2735results about "Graphene" patented technology

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.

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 positive electrode material for a zinc-bromine flow battery and a preparation method and application thereof, and belongs to the technical field of zinc-bromine flow batteries, the preparation method comprises the following steps: crushing and sieving an active carbon source, adding the active carbon source into a graphene oxide aqueous dispersion, stirring, centrifuging, removing supernate, drying, mixing with an activating agent, and activating in an inert atmosphere; washing to be neutral, drying and sieving to obtain a graphene / activated carbon composite material; and attaching the graphene / activated carbon composite material to a carbon-plastic bipolar plate to obtain the positive electrode material for the zinc-bromine flow battery. A graphene / activated carbon composite system is combined with a high-conductivity network, graded holes and surface functional groups, so that the reaction kinetics bottleneck of a traditional carbon material Br2 is broken through.

The invention discloses a nano-copper modified reduced graphene oxide powder preparation method, which comprises: S1, uniformly mixing a reduced graphene oxide dispersion liquid and a copper chloride solution to obtain a mixed liquid A; s2, reducing the mixed solution A by adopting a reducing agent to obtain a mixed solution B; s3, adjusting the pH value of the mixed solution B to 8-9 to obtain a mixed solution C; s4, titrating the mixed solution C with an alkaline solution until the mixed solution C is red, and standing and filtering to obtain a precipitate D; s5, washing the precipitate D until the pH value of supernatant liquid is neutral, and drying to obtain a precipitate E; and S6, sintering the precipitate E in an inert atmosphere to obtain the nano-copper modified reduced graphene oxide powder. The invention further discloses the nano-copper modified reduced graphene oxide powder, the high-strength and high-conductivity graphene copper plating-aluminum matrix composite and a preparation method of the high-strength and high-conductivity graphene copper plating-aluminum matrix composite.

The invention provides a method for preparing aerogel by using high-carbon components in coal gas fine slag, which is characterized in that the high-carbon components with ash content lower than 30% in the coal gas fine slag are separated into light carbon and heavy carbon through an isodensity gradient centrifugation or ultrasonic separation technology. The light carbon is subjected to acid leaching impurity removal to obtain a carbon precursor, and then carbon aerogel is synthesized through a chemical activation method; the preparation method comprises the following steps: carrying out oxidation stripping on heavy carbon by using strong acid to obtain graphene oxide, then carrying out alkali activation for reduction, and finally carrying out acid pickling to obtain the graphene aerogel. The composition structural characteristics of the coal gasification fine slag residual carbon are fully utilized, and the preparation of the high-performance aerogel is realized through refined separation and treatment. According to the method, the resource utilization rate of the coal gasification fine slag can be increased, and a new path is provided for preparation of a high-added-value carbon material.

According to the high-compression-resilience thermal interface material and the preparation method thereof, high-thermal-conductivity fibers and elastic macromolecules are introduced between graphene sheets which are arranged in an oriented mode, and the graphene sheets form a bent structure on the surfaces of the fibers under the action of pressure; graphene and high-heat-conduction fibers are firmly combined through elastic macromolecules, the compression resilience capacity is improved, physical crosslinking is formed between bent graphene sheets through pi-pi conjugation, and therefore the material with a heat conduction framework and an elastic microstructure is constructed. And then cutting along the direction perpendicular to the graphene sheets to obtain the interface material containing the bent graphene sheets and the high-thermal-conductivity fibers, so that the material has high vertical thermal conductivity, high horizontal thermal conductivity and high compression ratio.

Methods for stabilizing laser-induced graphene (LIG) through composite formation and compositions thereof. Using infiltration methods and / or lamination methods, LIG composites (LIGCs) with physical properties can be engineered on various substrate materials. The physical properties include surface properties, such as superhydrophobicity and antibiofouling; the LIGCs are also useful in antibacterial applications, Joule-heating applications, and as resistive memory device substrates. Further, methods for fabricating and using LIG for flexible and embeddable gas sensors.

