2026 results about "Iron phosphate" patented technology

The invention discloses a precipitation method for preparing nanometer level iron phosphate lithium coated with carbon. The method comprises the following steps: firstly, weighing iron salt, deionized water and a compound of metallic elements; after the stirring and the mixing are performed, adding a phosphorous compound and citric acid diluted with water to the mixture; after the stirring is performed again, adding a precipitation agent to the mixture and controlling to the neutrality; stirring to react in a container, and after the static placement, respectively adding the deionized water, a carbon source and lithium salt to mix uniformly after the precipitate is filtered and washed; stirring again to react, and drying the water at 30 to 160 DEG C and warming up at the heating rate under the protection of non-oxidized gas after a product is crashed; baking at a constant temperature of 450 to 850 DEG C, cooling down to a room temperature at a cooling rate or with a stove, and finally obtaining the nanometer level ferric phosphate lithium coated with the carbon after crashing is performed. The precipitation method has the advantage that the raw material cost and the processing cost are low because bivalent iron is taken as the raw material. The iron phosphate lithium prepared by using the process has the characteristics of good physical processing performance and good electrochemistry performance, and is suitable for industrialized production.

The invention relates to a synthesized recovery method for waste positive plates of iron phosphate lithium batteries. The method comprises the following steps: collected waste positive plate material is mechanically crashed into fragments; the fragments are positioned in a welding furnace which is protected by vacuum atmosphere, inert gases and/or reducing gases and/or nitrogen and are heat processed in the temperature of 150-750 DEG C; aluminum foil basal bodies are separated from the fragments after heat process by adopting mechanical separation or ultrasonic concussion to obtain a mixture of iron phosphate lithium positive material, conduction agent and caking agent giblets; the mixture of iron phosphate lithium anode material, conduction agent and caking agent giblets is roasted for 8-24 hrs in 80-150 DRG C; the mixture after roasting is classified to control the grain diameter of the powder material to be not more than 20 microns, and the D50 is controlled to be 3-10 microns so as to obtain iron phosphate lithium positive recovery material. The method has simple technique, takes effect fast and reduces the material consumption and production cost of a manufacturer.

The invention discloses a method for recovering Al, Fe and Li in waste lithium iron phosphate battery positive pieces through an acid-alkali leaching process. The method comprises the following steps: dismounting the lithium iron phosphate battery positive pieces, dissolving the positive pieces by using an alkali, filtering, and dissolving obtained filter residues by a mixed acid solution for making Fe exist in an iron phosphate precipitate form and be separated from impurities comprising carbon black and the like and a lithium-containing solution; adding the lithium-containing solution to a 95DEG C saturated sodium carbonate solution for precipitation to obtain lithium carbonate; and adding an acid to obtain an iron-containing precipitate for leaching iron ions, and adding an alkaline solution to obtain Fe(OH)3. Al, Fe and Li in the waste lithium iron phosphate battery positive pieces are simply and effectively recovered through using low-concentration acids and alkalis and routine chemicals, and raw materials having economic benefits are recovered through using simple and effective equipment and the method.

The invention discloses a method for selectively recycling lithium from lithium iron phosphate waste through a direct oxidization method. The method is characterized by comprising the steps that the lithium iron phosphate waste is added into a water solution, meanwhile, an oxidizing agent is added, stirring is carried out, lithium iron phosphate and the oxidizing agent react to generate iron phosphate, lithium ions enter the solution, and therefore a pure lithium-containing solution and iron phosphate solids are obtained. The adopted oxidizing agent comprises one or a mixture of persulfate, ozone, oxygen, pypocholoride and hydrogen peroxide. The molar weight of the oxidizing agent is 0.6-20 times that of lithium iron phosphate. The lithium-containing solution can be directly used for preparing a high-purity lithium product. According to the method, efficient and selective leaching of lithium can be achieved simply by adding a certain amount of oxidizing agent, and the method is mild in reaction condition, short in process and simple in equipment.

