416results about "From solid state" patented technology

The invention relates to a nano silicon carbide whisker and a preparation method thereof, and the preparation method comprises the following steps: (1) carrying out acid process treatment on fly ash by using an acid solution, so that the content of key impurity elements in the fly ash accounts for 2-11% of the total mass of the treated fly ash, and obtaining acid-treated fly ash; (2) mixing the acid-treated fly ash with a first carbon source to obtain a mixture; and (3) covering the mixture with a second carbon source, roasting in a reducing atmosphere to obtain a roasted material which comprises a nano silicon carbide whisker layer and a total impurity layer positioned below the silicon carbide whisker layer, and removing the total impurity layer to obtain the nano silicon carbide whisker. According to the preparation method, the low-cost fly ash is taken as a raw material, the advantages of low preparation cost and relatively high product yield can be taken into account through the synergistic effect of moderate acid treatment, raw material position setting and roasting in the reducing atmosphere, and good morphology and relatively high purity of the nano silicon carbide crystal whiskers are ensured.

The invention discloses a preparation method of a perovskite thin film and a perovskite cell, and relates to the technical field of solar cells. The preparation method of the perovskite thin film comprises the following steps: forming a mixed layer containing PbI2 on a substrate as a metal halide framework layer; coating the metal halide framework layer with an organic ammonium salt solution containing a crystallization regulating agent to obtain a first device; wherein the crystallization regulating agent contains a guanidine group; and carrying out annealing treatment on the first device to obtain the perovskite thin film. According to the perovskite thin film, the problems that perovskite prepared in the prior art is small in grain size and uneven in interface can be solved, and the performance of the perovskite thin film is improved.

The invention belongs to the technical field of lithium ion battery materials, and discloses a preparation method of a high-first-effect small-particle single-crystal ultrahigh-nickel ternary positive electrode material. The method comprises the following steps: firstly, uniformly mixing an ultrahigh nickel ternary precursor with a lithium source and a tungsten source, performing mechanical densification and pressing to obtain a blocky solid, and then performing four-section program temperature control calcination to obtain a target material. The interface fusion resistance of single crystal growth can be reduced through mechanical densification; a part of the tungsten element forms a Li2WO4 coating layer, and a part of the dopant phase replaces Ni < 2 + >, so that grain growth can be inhibited, a crystal structure can be stabilized, and the first effect is improved; and the microstructure of the material can be accurately regulated and controlled through four-section temperature-controlled calcination. Through a coating-doping-single crystallization synergistic strategy, the electrochemical performance of the material in liquid and sulfide-based all-solid-state batteries is remarkably improved, the process is controllable, and the application prospect is wide.

The invention discloses a high-voltage single-crystal positive electrode material as well as a preparation method and application thereof, and belongs to the technical field of lithium ion batteries. The preparation method comprises the following steps: by taking MOFs (Metal Organic Frameworks) with a porous structure as a template, loading a ternary precursor in pore channels of the template by adopting a solvothermal method to prepare loaded MOFs; mixing the loaded MOFs with a lithium source, carbonizing and calcining in an inert atmosphere for high-temperature solid-phase reaction, carbonizing the template to form a nitrogen-doped porous carbon skeleton, and converting the ternary precursor into single-crystal NCM particles to prepare a calcined product; sequentially carrying out acid pickling, drying and airflow crushing treatment on the calcined product to obtain a composite material; the composite material is sequentially subjected to multi-section penetration type dry coating and sintering treatment, the high-voltage single-crystal positive electrode material is prepared, and the high-voltage single-crystal positive electrode material can balance the capacity, the cycle life and the safety under high voltage.

The present description belongs to the technical field of battery materials. Disclosed are a single-crystal ternary positive electrode material, a preparation method therefor, a positive electrode sheet and a battery. The apparent factor of the single-crystal ternary positive electrode material is [Formula 1], wherein 1.1≤Z≤3, x=D90 / D10, 2≤x≤5; S(D90) is the number averaged circularity, the total number of target particles is n, and the number averaged circularity is defined as the sum of circularity values of all of the target particles divided by n. The area and circumference corresponding to a two-dimensional projection image of a single target particle are respectively S1 and l1, the circumference of a circle having the area S1 is l2}, and the circularity = l2 / l1. The D10' is the corresponding particle size of a material obtained by compacting the single-crystal ternary positive electrode material at 200 MPa, D10 does not exceed 2.4 μm, and D10' does not exceed 2.3 μm. The single-crystal ternary positive electrode material has smooth surfaces and rounded edges, which are beneficial for fabricating batteries having excellent electrochemical properties.

