880 results about "Nitrogen doping" patented technology

The invention provides a preparation method of a porous carbon-silicon composite negative electrode material of a lithium battery. The preparation method comprises the following steps: constructing a multi-stage template system; carrying out carbon precursor impregnation and gradient temperature carbonization on the multistage template system; removing the template to form a gradient porous carbon carrier; carrying out gradient temperature zone silane deposition; and plasma-assisted carbon coating and nitrogen doping are carried out. According to the method, a silicon dioxide sphere hard template is combined with cetyltrimethylammonium bromide and a block copolymer soft template to form a porous carbon carrier with a micropore-mesopore-macropore three-stage structure, and gradient distribution of silicon in porous carbon is realized by utilizing a three-temperature-zone fluidized bed reactor and a pulse type deposition technology, so that the silicon-based porous carbon composite material is obtained. The problem of volume expansion of the silicon material is effectively relieved and the material cycling stability is improved. The porous carbon-silicon composite negative electrode material prepared by the invention has high specific surface area, excellent ion transmission channel and good structural stability, and can be applied to a high-energy-density lithium ion battery.

The invention discloses a preparation process of a modified porous carbon material catalyst. The preparation process comprises the following steps: (1) mixing and calcining a biomass precursor and a template agent to prepare graded porous carbon; (2) low-frequency plasma pretreatment and high-frequency plasma fluorination modification are adopted; (3) introducing the pulse plasma into a nitrogen doping site; (4) spraying ionic liquid and activating H2 plasma to form a B / F co-doped layer; and (5) loading alloy nanoparticles such as PtRu through pulse electrodeposition. According to the obtained catalyst, biomass derived porous carbon serves as a carrier, a fluorine / nitrogen co-doped active layer is constructed on the surface of the carrier through multi-frequency plasma synergistic modification and ionic liquid auxiliary modification, superfine precious metal nanoparticles are loaded, the hydrogen evolution overpotential of the catalyst is smaller than or equal to 28 mV under the current density of 10 mA / cm < 2 >, the activity attenuation is smaller than 5% after 1000 times of circulation, and the catalyst has a good catalytic activity. The water electrolysis hydrogen production device is suitable for a large-scale water electrolysis hydrogen production device.

The invention discloses a silicon-carbon negative electrode material, a preparation method thereof and a lithium ion battery, and relates to the technical field of lithium ion battery negative electrode materials. The material sequentially comprises a porous silicon core, a transition layer and a shell from inside to outside, the transition layer is a nitrogen-doped SiC / C composite layer, the shell comprises a graphene / carbon nanotube skeleton and MXene quantum dots, the MXene quantum dots are embedded in the graphene / carbon nanotube skeleton, boric acid ester bonds exist between carbon nanotubes and graphene, and the MXene quantum dots are embedded in the graphene / carbon nanotube skeleton. The silicon-carbon negative electrode material is based on dual-network dynamic bonding and stress gradient regulation and control, the cycle performance of the material can be remarkably improved, and the service life of the material can be remarkably prolonged.

The invention belongs to the technical field of negative-electrode-free sodium metal batteries, and particularly discloses a negative-electrode-free sodium battery modified current collector and a preparation method and application thereof.The preparation method includes the steps that on the basis of polypyrrole preparation, transition metal salt is added, and the nitrogen doping type in polypyrrole-derived nitrogen-doped nano carbon particles is regulated and controlled. The negative-electrode-free sodium battery modified current collector prepared by the preparation method disclosed by the invention is high in relative content of N-6 and N-5 type doped nitrogen, so that the sodium affinity of a nitrogen-doped coating is improved, the nucleation over-point location of sodium metal is reduced, the reversibility of a sodium deposition / stripping reaction is improved, and the electrochemical performance of a negative-electrode-free sodium battery is further improved.

The invention discloses a silicon-carbon material as well as a preparation method and application thereof. The silicon-carbon material comprises nitrogen-doped porous carbon and an amorphous carbon layer coating the nitrogen-doped porous carbon, and pores of the nitrogen-doped porous carbon are filled with boron-doped nano silicon. The nitrogen-doped porous carbon improves the affinity of silane gas while improving the electron conductivity, a high-conductivity and high-density silicon-carbon composite structure is realized, the boron-doped nano silicon and the nitrogen-doped porous carbon form a nano heterojunction site, and the migration rate of lithium ions is improved, so that electrochemical reaction kinetics is improved, and the electrochemical performance of the lithium ion battery is improved. The material has the advantages of high rate and long cycle performance.

