833 results about "Pyrophosphoric acid" 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 provides a doped and coated composite sodium battery positive electrode material as well as a preparation method and application thereof. The doped and coated composite sodium battery positive electrode material comprises an inner core and a coating layer on the surface of the inner core, the chemical general formula of the inner core is NabNixFeyMnzMjO2, x + y + z + j = 1, 0.2 < = x < = 0.6, 0.2 < = y < = 0.5, 0.2 < = z < = 0.5, 0 < j < = 0.2, 0.8 < = b < = 1.2; the coating layer comprises a ferric sodium pyrophosphate material; raw materials for preparing the doped and coated composite sodium battery positive electrode material comprise an inner core, a phosphoric acid ferric sodium pyrophosphate precursor material and a sodium source. The metal elements are doped in the inner core, and the surface is coated with the ferric sodium pyrophosphate material with relatively high stability, so that the inner core can be prevented from being in direct contact with an electrolyte, and the cycle performance of the sodium battery positive electrode material is improved.

The invention relates to a preparation method and application of a manganese ion doped modified ferric sodium pyrophosphate positive electrode material, and belongs to the technical field of sodium ion battery positive electrodes. The preparation method comprises the following steps: adding a sodium source, a phosphorus source and a carbon source into ethanol, uniformly mixing to form a mixed solution, sequentially adding an iron source and a manganese source into the mixed solution, uniformly mixing to form slurry, and drying the slurry to obtain precursor powder; calcining in a protective atmosphere to obtain a manganese-doped carbon-coated ferric pyrophosphate sodium material; the calcining conditions are as follows: heating to the temperature of 300-350 DEG C at the heating rate of 2-3 DEG C / min, carrying out first-stage constant-temperature calcination for 2-3 hours, heating to the temperature of 500-550 DEG C at the heating rate of 5-8 DEG C / min, and carrying out second-stage constant-temperature calcination for 10-12 hours. By doping the manganese ions, the electronic conductivity and the ion diffusivity of the ferric sodium phosphate pyrophosphate composite material are improved, so that the discharge capacity of the ferric sodium phosphate pyrophosphate composite material at high rate is improved, and the battery has relatively high cycle stability.

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 discloses a multiphase ferric sodium pyrophosphate positive electrode material as well as a preparation method and application thereof, and belongs to the technical field of positive electrode materials. The complex-phase phosphoric acid and sodium ferric pyrophosphate positive electrode material has the following chemical formula: xNa4Fe3 (PO4) 2 (P2O7). (1-x) Na3. 12Fe2. 44 (P2O7) 2 / C, C is a carbon coating layer, and the content of the C is 8-10 wt% of the total mass of the composite-phase phosphoric acid and sodium ferric pyrophosphate positive electrode material; xNa4Fe3 (PO4) 2 (P2O7). (1-x) Na3.12Fe2.44 (P2O7) 2 is a core layer, and x is greater than or equal to 0.76 and less than or equal to 0.88. Under the condition that transition metal elements are not added for doping, the electrochemical performance of the complex-phase ferric sodium phosphate pyrophosphate positive electrode material can be obviously improved by regulating and controlling the ratio of positive ions to negative ions of original components of ferric sodium phosphate pyrophosphate, and the complex-phase ferric sodium phosphate pyrophosphate positive electrode material is low in cost, simple to prepare and suitable for large-scale production and application.

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 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 a battery-grade doped modified manganese ferric sodium pyrophosphate positive electrode material as well as a preparation method and application thereof, and belongs to the field of battery materials. An ammonium manganese ferric phosphate precursor is prepared on the basis of an iron process and an ion exchange method, and is prepared into secondarily coated nitrogen-doped carbon-coated sodium manganese ferric phosphate pyrophosphate. According to the method, the content of sulfur impurities in the precursor can be controlled by adopting an ion exchange method, and a secondary sulfur removal process is avoided, so that the content (less than or equal to 100ppm) of the sulfur impurities in the modified manganese ferric ammonium phosphate reaches a battery level, and the cycle performance of the sodium ion battery is improved. The doped metal elements are uniformly distributed in the crystal lattice of the precursor in an atomic scale, so that the internal crystal electronic structure of the manganese ferric sodium phosphate pyrophosphate is effectively regulated and controlled, the structural stability of the manganese ferric sodium phosphate pyrophosphate is improved, meanwhile, the volume expansion effect of sodium ions in the embedding / removing process is relieved, and the electrochemical performance of the positive electrode material is further improved.

