1173 results about "Iron phosphate" patented technology

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

The invention discloses a reaction kettle device for synthesis of an iron phosphate material, and particularly relates to the technical field of synthesis of battery materials, and the device comprises a kettle body, a driving motor, a transmission disc and a turbo-type paddle. A sealing cover is arranged at the top of the kettle body, a driving motor is connected with a rotating shaft, an anchor blade is arranged below the rotating shaft, and the bottom realizes turbine blade lifting and sleeve guide limiting through transmission of a piston cavity and compressed gas; and a ratchet wheel on the outer wall of the rotating shaft is meshed with a pawl in the transmission disc in a one-way mode, and intermittent wall scraping is achieved. According to the device, dead angles are broken through synergistic stirring of the double blades, the mixing uniformity and the reaction rate are improved, materials adhering to the wall are efficiently removed through intermittent wall scraping, the stable reaction environment is guaranteed through multiple sealing, the structure is flexible to adjust, maintenance is convenient and fast, efficient and high-quality synthesis of the iron phosphate material can be achieved, and the device is suitable for industrial large-scale production.

The invention belongs to the technical field of batteries, and discloses a carbon-coated modified lithium manganese iron phosphate positive electrode material and a preparation method and application thereof, and the carbon-coated modified lithium manganese iron phosphate positive electrode material comprises carbon-coated modified lithium manganese iron phosphate positive electrode material particles, the carbon-coated modified lithium manganese iron phosphate positive electrode material particle comprises a lithium manganese iron phosphate core, a first carbon coating layer and a second carbon coating layer, wherein the first carbon coating layer is positioned between the lithium manganese iron phosphate and the second carbon coating layer; the graphitization degree of the first carbon coating layer is greater than that of the second carbon coating layer. The carbon-coated modified lithium manganese iron phosphate positive electrode material has relatively high conductivity, compaction density and the like, and a battery using the carbon-coated modified lithium manganese iron phosphate positive electrode material has relatively high charge-discharge rate, excellent energy density, excellent capacity and the like.

The invention provides a moniliella malayi and a fungicide and application thereof, and relates to the field of microorganisms. The acer rubrum is specifically acer rubrum RA, and the preservation number of the acer rubrum RA is CGMCC (China General Microbiological Culture Collection Center) No.35889. The acer rubrum RA can be used for preparing the acer rubrum. The strain has the capability of decomposing inorganic phosphorus, is wide in phosphorus-dissolving range, can decompose tricalcium phosphate, iron phosphate and aluminum phosphate, and particularly still has very strong capability of decomposing inorganic phosphorus under a low-temperature condition; the strain has the capability of producing siderophore and IAA at low temperature; the strain has an inhibition effect on various pathogenic bacteria causing field crop diseases, and can inhibit diseases such as corn root rot, sorghum leaf spot or wheat root rot; the strain can be colonized in a soil environment of 5-40 DEG C, a microbial inoculum prepared from the strain can promote crop growth, the crop yield is remarkably improved, and high yield can be achieved even if the usage amount of phosphate fertilizer is reduced.

The invention relates to the technical field of evaporative crystallization control, in particular to an iron phosphate wastewater low-energy-consumption evaporative crystallization control system which comprises a preheating module, an evaporation concentration module, a steam circulation module, a steam detection module, a salt separation and recovery module and a low-energy-consumption control module. The evaporation and concentration module realizes water gradient evaporation and feed liquid concentration through evaporation units which are connected in series in multiple stages; the steam circulation module integrates a steam compressor and a steam ejector, leading equipment can be intelligently switched according to system requirements, and dual-mode operation of mechanical compression and thermal compression is achieved. The steam detection module judges the equipment state in real time by analyzing the rotating shadow and vibration waveform of the compressor and the audio waveform of the ejector; the salt separation and recovery module is used for continuously separating ammonium sulfate and monoammonium phosphate, recovering crystals and recovering condensed water for preheating; the low-energy-consumption control module dynamically adjusts the operation mode and steam parameters, and energy-saving optimization and stable control of the whole process are achieved.

