513 results about "Graphite composite" patented technology

The invention relates to the technical field of image processing, and discloses a graphite composite insulation board production process control method and system and a storage medium. The control method comprises the following steps: carrying out characteristic analysis and proportion optimization on raw materials to obtain pretreated raw materials; and monitoring the reaction state of the pretreated raw material, regulating process parameters, and generating a modified raw material. And performing formula optimization and performance prediction based on the material parameters of the modified raw material to obtain an optimized formula material. And forming process parameters of the optimized formula material are analyzed, a forming process is regulated and controlled, and a forming material is generated. And the curing process is optimized through the state parameters of the forming material, and a cured product is formed. And finally, evaluating the quality according to the detection data of the cured product, and generating a production control scheme. By establishing a multi-dimensional data acquisition and processing system, intelligent control over the whole production process is achieved, and therefore the stability and consistency of product quality are improved.

A graphite composite material and a preparation method therefor, a negative electrode active material, a secondary battery, and an electric device. The graphite composite material comprises an inner core and a coating layer located on the surface of the inner core, wherein the material of the inner core comprises graphite, and the material of the coating layer comprises a nitrogen-doped porous aluminum oxide-carbon composite material. The provided graphite composite material improves the initial efficiency of the graphite material, and improves the rate capability of a battery.

The invention provides anti-cracking and anti-seepage high-performance concrete, which relates to the technical field of concrete and comprises Portland cement, aggregate, a high-activity mineral admixture, a calcium-magnesium composite expanding agent, nano silicon dioxide particles, a microcapsule-packaged sodium silicate and calcium lactate solution, paraffin / expanded graphite composite phase change microspheres, steel fibers, PVA fibers and nano cellulose. The self-repairing concrete has the characteristics that the anti-cracking performance is comprehensively improved, the anti-seepage grade is broken through, the self-repairing capability is long-acting, the construction adaptability is enhanced, and the like.

The invention relates to a silicon-carbon composite material and a preparation method and application thereof.The preparation method comprises the steps that a porous graphite raw material is subjected to acid pickling and smashing to obtain pretreated porous graphite, then the pretreated porous graphite is soaked in a carbon precursor solution in a vacuum mode, carbonization treatment is conducted after centrifugal separation, pores of the porous graphite are filled with carbides, physical activation is conducted, and the silicon-carbon composite material is obtained; the preparation method comprises the following steps: forming pores in a carbide to form a graded pore structure to obtain a porous graphite composite material, then carrying out silicon deposition in a fluidized bed to obtain a uniform nano silicon layer, and then carrying out carbon coating treatment to obtain a silicon-carbon composite material; the graphite with relatively low cost is adopted as a matrix, high capacity and long cycle performance of the graphite-based silicon-carbon negative electrode material are realized through hierarchical pore structure design, carbonization-activation synergistic pore forming and interface deposition process optimization, and the graphite-based silicon-carbon negative electrode material can be applied to the fields of power batteries and high-energy-density energy storage, especially the field of lithium ion batteries and has wide application prospects. The expansion rate of the battery can be reduced, and the specific capacity, cycling stability and safety of the lithium ion battery can be improved.

The invention relates to the technical field of bipolar plates of all-vanadium redox flow batteries, in particular to a modified binary composite bipolar plate for a vanadium battery and a preparation method of the modified binary composite bipolar plate. Performing interface crosslinking on the carbon-coated graphite and the cationic polyelectrolyte under the action of an enhanced silane coupling agent to obtain a pasty filler, and performing primary melt mixing on the resin and a polymer additive in a solvent to obtain the carbon-coated graphite composite material. And carrying out secondary melting on the pasty filler, the compatilizer and the primary mixing product, and carrying out integral compression molding on final mixing particles by using a hot press to obtain the modified binary composite bipolar plate. According to the bipolar plate prepared by the invention, chitosan film coated carbon nanotubes and carbon coated graphite are subjected to interface crosslinking to form a continuous conductive grid, and the conductivity and mechanical strength of the bipolar plate can be effectively improved, so that the efficiency of an all-vanadium redox flow battery stack is improved.