The invention discloses an in-situ formed sodium ferric phosphate coated sodium ion positive electrode layered oxide material, a sodium ion battery positive electrode and a sodium ion battery, the method comprises the following steps: preparing a sodium ion positive electrode layered oxide material to be coated, and measuring the residual alkali content of the sodium ion positive electrode layered oxide material; the method comprises the following steps: mixing ferric pyrophosphate with the content equal to that of residual alkali with a raw material for preparing a sodium ion positive electrode layered oxide to form a premix, sintering and slowly cooling, and forming a sodium ferric phosphate coating layer on the sodium ion positive electrode layered oxide material in situ by a residual sodium substance separated out from the surface of the sodium ion positive electrode layered oxide material and ferric pyrophosphate to prepare the sodium ion positive electrode layered oxide material. The sodium iron phosphate in-situ coated sodium ion positive electrode layered oxide material is prepared. According to the sodium ion positive electrode layered oxide material, a dense, uniform and thickness-controllable sodium ferric phosphate coating layer is formed in situ, so that residual alkali on the surface of the material can be effectively reduced, the pH value is reduced, meanwhile, the cell processing performance of the material is improved, the electrolyte corrosion resistance of the surface of the material is effectively enhanced, and the service life of the material is prolonged. The subsequent complicated process flow for reducing the residual alkali is reduced, the capacity of the sodium-ion battery positive electrode material is improved, and the production cost of the sodium-ion battery positive electrode material is reduced.

The invention discloses a sodium ferric pyrophosphate material with a sodium storage dominant crystal face regulated and controlled by cation doping as well as a preparation method and application of the sodium ferric pyrophosphate material. The chemical formula of the prepared sodium ferric pyrophosphate material with the regulated and controlled crystal structure is Na < 4 > Fe < 2.97 > M < 0.03 > (PO4) < 2 > P < 2 > O < 7 >. Wherein M = Sr, or Sr and a second doping element, and the second doping element is selected from one of Cd, Bi, Mo, Ni and Al. The material is prepared by adopting a sol-gel method, an iron source, a chelating agent, a sodium source, a phosphorus source and doping elements are dissolved in deionized water, and stirring is performed until a gel state is formed; and drying and calcining twice to obtain a final product. The sodium ferric pyrophosphate electrode material prepared by the invention has more sodium storage dominant crystal faces, shows good electrochemical performance, has the advantages of simple preparation process, easily available raw materials and low cost, has remarkable industrial application value, and is easy for large-scale production.

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 discloses a NaFePO4 modified sodium ferric phosphate pyrophosphate composite positive electrode material, a preparation method thereof, a positive plate and a battery, the chemical formula of the composite positive electrode material is Na < 4 + x > Fe < 3 + x-y > (PO4) < 2 + x > (P2O7), 0 lt, 0 lt, 0 lt, 0 lt, 0 lt, 0 lt, 0 lt, 0 lt, 0 lt, 0 lt, 0 lt, 0 lt, 0 lt, 0 lt, 0 lt, 0 lt, 0 Xlt; 0 < = y < = 0.1. Wherein x represents the content of NaFePO4, and when 0 lt, x represents the content of NaFePO4; x is more than 0.3 and less than or equal to 0.3, the material exists in the form of a solid solution, no NaFePO4 phase appears, when x is more than 0.3 and less than 1, NaFePO4 appears in the form of a second phase, and the material is a composite phase of NaFePO4 and Na4Fe3 (PO4) 2 (P2O7). The positive electrode material provided by the invention has the characteristics of high theoretical specific capacity, long cycle life and high average working voltage in the aspect of electrochemical performance, is low in cost, environment-friendly, smooth in synthesis path and easy for mass production, and is an ideal sodium ion battery positive electrode material.

