1083 results about "Polysulfide" patented technology

The invention provides lithium sulfide as well as a preparation method and application thereof. The preparation method of the lithium sulfide comprises the following steps: providing a mixed solution containing a lithium-containing compound and liquid sulfur which are uniformly mixed, and enabling the mixed solution to be in contact with a reducing gas so as to carry out a lithium sulfide synthesis reaction, after the synthesis reaction of the lithium sulfide is finished, at least removing part of sulfur in the obtained reaction mixture to obtain a crude finished product; and calcining the crude finished product to convert lithium polysulfide in the crude finished product into lithium sulfide to obtain a lithium sulfide product. According to the preparation method provided by the invention, the high-purity lithium sulfide is prepared by a one-pot method, the liquid sulfur is used as a reaction raw material and a reaction solvent, and the whole reaction process does not need to use an organic solvent; according to the method, the lithium salt conversion rate can reach 99% or above, and the purity of the obtained lithium sulfide can reach 99.99% or above; compared with the prior art, the reaction temperature is lower, and low energy consumption and high conversion rate are both considered.

The invention provides a method for reducing the rubber crack propagation rate and a tire, and relates to the technical field of tire rubber.The method for reducing the rubber crack propagation rate comprises the steps that the maximum tearing energy in an application scene is obtained; determining the addition amount of organic polysulfide and sulfur in a vulcanizing agent according to the maximum tearing energy; and mixing the vulcanizing agent with the raw materials to obtain the target rubber material. When the maximum value of the tearing energy is large, the organic polysulfide is added into the sulfur, the organic polysulfide contains a plurality of thioalkyl chain segments, and in the vulcanization process, flexible alkyl chains can be connected into rubber macromolecules to form a composite cross-linked network structure which is more stable and higher in strength, so that the breaking tensile strength and the tearing strength of tire rubber are improved, and the service life of the tire rubber is prolonged. And the expansion rate of cracks can be reduced while bearing relatively high tearing energy, so that the service life is prolonged.

The present invention belongs to the technical field of desulfurization activated carbon regeneration, and relates to a blast furnace gas desulfurization activated carbon regeneration process and device, the regeneration device includes a washing and extraction tank, a regeneration reactor, a gas detection and analysis system, an automatic control system, a temperature monitoring system, and a deoxygenation reactor; the regeneration process includes S1, washing and extraction, S2, heating regeneration: according to the sulfur content of the outlet gas of the regeneration reactor, the heating temperature is adjusted by gradient, and the temperature range of the regeneration reactor is controlled: 150-300°C, and the temperature gradient is 30-50°C; S3, gas circulation, air oxidation, so that elemental sulfur is precipitated from polysulfide. The regeneration process of the present invention has a small carbon loss rate, increases the number of regenerations, and further reduces costs; the temperature of the thermal regeneration process is 150-300°C, the regeneration temperature is low, and the regeneration temperature can be adjusted according to the outlet gas concentration gradient, reducing energy consumption, and at the same time ammonia resources can be recycled, reducing the amount of solution used and the amount of waste liquid discharged, and the regeneration process can obtain elemental sulfur with economic value.

The invention discloses a process for directly synthesizing battery-grade lithium sulfide, which comprises the following steps: enabling metal lithium and sulfur to directly react in an inert gas atmosphere under the conditions of 30-350kPa and 945-1320 DEG C to generate a reaction product A containing lithium sulfide and lithium polysulfide; the molar ratio of metal lithium to sulfur is 1: (15-32); reducing the temperature of the reaction product A to 390-705 DEG C, carrying out countercurrent contact reaction on the reaction product A and hydrogen at 20-65 DEG C, and converting lithium polysulfide into lithium sulfide to obtain a reaction product B; and cooling and crushing the reaction product B to obtain the battery-grade lithium sulfide. The method is low in raw material cost, high in product purity and capable of fully recovering heat energy.

