690 results about "Iron sulfate" patented technology

The invention relates to a sodium ion battery, and belongs to sodium ion batteries. The battery cell of the sodium-ion battery comprises a positive plate, a negative plate and an electrolyte, the active material of the positive plate is carbon-coated aluminum-doped sodium ferric sulfate; the chemical formula of the aluminum-doped sodium ferric sulfate is Na < 2 + 2y > Fe < 2-x-y > Al < x > (SO4) 3, x is more than or equal to 0.01 and less than or equal to 0.05, and y is more than or equal to 0.1 and less than or equal to The particle size of the carbon-coated aluminum-doped sodium ferric sulfate ranges from 50 nm to 100 nm; the weight ratio of a carbon coating layer in the carbon-coated aluminum-doped sodium ferric sulfate is 1%-5%; the active material of the negative plate is carbon-coated sodium titanate; the specific surface area of the carbon-coated sodium titanate is 20 m < 2 > / g to 25 m < 2 > / g; the weight ratio of a carbon coating layer in the carbon-coated sodium titanate is 0.5%-3%. Volume expansion is jointly inhibited through structural stability of positive and negative electrode materials, and the cycle life is prolonged.

The invention relates to the technical field of water treatment agent preparation and environmental governance material processing, in particular to polymeric ferric sulfate and a preparation method thereof.The preparation method comprises the steps that steam condensation recycled water of a thermal power plant of an aluminum factory is mixed with ferrous sulfate and concentrated sulfuric acid to form a reaction solution, oxygen is introduced for an oxidative polymerization reaction, and a liquid intermediate is generated; gradient cooling is carried out on the liquid intermediate to control the molar ratio of ferric ions to hydroxyl, and a porous solid precursor is formed through concentration and closed aging; crushing the precursor, performing graded drying by adopting a rotary kiln and flash drying, and synchronously spraying a hydrophobic modifier to reduce the surface hydroxyl activity; the powdery product is secondarily dried in a nitrogen inert environment, and moisture absorption and agglomeration are inhibited. The invention solves the problems of mixed crystal forms, delayed release of effective components and secondary pollution in the traditional process. The obtained product is uniform in crystal form, concentrated in particle size distribution, remarkably improved in dissolution rate and storage stability, and suitable for black and odorous water body treatment and industrial sewage treatment.

The invention provides an impurity removal and recovery method of electrodeposited nickel anolyte, which comprises the following steps: (1) mixing the electrodeposited nickel anolyte with liquid caustic soda, carrying out solid-liquid separation to obtain nickel hydroxide and filtrate, and evaporating the filtrate to obtain sodium sulfate; mixing the electrodeposited nickel anolyte with a nickel source to obtain a mixed solution; (2) mixing the mixed solution with barium salt, and carrying out lead removal treatment; (3) adjusting the pH value of a material obtained after lead removal treatment by using nickel hydroxide to obtain a solution to be subjected to arsenic removal, and mixing the solution to be subjected to arsenic removal with polyferric sulfate for arsenic removal treatment; and (4) a material obtained after arsenic removal treatment is mixed with an oxidizing agent, a solution to be subjected to iron removal is obtained, solid-liquid separation treatment is conducted on the solution to be subjected to iron removal, catholyte with lead, arsenic and iron removed and iron-containing slag are obtained, sodium sulfate is supplemented into the catholyte with lead, arsenic and iron removed, and the catholyte is reused in the nickel electrodeposition process. According to the method, lead, arsenic and iron in the electrodeposited nickel anolyte can be efficiently and rapidly removed and recycled.