The invention relates to a method for recycling battery-grade iron phosphate in a lithium iron phosphate battery and preparing a lithium iron phosphate positive material by utilizing a waste lithium ion phosphate battery, and relates to a method for recycling a battery and preparing the battery positive material by utilizing the waste battery recycled material, solving the problems of the traditional method for recycling the LiFePO4 lithium ion battery positive electrode that the purity of the obtained element or substances is low and the obtained element or substances cannot be used for preparing the LiFePO4 lithium ion battery positive electrode. The method comprises the steps: I, crushing a positive pole piece, and carrying out heat treatment; II, dissolving the crushed positive pole piece in an acid solution; III, charging a surface active agent; IV, charging an alkaline solution, thereby obtaining a battery-grade iron phosphate; V, charging sodium carbonate to obtain a lithium carbonate; VI, mixing iron phosphate, lithium carbonate and a carbon source reduction agent; and VII, calcining. In the process for recycling the battery-grade iron phosphate in the lithium iron phosphate battery and preparing the lithium iron phosphate positive material by utilizing the waste lithium iron phosphate battery, no secondary pollution is produced, and the comprehensive and high-added-value recycling of the waste lithium iron phosphate battery can be realized.

The invention discloses a mixed positive electrode material, a positive plate using the same, and a lithium ion battery. The mixed positive electrode material comprises the following component by weight: 50-90 parts of a nickel-cobalt-manganese ternary material and 10-50 parts of lithium-manganese-iron phosphate. The mixed positive electrode material provided by the invention combines the nickel-cobalt-manganese ternary material with high energy density and lithium-manganese-iron phosphate with high safety performance, and plays complementary advantages of nickel-cobalt-manganese and lithium-manganese-iron phosphate, so that comprehensive performances of the positive electrode active material are improved. The positive plate prepared by using the mixed positive electrode material increases the safety performance and cycle performance of the lithium ion battery, increases average voltage of the lithium ion battery, and keeps relatively high energy density; and the lithium ion battery using the positive plate has excellent electrochemical performances, high energy density and high safety performances and long cycle life, and is suitable for popularization and application.

The invention discloses a method for preparing spherical lithium iron phosphate by adopting oxidation control crystallization-carbon thermal reduction. The preparation method comprises the steps of conducting reaction among a mixed water solution of bivalence malysite and phosphoric acid, an aqueous solution of ammonia and an oxidant; synthesizing a spherical precursor of a spherical hydration iron phosphate through the process of oxidation control crystallization; washing; drying; pre-burning for dewatering; mixing with lithium carbonate and a carbon source; and obtaining the lithium iron phosphate through high temperature carbon thermal reduction under the protection of inertial or reducing atmosphere. By using the preparation method, the spherical lithium iron phosphate, an anode material of a lithium ion battery, is prepared, and has high bulk density and high volume specific capacity. The average grain size of the spherical lithium iron phosphate is between 6 and 8 mum, the electric discharge specific capacity thereof for the first time can reach up to 145-150mAh/g at the room temperature of 0.5C.

A method of treating, in wastewater purification, sludge containing organic matter, divalent iron and phosphorus, in which the sludge that is treated is made to contain dissolved iron and phosphorus at a molar ratio Fe:P of above 1:1, the sludge is treated at 0-100° C. with an acid at a pH of 1-5 for dissolution of divalent iron and phosphorus from the sludge, the sludge is supplied with an oxidiser selected from hydrogen peroxide and percompounds, wherein divalent iron is oxidised by Fenton's reaction to trivalent iron, and (i) trivalent iron is precipitated as trivalent iron phosphate (ii) free radicals with a deodorisation and sanitation effect are formed by Fenton's reaction, the sludge is then dewatered at a pH of at most 7, and the aqueous solution obtained in dewatering is recirculated to the wastewater purification.

In one aspect of the invention, methods of synthesizing iron phosphate precursors and lithium iron phosphate active material usable for a lithium secondary battery include the steps of first forming fine particle iron phosphate precursors hydrated and anhydrous, then forming electrode active material lithium iron phosphate with said iron phosphate precursors. The unique methods are generally efficient and cost effective, as well as stable and scalable for a high performance electrode active material with high capacity, good discharge profile, high electronic conductivity, as well as long cycle life.