The invention relates to a method for preparing a single-crystal lithium-rich manganese-based positive electrode material by synergistically regulating and controlling a deep eutectic solvent and aluminum gradient doping, which comprises the following steps of: carrying out multi-stage aluminum gradient doping to prepare a single-crystal lithium-rich manganese-based positive electrode material by synergistically regulating and controlling the deep eutectic solvent and the aluminum gradient doping; multi-level regulation and control on the structure of the positive electrode material from the inside to the surface are realized; the formation of an inducible single-crystal structure is assisted by the deep eutectic solvent; through addition of phosphorus / boron-containing anions and microwave strengthening treatment, oxygen vacancy lattice repair is promoted; carbon in-situ coating treatment is realized by adding a carbon source, so that the conductivity and interface stability of the material are improved; and lithium defects caused by other steps can be compensated through pre-lithiation treatment, and the first coulombic efficiency is improved. And five parts are integrated, so that the structural stability, the electrochemical performance and the safety of the material are multiply improved.

The invention provides a single-crystal cobalt-free lithium-rich manganese-based positive electrode material as well as a preparation method and application thereof. The preparation method comprises the following steps: mixing a cobalt-free lithium-rich manganese-based precursor material, a lithium source and a grain boundary separation auxiliary agent to obtain a mixed material; the mixed material is subjected to two-stage sintering, the two-stage sintering comprises first sintering and second sintering in sequence, and the single-crystal cobalt-free lithium-rich manganese-based positive electrode material is obtained, wherein primary crystal grains of the cobalt-free lithium-rich manganese-based precursor material are of a sheet structure. According to the invention, the cobalt-free lithium-rich manganese-based precursor material of which the primary crystal grains are of a sheet structure is taken as a raw material, and under the action of the grain boundary separation auxiliary agent, a two-stage sintering process is cooperatively matched, so that the single-crystal cobalt-free lithium-rich manganese-based positive electrode material which is uniform in grain size, high in dispersity, complete in crystal grains and continuous in interface is obtained, and the cobalt-free lithium-rich manganese-based positive electrode material is not only suitable for a liquid lithium ion battery, but also suitable for a lithium ion battery. The material is more suitable for a solid-state lithium ion battery, and the electrochemical performance of the battery is effectively improved.

The invention discloses a method for directly regenerating a failed battery positive electrode material into a single-crystal high-voltage positive electrode based on size regulation and application. The method comprises the following steps: mixing the polycrystalline NCM positive electrode material of the failed battery with low-melting-point molten salt, performing low-temperature pre-sintering lithium supplementation, and performing high-temperature annealing to realize grain size regulation and structure optimization, thereby finally obtaining the high-voltage positive electrode material with a single-crystal structure. The method is short in technological process, low in energy consumption and small in environmental pollution, the regenerated positive electrode material has excellent electrochemical performance and is suitable for a high-voltage (larger than or equal to 4.4 V) lithium ion battery, and efficient and high-added-value recycling of the failed battery positive electrode material is achieved.

The invention discloses a preparation method of high-purity aluminum nitride single crystal powder. The method comprises the following steps: uniformly mixing raw materials aluminum powder and aluminum nitride powder according to a ratio, putting the mixture into an air pressure sintering furnace, vacuumizing, introducing high-pressure argon, heating to a set temperature, introducing nitrogen, carrying out a fire blast reaction, cooling to room temperature, and crushing to obtain the high-purity aluminum nitride single crystal powder with D50 of 20-200 microns. According to the method, the synthesis of the coarse-particle high-purity aluminum nitride single crystal powder is realized by utilizing the rapid nitridation explosion reaction of the aluminum powder in the high-temperature and high-pressure nitrogen, the method has the characteristics of simple process and low preparation cost, and the prepared high-purity aluminum nitride single crystal powder can be used as a high-thermal-conductivity filler for electronic packaging.

