1237 results about "Silicon particle" patented technology

The invention discloses a silicon-carbon negative electrode material, porous carbon and a preparation method, the porous carbon is prepared by mixing ammonium fluoride and a pre-carbonized material to prepare a premix; and putting the premix in an inert atmosphere, and carrying out pre-activation, drying, carbonization, activation and crushing treatment to obtain the composite material. And uniformly depositing the nano silicon particles into the porous carbon skeleton through a mature CVD (Chemical Vapor Deposition) process to obtain the silicon-carbon composite material. Fluorine and nitrogen co-doping modification can increase the defect degree of a carbon skeleton, efficiently relieve mechanical stress accompanied by lithium storage volume expansion of the silicon negative electrode in a micro scale, provide abundant lithium ion transport and mass transfer channels and enhance the conductivity of porous carbon, and ammonium fluoride is used as a supplementary activator besides water vapor, so that the porosity of the porous carbon is further improved, and the conductivity of the porous carbon is improved. An effective space is provided for uniform deposition of silicon, the fluorine-containing carbon layer can induce formation of a high-stability SEI film rich in LiF on the surface of the nano silicon material, and the interface stability and coulombic efficiency of the silicon negative electrode are further improved.

The invention belongs to the technical field of battery materials, and particularly relates to a method for preparing a porous carbon structure containing a sub-nanoscale ionic conduction improvement layer by utilizing atomic layer deposition and application. The invention discloses a porous carbon-silicon negative electrode structure, which is characterized in that a sub-nano-scale ion conduction improvement layer is added between a porous carbon substrate and silicon particles, and the sub-nano-scale ion conduction improvement layer comprises silicon carbide, aluminum phosphide, aluminum nitride, aluminum oxide, lithium phosphate, aluminum phosphate and lithium aluminum phosphate. Meanwhile, the invention also discloses a preparation method of the porous carbon-silicon negative electrode structure, namely, a sub-nano-scale ion conduction improvement layer is deposited on the porous carbon substrate through an atomic layer deposition method, so that the binding force between the sub-nano-scale ion conduction improvement layer and silicon particles and an ion transport channel are increased, and the ion conduction of a vapor deposition silicon-carbon negative electrode material is improved; the polarization of the material is effectively reduced, so that the rate capability of the battery is improved, and the cycling stability of the porous carbon structure battery is improved.

The present invention relates to a porous silicon-carbon composite having a core-shell structure, a preparing method therefor, and an anode active material comprising same, wherein the core comprises silicon particles and the shell comprises two or more carbon layers including a first carbon layer and a second carbon layer, so that the application of the composite as an anode active material for a secondary battery can enhance the discharge capacity, initial efficiency, and capacity retention rate of the secondary battery. In addition, the preparing method for the porous silicon-carbon composite having the core-shell structure enables the mass production through a continuous process with minimized steps.

The invention provides a silicon-carbon composite material as well as a preparation method and application thereof. The silicon-carbon composite material comprises a porous carbon material; the silicon particles are distributed on the surface layer of the porous carbon material and in pore channels in the porous carbon material, the distribution concentration of the silicon particles in the surface layer of the porous carbon material is smaller than that of the silicon particles in the porous carbon material, and the particle size of the silicon particles in the surface layer of the porous carbon material is smaller than that of the silicon particles in the porous carbon material; the silicon dioxide layer is formed on the surface of the silicon particles; and the carbon coating layer is formed on the surface of the silicon dioxide layer. The lithium ion battery prepared by taking the silicon-carbon composite material as a positive electrode active material shows good electrochemical performance, and has relatively high specific capacity, good cycling stability and rate capability.

