8371results about How to "Avoid reunion" patented technology

The invention belongs to the fields of material synthesis and energy technology, and especially relates to a graphene/metal oxide composite cathode material for lithium ion batteries and a preparation method thereof. Grapheme is dispersed into various metal oxide precursor salt solutions; a graphene/metal oxide compound is obtained directly by a hydrothermal method, or an graphene/metal oxide compound is obtained by a liquid in-situ polymerization method or a coprecipitation process; and the graphene/metal oxide compound is obtained by heat treatment or hydrothermal treatment. In the invention, the novel three-dimensional composite cathode material of graphene-coated metal oxide or graphene-anchored metal oxide is prepared by carrying metal oxide particles with graphene as a carrier. The obtained composite material can be used as a lithium ion battery cathode, which has a high specific capacity, excellent cycle stability and rate capability, and is expected to be used as a lithium ion battery cathode material with a high energy density and a high power density.

A wet chemical process for preparing iron lithium phosphate includes mixing the solution or suspensions of Li source compound, Fe source compound, P source compound, doping element compound or electric conducting agent, and precipitant, reaction at 5-120 deg.C for 0.5-24 hr while stirring, filtering, washing, baking to obtain nano precursor, quickly heating to 500-800 deg.C in non-air or non-oxidizing atmosphere, calcining for 5-48 hr, and cooling. Its advantages are easy control, high uniformity and electric conductivity.

The invention relates to a method for preparing graphene powder in large scale, which is characterized by comprising the following steps of: firstly, uniformly peeling graphene oxide into a graphene oxide suspension solution; then, atomizing the graphene oxide solution by using the spray drying technology comprising spray pyrolysis drying and spray freeze drying, and removing a solvent to obtain graphene oxide powder; and finally, oxidizing grapheme by using the non-expansion heat treatment process to obtain non-agglomerative graphene powder. The continuous preparation process of the spray technology and the non-expansion heat treatment process ensure the large-scale preparation of the graphene powder. The prepared graphene powder comprising intermediate product graphene oxide powder does not have agglomeration and has good dispersivity in the solvent. The graphene powder is used as a filling material to prepare high strength composite materials, conductive composite materials, novel air-tight flame-retardant composite materials, novel nanodevices and the like.

The invention discloses a manganese/lithium phosphate of lithium iron battery positive pole material and a production method thereof, the technical issue to be solved is to improve electrochemical performances of the positive pole material. The material of the invention includes substrates of manganese/lithium phosphate which are covered by a carbon material covering layer, the lithium covering the manganese/lithium phosphate behind the carbon material covering layer is spherical and has microscopic characteristics of being near spherical, rhombic, tapered, tabular, layered or/and block-shaped as well as of having 0.5-30 mum long and short axles. The production method comprises the following steps of: production of nanometer particles, liquid phase mixed reaction, production of precursor, sintering treatment, covering organic substances. Compared with the prior art, the invention improves the electron conductivity of the manganese/lithium phosphate by covering with carbon liquid phase, the carbon sufficiently covers active materials to efficiently prevent particle aggregation, the invention has the characteristics of about 4V of discharge voltage, high discharge and charge capacitance, excellent circulation stability, high safety, simple process, low cost and little influence on the environment.

The invention relates to a carbon-coated nano silicon/graphene/cracked carbon layer composition material, a preparation method thereof, and a lithium ion battery including the composition material. The composite material comprises spherical particles formed by uniformly dispersing carbon-coated nano silicon in graphene sheets, and a cracked carbon layer which coats the surfaces of the spherical particles. The carbon-coated nano silicon comprises nano silicon and carbon coating layer which coats the surface of the nano silicon. The method is simple, has excellent process performance and is environment-friendly. The carbon-coated nano silicon/graphene/cracked carbon layer composition material has stable structure and high compact density, has excellent performance when being used as an anode material of the lithium ion battery, has high anode capacity, excellent rate capability and cyclic performance, is more than 1500 mAh/g in first-time reversible capacity, is more than 90% in first-time coulomb efficiency and is more than 90% in 500-time cyclic capacity retention ratio and has low expansion.

