655 results about "Pyrophosphate" patented technology

The present invention relates to a sodium-ion battery material, and specifically relates to a sodium ferric phosphate pyrophosphate composite material, and a preparation process, evaluation method and process optimization method therefor and the use thereof. The sodium ferric phosphate pyrophosphate composite material has a spinel-type NaFePO4 phase; and in an XRD diffraction pattern obtained by subjecting the sodium ferric phosphate pyrophosphate composite material to XRD diffraction using CuKα radiation, there are a characteristic diffraction peak T of sodium ferric phosphate pyrophosphate and a characteristic diffraction peak O of spinel-type NaFePO4 at 2θ of 33.6±0.2° and 32.8±0.2°, respectively, the peak intensities thereof are respectively IT and IO, and the diffraction peak intensity ratio Ir is equal to IT / IO, wherein 6.19≤Ir≤13.

The invention discloses a modified carbon-coated sodium manganese ferric phosphate pyrophosphate / sodium ferric phosphate pyrophosphate positive electrode material as well as a preparation method and application thereof, and relates to the technical field of new energy materials. The preparation method comprises the following steps: preparing MnFe-MOF from a manganese source, a first iron source and a first organic ligand under a hydrothermal reaction; a second iron source, the MnFe-MOF and a second organic ligand are subjected to a hydrothermal reaction, and MnFe-MOF / Fe-MOF is obtained; uniformly mixing with a sodium source and a phosphorus source, and sintering to obtain a positive electrode material; and carrying out high-temperature gas-phase etching treatment to obtain the fluorine-doped carbon-coated modified sodium manganese ferric phosphate pyrophosphate / sodium ferric phosphate pyrophosphate positive electrode material. The material disclosed by the invention has a coating modified structure, so that an interface side reaction caused by direct contact between sodium ferromanganese phosphate and an electrolyte can be effectively avoided, a manganese dissolution phenomenon is reduced, and the structural stability of the material is improved; and meanwhile, the material has high conductivity, excellent structural stability, excellent long cycle life and excellent rate capability.

A positive electrode material, and a preparation method therefor and the use thereof. The positive electrode material has a core-shell structure, wherein a core part comprises a carbon-coated Cu2+-doped iron-based phosphate sodium-ion material, and a shell layer is CuO. The iron-based phosphate sodium-ion material is selected from ferric sodium pyrophosphate, ferric sodium phosphate or ferric sodium phosphate pyrophosphate. The preparation method for the positive electrode material comprises: mixing the carbon-coated iron-based phosphate sodium-ion material, a copper source and a first solvent, and then subjecting the mixture to first drying and first calcination.

The invention provides a Na / P double-site doped phosphoric acid ferric sodium pyrophosphate / carbon positive electrode active material and a preparation method and application of the Na / P double-site doped phosphoric acid ferric sodium pyrophosphate / carbon positive electrode active material. The material comprises a Na / P double-site doped ferric sodium pyrophosphate base material and a carbon coating layer coating the surface of the base material, the general formula of the base material is Na (4-x) MxFe3 (PO4) 2-y (QO4) y (P2O7), 0 lt, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 X is less than or equal to 0.4, 0lt; y < = 0.2; m is at least one of K, Li, Mg, Ca and Sr, and Q is at least one of Si, Ge, B and S; specific elements are introduced to the Na site and the P site to form a synergistic doping structure, so that the crystal structure and charge distribution are regulated and controlled, and the electrochemical performance of the material is further improved; the material disclosed by the invention is simple and convenient to prepare, wide in raw material source, suitable for electrochemical energy storage systems such as sodium ion batteries and the like, and excellent in rate capability and long in cycle life.

The invention relates to a preparation method of a nickel ion doped modified ferric sodium pyrophosphate positive electrode material, and belongs to the technical field of sodium ion battery positive electrode materials. The nickel ion doped modified ferric sodium pyrophosphate positive electrode material is prepared by adopting an integrated process system of liquid phase uniform mixing, spray granulation and precise segmented calcination. According to the process system, atomic-scale uniform doping of nickel ions and a specific microstructure of a precursor are realized through spray drying, and a plurality of inherent key technical problems of low electronic conductivity, low ion diffusion rate, impurity phase generation and the like of an NFPP material are solved together through a synergistic effect with a subsequent calcining process; furthermore, the discharge capacity of the ferric sodium phosphate pyrophosphate composite material at high rate is improved, so that the battery has relatively high cycling stability.