The invention relates to a catalytically graphitized silicon-carbon composite material, a preparation method thereof and a lithium ion battery. The preparation method comprises the following steps: providing a porous carbon precursor, sequentially carbonizing, activating and pore-forming, pickling, washing to be neutral, passivating to remove impurities, and then crushing and grading to obtain a porous carbon substrate with the particle size D50 of 5-20 microns; adding a graphitization catalyst into the porous carbon substrate for blending, and carrying out heat treatment at 800-1000 DEG C for 2-6 hours for catalytic modification to obtain modified porous carbon; and putting the obtained modified porous carbon into a chemical vapor deposition reaction furnace, and depositing silicon particles to obtain the catalytically graphitized silicon-carbon composite material. Wherein the graphitization catalyst comprises any one or more of potassium ferrate, iron oxide, nickel oxide, boron, aluminum, titanium, Fe-Si alloy and P-Ni alloy. The graphite catalyst is added to perform catalytic graphitization modification on the porous carbon substrate, so that the energy density, the cycle life and the rate capability of the battery are remarkably improved, and the application requirements of the high-performance battery are met.

The invention relates to the technical field of lithium batteries, in particular to a composite binder aqueous solution, a silicon-based negative pole piece and a preparation method and application of the silicon-based negative pole piece. The preparation method of the composite binder aqueous solution comprises the following steps: dissolving a water-based polymer binder and a micromolecular physical crosslinking agent in water, adding pyrrole, stirring, adding an initiator, and mixing to obtain the composite binder aqueous solution. A small molecule physical cross-linking agent is introduced into the water-based polymer binder, and a large number of hydrogen bond binding sites are increased, so that the mechanical property of the binder is remarkably enhanced, and the machinability of the pole piece is further improved. Meanwhile, polypyrrole can be generated in the binder through in-situ polymerization, and the polypyrrole can be tightly coated on the surfaces of the silicon particles through strong interaction between the binder and the silicon particles to form a stable conductive network, so that the charge transfer capability of the electrode is remarkably improved. In addition, the composite binder is also beneficial to formation of a solid electrolyte layer rich in Li-N and participates in formation of a solid electrolyte interface layer, so that the lithium ion transmission capability of the composite binder is further improved.

The invention relates to the technical field of lithium battery negative electrode materials, in particular to a conductive polymer coated silicon-carbon composite material and a preparation method and application thereof.The conductive polymer coated silicon-carbon composite material comprises a porous silicon-carbon material and a conductive polymer, and the pore width of a porous structure in the conductive polymer coated silicon-carbon composite material is smaller than the in-pore width; the porous silicon carbon material comprises porous carbon and silicon particles, the conductive polymer comprises a polymer frame and a conductive material, the conductive material comprises at least one zero-dimensional conductive substance, at least one one-dimensional conductive substance and at least one two-dimensional conductive substance, and the component content of each conductive substance meets the formula: # imgabs0 # mA is the mass percentage of the component A in the whole system, Pc is the mass percentage of the component B in the whole system, and the component B is the mass percentage of the component B in the whole system. A is the mass fraction percolation threshold of the component A in the polymer framework. According to the invention, not only can a screening type structure be effectively constructed, but also the rate capability can be greatly improved, and finally the silicon-carbon composite material with high initial efficiency, low expansion, high cycle stability and excellent fast charging performance is obtained.

The invention discloses a silicon-carbon composite material which comprises porous carbon, silicon-containing particles are distributed on the surface of the porous carbon and in pore channels, the surfaces of the silicon-containing particles are coated with aluminum silicate layers, and the surface of the porous carbon is coated with a carbon layer. The invention also discloses a preparation method of the silicon-carbon composite material, which comprises the following steps: sequentially carrying out vapor deposition on the porous carbon by using silane, aluminum steam and vapor carbon to obtain the silicon-carbon composite material. The invention also discloses an application of the silicon-carbon composite material in a negative electrode material. When the silicon-carbon composite material is used in the lithium ion battery, the initial coulombic efficiency and the capacity retention rate of the lithium ion battery can be improved, and the expansion rate of a pole piece is reduced.

