CN107611416B - Silicon-carbon composite material, preparation method and application thereof - Google Patents
Silicon-carbon composite material, preparation method and application thereof Download PDFInfo
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Abstract
The invention discloses a silicon-carbon composite material, a preparation method and application thereof, wherein the method comprises the following steps: and carrying out wet ball milling on the glass powder and the lamellar carbon material to obtain a uniform mixed product of the glass and the carbon material, uniformly mixing the uniform mixed product with magnesium powder and molten salt, compacting the mixture into ingots, carrying out magnesium thermal reaction, and carrying out acid washing treatment on the reaction product to obtain the sandwich-shaped porous silicon/graphene-like structure composite material. The method has simple and easy steps and wide raw material sources, and most importantly, the mixture is made into ingots through a compaction process and then subjected to magnesium thermal reaction, so that the tap density of the silicon-carbon negative electrode material is greatly increased, the volume specific capacity of the negative electrode material is improved, meanwhile, a similar sandwich structure formed by compounding the silicon-carbon negative electrode material with carbon materials such as graphite also effectively improves the electronic conductivity of the material, and improves the compatibility of the silicon-based material and electrolyte, thereby improving the cycle performance and the rate capability of the material, and the method can be applied to the lithium ion battery negative electrode material with high power density and high energy density.
Description
Technical Field
The invention belongs to the field of lithium ion battery cathode materials, and particularly relates to a silicon-carbon composite material, and a preparation method and application thereof.
Background
Lithium ion batteries have become an important energy storage device for portable electronic devices due to their high energy density, however, new batteries used in emerging electric transportation systems should have higher specific capacity, energy density and better cycle life than conventional batteries. Among the numerous lithium ion battery negative electrode materials, silicon is considered to be the most promising material due to its exceptionally high specific capacity, abundant reserves in the earth's crust, and the advantages of the developed manufacturing industrial infrastructure. The research history of silicon for lithium ion batteries has been over 30 years, but the mechanical pulverization and rapid capacity decay of the silicon material seriously affect the cycle performance thereof, thereby limiting the practical application of the silicon material in lithium ion batteries. Carbon materials have extremely stable cycle characteristics although their specific capacities are not high, and thus are the main negative electrode materials on the market at present. The carbon material has higher electronic conductivity and provides a better electronic channel for the composite material; meanwhile, the stress change caused by the volume deformation of the silicon material can be alleviated after the carbon and the silicon material are compounded. The combination of the two materials has attracted more and more attention to the preparation of silicon/carbon composite negative electrode materials with high specific capacity and long service life for lithium ion batteries.
At present, the silicon-carbon composite material mainly comprises a coating type and an embedding type. The coated silicon-carbon composite material is formed by coating a layer of carbon on the surface of silicon, so that the coated silicon-carbon composite material has the functions of buffering phase change caused by the volume effect of the silicon and providing an electron transmission channel. According to different composite structures of silicon and carbon, the coated silicon-carbon composite material can be divided into a core-shell type, a fiber type and a porous type; the active silicon particles are embedded into the structural conductive carbon matrix to obtain the embedded silicon-carbon composite material. However, the existing methods for preparing the silicon-carbon composite material have the disadvantages of harsh conditions, high cost, complex steps, serious pollution, involvement of a plurality of toxic substances and great harm to people. For example, in "preparation method of silicon carbon anode material" (CN104103821A), a catalyst is first placed in a chemical vapor deposition reaction chamber; heating the chemical vapor deposition reaction chamber, introducing a reaction gas source and a carrier gas into the chemical vapor deposition reaction chamber, and making Si-SiOx generated in the chemical vapor deposition reaction process pass through a dynamically rotating carbon matrix subjected to carboxylation treatment to prepare a precursor of the silicon-carbon negative electrode material. The reactant gas source is SiH4、SiH3R、SiH2R2、SiHR3One or more of them, chemical vapor deposition is carried out. The process has high risk coefficient, large operation difficulty coefficient and high cost, and is not suitable for large-scale production. For another example, in "a method for preparing a silicon-carbon negative electrode composite" (CN201710064083.4), a hydrothermal method is used to coat a carbon precursor on the surface of silicon powder, and then the carbon precursor is calcined in an inert atmosphere; dispersing the calcined material in the mixed solution, and drying after high-speed dispersion; and corroding the dried material with a corrosive liquid. The hydrothermal method is adopted to coat carbon on the surface of the silicon, which is not only unsafe, but also low in yield, and the porous silicon obtained by corrosion of the corrosive liquid has a pore channel structureMessy and can be pulverized during circulation. In addition, the carbon coating of nano-silicon is performed by Laser treatment, for example, the document "One-Step Synthesis of Si @ C Nanoparticles by Laser Pyrolysis": High performance inorganic materials for Lithium-Ion Batteries (ACS appl. Material. interfaces 2015,7(12): 6637-) 6644), which requires a Laser treatment apparatus, requires High usage of acetylene gas, has High requirements on equipment, is expensive, and cannot be widely applied in large scale.
