76results about How to "Shorten the diffusion distance" patented technology

The invention relates to a low-temperature graphite negative electrode material and a preparation method thereof, and belongs to the technical field of high polymer materials. According to the prepared low-temperature graphite negative electrode material, firstly, the surface of graphite is pre-oxidized through potassium persulfate, phosphorus pentoxide and concentrated sulfuric acid, and then under the action of sodium nitrate, potassium permanganate and hydrogen peroxide, graphite oxide is prepared; then, ammonium molybdate hydrate and thioacetamide are used as a molybdenum source and a sulfur source, graphite oxide is used as a supporting material, a molybdenum disulfide-graphite compound is synthesized, and the conductivity and the cycling stability are improved; secondly, the surface of the negative electrode is coated with amorphous resin carbon / nickel oxide, so that the ion diffusion efficiency of the low-temperature graphite negative electrode material is enhanced, and the electrochemical lithium storage performance is improved in a low-temperature environment; and finally, the surface of the amorphous resin carbon / nickel oxide is coated with a layer of polythiophene film, so that the rate capability of the negative electrode material is improved due to large surface area and high pores.

The invention discloses a porous silicon-carbon negative electrode material of a lithium ion battery as well as a preparation method and application of the porous silicon-carbon negative electrode material. The preparation method comprises the following steps: firstly, activating silicon nanoparticles by using a surfactant, so that the silicon nanoparticles are positively charged, and agglomeration of the silicon nanoparticles is avoided; secondly, nano active silicon and graphite are uniformly mixed and ball-milled, so that the active silicon is anchored in a graphite layer, and the conductivity of the whole material is improved; and uniformly mixing and ball-milling the silicon / graphite composite material, asphalt and potassium chloride, and then annealing and washing to obtain the porous silicon-carbon composite material. The activated nano silicon can effectively prevent agglomeration of nano silicon particles, the porous carbon prepared by taking potassium chloride as a template agent has the characteristics of environmental protection and no pollution, the potassium chloride can be recycled, and the prepared porous silicon carbon negative electrode material can enable a lithium ion battery to have relatively high initial coulombic efficiency and excellent cycling stability.

The invention belongs to the technical field of optical communication, and relates to a flexible silicon-based photoelectric device, a receiving end and a visible light communication system. The flexible silicon-based photoelectric device comprises a back electrode layer, a hole transport layer, a P-type silicon light absorption layer, an electron transport layer and a front electrode layer. The valence band side energy difference between the electron transport layer and the P-type silicon light absorption layer is greater than the conduction band side energy difference; the conduction band side energy difference between the P-type silicon light absorption layer and the hole transport layer is greater than the valence band side energy difference; the forbidden bandwidth of the electron transport layer is greater than 3.0 eV. The front electrode layer comprises a plurality of grid electrodes which are separately arranged on the surface of the electron transport layer. According to the scheme provided by the invention, the heterojunction is formed on the surfaces of the two sides of the P-type silicon light absorption layer, so that the intensity of a built-in electric field is effectively enhanced, and the flowing speed of photo-generated electrons and photo-generated holes in the device is accelerated, thereby improving the response speed of the device; and meanwhile, the collection efficiency of electrons and holes is improved, so that the photoelectric conversion efficiency of a photoelectric device is improved.

The invention provides a multiphase reinforced high-toughness and high-conductivity TiB2-based composite material and an in-situ preparation method thereof, and belongs to the field of TiB2 composite materials. The preparation method comprises the following steps: selecting a Ti source, B4C powder and TiB2 powder with different particle sizes as raw materials, firstly mixing a sintering aid, then adding the aid into a TiB2 matrix, carrying out ball-milling mixing and screening granulation, and carrying out oscillation hot pressing or spark plasma sintering under a vacuum condition to obtain the multiphase reinforced TiB2-based composite material. According to the preparation method, an in-situ reaction sintering process is adopted, and a competitive reaction in a system is regulated and controlled, so that the metallurgical-grade combined high-toughness and high-conductivity TiB2-based composite material which takes a TiB2 matrix as a framework and multiple reinforced phases (TiCx, TiB, C and the like) as fillers is constructed. Meanwhile, the cost of the raw materials is low, the preparation process is simple, and the optimization of the components, the structure and the performance of the TiB2-based composite material can be realized only by regulating and controlling the component proportion of the raw materials, so that the application requirements in the extreme environment fields such as aluminum electrolysis cathode materials, high-temperature engine materials and aerospace materials can be better met.

