CN111584838B - Porous silicon/silicon-carbon composite material and preparation method and application thereof - Google Patents

Porous silicon/silicon-carbon composite material and preparation method and application thereof Download PDF

Info

Publication number
CN111584838B
CN111584838B CN202010372862.2A CN202010372862A CN111584838B CN 111584838 B CN111584838 B CN 111584838B CN 202010372862 A CN202010372862 A CN 202010372862A CN 111584838 B CN111584838 B CN 111584838B
Authority
CN
China
Prior art keywords
silicon
composite material
porous silicon
carbon composite
precursor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202010372862.2A
Other languages
Chinese (zh)
Other versions
CN111584838A (en
Inventor
张桥保
陈慧鑫
项奔
安威力
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Xiamen University
Original Assignee
Xiamen University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Xiamen University filed Critical Xiamen University
Priority to CN202010372862.2A priority Critical patent/CN111584838B/en
Publication of CN111584838A publication Critical patent/CN111584838A/en
Application granted granted Critical
Publication of CN111584838B publication Critical patent/CN111584838B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • 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
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/15—Nano-sized carbon materials
    • C01B32/182—Graphene
    • C01B32/184—Preparation
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B33/00—Silicon; Compounds thereof
    • C01B33/02—Silicon
    • C01B33/021—Preparation
    • C01B33/023—Preparation by reduction of silica or free silica-containing material
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • 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
    • H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
    • 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
    • H01M2004/021—Physical characteristics, e.g. porosity, surface area
    • 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
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/027—Negative electrodes
    • 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 preparation method of a porous silicon/silicon-carbon composite material, which comprises the following steps: step 1: placing magnesium silicide and a precursor in a reaction container at a certain distance, wherein the magnesium silicide and the precursor are arranged along the inert gas inlet flow direction of the reaction container; step 2: introducing inert gas into the reaction vessel, heating the reaction vessel to perform a magnesium thermal reaction, and obtaining a porous silicon/silicon-carbon composite material crude product after the reaction is finished; and step 3: and (3) carrying out acid washing, water washing and drying on the porous silicon crude product obtained in the step (2) to obtain the porous silicon/silicon carbon composite material. The invention also discloses the porous silicon or silicon-carbon composite material prepared by the preparation method and application of the porous silicon or silicon-carbon composite material as a lithium ion negative electrode material. The porous silicon or silicon-carbon composite material prepared by the invention has excellent cycle performance and rate capability in a lithium ion battery, and simultaneously has the advantages of simple and easy preparation method, contribution to batch preparation and the like.