In addition, the composite material prepared by the method has the defects of low volume energy density and power energy density and incapability of meeting the application requirements of the battery cathode material.
Disclosure of Invention
Aiming at the defects or improvement requirements of the prior art, the invention provides a silicon-carbon composite material, a preparation method and application thereof, and aims to obtain the silicon-carbon composite material by uniformly mixing waste silicate-based glass powder and a lamellar carbon material, then mixing the mixture with magnesium powder and molten salt, and performing magnesium thermal reaction on the mixture in a hydraulic manner to obtain a silicon-carbon composite material.
In order to achieve the above object, according to one aspect of the present invention, there is provided a silicon-carbon composite comprising three-dimensionally through porous silicon and laminar graphite, wherein the porous silicon is located between the laminar graphite to form a sandwich structure, and the porous silicon has a three-dimensionally through-hole structure; the composite material comprises 20-80% of silicon by mass and the balance of carbon.
Preferably, the size of porous silicon particles in the composite material is 1-5 microns, the thickness of the lamellar graphite is 10-20 nanometers, and the size of the lamellar graphite is 5-10 microns; the size of the macroporous structure of the composite material is 50-200 nanometers, and the size of the mesoporous structure is 2-6 nanometers.
Preferably, the tap density of the composite material is 0.87-0.96 g/cm3The compaction density is 1.36-1.54 g/cm3The specific surface area is 120-150 m2g-1。
According to another aspect of the present invention, there is provided a method for preparing a silicon-carbon composite material, comprising the steps of:
(1) mixing silicate glass powder and lamellar carbon materials, performing wet ball milling, performing solid-liquid separation, and drying to obtain a uniformly mixed mixture of the silicate glass powder and the lamellar carbon materials;
(2) mixing the silicate glass powder obtained in the step (1) with a mixture of a lamellar carbon material, magnesium powder and molten salt, compacting into ingots, and then carrying out a magnesiothermic reduction reaction in an inert atmosphere; and carrying out acid washing treatment on the reaction product to obtain the silicon-carbon composite material.
Preferably, the particle size of the silicate glass powder in the step (1) is 5-10 microns.
Preferably, the laminar carbon material is a carbon material having a laminar structure comprising one or more of natural graphite, artificial graphite or expanded graphite.
Preferably, the laminar carbon material is expanded graphite.
Preferably, the mass ratio of the silicate glass powder to the lamellar carbon material in the step (1) is 10: 0.5-2.
Preferably, the wet ball milling time in the step (1) is 6-12 hours, and the solvent is alcohol.
Preferably, the mixture of the silicate glass powder and the lamellar carbon material in the step (2) is firstly carbonized and then mixed with the magnesium powder and the molten salt; the carbonization treatment preferably comprises the following specific steps: heating the mixture to 800-1200 ℃ at a heating rate of 1-10 ℃/min in an argon environment, preserving heat for 1-3 h, annealing and crushing.
Preferably, the mass ratio of the mixture of silicate glass powder and lamellar carbon material, magnesium powder and molten salt in the step (2) is 1: 0.3-0.4: 3 to 5.
Preferably, the molten salt of step (2) comprises one or more of magnesium chloride, sodium chloride and potassium chloride.
Preferably, the molten salt is an equal mass ratio mixture of sodium chloride and potassium chloride.
Preferably, the pressure range adopted by the compaction into ingots in the step (2) is 10-50 MPa.
Preferably, said compacting into ingots is achieved by using a hydraulic press, a press or a cold press.
Preferably, the magnesiothermic reduction reaction conditions of step (2) are: heating to 600-800 ℃ at a heating rate of 2-10 ℃/min in an argon atmosphere, and preserving heat for 3-6 h.
According to another aspect of the invention, the application of the silicon-carbon composite material is provided, and the silicon-carbon composite material is used as a lithium ion battery negative electrode material.
In general, the above technical solutions contemplated by the present invention can achieve the following advantageous effects compared to the prior art.
(1) The silicon-carbon composite material provided by the invention is a silicon-carbon composite structure which is formed by compounding porous silicon and graphene-like laminar graphite and has a similar sandwich structure, has very high tap density and compaction density, high specific mass capacity and specific volume capacity, limited electrode expansion and excellent cycling stability, and is an ideal material for a lithium ion battery cathode.