The invention provides a silicon-carbon negative electrode material and a preparation method thereof, a negative electrode plate, an electrode and an electric device, and relates to the field of batteries. The silicon-carbon negative electrode material comprises porous carbon and silicon particles attached to the pore walls of the porous carbon, crystalline phases exist in the silicon particles, the crystallinity of the silicon particles is at least 90%, and the average grain size of the silicon particles is smaller than 4 nm. According to the silicon-carbon negative electrode material, the battery can obtain relatively good cycling stability and high initial coulombic efficiency at the same time.

The invention provides a metal matrix composite microstructure strengthening simulation method and system, and relates to the technical field of composite mechanical property simulation, and the method comprises the following steps: establishing a polycrystalline aluminum matrix atomic model and a spherical silicon nitride particle strengthening phase atomic model unit; embedding the spherical silicon nitride particles into the polycrystalline aluminum matrix according to the target embedding position coordinates, and integrating to generate an atomic scale structure model; according to the method, an embedded atom potential function is adopted to describe interaction among atoms in a polycrystalline aluminum matrix, a Tersoft potential function is adopted to describe covalent bond interaction among atoms in spherical silicon nitride particles, and a Lennard-Jones potential function is adopted to describe interaction among heteroatoms at a Si3N4 / Al interface; based on the interaction potential between atoms, molecular dynamics simulation is adopted for conducting uniaxial stretching simulation on the atomic scale structure model, mechanical property parameters of the particle reinforced metal matrix composite are obtained through calculation, and a visualization method is combined for analyzing the microcosmic strengthening mechanism of the particle reinforced metal matrix composite.

The invention relates to the technical field of castable, and discloses a silicon carbide castable which comprises main materials and auxiliary materials, the main materials comprise 30-70 parts of silicon carbide particles, 5-20 parts of micro powder which is silicon carbide micro powder, 5-20 parts of nano aluminum oxide, 5-20 parts of a phase change material and 5-20 parts of reinforced fibers, and the auxiliary materials comprise a binding agent, an additive, a heat stabilizer, a high-heat-conductivity additive and an antioxidant. The phase-change material is a metal alloy phase-change material, and the reinforcing fiber is 5-20 parts of steel fiber. The binding agent is 10-15 parts of pure calcium aluminate cement, and the additive is 3-5 parts. In the preparation process of the silicon carbide castable, the steel fiber, the metal alloy phase change material and the graphite are added, the overall performance of the silicon carbide castable can be remarkably improved, the steel fiber can remarkably improve the toughness and mechanical strength of the silicon carbide castable, the castable can be effectively prevented from being heated to deform at a high temperature, shrinkage is inhibited, and a good prevention and treatment effect on microcracks is achieved; therefore, the overall stability and durability of the pouring material are improved.

The invention provides a composite silicon-carbon negative electrode material as well as a preparation method and application thereof. The composite silicon-carbon negative electrode material comprises a composite silicon-carbon inner core and a carbon coating layer arranged on the surface of the composite silicon-carbon inner core, the composite silicon-carbon inner core comprises a porous carbon skeleton and nano silicon particles, modified holes are formed in the porous carbon skeleton, graphite microcrystalline layers are arranged around openings of the modified holes, and the nano silicon particles are arranged on the surface of the porous carbon skeleton and in the modified holes. The modified holes are formed in the composite silicon-carbon negative electrode material, silicon particles can be properly deposited in the modified holes, and the graphite microcrystalline layer is arranged around the modified holes, so that the resistivity of the material can be greatly reduced, and the electrical property of the silicon-carbon negative electrode material is improved.

A slurry for use to form or repair a silicon carbide coating is provided. In one aspect, the slurry includes solid particles and a carbonaceous resin. The solid particles include silicon carbide particles, silicon particles, and carbon particles. A method of fabricating a silicon carbide coating is also provided. In one aspect, the method includes applying the slurry, heating the slurry, and forming the silicon carbide coating from the solid particles and the carbonaceous resin. A method of repairing a silicon carbide coating is also provided. In one aspect, the method includes applying the slurry to a damaged region of the silicon carbide coating, heating the slurry, and repairing the silicon carbide coating with the solid particles and the carbonaceous resin in the damaged region.