The invention discloses a nanometer silicon filled microcrystalline graphite negative electrode material and a preparation method and application thereof. The preparation method of the nano-silicon filled microcrystalline graphite negative electrode material comprises the following steps: by taking microcrystalline graphite as a base material, depositing silane between sheet layers of the microcrystalline graphite by adopting a gradient heating method to obtain a nano-silicon filled microcrystalline graphite composite material; and finally, forming the nano-silicon filled microcrystalline graphite negative electrode material with a porous structure on the surface of the nano-silicon filled microcrystalline graphite composite material through carbon source coating carbonization. According to the nano-silicon-filled microcrystalline graphite negative electrode material with the core-shell structure provided by the invention, an inner core is a silicon-graphite composite material formed by nano-silicon-filled microcrystalline graphite, nano-silicon particles are filled in the surfaces and gaps of crystalline grains of the microcrystalline graphite, volume expansion of the nano-silicon in the charging and discharging process is inhibited by a microcrystalline graphite matrix material, and particularly, the volume expansion of the nano-silicon in the charging and discharging process is inhibited by the microcrystalline graphite matrix material. And due to different structural orientations of the microcrystalline graphite, the stress effect can be counteracted, and the volume expansion of the material is further inhibited.

The invention discloses a graphite composite material as well as a preparation method and application thereof, and belongs to the technical field of preparation of negative electrode materials. The graphite composite material has a core-shell structure, and the core of the core-shell structure comprises magnetic metal oxide doped porous graphite; and the shell of the core-shell structure comprises a carbon nanotube, a lithium supplement agent and amorphous carbon. The specific capacity is improved by doping the magnetic oxide in the porous graphite, and the carbon nanotube lithium supplement agent amorphous carbon is coated on the porous graphite, so that the energy density and the fast charging performance of the battery are improved.

The invention discloses a lithium salt doped porous carbon coated graphite composite material for an energy storage battery and a preparation method thereof, the composite material has a core-shell structure, the core is graphite, and the shell is a lithium salt doped porous carbon complex. The preparation method comprises the following steps: uniformly mixing amino resin, a pore-forming agent and a heteroatom compound of the pore-forming agent, curing, activating to obtain porous carbon, adding the porous carbon into an inorganic lithium salt, uniformly mixing, and carrying out spray drying to obtain lithium salt doped porous carbon; the preparation method comprises the following steps: adding lithium salt doped porous carbon into a carboxymethyl cellulose lithium solution, uniformly dispersing, then adding into a graphite material, uniformly dispersing, spray-drying, and carbonizing to obtain the lithium salt doped porous carbon coated graphite composite material. According to the obtained material, the coating layer lithium salt is doped with porous carbon, so that the liquid absorption and retention capacity of the material is improved, the diffusion rate of lithium ions is increased, and the rate capability is improved; meanwhile, the expansion of the composite material in the charging and discharging process is reduced by utilizing the low expansion of the porous carbon, and the cycle performance is improved.

The invention relates to the technical field of lithium ion battery negative electrode materials, in particular to a graphite composite material and a preparation method and application thereof. The preparation method comprises the following steps: heating metal lithium to obtain lithium steam, and depositing the lithium steam into a metal organic framework material to obtain a lithium-doped metal organic framework material; a chemical vapor deposition method is adopted, carbon source gas and oxygen are introduced, amorphous carbon is deposited in the lithium-doped metal organic framework material, and an amorphous carbon and lithium co-doped metal organic framework material is obtained; and mixing the amorphous carbon and lithium co-doped metal organic framework material, a metal salt solution and a graphite material to obtain a mixture, heating, carrying out solid-liquid separation, taking solid components, introducing carbon source gas, and reacting to generate carbon nanotubes, thereby obtaining the graphite composite material. When the prepared graphite composite material is applied to a lithium ion battery as a negative electrode material, the battery has the advantages of high first efficiency, good liquid retention performance, low expansion, fast charge, good cycle performance and the like.