The invention belongs to the technical field of sodium ion batteries, and particularly relates to a sodium ferric pyrophosphate positive electrode material as well as a preparation method and application thereof. The invention provides a preparation method of a sodium ferric pyrophosphate positive electrode material, which comprises the following steps: (1) mixing an iron source, a sodium source, a phosphorus source and citric acid for the first time, and performing spray drying for the first time to prepare a first precursor with D50 of 10-12 [mu] m; performing secondary mixing on an iron source, a sodium source, a phosphorus source and citric acid, and performing secondary spray drying to prepare a second precursor with D50 of 3-5 microns; the iron source comprises a first iron source with D50 of 1.1-1.8 [mu] m and a second iron source with D50 of 0.3-0.8 [mu] m; the mass ratio of the first iron source to the second iron source is (0.3-0.5): (0.5-0.7); and (2) mixing the first precursor, the second precursor and sodium metaborate, and sintering to obtain the sodium ferric pyrophosphate positive electrode material. After the prepared pyrophosphate ferric phosphate sodium positive electrode material is prepared into a pole piece, the compaction density is proper, and the prepared battery is high in specific capacity and cycle performance.

The invention relates to the technical field of batteries, and discloses a high-compaction ferric sodium pyrophosphate positive electrode material and a preparation method thereof.The chemical formula of the positive electrode material is Na4Fe2.9VxTiyZrz (PO4) 2P2O7, 0.001 < = x < = 0.01, 0.002 < = y < = 0.01, and 0.001 < = z < = 0.01. The preparation method comprises the following steps that a sodium source, an iron source, a phosphorus source, a carbon source, a vanadium source, a titanium source and a zirconium source are weighed and mixed to be uniform, and a mixture is obtained; carrying out primary sanding treatment to obtain first sanding slurry, carrying out spray drying, and carrying out primary sintering treatment to obtain a pre-sintered material; adding a proper amount of carbon source into the pre-sintered material, and carrying out secondary sanding treatment to obtain a second ground material; and carrying out spray drying on the second grinding material, and carrying out secondary sintering treatment to obtain the positive electrode material. The high-compaction ferric sodium pyrophosphate positive electrode material provided by the invention has high compaction density and excellent rate capability and cycle performance, and can be used for preparing a sodium ion battery with high compaction density, high capacity and good rate capability and cycle performance.

The invention discloses application of iron ruthenium nano-enzyme in preparation of nucleic acid detection products, and belongs to the technical field of biological detection and nano-materials. The RIN has stable peroxidase-like (POD) activity, and can catalyze a chromogenic reaction between 3, 3 ', 5, 5'-tetramethyl benzidine (TMB) and hydrogen peroxide (H2O2). The catalytic activity of the nano-enzyme can be selectively inhibited by pyrophosphate (PPi) generated in a nucleic acid amplification reaction, so that visual colorimetric analysis on whether target nucleic acid exists or not is realized. In combination with a polymerase chain reaction (PCR) system, the invention constructs a new nucleic acid detection strategy which does not need fluorescence labeling, is simple and convenient to operate and has high sensitivity. Through verification, the system can be widely applied to rapid on-site screening and visual interpretation of related nucleic acid of drug-resistant pathogens (such as ESKAPE flora) and the like, and has a good application prospect.

The invention belongs to the field of battery materials, and discloses a PEO-based composite solid electrolyte and a preparation method and application thereof, the PEO-based composite solid electrolyte comprises double transition metal-based pyrophosphate, PEO and an electrolyte lithium salt; wherein the molecular formula of the double transition metal-based pyrophosphate is MaNb (P2O7) c, M is any one or two of Fe and V, N is any one or two of Pb and Cd, a is greater than or equal to 1 and less than or equal to 2, b is greater than or equal to 1 and less than or equal to 5, and c is greater than or equal to 1 and less than or equal to 4. By applying the double-transition-metal-based pyrophosphate to the solid electrolyte, the suitability of the solid electrolyte and a positive electrode material with the charging cut-off voltage of 4V or above is improved, and the application range of the solid electrolyte in a battery system with high energy density and long cycle life and a functional energy storage device is widened; and the electrochemical capacity, the structural stability and the ionic conductivity of the battery can be improved.

