228 results about "Silicon nanoparticle" patented technology

The invention relates to the field of lithium battery negative electrode materials, and particularly discloses a silicon-carbon composite negative electrode material for a lithium ion battery and a preparation method of the silicon-carbon composite negative electrode material. The method comprises the following steps: preparing a porous carbon substrate, and depositing silicon nanoparticles in pores and on the surface of the porous carbon substrate by adopting a fluidized bed chemical vapor deposition process and taking silane as a silicon source to obtain a silicon-carbon core material; continuously carrying out carbon coating on the surface of the silicon-carbon core material in the fluidized bed by taking acetylene as a carbon source to form a carbon coating layer; and leading out the obtained material from the fluidized bed, taking acetylene as a carbon source, and carrying out carbon coating on the surface of the primary carbon coating layer again by adopting the rotary furnace to form a secondary carbon coating layer. According to the preparation method, a porous carbon matrix and double-layer functional carbon coating process is adopted, so that the volume expansion of silicon in the circulation process is remarkably inhibited, the interface side reaction is reduced, and the circulation stability of the material is effectively improved.

The invention relates to the technical field of batteries, in particular to a silicon-carbon negative electrode material, a preparation method thereof and a lithium ion battery. The invention provides a silicon-carbon negative electrode material. The silicon-carbon negative electrode material comprises silicon nanoparticles, a porous carbon skeleton, an amorphous carbon layer and a carbon material array structure, pores of the porous carbon skeleton are filled with the silicon nanoparticles; the amorphous carbon layer is coated on the surface of the porous carbon skeleton; the carbon material array structure vertically grows on the surface of the amorphous carbon layer; the carbon material array structure comprises a carbon nanotube array and / or a graphene array. According to the silicon-carbon negative electrode material disclosed by the invention, the compressive strength and the conductivity of the silicon-carbon negative electrode material are improved by vertically growing the carbon nanotube array and / or the graphene array on the surface; therefore, the cycle performance and the rate capability are improved, and the cycle expansion rate is reduced.

The invention provides a sphere-like silicon-carbon negative electrode material and a preparation method and application thereof, and particularly relates to the technical field of negative electrode materials, the negative electrode material comprises a sphere-like porous carbon skeleton, silicon nanoparticles distributed in the sphere-like porous carbon skeleton, and an amorphous carbon layer coating the surface of the sphere-like porous carbon skeleton, the particle appearance of the sphere-like porous carbon skeleton is of a round irregular or asymmetric polyhedral structure and comprises one or more of a potato shape, an ellipse shape, an olive shape, a long strip shape and a pomegranate shape, the particle of the sphere-like porous carbon skeleton is provided with a plurality of asymmetric faces, fillets are formed between the faces, and the radius of the fillets does not exceed 20 microns. The problem of structural damage of the material under the action of external force such as rolling can be effectively relieved, good mechanical stability is kept, excellent bonding performance can be achieved in the electrode coating process, the ion transmission path of the material is improved, and the electronic conductivity and the lithium ion diffusion performance are improved.

The invention discloses a biosensor for detecting Alzheimer's disease markers as well as a construction method and application thereof, and relates to the technical field of biosensors. The construction method comprises the following steps: after a glassy carbon electrode is cleaned, dropwise adding a RuSi NPs (at) CS compound on the surface of the glassy carbon electrode to obtain a RuSi NPs (at) CS / GCE electrode; and immersing the RuSi NPs coated CS / GCE electrode into a PHL: S double-chain solution, and carrying out an incubation reaction to obtain the biosensor. The RuSi NPs (at) CS compound is obtained by carrying out mixed reaction on ruthenium-silicon nanoparticles and chitosan; pHL: S double chains contained in the PHL: S double-chain solution are obtained by carrying out incubation reaction on carboxyl-activated PHL chains and S chains. The biosensor has the advantages of high accuracy, strong sensitivity, good selectivity and the like, and can be applied to accurate detection of the Alzheimer's disease marker A beta oligomer.

