154results about "Metal borides" patented technology

The invention discloses a rare earth boride nano material as well as a preparation method and application thereof. The phase state of the rare earth boride nano material is REB6 or REB4; the preparation method comprises the following steps: S1, respectively weighing a compound raw material containing an RE element and a compound raw material containing a B element; s2, adding an additive, and fully grinding; s3, reacting under the protection of inert gas; s4, after the reaction is finished, excessive methanol is added, centrifugal separation is performed after no bubbles emerge, and a precipitate A is reserved; s5, adding diluted hydrochloric acid for soaking, and performing centrifugal separation again to reserve a precipitate B; and S6, washing the precipitate B with deionized water, and drying to obtain the rare earth boride nano material. According to the preparation method disclosed by the invention, a normal-pressure and low-temperature preparation method is adopted, the pure-phase rare earth hexaboride nanocrystal can be obtained at normal pressure and the temperature as low as 300 DEG C, and no active metal elementary substance needs to be introduced in the preparation process.

The invention provides a preparation method of prismatic titanium diboride powder, and belongs to the technical field of titanium diboride powder. The preparation method comprises the steps of titanium source preparation, boron source preparation, material mixing, cold isostatic pressing and carbon thermal reduction reaction. The step of preparing the titanium source comprises the following steps: heating TiO2 powder body liquid, raising the temperature to 52-55 DEG C, adding a tetrabutyl titanate solution, uniformly stirring, adding an ammonia water solution to adjust the pH value to 7.0, and carrying out heat preservation stirring for 2.7-3.2 hours to obtain the titanium source; the step of preparing the boron source comprises the following steps: adding B4C powder into absolute ethyl alcohol, carrying out ultrasonic dispersion, then adding a mixed solution, controlling the adding rate of the mixed solution to be 0.8-1.2 g / min, heating to 34-37 DEG C, and carrying out heat preservation and stirring for 3.8-4.2 hours to obtain the boron source; the titanium diboride powder obtained through the method is in a prism shape and is uniform in particle, high in density and purity and poor in high-temperature oxidation resistance.

The invention discloses medium-entropy MAB-phase ceramic powder and a preparation method thereof, and belongs to the technical field of ceramic material preparation. The chemical formula of the ceramic powder is (Cr1 / 3Mn1 / 3Fe1 / 3) 2AlB2, and the ceramic powder is structurally characterized in that three transition metal atoms of Cr, Mn and Fe are in random solid solution distribution at an M position. The preparation method of the material comprises the following steps: taking Cr powder, Mn powder, Fe powder, Al powder and B powder as raw materials, burdening according to a stoichiometric molar ratio in a chemical formula (Cr1 / 3Mn1 / 3Fe1 / 3) 2AlxB2 (wherein x is equal to 1.0-1.3), uniformly mixing, and sintering in a non-pressure tube furnace by adopting a two-stage heating sintering process. And crushing, drying and sieving the sintered product to obtain the ceramic powder. According to the invention, excessive aluminum powder is added to compensate high-temperature volatilization, and a two-stage sintering process is combined, so that the generation of an impurity phase is effectively inhibited, and a high-purity target product is successfully prepared. The synthesis method is simple in process, low in equipment requirement and suitable for large-scale production, and a material basis is provided for application of the medium-entropy MAB phase ceramic in the fields of electromagnetic functions, high-temperature environments and the like.

The invention discloses a TiB2 / SiO2 composite material and a preparation method thereof, and relates to the technical field of new materials.The preparation method of the TiB2 / SiO2 composite material comprises the following steps that TiB2 is pretreated with a NaOH solution, then Na2SiO3. 9H2O and deionized water are mixed and then added into the pretreatment solution, the pH is adjusted to be 8.5, stirring is conducted for 2 h at the temperature of 85 DEG C, and the TiB2 / SiO2 composite material is obtained; and sequentially carrying out centrifugal filtration, washing and drying to obtain the product. The TiB2 / SiO2 powder product is prepared through a specific chemical solution process, the TiB2 / SiO2 powder product has excellent dielectric properties and can be used for manufacturing wave-absorbing materials and reducing reflection of electromagnetic waves, and TiB2 and SiO2 both have excellent oxidation resistance, so that the TiB2 / SiO2 powder product prepared through the method has greater application potential at high temperature.