The invention belongs to the field of biosynthesis, and in particular relates to LBD (Levandanenediol Pyrophosphate) synthase and engineered yeast for producing sclareol. In order to solve the problem that in the prior art, the sclareol biosynthesis yield is generally low, LSLPPs mutant containing at least one mutation of D730L, D374L, N674L or G379M is obtained by performing mutation and optimization on LSLPPs pyrophosphate synthase, and the mutant is used for sclareol synthesis. Meanwhile, in order to solve the problem of genetic instability caused by free plasmid expression of part of saccharomyces cerevisiae strains, a sclareol synthesis pathway is constructed in a yeast genome, and meanwhile, an acetyl coenzyme A synthesis pathway, an MVA pathway and a sclareol synthesis pathway are enhanced; chassis bacteria for synthesizing sclareol are modified in a manner of knocking out part of transcription inhibition factors, and the yield of a 5L fermentation tank reaches 26.11 g / L and is greatly improved compared with the prior art.

The invention belongs to the field of flame-retardant materials, and particularly relates to a flame-retardant wood-plastic composite material and a preparation method thereof. Raw camphorwood powder is subjected to alkali treatment and hyperbranched silicon dioxide grafting treatment and then is subjected to melt blending with polypropylene, piperazine pyrophosphate and melamine phosphate, and the wood-plastic composite material with the intumescent flame-retardant effect is prepared. Limit oxygen index, vertical combustion, thermogravimetry, cone calorimetry and other tests show that the prepared wood-plastic composite material has excellent flame retardance, the limit oxygen index can reach 36.8%, the vertical combustion test reaches the V-0 grade, the total smoke release amount is reduced to 45.3% of that of raw materials, the flame retardance, smoke suppression and other performance are remarkably improved, and the wood-plastic composite material has good application potential.

The invention provides a uracil production strain and a construction method and application thereof.According to the strain, on an E.coli UR14 genome by means of a CRIPSR / Cas9 gene editing technology, firstly, psuG genes, preTA genes, rutA genes and upp genes are knocked out, so that decomposition of uracil is blocked; then, a uridine phosphorylase gene udp and a pyrimidine-5 '-nucleotide nucleotidase gene ppnN are subjected to overexpression, and synthesis and accumulation of uracil are synergistically enhanced; and finally, overexpression of the ribose phosphate mutase gene pgm further enhances the conversion of a by-product ribose phosphate 1-precursor 5-ribose phosphate 1-pyrophosphate and improves the carbon utilization rate, and the obtained strain has good genetic stability and high fermentation yield, can stably produce uracil, and has wide application prospects.

The invention provides a copper-nickel alloy foil and a preparation method and application thereof, and belongs to the technical field of lithium ion battery negative electrode current collectors, and the preparation method comprises the following steps: preparing a copper-nickel composite electrolyte, and adding a coordination agent, a pH buffer agent and an additive into the copper-nickel composite electrolyte to obtain a mixed electrolyte; the coordination agent comprises a main coordination agent and an auxiliary coordination agent, and the main coordination agent comprises at least one of trisodium citrate, potassium sodium tartrate and sodium pyrophosphate; the auxiliary coordination agent comprises at least one of ammonia water, glycine and triethanolamine; and a cathode and an anode are placed in the mixed electrolyte, the pH of the mixed electrolyte is controlled to be 6-10, direct current is applied for electrochemical deposition, and the copper-nickel alloy foil is obtained. According to the method, the alkalescence system is adopted, the main coordination agent and the auxiliary coordination agent are used, full coordination of free Cu < 2 + > and Ni < 2 + > is achieved, precipitation is avoided, the hydrogen evolution phenomenon is greatly reduced, and the alloy foil quality is improved.