The invention discloses a composite coated silicon-carbon negative electrode material as well as a preparation method and application thereof, and relates to the technical field of lithium ion batteries. The method comprises the following steps of: oxidizing and etching graphite in mixed gas of air and nitrogen at the temperature of between 400 and 500 DEG C to form graphite oxide; the preparation method comprises the following steps: dispersing water-soluble asphalt, graphene, nano silicon, melamine and monoammonium phosphate in water to form a composite liquid; and then mixing the composite liquid with graphite oxide, and then carrying out carbonization treatment. The high-performance silicon-carbon composite negative electrode material is prepared through graphite oxidation etching and a composite coating process, nano silicon is uniformly dispersed in carbon pores which are stably combined on the surface of graphite and have rich mesoporous structures, graphene and a nitrogen-doped carbon layer form a three-dimensional conductive network, and the composite negative electrode material is applied to lithium ion batteries and can be applied to lithium ion batteries. And the lithium ion battery has good low-temperature charging proportion, first efficiency and cycle performance.

The invention discloses a silk protein-MXene composite film and a preparation method thereof. The silk protein-MXene composite film sequentially comprises a conductive surface layer, a porous response layer and a supporting bottom layer from top to bottom, the invention relates to the technical field of composite films. According to the fibroin-MXene composite film and the preparation method thereof, a three-layer gradient structure is formed by the conductive surface layer, the porous response layer and the supporting bottom layer, good conductivity and electromagnetic shielding effectiveness are ensured by utilizing oriented arrangement of MXene of the conductive surface layer, gallic acid and MXene form a hydrogen bond network, and nitrogen-doped carbon quantum dots coat the surface of MXene to form a physical barrier, so that the electromagnetic shielding effect is improved, and the electromagnetic shielding effect is improved. Through double oxidation resistance of gallic acid and nitrogen-doped carbon quantum dots, a sponge body structure formed by the porous response layer is matched to endow the composite film with high-sensitivity response to external stimulation, the supporting bottom layer is crosslinked by hexamethylene diisocyanate and enhanced by nanocellulose, the tensile strength is improved, and the tensile strength of the composite film is improved. And the contradiction between the mechanical property and the conductivity of the traditional composite film is effectively solved.

The invention discloses a fluorine-nitrogen-doped carbon-based oxygen reduction electrocatalyst for a zinc-air battery and a preparation method of the fluorine-nitrogen-doped carbon-based oxygen reduction electrocatalyst, and belongs to the technical field of catalysts. According to the method, a fluorocarbon mixture is rapidly treated through Joule heat to achieve efficient fluorine doping, then nitrogen doping is conducted through an ammonia gas plasma technology, and therefore an original carbon precursor is converted into fluorine-nitrogen-doped carbon. The catalyst material is short in preparation time and high in production efficiency, the content configuration of fluorine and nitrogen doped in fluorine-nitrogen-doped carbon finally formed by accurately controlling the temperature and time of Joule heat treatment and the power and time of plasma treatment is controllable, the morphology and the pore structure are controllable, high electro-catalytic performance is guaranteed, and the catalyst material is suitable for industrial production. The preparation method is high in production efficiency and low in cost, and has large-scale amplification potential.

The invention provides a super-hydrophobic passion fruit peel carbon aerogel VOCs adsorbent based on low-temperature plasma synergistic nitrogen doping modification and a preparation method thereof, and relates to the technical field of VOCs adsorbents. The super-hydrophobic passion fruit peel carbon aerogel VOCs adsorbent based on low-temperature plasma synergistic nitrogen doping modification is prepared by crushing passion fruit peel, mixing the crushed passion fruit peel with a nitrogen-containing compound to form gel, performing low-temperature plasma modification, performing freeze drying, performing high-temperature carbonization, and performing water washing and drying. The adsorbent is spherical, and the water contact angle is 115.8 degrees to 152.4 degrees. The adsorbent disclosed by the invention has the advantages of super hydrophobicity, high specific surface area, developed microporous structure, excellent VOCs adsorption performance, broad-spectrum adsorption capacity, good reusability and mechanical strength, the preparation method is simple in process, green and environment-friendly, low in cost and good in universality, a new technical scheme is provided for VOCs treatment in a high-humidity environment, and the adsorbent has a good application prospect.