The invention provides a lithium-sulfur battery abnormal heating diagnosis method and system based on deep learning, and belongs to the technical field of lithium-sulfur battery safety monitoring. According to the method, an enhanced temperature difference sequence is constructed based on temperature and voltage detection data, a temperature state sequence is modeled, and continuous dynamic representation of thermal behaviors is realized; a double-path gating mechanism is designed, a global temperature rise suppression gate is utilized to capture the overall temperature rise trend, and an abnormal temperature rise sensitive gate is combined to focus local violent fluctuation, so that normal charging and discharging temperature rise interference is effectively suppressed, and temperature abnormal probability distribution is output; meanwhile, according to the interval where the current SOC is located, a corresponding voltage compensation function is selected, original voltage data are corrected point by point, a double-group long and short time memory network is designed to extract voltage platform drift characteristics, the perception capability of abnormal drift caused by the polysulfide effect is enhanced, and finally a comprehensive risk index is generated. And when the lithium-sulfur battery is under the polysulfide shuttle effect, the battery heating abnormity identification accuracy and robustness are obviously improved.

The invention discloses a sulfur disproportionation-mediated low-temperature high-efficiency low-carbon denitrification and synchronous ammonium recovery method for sewage, belongs to the field of sewage treatment, and aims to solve the problems that an existing autotroph denitrification process cannot adapt to water quality fluctuation and seasonal variation and is poor in engineering applicability. Polyculture denitrification and elemental sulfur disproportionation (SD) are used as an effective enhanced denitrification scheme and are applied to a low-temperature SDAD system of actual sewage. Sulfide and polysulfide generated in situ through elemental sulfur disproportionation reaction and low-concentration sodium acetate under the polyculture condition are used as supplementary electron donors, so that the denitrification rate is remarkably increased. The process of reducing dissimilatory nitrate into ammonium (DNRA) in the SD-MixBNR system is beneficial to emission reduction of greenhouse gases while realizing ammonium recovery. According to the method, the SD-MixBNR system can be promoted to be widely applied to actual engineering projects under the carbon neutralization background, and the stability and adaptability of the SD-MixBNR system in the face of various water quality fluctuations and seasonal changes are enhanced.

The invention is applicable to the technical field of carbon nanotube materials, and provides a cobalt-selenium co-doped carbon nanotube and a preparation method and application thereof, and the preparation method comprises the following steps: adding cobalt nitrate hexahydrate and a carbon nanotube into a methanol solution to obtain a solution A; dissolving 2-methylimidazole in a methanol solution to obtain a solution B; mixing the solution A and the solution B to form a purple precipitate, separating and washing the purple precipitate, and performing vacuum drying to obtain a ZIF-67 (at) CNT precursor; and putting the ZIF-67 (at) CNT precursor and selenium powder into a tubular furnace, raising the furnace temperature and preserving heat under argon flow, and then cooling to room temperature to obtain the Co-CoSe (at) CNT. According to the invention, a diatomic cobalt (Co) and selenium (Se) co-doped carbon nanotube (CNT) material is adopted as a main body material of sulfur, through a synergistic effect, the chemical adsorption capacity of the electrode material is remarkably enhanced, polysulfide is effectively captured, and excellent physical barrier performance is provided, so that the shuttle effect is further inhibited, and the long cycle life of the lithium-sulfur battery is prolonged.

The invention discloses a molybdenum carbide / nitrogen-doped carbon composite material and a preparation method and application thereof, and belongs to the technical field of new energy materials and devices. The preparation method comprises the following steps: uniformly mixing ammonium molybdate, glucose and g-C3N4, and carrying out hydrothermal and high-temperature calcination treatment to obtain a composite material (Mo2C / NC) in which a nano Mo2C electrocatalyst is dispersed and distributed on a nitrogen-doped carbon matrix. The nitrogen-doped carbon in the composite material has a hierarchical porous structure, so that the electrolyte permeation and ion transmission capabilities are enhanced; the nitrogen-doped active sites not only enhance the adsorption performance of the porous carbon on polysulfide, but also improve the catalytic activity by optimizing the coordination structure of Mo2C; mo2C can chemically adsorb and efficiently catalyze reversible conversion of polysulfide, and the utilization rate of active substances is increased. When the composite material is used as a positive electrode additive of a lithium-sulfur battery, dissolution and shuttling of polysulfide can be effectively inhibited, so that the battery has high specific capacity, rate capability and excellent cycle reversibility.