Description

Porous silicon/silicon-carbon composite material and preparation method and application thereof
Technical Field
The invention relates to the field of porous silicon and a composite material thereof, in particular to a porous silicon/silicon-carbon composite material and a preparation method and application thereof.
Background
Silicon is the lithium ion battery anode material with the highest specific capacity (4200mAh/g) discovered by people so far, and is the most potential anode material. But silicon also has some bottlenecks in the application of silicon as a negative electrode of a lithium ion battery, and the first problem is that silicon undergoes huge volume expansion in the reaction. Theoretical calculation and experiments can prove that lithium intercalation and lithium deintercalation can cause volume change, and the volume change is 300 percent; so, whatever the material made, it expands 300% at the atomic or nano-scale of silicon, on a microscopic scale. The problem of large volume changes must be considered in the material design. The high specific capacity material is locally problematic mechanically due to volume expansion, and through a series of basic studies, it is proved that the material can crack, and serious shedding is caused. The second problem is that the SEI film on the silicon surface is relatively thick and non-uniform, and is greatly affected by temperature and additives, which may affect the exertion of the entire specific energy in the lithium ion battery. The technical means of silicon-carbon coating and the like can effectively solve the problems of silicon in the application of the lithium ion battery cathode, and in addition, complete surface coating is very important, so that the silicon can be prevented from contacting with electrolyte to generate the consumption of a thick SEI film. The design of the microstructure is also important to maintain efficient electronic contact and rapid ion channel and buffer volume expansion during cycling.
Reducing the size of silicon to nanometer size is an effective way to alleviate the problem of pulverization, cracking due to volume expansion, and magnesiothermic reduction of (2Mg + SiO)22MgO + Si) is also widely applied to the preparation of nano silicon. However, the conventional magnesium thermal method (direct mixing of magnesium powder and silicon precursor) emits a large amount of heat (for Mg (g) (. DELTA.H) (-9.8 kJ/g)silica) Therefore, the sample is sintered and agglomerated, and the shape of the precursor cannot be well maintained. To avoid the short-term, large exotherms of conventional magnesium thermal reactions, a number of processes have been developed. For example, in the document "extreme High Yield Conversion from Low-Cost to High-Capacity Si Electrodes for Li-Ion Batteries" (Advanced Energy Materials 2014:1400622), it is disclosed that under vacuum conditions, magnesium powder is slowly changed into magnesium vapor at a certain temperature, and then reacts with silicon precursor after being brought in by argon gas flow, and the heat release in the reduction process is controlled by the slow release of magnesium powder, so that the sample is prevented from sintering, and uniform nanoparticles are obtained. Also, for example, the document "furniture Synthesis of Si nanoparticles using magnesium nitride reduction and bit carbon composite as a high-performance and for Li ion batteries" (Journal of Power Source 25)2(2014) 144-149) discloses the preparation of silicon nanoparticles (Mg) by uniformly mixing magnesium silicide and silicon oxide and then reacting2Si+SiO22Si +2MgO), magnesium silicide is used to replace magnesium powder as a reducing agent to achieve the effect of magnesium thermal reduction, and the problem of sintering and agglomeration is avoided by using the mode that the reaction has less heat release; as another example, the document "Sea Sand-Derived Magnesium Silicide as a Reactive Precursor for Silicon-Based Composite Electrodes of Lithium-Ion Battery" (electrochemical Acta 245(2017):893-2CO3As molten salt and a carbon source, preparing a carbon-coated porous silicon composite material in one step; for example, in the patent "silicon/carbon composite material and method for preparing the same" (publication No. CN110854359A), a composite material of nano-silicon and carbon is prepared by converting silicon oxide into mesophase magnesium silicide in a magnesium thermal process, and then reacting the intermediate phase magnesium silicide with carbonate by using magnesium silicide as a reaction precursor. However, the porous silicon prepared by the preparation method still has sintering and agglomeration phenomena, the morphology of the precursor cannot be well maintained, the performance of the product is further influenced, and meanwhile, the performance of the existing porous silicon or silicon-carbon composite material is poor and cannot meet the requirements.
Disclosure of Invention
The invention aims to provide a preparation method of porous silicon, which can avoid sintering and agglomeration, can well keep the shape of a precursor and improve the electrochemical performance of a product, and the porous silicon obtained by the preparation method.
Further, another object of the present invention is to provide a method for preparing a silicon-carbon composite material and a silicon-carbon composite material prepared by the same, based on the porous silicon, to further improve the electrochemical properties of the product.
In order to achieve the purpose, the invention provides the following scheme: the preparation method of the porous silicon/silicon-carbon composite material is characterized by comprising the following steps:
step 1: placing magnesium silicide and a precursor in a reaction container at a certain distance, wherein the magnesium silicide and the precursor are arranged along the inert gas inlet flow direction of the reaction container;
further, when preparing porous silicon, the precursor is mesoporous silica spheres;
further, when the silicon-carbon composite material is prepared, the precursor is graphene oxide coated mesoporous silica spheres;
step 2: filling inert gas into the reaction container, heating the reaction container to perform magnesium thermal reaction, and obtaining a porous silicon/silicon-carbon composite material crude product after the reaction is finished;
and step 3: and (3) carrying out acid washing, water washing and drying on the porous silicon crude product obtained in the step (2) to obtain the porous silicon/silicon carbon composite material.
Preferably, the distance between the magnesium silicide and the precursor in the step 1 is 1-20 cm.
Preferably, the mass ratio of the precursor to the magnesium silicide is 1: 1.3-2.0.
Preferably, the particle size of the mesoporous silica spheres is 100nm-1000 nm.
Preferably, the heating mode of the reaction vessel in the step 2 is heating to 750-950 ℃ at a heating rate of 1-10 ℃/min, and the heat preservation time is 1-6 h.