The invention relates to the field of treatment and resource utilization of high-carbon-content materials, in particular to a method for preparing graphene at high temperature through electric pulses. The method comprises the following steps: mixing a non-graphitized carbon material and a conductive carbon material to obtain a mixture; pulse current is applied to the mixture, so that the temperature of the mixture is increased to 2000-3000 DEG C, and the mixture subjected to electric heat treatment is obtained; and carrying out cooling treatment on the mixture subjected to the electric heat treatment to obtain the graphene, wherein the carbon content in the non-graphitized carbon material is greater than or equal to 50wt%; the heating rate is 103-104 DEG C / s. According to the method, the carbon atom conversion rate is remarkably increased, the graphene preparation cost is greatly reduced, and meanwhile, the environmental problem caused by a traditional incineration or landfill mode is solved through high value-added utilization of the high-carbon-content waste. Compared with a traditional graphene preparation method, low-cost, high-quality and green preparation of graphene is achieved, the method is suitable for high-valued treatment of various high polymer materials and industrial waste, and a new technical path is provided for large-scale preparation and application of graphene.

The invention discloses a calcining carbon removal-supercritical expansion stripping method for regenerating graphene from graphite of a waste lithium battery, and belongs to the field of lithium battery recovery and nano material preparation. Comprising the following steps: treating the waste lithium battery to obtain waste lithium battery positive and negative electrode mixed powder, and then roasting to obtain battery powder; leaching the battery powder in a nitric acid solution to obtain purified graphite slag; the method comprises the following steps: mixing graphite slag with supercritical gas fluid, treating, quickly releasing pressure to normal pressure, and separating to obtain graphene. According to the method, on the basis of interlayer structure characteristics of the waste graphite negative electrode, organic matters and amorphous carbon are removed through multi-stage calcination, a supercritical N2 / CO2 mixed fluid permeation and pressure relief expansion synergistic stripping technology is combined, and low-damage dissociation is achieved through graphite microcracks. According to the method, physical stripping and liquid nitrogen shock cooling strengthening are coupled, and the obtained graphene sheet layer is high in integrity and few in structural defect and can be directly used for manufacturing conductive composite materials and energy storage devices.

The invention relates to the field of gas sensors, and discloses a hydrogen sulfide gas sensor and a method for detecting the concentration of hydrogen sulfide in gas. The hydrogen sulfide gas sensor comprises a substrate and a gas sensitive material, a cavity is formed in the substrate, the gas-sensitive material is located above the cavity, and the two ends of the gas-sensitive material are connected with the gold electrodes on the substrate; the gas sensitive material comprises graphene fiber and metal oxide loaded on the graphene fiber. The metal oxide is selected from one or more than two of oxides of Zn, Cd, Cu, Ni, Pd, Pt, Co, Ir, Fe, Mn, Cr, Mo, W, V, Ti, Mg and Al; the specific surface area of the gas sensitive material is 80-150m < 2 > / g; the loading capacity of the metal oxide is 0.05 to 5 weight percent. The hydrogen sulfide gas sensor can be self-heated, has high sensitivity to hydrogen sulfide gas, and is suitable for being applied to the field of gas monitoring.

The invention provides a compressible high-thermal-conductivity graphene thermal interface material and a preparation method thereof. The preparation method comprises the following steps: preparing a graphene oxide film with low structural unit thickness by adopting a centrifugal spin-coating film casting method, performing limited thermal expansion delamination, compounding with polysiloxane, and performing directional lamination to obtain a highly-oriented graphene / organic silicon composite material. And applying shear stress after pressurizing and densifying along the normal direction of the graphene sheet layer, so that the graphene structure unit forms a continuous buckling structure which is high in density and easy to compress. The densification process promotes the interaction among delamination structure units, broadens a phonon transmission channel, inhibits phonon-boundary scattering, enhances the comprehensive heat-conducting property, plays a role in promoting stress transmission among graphene, and ensures the formation of a continuous buckling structure under shear stress. A continuous buckling structure and a relatively low structure unit thickness (llt in the graphene structure unit; and the compression modulus of the densified vertical graphene array is jointly reduced by means of high density, high thermal conductivity and high compressibility of an existing thermal interface material, and the method can be applied to the fields of new energy automobiles, high-power chips, aerospace electronic equipment and the like, and the problem that high density, high thermal conductivity and high compressibility of the existing thermal interface material are difficult to consider at the same time is solved.