The invention provides a sodium ferric phosphate pyrophosphate-based composite material as well as a preparation method and application thereof, and relates to the technical field of sodium ion battery electrode materials. The composite material is of a core-shell structure and sequentially comprises a base material, a heterogeneous interface layer and a coating layer from inside to outside, the chemical formula of the base material is Na4Fex( PO4) 2P2O7, the heterogeneous interface layer is iron-based phosphide nanoparticles distributed on the surface of the base material, and the coating layer is a carbon layer; the iron-based phosphide is prepared from at least one of FeP and Fe2P; 3 < = x < = 4; iron-based phosphide nanoparticles are generated on the surface of the ferric sodium phosphate pyrophosphate material through in-situ reduction, a tightly-combined heterogeneous interface network is formed, the electron and ion transmission performance of the material is remarkably improved, and the rate performance is improved; the preparation method is simple and easy to implement on a large scale.

The preparation method comprises the following steps: (1) weighing a sodium source, an iron source, a phosphorus source and a carbon source, quickly and uniformly mixing, and then pre-sintering at low temperature to obtain a precursor; wherein the low-temperature presintering comprises two stages, in the first stage, the temperature is increased to 60-150 DEG C and kept for 1-3 h, and in the second stage, the temperature is increased to 200-350 DEG C and kept for 1-8 h; and (2) adding a carbon source into the precursor to prepare slurry, sanding the slurry, carrying out centrifugal spray drying, and carrying out high-temperature sintering to obtain the ferric sodium pyrophosphate positive electrode material. The precursor of the high-solid-content slurry can be prepared, the problem that the solid content of the slurry is low in the grinding stage of the sodium ferric pyrophosphate positive electrode material prepared by a solid-phase method is effectively solved, the solid content of the slurry is increased, the yield of the precursor is increased, the production cost is reduced, and meanwhile, the product quality is improved. The prepared ferric sodium pyrophosphate positive electrode material has relatively high compaction density, capacity and other performances, and the performance of the product is improved.

The embodiment of the invention provides a polyanionic positive electrode material and a preparation method thereof, a positive electrode plate, a secondary battery and an electric device, and belongs to the technical field of secondary batteries. The polyanionic positive electrode material is ferric sodium pyrophosphate, the polyanionic positive electrode material comprises primary particles and secondary spheres formed by the primary particles, and the primary particles comprise primary particles with the particle size Dv50 being d1 and primary particles with the particle size Dv50 being d2, d1gt; d2, the secondary sphere is of a core-shell structure, a core is of a porous structure, and a shell layer is of a compact structure. The polyanionic positive electrode material is relatively high in compaction density, and has the advantages of good cycle performance and good rate capability.

The invention discloses carbon-coated ferric sodium pyrophosphate as well as a preparation method and application thereof. The preparation method of the carbon-coated ferric sodium pyrophosphate comprises the following steps: 1) adding a phosphorus source, an iron source and a sodium source into an aqueous solution to obtain a mixed solution; dispersing a conductive agent into the mixed solution to obtain dispersion liquid; carrying out spray drying on the dispersion liquid to obtain a ferric sodium pyrophosphate precursor containing the conductive agent; 2) dissolving chitosan in an acetic acid aqueous solution to obtain a chitosan colloidal solution; then adding feather keratin into the chitosan colloidal solution, heating and stirring until the feather keratin is uniformly dispersed to obtain a dispersion liquid of double carbon sources; adding a conductive agent-containing ferric pyrophosphate sodium precursor into the double-carbon-source dispersion liquid, uniformly stirring and mixing, and heating and evaporating to dryness to obtain a carbon source-coated ferric pyrophosphate sodium precursor; and 3) carrying out heat treatment on the carbon source-coated ferric pyrophosphate sodium precursor in an inert atmosphere to obtain carbon-coated ferric pyrophosphate sodium.