An electrode structure for a solid-state or semi-solid-state battery is provided in which NCM electrode particles coated with an interphase layer and a nitrogen-containing carbon layer are disposed. [Solution] The NCM electrode particles comprise NCM (nickel-cobalt-manganese oxide) particles (15), primary particles (30) that coat the outer surfaces of the NCM particles, an interphase layer (16) that includes a glass phase layer (241) and a plurality of ceramic particles (242), and a nitrogen-containing carbon layer (35) that coats the exterior of the primary particles. Nitrogen-doped carbon molecules in the nitrogen-containing carbon layer aid in the conduction of electrons and lithium ions, modifying the electrical potential of the NCM particles. The nitrogen-containing carbon layer is formed by coating the surfaces of the primary particles with a nitrogen-containing polymer material and calcining the material in an inert atmosphere. Conjugated bonds are formed between the carbon and nitrogen, modifying the energy band structure, reducing the energy required for electrons to transition to the conduction band, and improving overall electronic conductivity.

The invention discloses a silicon / graphite / carbon-aluminum oxide composite negative electrode material and a green preparation method thereof, and belongs to the technical field of lithium ion batteries. Aiming at the problems of high volume expansion rate and poor cycling stability of a silicon-based negative electrode and high cost of a traditional process, the invention innovatively provides the following scheme: 1) waste photovoltaic silicon wafer ball-milling liquid and waste graphite are taken as core raw materials, and resource recycling is realized; (2) phenolic resin and chitosan are adopted as double carbon sources, a nitrogen-doped carbon layer (the nitrogen content is 3-5 wt.%) is formed through pH-induced self-assembly, and the conductivity and the Li < + > diffusion rate are synchronously improved; and 3) aluminum nitrate is introduced for pyrolysis to generate 2-5nm aluminum oxide for doping, so that the side reaction of the electrolyte is inhibited, and the volume expansion of silicon is relieved (the expansion rate is less than or equal to 120%). The preparation process comprises the steps of silicon / graphite dispersion, double-carbon-source compounding, ammonia water regulation and control precipitation and gradient calcination. Experiments show that the specific capacity of the optimized material under the current of 0.5 A / g reaches more than 800mAh / g, the 100-time cycle capacity retention ratio is more than 98%, the 1000-time cycle capacity retention ratio is more than 80%, the reversible specific capacity under the multiplying power of 3A / g is more than 550mAh / g, and the raw material cost is reduced by 40%. The invention has the advantages of high capacity, long service life, environmental protection and economy, and provides an innovative solution for the fields of power batteries and energy storage.

The invention discloses a preparation method and application of an antioxidant MXene-based flowing electrode material capable of realizing efficient capacitance defluorination, and belongs to the technical field of water treatment. The preparation method comprises the following steps: sequentially carrying out nitrogen doping and cysteine modification on MXene to obtain the antioxidant MXene-based flowing electrode material capable of realizing efficient capacitance defluorination. The MXene is prepared by a Lewis acid fused salt etching method. According to the method disclosed by the invention, the electrochemical performance of the MXene electrode is effectively improved, the conductivity of the MXene electrode is enhanced, the protection of terminal groups is realized through cysteine modification, and the oxidation resistance of the MXene electrode is improved. The anti-oxidation MXene-based flowing electrode material prepared by the invention has high specific surface area, large pore volume and multiple adsorption sites, and can realize specific efficient adsorption of fluorine ions through ion intercalation and special functional groups at end positions.

