12131results about "Carbon preparation/purification" patented technology

A hard carbon negative electrode material as well as a preparation method therefor and a use thereof. The hard carbon negative electrode material comprises a hard carbon base material, heteroatoms and metal monoatoms, wherein the metal monoatoms are doped into the hard carbon base material by means of the heteroatoms, the heteroatoms comprise at least one of N, P or S, and the metal monoatoms are metal monoatoms that can undergo an alloying reaction with sodium. The metal monoatoms are doped into the hard carbon base material by means of covalent (chemical bond) interactions with other heteroatoms, so that the doping of single atoms is achieved, thereby improving the overall capacity and rate capability of a sodium ion battery at normal temperature, and ensuring the capacity retention rate of the sodium ion battery under a low temperature condition.

A method of manufacturing a carbon nanostructure, such as a carbon foam material, is disclosed. The method comprises the steps of: (a) using a first laser beam to irradiate an encapsulated or sub-surface region of a carbon pre-cursor material below a surface of the material, to create carbon foam in that sub-surface region, and a disorganised, amorphous non-graphene material above the carbon foam, and then (b) using a second laser beam to remove or ablate the disorganised, amorphous non-graphene material sitting above the carbon foam, to expose at least some of the carbon foam. The resultant carbon foam material shows a significant D peak; the 2D peak is significantly less than the G peak; and the peak D: peak G ratio is significantly above zero. In appearance and Raman signature, it appears similar to a carbon nano-onion material. It can be used in biosensors, supercapacitors and pseudo-capacitors.

The invention relates to the technical field of lithium ion battery materials, in particular to a chemical liquid phase deposition silicon-carbon negative electrode material and a preparation method and application thereof.The silicon-carbon negative electrode material comprises a porous carbon skeleton and nanometer silicon particles deposited on the surface and in pore channels of the porous carbon skeleton; the carbon source coating layer is used for coating the porous carbon skeleton and the nano silicon particles. The interior of the composite structure of the silicon-carbon negative electrode material is nanometer silicon particles deposited on the surface and in pore channels of a porous carbon skeleton, and the outer layer is a coating layer; porous carbon is used as a continuous and stable carbon skeleton to effectively relieve volume expansion and particle fragmentation of the silicon-based material, and the outermost coating layer improves the structural stability and conductivity of the composite material, so that the electrochemical cycle stability is improved; according to the structure of the silicon-carbon negative electrode material, the advantages of an embedded structure and a shell-core structure are combined, a stable carbon skeleton is provided for the silicon-carbon negative electrode material, a limited expansion space is provided for silicon particles, crushing is prevented, and the cycling stability of the negative electrode material is greatly improved.

The invention provides a modified three-dimensional porous carbon-based silicon-carbon negative electrode material and a preparation method thereof, and belongs to the technical field of lithium ion battery negative electrode materials. The preparation method comprises the following steps: mixing an organic carbon source and a conductive agent in a solution, and sequentially drying, curing and carbonizing the obtained mixture under an inert gas condition to obtain a modified carbon precursor; carrying out activating treatment on the modified carbon precursor under an inert gas condition to obtain a modified three-dimensional porous carbon skeleton; under the condition of protective gas, introducing silane gas into the modified three-dimensional porous carbon skeleton, and carrying out vapor deposition to obtain a silicon / modified three-dimensional porous composite material; and under the condition of protective gas, introducing carbon source gas into the silicon / modified three-dimensional porous composite material, and carrying out vapor deposition to obtain the modified three-dimensional porous carbon-based silicon-carbon negative electrode material. The prepared modified three-dimensional porous carbon-based silicon-carbon negative electrode material is low in expansion rate, good in cycle performance and excellent in conductivity.

The invention discloses a silicon-carbon negative electrode material and a preparation method and application thereof.The silicon-carbon negative electrode material comprises a porous carbon substrate, a silicon element distributed in pore channels of the porous carbon substrate and carbon coating the outer surfaces of the porous carbon substrate and the silicon element, the porous carbon substrate is prepared after two times of activating treatment, and the silicon element is prepared after two times of activating treatment. The porous carbon has dendritic pore channels and meets at least one of the following conditions: a, the volume ratio of micropores is 10-30%; b, the volume ratio of mesopores is 60-90%; c, the volume ratio of macropores is 0-10%; d, the specific surface area is not less than 200m < 2 > / g; e, the pore volume is not less than 0.4 cm < 3 > / g; and f, the average particle size D50 is 1-20 [mu] m. By activating the porous carbon substrate, more buffer spaces can be provided for volume expansion of nano silicon particles from the angle of substrate preparation, and the cycling stability of the silicon-carbon negative electrode material is remarkably improved.