The invention discloses sulfate-erosion-resistant metakaolin-slag-based geopolymer concrete, belongs to the technical field of concrete, and aims to solve the problems that the corrosion resistance of traditional silicate concrete is ineffective and the adaptability of conventional alkali-activated concrete is insufficient in a special environment. The concrete comprises the following components in parts by weight: 60-90 parts of a cementing material, 120-170 parts of aggregate, 15-30 parts of a composite activator, 2-8 parts of a function regulator and the like, the cementing material is prepared from nano TiO2 / KH-550 composite modified metakaolin, slag and silica fume-coal gangue powder-HAP composite powder; the aggregate comprises modified limestone macadam (soaked and dried by a sodium dihydrogen phosphate solution) and river sand; the composite exciting agent comprises water glass, sodium hydroxide, sodium pyrophosphate, propylene glycol and the like; the function regulator comprises superfine fly ash, a naphthalene water reducer, HPMC (Hydroxy Propyl Methyl Cellulose) and boric acid. Through the synergistic effect of the components, the sulfate corrosion resistance, the mechanical property and the environmental adaptation performance of the concrete are improved, and the concrete is suitable for engineering construction under the service environment of high-concentration sulfate and the like.

The invention provides an anti-erosion refractory material for calcination of an aluminum ash rotary kiln and a preparation method of the anti-erosion refractory material, and relates to the technical field of refractory materials. Comprising the following raw materials in percentage by mass: 20%-70% of flint clay with the particle size of 0-5mm, 5%-40% of synthetic mullite with the particle size of 0-5mm, 5%-20% of synthetic mullite powder with the particle size of 0-0.074 mm, 1%-20% of silica powder with the particle size of 0-0.074 mm, 1%-15% of synthetic material powder with the particle size of 0-0.074 mm and 1%-15% of clay with the particle size of 0-0.074 mm. According to the anti-erosion refractory material for calcination of the aluminum ash rotary kiln and the preparation method thereof, a high-viscosity glass phase is generated in situ, and a dynamic protection layer is formed on the surface of the refractory material to prevent permeation of harmful gas, so that the thickness of a metamorphic layer is reduced, damage to a refractory product is slowed down, and the service life is prolonged; through the synergistic effect of the silica powder and the synthetic powder, the refractory material can be sintered at a low temperature, and the production energy consumption is reduced.

The invention relates to a preparation method of a doped carbon material coated sodium ferric pyrophosphate positive electrode material, which comprises the following steps: S1, mixing a sodium source, an iron source, a phosphorus source, a carbon source and a dispersing agent which are respectively weighed according to a stoichiometric ratio to obtain a premix; wherein the molar ratio of sodium to iron to phosphorus in the sodium source, the iron source and the phosphorus source is 4: 3: 4; adding water of which the mass is 3-5 times that of the premix into the premix, and stirring and dispersing to obtain dispersion liquid; s2, transferring the dispersion liquid into a sand mill, and sanding until the granularity of solid particles is 0.1-0.8 mu m, so as to obtain slurry; and S3, carrying out spray drying on the slurry, and sintering powder generated by spray drying in an inert atmosphere furnace to obtain the doped carbon material coated ferric sodium pyrophosphate positive electrode material. The dispersing agent is introduced into the sanding slurry, so that the sanding efficiency can be improved, and the dispersity and uniformity of the material can be improved; and meanwhile, a boron-containing dispersing agent and a nitrogen-containing carbon source are used for realizing co-doping on a product carbon layer, so that the electrochemical performance of the material is improved. The invention can effectively improve the discharge capacity and cycle life of the sodium battery.

The invention belongs to the technical field of flame-retardant materials, and particularly relates to modified piperazine pyrophosphate, a composite flame retardant and a preparation method and application of the modified piperazine pyrophosphate and the composite flame retardant. The modified piperazine pyrophosphate provided by the invention is obtained by modifying piperazine pyrophosphate with a modifier; the modifier comprises silicon resin. According to the preparation method, the piperazine pyrophosphate is modified by adopting a specific type of silicon resin as a modifier, and the piperazine pyrophosphate is coated by utilizing a three-dimensional network structure of the silicon resin, so that the hydrophobicity and the flowability of the piperazine pyrophosphate powder can be improved, and the piperazine pyrophosphate powder has good dispersity in a high polymer material; and the paint has good flame retardance, water resistance, acid resistance and alkali resistance.

