compound, ammonium persulfate has lower environmental risks and biological toxicity than other organic impurity removers.

[0032] In some specific embodiments of the present invention, the ice-water bath condition refers to using a mixture of ice and water as a cooling medium to maintain the temperature of the reaction system at a low temperature close to 0°C; the ice-water bath can ensure that the reaction proceeds at a relatively slow and controllable rate, which is conducive to obtaining a purer and more clearly structured product, silicon@polyaniline.

[0033] In some specific embodiments of the present invention, nano-scale silicon dioxide, due to its small particle size and large specific surface area, can be more effectively combined with carbon materials to form a more solid composite structure, which can better disperse and withstand stress when subjected to external forces, thereby improving the strength and toughness of the product; nano-scale silicon dioxide has excellent conductive properties and can significantly improve the conductivity of the microspherical silicon carbon precursor.

[0034] In some specific embodiments of the present invention, the silane coupling agent used is one or more of γ-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane or N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane. The silane coupling agent has a special molecular structure, one end of which can react with active groups such as hydroxyl groups on the surface of inorganic material silicon powder, and the other end can combine with organic material carbon, thereby forming a strong chemical bond between the inorganic material and the organic material and enhancing the interface bonding force; the silane coupling agent can improve the dispersibility of nano-scale silicon dioxide in the carbon material, reduce agglomeration, and improve the uniformity and stability of the product.

[0035] In some specific embodiments of the present invention, the antioxidant used is one or more of ascorbic acid, vitamin E or butylated hydroxyanisole. Ascorbic acid, vitamin E and butylated hydroxyanisole all have strong antioxidant properties. They can effectively remove free radicals in the reaction system and prevent oxidative degradation of the material during preparation and storage, thereby improving the stability of the microspherical silicon-carbon precursor; by adding antioxidants, the antioxidants can stabilize the internal structure of the material and reduce defects caused by oxidation, thereby improving the strength and toughness of the microspherical silicon-carbon precursor.

[0036] In some specific embodiments of the present invention, the purifying agent used is an activated carbon adsorbent. The activated carbon has a uniform microporous structure, and its pore diameter is uniform. It can adsorb and screen molecules smaller than its pore diameter, and exclude molecules larger than the pore diameter. This characteristic enables the activated carbon to effectively remove impurities and unreacted substances during the preparation of microsphere silicon carbon precursors, thereby improving the purity and quality of the product; in addition, the regeneration and reuse of the activated carbon reduces the generation of waste and reduces pollution to the environment.

[0037] In some specific embodiments of the present invention, the dispersant is polyethylene glycol, which can reduce the attraction and surface tension between particles, achieve better dispersion effect, and is applicable to various types of particles. The molecular chain of polyethylene glycol is relatively long, which can provide better steric hindrance effect, prevent particles from reaggregating, and provide long-term dispersion effect.

[0038] In some specific embodiments of the present invention, sodium stearate and dodecyl polyoxyethylene ether both have good dispersibility, and can evenly disperse microsphere silicon carbon precursor particles in the solvent, prevent particle agglomeration, and improve the stability of the dispersion system; the mixture of sodium stearate and dodecyl polyoxyethylene ether is suitable for the preparation of various types of microsphere silicon carbon precursors, including microspheres of different particle sizes, shapes and compositions, which makes the mixture more flexible and applicable in the preparation process; compared with other surfactants of the same category, the mixture of sodium stearate and dodecyl polyoxyethylene ether has better biodegradability. This helps to reduce the impact on the environment.

[0039] In some specific embodiments of the present invention, calcium carbonate can be used as a nucleus formation medium during the crystallization process, promote the formation and growth of crystals, enhance the structural stability of the microsphere silicon carbon precursor, and prevent agglomeration or deformation during the preparation and subsequent treatment. In the preparation of the microsphere silicon carbon precursor, the addition of calcium carbonate helps to form a uniform and fine crystal structure, thereby improving the overall performance of the material. Calcium carbonate has good biocompatibility. Compared with other nucleating agents of the same type, calcium carbonate does not cause adverse reactions or toxicity in the body, which helps to reduce the generation of waste and environmental pollution; calcium carbonate has high thermal stability and can maintain the stability of its structure and performance in a high temperature environment.