The invention relates to a high-compaction lithium iron phosphate positive electrode material, a preparation method thereof and a lithium ion battery, and belongs to the technical field of batteries, the method adopts a two-step synthesis method, the first step adopts ferrous phosphate high-grinding sintering to prepare first-sintering large particles, and adopts in-situ doped iron phosphate low-grinding to prepare first-sintering small particles; 2, performing high grinding on the first-fired large particles, performing low grinding on the first-fired small particles, accurately controlling the sizes of the small particles, and stripping C3N4 through grinding to form g-C3N4; the large and small particles are mixed according to a certain mass ratio, and then secondary sintering is carried out to prepare the high-compaction high-capacity long-circulation lithium iron phosphate material, the advantages of different precursors are utilized, the particle composition is optimized, and the roundness of the large and small particles is better; meanwhile, the nitrogen-doped carbon layer is prepared by taking defect-type graphene and high-molecular organic nitride which are converted from C3N4 in a secondary sintering process as carbon sources, so that the conductivity and the cycle performance of the material are improved.

The invention discloses an ultrasonic phased array driven graphene oxide flow stripping and closed-loop regulation and control system and method, and the system comprises an ultrasonic phased array module, and a piezoelectric transducer array element in the ultrasonic phased array module controls sound beam focusing and energy distribution through a phase delay controller, and carries out the stripping of graphite oxide flowing in a flow channel; a micro-Raman spectrometer in the micro-fluidic-Raman detection module collects characteristic peak data of a graphene oxide sheet layer in a micro-fluidic chip in real time and sends the characteristic peak data to a signal analysis unit; and the feedback control module is used for receiving the layer number distribution data output by the signal analysis unit, dynamically adjusting ultrasonic parameters of the phase delay controller, and controlling the diverter valve to guide substandard products into a secondary treatment channel and finally return the substandard products to the flow channel for stripping again. The system and the method for stripping the graphene oxide based on coupling of the ultrasonic phased array and the micro-fluidic chip have the advantages of efficient stripping, accurate detection, closed-loop optimization and the like.

The present invention discloses a graphene-coated lithium iron phosphate cathode material and a preparation method thereof, belonging to the technical field of lithium iron phosphate cathode materials. First, iron phosphate is loaded on graphene, and by controlling the pH adjustment time, small-particle-size FePO 4 / GO and large-particle-size FePO 4 / GO are accurately obtained. Iron phosphate is loaded on single-walled carbon nanotubes to prepare FePO 4 / SWCNT. Then, the loaded material and a lithium source are subjected to a pre-calcination reaction to grow and form graphene-coated lithium iron phosphate. Finally, dopamine is oxidized and self-polymerized to form polydopamine, which is coated on the outer layer of the graphene-coated lithium iron phosphate. After calcination and carbonization, a double coating of porous carbon material and graphene is formed. The particle size distribution of the prepared cathode material is optimized by using iron phosphate materials with different particle sizes and shapes to improve its tap density, and the conductivity is improved by graphene coating, endowing the cathode material with excellent electrochemical performance.

The invention discloses a graphene / polyaniline composite film with a gradient structure and a preparation method and application thereof, the preparation method comprises the following steps: S1, preparing a coating template, and uniformly coating the coating template with a graphene oxide dispersion liquid to obtain a graphene oxide porous template; s2, performing electrochemical reduction on the graphene oxide porous template to obtain a reduced graphene oxide porous template; and S3, carrying out polyaniline electrodeposition on the reduced graphene oxide porous template to obtain the graphene / polyaniline composite film with a gradient structure. The graphene / polyaniline composite film prepared by the invention has a gradient structure, and can improve various ion energy storage characteristics and conductivity of the material.