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 invention provides a lithium manganese iron phosphate material as well as a preparation method and application thereof. The preparation method comprises the following steps: step S1, ball-milling and mixing a manganese source, an iron source, a phosphorus source and water to obtain first mixed slurry; s2, carrying out ball milling on a lithium source, pyrophosphoric acid, cane sugar and the first mixed slurry to obtain second mixed slurry; s3, carrying out spray drying treatment on the second mixed slurry to obtain a composite precursor with a microsphere structure; and S4, calcining the composite precursor with the microsphere structure at the calcining temperature of 520-700 DEG C in an inert gas atmosphere to obtain the lithium manganese iron phosphate material. Based on the preparation method provided by the invention, the problems of low stacking density, low conductivity, low specific energy and complex process of the lithium manganese iron phosphate material in the prior art are solved.

The invention provides a sodium ferric pyrophosphate positive electrode diaphragm as well as a dry preparation method and application thereof. The dry preparation method comprises the following steps: dividing the conductive agent into a conductive agent A and a conductive agent B; mixing the conductive agent A with the ferric sodium pyrophosphate positive electrode material, and performing first stirring to obtain a first material; mixing a conductive agent B with sodium trifluoromethanesulfonate, and performing second stirring to obtain a second material; mixing the first material with the second material, and performing third stirring to obtain a third material; mixing the third material with a binder, and performing fourth stirring to obtain a fourth material; and the fourth material is subjected to fibrosis treatment and rolling in sequence to obtain the sodium ferric pyrophosphate positive electrode diaphragm. By designing the contents and proportions of the sodium ferric pyrophosphate positive electrode material, the conductive agent, the binder and the sodium trifluoromethanesulfonate and controlling the mixing method, sequence and steps, the sodium ferric pyrophosphate positive electrode diaphragm with high compaction density, high conductivity and excellent ion transmission channels is prepared.

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 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 present invention relates to a modified sodium iron phosphate pyrophosphate composite material and its preparation method and application, belonging to the technical field of sodium ion batteries. The preparation method of the present invention comprises the following steps: S1, adding a soluble doped metal salt solution and a surfactant to a ferrous phosphate solution, and dripping a hydrogen peroxide solution and a hydrofluoric acid solution within 40min-80min under the conditions of 60°C-80°C, reacting at 85°C-98°C for 2h-5h after the dropwise addition, and washing and calcining to obtain a flaky composite precursor; S2, dissolving the flaky composite precursor, a sodium source, a phosphorus source, and a carbon source in water, and obtaining a modified sodium iron phosphate pyrophosphate composite material through sand milling, spray drying, and heat treatment. Element doping and material modification are successfully achieved during the precursor synthesis, thereby achieving optimization of the crystal phase, reduction of the impurity phase, improvement of the energy density, conductivity, and other physical and chemical properties of the NFPP material, and reduction of its water absorption.

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 a PC / PET alloy material as well as a preparation method and application thereof, and belongs to the technical field of high polymer materials. The PC / PET alloy material disclosed by the invention is prepared from the following components in parts by weight: 38 to 57 parts of PC resin, 18 to 32 parts of PET resin, 9 to 16 parts of talcum powder, 1.5 to 8 parts of toughening agent and 0.05 to 0.35 part of ester exchange inhibitor, the pH value of the talcum powder is less than 9, and the D50 particle size is 2-3 [mu] m; the intrinsic viscosity of the PET resin is 0.7 to 0.9 dL / g; the ester exchange inhibitor comprises at least one of sodium pyrophosphate and disodium dihydrogen pyrophosphate. The PC resin and the medium-viscosity PET resin are compounded, and the talcum powder with small pH value and small particle size is selected, so that the degradation of PC can be reduced, the shear heat of a PC / PET system is reduced, and good impact performance and good appearance after heat retention are realized.

The invention belongs to the technical field of sodium ion battery positive electrode materials, and discloses a preparation method of a high-performance ferric pyrophosphate sodium positive electrode material. Performing high-energy ball milling on a sodium source, an iron source, a phosphorus source, an A source and a carbon source to obtain a precursor; and then annealing the precursor in argon to obtain the ferric sodium pyrophosphate positive electrode material doped with high-valence transition metal elements and subjected to iron defect engineering. Through doping of high-valence transition metal elements and regulation and control of iron defect sites, the technical problems that the ferric sodium phosphate pyrophosphate type positive electrode material is poor in conductivity, poor in ionic conductivity and low in compaction density, inactive impurities are easily generated in the preparation process, and the electrochemical performance of the ferric sodium phosphate pyrophosphate type positive electrode material is affected are solved.

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 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.