The invention belongs to the technical field of sodium ion batteries, and particularly relates to a sodium ferric sulfate composite positive electrode material and a preparation method and application thereof. The preparation method of the sodium ferric sulfate composite positive electrode material provided by the invention comprises the following steps: (1) preparing a carbon-coated sodium ferric sulfate positive electrode material, mixing the sodium ferric sulfate positive electrode material with a citric acid solution, and performing ultrasonic treatment to obtain a modified sodium ferric sulfate positive electrode material; (2) stirring and mixing the modified sodium ferric sulfate positive electrode material and a composite conductive agent, shearing and dispersing, and carrying out ultrasonic oscillation, wherein the rotating speed of stirring and mixing is less than or equal to 2000rpm; the rotating speed of the shearing dispersion is greater than or equal to 5000rpm. The sodium ferric sulfate composite positive electrode material provided by the invention has relatively low shear viscosity and relatively high thixotropic index under the condition that the solid content is greater than or equal to 65%.

The invention provides a carbon-coated europium-doped sodium ferric sulfate positive electrode material and a preparation method thereof, a sodium ion battery and electric equipment, and relates to the field of sodium ion batteries. The carbon-coated europium-doped sodium ferric sulfate positive electrode material comprises an inner core and a carbon coating layer coating the inner core, wherein the inner core comprises europium-doped sodium ferric sulfate; the chemical formula of the carbon-coated europium-doped sodium ferric sulfate positive electrode material is Na < 2.4 > Fe < 1.8-3x > Eux (SO4) 3 / C, and x is more than 0 and less than or equal to 0.1. The sodium ferric sulfate is subjected to carbon coating and europium doping, so that the specific discharge capacity and the rate capability of the positive electrode material can be effectively improved.

The invention provides a purification and impurity removal method of a crude nickel-cobalt-manganese sulfate solution. The purification and impurity removal method comprises the following steps: (1) adding sodium thiosulfate into the crude nickel-cobalt-manganese sulfate solution to remove copper; (2) phosphate is adopted, the pH value is regulated, and titanium, iron, aluminum and the like are removed; (3) ferric sulfate is added, the pH value is regulated, and phosphorus and silicon are removed; (4) adding a bismuth agent and regulating the pH value to remove chlorine; (5) adding a fluorine agent to remove calcium and magnesium; and (6) adding a tillite mineral adsorbent to remove fluorine. According to the method, iron, aluminum, copper, fluorine, phosphorus, titanium, calcium, magnesium, chlorine, silicon and other elements can be efficiently removed from the rough nickel-cobalt-manganese sulfate solution, the loss of main metal is low, the prepared high-purity nickel-cobalt-manganese sulfate solution can directly meet the requirement of a precursor solution of a battery preparation level, the process is simple, the operation difficulty is low, industrial large-scale production is easy to achieve, and the method is suitable for industrial production. And the defects of the current preparation method of the high-purity nickel-cobalt-manganese sulfate solution are overcome.

The invention relates to the technical field of sodium ion battery positive electrode materials, and discloses a preparation method and application of a carbon-coated sodium ferric sulfate positive electrode material, and the preparation method comprises the following steps: (1) adding an iron source into an aqueous solution containing an organic acid, and stirring, the organic acid being ascorbic acid and / or citric acid; adding a sodium source or the sodium source and a sulfuric acid source, and stirring; (2) finally adding a carbon source, dropwise adding absolute ethyl alcohol while stirring, vacuumizing after dropwise adding, and continuously stirring for 2-4 hours to obtain a mixed solution; and (3) carrying out closed spray drying on the mixed solution, and calcining in an inert atmosphere to obtain the carbon-coated sodium ferric sulfate positive electrode material. According to the preparation method, coating of the carbon material is achieved in a closed spray drying mode, the conductivity of sodium ferric sulfate is greatly improved, in the whole preparation process, contact with oxygen is avoided, organic acid with an anti-oxidation effect is avoided, ferrous iron is prevented from being oxidized, and then the electrochemical performance can be further improved.