The invention relates to the technical field of batteries, in particular to a positive electrode material and a preparation method thereof, a positive plate and a sodium ion battery. The positive electrode material comprises: a) a base material having a chemical formula of Na < 3 + x + y > V < 2-x-y > CoxCuy (PO4) 3, 0.01 < = x < = 0.12, 0.01 < = y < = 0.12, and 0.02 < = x + y < = 0.2; b) a metal oxide anchored to a portion of the surface of the matrix material; and c) a carbon coating layer arranged on at least part of the surface of the matrix material anchored with the metal oxide. After Co < 2 + > and Cu < 2 + > double-element doping, lattice distortion can be formed in the material, an ion transmission channel is widened, the diffusion resistance of Na < + > in the material is reduced, and diffusion kinetics is improved.

The invention provides a preparation method of a diaphragm-free all-solid-state battery, and belongs to the technical field of solid-state batteries, and the preparation method comprises the following steps: S1, coating the surface of a positive current collector with positive slurry to obtain a positive plate; s2, coating the surface of the positive plate with acting slurry to form an acting layer; the acting slurry comprises the following components in percentage by mass: 15-18% of lithium niobate, 5-6% of nano aluminum oxide, 3-5% of a binder and the balance of a solvent; s3, coating the surface of the acting layer with electrolyte slurry to form a semi-solid electrolyte; the electrolyte slurry comprises the following components in percentage by mass: 5-7% of porous carbon coated alumina particles, 7-9% of a binder and the balance of electrolyte; s4, the surface of the semi-solid electrolyte is coated with negative electrode slurry, then a negative current collector is added, the surface is pressurized by 450-650 N / m < 2 >, heating treatment is conducted for 12-15 h at the temperature of 80-100 DEG C in an inert environment, and a battery cell body is obtained; and S5, packaging, compacting and sealing the battery core body to obtain the diaphragm-free all-solid-state battery. According to the invention, the cycle life of the prepared diaphragm-free all-solid-state battery can be prolonged.

The invention belongs to the technical field of battery materials, and particularly relates to a carbon-coated iron-based composite phosphate positive electrode material as well as a preparation method and application thereof. The preparation method comprises the following steps: performing wet grinding on iron salt, M salt, a sodium source, a phosphorus source, a complexing agent and a solvent according to a stoichiometric ratio to obtain slurry A; carrying out spray drying on the slurry A to obtain solid powder B; pre-sintering the solid powder B in an inert atmosphere to obtain a precursor C, grinding the precursor C into powder, compacting the powder, sintering the powder at a high temperature in the inert atmosphere, and crushing the powder to obtain the carbon-coated iron-based composite phosphate positive electrode material. Wherein the chemical formula of the iron-based composite phosphate positive electrode material is Na4 [FexM1-x] 3 [PO4] 2P2O7, M is one or more of Ni, Co, Mn, Mg, Ti, Zn and Cu, and x is more than 0 and less than 1. The prepared positive electrode material is uniform in element distribution, excellent in cycling stability and high in specific capacity.