The invention also comprises the porous silicon/silicon-carbon composite material prepared by the preparation method; the obtained porous silicon is spherical particles, the interior and the surface of the particles comprise three-dimensionally penetrated mesoporous channels, the diameter of the particles is 100-1000nm, and the diameter ratio of the particles to the mesoporous channels is 10-50;
the obtained silicon-carbon composite material comprises porous silicon and a carbon shell, wherein the porous silicon is spherical particles, mesoporous channels which are penetrated through in three dimensions are arranged in the particles and on the surfaces of the particles, the particle diameter is 100-1000nm, the ratio of the particle diameter to the mesoporous channels is 10-50, the carbon shell is reduced graphene, the carbon shell is coated outside the porous silicon, and at least one layer of the carbon shell is arranged.
Preferably, the diameter ratio of the particles to the mesoporous channels is 10-30.
Furthermore, the invention also provides application of the porous silicon or silicon-carbon composite material as a lithium ion battery negative electrode material.
By adopting the technical scheme, the porous silicon or silicon-carbon composite material prepared by the method has the beneficial effects that:
(1) the traditional mode of mixing magnesium silicide and a precursor for carrying out magnesium thermal reaction is changed into the mode of spacing magnesium silicide and the precursor (mesoporous silica spheres or graphene oxide coated silica spheres) at a distance, magnesium silicide is slowly decomposed at a certain temperature to release magnesium vapor, and the magnesium vapor is slowly contacted with the precursor to carry out magnesium thermal reaction under the drive of inert gas flow, so that agglomeration and sintering phenomena are effectively avoided, the obtained porous silicon or silicon-carbon composite material can well keep the morphology of the precursor, and the porous silicon or silicon-carbon composite material shows excellent cycle performance and rate performance in a lithium ion battery.
(2) The mesoporous silicon dioxide spheres or the graphene oxide coated mesoporous silicon dioxide spheres are used as precursors, and the obtained porous silicon is in a blackberry shape and has the advantages of high specific surface area, excellent electrochemical performance and the like; meanwhile, the porous silicon is assembled by small nano-silicon, so that the diffusion path of lithium ions is shortened, the mesoporous morphology of mesoporous silica spheres is inherited, the volume expansion in the lithium desorption and insertion process can be effectively buffered, and the high-specific-energy lithium ion battery can be obtained.
(3) When the silicon-carbon composite material is prepared, magnesium thermal reaction is carried out, and graphene oxide is reduced into reduced graphene, so that the reduced graphene obtained by in-situ reduction can improve the conductivity of the material on one hand, and the inherited mesoporous morphology can further relieve volume expansion on the other hand; meanwhile, compared with the traditional process of firstly preparing porous silicon and then coating and reducing graphene, the preparation method effectively reduces the preparation steps, is simple and feasible, and is also beneficial to batch preparation.
(4) The prepared porous silicon and silicon-carbon composite material can greatly buffer the volume change of silicon in the process of lithium desorption and intercalation, and can be applied to the lithium ion battery cathode material with long service life and high rate performance.
Drawings
FIG. 1 is a schematic diagram of the placement of samples of magnesium silicide and mesoporous silica spheres in accordance with an embodiment of the present invention;
FIG. 2 is an XRD spectrum analysis chart of the porous silicon prepared in example 3 and the silicon-carbon composite material prepared in example 5;
FIG. 3 is a BET specific surface area analysis chart of the mesoporous silica spheres prepared in example 1, the porous silicon prepared in example 3, and the silicon-carbon composite material prepared in example 5;
FIG. 4 is a distribution diagram of the pore diameters of the mesoporous silica spheres prepared in example 1, the porous silicon prepared in example 3, and the silicon-carbon composite material prepared in example 5;
fig. 5 is a scanning electron micrograph and a transmission electron micrograph of the mesoporous silica spheres (a) prepared in example 1, the graphene oxide-coated mesoporous silica spheres (b) prepared in example 4, the porous silicon (c) prepared in example 3, and the silicon-carbon composite material (d) prepared in example 5;
FIG. 6 is a graph of electrochemical rate performance of porous silicon obtained by reaction in example 3 and a silicon-carbon composite material in example 5;
FIG. 7 is a graph showing the cycle performance of porous silicon obtained by the reaction in example 3 and a silicon-carbon composite material in example 5.
Detailed Description
The invention is further described with reference to the following drawings and detailed description.
Example 1: preparation of mesoporous silica spheres
Step 1: dissolving 0.6g of hexadecyl ammonium bromide into a solution mixed with 100mL of absolute ethyl alcohol and 240mL of deionized water, and stirring for 30 min;
step 2: dropwise adding 4mL of ethyl orthosilicate into the mixed solution obtained in the step 1, and stirring for 2 hours;
and step 3: centrifuging the sample obtained in the step 2 at 4000rpm, washing the sample for 3 times by using absolute ethyl alcohol, dispersing the sample into 640mL of deionized water at 85 ℃, standing the mixture for 24 hours, and drying the mixture for 48 hours at 25 ℃ to obtain 1.0g of mesoporous silica spheres;
example 2: preparation of magnesium silicide
2.8g of 325-mesh commercial metal silicon powder and 5.04g of 325-mesh metal magnesium powder are mixed uniformly, placed in a 20mL stainless steel tank, kept at 600 ℃ under argon atmosphere for 6 hours, cooled and taken out to obtain about 7.6g of magnesium silicide.
Example 3: preparation of porous silicon
Step 1: taking 0.3g (precursor) of the mesoporous silica spheres obtained in example 1 and 0.39g of magnesium silicide obtained in example 2, which is arranged in a crucible of a reaction vessel at a distance of 1cm (as shown in figure 1), wherein the magnesium silicide is close to the gas inlet end of the inert gas of the reaction vessel, and the mesoporous silica spheres are arranged at the opposite end;
step 2: filling inert gas argon into the reaction container, heating the reaction container to perform a magnesium thermal reaction, wherein the heating mode is heating at a heating rate of 1-10 ℃/min to 750-:
Mg2Si(s)＝2Mg(g)+Si(s)，2Mg+SiO2＝Si+2MgO
obtaining a porous silicon crude product after the reaction is finished;
and step 3: and (3) washing the porous silicon crude product obtained in the step (2) with 1mol of hydrochloric acid to remove byproducts, washing with deionized water and freeze-drying to obtain 0.14g of porous silicon.
Example 4: preparation of graphene oxide-coated mesoporous silica spheres