The present application provides a positive electrode material, a preparation method thereof, a positive electrode sheet, a battery and an electrical apparatus, and relates to the field of batteries. The positive electrode material comprises sodium iron phosphate pyrophosphate and a carbon coating layer covering the surface of same; and the positive electrode material contains an impurity phase sodium ferric phosphate, the mass ratio of the impurity phase sodium ferric phosphate in sodium iron phosphate pyrophosphate being 14% or below. The positive electrode material has a low content of the impurity phase sodium ferric phosphate, such that the initial charging capacity can be effectively improved, and the electrochemical performance of the positive electrode material is effectively improved.

The invention provides a modified ferric sodium phosphate pyrophosphate positive electrode material and a preparation method and application thereof.According to the preparation method, mature sanding, spray drying and calcining processes are adopted, and the ferric sodium phosphate pyrophosphate / carbon positive electrode material with a porous spherical structure and high phase purity is prepared by optimizing the combination of raw materials; and the performance breakthrough of high specific capacity, super-large rate capability and excellent super-large rate cycle performance is realized. The provided preparation method is simple and convenient in technological process, high in controllability and suitable for industrialization, the selected raw materials are wide in source and low in cost, the energy consumption in the technological process is relatively low, and the comprehensive production cost has remarkable advantages; the synthesized ferric sodium pyrophosphate / carbon positive electrode material obtains excellent dynamic performance, electrochemical performance and structural stability at an ultra-large rate at 20 DEG C based on special morphology characteristics and relatively high phase purity.

The invention relates to a flame-retardant polypropylene wire rod and a preparation method and application thereof, the flame-retardant polypropylene wire rod has a core-shell structure, and the shell structure comprises polypropylene, MCA, tetrapod-like zinc oxide, an antioxidant and a lubricant; the core layer structure is prepared from polypropylene, piperazine pyrophosphate, melamine polyphosphate, tetrapod-like zinc oxide, an antioxidant and a lubricant. According to the invention, by controlling the type and content of the flame retardant in the shell layer of the wire rod, the interlayer binding force is not influenced during high-temperature fused deposition printing, a workpiece with relatively high mechanical property can be prepared, and the core layer material of the wire rod has relatively high flame retardant property, so that the prepared workpiece has relatively good flame retardant property. The preparation method of the flame-retardant polypropylene wire rod is simple, electronic and electric appliance structural parts which are complex in structure, difficult to design mold parting surface injection molding, high in mechanical property requirement and high in flame retardant property requirement can be prepared through 3D printing forming, and the flame-retardant polypropylene wire rod has wide application prospects.

The invention provides a novel D-A-D type fluorescent probe material as well as a preparation method and application thereof. The fluorescent probe material has good stability, the preparation process is simple, and the synthesis condition is mild. Moreover, the D-A-D type fluorescent probe material has good solubility and stability, and a complex of the D-A-D type fluorescent probe material and zinc ions can identify pyrophosphate ions with high selectivity and high sensitivity. The interference of phosphate ions, hydrogen phosphate ions, dihydrogen phosphate ions, fluorine ions, chloride ions, nitrate ions, acetate ions, sulfate ions and carbonate ions is avoided; after the zinc ion complex of the D-A-D type fluorescent probe material is combined with PPi, the fluorescence intensity is remarkably enhanced, the D-A-D type fluorescent probe material has a higher signal-to-noise ratio, in-situ imaging detection of a target object in living cells or tissues is realized, the defects of a traditional molecule and ion detection method are overcome, and the D-A-D type fluorescent probe material is suitable for being widely applied to the field of biological imaging. # imgabs0 #

The invention relates to a positive electrode material and a preparation method thereof, a battery and electric equipment. The positive electrode material comprises ferric sodium pyrophosphate, and the content a of sulfur impurities in the positive electrode material is more than or equal to 0 and less than or equal to 100ppm.