The invention belongs to the field of functional material preparation, and particularly relates to a preparation method of a silicon-yttrium-carbon composite lithium ion battery negative electrode material, which comprises the following steps: (1) dispersing silicon nanoparticles, polyvinylpyrrolidone and yttrium salt in a deionized water solution to form a mixed solution, carrying out ultrasonic vibration dispersion, and then carrying out magnetic stirring in a room temperature air atmosphere; (2) transferring the obtained solution to a glass culture dish, and performing freeze drying in a freeze dryer; (3) transferring the precursor obtained by drying into a crucible, and placing the crucible in a tubular furnace for high-temperature calcination to obtain a silicon-yttrium-carbon composite material; and (4) grinding and mixing the obtained product with sodium alginate, conductive carbon black and deionized water respectively, uniformly coating the surface of a copper foil with the mixture, and then performing drying, slicing and tabletting treatment to obtain a target product. The preparation method is simple in synthesis process, good in electrode cycling stability, stable in structure and excellent in electrochemical performance.

The invention provides a carbon material, application of the carbon material, a silicon-carbon composite material, a negative electrode and a battery, and particularly relates to the technical field of carbon materials and secondary batteries. The carbon material has the characteristics of a porous structure and graphitization at the same time, and has the following characteristics: i) the N2 adsorption pore volume is 0.4-2.0 cm < 3 > / g; ii) the N2 adsorption average pore size is 1.8 to 5.0 nm; and (iii) partial graphitization is carried out, disordered carbon and graphitized carbon are compounded, a diffraction peak P exists between 2theta = 25-30 degrees in an XRD (X-Ray Diffraction) pattern, and the grain size of P calculated according to a Scherrer formula is 2-40 nm. The invention also provides a silicon-carbon composite material, the silicon-carbon composite material comprises a porous carbon material and silicon nanoparticles, the porous carbon material comprises the carbon material provided by the invention, and the silicon nanoparticles are located in pore channels of the porous carbon material. The silicon-carbon composite material provided by the invention has the advantages of high capacity, high first efficiency and high cycle stability when being applied to the lithium ion secondary battery.

The invention relates to the field of lithium battery negative electrode materials, and particularly discloses a high-energy silicon-carbon composite negative electrode material for a lithium ion battery and a preparation process of the high-energy silicon-carbon composite negative electrode material. The preparation method comprises the following steps: mixing resin-based activated carbon and biomass activated carbon with specific pore volume and compressive strength according to a mass ratio of 1: (0.2-0.3) to obtain a porous carbon matrix; depositing silicon nanoparticles on the porous carbon substrate by adopting a fluidized bed chemical vapor deposition process; depositing a thin carbon layer on the surface of the silicon-carbon core material by taking acetylene as a carbon source; and carrying out secondary carbon coating by adopting a rotary furnace to form the silicon-carbon negative electrode material. According to the composite negative electrode material prepared by the process, the resin-based activated carbon is used as a main matrix, so that the influence of more impurities and non-uniform pore structure distribution of biomass activated carbon on the cycling stability and conductivity of the silicon-carbon negative electrode material is reduced, and the problems of volume expansion and conductivity of the silicon-based negative electrode material are solved.

The invention discloses a carbon-silicon negative electrode material, a preparation method thereof and a battery, and belongs to the technical field of carbon-silicon materials. The silicon content in the negative electrode material is 40-70wt%, the specific surface area is less than or equal to 3m < 2 > / g, the micropore volume is less than or equal to 0.001 m < 3 > / g, and the average grain size of silicon grains is less than or equal to 2nm; in a dQ / dV-V curve, h1 / h2 is greater than or equal to 1.5, and h1 and h2 are respectively lithium removal oxidation peak intensities corresponding to 0.28-0.32 V and 0.44-0.48 V. The preparation method comprises the following steps: carrying out surface passivation treatment on a precursor obtained by carrying out nanometer silicon vapor deposition on a carbon base material, and carrying out carbon coating in a rotary kiln, the method is simple, and the obtained negative electrode material has a double-layer coating structure, a relatively low specific surface area and relatively high mechanical strength, and is suitable for large-scale production. And the rapid volume expansion of the buffer silicon nanoparticles in the repeated lithiation / lithium removal process is facilitated, so that the negative electrode material has relatively high capacity and cycle performance.