[0040] In some specific embodiments of the present invention, Figure 2 As shown, Figure a is a transmission electron microscope photo of nano-silica and core-shell polyaniline / silica microspheres in this scheme, from which it can be seen that the nano-silica without polyaniline is spherical with a diameter of about 500nm, and the particle size distribution is relatively uniform after impurity removal and dispersion. Figure b is a polyaniline belt with a loose structure formed by bulk polymerization of excess aniline in a hydrochloric acid solution, which is attached between the polyaniline / silica microspheres, with a diameter of about 500nm, and the agglomeration of the particles leads to an uneven particle size distribution.

[0041] Embodiment 1:

[0042] A method for preparing a microspherical silicon-carbon precursor, the preparation steps are as follows:

[0043] Step 1: Prepare the following component materials by mass fraction: 30% organic compound precursor, 30% anhydrous ethanol, 3% ammonium persulfate, 12% silicon powder, 0.7% silane coupling agent, 0.2% antioxidant, 0.1% purifying agent, 0.1% dispersant, 0.1% surfactant, and 0.3% nucleating agent;

[0044] Step 2: dissolving the organic compound precursor in anhydrous ethanol to form solution A;

[0045] Step 3: Add silicon powder to solution A and stir for 90 minutes to evenly disperse the silicon powder in the solution, then add silane coupling agent, antioxidant, purifying agent, dispersant, surfactant and nucleating agent in sequence, and after each additive is added, stir and mix them thoroughly with a stirrer to obtain solution B;

[0046] Step 4: dissolving ammonium persulfate in water of the same volume as the anhydrous ethanol in step 2, then slowly dropping the prepared ammonium persulfate solution into solution B under ice-water bath conditions, reacting in an ice-water bath for 8 hours, washing with water every 2 hours during the reaction, and finally drying in an oven after 2 hours of ice-water bath reaction, and presenting a dry, dark green solid state, to obtain a dark green product silicon@polyaniline;

[0047] Step 5: Take the above precursor, keep it in a temperature range of 600° C. for 12 hours under the protection of a helium atmosphere, and then cool it to room temperature to obtain a microspherical silicon-carbon precursor.

[0048] Embodiment 2:

[0049] Based on Example 1, a method for preparing a microspherical silicon-carbon precursor is provided, and the preparation steps are as follows:

[0050] Step 1: Prepare the following component materials by mass fraction: organic compound precursor 40%, anhydrous ethanol 40%, ammonium persulfate 3%, silicon powder 12%, silane coupling agent 0.7%, antioxidant 0.2%, purifying agent 0.1%, dispersant 0.1%, surfactant 0.1%, nucleating agent 0.3%;

[0051] Step 2: dissolving the organic compound precursor in anhydrous ethanol to form solution A;

[0052] Step 3: Add silicon powder to solution A and stir for 90 minutes to evenly disperse the silicon powder in the solution, then add silane coupling agent, antioxidant, purifying agent, dispersant, surfactant and nucleating agent in sequence, and after each additive is added, stir and mix them thoroughly with a stirrer to obtain solution B;

[0053] Step 4: dissolving ammonium persulfate in water of the same volume as the anhydrous ethanol in step 2, then slowly dropping the prepared ammonium persulfate solution into solution B under ice-water bath conditions, reacting in an ice-water bath for 8 hours, washing with water every 2 hours during the reaction, and finally drying in an oven after 2 hours of ice-water bath reaction, and presenting a dry, dark green solid state, to obtain a dark green product silicon@polyaniline;

[0054] Step 5: Take the above precursor, keep it in a temperature range of 600° C. for 12 hours under the protection of a helium atmosphere, and then cool it to room temperature to obtain a microspherical silicon-carbon precursor.