The invention discloses composite hydrogel for adsorption of metal ions and a preparation method thereof. The hydrogel comprises, by weight, 5-95 parts of polyvinyl alcohol, 5-95 parts of chitosan, 0.1-20 parts of modified graphene oxide and 2-6 parts of sodium alginate, the weight ratio between the polyvinyl alcohol and the chitosan is (5: 95)-(95: 5), modified graphite oxide includes modified graphene oxide modified by dopamine and/or modified graphene oxide modified by ferroferric oxide, all components are uniformly mixed in a certain sequence, and the composite hydrogel is obtained under special conditions. The composite hydrogel for adsorption of the heavy metal ions and the preparation method thereof have the advantages that high speed, high efficiency, high adsorption capacity and high selectivity are achieved, the adsorption effect on the heavy metal ions is remarkable, meanwhile, the preparation process is simple, and the operability is high.

The invention discloses a graphene/carbon black thermoplastic resin master batch with high dispersibility and a preparation method thereof. The graphene/carbon black compound in the master batch is formed in an electrostatic self-assembly manner, and comprises 10-50% of graphene, 5-20% of carbon black, 0.5-10% of surfactant, 10-65% of carrier resin and 2-10% of assistant. The preparation method comprises the following steps: (1) compounding and dispersing graphene by adopting the surfactant to control the positive electricity of the graphene surface; (2) forming a stable graphene/carbon black compound from the modified graphene and carbon black with positive electricity through electrostatic incorporation in a self-assembly manner; (3) preparing the graphene/carbon black thermoplastic resin master batch with high dispersibility by matching with a solution blended process, a melt-blending method and an in-situ polymerization method; (4) adding the assistant to extrude and pelletize, so as to prepare the graphene/carbon black/thermoplastic resin master batch particles after processing the master batch. By adopting the obtained master batch, the problems of difficult charging of graphene powder, uneven dispersion, dust pollution, unstable product performance and the like are solved.

The invention provides a method for preparing a hydrogenation catalyst with high activation. A disposition method is adopted to carry out step-by-step loading to the active components of the metals of VIB and VIII families; the VIB metal comprises tungsten or molybdenum, while the VIII metal comprises nickel or cobalt; a carrier is alumina. The loading of VIB metal takes a corresponding soluble salt as raw material, an acid solution as a precipitator and a cationic surface active agent as a dispersant. In a hydrothermal condition, the corresponding soluble salt, the acid solution and the cationic surface active agent produce metallic oxide particles by a liquid deposition reaction; the loading of VIII metal also takes a corresponding soluble salt as raw material and carbamide as a precipitator; the adding of the precipitator and the generation of precipitation are separated by controlling reaction temperature in sections and even precipitation is realized to disperse the particles of the active components on the carrier evenly. The hydrogenation catalyst prepared shows good effects in the respects of desulfurization and denitrification activation and can greatly reduce the usage of the active components.

The invention discloses a graphene-based nano iron oxide composite material and a preparation method thereof. By the method, iron oxide nano granules with uniform diameter and controllable shape and components can be loaded on graphene. The method comprises the following steps of: uniformly dispersing graphite oxide into deionized water by adopting an ultrasonic method to obtain graphene oxide solution; adding an iron salt precursor into the obtained solution and mixing the precursor and the solution uniformly, adjusting the pH of the solution, and hydrolyzing the iron salt; putting the mixed solution into a reaction kettle and performing hydrothermal reaction; and finally, cleaning and freeze-drying the obtained product to obtain the graphene-based nano iron oxide composite material. The raw materials are common and easily obtained, the cost is low, and the preparation process is simple, safe and environmentally-friendly; the prepared graphene-based nano iron oxide composite material has good structural stability and monodispersity; when the composite material is used as a lithium iron battery electrode material, the charge/discharge capacity can reach over 1,000mAh/g; and the composite material has good multiplying power performance and cycle life.

The invention relates to an aqueous nano porous corrosion-resistant heat-insulated coating material and a preparation method for the corrosion-resistant heat-insulated coating material and particularly relates to an aqueous corrosion-resistant heat-insulated coating material, which has a nano porous structure, prepared through forming an aqueous-phase uniform three-dimensional-network nano porous structure by taking thixotropic colloid as a template agent and adding a film forming agent, a reinforcing powder material, a functional powder material and admixtures. The preparation method for the corrosion-resistant heat-insulated coating material, disclosed by the invention, is simple and easy in operation and low in production cost, is environment-friendly and safe and is beneficial to mass production. The nano porous corrosion-resistant heat-insulated coating material disclosed by the invention has excellent heat insulating and corrosion resisting properties and can be applied to the heat insulating and corrosion resisting of equipment such as high-temperature furnace hearths, pipelines and valves in the fields of aerospace and military industries, metallurgical forging, petroleum refining, electric power and the like, so that the safety of use and the level of energy saving and consumption lowering are improved.