This invention relates to the field of hafnium carbide technology and discloses a thermal decomposition preparation process for hafnium carbide precursors. The process includes: dissolving hafnium tetrachloride in anhydrous ethanol, adding propylene oxide dropwise for neutralization and acid removal to obtain a neutral ethanol-hafnium precursor solution; adding ethyl acetoacetate methacrylate and heating for coordination to obtain a hafnium coordination monomer solution; adding acrylonitrile and an initiator and heating for polymerization; when the viscosity of the reaction solution increases, injecting a dimethyl sulfoxide hot solution of melamine as a locking liquid; precipitating, separating, and drying to obtain the hafnium carbide precursor; and after oxidative crosslinking treatment, calcining at high temperature under an inert atmosphere to undergo carbothermic reduction to obtain hafnium carbide powder. This invention achieves molecular-level dispersion of precursor components through liquid-phase coordination and in-situ network locking, effectively reducing the reaction temperature and inhibiting grain agglomeration, thus producing high-purity, ultrafine hafnium carbide powder.

The invention relates to a preparation method of a seaweed derived alloy carbon sodium ion battery negative electrode material, and belongs to the technical field of sodium ion batteries, and the specific scheme comprises the following steps: step 1, drying cleaned seaweed leaves; 2, chopping the dried seaweed leaves, and calcining and carbonizing the chopped seaweed leaves and an activating agent; 3, washing the carbonized material with deionized water until the carbonized material is neutral, and drying to obtain a seaweed precursor; and 4, uniformly grinding the seaweed precursor and two metal salts, and reacting under microwave radiation to obtain the seaweed-derived alloy carbon sodium ion battery negative electrode material. The seaweed-derived alloy carbon prepared by the method can generate more active sites to store sodium ions, and the diffusion rate of the sodium ions is improved, so that the electrochemical performance is improved. In addition, in the synthesis process, the speed is very high, no solvent exists, and the yield is high.

The invention discloses a porous Fe2O3-Mn2O3 core-shell cubic structure material for a lithium ion battery and a preparation method of the porous Fe2O3-Mn2O3 core-shell cubic structure material, and belongs to the technical field of lithium ion battery electrode materials. The preparation method comprises the following steps: adding (CH2OH) 2 into deionized water, uniformly stirring, adding Fe (NO3) 3.9 H2O, MnSO4.H2O and CH4N2O into an ethylene glycol aqueous solution, uniformly stirring, heating and stirring in a pressurized reaction kettle, carrying out a hydrothermal reaction, taking out, cooling to room temperature, centrifugally washing the obtained precipitate with absolute ethyl alcohol and deionized water for several times, and drying to obtain the Fe / MnSO4.H2O / CH4N2O composite material. And finally, sintering the precursor powder in an air atmosphere, thereby obtaining the composite material. When the prepared porous Fe2O3-coated Mn2O3 core-shell cubic structure material is used as a lithium ion battery negative electrode active material, the characteristics of high capacity, good rate capability and good cycling stability are shown.

The invention discloses a porous carbon fiber supported black phosphorus / nitrogen-doped carbon composite material as well as a preparation method and application thereof, and belongs to the field of new energy materials and devices. A nitrogen-doped carbon-coated porous carbon fiber conductive frame is prepared by using a metal-assisted chemical etching technology, then red phosphorus is converted into black phosphorus by adopting a solvothermal and confinement growth strategy, and the black phosphorus grows in a pore channel of the nitrogen-doped carbon-coated porous carbon fiber frame in an in-situ confinement manner, so that the high-performance self-supporting phosphorus / carbon heterostructure electrode material is constructed and obtained. The three-dimensional nitrogen-doped carbon-coated porous carbon fiber conductive framework realizes high-speed electron / ion transmission and limits the expansion of the electrode structure; abundant nitrogen doping defects are beneficial to abundant reaction active sites and enhancement of reaction kinetics; the in-situ formed phosphorus / carbon heterogeneous interface can promote electron transfer and ion diffusion, stabilize the electrode structure and realize stable, rapid and reversible sodium storage.