Step 1: taking 0.3g of the mesoporous silica spheres obtained in the example 1, dispersing the mesoporous silica spheres into 200mL of absolute ethanol solution, ultrasonically dispersing the solution for 1h, and then adding 2mL of coupling agent 3-aminopropyltrimethoxysilane to obtain mesoporous silica spheres with positive charges on the surface;
step 2: taking 40mL of graphene oxide with the concentration of 1.0mg/mL, performing ultrasonic dispersion for 1h, then adding the graphene oxide into the step 1, and finally freezing the solution by using liquid nitrogen and then performing freeze drying; 0.36g of graphene oxide coated mesoporous silica spheres is obtained.
Example 5: preparation of silicon-carbon composite material
This example is different from example 3 in that the precursor mesoporous silica spheres of example 3 are replaced with graphene oxide-coated mesoporous silica spheres, and other steps and reaction conditions are the same as those of example 3.
As can be seen from the XRD pattern analysis in FIG. 2, it is found that the crystal planes (111), (220), (311), (400) and (331) of silicon (JCPDS No.27-1402) correspond to 28.4 °, 47.3 °, 56.1 °, 69.1 ° and 76.4 °, respectively, and no other impurities are found after acid washing.
As can be seen from FIG. 3, the specific surface areas of the mesoporous silica spheres, the porous silicon and the silicon-carbon composite material are 785.6, 224.3 and 200.8m, respectively2As shown in FIG. 4, the pore diameter of the mesoporous silica spheres before the reaction was 3.9nm, and the pore diameter of the porous silica after the reaction was increased to about 10nm because MgO was generated and pores remained after the removal by acid washing.
As shown in fig. 5, the mesoporous silica spheres prepared in example 1 have uniform and spherical particles with a particle size of 200nm (a), the prepared porous silicon (c) and silicon-carbon composite material (d) well inherit the morphology of the precursor, the shape of the porous silicon is similar to that of a blackberry, and the porous silicon is assembled by small nano-silicon.
As shown in fig. 6 and 7, it can be seen that the porous silicon and silicon-carbon composite material has excellent electrochemical rate performance and cycle performance, wherein the porous silicon is cycled for 1000 cycles at a current density of 0.5C (1C ═ 4.2A/g), the specific capacity is still 840mAh/g, the silicon-carbon composite material is still at a specific capacity of 1034mAh/g, the capacity retention rate is 79.5%, and the cycle stability is good. The specific capacity of 497mAh/g still exists under large charge and discharge current (2C), and excellent rate performance is shown. The application of the lithium ion battery cathode material shows good application prospect.
Example 6
The difference between this example and example 3 is: magnesium silicide was replaced with commercial 325 mesh magnesium silicide; the mass ratio of the mesoporous silica spheres to the magnesium silicide is 1: 1.5; in the step 1, the distance between the mesoporous silica spheres and the magnesium silicide is 5cm, and in the step 2, the mesoporous silica spheres are heated to 850 ℃ and stored for 4 hours.
Example 7
The difference between this example and example 5 is: magnesium silicide was replaced with commercial 325 mesh magnesium silicide; the mass ratio of the mesoporous silica spheres to the magnesium silicide is 1: 1.5; in the step 1, the distance between the mesoporous silica spheres and the magnesium silicide is 5cm, and in the step 2, the mesoporous silica spheres are heated to 850 ℃ and stored for 4 hours.
Example 8
The difference between this example and example 3 is: replacing the mesoporous silica spheres with commercial mesoporous silica spheres, wherein the diameter of the commercial mesoporous silica spheres is 200-300 nm; the mass ratio of the mesoporous silica spheres to the magnesium silicide is 1: 1.8; in the step 1, the distance between the mesoporous silica ball and the magnesium silicide is 10cm, and in the step 2, the temperature is heated to 750 ℃ and kept for 6 hours.
Example 9
The difference between this example and example 5 is: replacing the mesoporous silica spheres with commercial mesoporous silica spheres, wherein the diameter of the commercial mesoporous silica spheres is 200-300 nm; the mass ratio of the mesoporous silica spheres to the magnesium silicide is 1: 1.8; in the step 1, the distance between the mesoporous silica ball and the magnesium silicide is 10cm, and in the step 2, the temperature is heated to 750 ℃ and kept for 6 hours.
Example 10
The difference between this example and example 5 is: replacing the mesoporous silica spheres with commercial mesoporous silica spheres, wherein the diameter of the commercial mesoporous silica spheres is 100-200 nm; magnesium silicide was replaced with commercial 200 mesh magnesium silicide; the mass ratio of the mesoporous silica spheres to the magnesium silicide is 1: 2; the distance between the mesoporous silica spheres and the magnesium silicide in the step 1 is 20cm, and the mixture is heated to 950 ℃ in the step 2 and is kept warm for 1 h.
Example 11
The difference between this example and example 5 is: replacing the mesoporous silica spheres with commercial mesoporous silica spheres, wherein the diameter of the commercial mesoporous silica spheres is 100-200 nm; magnesium silicide was replaced with commercial 200 mesh magnesium silicide; the mass ratio of the mesoporous silica spheres to the magnesium silicide is 1: 2; the distance between the mesoporous silica spheres and the magnesium silicide in the step 1 is 20cm, and the mixture is heated to 950 ℃ in the step 2 and is kept warm for 1 h.
Example 12
The difference between this example and example 5 is: replacing the mesoporous silica spheres with commercial mesoporous silica spheres, wherein the diameter of the commercial mesoporous silica spheres is 500-1000 nm; the mass ratio of the mesoporous silica spheres to the magnesium silicide is 1: 1.6; in the step 1, the distance between the mesoporous silica spheres and the magnesium silicide is 20cm, and in the step 2, the mixture is heated to 900 ℃ and is kept warm for 3 hours.
Example 13
The difference between this example and example 5 is: replacing the mesoporous silica spheres with commercial mesoporous silica spheres, wherein the diameter of the commercial mesoporous silica spheres is 500-1000 nm; magnesium silicide was replaced with commercial 200 mesh magnesium silicide; the mass ratio of the mesoporous silica spheres to the magnesium silicide is 1: 1.6; in the step 1, the distance between the mesoporous silica spheres and the magnesium silicide is 20cm, and in the step 2, the mixture is heated to 900 ℃ and is kept warm for 3 hours.
The porous silicon or silicon-carbon composite obtained in the above examples was tested and the results obtained are shown in table 1 below:
table 1 shows the results of the tests on porous silicon or silicon-carbon composites
Figure BDA0002478976230000111
While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (8)