The invention discloses a multi-element differentiated distribution co-doped single-crystal high-nickel positive electrode material and a preparation method and application thereof.The material is doped with a first doping element and a second doping element, the first doping element is in gradient distribution with the concentration gradually increased from inside to outside in material particles, and the second doping element is in gradient distribution with the concentration gradually increased from inside to outside. The second doping elements are basically and uniformly distributed in the material particles; the first doping element is used for strengthening the surface stability of the material, and the second doping element is used for stabilizing the bulk phase structure of the material. The material is obtained by taking a lithium salt and a ternary positive electrode material precursor as raw materials, introducing a first doping source and a second doping source, mixing, ball-milling and calcining according to a preset stoichiometric ratio.

The application belongs to the field of lithium ion battery cathode material preparation, and particularly relates to a high-voltage type single-crystal lithium manganate, a preparation method and application thereof. The scheme mixes a manganese source compound, a lithium source compound and a transition metal oxide according to a molar ratio of 1:0.5-0.6:0.1-0.3, deoxidizes and sinter, to obtain a single-crystal lithium manganate intermediate product; the obtained intermediate product is used as a raw material to prepare a finished product; the deoxidizing and sintering operation is to raise the temperature from room temperature to 800-1000 DEG C at a temperature raising rate of 20-30 DEG C / min, and keep constant temperature for 2-6 h, no temperature keeping operation is performed in the temperature raising process, after the constant temperature stage is finished, the temperature is lowered to 400-500 DEG C at a temperature lowering rate of 50-100 DEG C / h, and keep constant temperature for 2-4 h, to prepare the high-voltage type single-crystal lithium manganate cathode material. The scheme can significantly improve the capacity and high-temperature cycle performance of the lithium manganate material, and inhibit the battery expansion rate, through fast temperature raising, gradient temperature lowering and the cooperation of radius-matched doping elements. Meanwhile, the application also provides application of the high-voltage type single-crystal lithium manganate cathode material in a battery.

This invention belongs to the field of single-crystal material preparation technology, specifically relating to a molybdenum trioxide single-crystal ribbon and its preparation method. During the calcination of a molybdenum source, the ribbon is contacted with a structure-directing agent composed of alkali metal salts and metals other than molybdenum in Group 6, or alkaline earth metal salts and metals other than molybdenum in Group 6. After cooling, the molybdenum trioxide single-crystal ribbon is obtained. This invention does not require complex template guidance, the structure-directing agent is simple and readily available, and it enables molybdenum trioxide crystals to grow along a specific direction, resulting in a highly crystalline molybdenum trioxide single-crystal ribbon.

The invention provides a perovskite pseudo-single crystal thin film and a preparation method thereof. The preparation method comprises the following steps: (1) preparing a perovskite polycrystalline thin film on a hydrophilic substrate; (2) pressing a hydrophobic substrate on the perovskite polycrystalline thin film to obtain a sandwich structure; (3) performing hot-pressing annealing treatment on the sandwich structure; and (4) after hot-pressing annealing treatment, removing the hydrophilic substrate and the hydrophobic substrate to obtain the perovskite pseudo-single crystal film. On the basis of the hot pressing technology, full diffusion, dissolution and recrystallization of crystal grains are promoted, the perovskite quasi-single crystal thin film with large crystal grains, low defects and high orientation is formed, and the method is suitable for various perovskite materials, simple in process, good in repeatability and capable of meeting the actual requirements of novel photoelectric devices.

The invention relates to a biphase P2-O3 type single crystal sodium ion layered oxide positive electrode material and a preparation method and application thereof, the biphase P2-O3 type single crystal sodium ion layered oxide positive electrode material is of a core-shell structure, the core is P2 phase sodium ion layered oxide, and the shell is O3 phase sodium ion layered oxide. According to the invention, the O3 phase is generated in situ on the surface of the P2-phase particle in a mode of supplementing the sodium source and carrying out high-temperature secondary sintering, and the formed composite-phase single crystal particle is of a special double-phase structure with a core P2 phase, so that the specific capacity, the structural stability and the cycle performance of the material are improved, and the problem of insufficient performance of a double-phase layered oxide positive electrode material in the prior art is solved.