The invention belongs to the technical field of transmission sheet materials, and aims to solve the problems that the service life of a clutch is affected and even potential safety hazards are caused due to poor comprehensive performance of an existing transmission sheet material for the clutch under the working conditions of high temperature, high stress and the like. In order to achieve the purpose, the invention provides a powder metallurgy transmission sheet material for a clutch and a preparation method of the powder metallurgy transmission sheet material. The powder metallurgy transmission sheet material for the clutch comprises, by mass, 55%-65% of high-purity atomized iron powder, 8%-12% of electrolytic copper powder, 4%-8% of hydroxyl nickel powder, 1.5%-4% of ferromolybdenum powder, 1%-3% of chromium powder, 0.3%-1.5% of lanthanum powder, 1.5%-3.5% of nanometer silicon carbide particles, 0.8%-2% of carbon fibers, 0.5%-1.5% of whisker-shaped aluminum oxide, 0.3%-1% of cellulose nanocrystals, 0.5%-2% of rare earth oxide, 2.3%-6% of a lubricating agent and 0.5%-1.8% of a binding agent. The comprehensive performance of the transmission piece for the clutch is greatly improved, the reliability and durability of the transmission piece in a complex mechanical environment are guaranteed, the service life is prolonged, and the safety risk is reduced.

The embodiment of the invention relates to the field of energy storage, and provides a secondary battery and a preparation method thereof, an energy storage system and electric equipment. The negative electrode active material comprises a silicon-based material, honeycomb porous graphite and a polypyrrole layer, the surface of the honeycomb porous graphite is coated with the polypyrrole layer, the silicon-based material is embedded in pores of the honeycomb porous graphite, and the silicon-based material comprises silicon particles, a poly N-isopropylacrylamide layer and a disulfide bond-containing polyaniline layer. The poly (N-isopropylacrylamide) layer and the disulfide bond-containing polyaniline layer are coated on the surfaces of the silicon particles, the poly (N-isopropylacrylamide) layer is positioned between the silicon particles and the disulfide bond-containing polyaniline layer, and the honeycomb porous graphite comprises a graphite flake and a carbon layer which is positioned on the surface of the graphite flake and is of a honeycomb pore structure. The secondary battery formed by assembling the negative electrode active material disclosed by the invention has relatively high cycling stability, high temperature resistance, rate capability, gram volume and safety.

The invention relates to a silicon-carbon composite material with a porous structure and a preparation method thereof, and the silicon-carbon composite material with the porous structure comprises an N / P co-doped porous carbon skeleton with micropore, mesopore and macropore channel networks, and amorphous or low-crystalline nanometer silicon particles which are uniformly loaded in the porous carbon skeleton and have the average particle size of 15-40nm, the mass percent of silicon in the composite material is 40-60%, and good interface bonding is formed between silicon and carbon. The preparation method mainly comprises the following steps: firstly, preparing an N / P co-doped porous carbon skeleton through a template method in combination with high-temperature carbonization and N / P source co-pyrolysis; and hydrolyzing an organic silicon source in the carbon skeleton to form silicon dioxide, and performing low-temperature metal thermal in-situ reduction to obtain the nano-silicon loaded composite material. Through a unique porous carbon skeleton design and a precise in-situ composite strategy of nano silicon, the prepared material shows high specific capacity, high initial coulombic efficiency and excellent cycling stability and rate capability when being used as a negative electrode of a lithium ion battery.