1. The preparation method of the porous silicon/silicon-carbon composite material is characterized by comprising the following steps:
step 1: placing magnesium silicide and a precursor in a reaction container at a certain distance, wherein the magnesium silicide and the precursor are arranged along the inert gas inlet flow direction of the reaction container; the distance between the magnesium silicide and the precursor is 1-20 cm; the mass ratio of the precursor to the magnesium silicide is 1: 1.3-2.0;
when preparing porous silicon, the precursor is mesoporous silica spheres;
when the silicon-carbon composite material is prepared, the precursor is graphene oxide coated mesoporous silica spheres;
step 2: introducing inert gas into the reaction vessel, heating the reaction vessel to perform a magnesium thermal reaction, and obtaining a porous silicon/silicon-carbon composite material crude product after the reaction is finished;
and step 3: and (3) carrying out acid washing, water washing and drying on the porous silicon crude product obtained in the step (2) to obtain the porous silicon/silicon carbon composite material.
2. The method of claim 1, wherein the mesoporous silica spheres have a particle size of 100nm to 1000 nm.
3. The method for preparing a porous Si/Si-C composite material as claimed in claim 1, wherein the heating of the reaction vessel in step 2 is performed by heating to 750-950 ℃ at a heating rate of 1-10 ℃/min, and the holding time is 1-6 h.
4. A porous silicon/silicon-carbon composite material, characterized in that: the preparation method of any one of claims 1 to 3.
5. The porous silicon/silicon-carbon composite material of claim 4, wherein: the porous silicon is spherical particles, the interior and the surface of the particles comprise three-dimensionally penetrated mesoporous channels, the diameter of the particles is 100-1000nm, and the diameter ratio of the particles to the mesoporous channels is 10-50.
6. The porous silicon/silicon-carbon composite material of claim 4, wherein: the silicon-carbon composite material comprises porous silicon and a carbon shell, wherein the porous silicon is spherical particles, mesoporous channels which penetrate through three dimensions are formed in the particles and on the surfaces of the particles, the particle diameter is 100-1000nm, the ratio of the particle diameter to the mesoporous channels is 10-50, the carbon shell is reduced graphene, the carbon shell is coated outside the porous silicon, and at least one layer of the carbon shell is formed.
7. A porous silicon/silicon-carbon composite according to claim 5 or 6, wherein: the diameter ratio of the particles to the mesoporous pore canal is 10-30.
8. Use of the porous silicon/silicon-carbon composite material according to any one of claims 4 to 7 as a negative electrode material for lithium ion batteries.
CN202010372862.2A 2020-05-06 2020-05-06 Porous silicon/silicon-carbon composite material and preparation method and application thereof Active CN111584838B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010372862.2A CN111584838B (en) 2020-05-06 2020-05-06 Porous silicon/silicon-carbon composite material and preparation method and application thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010372862.2A CN111584838B (en) 2020-05-06 2020-05-06 Porous silicon/silicon-carbon composite material and preparation method and application thereof