The present invention provides: a MgB2 superconducting wire that has a barrier layer of highly uniform thickness covering a MgB2 core and that reduces MgB2 filament defects and is suitable for thinning and lengthening; a MgB2 superconducting wire manufacturing method for manufacturing the same; a superconducting coil using the same; and a magnetic generator including the superconducting coil. A MgB2 superconducting wire (200) comprises: a core material (210); a MgB2 filament (220) in which a MgB2 core (221) is covered with a barrier layer (222); and a metal sheath (230). The MgB2 filament (220) has a barrier layer (222) thickness on the outer peripheral side of the wire not more than three times the barrier layer (222) thickness on the core side of the wire. The method for manufacturing the MgB2 superconducting wire includes a step for forming a single core wire, a step for forming an embedded material, a surface reduction processing step, and a heat treatment step. The embedded material is formed by arranging the single core wire in a recess formed in the outer surface of the core material or by incorporating a spacer in a gap.

The invention relates to a method for fabricating a two-dimensional (2D) heterostructure comprising depositing graphene on a substrate in an ultrahigh vacuum (UHV) chamber at a first temperature and a first chamber pressure to form sub-monolayer graphene on the substrate; and subsequently depositing borophene onto the sub-monolayer graphene on the substrate in the UHV chamber at a second temperature and a second chamber pressure so as to couple the borophene with the graphene on the substrate to form a 2D borophene-graphene heterostructure comprising lateral and / or vertical heterostructures.

The invention provides high-purity superfine titanium diboride and a preparation method thereof, and relates to the field of titanium diboride preparation. The method comprises the following steps: mixing boron oxide, titanium hydride, a carbon source, nano rare earth oxide and an organic solvent, and drying to obtain a mixture; in a vacuum environment, performing first roasting on the mixture to obtain a first roasted material; and in an oxygen-containing atmosphere, carrying out second roasting on the first roasting material to obtain the high-purity superfine titanium diboride. In the first roasting process, boron oxide, titanium hydride and a carbon source are completely melted and fully contacted, then further, the carbon source forms a carbon skeleton, the contact area between the melted boron oxide and titanium hydride and the carbon skeleton is further enlarged, liquid-liquid mixing and the increase of the contact area can reduce the reaction kinetic conditions, the reaction temperature is greatly reduced, and the reaction time is greatly shortened. The particle size of the generated titanium diboride is reduced, and the molten boron oxide and titanium hydride react on the porous carbon skeleton in a liquid-liquid form to generate the high-purity superfine titanium diboride.

The invention discloses a lithium ion battery ultrahigh nickel positive electrode material and a preparation method and application thereof, and belongs to the technical field of lithium ion batteries. The ultrahigh nickel positive electrode material is formed by coating the surface of a boron-doped nickel cobalt lithium manganate positive electrode material with a hydrophobic transition metal diboride. The surface of the ultra-high nickel active material is coated with the thin and uniform transition metal diboride hydrophobic coating layer, transition metal diboride has high ionic conductivity, and the obtained lithium ion battery has good cycle performance; the transition metal diboride can ensure the hydrophobic property, so that the stability of the lithium ion battery in the environment is ensured; the surface transition metal diboride and internally doped boron ions are synergistically modified, so that the cycle performance, the rate capability and the safety performance of the material in battery application are remarkably improved.

The invention discloses a zirconium boride-carbon hybrid aerogel composite material and a preparation method thereof, and belongs to the technical field of aerogel materials. In order to solve the problem of insufficient oxidation resistance of a carbon aerogel material, a co-gel method is mainly adopted to introduce a zirconium boride precursor network, zirconium boride is generated in situ through pyrolysis reduction, and matrix oxidation resistance modification of carbon aerogel is realized. A stable anti-oxidation protection layer can be formed in a high-temperature aerobic environment, the high-temperature-resistant and anti-oxidation performance of the material is improved, and the material can be applied to the field of light thermal protection.

The invention belongs to the technical field of preparation of alkaline earth metal hexaboride powder, and provides a preparation method of strontium hexaboride nanopowder, which comprises the following steps: drying SrCl2. 6H2O powder to obtain SrCl2 powder; the preparation method comprises the following steps: grinding and mixing SrCl2 powder and NaBH4 powder to obtain mixed powder a; the mixed powder a and LiCl-KCl eutectic salt are mixed, and mixed powder b is obtained; performing high-temperature reaction on the mixed powder b to obtain mixed powder c; and dissolving the mixed powder c in water, and sequentially filtering, drying, pickling and washing to obtain the strontium hexaboride nano powder. The average particle size of the prepared nano powder is 30-80 nm, and the nano powder has good cubic morphology, has the characteristics of high surface activity, large specific area and the like, and has wide application prospects as multifunctional ceramic powder. Meanwhile, the preparation cost can be effectively reduced, and a new thought for preparing the SrB6 powder is provided.