[0055] Embodiment three:

[0056] On the basis of Example 2, on the basis of Example 1, a method for preparing a microspherical silicon-carbon precursor is provided, and the preparation steps are as follows:

[0057] Step 1: Prepare the following component materials by mass fraction: organic compound precursor 40%, anhydrous ethanol 40%, ammonium persulfate 4%, silicon powder 12%, silane coupling agent 0.7%, antioxidant 0.2%, purifying agent 0.1%, dispersant 0.1%, surfactant 0.1%, nucleating agent 0.3%;

[0058] Step 2: dissolving the organic compound precursor in anhydrous ethanol to form solution A;

[0059] Step 3: Add silicon powder to solution A and stir for 90 minutes to evenly disperse the silicon powder in the solution, then add silane coupling agent, antioxidant, purifying agent, dispersant, surfactant and nucleating agent in sequence, and after each additive is added, stir and mix them thoroughly with a stirrer to obtain solution B;

[0060] Step 4: dissolving ammonium persulfate in water of the same volume as the anhydrous ethanol in step 2, then slowly dropping the prepared ammonium persulfate solution into solution B under ice-water bath conditions, reacting in an ice-water bath for 8 hours, washing with water every 2 hours during the reaction, and finally drying in an oven after 2 hours of ice-water bath reaction, and presenting a dry, dark green solid state, to obtain a dark green product silicon@polyaniline;

[0061] Step 5: Take the above precursor, keep it in a temperature range of 600° C. for 12 hours under the protection of a helium atmosphere, and then cool it to room temperature to obtain a microspherical silicon-carbon precursor.

[0062] Embodiment 4:

[0063] On the basis of Example 3 and Example 1, a method for preparing a microspherical silicon-carbon precursor is provided, and the preparation steps are as follows:

[0064] Step 1: Prepare the following component materials by mass fraction: 40% organic compound precursor, 40% anhydrous ethanol, 4% ammonium persulfate, 15% silicon powder, 0.7% silane coupling agent, 0.2% antioxidant, 0.1% purifying agent, 0.1% dispersant, 0.1% surfactant, and 0.3% nucleating agent;

[0065] Step 2: dissolving the organic compound precursor in anhydrous ethanol to form solution A;

[0066] Step 3: Add silicon powder to solution A and stir for 90 minutes to evenly disperse the silicon powder in the solution, then add silane coupling agent, antioxidant, purifying agent, dispersant, surfactant and nucleating agent in sequence, and after each additive is added, stir and mix them thoroughly with a stirrer to obtain solution B;

[0067] Step 4: dissolving ammonium persulfate in water of the same volume as the anhydrous ethanol in step 2, then slowly dropping the prepared ammonium persulfate solution into solution B under ice-water bath conditions, reacting in an ice-water bath for 8 hours, washing with water every 2 hours during the reaction, and finally drying in an oven after 2 hours of ice-water bath reaction, and presenting a dry, dark green solid state, to obtain a dark green product silicon@polyaniline;

[0068] Step 5: Take the above precursor, keep it in a temperature range of 600° C. for 12 hours under the protection of a helium atmosphere, and then cool it to room temperature to obtain a microspherical silicon-carbon precursor.

[0069] Embodiment five:

[0070] On the basis of Example 3 and Example 1, a method for preparing a microspherical silicon-carbon precursor is provided, and the preparation steps are as follows:

[0071] Step 1: Prepare the following component materials by mass fraction: organic compound precursor 40%, anhydrous ethanol 40%, ammonium persulfate 4%, silicon powder 12%, silane coupling agent 1%, antioxidant 0.2%, purifying agent 0.1%, dispersant 0.1%, surfactant 0.1%, nucleating agent 0.3%;

[0072] Step 2: dissolving the organic compound precursor in anhydrous ethanol to form solution A;