Publications (2)

Publication Number Publication Date
CN111584838A CN111584838A (en) 2020-08-25
CN111584838B true CN111584838B (en) 2021-03-16

Family

ID=72113210

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010372862.2A Active CN111584838B (en) 2020-05-06 2020-05-06 Porous silicon/silicon-carbon composite material and preparation method and application thereof

Country Status (1)

Country Link
CN (1) CN111584838B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112802957B (en) * 2021-02-01 2023-04-07 河南理工大学 Preparation device and preparation method of porous silicon and magnesium silicide composite material
CN114141998B (en) * 2021-10-20 2023-06-30 合肥国轩高科动力能源有限公司 Preparation method of self-assembled silicon-carbon composite material

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105098160A (en) * 2015-08-31 2015-11-25 中原工学院 Hollow porous graphene-doped carbon/silicon nanofiber lithium battery anode material and preparation method thereof
CN108269989A (en) * 2018-02-09 2018-07-10 武汉科技大学 A kind of carbon coating micron silicon, preparation method and application
CN109244378A (en) * 2017-07-10 2019-01-18 力信（江苏）能源科技有限责任公司 A kind of preparation method of porous nano Si-C composite material
CN110197900A (en) * 2019-06-20 2019-09-03 厦门大学 A kind of Si-C composite material and its preparation method and application