The invention provides a preparation method of a high-compaction high-capacity lithium iron phosphate material, which comprises the following steps: (1) mixing polyvinyl alcohol, iron phosphate, a lithium source, a carbon source and water to obtain slurry A; mixing iron phosphate, a lithium source, a carbon source and water to obtain slurry B; (2) performing spray drying on the slurry A, and performing low-temperature sintering to obtain a black material C; performing spray drying on the slurry B, and performing high-temperature sintering to obtain a black material D; and (3) mixing the black material C and the black material D, crushing, adding barium titanate, carrying out ball milling, and drying to obtain the lithium iron phosphate material. The polyvinyl alcohol is partially acetylated modified polyvinyl alcohol. The sintering temperature is reduced by adding the modified polyvinyl alcohol to prepare the compact lithium iron phosphate material with smaller particle size, and the lithium iron phosphate material and the lithium iron phosphate material obtained by high-temperature sintering form grading of large and small particles, so that the compaction density of the lithium iron phosphate is improved.

The present invention provides a process for reducing graphitization of carbon steel, comprising the following steps: heating the carbon steel to 1000°C for austenitization and heat preservation, and then performing a controlled rolling and controlled cooling process to reduce the degree of graphitization of the carbon steel. The present invention uses a controlled rolling and controlled cooling process to roll in the non-recrystallization zone of austenite of high carbon steel, increase the deformation band in the deformed austenite grain, form fine lamellar pearlite or annealed pearlite, reduce the diffusion distance of carbon and prevent carbon from agglomerating to form graphite. After graphitization of high carbon steel, gas expansion will occur, and the product is prone to cracks. At present, alloy elements such as chromium, titanium, and niobium are usually added to the steel to prevent graphitization, which is expensive. The process method provided by the present invention does not need to add the above alloy elements, and can eliminate the graphite that has been formed in medium and high carbon steels; the process method of the present invention is simple to operate, has a low processing temperature, and has a low application cost, and can process ordinary medium and high carbon steels with graphitization problems.

The electrochemical reaction device comprises a plurality of electrochemical reaction units which are sequentially connected in series; the electrochemical reaction unit comprises a vertical cylindrical first reaction part and a U-shaped cylindrical second reaction part; the upper end and the lower end of each electrochemical reaction unit are provided with connecting pieces connected with the screen plate, and the connecting pieces are used for fixing the outer electrode and the inner electrode and are hermetically connected with the first reaction part and the second reaction part; an automatic exhaust valve is arranged above the second reaction part connected in each electrochemical reaction unit; gas in the electrolysis system is discharged out of the reaction system; attachments on the surface of the electrode are easy to clean and convenient to disassemble; installation is simple and fast; catalytic layers for electro-catalytic reaction are prepared on the inner wall of the outer electrode and the outer wall of the inner electrode of each electrochemical reaction unit; and catalyst layer materials on the surfaces of the positive and negative electrodes can be timely repaired.

The application discloses a preparation method and equipment of a chlorin supermolecular assembly, and belongs to the technical field of functional nanomaterials. The Y+S composite microfluidic chip is designed, the nucleation and growth kinetics of Ce6 molecules are precisely controlled by using the Dean vortex flow induced by the S-shaped flow channel, directional preparation of the nanospherical Ce6 supermolecular assembly is realized, and meanwhile, the assembly has a narrow particle size distribution (PDI<0.1), and the problems of great morphology heterogeneity and poor controllability of the traditional method are completely solved, thereby providing technical support for the morphology standardized preparation of the Ce6-based nanodelivery system.

The invention discloses an ultrathin porous nickel hydroxide nanosheet supercapacitor electrode material and a preparation method and application thereof, and belongs to the technical field of capacitor electrode materials. According to the material, an amorphous alloy serves as a core layer to play a self-supporting role, nano-porous nickel layers on the two sides provide a nickel source for in-situ growth of nickel hydroxide, and mutually-crossed ultrathin porous nickel hydroxide on the outermost layer serves as an active substance and vertically grows on the surface of the nano-porous nickel in situ; the diameter of the ultrathin porous nickel hydroxide is 0.5-2 mu m, the thickness of the ultrathin porous nickel hydroxide is 2-10 nm, and the size of holes in the nanosheet is 5-8 nm. The preparation method of the material has the advantages that the operation is simple, the cost is low, high temperature and use of nickel salt are not needed, the repeatability is good, and Ni (OH) 2 grows on nano porous nickel in situ and is a self-current-collector electrode material.