The invention relates to a solid-phase preparation method and application of battery-grade lithium sulfide, and the preparation method comprises the following steps: (1) firstly, adopting industrial-grade lithium carbonate as a raw material, and carrying out pretreatment purification to remove sodium-calcium-magnesium metal ion impurities; (2) carrying out ball-milling mixing on the purified lithium carbonate raw material and sulfur powder, and carrying out low-temperature melting pre-sintering; (3) performing primary high-temperature calcination on the lithium carbonate and sulfur powder mixture under a protective atmosphere to synthesize a lithium sulfide crude product; (4) carrying out secondary high-temperature calcination on the lithium sulfide crude product in a protective atmosphere to remove excessive sulfur impurities and lithium polysulfide impurities so as to obtain purified lithium sulfide; and (5) carrying out ball milling and crushing on the obtained lithium sulfide, and screening to obtain the battery-grade lithium sulfide with different particle sizes. According to the preparation method, a high-temperature solid-phase synthesis method is adopted, and low-temperature melting pre-sintering and high-temperature two-step calcining methods are adopted, so that reaction byproducts are gas and are easy to remove, production and preparation of high-purity battery-grade lithium sulfide can be realized, and the product has excellent electrochemical performance.

The invention discloses a thermal interface material based on elastomer glass and a preparation method thereof. The thermal interface material is prepared from the following raw materials: a diglycidyl ether-terminated liquid polythioether prepolymer, methyl tetrahydrophthalic anhydride, ethylene glycol diglycidyl ether, a catalyst and a heat-conducting filler. According to the invention, the highly vertical orientation of the heat-conducting filler is realized through a process of combining hot pressing and stack welding, and the heat-conducting filler has an extremely high heat conductivity coefficient in the vertical direction. The Rc of the thermal interface material is much lower than that of a commercial thermal interface material adopting a traditional silicon matrix, and the thermal interface material has a spontaneous contact behavior on the surface of the substrate.

The invention discloses a three-dimensional multi-interface heterostructure lithium-sulfur battery interlayer, a preparation method thereof and a lithium-sulfur battery, and the preparation method comprises the following steps: placing acidified carbon cloth in a mixed solution of cobalt nitrate, nickel nitrate and hexamethylenetetramine for primary hydrothermal reaction to prepare NiCo2O4 (at) CC; the NiCo2O4 (at) CC is placed in a mixed solution of nickel chloride and sodium molybdate, a secondary hydrothermal reaction is carried out, and NiMoO4 (at) NiCo2O4 (at) CC is obtained; according to the preparation method, NiMoO4-coated NiCo2O4-coated CC is subjected to thermal reduction annealing in a mixed atmosphere of hydrogen and argon, the three-dimensional multi-interface heterostructure lithium-sulfur battery interlayer is prepared, active sites of the three-dimensional heterostructure are increased, the oxidation-reduction reaction efficiency under high sulfur loading capacity is improved, the nano-particle anchored amorphous nanosheets form the multi-interface heterostructure, and the performance of the lithium-sulfur battery is improved. Good chemical adsorptivity and catalytic conversion on polysulfide in the battery are realized, and the cycle life of the battery is prolonged.

The invention provides a Mn-based metal organic framework derived Mn2O3 / Mn3O4 heterojunction material as well as a preparation method and application thereof, and belongs to the field of nano material preparation methods and electro-catalysis cross application. The preparation method comprises the following steps: S10, reacting manganese salt, a surfactant and a benzoic acid compound in a solvent to obtain a Mn-based metal organic framework material; s20, calcining the Mn-based metal organic framework material in an inert atmosphere to obtain a carbonized product; and S30, flattening the carbonized product, and calcining the flattened carbonized product in an air atmosphere to obtain the Mn-based metal organic framework derived Mn2O3 / Mn3O4 heterojunction material. The method can be applied to renewable energy sources, is simple in process, universal in preparation condition, high in yield, green and environment-friendly, stable in product morphology and excellent in catalytic activity, shows excellent activity and electrochemical performance in catalysis of lithium polysulfide conversion of a cathode of a lithium-sulfur battery, and is also suitable for medium-scale industrial production.

The invention relates to a dual-rare earth metal catalytic nano material, a diaphragm and a preparation method and application thereof. The preparation method comprises the following steps: carrying out hydrothermal reaction on an aqueous solution containing a carbon source, a hard template, a graphene oxide dispersion liquid, a nitrogen source, a phosphorus source, cerium salt and neodymium salt; then carrying out centrifugal separation to obtain a precipitate, and generating a precursor containing Ce and Nd rare earth bimetallic modified nitrogen and phosphorus doped graphene coated microspheres; and carrying out chemical etching on the precipitate after heat treatment to obtain the dual-rare earth metal catalytic nano material (HCS-coated NPrGO / CeNd). The HCS-coated NPrGO / CeNd can be used as a modification material of a lithium-sulfur battery diaphragm, not only can catalyze the conversion of polysulfide, but also can inhibit the shuttle effect of the polysulfide, so that the lithium-sulfur battery has relatively high capacity under high-rate charge and discharge, and has relatively low capacity fading rate in a high-rate long-cycle test.