(2) The invention adopts a compaction ingot forming technology, after silicate-based glass and carbon materials such as graphite are uniformly mixed, the mixture is compacted into an ingot with magnesium powder and fused salt, then magnesium thermal reaction is carried out, and acid washing is carried out to obtain the silicon-carbon composite material. The method comprises the steps of mixing and compacting reactants and molten salt together under the action of mechanical force, wherein the reactants and the molten salt are compacted, the graphite is in closer contact with silicate glass by compacting the ingots, then the magnesium thermal reaction is carried out at 700 ℃ by utilizing the melting point of the silicate glass, the graphite reacts in a flowing melting state, the reaction is more sufficient, the graphite permeates into graphite layers more easily to react, and the sandwich-shaped porous silicon/graphene-like structure composite material obtained after cooling has higher tap density.
(3) The waste silicate glass and the common carbon material are used as raw materials to prepare the silicon-carbon composite material, and the waste silicate glass and the carbon material have low cost and rich content, so that the silicon-carbon composite material is a cheap and high-quality silicon-carbon cathode production raw material for the lithium ion battery.
(4) In the preparation process, halides such as magnesium chloride, potassium chloride, sodium chloride and the like are used as molten salts, and the melting points of the molten salts are also between 600 ℃ and 750 ℃, so that on one hand, the stable reaction environment is ensured, the molten salts are used as heat absorbing agents to avoid the over-fast growth and grain refinement of grains, the agglomeration and sintering of products can be prevented, the generation of byproducts can be prevented, the product purity can be improved, the whole reaction is easier to carry out, the reaction is more sufficient, and the whole reaction is safer.
(5) The silicate glass is in a molten state at 600-750 ℃, the temperature is also in a reaction temperature range, the magnesium powder is also in a liquid state, and the 'liquid-liquid' magnesium thermal reaction is superior to other 'solid-liquid' magnesium thermal reactions, so that the magnesium thermal reaction is carried out at 700 ℃, the reaction can be fully carried out, and a composite uniform porous silica ink structure is obtained.
(6) The invention designs and develops a simpler and greener synthesis method to prepare the porous silicon-carbon composite which has high reversible capacity and excellent cycle performance when used as the lithium ion battery cathode material, and the method for preparing the high-performance silicon-carbon cathode material, which has low cost, easy operation and large-scale production, is beneficial to the development of the next generation of lithium ion batteries.
Drawings
FIG. 1 is a scanning electron microscope image of a porous silicon graphite composite material prepared in example 1 of the present invention;
FIG. 2 is an XRD spectrum of the porous silicon graphite composite material prepared in example 1 of the present invention;
FIG. 3 is a transmission electron microscope image of the porous silicon graphite composite material prepared in example 1 of the present invention;
FIG. 4 is a graph of electrochemical cycle performance of the porous silicon graphite composite material prepared in example 1 of the present invention;
FIG. 5 is a graph showing the adsorption and desorption curves and the pore size distribution curve of the porous silicon graphite composite material prepared in example 1 of the present invention;
fig. 6 is a thermogravimetric analysis chart of the porous silicon graphite composite material prepared in example 1 of the present invention.
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, in the embodiments of the present invention described below, the technical features may be combined with each other as long as they do not conflict with each other.
The silicon-carbon composite material provided by the invention comprises three-dimensional through porous silicon and lamellar graphite, wherein the three-dimensional porous silicon is positioned between the lamellar graphite to form a sandwich structure, the porous silicon grows along the graphite and has a three-dimensional through hole structure, the particle size of the porous silicon is 1-5 micrometers, the thickness of the lamellar graphite is 10-20 nanometers, and the size of the lamellar graphite is about 5-10 micrometers. The size of macropores, namely the pore structure of porous silicon, of the composite material is 50-200 nanometers, and the size of a mesoporous structure is 2-6 nanometers. The composite material comprises 20-80% of silicon by mass and the balance of carbon. The tap density of the composite material is 0.87-0.96 g/cm3The compaction density is 1.36-1.54 g/cm3The specific surface area is 120-150 m2g-1。
The preparation method of the silicon-carbon composite material is characterized by comprising the following steps:
(1) and (3) mixing the silicate glass powder and the lamellar carbon material, then carrying out wet ball milling, filtering and drying to obtain a uniformly mixed mixture of the silicate glass powder and the lamellar carbon material.
