54results about How to "Control specific surface area" patented technology

The present invention belongs to a high-performance lithium-ion battery cathode material and a method for preparing the same; solvent, resin and asphalt are added to a container and graphite grains are then added by stirring; the solvent is steamed out through heating up and decompression to form the graphite coated with resin and asphalt which is then put to an inert atmosphere charring furnace for heat treatment; the graphite is cooled to the cycle process less than 100 DEG C after 1 hour to 10 hours; material is taken out, smashed and sieved to grains with grain diameter less than 5 um; after the accumulated volume fraction of grains is less than 10 percent, the high-performance lithium-ion battery cathode material is achieved. As the graphite grains are covered with mixed high molecular polymer made of resin and asphalt, not only the advantages of the resin and asphalt are used, but also the resin has the characteristics of solving asphalt and having condensation polymerization with asphalt, thereby the uniformity, operability and electrical property of covering the graphite grains are improved. By adjusting the proportion of asphalt to resin and controlling the specific surface area of covering graphite grains, the invention has different cycle stability and multiplying power property.

The invention discloses a preparation method for nanometer yttrium oxide powder, belonging to the technical field of preparing superfine rare earth powder. The method comprises the steps of dropping yttrium-containing inorganic acid salt in alcohol-water mixed solution which contains a precipitant and a static stabilizing agent, then adding a surfactant after finishing dropping, stirring, aging and separating the reaction system to obtain precipitate, then carrying out cleaning and washing, vacuum drying and calcinating to the precipitate to obtain the nanometer yttrium oxide powder. According to the preparation method, by applying the back titration, alcohol-water mixture solution and surfactant, not only can yttrium ions be favorably separated out and crystallized, but also the particle size of the crystals and the specific surface area of the crystal particles can be better controlled, so that the prepared nanometer yttrium oxide powder has smaller particle size, narrow particle size distribution and larger specific surface area, thus further having higher sintering activity; the preparation method is simple in technology, short in synthesis route, easy to control, capable of remarkably improving the purity and yield of products, and suitable for industrial production.

The invention belongs to the technical field of preparation of rare earth oxide and particularly relates to a preparation method of nano neodymium oxide with large specific surface area. The method comprises the following steps: adding a surfactant into a neodymium-containing inorganic salt solution; dropwise adding a precipitant into the solution, and stirring for sufficient reaction of the two solutions; aging to obtain a precipitate; and washing the precipitate with deionized water, and performing vacuum drying and ignition to obtain nano neodymium oxide with large specific surface area. In the invention, through the application of the surfactant and control of the precipitant concentration and dropwise adding speed, according to TEM detection, the primary particle size of the prepared nano neodymium oxide is 20-60nm, and the specific surface area is 60-100m<2>/g. The method provided by the invention has the advantages of simple technology, relatively low cost and high controllability, remarkably improves the product purity and yield, and is environment-friendly and suitable for industrial production.

Melamine resin pellets are obtained through one-step condensation of melamine and formaldehyde, the melamine resin pellets used as templates are coated with polypyrrole by using pyrrole as a nitrogensource and a carbon source and ammonium persulfate as a catalyst; the melamine resin pellets are gradually decomposed in the roasting process by controlling roasting to obtain nitrogen-doped porous hollow carbon spheres; and finally, the material is used in a lithium ion battery negative electrode. By using the melamine resin pellets instead of traditional silicon dioxide pellets, the problem of environmental pollution caused by etching of a silicon dioxide hard template with use of toxic reagents such as hydrofluoric acid in a traditional hard template method is avoided. Because the melamineresin pellets can generate a large amount of gas in the decomposition process, pores can be further formed in the pore walls of the hollow carbon spheres. Because the material is uniform in morphology, large in specific surface area and of a hollow structure, volume expansion can be relieved, and high specific capacity and cycle stability are shown in the lithium ion battery.

The invention discloses an air-flow vortex balling machine for producing spherical graphite, which consists of a machine body, a balling drive device and an internal classification machine drive device, wherein an internal classification machine, a powder balling module and a cooling system are arranged in the machine body. In the invention, an internal balling module and a classification module are rationally arranged, and thus, the air-flow vortex balling machine for producing the spherical graphite is provided. The air-flow vortex balling machine can ensure that the graphite powder undergoes the physical processes of thinning, shearing, collision, friction, coiling, uniting and densification in an air-flow vortex balling room or can realize the combination of a physical balling process and a mechanical powder thinning process to prepare the spherical product. The indexes, such as sphericity, grain fineness distribution, tap density, apparent density, actual density and special surface area, of the spherical graphite powder can be controlled in the range of pre-determined values; the quality is stable; the yield can be improved by over three times; and over 50 percent of energy consumption can be reduced.