The invention discloses a method for separating and recycling phosphorus, iron and lithium in battery black powder, and relates to the technical field of battery recycling. The method comprises the following steps: carrying out acid leaching on battery black powder to obtain a battery black powder leaching solution and filter residues; an oxidizing agent is added into the battery black powder leaching solution, the pH of the solution is adjusted to 1.8-2.5, solid-liquid separation is conducted after the reaction is completed, and iron phosphate sediment and a lithium-containing solution are obtained; adjusting the pH value of the lithium-containing solution to 10-12, and carrying out solid-liquid separation after the reaction is completed to obtain a metal precipitate and a lithium sulfate solution; dissolving the iron phosphate precipitate in a sulfuric acid solution, adding a reducing agent to reduce ferric iron into ferrous iron, separating out ferrous sulfate by adopting an alcohol precipitation method or an ammonium sulfate crystallization method, and performing solid-liquid separation after the reaction is completed to obtain ferrous sulfate precipitate or ammonium ferrous sulfate crystals and mother liquor; and evaporating and concentrating the mother liquor, and extracting to obtain a phosphoric acid solution. According to the method, the three elements of phosphorus, iron and lithium in the battery black powder can be recycled, and the environmental problem caused by stacking of the lithium extraction slag can be avoided.

The invention discloses a long-life lithium manganese iron phosphate positive electrode material and a preparation method thereof, and relates to the technical field of lithium ion battery positive electrode materials. The long-life lithium manganese iron phosphate positive electrode material comprises lithium manganese iron phosphate, a middle coating layer and a carbon coating layer, the surface of the lithium manganese iron phosphate is coated with the middle coating layer, the surface of the middle coating layer is coated with the carbon coating layer, the middle coating layer contains metal fluoride and aluminum-containing sinter, and the aluminum-containing sinter comprises aluminum oxide and lithium metaaluminate. The synergistic coating of the middle coating layer and the carbon coating layer can effectively reduce the contact between the positive electrode material and an electrolyte, inhibit the generation of surface side reactions, improve the stability of the electrode material structure, and have low manganese dissolution and excellent cycle life.

The invention relates to a preparation method of iron phosphate, and discloses low-sulfur porous iron phosphate and a preparation method thereof. The preparation method of the low-sulfur porous iron phosphate comprises the following steps: providing a mixed solution which contains iron ions, phosphate ions and sulfuric acid; controlling the temperature of the mixed solution to be 60-80 DEG C, and preserving heat and aging for 10-20 hours to obtain slurry containing iron phosphate; extracting a solid from the slurry and washing for multiple times; the washed solid is subjected to microwave drying, the drying temperature is set to be 350-400 DEG C, and the frequency is set to be 2400-2500MHz. The preparation method is short in technological process and low in energy consumption, and the prepared iron phosphate is low in sulfur content, is of a porous structure, is applied to a battery, facilitates permeation of an electrolyte and intercalation and deintercalation of lithium ions, and can enable the battery to have high circularity.

The invention discloses a niobium-doped and carbon nanotube continuously coated lithium iron nickel phosphate material and a preparation method thereof, and belongs to the technical field of lithium ion battery positive electrode materials. The niobium source and the phosphorus source are added step by step, the concentration gradient distribution of the niobium element in the material is realized, and niobium is preferentially doped in the [100] crystal orientation through three-section temperature control sintering, so that the bulk phase conductivity and the lithium ion mobility are remarkably improved, and the capacity loss caused by excessive doping is avoided while the lattice structure is stabilized. In addition, the carbon nanotubes and the nitrogen-containing carbon source have a synergistic effect, Li-N-C covalent bonds are formed on the surface of the material, the interface stability is enhanced, the interface side reaction is effectively inhibited, and the surface conductivity is improved. According to the method, through double modification of doping and coating, the problems of low conductivity and poor cycling stability of the lithium iron nickel phosphate material are successfully solved, and the final product shows excellent rate capability and long cycle life.

The invention relates to the technical field of preparation of battery materials, and discloses a method for synthesizing iron phosphate through continuous oxidation, which comprises the following steps: oxidation: oxidizing a ferrous solution by adopting oxygen-containing gas to obtain a ferric iron solution; synthesizing iron phosphate: reacting the ferric iron solution with a phosphorus source to obtain amorphous iron phosphate; and crystal transformation and roasting: carrying out crystal transformation and roasting on the amorphous iron phosphate to obtain the iron phosphate. The iron phosphate material prepared by the invention is oxidized by adopting the oxygen-containing gas, so that compared with hydrogen peroxide adopted in the prior art, the cost is lower, and the specific surface area and the tap density of the prepared iron phosphate material are higher.