The invention provides a negative electrode material, a preparation method thereof and a battery. The negative electrode material comprises graphite and a carbon layer located on at least part of the surface of the graphite; the particle surface and the particle tangent plane of the negative electrode material are respectively tested by adopting a Raman spectrum, the ratio of the peak area of a characteristic peak D in the range of 1300 cm <-1 > to 1350 cm <-1 > to the peak area of a characteristic peak G in the range of 1500 cm <-1 > to 1580 cm <-1 > is ID / IG, the ID / IG ratio of the particle surface of the negative electrode material is A, the ID / IG ratio of the particle tangent plane of the negative electrode material is B, and 1.22 < A-B < = 2.10. The particle surface of the negative electrode material is tested through an atomic force microscope, a # imgabs0 # test area is randomly selected on the particle surface of the negative electrode material, the arithmetic mean value of the absolute value of the height deviation relative to the reference surface in the test area is S nm, and S is larger than or equal to 15 nm and smaller than or equal to 60 nm. The negative electrode material provided by the invention can comprehensively improve lithium ion transmission kinetics, first coulombic efficiency and cycle performance.

A method of manufacturing a carbon nanostructure, such as a carbon foam material, is disclosed. The method comprises the steps of: (a) using a first laser beam to irradiate an encapsulated or sub-surface region of a carbon pre-cursor material below a surface of the material, to create carbon foam in that sub-surface region, and a disorganised, amorphous non-graphene material above the carbon foam, and then (b) using a second laser beam to remove or ablate the disorganised, amorphous non-graphene material sitting above the carbon foam, to expose at least some of the carbon foam. The resultant carbon foam material shows a significant D peak; the 2D peak is significantly less than the G peak; and the peak D: peak G ratio is significantly above zero. In appearance and Raman signature, it appears similar to a carbon nano-onion material. It can be used in biosensors, supercapacitors and pseudo-capacitors.

The invention discloses a preparation method of a high-compaction-density lithium iron phosphate material, through grading of large and small particle lithium iron phosphate, optimization of a sintering process and reasonable selection of a carbon source and a titanium dopant, the compaction density and the electrochemical performance of the material are remarkably improved, and the preparation method specifically comprises the following steps: mixing iron phosphate, lithium carbonate, the carbon source and auxiliary materials; the preparation method comprises the following steps: carrying out coarse grinding and fine grinding, respectively preparing large-particle lithium iron phosphate and small-particle lithium iron phosphate (a material A and a material B) by adopting spray drying and high-temperature calcination processes, mixing the material A and the material B according to a ratio, adding auxiliary materials, grinding, further carrying out spray drying, calcining and crushing to obtain a final lithium iron phosphate product, and the maximum compaction density of the prepared material can reach 2.712 g / cm < 3 >. According to the present invention, the maximum 1C discharge specific capacity can achieve 140.5 mAh / g, the maximum 1C 3.2 V discharge platform retention rate is 91.4%, and the prepared lithium ion battery negative electrode material has characteristics of excellent conductivity, high discharge capacity and good cycle stability, and is suitable for power batteries and energy storage batteries.

A method of manufacturing a carbon nanostructure, such as a carbon foam material, is disclosed. The method comprises the steps of: (a) using a first laser beam to irradiate an encapsulated or sub-surface region of a carbon pre-cursor material below a surface of the material, to create carbon foam in that sub-surface region, and a disorganised, amorphous non-graphene material above the carbon foam, and then (b) using a second laser beam to remove or ablate the disorganised, amorphous non-graphene material sitting above the carbon foam, to expose at least some of the carbon foam. The resultant carbon foam material shows a significant D peak; the 2D peak is significantly less than the G peak; and the peak D: peak G ratio is significantly above zero. In appearance and Raman signature, it appears similar to a carbon nano-onion material. It can be used in biosensors, supercapacitors and pseudo-capacitors.