The present invention belongs to the technical field of battery materials, and particularly relates to a composite phosphate-based positive electrode material, and a preparation method therefor and the use thereof. The composite phosphate-based positive electrode material comprises a phosphate-based active core, wherein the outer surface of the phosphate-based active core is sequentially coated with a carbon coating layer, a nitrogen-doped carbon coating layer and a nitrogen-phosphorus co-doped carbon coating layer from inside to outside, wherein the carbon coating layer can improve the electronic and ionic conductivity of the composite positive electrode material, and optimize the particle size and morphology of the composite positive electrode material. The nitrogen-doped carbon coating layer improves the consistency and integrity of coating; and nitrogen-atom-doped carbon further enhances the electronic conductivity and lithium-ion diffusion of the carbon coating layer. Electron-rich clouds of P and N atoms in the nitrogen-phosphorus co-doped carbon coating layer can provide a rich conductive network, mutual contact is formed among different particles to form a series network, thus promoting the interfacial electron transport of the composite material during a charging and discharging process, and improving the cycling and rate performance of the composite phosphate-based positive electrode material during the charging and discharging process.

To provide a method for growing a silicon crystal without substantially including defects.SOLUTION: A method for growing a single crystal silicon ingot by the continuous Czochralski method is disclosed. A melt depth and heat conditions are fixed during growth since a silicon melt is continuously replenished as the silicon melt is consumed; a crucible position is fixed; a critical v / G is determined by a hot zone structure; the continuous replenishment of silicon to the melt during the growth can grow an ingot at a fixed pulling speed coincident with the critical v / G while growing the substantial part of an ingot main body; and the continuous replenishment of silicon is achieved by periodical or continuous nitrogen addition generating a nitrogen doped ingot.SELECTED DRAWING: Figure 5

The invention discloses a nitrogen-doped artificial graphite negative electrode material as well as a preparation method and application thereof. The preparation method comprises the following steps: pretreating and graphitizing raw material coke to obtain artificial graphite; and compounding the artificial graphite and a nitrogen source under an alkaline condition, and calcining to obtain the negative electrode material. According to the unique preparation method, the nitrogen element can be introduced into the artificial graphite, and the molecular structure of the ink sheet is changed due to the introduction, so that the connection between layers is enhanced. Compared with the conventional lithium ion battery, the lithium ion battery containing the nitrogen-doped artificial graphite negative electrode material has the advantages that the specific discharge capacity is improved, and the cycle life is remarkably prolonged.

The invention provides a negative electrode active material and a preparation method thereof, a negative electrode for a sodium ion battery, the sodium ion battery and an electric device. The negative electrode active material comprises a nitrogen-doped carbon sphere matrix and manganese monoxide embedded into the nitrogen-doped carbon sphere matrix, the average particle size of the manganese monoxide is 1.5 nm to 2.5 nm. In the negative electrode active material, the quantum-dot-level MnO is embedded into the nitrogen-doped carbon sphere matrix, so that a tight embedded structure (non-surface loading) of the quantum-dot-level MnO and the nitrogen-doped carbon spheres can be realized, volume expansion when sodium ions are embedded and removed is effectively relieved, and an efficient electron / ion transmission channel is provided. Meanwhile, the quantum dot-level MnO has a larger specific surface area, and provides more adsorption sites with the nitrogen-doped carbon, so that the composite material shows a pseudocapacitance-dominated sodium storage behavior, and is endowed with ultrahigh rate capability and ultra-long cycle life.

The invention discloses a composite positive electrode material which comprises a layered oxide and a coating layer, the general formula of the layered oxide is NaMe < 1-x > Al < x > O < 2 >, Me is one or more of nickel, iron, manganese and cobalt, and x is greater than 0; the coating layer is coated outside the layered oxide, the coating layer sequentially comprises a first coating layer, a second coating layer and a third coating layer from inside to outside, the first coating layer is titanium aluminum carbide, the second coating layer is titanium nitride, the third coating layer is nitrogen-doped polymeric porous carbon, and the composite positive electrode material forms an Al-N bond. The invention also discloses a positive plate with the composite positive electrode material and a sodium ion battery. The cyclic expansion rate can be effectively controlled while the cyclic electrical performance is guaranteed.