The invention relates to the technical field of preparation of single crystal materials, in particular to a low-cost lead-free piezoelectric single crystal with high piezoelectric response and a preparation method, the lead-free piezoelectric single crystal is of a lead-free perovskite structure, the chemical general formula of the lead-free piezoelectric single crystal is xBi < 0.5 > Na < 0.5 > TiO < 3-y > Bi < 0.5 > K < 0.5 > TiO < 3-(1-x-y) Bi < 0.5 > Li < 0.5 > TiO < 3 >, x is equal to 0-1, y is equal to 0-0.2, and x is equal to 0-1. The preparation method comprises synthesis of a multi-component lead-free precursor polycrystalline material, interface construction of a seed crystal and a polycrystalline substrate, and a high-temperature solid-phase epitaxial growth process. The components and various key process parameters of the material involved in the invention are finely controlled, the process window in the preparation process is narrow, reverse analysis is not easy to occur, and the preparation method has a remarkable technical barrier and is suitable for industrial popularization as a key preparation technology of the high-performance lead-free piezoelectric single crystal material.

The application discloses a synthesis method of a large single-crystal sodium-ion battery layered oxide positive electrode material, and comprises the following steps: (1) weighing metal oxides containing transition metal elements, transferring to a device with mixing functions, uniformly mixing, and obtaining a metal oxide mixture; (2) adding acid to the metal oxide mixture, fully mixing, and completing an acid treatment process; (3) adding alkali to the mixture after acid treatment, fully mixing; (4) transferring the mixture obtained in the step (3) to a calcining furnace, high-temperature calcining, and obtaining a layered oxide. The acid treatment process is introduced, the surface of the metal oxide forms a defect structure under the action of the acid, and the defect structure is more beneficial to the formation of strong interaction between each component of the metal oxide and between the metal oxide and sodium-containing alkali, so that a larger single-crystal layered oxide structure is finally formed, and the specific capacity, rate performance and cycle performance are excellent.

The application discloses a preparation method of vanadium-doped and high-hydrated mangan-chromian spinel monocrystal under high temperature and high pressure. The cylindrical mangan-chromian spinel sample is prepared by taking solid rose triangular rhombic manganese carbonate crystal, solid chromium (III) acetate hydroxide crystalline powder, solid vanadium (IV) acetylacetonate oxide powder, solid oxalic acid powder, solid bixbyite powder, solid chromium hydroxide powder and liquid dilute nitric acid as starting raw materials; two pieces of water source sheets are made from the bixbyite powder and the chromium hydroxide powder with a weight ratio of 4:1; the two pieces of water source sheets are placed at two ends of the cylindrical mangan-chromian spinel sample and then are placed into a double-capsule structure experimental sample bin with an inner layer sleeve being a graphite tube and an outer layer sleeve being a gold-palladium alloy tube; the high temperature and high pressure reaction is carried out to obtain the mangan-chromian spinel monocrystal; and the preparation technology blank of the vanadium-doped and high-hydrated mangan-chromian spinel large-particle monocrystal under the current high temperature and high pressure conditions is solved.

The invention provides a single-crystal positive electrode material as well as a preparation method and application thereof. The molecular formula of the single-crystal positive electrode material is shown as a formula 1; lia2Nib2Coc2Mnd2Me2SgO2 is shown as a formula 1 in the specification; in the formula 1, M comprises M1 and M2, 0.95 < = a2 < = 1.05, 0.8 < = b2 < = 0.1, 0.01 < = c1 < = 0.15, 0.01 < = d1 < = 0.15, 0.0002 < = e2 < = 0.02, and 0.0001 < = g < = 0.01; m1 includes at least one of Zr, La, Ti, W, Mo, Sr, Ce, Y, Mg, Te, Nb, and Ta; m2 includes at least one of Co, Mg, Te, Sr, Al, Zr, and Nb. The single-crystal positive electrode material can improve the cycle performance of the battery.

The application discloses a preparation method of a nickel-doped and high-hydrated cobalt-chromium-iron ore monocrystal under high temperature and high pressure, and the method comprises the following steps: preparing a cylindrical cobalt-chromium-iron ore sample by taking solid basic cobalt carbonate powder, solid chromium (III) acetate hydroxide crystal powder, solid nickel stearate, solid oxalic acid powder, solid chromium hydroxide powder, solid nickel hydroxide powder and liquid dilute nitric acid as starting raw materials; preparing water source sheets by taking chromium hydroxide powder and nickel hydroxide powder in a weight ratio of 4:1; placing two water source sheets at two ends of the cylindrical cobalt-chromium-iron ore sample respectively and then putting them into a double-capsule structure sample bin; and obtaining a cobalt-chromium-iron ore monocrystal after high-temperature and high-pressure reaction, so that the blank of the preparation technology of the nickel-doped and high-hydrated cobalt-chromium-iron ore large-grain monocrystal under the current high-temperature and high-pressure condition is solved, and the experimental sample of the nickel-doped and high-hydrated cobalt-chromium-iron ore large-grain monocrystal is obtained.