The invention relates to the technical field of sodium-ion batteries, in particular to a sodium-ion battery positive electrode material and a preparation method thereof.The sodium-ion battery positive electrode material comprises a sodium ferric sulfate precursor and a carbon coating layer coating the surface of the sodium ferric sulfate precursor; the sodium ferric sulfate precursor comprises a sodium source, an iron source, an antioxidant and halogenated carboxylic acid; and the carbon coating layer is formed by coating and sintering phosphate. Aiming at the problem that a carbon-coated positive electrode material in the prior art is easy to form defect points, the carbonization temperature in the sintering process is reduced by adding halogenated carboxylic acid into a precursor, so that the carbonization effect is improved, the probability of forming the defect points is reduced, and halogen ions are introduced into a carbon-coated layer in the sintering process to improve the conductivity; meanwhile, surface coating is carried out through phosphate, so that reaction of the positive electrode and electrolyte under a high-voltage condition can be effectively inhibited, gradual deterioration of the material structure due to moisture absorption in the circulation process is avoided, and the circulation stability of the material is improved.

The invention relates to the technical field of water treatment, and provides an efficient chitosan-polyferric sulfate composite coagulant and a preparation method thereof. In order to solve the problems that a traditional inorganic coagulant is prone to secondary pollution, an organic coagulant is high in cost and complex in process control and the like, the invention provides a solution that natural chitosan serves as a raw material, the charge characteristic of the natural chitosan is enhanced through quaternary ammonium salt modification, and then the natural chitosan is compounded with the inorganic coagulant according to a specific proportion. The preparation method comprises the following steps: dissolving chitosan in a 2% acetic acid solution, adjusting the pH value to weak acidity, introducing quaternary ammonium salt, carrying out catalysis by an initiator at a constant temperature of 70 DEG C to complete a reaction, and carrying out centrifugal washing and vacuum drying to obtain modified chitosan; and then compounding with an inorganic coagulant according to a mass ratio of 1: (3-5) to form a composite system with charge neutralization and adsorption bridging functions. According to the invention, by accurately controlling the ratio of the components and process parameters, the preparation process is simple and controllable, and the obtained composite coagulant has the characteristics of high treatment efficiency, environmental friendliness and moderate cost.

The invention belongs to the technical field of sodium-ion battery materials, and mainly relates to a low-cost high-specific-energy mixed positive electrode material and a preparation method and application thereof. The mixed positive electrode material is prepared from 90 to 100 parts of P2 type layered oxide and 1 to 10 parts of polyanionic sodium ferric sulfate; the chemical formula of the P2 type layered oxide is Na2 / 3Ni2 / 3-xMn2 / 3-yTiMgZnO2, x is more than or equal to 0, and y is less than or equal to 1 / 3; the chemical formula of the polyanionic sodium ferric sulfate is Na < 2 + 2 > z Fe < 2-z > (SO4) 2, wherein z is more than or equal to 0 and less than or equal to 0.3. According to the mixed positive electrode material, through the synergistic effect of the crystal structures, the two materials are embedded or wrapped, so that the porosity is reduced, the compaction density is increased, and the specific discharge capacity is improved.

The invention belongs to the technical field of metallurgy, and particularly relates to a method for recovering valuable metals from smelting electric dust. The method comprises the following steps: S1, adding sulfuric acid, ferric sulfate and hydrogen peroxide into the smelting electric dust, and after reaction, carrying out solid-liquid separation to obtain an acidic leaching solution and acidic leaching residues; s2, sodium hydroxide is added into the acid leaching residues obtained in the step S1, the pH value of the acid leaching residues is adjusted to 13.5 or above, and alkaline leaching liquid and alkaline leaching residues are obtained after reaction; s3, sulfuric acid is added into the alkaline leachate obtained in the step S2, the pH value of the alkaline leachate is adjusted to 10.0-12.5, and neutralization liquid and lead slag are obtained after reaction; and S4, roasting the lead slag obtained in the step S3 to obtain lead oxide. According to the method, ferric sulfate is added in the acid leaching process of the smelting electric dust, leaching of arsenic can be effectively inhibited, and efficient separation and recovery of valuable metal can be effectively achieved by subsequently changing the acid-base environment of the reaction.