The invention relates to a modified graphite felt, a preparation method thereof and application of the modified graphite felt in a vanadium redox flow battery, and belongs to the technical field of redox flow battery electrodes. The method comprises the following steps: mixing a graphite felt with a mixed solution, and carrying out thermal reaction to obtain a metal organic framework two-dimensional nanosheet loaded graphite felt; sintering the graphite felt loaded by the metal organic framework two-dimensional nanosheet to obtain a modified graphite felt; wherein the mixed solution comprises a nitrogen-containing organic ligand and a metal salt. According to the modified graphite felt, the surface of the modified graphite felt is coated with a layer of metal nitrogen-carbon two-dimensional nanosheets, the metal organic framework two-dimensional nanosheets are formed by the coordination reaction of the nitrogen-containing organic ligands and the metal salts, metal is uniformly dispersed in the organic framework two-dimensional nanosheets, and then the metal is uniformly dispersed in the metal nitrogen-carbon two-dimensional nanosheets; therefore, numerous metal active sites are uniformly distributed on the surface of the obtained modified graphite felt, nitrogen element doping is formed at the same time, and the electrochemical performance of the modified graphite felt electrode is improved.

The invention discloses a microwave absorbing material of nitrogen-doped vanadium oxide and a preparation method thereof, the nitrogen-doped vanadium oxide is synthesized by combining a hydrothermal morphology control process with an annealing process for the first time, and the microwave absorbing performance of the nitrogen-doped vanadium oxide is systematically studied. The complex dielectric constant of the sample can be adjusted by adjusting the hydrothermal reduction pH value. When the pH value is 7, selective absorption of electromagnetic waves can be realized by adjusting the thickness of a sample, and the lowest reflection loss can reach 31.57 dB at 4.37 GHz. The reflection loss of the sample with the corresponding thickness in different frequency bands can be lower than 10dB, and the whole frequency range is almost covered. The excellent microwave absorption performance of the microwave absorption material of the nitrogen-doped vanadium oxide is attributed to the improvement of the conductivity in the nitrogen-doped double-phase vanadium oxide, good impedance matching and multiple reflection caused by a unique microstructure of the nitrogen-doped double-phase vanadium oxide. The microwave absorbing material of the nitrogen-doped vanadium oxide can be used as the absorbing requirements of different application scenes, and the corresponding thickness meets the absorbing requirements.

The invention relates to the technical field of agricultural application of nano materials, and discloses a preparation method and application of a photosynthetic accelerant containing carbon quantum dots. Urea and citric acid are adopted as raw materials, and the nitrogen-carbon molar ratio and hydrothermal reaction parameters are optimized, so that efficient doping of nitrogen and accurate regulation and control of the particle size are achieved, and the photosynthetic accelerant containing the carbon quantum dots is obtained. The nitrogen-doped carbon quantum dot photosynthetic promoter with excellent upconversion performance is successfully synthesized, the promoter has good water solubility and biocompatibility, the photosynthetic efficiency of plants can be greatly improved within the concentration range of 0-100 mg / L, a safe application window is defined, and by establishing foliage spraying and water planting dual-mode application specifications, the application range of the nitrogen-doped carbon quantum dot photosynthetic promoter is widened, and the application range of the nitrogen-doped carbon quantum dot photosynthetic promoter is widened. The problems that current crops are insufficient in solar spectrum utilization and low in light energy conversion efficiency are solved in a targeted manner by utilizing an ultraviolet light-photosynthetically active radiation conversion function mediated by the carbon quantum dots and combining the targeted enrichment permeation characteristic of the carbon quantum dots in chloroplast.

The invention provides a nitrogen-doped carbon material and a preparation method and application thereof, and belongs to the technical field of supercapacitor materials. A hydrothermal method and an activating agent activation method are adopted, nitrogen atom doping modification is performed on the carbon material, the specific surface area of activated carbon is increased, the pore diameter structure of the activated carbon is improved, the three-dimensional graded porous nitrogen-doped carbon material is obtained, the nitrogen-doped carbon material is used in a supercapacitor, and under the condition of the same size, the specific surface area of the carbon material is increased. The capacity and the energy density of the super capacitor are both improved by at least 40%, the size of the super capacitor required by the high-power-consumption field can be effectively reduced, and the application scene of the super capacitor is greatly expanded.