The invention discloses a preparation method of a high-rate lithium iron manganese phosphate positive electrode material and a lithium battery, belonging to the technical field of lithium batteries. A double coating layer is formed on the surface of the lithium iron manganese phosphate material by combining the two methods of in-situ coating of lithium cobalt oxide nanoparticles and polyvinyl alcohol / chitosan gel coating. The main coating layer of lithium cobalt oxide can supplement lithium elements to increase the specific capacity, and based on its layered structure, it can inhibit the growth of particles while facilitating the diffusion of lithium ions. Polyvinyl alcohol and chitosan are cross-linked on the surface of the material to form a gel coating to prevent particle agglomeration. Due to the cross-linking to form a network structure, the carbon layer formed by carbonization is continuous and uniform. Based on the action of the double coating layer, the lithium iron manganese phosphate positive electrode material has high-rate performance, high specific capacity and good cycle performance.

The invention discloses a lithium manganese iron phosphate positive electrode material and a preparation method thereof, and belongs to the technical field of lithium batteries, the preparation method of the lithium manganese iron phosphate positive electrode material comprises the following steps: dissolving a soluble iron source, a soluble manganese source and a complexing agent in 100 mL of deionized water, adjusting the pH value of the mixed solution to 2-4, and heating and stirring for 2-6 h to obtain xerogel; calcining the dry gel, taking out, cooling and grinding to obtain powder A; calcining the powder A in a nitrogen atmosphere, and grinding to obtain powder B; uniformly mixing the powder B, a lithium source, a phosphorus source, a carbon source and 70mL of deionized water, sanding, and spray-drying slurry after sanding to obtain powder C; and calcining the powder C in a nitrogen atmosphere, crushing, and sieving to obtain the lithium iron manganese phosphate positive electrode material. The lithium manganese iron phosphate positive electrode material prepared by the method has excellent conductivity and cycle performance.

This invention discloses a method for preparing hierarchical porous indium oxide nanotubes for lithium-ion battery anodes, comprising the following steps: Step (1) Indium salt and terephthalic acid are placed in an organic solvent and stirred evenly under oil bath conditions to obtain a homogeneous dispersion; Step (2) The homogeneous dispersion is further heated and stirred continuously to carry out the reaction, and after the reaction is completed, it is naturally cooled to room temperature to obtain a mixed reaction system; Step (3) The mixed reaction system is filtered, and the solid product obtained by filtration is washed with anhydrous ethanol and dried to obtain the precursor MIL-68(In); Step (4) The precursor MIL-68(In) is placed in a tube furnace and pyrolyzed in an air atmosphere to obtain hierarchical porous indium oxide nanotubes. This invention can solve the problems of poor cycle performance and rate performance of existing In2O3-based anode materials.

The present invention relates to the technical field of sodium ion battery electrode materials, specifically a single-phase ternary iron-based sulfide selenide composite material and its preparation method and application, wherein the preparation method is to use sodium alginate with abundant reserves as a precursor; utilize the abundant carboxyl and hydroxyl groups in the structure to crosslink the chelation between iron ions in one step to form a gel of sodium alginate wrapped metal; after the gel is refrigerated, it is simultaneously sulfide-selenized with sulfur and selenium sources by vapor deposition in an inert atmosphere, and the corresponding single-phase ternary iron-based sulfide selenide composite material can be obtained after cooling to room temperature. The present invention has the characteristics of improving material structure and performance, improving the electrochemical properties of such negative electrode materials, including material conductivity, structural stability, specific capacity, cycle stability and rate performance of sodium ion batteries, and significantly improving the cycle performance and rate performance of sodium ion batteries.