The invention provides a preparation method of a heteroatom-doped mesoporous carbon nanotube material and application of the heteroatom-doped mesoporous carbon nanotube material in a lithium-sulfur battery. The preparation method comprises the following steps: S1, preparing a polyphosphazene nanotube by utilizing a self-template method; s2, preparing PZS coated SiO2 by adopting a sol-gel method; s3, NPS-C coated SiO2 is prepared through carbonization; and S4, adding the NPS-C-coated SiO2 powder into an etching solution, stirring, centrifuging, washing, and finally performing vacuum drying at room temperature to obtain the NPS-C material. The NPS-C obtained by carbonizing the precursor prepared on the basis of a self-template method and a sol-gel method has excellent conductivity, the mesoporous hollow structure can be used as a sulfur species packaging framework to inhibit large volume fluctuation in the circulation process, heteroatoms can adsorb and fix polysulfide to effectively inhibit the shuttle effect, and the performance of the NPS-C is improved. And a new thought is opened up for exploration and design of the high-performance electrode material of the lithium-sulfur battery.

A method of producing a carbonate bonded article includes preparing a reactive mixture having a particulate mineral source and an aqueous source, and reacting the reactive mixture with carbon dioxide to form a mineral matrix including carbonates. The particulate mineral source includes a leachable compound, the leachable compound including one or more elements selected from: As, Ba, Cd, Cr, Co, Cu, F, Hg, Mo, Mn, Ni, Pb, Sb, Se, V, and Zn. The reactive mixture includes a reducing agent, where the reducing agent includes one or more of a sulfide, disulfide, and polysulfide compound that reacts with the particulate mineral source. The pH of the reactive mixture is at least 10.

The invention discloses an MXene composite material as well as a preparation method and application thereof, and belongs to the technical field of composite materials. The MXene composite material provided by the invention comprises an anthraquinone based covalent organic framework and aminated MXene, the anthraquinonyl covalent organic framework is covalently connected to the surface of the aminated MXene. The MXene composite material is obtained through covalent connection of an anthraquinone covalent organic framework and aminated MXene, on one hand, the covalent connection of the covalent organic framework and the MXene can reduce an electron transfer energy barrier, and therefore the utilization rate of redox active groups in the covalent organic framework is increased; on the other hand, MXene can improve the overall conductivity of the material, anthraquinone groups in the anthraquinone covalent organic framework can be combined through lithium bonds and can be converted into lithium polysulfide, and the MXene composite material is beneficial to preparation of lithium-sulfur batteries with excellent electrochemical performance.

The invention discloses a preparation method and application of an in-situ curing polymer electrolyte for a lithium-sulfur battery, and belongs to the technical field of solid-state batteries, the preparation method comprises the following steps: stirring and mixing an initiator, a polymeric monomer, a lithium salt and an additive to obtain a uniform precursor solution; and 2, dropwise adding the precursor solution obtained in the step 1 to the surface of a diaphragm, and carrying out thermal initiation polymerization to obtain the polymer electrolyte. According to the preparation method and application of the in-situ curing polymer electrolyte for the lithium-sulfur battery, through an in-situ curing process, shuttling of polysulfide is inhibited, the interface resistance between an electrode and the electrolyte is reduced, and the ion transmission capacity is improved; the nitrate ester additive is added into the electrolyte, so that a nitrogen-rich stable interface layer with high ionic conductivity is formed on the surface of the lithium negative electrode under the condition that the polymerization state of the electrolyte is not damaged, the growth of lithium dendrites is effectively inhibited, and the assembled solid polymer lithium-sulfur battery keeps excellent performance.