According to a preferable technical scheme, the particle size of the silicate glass powder is 5-10 micrometers. The method for obtaining the silicate glass powder comprises the following steps: washing and drying the glass by deionized water, then reducing the particle size of the glass by a mechanical ball milling method, sieving by a 1000-mesh sieve, and screening out glass powder with the particle size meeting the requirement, so that the glass is compounded more uniformly in the subsequent preparation process. The silicate glass is sodium silicate glass or calcium silicate glass.
The lamellar carbon material is a carbon material with a lamellar structure, comprises one or more of natural graphite, artificial graphite or expanded graphite, preferably expanded graphite, has extremely strong pressure resistance, flexibility, plasticity and compatibility, and can be well compounded with silicon materials to form the electrode material. The mass ratio of the silicate glass powder to the lamellar carbon material is 10: 0.5-2. The wet ball milling time is 6-12 hours, and the solvent is preferably alcohol.
(2) Mixing the silicate glass powder obtained in the step (1) with a mixture of a lamellar carbon material, magnesium powder and molten salt, compacting into ingots, and then carrying out a magnesiothermic reduction reaction in an inert atmosphere; and carrying out acid washing treatment on the reaction product to obtain the silicon-carbon composite material.
Wherein, as a preferable scheme, the mass ratio of the mixture of the silicate glass powder and the lamellar carbon material, the magnesium powder and the molten salt is 1: 0.3-0.4: 3 to 5. The molten salt is one or more of magnesium chloride, sodium chloride and potassium chloride, and is preferably a mixture of sodium chloride and potassium chloride in equal mass proportion. The pressure range adopted by compacting into ingots is 10-50 MPa, and the magnesium thermal reduction reaction conditions are as follows: heating to 600-800 ℃ at a heating rate of 2-10 ℃/min in an argon atmosphere, and preserving the heat for 3-6 h. The temperature of the magnesium thermal reaction is preferably 700 ℃, so that reactants react in a molten state and have larger volume density after cooling and solidification. The pressure range adopted by the method for compacting into ingots is 10-50 MPa, and a complete columnar ingot cannot be obtained when the pressure range is lower than or exceeds the pressure range, so that the integral collapse is caused; mixing and compacting the reactant and the molten salt together, and carrying out thermal reaction to obtain a compact porous silica ink stick, wherein the tap density and the compacted density of the compact porous silica ink stick are not lower than the level of the current commercial graphite; the compaction into ingots may be accomplished by hydraulic presses, cold extruders or other pressure equipment. On the other hand, the pressure also directly influences the specific surface area of the finally prepared silicon-carbon composite material, the pore volume in the composite material is reduced along with the increase of the pressure, the specific surface area of the composite material obtained in the pressure range is not too high or too low, and the composite material can meet the requirement of the negative electrode material on the specific surface area when used for the negative electrode material of the lithium ion battery.
The pickling step specifically comprises: and cleaning the porous silica ink in 0.5mol/L hydrochloric acid for 8-12 h under the condition of stirring, then cleaning the porous silica ink in 0.5mol/L hydrofluoric acid, and drying to obtain the porous silica ink composite product.
Carbonizing the mixture of the silicate glass powder and the lamellar carbon material in the step (2), and then mixing the mixture with the magnesium powder and the molten salt; the carbonization treatment preferably comprises the following specific steps: heating the mixture to 800-1200 ℃ at a heating rate of 1-10 ℃/min in an argon environment, preserving heat for 1-3 h, annealing and crushing. The carbonization treatment is used for making the lamellar carbon material graphitized as much as possible and removing organic functional groups on the surface of the carbon material.