The invention discloses a biaxial flexible strain sensor based on laser induced graphene. Comprising a flexible substrate, a flexible sensitive layer, a flexible spacing layer and a flexible upper cover, both the flexible substrate and the flexible upper cover are made of a polydimethylsiloxane (PDMS) material, the flexible sensitive layer is generated on a mixed substrate of polyimide (PI) and multi-walled carbon nanotubes (MWCNTs) through a laser ablation process, and then the sensitive layer is transferred to the PDMS substrate through a substrate transfer process. The flexible sensitive layer adopts an I-shaped structure, and two ends of the flexible sensitive layer are coated with electrode layer external wires. The method can be applied to the fields of wearable electronic equipment and medical monitoring. By means of the I-shaped structure, the sensitive layers in different directions can detect the strain in the main direction, and meanwhile interference caused by the strain in different directions is avoided. The preparation method is simple and efficient, a special gas environment is not needed, patterning preparation of graphene can be completed only through one step, and the production cost is reduced.

A method of electrochemical exfoliation, may include: electrochemically exfoliating a parent material comprising coke, wherein the electrochemically exfoliating comprises introducing the parent material into a porous chamber, applying pressure to the porous chamber to thereby compress the parent material in the porous chamber, and applying a potential bias to the parent material while at least a portion of the parent material is in contact with an electrolyte solution to produce a mixture of exfoliated material and unexfoliated parent material, wherein the exfoliated material comprises exfoliated graphene; and separating at least a portion of the exfoliated material from the unexfoliated parent material.

Method for making a porous graphene layer (5) comprising the following steps: providing a catalytically active substrate (1) to catalyse the graphene formation under chemical vapour deposition conditions, on its surface (3) being provided with a plurality of catalytically inactive domains (2); chemical vapour deposition on the surface (3) of the catalytically active substrate (1), the pores (6) in the porous graphene layer (5) being formed in situ due to the presence of the catalytically inactive domains (2); wherein subsequent to the chemical vapor deposition the porous graphene layer (5) is removed from the substrate (3), in that the exposed porous graphene layer (5) is subjected to an aqueous solution containing a dissolved oxidant, directly or indirectly followed by treatment of the exposed porous graphene layer (5) with an aqueous persulfate solution, directly or indirectly followed by lamination of a carrier layer onto the exposed porous graphene layer (5) from the side opposite to the catalytically active substrate (1) and mechanical separation of said carrier layer (16) with the exposed porous graphene layer (5) from said catalytically active substrate (1).

The invention discloses a paper-based electrode based on liquid metal assisted laser-induced graphene and a preparation method thereof.The paper-based electrode comprises a substrate layer, a functional layer, a conductive layer and a hydrophobic layer which are sequentially arranged, the substrate layer is made of paper, the functional layer is formed by coating liquid metal nanoparticles, and the conductive layer is formed by coating liquid metal nanoparticles. The conductive layer is an electrode formed by a laser-induced graphene technology, and the hydrophobic layer is a fluid control area formed by wax packaging. According to the invention, paper is used as a substrate, liquid metal is combined with a laser-induced graphene technology, surface modification is carried out through eutectic gallium indium (EGaIn), polyimide (PI) and N-methyl pyrrolidone (NMP) composite slurry, and then a conductive electrode pattern is formed on the surface of the paper substrate by using a laser-induced graphene (LIG) technology. The method has the advantages of simple preparation, low cost, environmental friendliness and the like, and the prepared paper-based electrochemical biosensor has excellent conductivity, mechanical flexibility and electrochemical activity.