The invention discloses a wide-temperature-range high-rate lithium iron phosphate positive electrode material, a preparation method and a lithium ion battery, and the preparation method comprises the following steps: S1, uniformly mixing an iron source, a phosphorus source, a lithium source, a first carbon source, a transition metal-containing dopant and a dispersant, and carrying out first grinding; s2, performing spray drying on the slurry subjected to primary grinding to obtain a first precursor; s3, sintering the first precursor for the first time under the protection of an inert gas atmosphere; s4, mixing a material obtained after primary sintering, a second carbon source and a dispersing agent, and then performing secondary grinding; s5, performing spray drying on the slurry obtained by secondary grinding to obtain a second precursor; and S6, sintering the second precursor for the second time under the protection of the inert gas atmosphere to obtain the lithium iron phosphate positive electrode material. After the positive electrode material provided by the invention is assembled into a battery, the side reaction of lithium iron phosphate and electrolyte can be effectively reduced, and the positive electrode material not only has low-temperature high-rate performance, but also has excellent high-temperature cycle performance.

The invention discloses a composite positive electrode material and a preparation method thereof, a positive plate and a lithium ion battery. The composite positive electrode material comprises lithium iron phosphate and a carbon coating layer coating the surface of the lithium iron phosphate, wherein the integral intensity ratio ID / IG of a D peak to a G peak of the carbon coating layer in a Raman spectrum is 0.2-0.9, and the resistivity of the composite positive electrode material is 0.1-10 omega.cm. According to the preparation method, the graphitization degree of the carbon coating layer is controlled within a proper range (ID / IG is 0.2-0.9), so that good conductivity is ensured, and structural instability caused by excessive graphitization is avoided. The moderate graphitization degree is beneficial to formation of an ordered carbon layer structure, provides more electron transport channels and reduces the potential barrier of electron migration, so that the conductivity of the composite material is greatly improved, and the resistivity is reduced to an excellent level of 0.1-10 omega.cm.

The invention provides a silicon-carbon negative electrode material fluidized bed reaction system, and relates to the technical field of fluidized bed equipment. Comprising a raw material conveying system, a fluidized bed reactor, a high-temperature discharging system, a process gas inlet pipeline and a protection system. According to the scheme, the uniformity and safety of the fluidization reaction can be improved, and the working efficiency can be improved.

The invention provides a high-rate and high-first-effect biomass hard carbon composite negative electrode material and a preparation method and application thereof, the hard carbon composite negative electrode material has a core-shell structure, the core-shell structure comprises a core, an inner shell and an outer shell, the core comprises biomass hard carbon containing P and graphite microcrystals, the inner shell comprises graphene, and the outer shell comprises a carbon nanotube. According to the invention, the surface of the biomass hard carbon is coated with the graphene layer, the carbon nanotubes grow on the surface of the graphene in situ, and transition metal synergistically induces the hard carbon to be arranged and grow along the graphene layer in a high-temperature carbonization process, so that the graphene coating layer is tightly coated, and the cycle performance of the material is improved; transition metal ions catalyze graphitization to generate a more regular and ordered graphite-like layer microcrystalline structure coating layer, so that the defects of graphene and carbon nanotubes are reduced, and the first coulombic efficiency is improved; in addition, the ion transmission capability is improved by phosphorus doping, the electron transmission capability is improved by graphite microcrystals generated by catalysis in hard carbon, and the rate capability is ensured by synergistic improvement of ion transmission and electron transmission.

The invention provides a silicon-carbon negative electrode material and a preparation method thereof. The preparation method comprises the following steps: a) mixing a phenol monomer, an aldehyde solution, ammonia water and water, dropwise adding a boric acid solution for reaction, and curing to obtain boron-containing phenolic resin; b) carbonizing the boron-containing phenolic resin obtained in the step a), mixing with alkali, and activating to obtain boron-doped porous carbon; and c) carrying out silicon deposition on the boron-doped porous carbon obtained in the step b) by adopting a gaseous silicon source, carrying out carbon coating by adopting a gaseous carbon source, and cooling to obtain the silicon-carbon negative electrode material. Compared with the prior art, the preparation method provided by the invention has the advantages that a conductive network can be formed by doping the boron element, the electron concentration can be improved, the electron transfer rate is favorably improved, the conductivity of the material is effectively enhanced, and the rate capability of the negative electrode material is effectively improved; meanwhile, the residual carbon rate in the porous carbon preparation process can be greatly increased, and the cost of the whole silicon-carbon negative electrode material is effectively reduced.