The present invention relates to the field of sodium ion battery electrode materials, specifically a selenium-induced defect copper-based sulfur / selenide material and its preparation method and application, and a novel copper-based metal organic framework compound Cys-Cu precursor is preferentially prepared by a coprecipitation strategy; the precursor and a selenium source are then pyrolyzed and selenized under an inert atmosphere, and then naturally cooled to room temperature to obtain a product. The preparation method makes full use of the advantages of heteroatoms such as S / N in the ligand in the precursor, and a copper-based sulfur-selenide composite material with rich vacancies is obtained only by the preparation and selenization of the precursor, and the manufacturing process is simple and efficient, the cycle is short, and the stability is good. The composite material obtained by the method contains rich cation vacancies and a heterogeneous interface spontaneously constructed by copper-based sulfide and selenide, which can not only improve the material conductivity, promote effective electron / ion transport, but also create more sodium storage active sites, and further improve the material sodium storage capacity and structural stability.

The invention discloses a modified lithium iron manganese phosphate positive electrode material and a preparation method and application thereof, and belongs to the technical field of lithium ion battery positive electrodes. The preparation method comprises the following steps: mixing a phosphoric acid source, a manganese source, an iron source, a lithium source, a carbon source, a surfactant and a cosolvent, and carrying out ball milling and vacuum drying to obtain a lithium iron manganese phosphate precursor; and carrying out high-temperature sintering on the lithium manganese iron phosphate precursor to obtain the modified lithium manganese iron phosphate positive electrode material. And then taking an aluminum foil as a substrate, and coating the modified lithium iron manganese phosphate positive electrode material on the substrate to obtain the positive electrode of the lithium battery. The surface morphology of the lithium manganese iron phosphate can be improved by modifying the lithium manganese iron phosphate through the surfactant, so that the capacity of the battery prepared by taking the modified lithium manganese iron phosphate as the positive electrode material is improved, and the battery has relatively high cycling stability and rate capability.

This invention relates to a high-entropy polymetallic organic framework-assisted reinforced magnesium hydride solid-state hydrogen storage material, which is composed of magnesium hydride and a high-entropy polymetallic organic framework in a mass ratio of 30-90:10-70, and its chemical formula is MgH. 2 -(FeCoNiCrMn) 3 O 4 The high-entropy multimetal-organic framework is composed of five different metal cations coordinated in an equimolar ratio; the metal cations are selected from cobalt, nickel, iron, chromium, and manganese. The material of this invention exhibits a high-entropy effect and possesses excellent thermodynamic properties and hydrogen storage cycle performance.

The invention relates to a steam inlet type tray and cooking equipment, which can shorten the steam diffusion distance and ensure that the steam diffusion path of food cooking in each layer of tray is kept consistent so as to improve the cooking experience of a user. The steam admission type tray comprises a tray main body which is provided with a cooking area and an edge area which is located on the periphery of the cooking area and used for being in lap joint with an inner container; the steam inlet pipe is provided with a steam inlet used for being communicated with a steam generator located outside the inner container, a steam inlet channel extending from the steam inlet along a pipe body and a plurality of steam outlets distributed along the pipe body at intervals and communicated with the steam inlet channel. The fixing frame extends upwards from the edge area of the tray body, and the fixing frame is fixedly connected to the steam inlet pipe so that the steam inlet pipe can be partially supported on the cooking area of the tray body.