The invention relates to a composite solid-state electrolyte membrane and a preparation method thereof, a lithium ion battery and an electric device, the composite solid-state electrolyte membrane comprises a lithium phosphorus oxygen nitrogen solid-state electrolyte, the general formula of the lithium phosphorus oxygen nitrogen solid-state electrolyte is LixPOyNz, x is greater than 2.7 and less than or equal to 3, zlt; 0.45, 3 < (y + z) < 4; along the thickness direction of the solid electrolyte membrane, the nitrogen doping ratio of the lithium-phosphorus-oxygen-nitrogen solid electrolyte in the composite solid electrolyte membrane is gradually increased, and the corresponding oxidation stoichiometric number is gradually reduced. According to the composite solid electrolyte membrane, the capacity retention ratio, the cycling stability and the safety of the lithium ion battery are improved.

The invention provides a preparation method of a gate oxide layer and a gate, and the method comprises the steps: carrying out the rapid thermal annealing treatment of a silicon-based substrate in a nitrogen-containing gas atmosphere, which belongs to a non-destructive nitrogen doping mode, and carrying out the nitrogen pre-doping on the surface of the silicon-based substrate, so as to reduce the doping amount needed by the subsequent plasma nitrogen doping; therefore, the damage of the plasma nitrogen doping process to the SiON gate oxide layer is reduced, and the interface defect between the SiON gate oxide layer and the silicon-based substrate interface is reduced. Besides, after the nitrogen pre-doped layer is formed, the thermal oxidation process is carried out on the silicon-based substrate to form the silicon dioxide gate oxide layer, so that the damage to the SiON gate oxide layer film is reduced, and the interface defect between the SiON gate oxide layer and the silicon-based substrate interface is further reduced; moreover, the laser rapid annealing treatment can remove the intrinsic oxide layer on the surface of the SiON gate oxide layer, repair the damage to the crystal lattice of the SiON gate oxide layer caused by the plasma nitrogen doping treatment process, improve the film quality and repair the interface.

The invention discloses a p-type gallium oxide material and a preparation method and application thereof, and relates to the technical field of semiconductor materials. The method for preparing the p-type gallium oxide material comprises the following steps: placing a beta-Ga2O3 single crystal substrate in a cavity of a deposition system, introducing an organic gallium source and N2O, and carrying out homoepitaxial growth on the beta-Ga2O3 single crystal substrate through an organic metal chemical vapor deposition method to obtain the p-type nitrogen-doped beta-Ga2O3 material. In the process of homoepitaxial growth on a beta-Ga2O3 single crystal substrate, N atoms in N2O are doped into beta-Ga2O3 in a displacement doping form, so that the p-type nitrogen-doped beta-Ga2O3 material is formed. The preparation of the p-type beta-Ga2O3 material is realized in a homoepitaxy mode, and the p-type beta-Ga2O3 material can be used for preparing a transverse device and a longitudinal device, so that popularization and application of gallium oxide devices are facilitated.

The invention relates to a flow battery carbon-based electrode and a preparation method and application thereof, and the preparation method comprises the following steps: respectively dissolving cobalt salt and alkali in a polar organic solvent, and uniformly mixing to form a precursor solution; placing a carbon-based material in the precursor solution, and carrying out a hydrothermal reaction to obtain a carbon-based electrode precursor; and performing high-temperature carbonization on the carbon-based electrode precursor in an inert atmosphere, cooling to room temperature after the reaction is completed, and then cleaning and removing impurities from a product to obtain the carbon-based electrode, the polar organic solvent is at least one of formamide, acetonitrile and N, N-dimethylformamide; after cobalt cyanide is deposited on the surface of the carbon-based material, surface etching and nitrogen doping are carried out on the carbon-based material under the high-temperature condition, surface modification of the carbon-based material is achieved, the contact area of the surface of the carbon-based electrode and electrolyte is increased, and the electrochemical performance of the carbon-based electrode is improved.