The present invention provides a negative electrode active material which has negative electrode active material particles, the negative electrode active material being characterized in that: the negative electrode active material particles each include a porous carbon structure; amorphous low valence nano silicon oxide is dispersed inside the porous carbon structure; the low valence nano silicon oxide includes the states where SiOx:x < 1.0 is satisfied; and the low valence nano silicon oxide has an average particle diameter of 50 nm or less as determined by image processing of a cross-sectional TEM image thereof. As a result, a negative electrode active material which is capable of increasing the capacity while maintaining the battery characteristics is provided.

The invention relates to a preparation method and application of a manganese ion doped modified ferric sodium pyrophosphate positive electrode material, and belongs to the technical field of sodium ion battery positive electrodes. The preparation method comprises the following steps: adding a sodium source, a phosphorus source and a carbon source into ethanol, uniformly mixing to form a mixed solution, sequentially adding an iron source and a manganese source into the mixed solution, uniformly mixing to form slurry, and drying the slurry to obtain precursor powder; calcining in a protective atmosphere to obtain a manganese-doped carbon-coated ferric pyrophosphate sodium material; the calcining conditions are as follows: heating to the temperature of 300-350 DEG C at the heating rate of 2-3 DEG C / min, carrying out first-stage constant-temperature calcination for 2-3 hours, heating to the temperature of 500-550 DEG C at the heating rate of 5-8 DEG C / min, and carrying out second-stage constant-temperature calcination for 10-12 hours. By doping the manganese ions, the electronic conductivity and the ion diffusivity of the ferric sodium phosphate pyrophosphate composite material are improved, so that the discharge capacity of the ferric sodium phosphate pyrophosphate composite material at high rate is improved, and the battery has relatively high cycle stability.

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 provides a lithium ion secondary battery, a battery device, a power utilization device, a preparation method of a positive electrode active material and a preparation method of a positive electrode plate. The lithium ion secondary battery comprises a positive pole piece, a negative pole piece and an electrolyte, the positive pole piece comprises a positive current collector and a positive film layer arranged on at least one side of the positive current collector, and the positive film layer comprises a positive active material; the positive electrode active material comprises lithium-containing transition metal phosphate particles, at least part of the surfaces of the lithium-containing transition metal phosphate particles are provided with carbon coating materials, and in the tangent plane of the positive electrode film layer in the thickness direction of the pole piece, DA90 of the particles is 1400 nm to 2100 nm; the particle size concentration ratio (DA90-DA10) / DA50 is 1.855-2.375, and DA90, DA50 and DA10 refer to the particle sizes of the corresponding particles when the cumulative area distribution of the particles reaches 90%, 50% and 10% in an area cumulative distribution curve of the particles.

The invention provides a lithium-rich lithium ferrite material and a preparation method and application thereof, the lithium-rich lithium ferrite material comprises a core layer and a carbon coating layer, the core layer is doped lithium-rich lithium ferrite, the chemical formula of the doped lithium-rich lithium ferrite is Li < 5 > Fe < 1-x > Al < x > O < 4 >, and x is 0.003-0.030. The lithium-rich lithium ferrite material is high in structural stability and excellent in conductivity; as a lithium supplement additive of a positive electrode active material, the composite material can improve electrochemical performance such as high-temperature storage performance and normal-temperature cycle performance of a lithium ion battery.

The invention relates to a hard carbon negative electrode material, a preparation method of the hard carbon negative electrode material and a sodium ion battery. The closed pore volume Vcp of the hard carbon negative electrode material is more than 0.01 cm < 3 > / g and less than 0.5 cm < 3 > / g; the condition that Vcp is equal to 1 / rho true-1 / (2.26 * 0.3354 / d002act) is met; wherein rho true is the true density of the hard carbon negative electrode material, d002act is the interlayer spacing of X-ray diffraction 002 crystal lattices, and the true density of the hard carbon negative electrode material is 0.5 g / cm < 3 > < rho true < 2.26 g / cm < 3 >. By controlling the temperature and the pressure, the true density of the negative electrode material is directly controlled, and the closed pore structure proportion of the negative electrode material is indirectly controlled, so that the negative electrode material has relatively high reversible specific capacity and first coulombic efficiency, and the assembled sodium ion battery has relatively high energy density and excellent rate capability.