The invention discloses a spherical silicon-carbon composite material and a preparation method and application thereof, and the preparation method comprises the following steps: dissolving a binder in a first solvent, and carrying out first stirring treatment to obtain a first stirred material; adding graphite into the first stirred material, and carrying out second stirring treatment to obtain a second stirred material; adding a silicon source, a second solvent and a conductive agent into the second stirred material, and carrying out second stirring treatment to obtain a third stirred material; the third stirred material is subjected to spray drying treatment, the spherical silicon-carbon composite material is obtained, and the spherical silicon-carbon composite material comprises a spherical structure (a graphite layer) formed by stacking graphite flakes and silicon combined to the surface of the spherical structure. Certain gaps exist between the graphite layers of the spherical silicon-carbon composite material prepared by the method, a space is provided for volume expansion of silicon, the nanometer silicon is combined on the graphite layers, the diffusion distance of lithium ions is shortened, the combination of the nanometer silicon and the graphite layers is very tight, and the dynamic performance of a lithium ion battery is facilitated.

The invention relates to the technical field of lithium batteries, in particular to an LMFP composite positive electrode material and a preparation method thereof. According to the method, the LMFP composite positive electrode material is prepared from a composite carbon source, and the composite carbon source comprises cane sugar, polyvinyl alcohol and polystyrene microspheres. According to the method, the LMFP composite positive electrode material with proper carbon content, uniform particle size distribution, porosity and good electrochemical performance can be obtained; the method has the advantages of simple steps, mild conditions, low cost, no need of introducing chemical substances with strong toxicity, and good environmental protection characteristic; the LMFP composite positive electrode material has the advantages of high energy density, small electrochemical polarization, good rate capability and good cycle stability.

The present application relates to a molecular sieve composition, a preparation method thereof and application thereof. The molecular sieve composition of the present application comprises a mosaic molecular sieve of a TON structure molecular sieve and a 5A type molecular sieve. The molecular sieve composition of the present application has a dual function of adsorption and hydroisomerization.

The invention relates to the technical field of batteries, in particular to a composite positive electrode material and a preparation method and application thereof. The composite positive electrode material comprises a carbon nanotube and amorphous manganese-based oxide nanoparticles located on the surface of the carbon nanotube, the chemical general formula of the amorphous manganese-based oxide nanoparticles is (NiO) x (MnO) y, 0.25 < = x < = 0.75, 0.25 < = y < = 0.75, and x + y = 1. According to the composite positive electrode material disclosed by the invention, the amorphous manganese-based oxide is uniformly coated on the surface of the carbon nanotube, so that the composite positive electrode material has excellent cycle life and specific discharge capacity.

This invention relates to the field of batteries, and more particularly to a nitrogen-doped carbon / tungsten diselenide nanosphere composite material, its preparation method, and its applications. This invention achieves tight coupling between few-layer WSe2 nanosheets and a nitrogen-doped carbon framework through a process combining complexation-polymerization and subsequent selenization. The resulting material consists of nanosphere particles, providing more electrochemical active sites and shortening the zinc ion diffusion distance. By introducing a nitrogen-doped carbon framework, this invention effectively improves the overall conductivity of the composite material and suppresses the stacking and aggregation of WSe2 nanosheets during charge and discharge, thereby significantly improving rate performance and cycle stability.

A method for manufacturing a high-strength steel sheet having a tensile strength of more than 1100 MPa and a yield strength of more than 700 MPa, a uniform elongation UE of at least 8.0% and a total elongation of at least 10%, made of a steel containing in percent by weight: 0.1% ≤ C ≤ 0.25%, 4.5% ≤ Mn ≤ 10%, 1% ≤ Si ≤ 3%, 0.03% ≤ Al ≤ 2.5% , the remainder being Fe and impurities resulting from the smelting, the composition being such that CMnIndex = Cx(1 + Mn / 3.5) ≤ 0.6, the method comprising the steps of annealing a rolled sheet made of said steel by soaking it at an annealing temperature TA higher than the Ac1 transformation point of the steel but less than 1000°C, cooling the annealed sheet to a quenching temperature QT between 190°C and 80°C at a cooling speed sufficient to obtain a structure just after cooling containing martensite and retained austenite, maintaining the steel sheet at an overaging temperature PT between 350°C and 500°C for an overaging time Pt of more than 5 s cooling the sheet down to the ambient temperature. Sheet obtained.