The invention discloses a preparation method of a single-crystal-morphology lithium ion battery ternary positive material. The method comprises the following steps: (1) preparing an inflorescence-shaped ternary positive material precursor particles by clustering lamellar primary particles in a coprecipitation method, wherein the D50 of the precursor particles is 2-5micron, the BET is more than 100m<2>/g, and the valences of nickel, cobalt and manganese are +2; (2) mixing a precursor obtained by adopting the coprecipitation method with auxiliaries to obtain a mixture 1, and performing high-temperature sintering on the mixture 1 at the temperature between 600-950 DEG C so as to obtain a round-likely roundness type oxide; (3) mixing the round-likely roundness type oxide precursor obtained by the high-temperature sintering with a lithium salt so as to obtain a mixture 2, and performing sintering on the mixture 2 at the temperature between 700-1000 DEG C so as to obtain a product; and (4) dispersing the product obtained by sintering in the step (3), and performing heating treatment on the dispersed product at the temperature between 780-1000 DEG C so as to obtain the single-crystal-morphology lithium ion battery ternary positive material. The prepared positive material is made from the uniform single-crystal primary particles with good dispersibility, and the problem that the primary particles are easy to cluster in the high-temperature sintering process in a conventional method can be effectively overcome.

The invention discloses novel nano calcium carbonate used for a plastic film and a preparation method thereof. A Ca(OH)2 suspension and CO2 are carbonized in a reactor to generate the nano calcium carbonate, and then the obtained nano calcium carbonate is subjected to liquid phase coating treatment or is directly subjected to mixed coating by using dried nano calcium carbonate and a surfactant to obtain nano calcium carbonate powder which is highly dispersed and surface-activated. The invention has the advantages that: the process is simple, the nano calcium carbonate is effectively dispersed in a polymer and a remarkable enhancement effect can be achieved on the premise of ensuring the transparency. The nano calcium carbonate prepared by adopting the invention can remarkably improve the mechanical property of a polyolefin material; after the nano calcium carbonate is used for polyethylene plastic, the tension strength of the material is greatly improved; and after the nano calcium carbonate is used for a polyolefin film, a fish eye is free, and the high transparency of the film is maintained.

The invention relates to a method of the technical field of environment protection and in particular to a high salinity wastewater treatment corrosion-resistant anti-fouling membrane as well as a preparation method and application thereof. The preparation method comprises the following steps: by taking a mixture of clay minerals and oceanic nodule minerals as inorganic nano particles, modifying the inorganic nano particles with dopamine, and combining a PVDF (Polyvinylidene Fluoride) polymer with the nano particles, thereby obtaining the high salinity wastewater treatment corrosion-resistant anti-fouling membrane. The invention aims to improve the water flux, the corrosion resistance and the pollution resistance of the membrane, the mixture of the clay minerals and the oceanic nodule minerals is adopted as the inorganic nano particles, the inorganic nano particles are subjected to surface modification with dopamine, combination of the nano particles and the PVDF is promoted, the obtained membrane is capable of efficiently treating high salinity wastewater and meanwhile has properties of corrosion and fouling resistance; in addition, the dopamine has a great amount of hydrophilic groups of amino, particle aggregation is prevented, the hydrophilcity of the membrane is improved, and the difficulties that materials are not uniformly dispersed and are easily dropped off in the use process are solved.

The invention relates to a preparation method of a graphene and manganese dioxide nanocomposite material, comprising: (1) stirring and mixing graphite, potassium nitrate and concentrated sulfur evenly, adding potassium permanganate, and reacting at 30-40° C. for 20-40 minutes , add deionized water at room temperature, add hydrogen peroxide after reacting for 15 to 30 minutes to obtain graphite oxide; (2) disperse the above graphite oxide in water, add hydrazine hydrate, and react at 95°C for 1 to 24 hours to obtain graphene (3) ultrasonically disperse the graphene in a saturated potassium permanganate solution, add acid, and react at 60-80° C. for 1-5 hours to obtain graphene and manganese dioxide nanocomposite material. The invention has the advantages of simple reaction, easy control, convenient operation and simple process; the obtained composite material has broad application prospects and can be used for catalysts, biosensing materials, electrode materials of lithium ion batteries and supercapacitor electrode materials, and the like.