The invention discloses an ultra-stable anti-bioadhesion coating as well as a preparation method and application thereof, and belongs to the technical field of functional materials. The coating provided by the invention comprises a component A and a component B, the component A comprises nanoparticles, carboxyl silicone oil, a silane coupling agent and a solvent; the component B comprises a base material and a solvent; the nano-particles comprise at least one of silicon nano-particles, iron nano-particles or zinc nano-particles; the base material comprises epoxy resin. Through cooperation of the component A and the component B, the carboxyl silicone oil and the functionalized nanoparticles are combined and embedded into a matrix material, the formed coating can be used for preparing an ultra-stable anti-bioadhesion coating, the stability is good, the durability is good, adhesion of blood components, protein, bacteria, cells and the like can be effectively reduced, and the anti-bioadhesion performance of the coating is improved. The coating and the coating prepared from the coating have good application prospects in implantable medical equipment.

The invention discloses a porous silicon-carbon composite negative electrode material, a one-step preparation method, a lithium ion battery and application, and belongs to the technical field of lithium ion battery materials, the method comprises the following steps: mixing a silicon source, magnesium powder, a carbon source and a soluble pore forming agent to obtain mixed powder; performing high-energy mechanical ball milling on the mixed powder in an inert atmosphere, and performing acid pickling, high-temperature carbonization treatment, cooling, water washing, suction filtration and drying to obtain the porous silicon-carbon composite negative electrode material; the porous silicon-carbon composite negative electrode material comprises a porous shell formed by amorphous porous carbon and a porous core formed by silicon nanoparticles embedded in the porous shell, the mechanical collision energy generated in the high-energy mechanical ball milling process triggers the low-temperature magnesiothermic reduction reaction between the silicon source and the magnesium powder, the carbon source is attached to the surfaces of silicon particles while the silicon particles are generated, and silicon synthesis, carbon coating and pore forming are synchronously achieved. The silicon-based negative electrode has the advantages of high initial coulombic efficiency, high specific capacity, excellent cycle stability and rate capability, and effectively solves the problems of volume expansion and large-scale preparation of the silicon-based negative electrode.

The invention provides a silicon-based material and a preparation method thereof, a lithium ion battery monomer, a battery device and a power utilization device, the silicon-based material comprises a porous carbon matrix and silicon nanoparticles located in pores of the porous carbon matrix, the surface of each silicon nanoparticle is provided with a silicon oxide passivation layer formed through a passivation reaction, the ratio of the ID / IG of the silicon-based material to the ID / IG of the porous carbon matrix before the passivation reaction is (0.95-1.05): 1; the mass multiple of the Si element and the C element in the silicon-based material is recorded as A, the mass multiple of the Si element and the C element before the passivation reaction is recorded as B, and the ratio of A to B is (0.95-1.05): 1. According to the invention, the thermal safety performance, the cycle performance and the rate capability of the lithium ion battery monomer can be improved.

The invention relates to the technical field of lithium battery materials, and particularly discloses a spherical silicon-carbon negative electrode material and a preparation method and application thereof, and the spherical silicon-carbon negative electrode material comprises an inner core and a coating layer coating the inner core; the inner core comprises porous hard carbon doped with nitrogen element and a carbon layer coated outside the porous hard carbon, and silicon nanoparticles are deposited in the porous hard carbon; and the coating layer is a trimethyl aluminum functionalized polyethylene oxide cross-linked network coating layer. The spherical silicon-carbon negative electrode material provided by the invention is coated by the methylaluminum functionalized polyethylene oxide cross-linked network, the coating layer can provide a transmission channel for ions, promote the transmission of the ions and facilitate the enhancement of the lithium storage performance of the negative electrode material, and the high-strength three-dimensional network structure can effectively inhibit the volume expansion of the silicon-carbon negative electrode material, so that the lithium storage performance of the negative electrode material is improved. And the particles are prevented from cracking or powdering.