The present invention belongs to the technical field of resource recovery, and specifically relates to a method for removing impurities from a lithium-ion battery leachate. The method for removing impurities from a lithium-ion battery leachate provided by the present invention produces polyferric sulfate for phosphorus removal while removing iron, thereby achieving iron and phosphorus removal without increasing reagent consumption and steps. The present invention can use an excess of fluorine-containing reagents to ensure that calcium and magnesium are completely removed while removing calcium and magnesium, and then use a defluorination material to remove excess fluorine; the defluorination materials used in the present invention can be reused in subsequent processes, reducing the consumption of defluorination materials. The method for removing impurities provided by the present invention realizes material recycling while improving the purity of the lithium-ion battery leachate, and does not generate excessive waste liquid, thereby improving environmental protection.

The invention discloses a biomass-inorganic-organic ternary composite flocculant and a preparation method and application thereof, and belongs to the field of coking wastewater treatment.The preparation method comprises the steps that chitosan serves as a substrate material, glutaraldehyde serves as a cross-linking agent, and polyferric sulfate (PFS) and chitosan are subjected to chemical cross-linking to generate an intermediate product PFS and chitosan composite particles; then potassium persulfate is used as an initiator, graft copolymerization of acrylamide and methacryloyloxyethyl trimethyl ammonium chloride is initiated through hydroxyl on the surface of PFS-chitosan, a cationic branched chain is introduced, and a final product is obtained. Through multi-component cooperation and structural design, the defects that a traditional flocculating agent is not thorough in demulsification, large in sludge amount, unstable in floc combination and the like in coking wastewater treatment are overcome, and the flocculating agent is particularly suitable for treating oil pollutants in coking wastewater.

The invention belongs to the technical field of sodium ion batteries, and particularly relates to a modified sodium ferric sulfate positive electrode material as well as a preparation method and application thereof. The chemical structural formula of the modified sodium ferric sulfate positive electrode material is Na < 2 + 2x > (Fe < 1-a-b > MaMb < 2-x > (SO4) z (PO4) < 3-z, a is more than 0 and less than 1, b is more than 0 and less than 3, z is more than 0 and less than 3, Ma and Mb are transition metal elements, and Ma is Ni; and Mb is Zn. The transition metal element is introduced and the doping proportion is controlled, so that fine regulation and control on the material performance can be realized, the conductivity and the ion diffusion rate of the positive electrode material are improved, and the structural stability and the air stability of the material are enhanced; the problems of slow Na < + > diffusion kinetics, poor crystallinity and poor material air stability of the sodium ferric sulfate positive electrode material are solved, and a new possibility is provided for the development of a sodium ion battery technology.

The invention discloses a positive electrode material formed by compounding polyanionic sodium ferric sulfate and a layered transition metal oxide, and a preparation method and application thereof, and the preparation method comprises the following steps: preparing a sodium ferric sulfate positive electrode material, preparing a layered transition metal oxide positive electrode material, and mechanically mixing the sodium ferric sulfate and the layered transition metal oxide material, the composite material is obtained. The production process of the two materials is easy for large-scale production, has high similarity with the existing battery industrial equipment, is simple in method for compounding the two materials, and has large-scale industrial application value. The composite material has the stability of a polyanionic material and the high energy density of a layered oxide material, and has more excellent comprehensive electrochemical performance.