The invention discloses a high-elastic graphene-based metamaterial and a preparation method thereof.The preparation method comprises the steps that a graphene oxide solution is processed through a wet method and extruded through a large-size flow channel, blocky graphene oxide hydrogel is obtained, a fluid subdivision device is additionally arranged in front of a solution spraying opening, graphene oxide sheets generate a velocity gradient difference when subjected to subdivision multi-flow-field shearing, and the high-elastic graphene-based metamaterial is obtained; graphene oxide hydrogel with C-shaped superstructure arrangement is obtained by rearranging a graphene oxide lamellar texture, and the high-elasticity graphene-based metamaterial is obtained after freeze drying and reduction treatment.

The invention discloses a graphene heat dissipation film with high vertical thermal conductivity and a preparation method thereof. The preparation method comprises the following steps: preparing graphene oxide slurry containing metal salt into a first graphene oxide wet film through a film forming process; adding and forming nanofibers on the first graphene oxide wet film to construct a vertical heat conduction path, and then adding the graphene oxide slurry to form a second graphene oxide wet film to form a multi-layer material; and carrying out drying, pre-oxidation treatment, vacuum carbonization treatment and graphitization treatment on the multi-layer material to obtain the graphitized film. The obtained graphene heat dissipation film is good in interface compatibility and small in interface thermal resistance, the heat conduction performance in the vertical direction is remarkably improved, and the excellent heat conduction performance can still be kept in the plane direction.

The invention discloses a method for preparing nitrogen-containing graphene by taking chitosan as a raw material, and belongs to the technical field of nitrogen-containing graphene. The preparation method comprises the following steps: uniformly coating a mixed solution of chitosan and acetic acid on the surface of a quartz base material by adopting a spin coating technology, then slowly heating and annealing the base material coated with the mixed solution in a nitrogen protection environment, after the temperature is naturally reduced to room temperature, lightly scraping off a chitosan film from the base material, placing the base material in a nitrogen atmosphere again, and carrying out two-step carbonization to obtain the chitosan / acetic acid composite material. After carbonization is completed, naturally cooling to room temperature to obtain a pre-carbonized product; and uniformly mixing the obtained pre-carbonized product with a regulating agglomeration agent according to a mass ratio of 1: 1. Then, two-step activation treatment is carried out, after activation is completed, after the system is cooled to the room temperature, a product is subjected to aftertreatment and drying, and a nitrogen-containing graphene product is obtained. Chitosan is spin-coated to prepare a film before high-temperature carbonization, and then an annealing reaction is carried out for a period of time. The conformation of the polymer fiber treated by the step is loose, and formation of a graphene layer is facilitated.

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 graphene-coated hard carbon negative electrode material and a preparation method thereof, and belongs to the technical field of hard carbon negative electrode materials. The preparation method of the graphene-coated hard carbon negative electrode material comprises the following steps: carrying out pretreatment and three-step soaking on coconut shells, carrying out biomass carbonization, mixing with a microbial suspension, and adsorbing to obtain a microbial adsorption type hard carbon material; and then carrying out surface treatment, chemical vapor deposition, impregnation, secondary chemical vapor deposition and annealing treatment on the microbial adsorption type hard carbon material to obtain the graphene coated hard carbon negative electrode material. The negative electrode material prepared by the method is high in first discharge capacity, high in first coulombic efficiency and good in cycle performance.

The present invention relates to a method for synthesizing graphene, and more particularly, to a method for synthesizing graphene by flash Joule heating (FJH). Such methods may be used to synthesize disordered graphene in large volumes, including low-defect disordered graphene. Such methods may further be used in the synthesis of composite materials and 2D materials.

The invention provides a magnetic confinement microwave plasma preparation method and system for coal-based graphene quantum dots, and relates to the technical field of graphene quantum dot preparation, and the method comprises the following steps: pretreating a coal raw material, removing impurities, and crushing the coal raw material to a preset particle size; detecting the coal quality parameters of the pretreated coal raw material, wherein the coal quality parameters at least comprise the contents of C, H and O elements; the coal quality parameters are input into a QYOA algorithm to be analyzed, and adjustment parameters of microwave power and reaction gas are obtained; feeding the pretreated coal raw material into a reaction cavity, and forming a three-dimensional confinement field in the reaction cavity through a magnetic confinement device; according to the method, magnetic confinement, microwave plasma, a QYOA algorithm and ultrasonic aftertreatment are organically combined to form a synergistic effect, dissociation of carbon clusters is promoted through the synergistic effect of the magnetic confinement and the microwave plasma, the yield of the coal-based graphene quantum dots is increased to 30% or above from less than 10% of a traditional method, the production efficiency is improved, and large-scale production is facilitated.