The invention relates to the field of lithium battery negative electrode materials, and particularly discloses a high-capacity silicon-carbon negative electrode material and a preparation process thereof. The preparation process comprises the following steps: preparing biomass activated carbon with the total pore volume of 1.0-1.3 cm < 3 > / g and the compressive strength of 20-40 Mpa; depositing silicon nanoparticles in pores and on the surface of the porous carbon matrix by adopting a fluidized bed chemical vapor deposition process to obtain a silicon-carbon core material; depositing a thin carbon layer on the surface of the silicon-carbon core material by taking acetylene as a carbon source; and carrying out secondary carbon coating by adopting a rotary furnace to form the silicon-carbon negative electrode material. According to the silicon-carbon negative electrode material prepared by the process, the mechanical stability and the cycling stability of the material are improved; meanwhile, the large-pore-volume porous activated carbon provides sufficient deposition space for the silicon nanoparticles, the reversible capacity is effectively improved, and volume expansion of silicon in the circulation process can be remarkably inhibited.

The invention discloses a porous silicon carbon negative electrode material, a preparation method thereof and a battery. A matrix of the porous silicon carbon negative electrode material is porous carbon, a conductive layer is deposited in pores of the porous carbon, a fast ion layer is deposited on the surface of the conductive layer, a silicon nanoparticle layer is deposited on the outer side of the fast ion layer, and carbon coating layers are deposited on the surface of the porous carbon and among silicon nanoparticles. According to the method, the conductive layer is firstly deposited, then the fast ion layer is deposited, and a Li reaction place is changed from point-to-point contact of silicon particles and porous carbon into surface-to-surface contact of the conductive layer and the conductive ion layer, so that a Li < + > desolvation barrier and electronic impedance of a substrate are greatly reduced.

The invention relates to a monkey pox virus nano vaccine based on an STING agonist and silicon nanoparticles as well as a preparation method and application of the monkey pox virus nano vaccine. The nano vaccine comprises a monkey pox virus antigen, the silicon nanoparticles and the STING agonist, the monkey pox virus antigen is combined to the surface of the silicon nanoparticle through a DogTag-DogCatcher system; the STING agonist is connected to the surface of the monkey pox virus antigen. The monkey pox virus antigen is covalently coupled with the silicon nanoparticles, and the antigen is displayed on the surfaces of the particles in a specific spatial orientation manner, so that the multivalence and accessibility of the antigen are enhanced, the shielding effect of the silicon nanoparticles on epitopes of the antigen is reduced, and the immune response induced by the vaccine is higher than that of a monomer immunogen protein.

The invention discloses a solid-state battery negative electrode material and a preparation method and application thereof, and relates to the technical field of solid-state batteries. The preparation method comprises the following steps: uniformly mixing silicon nanowires, silicon nanoparticles, a carbon nanofiber precursor material and a solvent, preparing a negative electrode material precursor by adopting electrostatic spinning, and carrying out pre-oxidation treatment and carbonization treatment to prepare the solid-state battery negative electrode material, wherein the mass ratio of the silicon nanowires to the silicon nanoparticles is 1: (0.1-4). According to the invention, the silicon nanowires and the silicon nanoparticles are cooperated, and the carbon nanofibers are used as a carrier to form a three-dimensional network structure, so that the diffusion path, anisotropic stress distribution and crushing resistance of Li can be shortened, the cycle performance is improved, and the carbon nanofibers not only improve the mechanical stability of Si in the cycle process, but also provide good conductivity for the electrode. The problems of volume change and low conductivity of the silicon negative electrode material in the use process are effectively solved, and the interface stability of the silicon negative electrode material and a solid electrolyte material is enhanced.