The invention belongs to the technical field of clay type lithium ore dressing and smelting, and particularly relates to a grinding and leaching integrated gradient lithium extraction method for clay type lithium ore (containing lithium in an adsorption state and an independent mineral state at the same time), which comprises the steps of ore grinding, pretreatment roasting, grinding and leaching integration and agitation leaching. Wherein in the grinding and leaching integrated process, sulfuric acid or ferric sulfate is added during ore grinding, and a lithium leaching solution a with low impurity content is obtained after solid-liquid separation; in the agitation leaching process, sulfuric acid is used for leaching the leaching residues a, lithium leaching liquid b with the high impurity content is obtained, and the method is high in lithium extraction rate and recovery rate, classification and impurity removal of the leaching liquid are easy, and generated waste water is convenient to treat and utilize. According to the method, the raw ore treatment capacity of the roasting procedure is effectively improved, the energy consumption of lithium carbonate production is reduced, meanwhile, sulfuric acid enhanced leaching of all roasted materials of clay type lithium ore in a complex occurrence state is avoided, the use amount of sulfuric acid and the impurity removal cost of the leachate are effectively reduced, and cost reduction and efficiency improvement are obvious.

The invention belongs to the field of secondary resource recycling, and discloses a method for preferentially extracting lithium from a waste lithium iron phosphate battery positive electrode material through salt leaching, the waste lithium iron phosphate battery positive electrode material is leached by adopting a soluble chloride and metal sulfate mixed solution, and a lithium-containing leaching solution and ferrophosphorus slag are obtained, the soluble chloride solution is selected from at least one of a potassium chloride solution, an ammonium chloride solution or a sodium chloride solution, and the metal sulfate comprises at least one of ferric sulfate, copper sulfate and high-valence manganese sulfate. According to the method, the valuable metal is recycled from the waste lithium iron phosphate battery powder by adopting a novel salt leaching process, the use of a large amount of acid and alkali reagents in a conventional wet process is avoided, the whole recycling process is green, environment-friendly and low in cost, and the lithium-extracted liquid is recycled after being blended, so that the input cost of a production reagent is reduced, and the efficient utilization of the reagent is realized; no waste water is generated, and cleaning and environment-friendly effects are achieved.

The invention provides a sodium vanadium fluorophosphate in-situ coated sodium ferric sulfate / carbon composite material and a preparation method thereof.The preparation method comprises the steps that raw materials including a reducing agent, an iron source, a sodium source and a carbon source are added into absolute ethyl alcohol to be stirred, sanded and mixed, and after obtained slurry is subjected to spray drying, the slurry is sintered and cooled in the argon atmosphere to obtain the sodium ferric sulfate / carbon composite material; mixing the sodium ferric sulfate / carbon composite material dispersion liquid with the sodium vanadium fluorophosphate precursor solution, performing hydrothermal reaction, centrifuging, washing and drying to obtain the sodium vanadium fluorophosphate in-situ coated sodium ferric sulfate / carbon composite material. According to the preparation method, a sodium vanadium fluorophosphate coating layer is generated on the surface of sodium ferric sulfate in situ by combining a low-temperature solid-phase method with a hydrothermal method, so that the sodium vanadium fluorophosphate in-situ coated sodium ferric sulfate / carbon composite material is obtained, the electronic conductivity of the composite material is greatly improved, and the sodium ion diffusion rate is promoted by coating of sodium vanadium fluorophosphate; fe2 + is prevented from being oxidized into Fe3 + due to direct contact between the sodium ferric sulfate and air, so that the air stability of the sodium ferric sulfate is improved.

The invention discloses an oxide-coated ion-doped sodium ferric sulfate positive electrode material as well as a preparation method and application thereof. The positive electrode material is formed by compounding a sodium ferric sulfate bulk phase material doped with various valence metal cations and anions and coated with carbon similar to a positive temperature coefficient thermosensitive metal oxide. Wherein the metal cations with various valence states are doped on Na or Na / Fe ion sites of the sodium ferric sulfate, the doped anions occupy part of three-dimensional S-O tetrahedron positions, the inorganic carbon in the carbon compound is uniformly distributed in the sodium ferric sulfate bulk phase material, and the organic carbon is uniformly distributed outside the sodium ferric sulfate bulk phase material. The positive electrode plate assembled battery prepared from the positive electrode material has the advantages of high reversible charge-discharge capacity, excellent cycle performance and rate capability and high electron and ion migration rate in a low-temperature environment. The method is low in raw material cost, simple in synthesis method, short in production period and suitable for large-scale continuous production.