The invention discloses a graphite composite material with a functional coating layer, and a preparation method and application thereof, and belongs to the technical field of lithium ion batteries. The graphite composite material with the functional coating layer is a secondary particle formed by bonding single graphite particles with a core-shell structure, wherein the single graphite particles comprise graphite particles and the functional coating layer coating the surfaces of the graphite particles; the functional coating layer comprises a fast ion conductor and a doped element carbon layer. According to the graphite composite material with the functional coating layer disclosed by the invention, secondary particles are formed by coating the surface of the graphite particles with an elemental carbon layer and a fast ion conductor layer, so that the Li < + > diffusion path and the interface diffusion resistance can be shortened, and a surface SEI layer is stabilized; therefore, the high-rate capacity exertion and the long cycle stability of the graphite composite material are remarkably improved.

The invention discloses a MoAlB ceramic particle reinforced copper / graphite composite material and a preparation method thereof. The composite material comprises the following raw materials in percentage by mass: 1-20% of copper-plated graphite powder, 1-20% of MoAlB powder and the balance of pure copper powder and less than 0.01% of inevitable impurities. The preparation process of the composite material comprises the following steps: grinding and mixing the raw materials including the copper-plated graphite powder, the MoAlB powder and the pure copper powder, putting into a mold, sintering, cooling along with a furnace after sintering, discharging, and demolding to obtain the composite material. According to the composite material, on the basis of the synergistic effect among the components of the raw materials, especially the good interface bonding effect between MoB derived from MoAlB and a matrix, the hardness, bending strength, wear resistance and other performance of the composite material are remarkably improved, and the technical problem that ceramic is prone to being separated from the matrix in the material wear process in the prior art is effectively solved.

The invention discloses a high-initial-efficiency fast-charge graphite composite material and a preparation method thereof, the composite material is of a core-shell structure, the core is graphite, and the shell is lithium sulfonate / lithium molybdate and an amorphous carbon coating layer thereof; the mass ratio of the shell is 5-15 wt% according to the mass ratio of the composite material being 100%. The preparation method comprises the following steps: adding a molybdenum compound into a solvent to prepare a solution, adding graphite oxide, an inorganic lithium salt and a carbon nanotube conductive solution, reacting for 2-12 hours at the temperature of 50-120 DEG C, filtering, carbonizing filter residues to obtain a lithium molybdate conductive agent coated graphite material, and depositing a lithium sulfonate derivative on the surface of the lithium molybdate conductive agent coated graphite material by an atomization method to obtain the lithium molybdate conductive agent coated graphite material. The electron and ion conductivity of the material can be improved, and the rate and the first efficiency of the material can be improved.

The invention discloses a silicon carbide power module packaging structure with low thermal resistance and low stress, and belongs to the technical field of semiconductor devices. The packaging structure comprises a metal substrate; the insulating ceramic layer is arranged on the metal substrate; the circuit layer is arranged on the insulating ceramic layer; the lower surface of the silicon carbide chip is connected with the circuit layer through a first interface layer; the composite heat dissipation stress buffer layer is arranged on the upper surface of the silicon carbide chip through a second interface layer; the copper clamp is connected with the upper surface of the composite heat dissipation stress buffer layer through a third interface layer; and the composite heat dissipation stress buffer layer is made of a copper-graphite composite material. According to the invention, the junction temperature of the silicon carbide chip can be greatly reduced, the overall thermal resistance is reduced, the surface stress of the chip is reduced, the warping phenomenon of the chip in the working process is effectively improved, and the long-life reliability of the power module under the long-term thermal cycle working condition is ensured.