To provide a superconducting material that can be used for a liquid hydrogen level meter and that offers a simple manufacturing process and has reproducibility.SOLUTION: The superconductor comprises a metal compound having a molar ratio of magnesium (Mg) and boron (B) of 1:2, does not contain SiC, and has a critical temperature (Tc) of about 32 K to about 34 K at which electrical resistance becomes substantially zero. Thus, a liquid hydrogen level meter that offers a simple manufacturing process and has reproducibility can be realized.SELECTED DRAWING: Figure 1

Provided are methods of producing cobalt-based nanoparticles (CoxBy NPs) of a pre-selected diameter. The methods include reducing Co2+ ions with a sodium borohydride (NaBH4) solution having a selected ratio of tetrahydroxyborate (B(OH)4−) to tetrahydroborate (BH4−) based on the pre-selected diameter, where the ratio of B(OH)4− to BH4− is positively correlated with the pre-selected diameter. Also provided are methods of using the CoxBy NPs to produce hollow metal nanospheres (HMNs). Methods of producing CoxBy NP core / metal shell structures are also provided, such methods including combining in an anaerobic galvanic exchange reaction a deaerated solution including CoxBy NP scaffolds and a deaerated solution including a metal. Also provided are methods of producing HMNs from the CoxBy NP core / metal shell structures. Compositions and kits that find use in practicing the methods of the present disclosure and using HMNs produced in accordance with the methods of the present disclosure, are also provided.

The invention belongs to the technical field of preparation of high-purity cobalt boride, and particularly provides a preparation method of high-purity superfine cobalt boride powder, which comprises the following steps: 1) mixing Co3O4 with isopropanol, sanding and crushing to obtain Co3O4 slurry; b4C and isopropanol are mixed, sanded and crushed to obtain B4C slurry; then mixing the Co3O4 slurry with the B4C slurry and carbon black at a high speed to obtain a mixture; 2) sintering the mixture under the protection of inert gas to obtain a sintered material, and 3) scattering and sieving the sintered material to obtain the CoB. The CoB prepared by the invention has the advantages of low impurity content, small particle size and uniformity.

The invention discloses a diboride hollow microsphere and a preparation method thereof, and belongs to the technical field of new material preparation. The invention aims to solve the problem of preparing diboride hollow microspheres with excellent performance. The preparation method comprises the following steps: preparing precursor sol; performing gelatinization treatment on the precursor sol in a high-temperature closed environment, performing normal-pressure drying in an open environment to obtain a diboride hollow microsphere precursor, grinding the diboride hollow microsphere precursor into powder in a crucible, then performing secondary grinding in an aqueous solution containing PEG-4000, performing ultrasonic treatment after uniform grinding, and then performing vacuum drying to obtain the diboride hollow microsphere. And carrying out high-temperature boron-carbon thermal reduction reaction on the obtained diboride hollow microsphere precursor to generate diboride hollow microspheres, and carrying out solution treatment on the diboride hollow microspheres under a high-temperature condition to obtain a final product. The preparation of the high-quality diboride hollow microspheres is realized, the high-quality diboride hollow microspheres have good dispersity, and the product forming rate can reach 80% or above.

The invention belongs to the technical field of photocatalyst composite materials, and particularly relates to a covalent bond bonded MoBTx / CdS composite material and a preparation method and application thereof.According to the MoBTx / CdS composite material, rod-shaped CdS and two-dimensional layered MoBTx are compounded through an in-situ growth strategy, covalent bonding between Mo atoms and S atoms is achieved at an interface, and the MoBTx / CdS composite material is obtained. Therefore, a strong-coupling heterogeneous interface is constructed. The covalent bond mediated composite structure can significantly enhance visible light absorption and optimize carrier separation and transmission kinetics, thereby improving the activity and stability of hydrogen production by photocatalytic decomposition of water. The material is excellent in environmental adaptability and can keep good hydrogen evolution performance under complex water quality and low-temperature conditions. The research provides a new interface engineering idea for designing an efficient and stable semiconductor-metal boride photocatalyst.

Provided is a method for preparing zirconium boride through electric smelting. The method includes: mixing a zirconium source, boric anhydride, and a carbon source to obtain a furnace charge; conducting a smelting by feeding the furnace charge into a three-phase electric arc furnace and melting, subjecting a resulting material to refinement, heat preservation, and homogenization in sequence; heat preserving a resulting product for 1 hour to 2 hours after the smelting, and turning off the three-phase electric arc furnace; removing a resulting furnace shell and natural cooling a resulting melt; and crushing the resulting melt, selecting and removing a material skin; crushing a resulting selected material and selecting again, and removing a loose lump and collecting a dense lumpy material; and crushing the dense lumpy material, and then testing to qualify as a finished product.