The invention relates to a positive electrode material and a preparation method thereof, a sodium-ion battery positive plate and a sodium-ion battery. The positive electrode material comprises a mixed sodium iron phosphate matrix and a double-carbon heterostructure penetrating through the inside and the outside of the mixed sodium iron phosphate matrix, the general formula of the mixed sodium iron phosphate matrix is Na4Fe3 (PO4) 2P2O7, and the double-carbon heterostructure comprises a conductive carbon material and an organic carbon source precursor pyrolysis product, the mixed sodium iron phosphate matrix is foamed by gas generated by pyrolysis of the organic carbon source precursor to form a three-dimensional porous structure, and the surfaces of particles of the mixed sodium iron phosphate matrix are coated with pyrolysis products of the organic carbon source precursor; the conductive carbon material penetrates through the three-dimensional porous structure and is connected with the mixed sodium ferric phosphate matrix particles coated with the organic carbon source precursor pyrolysis product, so that a three-dimensional porous interconnected conductive network is formed. According to the positive electrode material, the sodium storage specific capacity can be ensured, the electronic conductivity of the NFPP material is effectively improved, and the rate capability and the cycling stability of the NFPP material are improved.

The invention belongs to the field of positive electrode materials, and particularly relates to a core-shell ferromanganese phosphate precursor, a modified lithium ferric manganese phosphate material, a preparation method and application of the modified lithium ferric manganese phosphate material and a lithium ion battery. The core-shell ferromanganese phosphate precursor comprises a core and a shell wrapping the core, and the core is Fe3 (PO4) 2; the shell is MnxFe1-x (PO4) y (ferromanganese phosphate), x is more than or equal to 0.1 and less than or equal to 0.9, and y is more than or equal to 0.67 and less than or equal to 0.75. The invention provides a core-shell ferromanganese phosphate precursor which takes Fe3 (PO4) 2 as a core and MnxFe1-x (PO4) y as a shell, and when the core-shell ferromanganese phosphate precursor is used for preparing lithium ferromanganese phosphate, the problem of component segregation is solved, and the Jahn-Teller effect of manganese is reduced; especially for subsequent doping and coating, doping segregation is expected to be reduced, coating interface impedance is reduced, and rapid charging of the prepared material and cycling stability under large current can be remarkably enhanced.

The invention belongs to the field of batteries, and particularly relates to a positive plate, a lithium battery and a preparation method thereof. Comprising a positive current collector and an active coating coated on the surface of the positive current collector, the active coating comprises a first coating close to the current collector and a second coating far away from the current collector; the first positive electrode active material is a mixture of monocrystal lithium manganese iron phosphate and a lithium-rich manganese-based material, and the second positive electrode active material is aggregate lithium manganese iron phosphate. The positive plate adopts a double-layer coating design, the first coating close to one side of the current collector is made of high-manganese lithium manganese iron phosphate in a nano small particle form, the second coating far away from the current collector is made of a low-manganese lithium manganese iron phosphate material in an aggregate form, and a gradient manganese distribution design with high manganese in the inner layer and low manganese in the outer layer is constructed; the manganese dissolution risk can be effectively reduced, and the cycle performance is improved. And meanwhile, the energy density of the battery can also be improved by using the high-manganese-content lithium manganese iron phosphate.

The invention discloses a method and system for preparing iron phosphate through an iron powder method based on oxygen micro-nano bubbles and application, and belongs to the technical field of iron phosphate preparation. The method comprises the following steps: pulping iron powder and pure water, injecting the pulped iron powder and pure water into an iron dissolving reaction kettle, adding phosphoric acid, and carrying out a leaching reaction under corresponding preset conditions to obtain a first solution containing ferrous dihydrogen phosphate; after solid-liquid separation, pumping the second filtrate into an oxidation kettle, introducing oxygen micro-nano bubbles by using a micro-nano bubble generator, and carrying out oxidation reaction on the second filtrate and ferrous dihydrogen phosphate under corresponding preset conditions to obtain a third solution containing amorphous hydrated iron phosphate and phosphoric acid; pumping the third solution into an aging kettle, and aging the amorphous ferric phosphate hydrate to generate ferric phosphate dihydrate, so as to obtain a fourth solution; after solid-liquid separation, washing the iron phosphate dihydrate, and carrying out flash evaporation drying on a filter cake to obtain dry powder; and roasting and dehydrating to finally obtain the battery-grade anhydrous iron phosphate. According to the method, reaction conditions are accurately controlled, oxygen micro-nano bubbles are innovatively introduced for oxidation, and a new way is provided for preparing high-performance products.