The invention discloses a porous silicon-carbon negative electrode material of a lithium ion battery as well as a preparation method and application of the porous silicon-carbon negative electrode material. The preparation method comprises the following steps: firstly, activating silicon nanoparticles by using a surfactant, so that the silicon nanoparticles are positively charged, and agglomeration of the silicon nanoparticles is avoided; secondly, nano active silicon and graphite are uniformly mixed and ball-milled, so that the active silicon is anchored in a graphite layer, and the conductivity of the whole material is improved; and uniformly mixing and ball-milling the silicon / graphite composite material, asphalt and potassium chloride, and then annealing and washing to obtain the porous silicon-carbon composite material. The activated nano silicon can effectively prevent agglomeration of nano silicon particles, the porous carbon prepared by taking potassium chloride as a template agent has the characteristics of environmental protection and no pollution, the potassium chloride can be recycled, and the prepared porous silicon carbon negative electrode material can enable a lithium ion battery to have relatively high initial coulombic efficiency and excellent cycling stability.

The invention belongs to but is not limited to the technical field of gas insulated transmission lines, and discloses a GIL three-pillar grounding electrode copper / graphite system performance optimization method and a GIL three-pillar grounding electrode copper / graphite system performance optimization system. The copper / graphite grounding electrode material is prepared based on a plasma sintering technology, the microstructure morphology, the wear resistance, the conductivity, the Vickers hardness, the heat conductivity and the density of the copper / graphite grounding electrode material are tested, and all the properties of the material are comprehensively evaluated by adopting a radar map evaluation method, so that the grounding electrode material has the considerable conductivity and also has the good wear resistance; a series of equipment faults caused by insufficient wear resistance are reduced, and the optimization of the comprehensive performance of the grounding electrode is realized.

The invention belongs to the field of negative electrode materials, and particularly relates to a silicon-graphite composite material, a preparation method and application thereof and a lithium ion battery, the preparation method comprises the following steps: mixing and slurrying silicon powder, graphite and a composite functional additive, and then carrying out ball milling modification to obtain primary composite particles; the composite functional auxiliary agent comprises an auxiliary agent A, an auxiliary agent B and an auxiliary agent C; the primary composite particles and a carbon source liquid phase are compounded and then subjected to spray drying and heat treatment, or spray pyrolysis is directly carried out, and secondary composite particles are prepared; and carrying out modification treatment on the secondary composite particles prepared in the step 2 in a surface modification liquid, and then carrying out low-temperature annealing at 150-300 DEG C to prepare the silicon-graphite composite material. The surface modification liquid is an organic solution in which conductive lithium salt and an auxiliary agent D are dissolved. Based on the combined control of the preparation process and the structure, the silicon-based negative electrode material with ultra-long cycle life and excellent low-temperature fast charging performance can be obtained.

The invention discloses a preparation method of a graphite composite bipolar plate, which comprises the processes of raw material homogenization, preheating treatment, hot press molding, demolding, stress relief and cutting and trimming, the raw material homogenization and stress relief processes can significantly improve the yield and product quality, and the problems of low yield, poor batch stability and the like in the prior art are solved; meanwhile, conductive fillers such as graphene, carbon fibers, carbon black, carbon nanotubes and metal fibers are introduced, so that a bridging effect among graphite particles is achieved, a conductive path is broken through, contact resistance is reduced, the overall conductivity of the bipolar plate is improved, the mechanical property of the material can be improved, and the service life of the bipolar plate is prolonged. Particularly, the bending strength is obviously improved; in addition, the method is simple in process, flexible to adjust, low in special equipment requirement, low in equipment investment and suitable for popularization.