The invention discloses a transition metal nitride and amorphous carbon composite coated and modified lithium manganese iron phosphate composite material as well as a preparation method and application thereof, and belongs to the technical field of lithium ion batteries. The vanadium nitride / amorphous carbon is adopted to perform composite coating modification on the lithium manganese iron phosphate material, so that the composite positive electrode material is more stable in structure. The use of vanadium nitride reduces the coating amount of carbon, and avoids the problems of coating layer thickening caused by high carbon content and Li < + > diffusion hindering caused by reduction of tap density of active substances. Vanadium nitride not only has good conductivity, but also has good Li < + > conductivity transmission performance, Li < + > de-intercalation can be rapidly achieved, the conductivity of the material is improved, meanwhile, a Li < + > diffusion channel on the surface of the positive electrode material is further dredged and increased, and the capacity loss of the modified material is reduced.

The invention provides a lithium iron manganese phosphate positive electrode material and a preparation method and application thereof, the lithium iron manganese phosphate positive electrode material comprises a doped type iron manganese phosphate inner core and a coating layer coating the surface of the doped type iron manganese phosphate inner core, and the coating layer is a lithium-containing carbon layer; the doped iron manganese phosphate inner core comprises doped ions, and in the particles of the doped iron manganese phosphate inner core from inside to outside, the content gradient of manganese ions and iron ions is reduced, and the content gradient of the doped ions is increased. According to the lithium manganese iron phosphate positive electrode material with the structure, a series of problems caused by poor phase structure stability, poor conductivity and Jahn-Teller effect and manganese dissolution of the material in the lithium manganese iron phosphate positive electrode material can be effectively improved; further, the conductivity of the lithium manganese iron phosphate positive electrode material and the comprehensive performance of gram volume, cycling stability and the like when the lithium manganese iron phosphate positive electrode material is applied to a battery are improved.

The invention discloses a lithium iron phosphate positive electrode material and a preparation method thereof, a positive electrode plate and a lithium battery, and relates to the technical field of lithium batteries. The agglomeration strength of the lithium iron phosphate positive electrode material provided by the invention is in a proper range, the lithium iron phosphate positive electrode material is easy to disperse in a slurry preparation process, the prepared positive electrode slurry has no obvious granular sensation and good fluidity, and the surface density of a positive electrode piece obtained by coating is uniform, so that the resistivity of the pole piece is relatively low.

The invention discloses a preparation method of porous carbon, the porous carbon, a negative electrode material and a secondary battery, the preparation method of the porous carbon comprises the following steps: granulation: drying and granulating a phenolic resin microsphere suspension to obtain powder; nano carbon nanotubes are dispersed in the phenolic resin microspheres; and carbonization: sequentially carrying out secondary curing, pre-oxidation and carbonization on the powder to obtain the porous carbon. According to the preparation method, the porous carbon is prepared by adopting the nanoscale carbon nanotubes, firstly, the conductivity of the porous carbon is favorably improved due to the good conductivity of the carbon nanotubes, and meanwhile, the nanoscale carbon nanotubes are utilized, so that the carbon nanotubes can be more sufficiently dispersed, and the effect of improving the conductivity of the porous carbon by the carbon nanotubes is more favorably exerted; secondly, the tin or germanium element doped into the negative electrode material assists lithium ion deintercalation by reducing lithium ion transition energy barriers, so that the first effect is improved.

The invention discloses an asphalt-based hard carbon material as well as a pre-oxidation preparation method and application thereof. Belongs to the technical field of asphalt-based hard carbon materials. The pre-oxidation preparation method comprises the following steps: carrying out primary pre-oxidation treatment on asphalt at 250-400 DEG C in air flow of 50-500mL / min; crushing the obtained primary pre-oxidized asphalt, and then carrying out secondary pre-oxidation treatment at 250-400 DEG C in air flow of 50-500mL / min to obtain secondary pre-oxidized asphalt; and carrying out carbonization treatment on the secondary pre-oxidized asphalt. According to the method, the asphalt can be kept in a solid-phase state to be subjected to efficient and thorough oxidation cross-linking reaction, the production cost is reduced, the obtained asphalt-based hard carbon material has high first coulombic efficiency and high capacity, and powerful support is provided for commercial application of sodium-ion battery negative electrode materials and rapid development of an energy storage technology.