A silicon-carbon composite of the present invention comprises a lithium silicon composite oxide and carbon, wherein the lithium silicon composite oxide includes silicon particles, silicon oxide, magnesium silicate, and a lithium silicon compound. By comprising two or more carbon layers including a first carbon layer and a second carbon layer, the silicon-carbon composite can improve the performance of a secondary battery, such as slurry stability and initial charge / discharge characteristics, when used as a negative electrode active material of the secondary battery. In addition, the first carbon layer and the second carbon layer of the silicon-carbon composite satisfy specific thickness ranges, and thus, the silicon-carbon composite can further improve the performance of a secondary battery, such as capacity, cycle characteristics, and initial charge / discharge characteristics, when used as a negative electrode active material of the secondary battery.

The present invention relates to a silicon-carbon composite, a preparation method therefor, and an anode active material comprising same. The silicon-carbon composite includes silicon particles, silicon oxides, magnesium compounds, and carbon. As a molar ratio (O / Si) of oxygen (O) atoms to silicon (Si) atoms in the silicon-carbon composite satisfies 0.01 to 0.60, when the silicon-carbon composite is applied to an anode active material, the discharge capacity, initial efficiency, and capacity retention ratio after cycles of a lithium secondary battery may be simultaneously improved.

The invention provides a phenolic resin-based spherical silicon-carbon composite material as well as a preparation method and application thereof, and belongs to the technical field of lithium battery materials. The preparation method comprises the following steps: preparing spherical phenolic resin by adopting a suspension polymerization method, curing to obtain phenolic resin microspheres, preparing porous carbon spheres by taking the phenolic resin microspheres as a carbon precursor in a carbonization and alkali activation manner, carrying out CVD vapor deposition on nano silicon, and carrying out carbon coating to obtain the phenolic resin-based spherical silicon-carbon composite material. The phenolic resin is utilized to form a highly cross-linked network structure after curing, the carbon spheres obtained after carbonization have good mechanical strength and rigidity, the porous structure of the porous carbon spheres provides a volume change buffering structure for nano-silicon, the lithium ion path is shortened, the spherical structure is beneficial to uniform dispersion, nano-silicon particles are prevented from gathering, and the performance of the lithium ion battery is improved. And the porous carbon spheres with high specific surface area can also improve the interface reaction activity, so that the problems of high volume expansion, low conductivity and slow ion diffusivity of silicon are solved.

The invention discloses a lithium ion battery negative electrode with low expansion and low impedance. The lithium ion battery negative electrode comprises a composite current collector and a negative electrode active material coating coated on at least one surface of the composite current collector, the negative electrode active material coating comprises a negative electrode active material, graphene and lithium polyacrylate; the mass ratio of the negative electrode active material to the graphene to the lithium polyacrylate is (90-99): (0.5-5): (0.5-5), the negative electrode active material comprises a silicon carbon material and a coating material layer arranged on the outer surface of the silicon carbon material, and the coating material layer comprises a polypyrrole layer and single-walled carbon nanotubes uniformly distributed in the polypyrrole layer. Compared with the prior art, the lithium ion battery negative electrode provided by the invention has the advantages of low expansion and low impedance, and can effectively inhibit the expansion of silicon particles, reduce the internal resistance of the battery and maintain the structural stability of the electrode.

The invention relates to the technical field of batteries, in particular to a porous carbon material, a silicon-carbon composite material and application of the porous carbon material and the silicon-carbon composite material. According to the porous carbon material, the micropore rate phi, the pore volume Pv and the compressive strength Cs meet the relational expression that (Cs * phi) / Pv is larger than or equal to 550 and smaller than or equal to 1050, and the micropore rate phi gt; and the compressive strength Cs is 600 to 850 MPa. The porous carbon material provided by the invention has high microporosity, and the microporosity phi, the pore volume Pv and the compressive strength Cs of the porous carbon material meet the relation that (Cs.phi) / Pv is more than or equal to 550 and less than or equal to 1050, so that the particle size of silicon particles can be effectively reduced, the absolute expansion of silicon in a carbon matrix is reduced, and the first effect and the cycling stability of the silicon-carbon composite material are improved.