The invention discloses a vanadium iron-site doped iron phosphate material and a preparation method, and relates to the technical field of lithium ion battery positive electrode material preparation, pure water is used as a base solution, and a vanadium salt solution with the pH value of 2.0-3.0, a ferrite solution with the pH value of 1.0-2.5 and a phosphorus-oxygen mixed solution with the pH value of 5.0-7.0 are simultaneously added into a reaction kettle in a three-strand parallel flow mode for a co-precipitation reaction. By controlling the acid environment of a key solution system, reduction of metavanadate radicals or generation of ferric vanadate precipitates is effectively inhibited, and vanadium elements are successfully and uniformly doped to iron sites of iron phosphate crystal lattices; the mass ratio of iron to phosphorus in the obtained iron phosphate material is stabilized at 95-98%, the doping amount of vanadium is 100-10000 ppm, and the vanadium is uniformly distributed. Lithium iron phosphate prepared by taking the material as a precursor has higher discharge capacity and compaction density, and the electrochemical performance of a lithium ion battery is remarkably improved.

The invention discloses battery-grade iron phosphate as well as a preparation method and application thereof. The battery-grade iron phosphate is of a core-shell structure, D50 is 20-40 [mu] m, the core is 50% of an internal area in the radius direction, the shell is the other external area, the porosity of the core is 1%-10%, the porosity of the shell is 30%-70%, and when the battery-grade iron phosphate is used for preparing a lithium iron phosphate material, natural grading can be achieved without iron phosphate compounding; the prepared lithium iron phosphate material has high compaction density.

The present application discloses a lithium iron manganese phosphate composite material, a preparation method therefor as well as a secondary battery. The lithium iron manganese phosphate composite material sequentially comprises a core, a first coating layer and a second coating layer, wherein the core comprises LixMnyFe1-y-zDzPO4 material, 1≤x≤1.05, 0<y<1, 0≤z<1, and D is a metal element; the first coating layer comprises LiaAlbMcOd material, 0<a≤1, 0<b<1, 0<c<1, 0<d<3, M comprises at least one of Y element, Zr element and Mg element, and the second coating layer comprises carbon. The method for preparing the lithium manganese iron phosphate composite material comprises: providing a core, which comprises a material having a chemical general formula LixMnyFe1-y-zDzPO4; preparing a first coating layer on the outer surface of the core utilizing an atomic layer deposition technology, the first coating layer comprises a material having a chemical general formula LiaAlbMcOd; and preparing a second coating layer on the outer surface of the first coating layer, the second coating layer comprises carbon.

The invention provides a preparation method and application of an ultra-high-pressure solid-state lithium iron phosphate material, and belongs to the field of lithium batteries. The method comprises the following steps: respectively mixing iron phosphate with a high iron-phosphorus ratio and iron phosphate with a low iron-phosphorus ratio with a lithium source, an additive and a carbon source, carrying out sanding, spray granulation and sintering treatment to obtain a precursor A and a precursor B, and carrying out secondary sintering on the precursor B to obtain a precursor C; and finally, mixing the precursor A and the precursor C in proportion, and crushing to obtain the ultra-high pressure solid type lithium iron phosphate positive electrode material. According to the invention, the coordination of high compaction density and excellent electrochemical performance of the lithium iron phosphate positive electrode material is realized by constructing a grading structure of a large-particle skeleton and small-particle filling and optimizing a crystal structure by combining a two-step sintering process, and the lithium iron phosphate positive electrode material is suitable for the field of high-capacity lithium ion batteries.

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.

The invention relates to the technical field of lithium ion batteries, and provides a method for preparing lithium iron phosphate by using a titanium dioxide byproduct ferrous sulfate and application. The invention relates to a method for preparing lithium iron phosphate by using a titanium dioxide byproduct ferrous sulfate, which comprises the following steps: dissolving the titanium dioxide byproduct ferrous sulfate, adding a purifying agent for purification treatment, and filtering to obtain a purified ferrous sulfate solution; the purified ferrous sulfate solution serves as electrolyte, Fe < 2 + > is partially oxidized into Fe < 3 + >, phosphoric acid is added into the obtained mixed valence iron solution, the pH is adjusted, and iron phosphate precursor slurry is formed through aging; mixing the iron phosphate precursor slurry with an ethanolamine-water mixed solution of lithium hydroxide, and carrying out a reaction in a microwave reactor to obtain a lithium iron phosphate precursor suspension; and crystallizing the lithium iron phosphate precursor, and simultaneously introducing a carbon source steam and a silicon source steam to carry out gas-phase surface modification to obtain the lithium iron phosphate material. According to the invention, the raw material purity is improved, the powder structure is improved, and the long-cycle stability is improved.