The invention belongs to the technical field of electrochemical energy storage and electrocatalysis, and provides a modified electrode for in-situ growth of copper sulfide, a preparation method of the modified electrode and a flow battery. The preparation method comprises the following steps: (1) doping sulfur atoms and fluorine atoms on a substrate material by adopting a plasma cleaning method to obtain a doped substrate; (2) spraying a copper ion solution on the doped substrate, fully wetting, spraying a sulfur ion solution on the surface of the wetted doped substrate, and reacting; and (3) cleaning and drying the doped substrate to obtain the modified electrode for in-situ growth of copper sulfide. The low-cost and high-performance modified electrode for in-situ growth of copper sulfide has the advantages of high conductivity, specific surface area, electrochemical activity, catalytic performance and stability, improvement of polysulfide redox reversibility and the like, and can be applied to a sulfur-based flow battery system taking polysulfide as an active substance.

The invention discloses a preparation method and application of a two-dimensional composite material. The preparation method comprises the following steps: adding MXene into formamide, carrying out ultrasonic dispersion to obtain an MXene formamide dispersion liquid, then adding MgAl LDH into the MXene formamide dispersion liquid, carrying out magnetic stirring, washing with absolute ethyl alcohol, and carrying out vacuum drying to obtain a two-dimensional composite material which is marked as MgAl LDH / MXene. The two-dimensional composite material is used for a lithium-sulfur battery diaphragm barrier layer so as to inhibit the shuttle effect of polysulfide. The preparation method is simple and environment-friendly, and the prepared MgAl LDH / MXene two-dimensional composite material is high in specific surface area, has strong affinity to polysulfide, can promote rapid transmission of lithium ions, can provide an instant electron conduction way for adsorbed polysulfide, is applied to a diaphragm barrier layer of a lithium-sulfur battery, and has a good application prospect. The wettability of the electrolyte on the diaphragm and the conversion of polysulfide are enhanced, the problem of volume expansion in the cycle process of the lithium-sulfur battery is relieved, and the redox reaction kinetics is accelerated.

According to the cobalt-doped molybdenum disulfide lithium-sulfur battery composite positive electrode material, the preparation method and the application, a cobalt-doped stable molybdenum disulfide defect structure composite nitrogen-doped graphene material is prepared by combining a solvothermal method and an annealing technology, and the process is mature; the method is simple, and the composite positive electrode material with high sulfur content is easy to obtain. According to the lithium-sulfur battery composite sulfur positive electrode material disclosed by the invention, the strong chemical adsorption effect and catalytic conversion effect of the cobalt-doped stable molybdenum disulfide defect structure composite nitrogen-doped graphene carrier on polar lithium polysulfide are utilized, so that the diffusion of the lithium polysulfide in an ether electrolyte is inhibited, and the electrochemical reaction kinetics is improved; therefore, the shuttling effect is slowed down, and the lithium-sulfur battery has the characteristics of high capacity and long service life.

The invention discloses a composite lithium sulfide positive electrode material as well as a preparation method and application thereof, and belongs to the field of lithium-sulfur batteries. A carbon source and metal salt are subjected to a one-step calcination method, urea reacts with nickel salt and iron salt to generate a nickel nitride and iron nitride compound, glucose and urea generate nitrogen-doped multi-stage porous carbon under the action of a sodium chloride template, and a nickel nitride / iron nitride compound and a nitrogen-doped multi-stage porous carbon composite material are obtained and serve as precursor materials. The preparation method comprises the following steps: mixing lithium sulfide with N-methyl pyrrolidone to prepare lithium sulfide slurry; and immersing the prepared precursor material into the lithium sulfide slurry, and drying to obtain the composite lithium sulfide positive electrode material. Nickel nitride and iron nitride in the material are used as double catalysts and have a synergistic effect to accelerate the redox reaction of lithium sulfide / lithium polysulfide. In addition, the nitrogen-doped multi-stage porous carbon structure can effectively bear lithium sulfide and lithium polysulfide and relieve volume expansion.

The present invention provides a composite positive electrode for an all-solid-state lithium-sulfur battery and a method for preparing the same, belonging to the technical field of positive electrode materials for lithium-sulfur batteries. The composite positive electrode comprises a sulfur / carbon composite material with a gradient surface modification of phosphorus polysulfide and a solid electrolyte. The composite material comprises porous carbon, sulfur, and phosphorus polysulfide, with the sulfur loaded on the outer surface and / or in the pores of the porous carbon, and a phosphorus polysulfide layer with a gradient distribution of a specific structure on the surface of the sulfur / carbon composite. The present invention utilizes the sulfur / carbon composite material with a gradient surface modification of phosphorus polysulfide as a positive electrode material for an all-solid-state lithium-sulfur battery, effectively increasing the active sulfur content and specific capacity of the composite positive electrode layer. The composite positive electrode of the present invention can have an active sulfur content exceeding 50 wt%, a specific capacity calculated based on elemental sulfur exceeding 1300 mAh / g, and a specific capacity based on the total mass of the composite positive electrode exceeding 650 mAh / g. Furthermore, the composite positive electrode exhibits excellent cycle and rate performance.