The invention relates to a method for producing a perovskite-type single crystal, and a perovskite-type single crystal. Provided are: a single crystal which exhibits a high electromechanical coupling coefficient and a high coercive field when used in a piezoelectric element; and a method for producing the single crystal. The method is a method for producing a perovskite-type single crystal, in which a first single crystal of a perovskite type is prepared by firing a raw material containing an acceptor in an air atmosphere, a step (2) including firing the first single crystal in a reducing atmosphere, and a step (3) including firing the single crystal prepared in step (2) in an air atmosphere, in this order, a perovskite-type single crystal having a higher coercive field value than a first single crystal is prepared.

The application discloses a method for preparing a ferroelectric crystal optical superlattice by using a pyroelectric effect, a superlattice and application, and belongs to the field of electronic and optical devices. The method comprises the following steps: preparing a ferroelectric crystal material carrying an electrode pattern; heating the ferroelectric crystal material carrying the electrode pattern, and the heating temperature is 50-200 DEG C; in the temperature range, the ferroelectric crystal material carrying the electrode pattern is excited in the reverse direction of polarization by using the pyroelectric property of the ferroelectric crystal material itself; then, an annealing step is performed, and the annealing rate is 50-150 DEG C / h; after 1-10 times of heating and annealing cycles, the superlattice is obtained. The application breaks through the limitation of the external electric field polarization method for different electrode structures by creating a new polarization process, realizes the preparation of different superlattice crystals based on various structure electrodes, and further expands the application scenarios and application fields of the ferroelectric crystal material.

Low temperature synthesis, growth and doping methods and resulting materials are disclosed. According to an aspect, a method for material transformation includes providing a target material comprising carbon and / or hydrocarbon. The method also includes placing the target material within a fluid comprising a hydrogen source. Further, the method includes applying energy to the target material such that at least some of the target material is transformed to the same material with new beneficial bonding configuration.

The application discloses a method for precisely modulating microstructure of a silicon-rich silicon oxide film and a product prepared by the method. x The method comprises the following step S20: in-situ heating SiO x Film samples, and the electron beam generated by the transmission electron microscope is irradiated on the SiO x Film samples, so as to realize the thermal annealing treatment of the SiO x Film. The method promotes the process of decomposing the SiO x Film into nanometer silicon crystals and silicon dioxide by means of heating combined with electron beam irradiation, the processing area can be precisely controlled to the nanometer level, rapid thermal annealing is realized, and damage caused by the thermal annealing to the SiO

The application discloses a preparation method of an environment-friendly heat-insulating and heat-preserving coating, and the specific steps of the method are as follows: 1) preparing potassium hexatitanate whiskers through a droplet template technology: dissolving oxalic acid in deionized water to obtain A; adding titanium salt and potassium salt into A and stirring to obtain B; adding B into polyvinylpyrrolidone, ethylene glycol and tetrahydrofuran, stirring and aging to obtain a uniform film; heating under the condition of nitrogen to obtain single-crystal potassium hexatitanate; placing the single-crystal potassium hexatitanate in an alumina crucible, heating, quenching between two thick copper plates and cooling in liquid nitrogen; passing oxygen through the sample to obtain potassium hexatitanate whiskers through annealing; 2) preparing the environment-friendly heat-insulating and heat-preserving coating: mixing water, a dispersing agent, a wetting agent, ethylene glycol and a defoaming agent, adding hydroxyethyl cellulose and a pH regulator, further adding potassium hexatitanate whiskers and nano-silica aerogel and dispersing, and sequentially adding a water-based high-elastic emulsion, a water-based silicone-acrylate emulsion, a film-forming aid, a flame retardant, micrometer hollow glass microbeads, a bactericide and a near-infrared reflective material and stirring uniformly.