The invention relates to an electrochemical element comprising: -a negative electrode comprising an active material; -a 2024 / 022807 positive electrode comprising an active material comprising a lithium manganese iron phosphate; -a gel electrolyte comprising a matrix which is a polymer obtained by crosslinking a monomer comprising at least two acrylate groups, whereby a liquid mixture comprising at least one solvent, at least one lithium salt and a free-radical polymerisation thermal initiator is incorporated therein.

The invention provides a ferric sodium pyrophosphate positive electrode material, a preparation method thereof and a sodium ion battery. The ferric sodium phosphate pyrophosphate positive electrode material comprises a ferric sodium phosphate pyrophosphate / carbon composite material core and a carbon coating layer, the chemical formula of the sodium ferric pyrophosphate / carbon composite material core is Na (4-x) AxFeyB (2.91-y) (PO4) 2-z / 3P2O7Fz / C, x is greater than or equal to 0.01 and less than or equal to 1, y is greater than or equal to 2.7 and less than 2.91, z is greater than or equal to 1 and less than or equal to 3, A comprises any one or a combination of at least two of Li, K or Ca, and B comprises any one or a combination of at least two of Mg, Al, Zn, V, Co, Mn, Zr, Ti, Cu or Y. According to the invention, the conductivity, rate capability, cycle life and stability of the sodium ferric phosphate pyrophosphate positive electrode material are comprehensively improved through the bulk phase composite carbon and surface carbon-coated dual carbon structure in combination with regulation and control of the sodium ferric phosphate pyrophosphate component.

A lithium manganese iron phosphate cathode material, including a first lithium manganese iron phosphate particle and a second lithium manganese iron phosphate particle. A molar ratio of Mn to Fe in the first lithium manganese iron phosphate particle is greater than or equal to 1. A molar ratio of Mn to Fe in the second lithium manganese iron phosphate particle is smaller than or equal to the molar ratio of Mn to Fe in the first lithium manganese iron phosphate particle. A particle size of the first lithium manganese iron phosphate particle is smaller than or equal to a particle size of the second lithium manganese iron phosphate particle. A preparation method of the lithium manganese iron phosphate cathode material and an application thereof are provided.

The application provides a preparation method of a precursor pre-adsorption sodium-supplemented sodium iron phosphate pyrophosphate positive electrode material, uses hydrated iron phosphate as a precursor, and places the precursor in a sodium salt of an organic weak acid sodium supplement solution for impregnation adsorption, and after drying, is mixed with a sodium source, a phosphoric acid source, a pyrophosphoric acid source and a carbon source, and is sintered in an inert atmosphere to obtain a pre-sodium-supplemented Na4Fe3(PO4)2P2O7 / C material. The application also provides a sodium iron phosphate pyrophosphate positive electrode material prepared by using the above method, and a sodium ion battery comprising the material. By impregnating and adsorbing the sodium salt of the organic weak acid sodium supplement on the industrial precursor of the sodium iron phosphate pyrophosphate, the nanoscale dispersion of the sodium supplement is achieved, the toxicity and high gas production of the traditional sodium supplement are avoided from the root, the process is adapted to the existing industrial production line, the first coulomb efficiency and the cycle stability of the sodium iron phosphate pyrophosphate positive electrode material are effectively improved, and the industrial application is promoted.

The application relates to the technical field of chemical preparation, and particularly relates to a liquid monoammonium phosphate and iron phosphate production system. The system comprises a mother liquor treatment device, a pH adjusting tank, a purified phosphoric acid storage tank, a liquid monoammonium phosphate storage tank and an iron phosphate production device; the output end of the mother liquor treatment device is connected with the first input end of the pH adjusting tank, the output end of the purified phosphoric acid storage tank is connected with the second input end of the pH adjusting tank, and the purified phosphoric acid and the mother liquor to be adjusted are injected into the pH adjusting tank; the mixed reaction area of the pH adjusting tank is configured to neutralize the mother liquor to be adjusted and the purified phosphoric acid according to a preset ratio to generate liquid monoammonium phosphate; the input end of the liquid monoammonium phosphate storage tank is connected with the output end of the pH adjusting tank, the output end of the liquid monoammonium phosphate storage tank is connected with the raw material inlet of the iron phosphate production device, and the iron phosphate production device is configured to synthesize iron phosphate by taking the liquid monoammonium phosphate as a raw material. The application has the beneficial effects of simplifying a production process and reducing energy consumption.