The present invention relates to a method for dissolving atoms in a metal, and provides a method for easily dissolving atoms in a metal having low solubility for the atoms by using, as a mediator, a metal which has high solubility for the atoms. Thus, elements such as carbon (C), boron (B), and nitrogen (N) can be stably introduced into metals in which these elements cannot be dissolved by using existing techniques or have very low solubility, thereby enabling the synthesis of new compounds and doped metals or alloys, resulting in improved physical properties of a metal, for example, properties such as strength, corrosion resistance, and conductivity.

The present disclosure relates to a boron powder having two or more peaks in a number distribution, and a peak frequency of a peak 2 having the second highest frequency relative to a peak frequency of a peak 1 having the highest frequency is more than 0.12. It is preferable that the peak diameter of the peak 1 is smaller than the peak diameter of the peak 2.

The invention relates to a lithium-rich manganese-based positive electrode material, a preparation method thereof and a lithium ion battery. The lithium-rich manganese-based positive electrode material comprises a cerium-doped lithium-rich manganese-based positive electrode material core and a coating layer, the coating layer comprises a cobalt boride coating layer and a carbon coating layer which are stacked in sequence, and the cobalt boride coating layer is located on the surface of the cerium-doped lithium-rich manganese-based positive electrode material core. The core of the lithium-rich manganese-based positive electrode material is doped with the cerium element, the crystal structure of the lithium-rich manganese-based positive electrode material can be effectively stabilized, the electronic conductivity and the ion diffusion rate of the material can be improved, meanwhile, the cobalt boride layer and the carbon layer on the surface act synergistically, the lithium-rich manganese-based positive electrode material is coated in all directions, and the lithium-rich manganese-based positive electrode material can be applied to the lithium-rich manganese-based positive electrode material. And doping and coating are adopted for modification at the same time, so that the chemical stability and the electrochemical performance of the lithium-rich manganese-based positive electrode material can be effectively improved.

The application provides a preparation method of high-purity superfine diboride powder and relates to the field of metal borides. The preparation method comprises the following steps: introducing BCl3 and H2 into a vacuum environment to obtain a mixed gas; mixing the mixed gas and metal wires and performing electric explosion treatment to obtain a reaction powder; and performing passivation ball milling treatment on the reaction powder in a mixed atmosphere of argon and oxygen to obtain the high-purity superfine diboride powder; and the metal wires comprise at least one of titanium wires, magnesium wires and aluminum wires. The method does not introduce by-products and impurities in the whole process, the obtained diboride powder is small in particle size, uniform in distribution and free of agglomeration, the preparation method is short in process and high in efficiency, and the method has a good industrialization prospect.

The invention relates to a method for synthesizing calcium hexaboride micro-nano powder by electric field and magnetic field coupling auxiliary combustion, which mainly comprises the following steps: by taking calcium hydroxide, boric oxide and magnesium powder as raw materials, carrying out electric field and magnetic field coupling auxiliary combustion synthesis to obtain a reaction product; and then, carrying out acid pickling on a reaction product to obtain the unique calcium hexaboride micro-nano material with the hollow cubic structure. In the process of combustion synthesis of calcium hexaboride, under the coupling influence of an electric field and a magnetic field, the prepared calcium hexaboride micro-nano powder shows unique hollow cubic structural characteristics, and the structural characteristics enable the calcium hexaboride micro-nano powder to have the advantages of high specific surface area, light weight, porous neutron absorption and the like; the method has important application prospects in the fields of aerospace, high-end manufacturing, nuclear industry and the like.

The present invention discloses a tungsten boride with high fluidity and a pure phase thereof and a preparation method thereof. The method includes: (1) mixing tungsten powder, boron powder and grinding balls for ball milling to obtain a tungsten-boron mixed powder; (2) under an inert atmosphere, subjecting the tungsten-boron mixed powder to pressure sintering to obtain a pure-phase tungsten boride powder; (3) self-mixing the pure-phase tungsten boride powder; (4) screening the self-mixed tungsten boride powder to obtain a tungsten boride with high fluidity and a pure phase. The tungsten boride prepared by this method has a single phase and no other impurity phases, and at the same time has high fluidity.