The invention discloses a silicon-carbon composite negative electrode material with silicon coated by porous carbon as well as a preparation method and application of the silicon-carbon composite negative electrode material, silicon nanoparticles (50-100nm) are taken as a core and are uniformly coated by a porous carbon layer derived from a zeolite imidazate framework material to form a core-shell structure (Si-C), and a silicon / carbon dual-phase coexisting composite material is constructed. The material is further doped with Ni, Co or Zn elements in situ, so that the conductivity and the catalytic activity are improved. The preparation method comprises the following steps: (1) carrying out solvothermal synthesis on a Ni / Co / Zn-ZIF precursor; (2) mixing the silicon nanoparticles with a ZIF precursor, and performing gradient carbonization (350-800 / 900 DEG C) to form a carbon-coated silicon structure; and (3) compounding with a conductive agent and a binder to prepare the negative pole piece. The silicon-carbon composite material disclosed by the invention has high silicon loading capacity (40-60wt%), and the first-circle discharge capacity reaches 1650mAh / g. The material is suitable for high-energy-density lithium ion batteries, and has the advantages of simple process, low cost and large-scale production.

A composition of matter includes silicon nanoparticles having nanopores disperse among the silicon nanoparticles, wherein the silicon nanoparticles have an average particle size of less than about 12 nm, and the nanopores have an average size of less than about 10 nm. An anode material includes a micron-sized assembly of silicon nanoparticles having an average particle size of less than about 12 nm, wherein the silicon nanoparticles are spaced by nanopores having average pore size of less than about 10 nm, and wherein the anode material is made by: dispersing the silicon nanoparticles in a solvent; and evaporating the solvent from the silicon nanoparticles to provide an evaporation-induced assembly of the silicon nanoparticles.

The invention belongs to the technical field of lithium ion battery negative electrode materials, and particularly discloses a nanometer silicon / high-entropy alloy oxide / carbon composite lithium ion battery negative electrode material with a honeycomb-like three-dimensional hierarchical nanometer structure and a preparation method of the nanometer silicon / high-entropy alloy oxide / carbon composite lithium ion battery negative electrode material. The preparation method comprises the following steps: respectively adding PVP and silicon nanoparticles into deionized water, and stirring for 12-24 hours; adding oxysalts of iron, nickel, cobalt, chromium and manganese with equal molar weight, stirring for 12-24 hours, and then freeze-drying for 24-48 hours; and finally, putting the freeze-dried product into a tubular furnace, and calcining at high temperature in an inert atmosphere to obtain the composite lithium ion battery negative electrode material. A half battery prepared from the composite lithium ion battery negative electrode material prepared by the method has high initial specific discharge capacity and excellent capacity retention ratio, and the preparation method of the composite material is simple and convenient to operate, low in cost and suitable for large-scale production, and provides a new idea for preparation of a silicon-based composite electrode.

The invention discloses a core-shell structure silicon-based negative electrode material, a preparation method thereof and a lithium ion battery, and the preparation method comprises the following steps: (1) depositing an amorphous silicon oxide layer on the surface of a silicon particle to obtain a first product; (2) coating the first product by utilizing a carbon source and a biomass carbon source, and calcining to obtain a second product; (3) depositing a carbon layer on the outer layer of the second product to obtain core-shell structure carbon-coated silicon nanoparticles; and (4) dispersing and mixing the core-shell structure carbon-coated silicon nanoparticles and a carbon source, and carrying out vacuum drying, roasting, crushing and screening to obtain the core-shell structure silicon-based negative electrode material. The deposition in the step (1) and the deposition in the step (3) are both LPCVD (low pressure chemical vapor deposition). The silicon surface is uniformly coated and modified, and a good ion pathway is constructed, so that the silicon-based negative electrode material which is uniform in coating, small in volume expansion, high in ion transmission capability and good in comprehensive performance is formed.