The invention relates to lithium ion battery cathode material natural graphite, in particular to a method for improving electrical property of natural graphite. The method is characterized by comprising the steps of firstly, adding solvent into a reactor, stirring, sequentially adding asphalt, polycondensate or organic mixture containing polycondensate, stirring, adding natural graphite, and evaporating solvent; secondly, drying and solidifying organic polymer coated on the surface of the graphite for 8-16 hours; thirdly, crushing obtained graphite particles; fourthly, performing hot treatment at 400-800 DEG C for 5-20 hours; fifthly, processing at 100-420 DEG C for 3 minutes to 25 hours; performing hot treatment at 800-1350 DEG C for 1-15 hours; and seventhly, crushing the graphite particles again until D50 particle size of the graphite particles ranges from 10 micrometers to 20 micrometers. By the method, uniformity and operability of polymer-coated graphite particles are improved, and comprehensive electrical property of the polymer-coated graphite particles is also improved.

The present invention relates to a copper-iron-carbon aerogel electrode preparation method. According to the method, resorcinol, formaldehyde, water, sodium carbonate, iron acetylacetonate and copper acetate monohydrate are uniformly mixed in a reaction container according to a certain ratio, a polymerization reaction is performed for a certain time at a certain temperature to prepare a wet gel, the wet gel is dried, programming heating and cooling is performed to prepare the copper-iron-carbon aerogel electrode, and the prepared copper-iron-carbon aerogel electrode is activated sequentially through CO2 and N2 so as to be used as the cathode in the degradation pool to degrade organic pollutants such as dimethyl phthalate and the like. Compared to the method in the prior art, the method of the present invention has advantages of simple preparation process, high activity, low treatment cost for degradation of organic pollutants such as DMP and the like, simple treatment process, flexible degradation, and the like.

The invention discloses a fluorine and nitrogen co-doped three-dimensional graphene material. The fluorine and nitrogen co-doped three-dimensional graphene material is prepared by taking polytetrafluoroethylene and melamine as precursors through mixing and uniformly grinding and carrying out a one-step carbonization method; fluorine and nitrogen elements of three-dimensional graphene are uniformlydistributed; the specific surface area is 1200 to 1400m<2>g<-1> and the total pore volume is 2.5 to 2.9cm<3>g<-1>; the specific surface area of the material can be greatly regulated and controlled tobe 50 to 1600m<2>g<-1> through changing the carbonization temperature and the total pore volume is regulated and controlled to be 0.2 to 3.2cm<3>g<-1>. The one-step carbonization preparation method comprises the following steps: 1, mixing the raw materials; 2, carrying out a one-step carbonization method. Three-dimensional graphene grids in the material are uniform, and the fluorine and nitrogenelements are uniformly distributed; the repeatability is good and the carbonization temperature is moderate; the material is synthesized through one-step carbonization and a technology is simple and easy to operate. The material has a wide application prospect in the field of super-capacitors and a carbon functional material.

The invention discloses a lithium iron manganese phosphate/carbon-coated ternary material and a preparation method thereof, a lithium ion battery positive electrode and a lithium ion battery. The method comprises the following steps: 1) carrying out first ball milling on Fe2O3, Mn3O4, LiH2PO4 and a first organic carbon source, and carrying out first drying to obtain a precursor 1; 2) placing the precursor 1 in an air atmosphere, and carrying out heat treatment to obtain a precursor 2; 3) carrying out second ball milling on the precursor 2 and a second organic carbon source, and carrying out second drying to obtain a precursor 3; 4) sintering the precursor 3 at a constant temperature under the protection of an inert atmosphere to obtain a LiMn(1-x)FexPO4/C composite material; 5) dispersingthe LiMn(1-x)FexPO4/C composite material, a binder and a conductive agent in an oil solvent to prepare slurry, and 6) coating the surface of an electrode sheet prepared from a ternary material with the slurry, and drying The preparation method is simple and easy to operate, low in cost and excellent in product electrical property.

The invention discloses a method for preparing nanocrystalline cobalt-aluminum spinel (CoAl2O4) pigments through low-temperature combustion, which belongs to the field of nanocrystalline pigment preparation. The present invention is with soluble aluminum salt (aluminum nitrate, aluminum acetate, aluminum sulfate), soluble cobalt salt (cobalt nitrate, cobalt acetate, cobalt sulfate), citric acid or urea as starting material, Co2+: Al3+: citric acid three The mixing molar ratio is 1:(2-3):(1-6), or the mixing molar ratio of Co2+:Al3+:urea is 1:(2-3):(3-15). The solutions are mixed to form a complex, and citric acid or urea is used as a complexing agent and also as a fuel. The mixed solution is ignited by electric heating or microwave heating to obtain a fluffy powder, and then heat-treated at 500-1000°C to obtain nanocrystalline CoAl2O4 with a particle size of 10-100nm. The present invention is characterized in that the technological process is simple and efficient, and the combustion process is completed within 15 minutes. The process is low in energy consumption, easy to operate, and suitable for large-scale industrial production.