The invention provides a method and system for recovering phosphate radicals, fluorine ions and sulfate radicals from phosphogypsum washing water step by step, and belongs to the technical field of industrial wastewater resourceful treatment. The method comprises the following steps: (1) adjusting the pH value of the wastewater to 3.0 + / -0.5, adding ferric sulfate according to the molar ratio of Fe to PO4 < 3-> of (1.0-1.5): 1, and selectively precipitating phosphate radicals to generate iron phosphate with the purity of more than or equal to 97%; (2) adjusting the pH value of the first filtrate to 4.7 + / -0.5, adding calcium fluoride seed crystals with the particle size of 50-200mm and CaCl2 (the molar ratio of Ca to F <-> is 0.5: 1-0.6: 1), and carrying out induced crystallization to recover calcium fluoride with the purity of more than or equal to 96%; and (3) adding Ca (OH) 2 (Ca: SO4 < 2-> molar ratio of 1.0: 1-1.2: 1) into the second filtrate, and directionally precipitating sulfate radicals to generate calcium sulfate dihydrate with the purity of more than or equal to 98%. According to the method, the pH and the precipitation sequence are controlled step by step, so that the problem of polyanion competition is solved, the recovery rates of phosphate radical, fluorine ion and sulfate radical respectively reach 98.8%, 96.3% and 97.5%, the content of PO4 < 3-> in purified water is less than or equal to 10 mg.L <-1 >, the content of F <-1 > is less than or equal to 5 mg.L <-1 >, and the content of SO4 < 2-> in purified water is less than or equal to 100 mg.L <-1 >, and the purified water can be directly recycled.

The invention discloses a method for synergistically recycling rare earth-containing coal mine acid wastewater and coal gangue, and relates to the technical field of comprehensive utilization of mineral resources, the method mainly comprises the following steps: S1, arranging a rare earth-rich coal gangue dump leaching field and building a heap; s2, spraying the rare earth-containing coal mine acid wastewater and collecting leachate; s3, separation and enrichment of rare earth elements; and S4, carrying out high-valued treatment on resources such as iron and aluminum in the residual solution. According to the method, valuable resources such as rare earth in the rare-earth-containing coal mine acid wastewater and the rare-earth-rich coal gangue are synergistically recycled, meanwhile, treatment of the coal mine acid wastewater and preparation of the polymeric ferric aluminum sulfate are achieved, the concept of maximum value of comprehensive utilization of resources is achieved, and the treatment process is low in cost and little in environmental pollution.

The present application relates to the technical field of sodium‑ion batteries, and provides a sodium iron sulfate-based composite positive electrode material, and a preparation method therefor and a use thereof. The sodium iron sulfate-based composite positive electrode material has a porosity of 0.1%-10% and a compacted density of 2.1-3 g / cm3; in addition, the sodium iron sulfate-based composite positive electrode material has a specific surface area of 5-12 m2 / g, and a sodium-rich impurity phase in the sodium iron sulfate-based composite positive electrode material has a mass percentage content of 0.1%-1%. The present application helps to improve the performance of batteries, such as the charge / discharge capacity and the initial coulombic efficiency.

The invention belongs to the technical field of electrochemistry, and particularly provides a lanthanum-cerium double-doped sodium ferric sulfate positive electrode material and a preparation method thereof. The material is composed of a matrix and a carbon coating layer coating the matrix, the matrix has a chemical expression of Na6Fe4-x-yLaxCey (SO4) 7, x is greater than or equal to 0.01 and less than or equal to 0.1, and y is greater than or equal to 0.01 and less than or equal to 0.1. The material is prepared through spray drying and high-temperature sintering treatment in sequence, the particle morphology is regular, and the particle size distribution is uniform; the electronic conductivity and Na < + > diffusion rate of the material are remarkably improved by rare earth doping, so that the material has more excellent low-temperature cycle performance, sodium storage performance and the like.