The present invention provides a BN-Mo2B high-temperature wear-resistant material and a preparation process thereof, and relates to the technical field of high-temperature wear-resistant materials. The preparation process of the BN-Mo2B high-temperature wear-resistant material comprises the following steps: first mixed ball milling: weighing Mo powder and B powder according to a molar ratio of a:b and loading them into a ball mill for ball milling for 5 to 20 hours to obtain a first mixed powder, wherein a is 2 and b is in the range of 1 to 1.6; second mixed ball milling: loading BN powder at a temperature of 80 to 100°C and the first mixed powder into a ball mill for ball milling for 10 to 30 hours to obtain a second mixed powder, wherein the weight of the BN powder is 5% to 20% of the weight of the first mixed powder; sintering: placing the second mixed powder cooled to room temperature in a plasma activated sintering furnace for sintering, and keeping the temperature at a sintering temperature of 1000 to 1400°C and a pressure of 300 to 500 MPa for 0.5 to 3 hours to finally obtain the BN-Mo2B material. The BN-Mo2B material produced by this preparation process has low cost and excellent high-temperature wear resistance.

The invention relates to the technical field of electrochemical energy storage, in particular to a Li / Na ion battery negative electrode material heterojunction as well as a construction method and a performance prediction method thereof, the negative electrode material is a two-dimensional MoB / MoS2 Van der Waals heterojunction, and is formed by compounding MoB with high conductivity and MoS2 with high theoretical capacity. A built-in electric field induced by a work function difference exists at an interface of the heterojunction, so that electron transmission and ion migration can be remarkably accelerated; meanwhile, volume change in the charging and discharging process is effectively buffered through tight interface coupling and B-S covalent interaction, and the structural stability is enhanced. Through systematic evaluation of a first principle calculation method, the MoB / MoS2 heterojunction shows high theoretical specific capacity, low ion diffusion barrier, appropriate open-circuit voltage and excellent structural and mechanical stability, and is a high-performance Li / Na ion battery negative electrode material with great potential.

The application is a preparation method and application of ternary metal boride MoCoB electrocatalyst. 2 / 3 Y 1 / 3 )2AlB2 as a precursor, cobalt bromide as an etchant and a cobalt source, one-step removal of Al / Y and in-situ doping of Co to prepare MoCoB electrocatalyst with Mo / Co / B three-site synergy; Mo site efficiently adsorbs and activates nitrate, Co site dissociates water to provide active hydrogen, and B site builds an electronic bridge through orbital hybridization, thereby strengthening the electron transfer between active sites and the directional migration of active hydrogen. The electrocatalyst prepared by the application shows a faradaic efficiency of up to 61890 μg h ‑1 mg ‑1 and 98.73% in the reaction of nitrate reduction to synthesize ammonia, not only realizing high yield and high faradaic efficiency at the same time, but also showing the industrial application potential of green and sustainable synthesis of ammonia.

This application relates to a composite positive electrode active material for a lithium secondary battery. The composite positive electrode active material includes a nickel-based active material and a cobalt-boron compound-containing coating layer formed on a surface of the nickel-based active material. The application also relates to a method of preparation of the composite positive electrode active material. The application further relates to a lithium secondary battery including a positive electrode containing the composite positive electrode active material.

The application discloses a kind of powder preparation devices of titanium diboride for lithium battery preparation, including preparation container, controller, gas pressure gauge and servo motor, the output end of the servo motor passes through preparation container and is fixedly connected with ball screw nut pair, kettle wall contact component is arranged outside the ball screw nut pair, specifically relates to titanium diboride powder preparation technical field, the dispersion component rotation is realized when screw shaft axial rotation and is driven to realize the dispersion stirring operation of kettle body bottom material, the preparation rate of material can be promoted by dispersion component rotation and drives material stirring, and the purpose of kettle body wall scanning and dispersion component dispersion material can be completed under the premise that only one servo motor works, so that the purpose of promoting material preparation rate and reducing material loss can be simultaneously realized in energy-saving environment, effectively realize the purpose of reducing cost and improving yield and product quality.

The invention relates to the technical field of preparation of negative electrode materials for lithium ion batteries, and in particular to a defective h-MAB phase titanium indium boron negative electrode material, a preparation method thereof and an application thereof in lithium ion batteries. The invention uses titanium powder, indium powder and boron powder as raw materials to prepare a Ti2InB2 material, then puts the obtained Ti2InB2 material into a ball mill for ball milling, and then performs simple acid washing and impurity removal to obtain the defective h-MAB phase titanium indium boron negative electrode material. The invention adopts a simple ball milling operation to manufacture defects on the Ti2InB2 material, and overcomes the shortcomings of the defect introduction method in the prior art and the technical defects of poor electrochemical performance of the Ti2InB2 material. The obtained defective h-MAB phase titanium indium boron negative electrode material has a hexagonal system and a layered microstructure, the layers are connected by chemical bonds, and a graphene-like boron layer is provided. The special crystal structure enables the h-MAB phase to have novel physical properties, and is suitable for being used as an electrode material.