The invention discloses a preparation method of a hydrodeoxygenation catalyst with high hydrothermal/mechanical stability. The preparation method comprises the following steps: (1) preparing MoNi composite oxide powder; and (2) preparing a bulk type MoNi composite oxide catalyst, namely uniformly mixing the MoNi composite oxide powder, a binder and powder of sesbaria cannabina, dropwise adding 3% dilute nitric acid, performing strip extrusion for forming, and roasting for 2-5h in a muffle furnace at the temperature being 400-800 DEG C to obtain the bulk type MoNi composite oxide catalyst, wherein the binder is selected from two or more of magnesium aluminate spinel, kieselguhr and a molecular sieve binder. In the forming process of the catalyst, the binder is prepared from a material having relatively high hydrothermal resistance and mechanical stability, so that the bulk type MoNi composite oxide hydrodeoxygenation catalyst having high hydrothermal/mechanical stability, and activity is obtained, the edgewise comprehensive strength of the bulk type catalyst can be up to 90-140N/cm, and the hydrothermal/mechanical stability of the prepared catalyst can be obviously improved.

The invention belongs to the technical field of material preparations, and particularly relates to a treatment method of a porous carbon carrier for noble metal catalysts. The method treats the porous carbon carrier by using an oxidation reduction process, and comprises the following steps: firstly, treating the porous carbon carrier by using strong acid, then, adding a strong oxidant for oxidizing the treated porous carbon carrier to obtain oxidized form porous carbon, and at last, reducing the oxidized form porous carbon by using a reducing agent to obtain surface treatment porous carbon. By adopting the method, the specific surface area, pore passage structure and pore diameter of the carbon carrier can be improved and controlled, and meanwhile the hydrophilcity of the carbon carrier and the binding ability of the carbon carrier for the noble metal catalyst can be enhanced. By using the porous carbon loaded noble metal treated by the method, a carbon loaded noble metal catalyst with excellent comprehensive performance can be obtained. The processing method is simple, and low in cost, and can be used for scale production, and the yield is high.

The invention discloses a calcium carbonate preparation method for accelerating a carbonatation reaction and belongs to the technical field of calcium carbonate powder preparation. The calcium carbonate preparation method for accelerating the carbonatation reaction comprises the steps that the inner wall of a carbonatation reaction kettle is coated with a carbon dioxide gas adsorption material, and after the coating material fixed on the inner wall of the reaction kettle, by using the reaction kettle which is improved through coating, the carbonatation reaction is conducted to prepare precipitated calcium carbonate. According to the calcium carbonate preparation method, the problems are solved that in the prior art, prepared calcium carbonate is long in reaction time and uneven and unstable in product quality.

The invention provides a preparation method of magnesium hydroxide powder. The method comprises the following step: pulse current is applied in a reaction system when light calcined magnesia is utilized to prepare the magnesium hydroxide powder via hydration reaction. The magnitude of the pulse current applied in the reaction system is 5-1,000 A, and the used pulse frequency is 50-2,000 Hz. By adjusting the magnitude of the pulse current and the pulse frequency, the specific surface area, average particle size and microstructure and morphology of the magnesium hydroxide are controlled by the invention. Compared with the prior art, the preparation method provided by the invention has the following advantages: the process is simple, the cost is low, and the specific surface area, average particle size and microstructure and morphology of the magnesium hydroxide are easy to control.

The invention discloses a method for loading nanoscale zero-valent iron on the surface of quartz sand. The method comprises the steps of carrier pretreatment, electrolyte membrane assembling, ferrous ion uploading and reducing. The carrier pretreatment process particularly comprises the following steps that the quartz sand is weighed and immersed into a 15-30 g/L sodium persulfate solution with the pH ranging from 2 to 3, ultrasonic treatment is conducted at 60-70 DEG C, the treated quartz sand is cleaned with deionized water and then immersed into a 15-30 g/L sodium persulfate solution with the pH ranging from 12 to 13, ultrasonic treatment is conducted at 60-70 DEG C, and the treated quartz sand is cleaned with deionized water. According to the method for loading the nanoscale zero-valent iron on the surface of the quartz sand, the loading capacity and the particle size of the nanoscale zero-valent iron can be controlled, the reaction activity of the zero-valent iron can be effectively enhanced, and the method is suitable for restoration of groundwater.

The invention discloses a preparation method of an immobilized catalytic particle metal felt for producing biodiesel, aiming at solving the problems of an existing catalyst that the stability is poor,the service life is short and the catalytic efficiency is low. The preparation method comprises the following steps: carrying out ultrasonic washing on the metal felt with absolute ethyl alcohol andwater, and drying; preparing ZrOCl2.8H2O and nitrate into a mixed water solution; stirring and adding ammonia water until the pH (Potential of Hydrogen) is 9 to 10, so as to obtain flocculent sediment; standing at room temperature; then filtering and washing until no Cl<-> exists so as to obtain a filter cake; drying and grinding to obtain a powdered material; adding the powdered material into anH2SO4 solution to form a mixture; adding the dried metal felt into the mixture; after immersing, drying; roasting under an inert atmosphere at 400 to 600 DEG C for 3 to 7h to obtain the immobilized catalytic particle metal felt. The immobilized catalytic particle metal felt prepared by the preparation method has the advantages of high catalytic efficiency and mechanical strength, good stability and long service life; the preparation method has a simple technology and industrialized production is easy to realize.