A lithium-sulfur battery including an anode, a cathode, a separator, and an electrolyte dispersed throughout the lithium-sulfur battery is provided. The anode may output lithium ions. The cathode may be positioned opposite to the anode and have an overall porosity as defined by multiple non-hollow carbon spherical (NHCS) particles joined together to form tubular NHCS particle agglomerate. Pores may be associated with the overall porosity of the cathode and interspersed uniformly throughout the NHCS particles. In some aspects, each pore having a diameter between 1 nm and 10 nm; and each tubular NCHS agglomerate has a length between 5 micrometers (μm) and 35 μm. Interconnected channels defined in shape by the NHCS particles may be joined to each other and the pores, where some interconnected channels may be pre-loaded with an elemental sulfur and retain polysulfides (PS). Retention of the polysulfides may be based on some NHCS particles.

The invention discloses a sulfur positive electrode material based on an amorphous crystalline cobalt phosphide / porous carbon composite carrier and a preparation method and application of the sulfur positive electrode material, the amorphous crystalline cobalt phosphide / porous carbon composite carrier is used as a conductive carrier, and the amorphous crystalline cobalt phosphide / porous carbon composite carrier is fused and compounded with active sulfur to obtain the composite sulfur positive electrode material for a lithium-sulfur battery. According to the present invention, the hierarchical porous structure is provided, the high specific surface and the high pore volume provide the sufficient sulfur loading space, the three-dimensional carbon network structure provides the excellent electron conduction and ion diffusion ability, the chemical adsorption can be well achieved, the reversible conversion of the polysulfide can be efficiently catalyzed, and the utilization rate of the active substance can be improved; the catalytic activity can be optimized, the electro-catalytic performance of the catalyst can be improved, dissolution and diffusion of polysulfide can be physically limited, and meanwhile electrode volume expansion in the charging and discharging process is relieved; the sulfur positive electrode material is applied to a lithium-sulfur battery, can effectively inhibit dissolution and shuttling of polysulfide, and shows excellent electrochemical performance.

The invention belongs to the technical field of electrochemistry, and discloses a pi-d conjugated covalent organic framework material, and a preparation method thereof comprises the following steps: adding 2, 5-hydroxyterephthalic acid, 2, 3, 5, 6-tetra (amino) p-benzoquinone and nickel acetate tetrahydrate into a container, then adding N-methyl pyrrolidone, carrying out ultrasonic treatment for 0.5 h, transferring into a hydrothermal reaction kettle, carrying out a sealed reaction for 2-5 days, and carrying out vacuum drying to obtain the pi-d conjugated covalent organic framework material. And after the reaction is finished, naturally cooling to room temperature, filtering, collecting, washing and performing vacuum drying on the obtained precipitate to obtain the pi-d conjugated covalent organic framework material. The covalent organic framework material disclosed by the invention is rich in N / O chemical adsorption sites and Ni < 2 + > catalytic sites, so that shuttling of polysulfide can be effectively inhibited; on the other hand, catalytic conversion of polysulfide is promoted, the reaction kinetics of the lithium-sulfur battery is further accelerated, and compared with a traditional covalent organic framework, the conductivity is greatly improved, and the electron transmission capacity is improved.

The invention provides a layered porous WB (at) WO3 heterojunction nanosheet, a preparation method thereof and application of the nanosheet in a lithium-sulfur battery diaphragm, tungsten boron aluminide is etched by using alkali liquor to remove an Al layer in a phase to obtain a two-dimensional layered tungsten boride precursor, and then an in-situ oxidation reaction is performed to generate a WB (at) WO3 heterojunction material. Compared with the prior art, the preparation method disclosed by the invention is simple to operate, green and pollution-free to the environment, good in repeatability and easy to popularize, and the obtained porous layered structure is obtained. The precursor can be directly prepared by stirring, and the WB-coated WO3 heterojunction porous nanosheet is prepared simply and quickly by regulating and controlling the temperature. The method is used for constructing a functional modification layer on the surface of the diaphragm, so that the initial capacity of the lithium-sulfur battery is remarkably improved, the key problem of polysulfide shuttling is effectively solved, and the cycle life of the battery is comprehensively prolonged.