[0073] Step 3: Add silicon powder to solution A and stir for 90 minutes to evenly disperse the silicon powder in the solution, then add silane coupling agent, antioxidant, purifying agent, dispersant, surfactant and nucleating agent in sequence, and after each additive is added, stir and mix them thoroughly with a stirrer to obtain solution B;

[0074] Step 4: dissolving ammonium persulfate in water of the same volume as the anhydrous ethanol in step 2, then slowly dropping the prepared ammonium persulfate solution into solution B under ice-water bath conditions, reacting in an ice-water bath for 8 hours, washing with water every 2 hours during the reaction, and finally drying in an oven after 2 hours of ice-water bath reaction, and presenting a dry, dark green solid state, to obtain a dark green product silicon@polyaniline;

[0075] Step 5: Take the above precursor, keep it in a temperature range of 600° C. for 12 hours under the protection of a helium atmosphere, and then cool it to room temperature to obtain a microspherical silicon-carbon precursor.

[0076] Embodiment six:

[0077] On the basis of Example 5 and Example 1, a method for preparing a microspherical silicon-carbon precursor is provided, and the preparation steps are as follows:

[0078] Step 1: Prepare the following component materials by mass fraction: organic compound precursor 40%, anhydrous ethanol 40%, ammonium persulfate 4%, silicon powder 12%, silane coupling agent 1%, antioxidant 0.3%, purifying agent 0.1%, dispersant 0.1%, surfactant 0.1%, nucleating agent 0.3%;

[0079] Step 2: dissolving the organic compound precursor in anhydrous ethanol to form solution A;

[0080] Step 3: Add silicon powder to solution A and stir for 90 minutes to evenly disperse the silicon powder in the solution, then add silane coupling agent, antioxidant, purifying agent, dispersant, surfactant and nucleating agent in sequence, and after each additive is added, stir and mix them thoroughly with a stirrer to obtain solution B;

[0081] Step 4: dissolving ammonium persulfate in water of the same volume as the anhydrous ethanol in step 2, then slowly dropping the prepared ammonium persulfate solution into solution B under ice-water bath conditions, reacting in an ice-water bath for 8 hours, washing with water every 2 hours during the reaction, and finally drying in an oven after 2 hours of ice-water bath reaction, and presenting a dry, dark green solid state, to obtain a dark green product silicon@polyaniline;

[0082] Step 5: Take the above precursor, keep it in a temperature range of 600° C. for 12 hours under the protection of a helium atmosphere, and then cool it to room temperature to obtain a microspherical silicon-carbon precursor.

[0083] Embodiment seven:

[0084] On the basis of Example 5 and Example 1, a method for preparing a microspherical silicon-carbon precursor is provided, and the preparation steps are as follows:

[0085] Step 1: Prepare the following component materials by mass fraction: organic compound precursor 40%, anhydrous ethanol 40%, ammonium persulfate 4%, silicon powder 12%, silane coupling agent 1%, antioxidant 0.2%, purifying agent 0.2%, dispersant 0.1%, surfactant 0.1%, nucleating agent 0.3%;

[0086] Step 2: dissolving the organic compound precursor in anhydrous ethanol to form solution A;

[0087] Step 3: Add silicon powder to solution A and stir for 90 minutes to evenly disperse the silicon powder in the solution, then add silane coupling agent, antioxidant, purifying agent, dispersant, surfactant and nucleating agent in sequence, and after each additive is added, stir and mix them thoroughly with a stirrer to obtain solution B;

[0088] Step 4: dissolving ammonium persulfate in water of the same volume as the anhydrous ethanol in step 2, then slowly dropping the prepared ammonium persulfate solution into solution B under ice-water bath conditions, reacting in an ice-water bath for 8 hours, washing with water every 2 hours during the reaction, and finally drying in an oven after 2 hours of ice-water bath reaction, and presenting a dry, dark green solid state, to obtain a dark green product silicon@polyaniline;

[0089] Step 5: Take the above precursor, keep it in a temperature range of 600° C. for 12 hours under the protection of a helium atmosphere, and then cool it to room temperature to obtain a microspherical silicon-carbon precursor.

[0090] Embodiment eight:

[0091] On the basis of Example 5 and Example 1, a method for preparing a microspherical silicon-carbon precursor is provided, and the preparation steps are as follows:

[0092] Step 1: Prepare the following component materials by mass fraction: organic compound precursor 40%, anhydrous ethanol 40%, ammonium persulfate 4%, silicon powder 12%, silane coupling agent 1%, antioxidant 0.2%, purifying agent 0.1%, dispersant 0.2%, surfactant 0.1%, nucleating agent 0.3%;

[0093] Step 2: dissolving the organic compound precursor in anhydrous ethanol to form solution A;

[0094] Step 3: Add silicon powder to solution A and stir for 90 minutes to evenly disperse the silicon powder in the solution, then add silane coupling agent, antioxidant, purifying agent, dispersant, surfactant and nucleating agent in sequence, and after each additive is added, stir and mix them thoroughly with a stirrer to obtain solution B;

[0095] Step 4: dissolving ammonium persulfate in water of the same volume as the anhydrous ethanol in step 2, then slowly dropping the prepared ammonium persulfate solution into solution B under ice-water bath conditions, reacting in an ice-water bath for 8 hours, washing with water every 2 hours during the reaction, and finally drying in an oven after 2 hours of ice-water bath reaction, and presenting a dry, dark green solid state, to obtain a dark green product silicon@polyaniline;

[0096] Step 5: Take the above precursor, keep it in a temperature range of 600° C. for 12 hours under the protection of a helium atmosphere, and then cool it to room temperature to obtain a microspherical silicon-carbon precursor.

[0097] Embodiment nine:

[0098] On the basis of Example 8 and Example 1, a method for preparing a microspherical silicon-carbon precursor is provided, and the preparation steps are as follows:

[0099] Step 1: Prepare the following component materials by mass fraction: organic compound precursor 40%, anhydrous ethanol 40%, ammonium persulfate 4%, silicon powder 12%, silane coupling agent 1%, antioxidant 0.2%, purifying agent 0.1%, dispersant 0.2%, surfactant 0.2%, nucleating agent 0.3%;

[0100] Step 2: dissolving the organic compound precursor in anhydrous ethanol to form solution A;

[0101] Step 3: Add silicon powder to solution A and stir for 90 minutes to evenly disperse the silicon powder in the solution, then add silane coupling agent, antioxidant, purifying agent, dispersant, surfactant and nucleating agent in sequence, and after each additive is added, stir and mix them thoroughly with a stirrer to obtain solution B;

[0102] Step 4: dissolving ammonium persulfate in water of the same volume as the anhydrous ethanol in step 2, then slowly dropping the prepared ammonium persulfate solution into solution B under ice-water bath conditions, reacting in an ice-water bath for 8 hours, washing with water every 2 hours during the reaction, and finally drying in an oven after 2 hours of ice-water bath reaction, and presenting a dry, dark green solid state, to obtain a dark green product silicon@polyaniline;

[0103] Step 5: Take the above precursor, keep it in a temperature range of 600° C. for 12 hours under the protection of a helium atmosphere, and then cool it to room temperature to obtain a microspherical silicon-carbon precursor.