The invention discloses a silicon-carbon composite material, a preparation method thereof, a negative plate and a lithium ion battery, and belongs to the technical field of lithium ion batteries. When the silicon-carbon composite material is prepared, the carbon nanotubes and the silicon nanoparticles on which the vertical graphene grows are dispersed in a dispersing agent to form dispersion liquid, and the dispersion liquid is subjected to spray drying to obtain the silicon-carbon composite material. The silicon-carbon composite material comprises a core body on which vertical graphene grows and a carbon nanotube coating layer coating the surface of the core body. The silicon-carbon composite material is applied to a battery negative electrode, and the two-dimensional vertical structure of the vertical graphene and the one-dimensional linear structure of the carbon nanotube are effectively compounded, so that the electron and ion transmission rate can be improved, and the probability of deformation or pulverization and falling of a negative electrode plate caused by the volume change of silicon is reduced; furthermore, the rate capability and the cycle performance of the lithium ion battery can be improved.

The invention discloses a long-circulation lithium battery and a preparation method thereof, and relates to the technical field of lithium battery preparation, the long-circulation lithium battery comprises a gradient doped ternary material-spinel composite structure positive electrode material, a designed porous carbon skeleton confined silicon nanoparticle (Si-C) negative electrode material, and a lithium bis (fluorosulfonyl) imide (LiFSI)-based high-concentration electrolyte, the surface of the polyimide (PI)-based composite diaphragm is coated with a boron nitride nanosheet (BNNS) and polydopamine (PDA), and a three-dimensional porous current collector and a gradient porosity electrode are introduced into the battery structure; through gradient doping and composite coating of a positive electrode material, negative electrode porous carbon confinement silicon and pre-lithiation, collaborative optimization of a high-concentration electrolyte, a high-heat-resistance self-repairing diaphragm and design of a three-dimensional porous current collector and a gradient porosity electrode, remarkable improvement of the battery in the aspects of high energy density, ultra-long cycle life, high safety and rapid charge and discharge performance is realized.

The invention provides a spherical silicon-based composite material and a preparation method thereof, a negative electrode and a battery, and relates to the technical field of silicon-based composite materials, the spherical silicon-based composite material comprises phenolic resin microspheres, a conductive agent and silicon nanoparticles, the phenolic resin microspheres are doped with the conductive agent to form a matrix of the spherical silicon-based composite material, and the silicon nanoparticles are doped with the conductive agent to form the spherical silicon-based composite material. The phenolic resin microspheres are of a regular spherical structure, grooves or protrusions or the combination of the grooves and the protrusions are arranged on the outer surfaces of the phenolic resin microspheres, the conductive agent is evenly dispersed in the phenolic resin microspheres, and part of the conductive agent is dispersed on the outer surfaces of the phenolic resin microspheres. The matrix is activated to form porous carbon microspheres with discontinuous porous channels or pores, and the silicon nanoparticles are deposited in the porous channels or pores. The problems that the ion conduction rate of the spherical silicon-based composite material is reduced and the conductivity is reduced can be solved, so that the first efficiency and the cycle stability of the spherical silicon-based composite material are improved.

A silicon-carbon composite material, a negative electrode sheet and a battery. The silicon-carbon composite material comprises a hierarchically porous carbon material, silicon nanoparticles dispersed in pore channels of the hierarchically porous carbon material, and an amorphous carbon layer that coats a surface of the hierarchically porous carbon material, wherein the porous structure of the hierarchically porous carbon material comprises micropores, mesopores and macropores, the pore volume is 0.4 cm3 / g to 1.5 cm3 / g, and the pore volume of the micropores accounts for 60% to 92% of the total pore volume. The silicon-carbon composite material can effectively inhibit the aggregation of the silicon nanoparticles and reduce the phenomenon of stress concentration; and when the silicon-carbon composite material is used as a negative electrode active material for the preparation of a battery, better first-cycle efficiency, a lower expansion rate and a higher cycling stability can be obtained.

Anode material, preparation method therefor, and lithium-ion battery are provided. The anode material includes a porous carbon substrate and silicon, the silicon being dispersed in the pores and / or surface of the porous carbon substrate. The preparation method for the anode material includes: mixing and treating a porous carbon powder and a binder to obtain a porous carbon substrate; and compounding silicon nanoparticles on the porous carbon substrate to obtain the anode material. Adjusting and selecting process parameters allows for reducing the porosity between porous carbon, and further forming a high-density anode material.