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9728777B2 (en) * 2013-07-26 2017-08-08 Nanoteck Instruments, Inc. Methods for mass-producing silicon nano powder and graphene-doped silicon nano powder
US9774033B2 (en) * 2015-03-27 2017-09-26 Nanotek Instruments, Inc. Process for producing silicon nanowires directly from silicon particles
CN107317012B (en) * 2017-06-28 2020-04-14 山东大学深圳研究院 High-performance Si/C composite material for negative electrode material of lithium ion secondary battery and preparation method thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105098160A (en) * 2015-08-31 2015-11-25 中原工学院 Hollow porous graphene-doped carbon/silicon nanofiber lithium battery anode material and preparation method thereof
CN109244378A (en) * 2017-07-10 2019-01-18 力信（江苏）能源科技有限责任公司 A kind of preparation method of porous nano Si-C composite material
CN108269989A (en) * 2018-02-09 2018-07-10 武汉科技大学 A kind of carbon coating micron silicon, preparation method and application
CN110197900A (en) * 2019-06-20 2019-09-03 厦门大学 A kind of Si-C composite material and its preparation method and application

Also Published As

Publication number Publication date
CN111584838A (en) 2020-08-25

Similar Documents

Publication Publication Date Title
Luo et al. Controllable growth of SnS 2 nanostructures on nanocarbon surfaces for lithium-ion and sodium-ion storage with high rate capability
Sun et al. A hybrid ZnO/Si/porous-carbon anode for high performance lithium ion battery
EP3089242B1 (en) Active material composite particle, electrode active material layer, and all solid lithium battery
CN106848199B (en) Nano-silicon/porous carbon composite anode material of lithium ion battery and preparation method and application thereof
US20230197929A1 (en) Method of making electrodes containing carbon sheets decorated with nanosized metal particles and electrodes made therefrom
Miao et al. Monodispersed SnO2 nanospheres embedded in framework of graphene and porous carbon as anode for lithium ion batteries
CN103000906B (en) Preparation method of foamy copper/carbon nanophase composite negative electrode material for lithium ion battery
CN109755482B (en) Silicon/carbon composite material and preparation method thereof
CN112467108B (en) Porous silica composite material and preparation method and application thereof
Xiao et al. 3D interconnected mesoporous Si/SiO2 coated with CVD derived carbon as an advanced anode material of Li-ion batteries
CN111403701B (en) Preparation method of iron-based compound composite nitrogen-doped graphene sodium ion negative electrode battery material
CN111584838B (en) Porous silicon/silicon-carbon composite material and preparation method and application thereof
Zhao et al. Ge nanoparticles embedded in spherical ordered mesoporous carbon as anode material for high performance lithium ion batteries
Zhang et al. Sequential-template synthesis of hollowed carbon polyhedron@ SiC@ Si for lithium-ion battery with high capacity and electrochemical stability
JP2023550073A (en) Silicon-based particles with core-shell structure and their manufacturing method, negative electrode materials, pole pieces and batteries
CN113690429A (en) Carbon-coated graphene/metal oxide composite material and preparation method thereof
CN112786865A (en) MoS2Preparation method and application of quasi-quantum dot/nitrogen-sulfur co-doped biomass carbon composite nano material
Zhang et al. Novel Si@ C/P anode materials with improved cyclability and rate capacity for lithium-ion batteries
CN116314791A (en) Preparation method of silicon-carbon anode material
CN108807904B (en) Preparation method of modified lithium iron phosphate cathode material for lithium battery
Sun et al. Comparative study of electrochemical performance of SnO2 anodes with different nanostructures for lithium-ion batteries
CN112436131B (en) Method for preparing silicon-carbon composite material by molten salt assisted magnesiothermic reduction
Fang et al. Confined germanium nanoparticles in an N-doped carbon matrix for high-rate and ultralong-life lithium ion batteries
Zhang et al. Preparation of graphene-like carbon attached porous silicon anode by magnesiothermic and nickel-catalyzed reduction reactions
Chang et al. Plasma-processed homogeneous magnesium hydride/carbon nanocomposites for highly stable lithium storage

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant