664 results about "Pyrophosphoric acid" patented technology

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.

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 belongs to the field of battery materials, and discloses a ferric sodium pyrophosphate material as well as a preparation method and application thereof. The preparation method of the ferric sodium pyrophosphate comprises the following steps: step 1, mixing a phosphorus source, an iron source, a sodium source, a biomass carbon source and an alcohol additive, and uniformly stirring to obtain a mixed material A; step 2, carrying out hydrothermal reaction on the mixed material A, and then centrifuging and drying to obtain an intermediate product B; and 3, roasting the intermediate product C in a protective atmosphere to obtain the carbon-coated ferric sodium pyrophosphate. A three-dimensional conductive network is formed after the biomass carbon source and the NFPP are compounded, the interface resistance is reduced, the charge transfer efficiency is improved, and after the biomass carbon source is carbonized, biomass carbon with mechanical supporting and buffering effects can relieve volume expansion of the NFPP in the charge-discharge or reaction process and inhibit material pulverization, so that the cycling stability is improved.

The invention discloses a preparation method of a carbon-coated single-crystal sodium ferric pyrophosphate positive electrode material, which is specifically implemented according to the following steps: step 1, dissolving sodium salt, ferric salt and phosphate in deionized water in proportion, then adding a carbon source into the solution, and uniformly stirring to obtain a mixed solution; step 2, fully drying the mixed solution obtained in the step 1 to obtain precursor powder; and 3, carrying out heat treatment on the precursor powder in a protective atmosphere, and cooling to obtain the carbon-coated single-crystal sodium ferric pyrophosphate positive electrode material. The invention also discloses a coating prepared by the method, a single-crystal structure is combined with uniform carbon coating, grain boundary defects are eliminated, conductivity is improved, high specific capacity and long cycle life are realized, single-crystal growth and carbon layer in-situ coating are synchronously realized by a synthesis process, and structural integrity and efficient conductive network construction can be ensured.

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 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 present invention discloses a method for preparing a composite sodium ferric pyrophosphate cathode material, which relates to the technical field of sodium batteries and includes the following steps: Step S1, preparing a precursor; Step S2, combining it with a carbon source; and Step S3, sintering it. The composite sodium ferric pyrophosphate cathode material disclosed in the present invention has excellent electrochemical performance, good electrical conductivity, strong cycle performance and rate performance, and high initial charge and discharge efficiency.

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 relates to the technical field of biology, in particular to application of brassinolide in increasing the yield of lettuce latex. According to the invention, brassinolide is adopted as an active component and acts on lettuce plants, so that the yield of lettuce latex can be remarkably increased, and meanwhile, the contents of sucrose and isopentenyl pyrophosphate in lettuce are further remarkably increased. Compared with indoleacetic acid, the brassinolide provided by the invention is more suitable for improving the gum production performance of the plant lettuce, and the brassinolide and the indoleacetic acid are high in adaptability, so that a more excellent technical effect is obtained. In the use process, the use method of brassinolide is simple, the use amount is small, the function of remarkably improving the yield of lettuce latex, sucrose and isopentenyl pyrophosphate can be achieved by adopting brassinolide with low concentration, the cost is low, the effect is good, no new toxic or side effect is caused to the environment, and the brassinolide is suitable for application and popularization.

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 invention relates to the field of electrolytic copper foil processing and application, and discloses a chromium-free environment-friendly passivation solution and an electrolytic copper foil preparation method, and the passivation solution is composed of 80-120 mg / L of silver phosphate, 5-20 mg / L of o-tert-butylphenol, 60-100 mg / L of potassium pyrophosphate and 10-40 mg / L of sulfuric acid. The o-tert-butylphenol can be adsorbed to the crystal boundary of a silver layer to form antioxidant free radicals, and the antioxidant free radicals are preferentially combined with oxygen molecules to form a stable compound, so that the oxidation resistance is improved; and meanwhile, the o-tert-butylphenol can be combined with a silica group of the silane coupling agent, so that the adhesive force of the silane coupling agent on the metal surface is increased, and the stripping resistance of the copper foil is 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 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 present application discloses a method for preparing a composite sodium ferric pyrophosphate material, comprising the following steps: S1, uniformly dispersing a sodium source, an iron source, a phosphorus source, a carbon source, and a surfactant in a solvent according to a stoichiometric ratio to form a dispersion; S2, sand-milling the dispersion at a temperature T1 and discharging the slurry, controlling the discharge temperature of the slurry to T2; wherein temperatures T1 and T2 satisfy the following conditions: 20°C ≤ T1 ≤ 40°C, 20°C ≤ T2 ≤ 40°C, and T1 > T2; S3, spray-drying the slurry obtained in step S2 and sintering it to obtain the composite sodium ferric pyrophosphate material. This preparation method can greatly improve the problem of slurry agglomeration, thereby obtaining a high-quality composite sodium ferric pyrophosphate material with excellent electrochemical performance.