The invention provides a lithium-supplementing positive electrode material and a preparation method and application thereof, the lithium-supplementing positive electrode material comprises an active material core and a coating layer coating the surface of the active material core, and the coating layer comprises lithium-supplementing particles and carbon; the active material inner core comprises one or more of LixFeyPO4 and LiFezMn1-zPO4, x is more than or equal to 0.9 and less than or equal to 1.1, y is more than or equal to 0.9 and less than or equal to 1.1, and 0 lt; zlt, zlt; 1; the lithium supplement particles comprise LiaMbOc, M is selected from one or more of Fe, Mn, Ni, Zr, Co, Cr and Cu, a is greater than 0 and less than or equal to 6, b is greater than 0 and less than or equal to 3, and c is greater than 0 and less than or equal to 5. The lithium-supplementing positive electrode material can effectively reduce the risk of a gel phenomenon of positive electrode active slurry, can improve the electron conduction capability and the ion conduction capability of the positive electrode active slurry, can effectively solve the problem of gas production in the later use process of a battery, and further improves the rate capability and the cycle performance of the battery.

The invention discloses a zinc-iodine battery positive electrode material based on corn straw shell derived porous carbon and a preparation method of the zinc-iodine battery positive electrode material. According to the material, corn straw shells serve as the sole carbon source, an indigenous nitrogen-doped biomass charcoal carrier with a hierarchical pore structure is prepared through pre-carbonization and KOH activation processes, and the material is characterized in that the specific surface area is larger than or equal to 1500 m < 2 > / g, and the micropore proportion is larger than 90%. The iodine is loaded on the carrier (the iodine content is greater than or equal to 45wt%) through a vacuum sublimation method to form the indigenous nitrogen-doped biomass charcoal / iodine composite material. According to the positive electrode material, through the synergistic effect of physical confinement and pyridine nitrogen chemical adsorption, the multi-iodide shuttle effect is effectively inhibited, so that the capacity retention rate of the zinc-iodine battery is greater than or equal to 93% after 40000 cycles under the current density of 2A g <-1 >, and the capacity retention rate is greater than 45% under the rate of 10A / g. The method has double benefits of agricultural waste resource utilization and high-performance energy storage device development.

The invention belongs to the technical field of sodium ion battery negative electrode materials, and particularly relates to an amylocellulose composite hard carbon material as well as a preparation method and application thereof. Pre-oxidation and pre-carbonization are carried out step by step, the starch cellulose composite hard carbon material is prepared through low-temperature pre-oxidation, a ball milling method, low-temperature pre-carbonization and a high-temperature pyrolysis method in sequence, the obtained starch cellulose composite hard carbon material is used for preparing the negative electrode of the sodium-ion battery, and then the sodium-ion battery is further constructed. An electrochemical performance test result shows that the obtained sodium ion battery has excellent first-circle coulombic efficiency, cycle performance and rate capability; moreover, the preparation method of the starch cellulose composite hard carbon material is simple to operate, can perform a pre-oxidation process in an air atmosphere, does not need additional oxidation treatment, is environment-friendly, can prevent the starch cellulose composite material from melting and foaming in high-temperature pyrolysis, improves the cycling stability of the material, and is suitable for industrial production.

The invention provides a lithium ion battery silicon-based negative electrode material as well as a preparation method and application thereof, and relates to the technical field of lithium ion battery negative electrode materials. The preparation method provided by the invention comprises the following steps: stirring and mixing a surface-activated silicon-carbon matrix in an organic solution in which a polymer is dissolved, separating and drying to obtain a composite matrix; mixing the composite matrix in an inorganic lithium salt solution, evaporating the solvent to dryness, and carbonizing at 300-400 DEG C to obtain a composite intermediate; reducing the composite intermediate in a hydrogen atmosphere at 200-300 DEG C to obtain a negative electrode intermediate; and stirring and mixing the negative electrode intermediate in the organic solution, separating and drying, and carbonizing at 700-800 DEG C to obtain the silicon-based negative electrode material of the lithium ion battery. The prepared negative electrode material has relatively high structural stability, and after the negative electrode material is applied to the lithium ion battery, the capacity performance and the cycling stability of the lithium ion battery can be remarkably 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.