The invention actually discloses a method for preparing a silicon-carbon negative electrode material by taking silicate-based glass as a raw material, which comprises the following steps: grinding silicate-based glass by mechanical ball milling, then using alcohol as solvent to mix glass powder and graphite according to a certain proportion, filtering and drying to obtain uniform mixed product of glass and graphite, then carbonizing the obtained sample at a certain temperature in argon environment, grinding and milling the annealed sample, uniformly mixing magnesium powder and molten salt according to a certain proportion, compacting into ingot, and reacting under inert gas (M)xSiO3+2Mg＝2MgO+Si+MxO, M ═ Na, Ca, Al), followed by acid washing of the reaction product to obtain a sandwich-like porous silicon/graphene-like structure composite material. The method has simple and easy steps, wide raw material sources and low price, and most importantly, the mixture is made into ingots through a simple hydraulic process and then subjected to magnesium thermal reaction, so that the tap density of the silicon-carbon negative electrode material is greatly increased, the volume specific capacity of the negative electrode material is improved, and the obtained porous silicon structure with the three-dimensional cross-linked structure can effectively relieve the lithium ion de-intercalationIn the process, the volume of the silicon material expands, and the silicon material is compounded with carbon materials such as graphite to form a structure similar to a sandwich structure, so that the electronic conductivity of the material is effectively improved, and the compatibility of the silicon-based material and an electrolyte is improved, so that the cycle performance and the rate capability of the material are improved, and the silicon-based material can be applied to a lithium ion battery cathode material with high power density and high energy density. Large volume change of silicon during lithium ion intercalation and deintercalation (>300%) causes electrode pulverization and electric contact between silicon and a current collector to be reduced, which leads to poor conductivity and reduced utilization rate of silicon, while the carbon material has higher electronic conductance, provides a better electronic channel for the composite material, and simultaneously can alleviate stress change caused by volume deformation of the silicon material after the carbon and the silicon material are compounded; in addition, the lamellar carbon material can effectively stabilize the interface between the electrode material and the electrolyte, so that an SEI film can stably grow, and the characteristics are beneficial to improving the electrochemical performance of the silicon cathode.
The porous silicon/graphite composite material is prepared by wet ball milling, high-temperature annealing (carbonization) and compaction into ingots through a low-temperature magnesiothermic reduction reaction. The silicon material and the carbon material are fully mixed and uniformly distributed by wet ball milling; then carrying out carbonization treatment to graphitize the carbon material and remove organic functional groups on the surface of the carbon material; the processed and uniformly mixed mixture of the glass powder and the carbon material is mixed with magnesium powder and molten salt, and is compacted into ingots under the action of mechanical force, then magnesium thermal reaction is carried out under inert gas, silicate glass, the molten salt and the magnesium powder react in a liquid state, and after acid cleaning, a silicon-carbon composite material with a similar sandwich structure is formed in situ.
According to the preparation method of the silicon-carbon composite material, silicate glass is used as a silicon source in the silicon-carbon composite material, and the silicate glass participating in magnesium thermal reaction can exist in a liquid state, so that the applicant of the invention creatively proposes that silicate glass powder and a carbon material are uniformly mixed and then are compacted into ingots before the magnesium thermal reaction, and then the magnesium thermal reaction is carried out, so that the density of the finally obtained silicon-carbon composite material is improved, and the energy volume density and the power energy density of the finally obtained silicon-carbon composite material are obviously improved when the silicon-carbon composite material is finally applied to a battery cathode material. The steps in the preparation method of the silicon-carbon composite material can not change the order, and the steps are cooperated to form an independent and complete technical scheme together, so that the silicon-carbon composite material with high tap density and compacted density, high specific mass capacity and specific volume capacity, limited electrode expansion and excellent cycling stability can be obtained finally.
The following are examples:
example 1
(1) Performing ball milling on the glass powder of 5-10 microns and the expanded graphite according to a mass ratio of 10: 1, taking alcohol as a ball milling agent, putting the ball milling agent into an agate tank, and mechanically milling for 10 hours to obtain a mixture of glass and graphite;
(2) heating the mixture of the glass and the graphite obtained in the step (1) to 1000 ℃ at a heating rate of 5 ℃/min under an argon environment, and preserving heat for 2h for carbonization treatment;
(3) grinding and grinding the sample obtained in the step (2), and mixing magnesium powder and molten salt according to a mass ratio of 1: 0.35: 4, uniformly mixing, and then, hydraulically pressing into ingots under the pressure of 40 MPa;
(4) putting the sample ingot obtained in the step (3) into a tubular furnace filled with argon, heating to 700 ℃ at a heating rate of 5 ℃/min, and preserving heat for 3h to obtain a reacted mixture;
(5) and (3) washing the reacted mixture obtained in the step (4) in 1mol/L hydrochloric acid for 5 hours. And then cleaning the porous silicon/graphite composite material in 0.5mol/L hydrofluoric acid for 10 minutes, and pickling to obtain the porous silicon/graphite composite material.
As can be seen from the scanning electron microscope image in fig. 1, the silicon prepared in this embodiment is porous silicon with a three-dimensional penetrating structure, which grows along a graphite sheet at a level of 1 to 5 micrometers, and the porous silicon is a bulk structure with connected particles, and since a reactant is molten in a magnesium thermal reaction process and can permeate into a graphite layer, silicon generated in a reduction process is left between the graphite layers, and the size of the graphite sheet is 5 to 10 micrometers, in fig. 1, it can be clearly seen that the graphite sheet and the porous silicon are uniformly compounded to form an interlayer.
As can be seen from the XRD diffraction pattern of FIG. 2, the three intensity peaks at 28.4 °, 47.3 ° and 56.1 ° correspond to the three intensity peaks of silicon (JCPDS No.27-1402), and the G peak of graphite is distinct and substantially free of impurity phases.
As can be seen from the transmission electron microscope image in fig. 3, the three-dimensional porous silicon in the silicon-carbon composite material prepared in this embodiment is located between the graphene-like sheets to form a sandwich-like sandwich structure, the thickness of the graphite sheet is between 10 nm and 20 nm, and the inset in the upper left corner of fig. 3 shows that the porous silicon has an excellent pore structure and is integrally communicated with each other without damage, and the pore diameter is 50 nm to 200 nm. The structure well relieves the volume expansion in the charging and discharging processes, increases the conductivity and can reveal the reason of excellent performance.
The porous silicon shown in FIG. 4 has excellent electrochemical cycling performance, still has higher capacity (850mAh/g) after 100 cycles, and has good cycling stability, so the invention can be industrially produced and applied in a large scale.
As shown in FIG. 5, the specific surface area of the sandwich-like porous silicon/graphene-like structure composite material is 130m2g-1Wherein the pore diameter of the mesoporous is 2-6 nanometers. The tap density of the porous micron silicon/graphite composite material is tested to be 0.96g/cm3The compacted density is 1.42g/cm3The porous silicon/carbon composite material synthesized by the method has an ultra-high specific surface area and an excellent pore structure, and is suitable for a lithium battery cathode material.
As can be seen from the thermogravimetric analysis in FIG. 6, the carbon content of the composite material is 55 wt%, and the silicon content is 45 wt%.
Example 2
(1) Performing ball milling on the glass powder of 5-10 microns and the expanded graphite according to a mass ratio of 10: 0.8, taking alcohol as a ball grinding agent, putting the ball grinding agent into an agate tank, and mechanically grinding for 10 hours to obtain a mixture of glass and graphite;
(2) heating the mixture of the glass and the graphite obtained in the step (1) to 850 ℃ at a heating rate of 5 ℃/min under an argon environment, and preserving heat for 2h for carbonization treatment;
(3) grinding and grinding the sample obtained in the step (2), and mixing magnesium powder and molten salt according to a mass ratio of 1: 0.35: 5, uniformly mixing, and then hydraulically pressing into ingots under the pressure of 12 MPa;
(4) putting the sample ingot obtained in the step (3) into a tubular furnace filled with argon, heating to 700 ℃ at a heating rate of 5 ℃/min, and preserving heat for 3h to obtain a reacted mixture;
(5) and (3) washing the reacted mixture obtained in the step (4) in 2mol/L hydrochloric acid for 3 hours. And then cleaning the porous silicon/graphite composite material in 0.2mol/L hydrofluoric acid for 30 minutes, and carrying out acid cleaning to obtain the porous silicon/graphite composite material.
Example 3
(1) Performing ball milling on the glass powder of 5-10 microns and the expanded graphite according to a mass ratio of 10:0.5, taking alcohol as a ball milling agent, putting the ball milling agent into an agate tank, and mechanically milling for 8 hours to obtain a mixture of glass and graphite;
(2) heating the mixture of the glass and the graphite obtained in the step (1) to 800 ℃ at a heating rate of 3 ℃/min under an argon environment, and preserving heat for 1h for carbonization treatment;
(3) grinding and grinding the sample obtained in the step (2), and mixing magnesium powder and molten salt according to a mass ratio of 1: 0.3: 4, uniformly mixing, and then performing hydraulic pressing under the pressure of 10MPa to form ingots;
(4) putting the sample ingot obtained in the step (3) into a tubular furnace filled with argon, heating to 600 ℃ at a heating rate of 5 ℃/min, and preserving heat for 6h to obtain a reacted mixture;
(5) the reacted mixture obtained in step (4) was washed in 0.5mol/L hydrochloric acid for 10 hours. And then cleaning the porous silicon/graphite composite material in 0.1mol/L hydrofluoric acid for 60 minutes, and carrying out acid cleaning to obtain the porous silicon/graphite composite material.
Example 4
(1) Performing ball milling on the glass powder of 5-10 microns and the expanded graphite according to a mass ratio of 10: 1, taking alcohol as a ball milling agent, putting the ball milling agent into an agate tank, and mechanically milling for 8 hours to obtain a mixture of glass and graphite;
(2) heating the mixture of the glass and the graphite obtained in the step (1) to 850 ℃ at a heating rate of 10 ℃/min under an argon environment, and preserving heat for 1h for carbonization treatment;
(3) grinding and grinding the sample obtained in the step (2), and mixing magnesium powder and molten salt according to a mass ratio of 1: 0.5: 5, uniformly mixing, and then performing hydraulic pressing under the pressure of 20MPa to form ingots;
(4) putting the sample ingot obtained in the step (3) into a tubular furnace filled with argon, heating to 750 ℃ at a heating rate of 10 ℃/min, and preserving heat for 4h to obtain a reacted mixture;
(5) the reacted mixture obtained in step (4) was washed in 3mol/L hydrochloric acid for 1 hour. And then cleaning the porous silicon/graphite composite material in 0.4mol/L hydrofluoric acid for 20 minutes, and pickling to obtain the porous silicon/graphite composite material.
Example 5
(1) Ball-milled glass powder of 5-10 microns and artificial graphite are mixed according to the mass ratio of 10: 1.5, taking alcohol as a ball grinding agent, putting the ball grinding agent into an agate tank, and mechanically grinding the ball grinding agent for 10 minutes to obtain a mixture of glass and graphite;
(2) heating the mixture of the glass and the graphite obtained in the step (1) to 1000 ℃ at a heating rate of 5 ℃/min under an argon environment, and preserving heat for 1h for carbonization treatment;
(3) grinding and grinding the sample obtained in the step (2), and mixing magnesium powder and molten salt according to a mass ratio of 1: 0.4: 5, uniformly mixing, and then performing hydraulic pressing under the pressure of 30MPa to form ingots;
(4) putting the sample ingot obtained in the step (3) into a tubular furnace filled with argon, heating to 750 ℃ at a heating rate of 5 ℃/min, and preserving heat for 3h to obtain a reacted mixture;
(5) and (3) washing the reacted mixture obtained in the step (4) in 2mol/L hydrochloric acid for 10 hours. And then cleaning the porous silicon/graphite composite material in 1mol/L hydrofluoric acid for 5 minutes, and carrying out acid cleaning to obtain the porous silicon/graphite composite material.
Example 6
(1) And (3) performing ball milling on the glass powder of 5-10 microns and natural graphite according to a mass ratio of 10: 2, taking alcohol as a ball milling agent, putting the ball milling agent into an agate tank, and mechanically milling the ball milling agent for 12 hours to obtain a mixture of glass and graphite;
(2) heating the mixture of the glass and the graphite obtained in the step (1) to 1200 ℃ at a heating rate of 10 ℃/min under an argon environment, and preserving heat for 2h for carbonization treatment;
(3) grinding and grinding the sample obtained in the step (2), and mixing magnesium powder and molten salt according to a mass ratio of 1: 0.35: 3, uniformly mixing, and then performing hydraulic pressing under the pressure of 50MPa to form ingots;
(4) putting the sample ingot obtained in the step (3) into a tubular furnace filled with argon, heating to 800 ℃ at a heating rate of 5 ℃/min, and preserving heat for 6h to obtain a reacted mixture;
(5) the reacted mixture obtained in step (4) was washed in 1.5mol/L hydrochloric acid for 5 hours. And then cleaning the porous silicon/graphite composite material in 0.5mol/L hydrofluoric acid for 30 minutes, and carrying out acid cleaning to obtain the porous silicon/graphite composite material.
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 (11)
1. The preparation method of the silicon-carbon composite material is characterized by comprising the following steps:
(1) mixing silicate glass powder and lamellar carbon materials, performing wet ball milling, performing solid-liquid separation, and drying to obtain a uniformly mixed mixture of the silicate glass powder and the lamellar carbon materials; the lamellar carbon material is a carbon material with a lamellar structure and comprises one or more of natural graphite, artificial graphite or expanded graphite;
(2) carbonizing a mixture of the silicate glass powder and the lamellar carbon material obtained in the step (1), mixing the mixture with magnesium powder and molten salt, compacting the mixture into ingots, and carrying out a magnesiothermic reduction reaction in an inert atmosphere; carrying out acid washing treatment on the reaction product to obtain a silicon-carbon composite material; the silicon-carbon composite material comprises porous silicon and laminated graphite, wherein the porous silicon is located between the laminated graphite to form a sandwich structure, and the porous silicon has a three-dimensional through hole structure.
2. The method according to claim 1, wherein the silicate glass powder has a particle size of 5 to 10 μm.
3. The production method according to claim 1, wherein the lamellar carbon material is expanded graphite.
4. The method according to claim 1, wherein the mass ratio of the silicate glass powder to the lamellar carbon material in the step (1) is 10:0.5 to 2.