The invention provides a silicon-based negative electrode material and a preparation method and application thereof, and particularly relates to the field of negative electrode materials, the negative electrode material comprises an inner core and a coating layer coating the surface of the inner core, the inner core is composed of a porous carbon matrix and silicon nano-particles deposited in pore channels of the porous carbon matrix, the coating layer is a short-range ordered high-texture carbon layer, and the coating layer is a silicon nano-particle coating layer. The thickness of the high-texture carbon layer is 0.5-30 nm, the length-diameter ratio of the carbon lines is 1-10, and the interlayer spacing is 0.33-0.37 nm. According to the technical scheme, through the synergistic effect of the surface oxygen passivation layer and the high-texture carbon coating layer formed at a high temperature, silicon volume expansion is effectively inhibited, side reactions are reduced, and meanwhile the electrode conductivity and cycling stability are remarkably improved.

The invention discloses a silicon-carbon composite film negative electrode material and a preparation method and application thereof, and belongs to the technical field of lithium ion batteries. The silicon-carbon composite film negative electrode material is of a three-layer film structure and comprises a first silicon-carbon composite film, a second silicon-carbon composite film and a third silicon-carbon composite film which are sequentially stacked, wherein the diameter of the silicon-based material in the second silicon-carbon composite film is greater than the diameters of the silicon-based materials in the first silicon-carbon composite film and the third silicon-carbon composite film; the thickness of the second silicon-carbon composite film is larger than that of the first silicon-carbon composite film and that of the third silicon-carbon composite film. The silicon-carbon composite film negative electrode material has a three-layer structure, and by controlling the diameter and content of the carbon nanoparticles in different layers, on the premise of ensuring the capacity, the silicon nanoparticles can be effectively prevented from being separated from the electrode contact, and the capacity attenuation in the charge-discharge cycle process of the battery is relieved.

The invention relates to the technical field of nano-particle preparation, and discloses preparation and application of a hollow porous yolk shell structure silicon-carbon nano-composite material. According to the hollow porous yolk shell structure silicon-carbon nano-particle provided by the invention, a silicon nano-sphere is used as a core, and a hollow layer between a carbon shell layer and the core is based on a carbon-coated porous channel; the volume change of the silicon nanoparticles in the charging and discharging process is fully released, and the mechanism stability of the electrode material is kept; meanwhile, the hollow structure and the porous structure are beneficial to de-intercalation migration of lithium ions in the silicon nanoparticles, and the rate capability is increased; in addition, the carbon coating layer can avoid direct contact between the silicon nanoparticles and an electrolyte, so that the electronic and ionic conductivity of the material is ensured, and the first coulombic efficiency is improved. When the carbon-silicon composite material prepared by the method is used as a negative electrode, the battery capacity is relatively high, and the rate capability is relatively long.

A method for directly coating silicon nanoparticles onto a solid substrate uses a VHFLPP process that collects silicon nanoparticles in a trapping fluid when preparing the silicon nanoparticles and is also characterized in that the solid substrate is immersed in the trapping fluid during collection of the silicon nanoparticles.

The application relates to a composite sodium ion battery anode material and a preparation method and application thereof, and belongs to the technical field of sodium ion batteries. The preparation method comprises the following steps: S1, dissolving polyacrylonitrile and tetrabutyl titanate in a solvent II, uniformly mixing to obtain a shell layer solution; dissolving multi-walled carbon nanotubes and styrene-acrylonitrile copolymer in a solvent III, uniformly mixing to obtain a core layer solution; stirring and heating gallium, silicon and silicon dioxide, then adding a solvent I to obtain gallium-silicon nanoparticles through ultrasonic treatment, adding the gallium-silicon nanoparticles into the core layer precursor solution to obtain an intermediate layer solution; S2, performing three-axis electrostatic spinning on the three solutions through a concentrically shaped channel nozzle to obtain a composite film; and S3, carbonizing the composite film to obtain the composite sodium ion battery anode material. The composite sodium ion battery anode material can make the electrode have high capacity and excellent cycle stability, prolong the service life of the battery, and is a self-healing and self-repairing battery anode.