The invention discloses a solid electrolyte coated porous microcrystalline graphite composite material, a composite negative electrode and a preparation method and application of the composite negative electrode. The solid electrolyte coated porous microcrystalline graphite composite material comprises porous microcrystalline graphite with a porous structure; the particle size compounded inorganic solid electrolyte comprises a gathering part filled in a porous structure, and coating parts distributed among particles of porous microcrystalline graphite and on the surface of the porous microcrystalline graphite. The composite negative electrode comprises a current collector, a solid electrolyte coated porous microcrystalline graphite composite material arranged on the surface of the current collector and metal compounded on the surface of the composite material. The surface of the porous microcrystalline graphite is coated with the compounded solid electrolyte with different particle sizes, so that the ionic conductivity of the material can be greatly improved, and uniform deposition and dissolution of metal are facilitated; and the prepared composite negative electrode has lower expansion, the porous microcrystalline graphite can contribute higher reversible capacity, and the composite negative electrode has the advantages of high capacity and high compaction.

The invention provides a graphite composite material, a preparation method thereof and a secondary battery, and relates to the technical field of lithium ion battery negative electrode materials. The graphite composite material comprises an inner core and a shell layer, the inner core comprises metal element doped metal oxide and graphite, the metal element doped metal oxide is embedded between sheet layers of the graphite, the shell layer comprises multi-walled carbon nanotubes and amorphous carbon, and the multi-walled carbon nanotubes are distributed in the amorphous carbon in a 3D net shape. According to the invention, by introducing the doping element, the lithium intercalation active sites of the metal oxide are increased, so that the lithium storage performance of the graphite composite material is improved; through the construction of a core-shell and intercalation structure, the volume expansion of the metal oxide is inhibited, so that the cycling stability of the graphite composite material is improved.

A graphite composite negative electrode material, a preparation method therefor and an application thereof. A coating layer formed by mixing a plurality of substances is coated on the surface of graphite, the high theoretical specific capacity of titanium niobate is utilized, and carbon nanotubes and amorphous carbon are added in an auxiliary manner, the carbon nanotubes form a network structure, and the amorphous carbon stabilizes the structure of the material, which jointly improve the structural stability of the material in the charging and discharging process, and improve the first efficiency and the cycle performance of the material.

The invention discloses a porous carbon-coated graphite composite material for an energy storage battery and a preparation method of the porous carbon-coated graphite composite material. The porous carbon-coated graphite composite material consists of inner core graphite and lithium heteroatom-doped porous carbon coated on the surface of the inner core graphite, the preparation method comprises the following steps: preparing an organic template agent solution, adding resin and an amino organic lithium compound, uniformly mixing, adding a hydrogen peroxide oxidizing agent, reacting, filtering, and activating at high temperature to obtain lithium-doped porous carbon; the preparation method comprises the following steps: adding lithium-doped porous carbon into an organic solvent, then adding graphite and an organic aluminum-based compound, uniformly dispersing, dropwise adding an amino solution, carrying out chemical reaction at the temperature of 50-120 DEG C, filtering, and carrying out vacuum drying and high-temperature carbonization on obtained filter residues to obtain the lithium-doped porous carbon composite material. The cycle performance and the storage performance of the graphite can be improved.

The invention discloses a fast-charging low-temperature graphite composite material, a preparation method and application thereof, the composite material is of a core-shell structure, the core is porous graphite and a carbon nanotube doped with the porous graphite, and the shell is composed of a lithium supplement agent and a lithium sulfonate complex of the lithium supplement agent. The preparation method comprises the following steps: soaking porous graphite in a conductive polymer solution, adding a catalyst, a cross-linking agent and an oxidizing agent, carrying out oxidative polymerization and carbonization to obtain catalyst-doped porous graphite, and introducing carbon source gas through a vapor deposition method to obtain carbon nanotube-doped porous graphite; and adding the obtained material into a lithium sulfonate solution, adding a lithium supplement agent, uniformly mixing, and carrying out spray drying to obtain the graphite composite material. According to the obtained material, the electronic conductivity of the material is improved by using the carbon nanotubes grown on the inner core, and the lithium sulfonate coated on the outer shell has relatively strong solvation capability, so that the transmission rate of lithium ions is improved, and the rate capability is improved; meanwhile, the lithium supplement agent releases lithium ions in the charging and discharging process, the first efficiency is improved, and the low-temperature and fast-charging performance is improved.

The invention relates to a graphite composite material, a preparation method thereof, a negative electrode and a battery, the graphite composite material comprises a graphite inner core and a coating layer coating the graphite inner core, and the coating layer comprises porous carbon coating the graphite inner core and elemental phosphorus deposited in and on the surface of the porous carbon. The performance of a conventional graphite negative electrode is reduced during high-rate charging and discharging, and the compatibility with an electrolyte is limited; according to the invention, the surface of the graphite core is firstly coated with the porous carbon, and then the phosphorus is deposited on the surface and in the pores of the porous carbon coating layer, so that the defects in the prior art are overcome, and the cycling stability and rate capability of the graphite negative electrode are improved.

The invention belongs to the related technical field of carbon materials and batteries, and particularly relates to a preparation method of a carbon-coated graphite composite material, the carbon-coated graphite composite material and a battery negative electrode. A preparation method of a carbon-coated graphite composite material comprises the following steps: mixing an alkaline mixed solution containing a graphite material, a main carbon source for coating, a synergistic carbon source for coating and an auxiliary agent to obtain a dispersion liquid; performing drying and coking treatment on the dispersion liquid under a preset condition to form a carbon-coated graphite precursor; carrying out carbonization treatment on the carbon-coated graphite precursor under a protective gas environment condition to obtain a carbon-coated graphite composite material; the main carbon source for coating comprises saccharides; the synergistic carbon source for coating comprises a compound containing non-carbon heteroatoms; and the auxiliary agent comprises a surfactant, can be in synergistic effect with the synergistic carbon source for coating, and can fully disperse the alkaline mixed solution to obtain a uniformly distributed dispersion solution.

The invention discloses a tantalum carbide / graphite composite material and a preparation method thereof, and relates to the field of graphite / coating composite materials. The tantalum carbide / graphite composite material comprises a graphite matrix, a transition layer and a tantalum carbide coating, wherein the transition layer is connected with the graphite matrix and the tantalum carbide coating; the transition layer comprises graphite and tantalum carbide, pores of the graphite are filled with the tantalum carbide, and in the transition layer, the porosity of the graphite is gradually reduced in the direction from the tantalum carbide coating to the graphite matrix, the content of the tantalum carbide is gradually reduced, and the porosity of the tantalum carbide is gradually reduced in the direction from the tantalum carbide coating to the graphite matrix. At least part of tantalum carbide in the transition layer extends from pores of graphite to the tantalum carbide coating and is connected with the tantalum carbide coating. Therefore, a strong binding force is formed between the coating and the matrix, and the service life of the composite material can be prolonged; the transition layer can slow down mutation of the thermal expansion coefficient between the graphite matrix and the tantalum carbide coating, and stress release caused by thermal shock is promoted.

The invention discloses a preparation method of a nano-diamond / graphite composite film electrode with high hydrogen evolution potential and low background current, which comprises the following steps: firstly, preparing the nano-diamond / graphite composite film electrode through hot filament chemical vapor deposition, and then carrying out electrochemical anodic oxidation treatment on the composite film electrode. And finally obtaining the nano-diamond / graphite composite film electrode with high hydrogen evolution potential and low background current. According to the method disclosed by the invention, the content of diamond in the composite film electrode can be increased, and the oxygen element is grafted on the surface of the nano-diamond / graphite composite film electrode, so that the background current of the nano-diamond / graphite composite film electrode is reduced while the hydrogen evolution potential of the nano-diamond / graphite composite film electrode is improved; and a new thought and scheme are provided for design and preparation of the novel nano-diamond film-based composite electrode.