The invention discloses a two-dimensional polycrystalline selenium nanosheet and a preparation method and application thereof.The nanosheet is prepared by processing selenium nanoparticles through a hot-pressing method, the nanosheet is structurally characterized in that triangular crystal phase selenium and orthorhombic crystal phase selenium coexist, and the orthorhombic crystal phase is concentrated in the center and rich in point defects; the nanosheet can generate a plurality of ultra-narrow linewidth photoluminescence peaks from visible light to near-infrared band at room temperature, and the minimum full width at half maximum can reach 387 + / -90 [mu] eV. According to the method, local phase change is induced through thermal stress under the limitation of the substrate in the hot pressing process, and controllable construction of a polycrystalline structure is achieved. The obtained polycrystalline selenium nanosheet can be used as a high-color-purity luminescent material, is used for preparing an ultra-narrow linewidth photoelectric emitter working at room temperature, and has a wide application prospect in the fields of quantum photonics, high-resolution imaging, spectral analysis and the like.

The present application relates to a cathode material precursor, a single-crystal cathode material and a preparation method thereof, and a lithium ion battery. A general chemical formula of the single-crystal cathode material is LixNiaCobMncNdO2, where 0.98≤x≤1.1, 0.50≤a≤0.98, 0< b≤0.20, 0<c≤0.30,0≤d≤0.10, a+b+c+d=1, and N includes at least one of Al, Ti, Zr, Mg, Sr, Ba, Ca, Nb, W, Sb, Ta, Sn, or Y; a standard deviation of a mass content of each element of Ni, Co, and Mn in the single-crystal cathode material is ≤0.03; and lattice strain is ε<0.2%. According to the single-crystal cathode material provided in the present application, the lattice strain is low, diffusion energy barriers of lithium ions among crystallite can be reduced, such that a material shows low DCR and good rate performance; and generation of microcracks can also be inhibited, thereby improving the cycling performance of the material.

This invention discloses a method for preparing NaCrO2 single-crystal cathode material, belonging to the field of cathode material preparation technology. This invention proposes a novel method for preparing single-crystal cathode materials for high-performance sodium-ion batteries. First, large-size single-crystal Cr2O3 (1-30 μm) is used as raw material, mixed with a sodium source, and then subjected to a one-step high-temperature calcination to obtain NaCrO2 single-crystal cathode material. Furthermore, the NaCrO2 single-crystal cathode material prepared using this method has fewer single-crystal structural defects and exhibits a better long-range ordered layered structure.

The present invention relates to a single-crystalline Al2O3 dielectric compatible with two-dimensional materials and an integrated device thereof. A single-crystalline Al thin film is produced on a single-crystalline graphene / germanium (110) substrate via the van der Waals (vdW) epitaxy approach, the single-crystalline Al thin film is peeled off from the graphene / germanium substrate, and intercalative oxidation is performed to produce the single-crystalline Al2O3 dielectric compatible with two-dimensional materials on the lower surface of the single-crystalline Al thin film. The gate leakage current (J<1×10−5 A cm−2), interface state density (Dit=8.4×109 cm−2 eV−1), and dielectric strength (Ebd=17.4 MV / cm) of the single-crystalline Al2O3 dielectric obtained in the present invention can meet the requirements of the international roadmap for devices and systems (IRDS) for low power consumption devices.

This invention discloses a sheet-like porous cobalt chloride, a single-crystal cobalt tetroxide, a single-crystal lithium cobalt oxide, and their preparation methods and applications, belonging to the field of battery materials technology. The chemical formula of the sheet-like porous cobalt chloride is M. x Co 1‑x Cl2, 0≤x≤0.5, M is a metallic element other than cobalt; the tap density of this sheet-like porous cobalt chloride is not less than 1 g / cm³. 3 Specific surface area not less than 1.8m² 2 / g、D v10 Not less than 4.5μm, D v50 Not less than 8.5μm, D v90 The diameter is not less than 20 μm. This sheet-like porous cobalt chloride has a high tap density, a large specific surface area and pore volume, and a relatively uniform pore size, which is beneficial to increasing sintering activity. Moreover, when it is mixed with lithium source for calcination, its sheet-like porous structure is also conducive to the uniform diffusion of lithium ions into the bulk phase of the material, making the lithium ion distribution more uniform, which in turn helps to improve the electrochemical performance of the cathode material and the battery.