Performance is improved. There is provided a negative electrode material for a battery, in which the negative electrode material includes carbon, sodium tungstate, and silicon particles 33 including silicon, and in the silicon particle 33, a ratio of the amount of Si in Si2p derived from elemental silicon to the amount of Si in Si2p derived from SiO2 in a surface layer when measured by X-ray photoelectron spectroscopy is 3 or more on an atomic concentration basis.

The invention discloses a sodium-ion battery pole piece containing composite nano silicon carbide and a preparation method thereof, and relates to the field of sodium-ion battery pole pieces, the sodium-ion battery pole piece containing composite nano silicon carbide comprises 0.5-5Wt% of nano silicon carbide particles and 0.5-5Wt% of silicon carbide whiskers, and the weight percentage of the nano silicon carbide particles is 0.5-5Wt%; the weight ratio of the nano silicon carbide particles to the silicon carbide whiskers is (1-2): 1. The silicon carbide is added to enhance the thermal conductivity, so that the thermal conductivity of the sodium-ion battery pole piece is enhanced, and the sodium-ion battery is prevented from aging at high temperature.

The invention relates to the technical field of lithium ion battery negative electrode materials, and discloses a preparation method and application of a high-efficiency silicon-carbon composite graphite material, and the preparation method comprises the following steps: S1, carrying out porosity and size regulation and control on silicon particles: carrying out ball milling on industrial-grade silicon powder to obtain nano silicon particles, and carrying out acid etching to form a porous structure; s2, functional surface treatment and interface optimization: introducing functional molecules to the surfaces of the silicon particles and coating a layer of ultrathin SiO2 protective film; and S3, carbon coating and flexible protection layer construction: performing pyrolysis on the porous silicon particles by using a carbon source to form a uniform carbon coating layer which is applied to a lithium ion battery negative electrode material, and the lithium ion battery is used for an electric vehicle, a power grid energy storage system and portable electronic equipment. Through the collaborative design of the flexible protection layer, the double-layer carbon coating and the gradient coating, the technical bottlenecks of the silicon-based negative electrode material in the aspects of long cycle stability, high rate performance and interface chemical stability are systematically solved.

The invention relates to the technical field of electrochemical energy storage devices, in particular to a silicon-carbon negative electrode material, a negative electrode plate, an electrochemical device and an electronic device, and mainly comprises a core material and a coating material, the core material comprises silicon particles, the coating material comprises a porous carbon material doped with indium particles, and the coating material comprises a porous carbon material doped with indium particles. The average pore size of the coating material ranges from 10 nm to 20 nm, and the porosity of the coating material ranges from 35% to 45%. According to the silicon-carbon negative electrode material provided by the invention, the coating material has the effects of buffering and inhibiting silicon volume expansion, so that pulverization of the silicon-carbon negative electrode material is inhibited, and the problem of volume expansion of a battery is solved.

The invention provides an organic functional group modified silicon negative electrode material as well as a preparation method and application thereof, and belongs to the field of battery negative electrode materials. The method comprises the following steps: pre-hydrolyzing a silane coupling agent to obtain a mixed solution; adding a silicon material into the mixed solution to bond a silane coupling agent on the surface of the silicon material to obtain an intermediate; and performing in-situ polymerization on the intermediate, a polymer monomer and an initiator to form a conductive polymer on the surface of the intermediate, thereby obtaining the silicon negative electrode material. The preparation method comprises the following steps: firstly, carrying out condensation reaction on a hydrolyzable functional group of a silane coupling agent and silicon hydroxyl on the surface of the photovoltaic silicon waste after hydrolysis to form chemical bonding; meanwhile, non-hydrolytic functional groups in the silane coupling agent are partially retained on the surfaces of the silicon particles, so that polymerization sites are provided for subsequent polymerization reaction; and then modification of different organic functional groups is realized through simple in-situ polymerization, so that a confinement effect and stress dissipation in a particle expansion process are realized, and huge volume expansion of the silicon particles is relieved.