The invention discloses a lithium ion battery phosphatic composite cathode material and a preparation method thereof. The composite material is a multinuclear core shell structure composed of a plurality of cores and a housing layer, the cores are lithium iron phosphate particles wrapped by lithium vanadium phosphate and the housing layer is amorphous carbon. Preparation of the lithium iron phosphate particles wrapped by lithium vanadium phosphate comprises the following steps: preparing precursor sol with a sol gel method, adding lithium iron phosphate powder to disperse uniformly, carrying out spray drying on the above mixture, calcining the above resultant in inert gas, and followed by cooling and grinding to obtain the lithium iron phosphate particles wrapped by lithium vanadium phosphate. Preparation of the composite cathode material comprises the following steps: dissolving a carbon source compound into deionized water, adding core materials, dispersing the above resultant uniformly, carrying out second spray drying, calcining the above resultant in inert gas, and followed by cooling to obtain the composite cathode material. The composite material prepared in the invention has good electronic conduction performance, good ionic conduction performance and excellent electrochemistry performance. Because of existence of lithium vanadium phosphate, energetic density of a material is raised. Because of the multinuclear core shell structure like nano/micro structures, the composite material has good processing performance, and tap density of the material is greatly raised.

The invention provides a lithium ion battery cathode material and a preparation method of the lithium ion battery cathode material as well as a lithium ion battery. The lithium ion battery cathode material comprises an inner core, a middle layer outside the inner core and an outer shell wrapping the middle layer, the inner core is Si-C particles, the middle layer is a foam layer, the outer shell is an amorphous carbon layer and the Si-C particles are formed by Si particles and C materials. Compared with the prior art, a middle carbon foam layer existing between the Si-C particle inner core and the amorphous carbon outer shell can form an conductive network structure, thus improving conductivity of a material and buffering enormous volume change of Si particles in the charge-discharge processes; and the amorphous carbon outer shell layer can maintain the core-shell structure of the cathode material, and the cladding layer of the core-shell structure can buffer the volume change, improve cycling stability of electrodes, reduce contact between active substances and an electrolyte, improve first coulombic efficiency of an electrode, prevent nanoparticle aggregation and enhance electrode conductivity.

The invention relates to shear thickening fluid based on a molecular colloid, as well as a preparation method and an application of the shear thickening fluid. The shear thickening fluid consists of an organic solvent and a molecular colloid system formed by inorganic nano grains, boric acid, hydroxyl silicone oil and a plasticizing agent, and is used for dipping high-property fiber fabric and preparing a protective material to improve a puncture-proof property of the material; the preparation technology is simple; the preparation period is short; the controllability of an operation is high; the stability of the property of a product is improved; the energy consumption is reduced; and moreover, large-scale production is facilitated.

The invention belongs to the field of the material science and in particular relates to a high-performance graphene/cellulose composite hydrogel and aerogel and preparation methods thereof. The preparation method of the high-performance graphene/cellulose composite hydrogel comprises the following steps: (1) adding graphite oxide to ionic liquid and ultrasonically dispersing to obtain an ionic liquid solution of the graphite oxide; preparing an ionic liquid solution of cellulose having the mass fraction of 4-6wt%; (2) adding a reducing agent to the ionic liquid solution of graphite oxide, and reducing at 80-100 DEG C for 2-24 hours, thereby obtaining an ionic liquid mixed solution of reduced graphite oxide; (3) mixing the ionic liquid mixed solution of reduced graphite oxide with the ionic liquid solution of cellulose; (4) defoaming the obtained final mixed solution, regenerating by use of a coagulating bath, and washing, thus obtaining the graphene/cellulose composite hydrogel. The composite gel prepared by the preparation method has excellent properties, particularly has excellent the mechanical properties, and can be widely applied.

The invention discloses a method for preparing a grapheme/silver nanoparticles composite material by using a liquid phase method. N and N-dimethyl formamide (DMF) serve as a reducing agent, grapheme powder with purity as high as 99% serves as a carrier, and silver forms a core and grows on a grapheme layer under a soft reaction condition to obtain the grapheme/silver nanoparticles composite material. The preparation method has the advantages of being simple, convenient, rapid and high-efficient in process, the grapheme/silver nanoparticles composite material prepared by using the method is high in purity and less in impurity content, and silver nanoparticles generated on the surface layer of the grapheme are small in particle size, uniform in distribution and high in bond strength with the grapheme. The silver nanoparticles are closely absorbed on the grapheme layer, aggregation of the grapheme is effectively avoided, and application of the grapheme/silver nanoparticles composite material in the fields of electron, catalysis, antibiosis and the like can be enlarged.