The invention belongs to the technical field of sodium ion battery positive electrode materials, and discloses a preparation method and application of a cobalt-containing sodium ion battery positive electrode material. The preparation method comprises the following steps: adding a sodium source, an iron source, a cobalt source, a phosphorus source and a carbon source into isopropanol, uniformly mixing to form slurry, carrying out ball milling on the slurry, drying to obtain a precursor, and calcining in an argon atmosphere to obtain the cobalt-doped carbon-coated ferric sodium pyrophosphate (Na4Fe3-xCox (PO4) 2P2O7) positive electrode material, in which x is greater than or equal to 0 and less than or equal to 0.3. The synthesis method of the ferric sodium pyrophosphate positive electrode material provided by the invention has the advantages of simplicity in operation and low energy consumption, industrial production is facilitated, meanwhile, the synthesized material ensures the stability of a crystal structure in a Na < + > intercalation / deintercalation process, the specific capacity and the rate capability of the material are improved, and the application prospect is wide. The problems of low specific discharge capacity, poor rate capability and the like of the pyrophosphate ferric phosphate sodium material are effectively solved.

The invention discloses an environment-friendly halogen-free efficient flame-retardant composition, a flame retardant, a preparation method and application, and relates to the field of flame retardants, and the environment-friendly halogen-free efficient flame-retardant composition specifically comprises piperazine pyrophosphate, melamine cyanurate, organic phosphonate and polytetrafluoroethylene. The flame-retardant efficiency is improved. By introducing the silane coupling agent, the compatibility of the flame-retardant composition and polyolefin is improved, the processability of the flame retardant and a polyolefin substrate is improved, the precipitation of the flame retardant is reduced, and the flame-retardant composition can continuously and stably exist in a double-85 environment for more than 1000 hours without precipitation. The halogen-free flame retardant prepared by the method can reduce the use cost, solves the problem that most of the halogen-free flame retardants of the scorched piperidine system in the market are easy to separate out, is high in universality, and has a better flame-retardant effect in flame retardance of various types of polyolefins such as polypropylene and polyethylene.

The invention provides a migration-resistant piperazine pyrophosphate flame retardant and a synthesis method thereof, and relates to the field of flame retardants. Comprising the following steps: S1, mixing anhydrous piperazine with water, heating, dropwise adding a phosphoric acid solution into a system, performing microwave heating to 80-90 DEG C, and keeping the temperature for 2-3 hours; adding a coupling agent, uniformly stirring, cooling to room temperature, filtering and drying to obtain modified piperazine diphosphate; s2, mixing the modified piperazine diphosphate prepared in the step S1 with a catalyst, adding the mixture into a kneading machine, heating to 180-220 DEG C, reacting for 2-3 hours, cooling and crushing to obtain a piperazine pyrophosphate crude product; s3, uniformly mixing modified montmorillonite, methyl hydrogen-containing silica oil and a coupling agent, then adding the piperazine pyrophosphate crude product in the step S2 and ammonia water, and performing ultrasonic oscillation, uniform mixing, drying and crushing to obtain the piperazine pyrophosphate flame retardant. The piperazine pyrophosphate is subjected to surface modification, so that the bonding strength of the piperazine pyrophosphate and a resin matrix is improved, and the problem that traditional piperazine pyrophosphate is not resistant to flame retardance and migration is solved.

The invention discloses a carbon-coated ferric sodium pyrophosphate positive electrode material and a preparation method, the carbon-coated ferric sodium pyrophosphate positive electrode material comprises a Na source, a Fe source, aluminum acetate and a P. The carbon-coated ferric sodium pyrophosphate prepared by the invention is used as the positive electrode material of a sodium ion battery, the electric conductivity of the battery is obviously improved, the discharge capacity is obviously improved, and the service life of the battery is prolonged. The rate capability and the low-temperature performance of the battery are greatly improved, the gel enables the material to form a layer of three-dimensional carbon conductive network during sintering, the layer of three-dimensional carbon conductive network improves the conductivity of the material, the in-situ coated carbon layer well inhibits the growth of primary particles, the transmission distance of sodium ions is reduced, and the performance of the battery is improved. The secondary carbon coating is characterized in that a small amount of uniform fluidized bed vapor deposition (CVD) is carried out on the basis of the primary carbon coating, the surface of the material is coated with a layer of nanoscale conductive carbon film again, relatively good temperature treatment is adopted, and the graphitization degree of the coated carbon layer is high, so that the electronic conductivity of the material is improved.