The invention discloses a nickel-tin alloy-oxide composite material Ni3Sn2-NiSnOx, a preparation method thereof and application of the nickel-tin alloy-oxide composite material Ni3Sn2-NiSnOx in electrocatalytic ammonia synthesis reaction, and belongs to the technical field of electrochemical catalysis. The preparation method comprises the following steps: adding SnCl2. 2H2O and NiCl into deionized water as raw materials, adding glycine, potassium pyrophosphate and urea as electro-deposition auxiliary agents, and stirring for 10 minutes to obtain electro-deposition liquid; and carrying out electro-deposition on a conductive substrate serving as a cathode, so that Ni and Sn are co-deposited to form a nickel-tin alloy, and part of the nickel-tin alloy reacts with oxygen in the deposition process or after deposition to form a nickel-tin oxide phase, so that the Ni3Sn2-NiSnOx composite catalytic material is obtained. By regulating and controlling the concentration of tin ions in the electroplating solution and the electrodeposition time, the component proportion of nickel and tin in the product and the morphology structure of the material can be regulated. The composite material provided by the invention has excellent electrocatalytic nitrogen reduction synthesis ammonia activity and selectivity, and solves the problems that the service life of a catalyst is shortened and the catalytic activity and stability are reduced due to irreversible reconstruction of an alloy compound under high potential.

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.

A positive electrode lead paste for a high-capacity and long-service-life storage battery and a preparation method therefor. The formula of the positive electrode lead paste comprises lead powder, dilute sulfuric acid, water and additives. In parts by mass, the additives added to every 1000 parts of the lead powder comprise: 1-3 parts of sodium perborate; 0.5-2 parts of 4BS; 1-3 parts of antimony trioxide; 1-3 parts of tin pyrophosphate; 2-4 parts of a polyolefin; 2-4 parts of a conductive carbon material; and 1-1.5 parts of a polyester staple fiber. By adding tin pyrophosphate and the polyolefin in the positive electrode lead paste, the capacity of a lead storage battery can be effectively increased and the service life thereof can be prolonged; and tin pyrophosphate and the polyolefin can work synergistically, and the addition of the two together achieves a better effect.

The invention provides a positive active material and a preparation method thereof, a positive pole piece, a sodium battery and an energy storage device. The positive electrode active material provided by the embodiment of the invention comprises ferric sodium phosphate pyrophosphate particles and a carbon coating layer, wherein the surface of the ferric sodium phosphate pyrophosphate particles is coated with the carbon coating layer; in the positive electrode active material, the mass fraction w of the carbon coating layer is greater than or equal to 2.6% and less than or equal to 3.2%.

The invention relates to a preparation method of a porous sodium-ion battery ferric phosphate sodium pyrophosphate positive electrode material, and belongs to the technical field of sodium-ion battery positive electrode materials. The method comprises the steps of precursor slurry preparation, sanding, spray drying, low-temperature heat treatment, surface activation, double-stage etching, high-temperature calcination and the like. Wherein an isopropanol-hydrofluoric acid system is adopted to perform first-stage etching on the precursor so as to open the carbon coating layer and improve the permeability of subsequent etching liquid; and then, carrying out second-stage deep etching under a heating condition by adopting a hydrofluoric acid-sodium citrate system, so as to effectively remove the silicon dioxide template and form a through type porous structure. The obtained positive electrode material has a good pore structure and a conductive network, and electrolyte infiltration and construction of a sodium ion diffusion channel are facilitated, so that the rate capability and the cycle stability of the positive electrode material are improved. The preparation method disclosed by the invention is simple and convenient in process and suitable for large-scale preparation of the high-performance sodium-ion battery positive electrode material.

The invention relates to the technical field of flame-retardant high polymer materials, in particular to a high-temperature-resistant and high-humidity-resistant flame-retardant polypropylene composite material and a preparation method thereof. The invention provides a high-temperature-resistant and high-humidity-resistant flame-retardant polypropylene composite material. The high-temperature-resistant and high-humidity-resistant flame-retardant polypropylene composite material consists of polypropylene, a mixed silane modified intumescent flame retardant, a flame-retardant aid NOR 116 and a compatilizer According to the invention, bis [3-(trimethoxysilyl) propyl] amine / triacetoxyvinyl silane is mixed to modify an intumescent flame retardant, which is composed of piperazine pyrophosphate as a main flame retardant and melamine polyphosphate, aluminum hypophosphite or aluminum diethylphosphinate as a secondary flame retardant; a plurality of active silicon hydroxyl sites after silane hydrolysis are mixed, and single flame retardants are connected together to form a macromolecular intumescent flame retardant, so that the modified intumescent flame retardant is still difficult to migrate or separate out from a polypropylene matrix even under high-temperature and high-humidity conditions, and the weather resistance of flame-retardant polypropylene is greatly improved.