The invention discloses a high-performance self-powered NO2 sensor based on a nitrogen-doped MOF-derived In2O3 core-shell fiber structure sensitive material and a preparation method of the high-performance self-powered NO2 sensor, and belongs to the technical field of semiconductor metal oxide gas sensors. The flexible NO2 sensor is composed of a friction nanometer generator and a flexible NO2 sensor based on a nitrogen-doped MOF-derived In2O3 core-shell fiber structure. The nitrogen-doped MOF-derived In2O3 core-shell fiber structure sensitive material prepared by the invention has layered pores of a core-shell structure and effective doping of nitrogen, so that reconstruction of a surface electronic state is facilitated, the gas-sensitive characteristic of a sensor to NO2 is effectively improved, and the material has good selectivity and relatively low detection lower limit. According to the self-powered NO2 sensor, the sensor and the friction nanometer generator are integrated, preparation of the self-powered NO2 sensor is achieved, resistance signals are converted into voltage signals, the sensitivity of the sensor is effectively improved, the response time is shortened, and an effective strategy is provided for high-performance and self-powered NO2 detection at the room temperature.

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 invention relates to the technical field of power cables, in particular to a cross-linked polyethylene insulated power cable wrapped by a high-water-resistance buffer layer and a preparation method of the cross-linked polyethylene insulated power cable wrapped by the high-water-resistance buffer layer, and the cross-linked polyethylene insulated power cable is prepared from the following raw materials in parts by weight: 100 parts of ethylene-vinyl acetate copolymer; 15 to 25 parts of conductive carbon black; 20 to 30 parts of sodium polyacrylate; and 10 to 15 parts of nano montmorillonite. Through the high-water-resistance buffer layer and innovative process design, the problems existing in a traditional cable are solved, and the water-resistance layer effectively blocks a water permeation path through composite water absorption and a nano barrier; nitrogen doping and dispersion optimization of conductive carbon black ensure the stability of resistivity; a plasma interface activation and microcapsule cross-linking technology improves interlayer bonding force and cross-linking uniformity, gradient degassing and low-temperature cross-linking are adopted in the preparation process, the production cycle is shortened, energy consumption is reduced, meanwhile, material degradation is avoided, the cable has high water resistance and long service life, and reliability and safety of power grid operation are remarkably improved.

The invention relates to the technical field of lithium ion batteries, in particular to a chromium-molybdenum double-doped lithium iron phosphate material as well as a preparation method and application thereof. The preparation method is used for solving the problems of low capacity, low electronic conductivity and poor cycling stability of the existing lithium iron phosphate material. According to the preparation method, chromium-molybdenum is doped into lithium iron phosphate, and the bond energy of a Cr-O bond and a Mo-O bond is stronger than that of a Fe-O bond, so that the dissolution loss of Fe < 2 + > in long-term circulation is reduced, and the battery capacity and the intrinsic electron conductivity of the material are improved; lithium iron phosphate is coated with nitrogen-doped carbon nanotubes, and nitrogen is doped in graphite crystal lattices of the carbon nanotubes, so that additional free electrons are provided, the intrinsic conductivity is improved, the resistance is reduced, the rate capability is improved, and the cycle life is prolonged; the polyaniline coating layer forms a barrier layer on the surface of the lithium iron phosphate particles, so that the cycle performance and the battery capacity are improved; the three components cooperate to improve the capacity, conductivity, rate capability and cycling stability of the material.

The invention relates to the technical field of lithium ion battery negative electrode material optimization, and discloses a porous carbon coated modified negative electrode material preparation method, which comprises: S1, low temperature pre-carbonization: forming an organic frame structure under the action of a carbon source, a nitrogen doping agent, a structure regulating agent and a sacrificial template; s2, etching to form a graded pore structure, and removing the sacrificial template by adopting a chemical etching method to form a carbon material framework with specific pore distribution; s3, high-temperature carbonization and structure reconstruction: performing high-temperature carbonization in an inert atmosphere to crystallize the carbon material, and optimizing pore distribution through atmosphere regulation and control; and S4, a porosity control method of the negative electrode material, wherein the pore distribution is regulated and optimized through the etching time and atmosphere. The conductivity, the structural stability and the compatibility with electrolyte of the negative electrode material are remarkably improved through cold plasma treatment and a low-temperature sintering technology, and the high-rate discharge capacity and the long-period stability of the battery are enhanced.