The invention belongs to the technical field of micro-nano composite materials, and particularly relates to a preparation method and application of a multi-metal sulfide-expanded graphite composite material. The preparation method of the multi-metal sulfide-expanded graphite composite material comprises the following steps: recovering graphite negative electrodes of waste lithium ion batteries, constructing cross-linked porous three-dimensional expanded graphite through a controllable expansion strategy, uniformly loading multi-metal sulfide nanoparticles on the surface of the expanded graphite by adopting a hydrothermal method, and carrying out heat treatment to obtain the composite material. The three-dimensional grid structure of the expanded graphite not only provides uniformly dispersed anchoring points for the polymetallic sulfide nanoparticles, but also constructs a continuous conductive network. According to the heterogeneous interface engineering, the charge transfer resistance is reduced, and agglomeration and volume expansion of active substances in circulation are inhibited through the topological confinement effect. The polymetallic sulfide-expanded graphite composite material prepared by the method has good structural stability and electrical conductivity, and the cycling stability of a battery can be remarkably improved when the polymetallic sulfide-expanded graphite composite material is used as a battery material.

The invention relates to the technical field of all-vanadium redox flow battery electrodes, and discloses a preparation method of an iron-tungsten loaded graphite felt for a vanadium redox flow battery, which comprises the following steps: dissolving a tungstic acid compound, ferrite and a surfactant in water to prepare an electrodeposition solution; the preparation method comprises the following steps: immersing a graphite felt in an electro-deposition liquid, carrying out vacuum standing, taking out the graphite felt as a working electrode, carrying out electrochemical deposition, cleaning and drying, immersing the obtained metal-loaded graphite felt in an aqueous solution containing benzene peroxide series and phenylenediamine substances, carrying out hydrothermal treatment, cleaning and drying, and carrying out high-temperature treatment on the obtained precursor graphite felt to obtain the metal-loaded graphite composite material. And obtaining the iron-tungsten loaded graphite felt for the vanadium battery. By loading iron and tungsten on the graphite felt, the catalytic activity site and conductivity of the graphite felt can be effectively improved, the benzene peroxide series can partially oxidize tungsten, generated carboxylic acid and phenylenediamine substances form a condensate, and the catalytic activity and stability of the graphite felt fiber are further improved.

The invention discloses a SiOX / microcrystalline graphite negative electrode material and a preparation method and application thereof. Relates to the technical field of lithium battery cathode materials. The preparation method comprises the following steps: by taking microcrystalline graphite as a base material, growing nano silicon oxide particles in situ on the surface of the microcrystalline graphite and in gaps of sheet layers by adopting a hydrothermal reaction method to form a SiOX / microcrystalline graphite composite material, and coating the surface of the SiOX / microcrystalline graphite composite material with a carbon coating layer with a complete carbon layer structure, and finally, the SiOX / microcrystalline graphite negative electrode material with the core-shell structure is formed. By adopting the technical scheme, the stress effect caused by silicon volume expansion in the charging and discharging process is counteracted and inhibited by utilizing the disordered layer structure characteristic that the structure orientation of fine scales of the microcrystalline graphite is different; meanwhile, the nano SiOX particles are filled in the gaps of the microcrystalline graphite flake layer, and the fine flake graphite constructs a three-dimensional conductive network structure, so that the problem of poor conductivity of the SiOX particles is solved.

The invention belongs to the field of lithium ion battery materials, and provides a composite coating coated graphite composite negative electrode material and a preparation method and application thereof, and the preparation method comprises the following steps: (1) preparing a niobium pentoxide coated graphite precursor material; and (2) coating the niobium pentoxide coated graphite precursor material with a titanium dioxide coating by adopting a sol-gel method, and calcining to obtain the niobium pentoxide coated graphite composite material. According to the prepared composite coating coated graphite negative electrode material, the niobium pentoxide coating can reduce the interface impedance, and the titanium dioxide coating can ensure the stability of the structure. Therefore, the negative electrode not only has excellent rate capability, but also keeps excellent cycling stability, and the preparation method is simple and convenient.