[0104] Embodiment ten:

[0105] On the basis of Example 9 and Example 1, a method for preparing a microspherical silicon-carbon precursor is provided, and the preparation steps are as follows:

[0106] Step 1: Prepare the following component materials by mass fraction: organic compound precursor 40%, anhydrous ethanol 40%, ammonium persulfate 4%, silicon powder 12%, silane coupling agent 1%, antioxidant 0.2%, purifying agent 0.1%, dispersant 0.2%, surfactant 0.2%, nucleating agent 0.4%;

[0107] Step 2: dissolving the organic compound precursor in anhydrous ethanol to form solution A;

[0108] Step 3: Add silicon powder to solution A and stir for 90 minutes to evenly disperse the silicon powder in the solution, then add silane coupling agent, antioxidant, purifying agent, dispersant, surfactant and nucleating agent in sequence, and after each additive is added, stir and mix them thoroughly with a stirrer to obtain solution B;

[0109] Step 4: dissolving ammonium persulfate in water of the same volume as the anhydrous ethanol in step 2, then slowly dropping the prepared ammonium persulfate solution into solution B under ice-water bath conditions, reacting in an ice-water bath for 8 hours, washing with water every 2 hours during the reaction, and finally drying in an oven after 2 hours of ice-water bath reaction, and presenting a dry, dark green solid state, to obtain a dark green product silicon@polyaniline;

[0110] Step 5: Take the above precursor, keep it in a temperature range of 600° C. for 12 hours under the protection of a helium atmosphere, and then cool it to room temperature to obtain a microspherical silicon-carbon precursor.

[0111] Comparative Example 1:

[0112] On the basis of Example 9, in the organic compound precursor, no adsorption resin and epoxy resin material are added, and only hydrogenated polysilicone and vinyl polysilicone are used, and the rest is the same as Example 9.

[0113] Comparative Example 2:

[0114] On the basis of Example 9, the ammonium persulfate was not subjected to resin impurity removal treatment, and the rest was the same as Example 9.

[0115] Comparative Example 3:

[0116] On the basis of Example 9, no silane coupling agent was added, and the rest was the same as Example 9.

[0117] Comparative Example 4:

[0118] On the basis of Example 9, no antioxidant was added, and the rest was the same as Example 9.

[0119] Comparative Example 5:

[0120] On the basis of Example 9, the added surfactant is alkyl sulfonate, and the mixture of sodium stearate and dodecyl polyoxyethylene ether is not used. The rest is the same as Example 9.

[0121] The present invention provides a method for preparing a microspherical silicon-carbon precursor. The microspherical silicon-carbon precursors obtained in Examples 1-10 and Comparative Examples 1-5 are tested for performance. The test results are shown in the following table:

[0122]

[0123] According to the above data, the addition of adsorption resin to the organic compound precursor can significantly remove impurities from the main materials of the microsphere silicon carbon precursor, and select and use it through the purification agent to improve the raw material purity of the microsphere silicon carbon precursor. The epoxy resin provides a solid skeleton support for the precursor structure with its excellent adhesion and stability, and enhances the mechanical strength and chemical stability of the final product, so as to obtain high-quality and high-performance microsphere silicon carbon products. The use of an inert gas atmosphere for heat treatment can protect the microsphere silicon carbon precursor from the influence of active gases such as oxygen, reduce the generation of harmful gases, and reduce the pollution to the environment. By using nano-scale silica and cooperating with a silane coupling agent, the final product has a smaller particle size and a uniform particle size distribution, and improves the dispersibility and stability of the raw materials in the solution. At the same time, nano-scale silica has excellent conductive properties and can significantly improve the conductivity of the microsphere silicon carbon precursor. The use of a mixture of sodium stearate and dodecyl polyoxyethylene ether as a surfactant not only improves the efficiency and quality of the preparation process, but also significantly reduces the potential impact on the environment due to its excellent biodegradability. Biodegradability refers to the ability of a material to gradually decompose into harmless substances through the action of microorganisms in the natural environment. Sodium stearate and dodecyl polyoxyethylene ether are easily decomposed by microorganisms under natural conditions and eventually converted into naturally occurring substances such as carbon dioxide and water, thus avoiding the environmental pollution problems that may be caused by traditional surfactants.

[0124] Raw material purity: indicates the purity percentage of the raw materials used. The higher the purity, the less impurities there are in the raw materials.