The invention discloses a rapidly synthesized ferric sodium pyrophosphate electrode material, a preparation method thereof and a positive electrode. Relates to the technical field of batteries. The preparation method comprises the following steps: S1, mixing a sodium source, an iron source, a phosphorus source and a carbon source, adding a preset volume of deionized water, and stirring until the raw materials are completely dissolved to obtain a light yellow transparent solution; s2, adding a preset amount of modified carbon nanotubes into the light yellow transparent solution, and dispersing in an ultrasonic environment to obtain a stable suspension; s3, starting a spray dryer, and collecting yellow green spherical precursor powder from a discharge port; s4, placing the yellow green spherical precursor powder obtained by spray drying in a magnetic boat, and carrying out heat preservation at 300 DEG C in a pure argon environment at a heating rate of 2 DEG C / min for 5 h to obtain black powder; and S5, transferring the black powder into Joule thermal equipment, and reacting for a preset time under a preset condition to obtain a final black powdery product. Through innovative process design and material modification, the core problems of long period, poor conductivity, low tap density and the like in the traditional preparation technology are solved.

The invention discloses a method for preparing ferromanganese phosphate MnxFe (1-X) PO4, which comprises the following steps of: mixing a manganese pyrophosphate complex solution and an iron phosphate complex solution, and decomplexing to form ferromanganese phosphate precipitate; wherein the manganese pyrophosphate complex is formed by manganese III ions and pyrophosphoric acid; the iron phosphate complex is formed from phosphate ions and iron III ions. According to the preparation method of the ferromanganese phosphate, the ferromanganese phosphate product can be stably obtained, and the proportion of Mn to Fe in the ferromanganese phosphate can be adjusted according to needs.

The invention provides a sodium ion positive electrode material and a preparation method and application, and belongs to the field of sodium ion batteries, the sodium ion positive electrode material comprises an inner core and a coating layer coating the inner core, the inner core is ferric sodium phosphate pyrophosphate, the coating layer is a carbon coating layer, the carbon coating layer comprises an organic carbon source, an inorganic carbon source and MXene, and the organic carbon source and the inorganic carbon source are mutually connected. And the thickness of the carbon coating layer is 0.2 [mu] m-0. 4 [mu] m. In the carbon coating layer, inorganic and organic carbon are compounded and MXene is doped, and meanwhile, the thickness of the carbon coating layer is controlled, so that the compaction density, the conductivity and the structural stability of the sodium ion positive electrode material are favorably improved, and the rate capability and the cycling stability of the sodium ion positive electrode material are further improved.

The invention discloses a ceramic membrane cleaning agent which comprises an agent A, an agent B, an agent C and water, wherein the agent A comprises sodium dodecyl sulfate and a polyoxyethylene ether nonionic surfactant; the agent B comprises potassium pyrophosphate and ethylenediamine tetraacetic acid tetrasodium salt; the agent C comprises sodium hypochlorite. The invention further discloses a preparation method of the ceramic membrane cleaning agent. The problems that an existing ceramic membrane cleaning agent is common in cleaning effect, and the service life of a ceramic membrane is affected due to incomplete cleaning are solved. The agent A is selected from sodium dodecyl sulfate and a polyoxyethylene ether nonionic surfactant, and the sodium dodecyl sulfate and the polyoxyethylene ether nonionic surfactant both have an emulsifying effect and good compounding property and can enhance the emulsifying effect through a synergistic effect; in the agent B, the potassium pyrophosphate and the tetrasodium ethylenediamine tetraacetate have a synergistic effect, and the potassium pyrophosphate and the tetrasodium ethylenediamine tetraacetate are matched, so that the cleaning effect can be improved, and the decontamination capability can be enhanced. The agent C is matched with the agent A and the agent B, so that the overall stability of the cleaning agent is ensured. Therefore, the ceramic membrane has antibacterial, efficient decontamination and efficient emulsification performance at the same time.

The invention relates to a sodium ferric fluorophosphate pyrophosphate positive electrode material as well as a preparation method and application thereof, belongs to the technical field of sodium ion batteries, and solves the problems of high fluorine content, high toxicity and poor cycle performance of sodium ferric fluorophosphate pyrophosphate in the prior art. The molecular formula of the sodium ferric fluorophosphate pyrophosphate positive electrode material is Na (3-2y + x) Fe2-y (PO4) (P2O7) (1-y) F (x) (at) C, the value range of y is more than or equal to 0 and less than 1.0, and the value range of x is more than 0 and less than or equal to 1.0. The sodium ferric fluorophosphate pyrophosphate positive electrode material disclosed by the invention has relatively high compaction density, relatively high gram volume and good cycle performance.