The invention discloses a preparation method and application of a self-supporting positive electrode material of a lithium-sulfur battery, and the preparation method comprises the following steps: firstly, obtaining self-supporting in-situ nitrogen-doped carbon nanofiber (PCNF) with a porous structure by utilizing electrostatic spinning and carbon heat treatment, and then soaking the PCNF in an ethanol solution of Co-ZIF-8, and calcining to obtain the cobalt / zinc oxide-nitrogen doped porous carbon modified carbon nanofiber material (Co / ZnO-NC (at) PCNF). The self-supporting positive electrode material prepared by the method does not need to use a binder, has good mechanical properties, and provides a three-dimensional conductive network and a smooth ion migration channel, and then Co / ZnO-NC has dual effects of chemical adsorption and catalytic conversion on polysulfide, so that the shuttle effect is effectively relieved, and the performance of the lithium-sulfur battery is improved.

The present invention discloses a highly active cathode material catalyst for lithium-sulfur batteries and a preparation method thereof. The catalyst comprises a flaky nitrogen-doped carbon-based support and platinum metal nanoclusters uniformly embedded on the support surface. The platinum metal nanoclusters are 1-10 nm in size and have a mass ratio of 10-20% on the support. The catalyst is then processed through molten sulfur to serve as the cathode material for lithium-sulfur batteries. The catalyst is prepared by physical mixing a cyanamide compound and an organometallic molybdenum salt, or by adding a defective carbon material, and then directly carbonizing the material in an inert atmosphere in a tube furnace. The high-surface-weight-weight-weight-weight-weight-weight-sheet flaky nitrogen-doped carbon conductive material, with uniform distribution of platinum metal nanoclusters, physically adsorbs and chemically catalyzes polysulfides formed during the charge and discharge process on the positive electrode side of the lithium-sulfur battery, capturing the polysulfides and eliminating the "shuttle effect" during charge and discharge, ultimately improving the electrochemical performance of the electrode material. The initial discharge specific capacity can reach up to 1314.2 mAh / g, and after 100 cycles, the specific capacity decay is only 20%. This catalyst material has broad application prospects for lithium-sulfur batteries.

The invention discloses a preparation method and application of a sulfur-doped metal monatomic loaded porous carbon material. Metal ions and sulfonic acid groups are utilized to form stable coordination bonds, the stable coordination bonds are confined in a zeolite imidazole-8 three-dimensional network porous structure, and the sulfur-doped metal monatomic loaded porous carbon material is obtained through pyrolysis. The material is in a dodecahedron shape, the particle size is 100-1000 nm, and the mass percent of metal monatomic is 0.1%-10%. In addition, the electronic structure of the active site of the catalyst is adjusted through sulfur doping, the monatomic adsorption and catalysis capability is improved, polysulfide shuttling is relieved, the electrode conversion reaction kinetics is improved, and the high-performance lithium-sulfur battery is achieved.

The invention belongs to the field of nano catalytic materials and lithium-sulfur batteries, and particularly relates to a nitrogen-doped carbon-coated cobalt zinc carbide catalyst material as well as a preparation method and application thereof. The preparation method comprises the following steps: stirring cobalt potassium cyanide, cobalt salt and zinc salt, standing and aging to obtain a precursor, and carbonizing the precursor at high temperature to obtain the catalyst material. The catalyst material comprises cobalt-zinc carbide nanoparticles and an ultrathin nitrogen-carbon structure coating the surfaces of the cobalt-zinc carbide nanoparticles, and the carbon-nitrogen structure can stabilize the internally coated cobalt-zinc carbide nanoparticles and ensure the effective action of lithium polysulfide and cobalt-zinc carbide metal active sites; meanwhile, the catalyst material has a hierarchical porous structure and rich surface active sites, can effectively capture dissolved lithium polysulfide, and can realize efficient catalytic conversion of lithium polysulfide, so that the catalyst material can greatly improve the electrochemical performance of the lithium-sulfur battery as a diaphragm modification functional material of the lithium-sulfur battery.