The invention provides a preparation method and application of a lithium manganese iron phosphate composite material, and the preparation method comprises the following steps: (1) mixing a manganese source, an iron source, a phosphorus source, lithium carbonate, glucose and a dopant in proportion, sanding and spraying to obtain a yellow material; dividing the yellow material into two parts, respectively sintering and mixing at high temperature and low temperature to obtain a mixed sintered material; (2) mixing the mixed sintered material, a carbon source and an additive according to a ratio, sanding, spraying and sintering to obtain a lithium manganese iron phosphate sintered material; and (3) uniformly mixing the lithium manganese iron phosphate sintered material and lithium manganate, and carrying out secondary sintering to obtain the lithium manganese iron phosphate composite material. The whole preparation process is simple, the raw material utilization rate is high, byproducts or material waste is avoided, and the method has good industrialization prospects.

The application discloses a method for recovering nickel and phosphorus from electroless nickel plating waste liquid, and the method comprises the following steps: preparing nickel sulfate through extraction and stripping, and preparing iron phosphate through Fenton oxidation and precipitation; compared with the prior art, the method is characterized in that the waste liquid is pretreated, insoluble solid particles in the waste liquid are removed, emulsification of an extractant caused by particles in a subsequent extraction process is prevented, damage to extraction oil is avoided, and the extraction efficiency is ensured; in addition, the extractant used in the method can be recycled, secondary pollution is avoided, and the method is economical and practical; in the method, main pollutants in waste water are all converted into important chemical raw materials, recycling is realized, sulfuric acid and Fenton reagents used are all converted into terminal products, difficulty of end waste water treatment is not increased, clean production is met, the treatment cost is low, the product has high added value, and the method has strong practicability.

The application discloses a Fe self-catalytic in-situ lithium supplementing and graphite carbon-coated lithium manganese iron phosphate positive electrode material and a preparation method thereof, and belongs to the technical field of lithium batteries. 2+ Catalyze PAN to generate sp 2 Carbon, LiBOB-Li2O microcapsule in-situ lithium supplementing, and then ultra-high speed quenching to obtain the product. 2+ Self-catalysis, integration of carbon coating and in-situ lithium supplementing, greatly improving the conductivity, the first charge-discharge efficiency and the rate performance of the material, simple and controllable process, suitable for industrial production, and the prepared material has high compacted density and excellent cycle stability.

The invention discloses a method for preparing lithium iron manganese phosphate by obtaining a high-performance precursor from waste lithium iron phosphate. According to the method disclosed by the invention, the chelating effect of phytic acid and ferric ions is utilized, so that an organic carbon source is introduced into hydrated iron phosphate precipitated from the waste lithium iron phosphate leaching solution, the fusion growth of iron phosphate particles is effectively prevented in the subsequent high-temperature roasting process, and the high-performance lithium manganese iron phosphate precursor is obtained from the waste lithium iron phosphate. The method comprises the following steps: dissolving waste lithium iron phosphate powder in a sulfuric acid solution, then adding a small amount of a phytic acid solution and ferric sulfate with a corresponding molar weight, precipitating and calcining at a high temperature to obtain dehydrated iron phosphate (FP-PA) with a limited particle size; when the material is applied to synthesis of a lithium manganese iron phosphate positive electrode material, the particle size of the positive electrode material can be effectively controlled, and the specific capacity and cycle performance of a battery are improved. The method is easy to operate and high in repeatability, and a new way is provided for treating waste lithium iron phosphate with economic benefits and excellent performance.

The invention discloses a method for regulating and controlling the quality of an iron phosphate finished product based on iron phosphate production line process materials, which comprises the following steps of: adding the iron phosphate production line process materials such as cold kiln leaked materials, demagnetized materials, dedusted materials, vibrating screen falling materials, packaging falling materials, hot kiln wall sticking materials and the like into the preparation process of the iron phosphate finished product in stages; according to the method, on one hand, waste is recycled, and resource waste is reduced; on the other hand, by means of the process materials and a regulation and control mode of step-by-step addition, the quality of the finished product of iron phosphate can be effectively and benign improved, and various indexes and morphological structures of the finished product of iron phosphate are optimized, so that the obtained dihydrate and anhydrous iron phosphate particles are more regular, and the core requirements of dispersity of the dihydrate iron phosphate and fluidity of the anhydrous iron phosphate are met respectively; the crystal form regulation and the reaction efficiency are both improved.