The invention provides a sidewalk antiskid terrace material and a construction process thereof, and belongs to the technical field of terrace material manufacturing. The sidewalk antiskid terrace material is prepared from the following components: epoxy resin, polysiloxane elastic resin, fluorocarbon resin, modified covalent organic framework nanosheets, boron nitride nanotubes, nano silicon nitride particles, nano silicon dioxide, nano zinc oxide, a modified flame retardant, attapulgite, a curing agent, an accelerant, a flatting agent, a coupling agent and a dispersing agent. According to the sidewalk antiskid terrace material, various high-performance resins are compounded with the nano filler to form a coating with a compact and uniform structure, so that the mechanical strength and wear resistance of the terrace are remarkably improved. In addition, due to the application of the modified flame retardant, the floor has a good flame-retardant effect, and the safety is improved. The whole formula and the construction process are scientific and reasonable, strong adhesion of the coating is ensured, construction is simple and convenient, curing is sufficient, and the coating is suitable for long-term use of outdoor sidewalks and has attractive appearance and practicability.

The invention discloses a preparation method and application of a lithium ion battery silicon-based negative electrode material based on a metal fluoride additive, and relates to a preparation method and application of a lithium ion battery silicon-based negative electrode material. The invention aims to solve the technical problems of poor lithium ion transmission between silicon and electrolyte interfaces of the existing silicon negative electrode and poor SEI mechanical property. The method comprises the following steps: dissolving metal fluoride in a solvent, mixing with silicon particles, finally adding resin, uniformly mixing, evaporating to dryness, and roasting to obtain the lithium ion battery silicon-based negative electrode material based on the metal fluoride additive. The residual capacity of the material is 1300-1450mAh g <-1 > after 200 cycles under the current of 0.2 C and the voltage interval of 0.01-3V. The invention can be used in the lithium ion field.

The invention relates to a negative active material and a preparation method thereof, a negative pole piece and a secondary battery. The negative electrode active material comprises: a core part comprising porous micron silicon particles and titanium dioxide nanowires; the shell part is coated on at least part of the surface of the core part, and the shell part comprises a carbon coating layer and carbon nanotubes dispersed on the carbon coating layer; wherein one ends of at least part of the titanium dioxide nanowires are arranged on the hole walls of the porous silicon particles, and the other ends of at least part of the titanium dioxide nanowires extend out of the porous silicon particles. According to the negative electrode active material provided by the invention, through the synergistic effect among the porous structure of the porous micron silicon particles, the titanium dioxide nanowires, the carbon coating layer and the carbon nanotubes, the structural stability of the negative electrode active material is improved, the volume energy density of the micron silicon material is ensured to be exerted, and the cycle performance and the rate capability of the battery are improved.

The invention discloses a preparation method and application of a carbon-interspersed superfine silicon network composite structure. According to the method, a carbon skeleton with a low specific surface area is used as a carrier, after high-temperature air oxidation pretreatment, nano silicon particles are loaded through vapor deposition or a mixing method, and the battery is assembled for in-situ electrochemical induction. In the induction process, silicon particles are subjected to lithiation fusion-lithium removal bonding to form a continuous network, a carbon phase is interspersed in the continuous network to limit silicon agglomeration, and a double-phase interspersed structure with a silicon network skeleton size of 5-40nm is obtained. According to the embodiment of the invention, as a lithium ion battery negative electrode, the specific capacity reaches 1507mAhg <-1 > under 0.2 Ag <-1 >, the 100-time cycle capacity retention ratio reaches 94.8%, and the 50-time cycle capacity retention ratio of a whole battery matched with LiFePO4 is 98.1%. A high-cost porous carbon carrier is abandoned, the problems of nano silicon agglomeration and side reaction are solved, and the method is compatible with industrial production.