The invention discloses a high-valued utilization method of waste biomass, which comprises the following steps: firstly, applying current to the waste biomass containing carbon element to generate Joule heat, and generating a high-temperature environment in an extremely short time, so as to realize rapid carbonization of the biomass; then conductive carbon black or other auxiliaries do not need to be additionally added, current is applied again to generate Joule heat, a higher-temperature environment is generated within an extremely short time, and graphitization transformation of the biochar is achieved. Compared with traditional pyrolysis, hydrothermal, roasting or chemical vapor deposition methods, the flash Joule thermal method has the advantages of being easy and convenient to operate, short in consumed time, low in energy consumption, high in efficiency, high in safety, environmentally friendly and the like, and is suitable for high-value utilization of various biomass resources and green preparation of graphene materials.

To provide an exothermic coating capable of producing using carbon materials produced with vegetable raw materials as a carbon source maintaining strength, and CO2 reduction and an exothermic coating capable of maintaining the strength even in various temperature zones.SOLUTION: It is characterized by using carbon materials containing silicon components from plant-based raw materials with 5% or more silicon content as pigments, ranging from 1 wt% to 50 wt%. Moreover, by mixing carbides 19 with a high number of functional groups with graphene 113, it is also possible to supply not only direct current but also high voltage power such as alternating current while stabilizing strength.SELECTED DRAWING: Figure 3

The invention provides graphene production equipment, and relates to the technical field of linear compound machines, the graphene production equipment comprises a base and a preparation cylinder rotatably arranged at the top of the base, and a mixing mechanism is arranged at the top of the base; the mixing mechanism comprises a lifting component arranged at the top of the base and a driving component arranged on the lifting component; the stirring part is arranged at the output end of the driving part, the disturbance radius of the stirring part can be expanded relative to the axis of the preparation cylinder, the springing part is arranged on the lifting part and can drive the stirring part to vertically reciprocate relative to the preparation cylinder when the stirring part works, and a rotating mechanism used for driving the preparation cylinder to rotate in a reciprocating mode is further arranged at the top of the base. According to the device, a mixed solution for preparing graphene can be stirred in multiple directions, particles attached to the inner wall of the device can be scraped to enable the mixed solution to react continuously and thoroughly, in addition, the mixed solution can be heated uniformly, and then the solution reaction speed and the graphene preparation speed are increased.

The invention relates to the technical field of graphene processing, and particularly discloses a nano graphene powder preparation method which comprises the following steps: weighing a graphite raw material; opening a discharge valve of the feeding cabin, and feeding the graphite raw material into the pressure stabilizing cabin; a graphite raw material is sucked into a first-stage jet mill high-pressure cabin from a pressure stabilizing cabin, first-stage jet milling is conducted, and a first-stage abrasive material is obtained; the first-stage grinding material with the thickness not larger than 10 micrometers is conveyed to a second-stage jet mill high-pressure cabin; processing the first-stage abrasive material by a second-stage jet mill high-pressure cabin to obtain a second-stage abrasive material; the second-stage grinding material with the thickness not larger than 100 nanometers is conveyed to a flow energy depolymerization cabin; the flow energy depolymerization cabin is used for processing the secondary grinding material, and nano graphene powder is obtained through screening; the high-purity graphite raw material is processed through a three-stage gradient processing framework, a negative feedback regulation scheme is introduced in each processing link, the quality of products in different stages is controlled, a progressive processing technology is constructed, and the product rate is greatly increased.