The invention discloses a sulfate-series sodium-ion battery positive electrode material with an expanded structure, a preparation method of the sulfate-series sodium-ion battery positive electrode material and a sodium-ion battery. The general formula of the sulfate-series sodium-ion battery positive electrode material is Na < 6-x > L < x > Fe < 5-y > M < y > (SO4) 8, wherein x is more than or equal to 0 and less than or equal to 0.5, y is more than 0 and less than or equal to 0.5, L is an alkali metal element with the same chemical valence as Na, and M is a transition metal element with the same chemical valence as Fe. According to the positive electrode material disclosed by the embodiment of the invention, the sodium ferric sulfate material with an expanded structure is taken as a main phase, and elements with variable radiuses are introduced into sodium sites and iron sites, so that the material further obtains a pore channel structure and defects with proper sizes, a three-dimensional diffusion channel of sodium ions is expanded, and the volume change in an electrochemical cycle process is inhibited; the structural stability of the material is ensured, so that the material shows relatively high gram volume and relatively good rate capability.

The invention discloses a modified polyferric coagulant and a preparation method thereof, and belongs to the technical field of papermaking wastewater treatment.The polyferric sulfate serves as a main chain and then is combined with carboxylated polyvinyl alcohol, the carboxylated polyvinyl alcohol contains a large number of carboxyl groups, and the carboxylated polyvinyl alcohol and iron ions in polyferric molecules can form stable complexing coordination bonds; kH-570 can generate a polyhydroxy complex after hydrolysis, and active silanol on the surface of the hydrolysis product serves as a carrier with a larger surface area, can be combined with polyferric sulfate and can be subjected to a condensation reaction with hydroxyl and amino on chitosan, so that the molecular weight of the polymer is increased. Compared with a conventional coagulant, the prepared modified polyferric coagulant has the advantages that the selective adsorption performance is increased, the characteristic that PFS carries a large number of positive charges is reserved, meanwhile, molecular chains are increased, the speed of net capturing, sweeping and floc forming is increased, and the coagulation effect is higher.

The invention discloses a carbon nanotube and silver nanowire co-loaded cotton fabric, a preparation method and application, a pretreated cotton fabric is placed in a silane coupling agent solution, and after soaking treatment, washing and drying are performed to obtain a modified cotton fabric; the preparation method comprises the following steps: acidizing carbon nanotubes, and dispersing the acidized carbon nanotubes in deionized water to obtain acidized carbon nanotube dispersion liquid; the preparation method comprises the following steps: mixing a reducing agent, ferric sulfate, silver nitrate, polyvinylpyrrolidone and water, heating to react, centrifuging, washing, and dispersing a product into deionized water to obtain AgNWs dispersion liquid; the modified cotton fabric is soaked in a CNTs / AgNWs dispersion liquid prepared from the acidified carbon nanotube dispersion liquid and the AgNWs dispersion liquid, and the modified cotton fabric is taken out and dried. The cotton fabric is modified through oxysilane, active groups are introduced to the surface of the fabric, and the binding force of the cotton fabric and a conductive material is enhanced. The surface of the fiber is coated with the carbon nanotubes, the silver nanowires are in lap joint to fill gaps, the carbon nanotubes and the silver nanowires form a continuous and complete conductive network on the surface of the cotton fabric, and the conductivity is improved.