The invention relates to the technical field of sodium-ion battery materials, in particular to a preparation method of a sodium-ion battery precursor and a sodium-ion battery. The preparation method comprises the following steps: preparing a manganese-iron mixed salt solution, and preparing a magnesium sulfate solution; the preparation method comprises the following steps: adding a manganese-iron mixed salt solution and a magnesium sulfate solution into a reaction kettle, then adding a sodium source, adjusting the pH value for reaction, washing the material after the reaction is finished, diluting and dissolving the washed material, then heating, then adding a phosphorus source to adjust the pH value for reaction, and aging after the reaction is finished to obtain doped manganese-iron-sodium pyrophosphate precursor slurry; and then washing and drying the slurry to obtain the doped sodium ferromanganese pyrophosphate precursor material. The precursor material, a sodium source, a phosphorus source and a carbon source are mixed, sanded and sintered to obtain the positive electrode material of the sodium ion battery, and then the positive electrode material is used for preparing the sodium ion battery. A sodium ferromanganese phosphate precursor is prepared by adopting a coprecipitation method, ferromanganese is uniformly distributed, and a product with a special structure is prepared by adopting a special process route.

The invention provides a sodium-rich ferric sodium pyrophosphate positive electrode precursor and a preparation method and application thereof.The preparation method comprises the following steps that a ferrite solution, a phosphoric acid source solution, a pyrophosphoric acid source solution, an alkaline solution and a sodium persulfate solution are injected into a base solution in a parallel flow mode for a co-precipitation reaction, the sodium-rich ferric sodium pyrophosphate positive electrode precursor is obtained; wherein the base solution is pure water. The method disclosed by the invention is simple to operate, the sodium-rich ferric sodium pyrophosphate positive electrode precursor with high sodium content, uniform element distribution and uniform phase can be prepared, the sodium-rich ferric sodium pyrophosphate positive electrode precursor is low in gas production rate in the subsequent sintering process, and the sodium-rich ferric sodium pyrophosphate positive electrode material with high compaction density can be prepared.

The invention relates to the technical field of sodium ion batteries, in particular to a modified ferric sodium pyrophosphate positive electrode material as well as a preparation method and application thereof. The modified ferric sodium pyrophosphate positive electrode material is Na < 4-x > A < x > Fe < 3-y > M < y > (PO4) < 2-z > E < z > (P2O7) w, wherein A is selected from any one or more of alkali metal ions or alkaline earth metal ions of which the ion radius is greater than Na < + >; m is selected from any one or more of transition metal ions; e is selected from any one or more of SiO4 < 4->, SO4 < 2->, BO3 < 3-> or F <->; 0.1 < = x < = 0.3, 0.1 < = y < = 0.3, 0.04 < = z < = 0.1, and the value of w enables positive and negative charges to be balanced. The stability of a crystal structure is optimized through multi-site multi-element doping, the ion / electron conduction efficiency is improved, and the oxidation reduction behavior is regulated and controlled, so that the cycle life, the rate capability and the energy density of the sodium ferric pyrophosphate positive electrode material are comprehensively improved.

The invention discloses a high-entropy ferric pyrophosphate sodium ion battery positive electrode material and a preparation method thereof, and belongs to the field of battery positive electrode materials. The chemical formula of the positive electrode material is Na4Fe3-aMa (PO4) 2P2O7 (0.05 < = a < = 0.5), M is a metal element and comprises at least five of cobalt, magnesium, zirconium, zinc, aluminum, molybdenum, copper, manganese, nickel, calcium and chromium, the high-entropy ferric sodium phosphate pyrophosphate battery positive electrode material is spherical, and the surface of the high-entropy ferric sodium phosphate pyrophosphate battery positive electrode material is coated with an amorphous carbon layer. The preparation method adopts a sol-gel method and comprises the following steps: mixing an iron source, a doped metal source, sodium pyrophosphate, ammonium dihydrogen phosphate and citric acid monohydrate according to a stoichiometric ratio, stirring, gelatinizing and drying to obtain xerogel, and calcining through a two-stage hydrogen-argon mixed gas to obtain the iron-doped metal-doped sodium pyrophosphate / citric acid composite material. The crystal structure is optimized by means of the high-entropy synergistic effect, the electron conductivity and the Na < + > diffusion rate are improved, and the industrial adaptability of the spherical morphology and the structural stability of carbon coating are combined.