5. The method according to claim 1, wherein the carbonization treatment comprises the following specific steps: heating the mixture to 800-1200 ℃ at a heating rate of 1-10 ℃/min in an argon environment, preserving heat for 1-3 h, annealing and crushing.
6. The method according to claim 1, wherein the mass ratio of the mixture of silicate glass powder and lamellar carbon material, magnesium powder and molten salt in step (2) is 1: 0.3-0.4: 3 to 5.
7. The method according to claim 1, wherein the pressure for compacting into an ingot in step (2) is in the range of 10 to 50 MPa.
8. The method of claim 7, wherein the compacting into an ingot is accomplished using a press.
9. The method of claim 8, wherein the press is a hydraulic press or a cold press.
10. A silicon-carbon composite material produced by the production method according to any one of claims 1 to 9.
11. Use of the silicon carbon composite material according to claim 10 as a negative electrode material for lithium ion batteries.
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| CN108448077B (en) * | 2018-02-09 | 2020-07-07 | 武汉科技大学 | Method for preparing Si/C composite material by using oil shale waste residues as raw materials |
| CN110197895A (en) * | 2018-02-26 | 2019-09-03 | 华为技术有限公司 | A kind of composite material and preparation method |
| WO2019169019A1 (en) | 2018-02-28 | 2019-09-06 | The Regents Of The University Of California | Silicon lithium ion electrode materials |
| CN110746817A (en) * | 2018-07-20 | 2020-02-04 | 安徽省绩溪旭龙山庄四宝文化有限公司 | Fragrant ink stick and preparation method thereof |
| CN111370656B (en) * | 2018-12-26 | 2021-12-17 | 国家纳米科学中心 | Silicon-carbon composite material and preparation method and application thereof |
| CN111439934A (en) * | 2020-03-17 | 2020-07-24 | 苏州擎坤环保科技有限公司 | Preparation method of porous graphene-glass composite electrode |
| CN112038616B (en) * | 2020-07-25 | 2021-09-21 | 山东大学 | Oxidation grinding preparation method and application of carbon group element simple substance material |
| CN114122335B (en) * | 2020-08-27 | 2023-07-25 | 中国科学院福建物质结构研究所 | Silicon-carbon composite material and preparation method and application thereof |
| CN114373890B (en) * | 2021-12-01 | 2024-04-02 | 万向一二三股份公司 | Lithium ion battery |
| WO2024003690A1 (en) | 2022-06-27 | 2024-01-04 | Talga Technologies Limited | Method for the production of a silicon-graphite composite material |
| CN115986124B (en) * | 2023-03-15 | 2023-06-09 | 河北坤天新能源股份有限公司 | Silicon-carbon composite material for lithium ion battery and preparation method thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017099523A1 (en) * | 2015-12-10 | 2017-06-15 | 주식회사 엘지화학 | Method for preparing anode active material for lithium secondary battery and lithium secondary battery to which method is applied |
| KR20170090069A (en) * | 2016-01-28 | 2017-08-07 | 성균관대학교산학협력단 | Controlling interlayer distance of graphene-silicon composite and preparing method of the same |
Family Cites Families (6)
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| CN102064322B (en) * | 2010-11-25 | 2013-02-27 | 深圳清研紫光科技有限公司 | Silicon/graphene laminar composite material for lithium ion battery cathode and preparation method thereof |
| CN105047892B (en) * | 2015-08-03 | 2018-07-27 | 中国科学院宁波材料技术与工程研究所 | Porous silica material, preparation method and application |
| CN105762338A (en) * | 2016-02-04 | 2016-07-13 | 天津大学 | Method for preparing lithium battery silicon carbon anode material by utilizing magnesiothermic reduction |
| CN106025280A (en) * | 2016-07-19 | 2016-10-12 | 苏州微格纳米科技有限公司 | Preparation method for graphite and silicon composite anode material |
| CN106450246A (en) * | 2016-12-28 | 2017-02-22 | 江西正拓新能源科技股份有限公司 | Porous silicon-carbon composite material for lithium ion battery and preparation method of material |
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| KR20170090069A (en) * | 2016-01-28 | 2017-08-07 | 성균관대학교산학협력단 | Controlling interlayer distance of graphene-silicon composite and preparing method of the same |
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Application publication date: 20180119 Assignee: Hubei Benxing Carbon Material Co.,Ltd. Assignor: WUHAN University OF SCIENCE AND TECHNOLOGY Contract record no.: X2022420000139 Denomination of invention: A silicon carbon composite material, its preparation method and application Granted publication date: 20200707 License type: Exclusive License Record date: 20221206 |