The invention discloses a monocrystal sodium ferric sulfate composite electrode material and a preparation method thereof, and belongs to the technical field of sodium ion battery positive electrode materials. Aiming at the problems of low cycle performance and poor conductivity of the current sodium ferric sulfate material, ferrous sulfate heptahydrate is roasted in an inert atmosphere to obtain anhydrous ferrous sulfate (FeSO4). 2, carrying out ball milling, crushing and mixing on anhydrous FeSO4, anhydrous Na2SO4 and the flash graphene according to a certain mass ratio to obtain a mixed precursor; and 3, sintering the roasted precursor material in a rotary tube furnace protected by an inert atmosphere to obtain the single-crystal sodium ferric sulfate composite positive electrode material. According to the preparation method disclosed by the invention, the mixing uniformity of the two raw materials in a quasi-nano scale is improved based on the lubricating and grinding-aiding effects of the flash graphene on a material precursor, and meanwhile, the growth uniformity of the sodium ferric sulfate crystal can be effectively promoted by combining the precise proportion design of FeSO4 and Na2SO4, so that the material with a pure-phase single-crystal structure and excellent sodium storage cycle performance is obtained.

The invention discloses a carbon-coated sodium ferric sulfate positive electrode material, a preparation method thereof and a battery, and the preparation method comprises the following steps: dissolving anhydrous sodium sulfate and ferrous sulfate heptahydrate in a solvent according to a preset proportion, and adding a preset amount of inorganic carbon dispersion liquid to form a uniform suspension; carrying out spray drying on the turbid liquid to obtain a primary coating precursor; dispersing a conductive carbon black material in the solution to obtain a carbon dispersion liquid; putting the primary coated precursor into an aerial fog coating machine, pumping a carbon dispersion liquid into a nozzle, and coating through two-phase flow injection and collision with primary coated precursor powder to obtain a secondary coated precursor; and sequentially calcining, grinding and screening the precursor to obtain the carbon-coated sodium ferric sulfate positive electrode material. The preparation method disclosed by the invention adopts two common industrial treatment modes of spray drying and fluidization coating for preparation, and has the characteristic of easiness in amplification. The fluidization coating can effectively improve the coating uniformity of the solid-phase inorganic carbon on the particle surface.

The invention relates to an egg yolk shell structure ion-doped sodium ferric sulfate positive electrode material, a preparation method and an application thereof, and the material is an egg yolk shell sphere structure carbon composite sodium ferric sulfate positive electrode material formed by doping cations A and B at Na or Na / Fe ion sites of sodium ferric sulfate and enabling anions to occupy part of S-O tetrahedral positions to change the arrangement mode of Fe-O octahedrons of the sodium ferric sulfate, the shell and the inner core of the egg yolk shell sphere are uniform in material, a gap exists between the shell and the inner core, and carbon is uniformly distributed and coated inside and outside the material. The invention also discloses a preparation method and application of the egg yolk shell structure ion-doped sodium ferric sulfate positive electrode material. The material is large in specific surface area, the reversible charge-discharge capacity of an assembled battery is high, and the cycle performance and the high-rate performance are good. The method is low in raw material cost, simple, short in production period and suitable for large-scale continuous production.

The invention discloses a method for recovering a lithium source and an iron source in a lithium iron phosphate battery positive plate, which comprises the following steps of: cutting a dried positive plate material into pieces, putting into a tubular furnace, calcining at high temperature, crushing, sieving and separating aluminum foil pieces to obtain lithium iron phosphate positive fine powder; the method comprises the following steps: mixing the lithium iron phosphate positive electrode fine powder with an acidic ingredient, separating and deslagging to obtain a filtrate, dropwise adding an H2O2 solution, adding a NaOH solution to generate a precipitate, and carrying out suction filtration to obtain a residue Fe (OH) 3 colloid and a filtrate Li (OH) solution; and further treating the separated slag by dissolving with dilute sulfuric acid, dropwise adding an ammonium phosphate solution into the generated ferric sulfate salt solution, and adding ammonia water NH3.H2O to adjust the pH value to be 2-3 to form ferric phosphate precipitate, thereby obtaining ferric phosphate powder. And introducing CO2 gas into the filtrate for 2 hours to form white emulsion, thereby obtaining the lithium carbonate. Recycling of the lithium source and the iron source of the waste lithium iron phosphate battery has important significance and wide prospects in the aspects of environmental protection, economy and resource sustainability.