[0125] Pollution: It is assessed based on the amount and nature of pollutants generated in the raw materials and preparation processes and is divided into five levels: low, lower, medium, higher, and very high.

[0126] Harmfulness of gases produced: Assess the degree of harm of gases produced during the preparation process to the environment and human body, which is divided into five levels: low, lower, medium, higher, and high.

[0127] Particle size distribution: Indicates the particle size distribution of the final product, in microns (μm).

[0128] Stability: Assess the stability of the product during storage and use, divided into three levels: high, medium and low.

[0129] Degradation effect: Indicates the degradation effect of the product during use, expressed as a percentage.

[0130] Conductivity: Indicates the conductivity of the product, with the unit being Siemens per meter (S / m).

[0131] Strength: Indicates the mechanical strength of the product, measured in megapascals (MPa).

[0132] The above are only specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent replacements or modifications made based on the present invention to solve basically the same technical problems and achieve basically the same technical effects are all included in the protection scope of the present invention.

Claims

1. A method for preparing a microspherical silicon-carbon precursor, the preparation steps are as follows: Step 1: Prepare the following component materials by mass fraction: organic compound precursor 30%-40%, anhydrous ethanol 30%-40%, ammonium persulfate 3%-4%, silicon powder 12%-15%, silane coupling agent 0.7%-1%, antioxidant 0.2%-0.3%, purifying agent 0.1%-0.2%, dispersant 0.1%-0.2%, surfactant 0.1%-0.3%, nucleating agent 0.3%-0.4%; Step 2: dissolving the organic compound precursor in anhydrous ethanol to form solution A; Step 3: Add silicon powder to solution A and stir for 90 minutes to evenly disperse the silicon powder in the solution, then add silane coupling agent, antioxidant, purifying agent, dispersant, surfactant and nucleating agent in sequence, and after each additive is added, stir and mix them thoroughly with a stirrer to obtain solution B; Step 4: dissolving ammonium persulfate in water of the same volume as the anhydrous ethanol in step 2, then slowly dropping the prepared ammonium persulfate solution into solution B under ice-water bath conditions, reacting in an ice-water bath for 8 hours, washing with water every 2 hours during the reaction, and finally drying in an oven after 2 hours of ice-water bath reaction, and presenting a dry, dark green solid state, to obtain a dark green product silicon@polyaniline; Step 5: Take the above silicon@polyaniline, keep it at a temperature range of 600°C for 12 hours under the protection of helium atmosphere, and then cool it to room temperature to obtain a microspherical silicon carbon precursor; in, The organic compound precursor is a mixture of adsorption resin, epoxy resin, hydrogen-containing polysilicone and vinyl polysilicone, and the mixing ratio of the adsorption resin, epoxy resin, hydrogen-containing polysilicone and vinyl polysilicone is 4:2:1:

9.

2. The method for preparing a microspherical silicon-carbon precursor according to claim 1, characterized in that: The silicon powder is nano-scale silicon dioxide.

3. The method for preparing a microspherical silicon-carbon precursor according to claim 1, characterized in that: The silane coupling agent is one or more of γ-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane or N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane.

4. The method for preparing a microspherical silicon-carbon precursor according to claim 1, characterized in that: The antioxidant is one or more of ascorbic acid, vitamin E or butylated hydroxyanisole.

5. The method for preparing a microspherical silicon-carbon precursor according to claim 1, characterized in that: The purifying agent is an activated carbon adsorbent.

6. The method for preparing a microspherical silicon-carbon precursor according to claim 1, characterized in that: The dispersant is polyethylene glycol.

7. The method for preparing a microspherical silicon-carbon precursor according to claim 1, characterized in that: The surfactant is a mixture of sodium stearate and lauryl polyoxyethylene ether, and the mixing ratio of sodium stearate and lauryl polyoxyethylene ether is 1:

1.

8. The method for preparing a microspherical silicon-carbon precursor according to claim 1, characterized in that: The nucleating agent is calcium carbonate.

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