The invention discloses a recovery method for a cathode material of a waste lithium iron phosphate battery. The recovery method comprises the following steps: firstly, placing a positive plate obtained through disassembly of the waste lithium iron phosphate battery in an ultrasonic machine containing a dilute alkali liquor to be processed, so that a lithium iron phosphate material is separated from an aluminum foil; then, drying the lithium iron phosphate material, after that, performing acid leaching under a normal-temperature condition, and controlling the quantity of an acid solution to ensure that the pH of the solution is 2.5-6.5 after finish of a reaction and iron exists in insoluble residues in the format of iron phosphate, wherein the leaching rate of lithium is more than 97% and the leaching rate of iron is less than 0.1%; and performing filtering to obtain a filtrate and insoluble iron phosphate, performing heat treatment on the insoluble residues to remove organics so as toobtain ferric phosphate, and after purification and enrichment of the filtrate, adding trisodium phosphate for a reaction to obtain lithium phosphate. In the whole recovery process, the yields of lithium and iron are respectively 96% and 99.5%. The recovery method has the advantages that used equipment is simple, the technological process is short, and valuable raw materials are efficiently recovered.

The invention relates to a method for preparing nano iron phosphate, belonging to the technical field of the preparation of lithium ion battery cathode materials. The method is characterized by comprising the following steps: inputting an alkaline aqueous solution and a mixed solution formed by one of phosphoric acid or a soluble phosphate solution, one of a water-soluble ferrous salt solution and an oxidant or a ferric salt solution and a water-soluble dispersing agent into a rotating packed bed layer by a metering pump at a certain feeding speed; regulating the rotating speed of the rotating packed bed and controlling the pH value of the reaction system by an alkaline solution; discharging nano iron phosphate particles generated by reaction crystallization from a discharge hole of the rotating packed bed along with the mixed solution; and filtering, washing and drying the nano iron phosphate particles to obtain nano iron phosphate (FePO4.2H2O) powder. The method is simple and has easy operation and high efficiency, and the prepared iron phosphate reaches the nano grade, has uniform particle size and narrow distribution range and is suitable for industrialized production. The nano iron phosphate is a good precursor material for preparing lithium iron phosphate which is used as a cathode material of high-power type lithium ion batteries.

The invention discloses a rapid forming process of an iron phosphate lithium battery. The rapid forming process comprises the following steps: vacuumizing after the battery is assembled, and injecting electrolyte by several times, and sealing the battery; putting the battery into a thermostat, standing for 8-12 hours at 45-50 DEGC, turning or rotating the battery in a standing process so as to putting each face of the battery downwards for a certain time; after the standing, carrying out ultrasonic treatment on the battery for 10-20 minutes; putting the battery on a cabinet, and carrying out low-current step type charging excitation and intermittent pulse discharge on the battery; after the charging is finished, carrying out deflation and one time of vacuumizing on the battery in a glove box, and carrying out sealing, ageing and capacity grading. According to the rapid forming process, firstly a diaphragm, an anode piece and a cathode piece of the battery are adequately infiltrated by virtue of the electrolyte, and then the battery is simultaneously subjected to high-current step type charging and intermittent pulse discharge, so that the time of the forming procedure is substantially shortened, the equipment loss is reduced, the performance of the formed battery is excellent, and the formed battery has no difference from a battery formed by virtue of a traditional forming process.

The invention relates to a method for recycling lithium carbonate from a lithium iron phosphate waste material, and belongs to the technical field of waste lithium oil battery recycling. The technical problem to be solved by the invention is that a method for recycling lithium carbonate from the lithium iron phosphate waste material is provided. The method provided by the invention comprises the following steps of: roasting the lithium iron phosphate waste material at 500-800 DEG C for 1-4 hours; adding sulfur into the roasted waste material and leaching, and filtering so as to obtain a mixed solution of lithium phosphate, iron phosphate and ferric sulfate; heating the mixed solution to 80-100 DEG C, and adjusting the pH value to 2-2.5, reacting for 1-4 hours, filtering, washing, and drying to obtain iron phosphate; adjusting the pH value of a filtrate obtained by filtering to be 6-7, adding calcium chloride and dephosphorizing, and filtering; and adjusting the pH value of the filtrate obtained by filtering to be 10-12 by sodium carbonate, reacting for 0.5-2 hours, filtering, washing, and drying so as to obtain battery grade lithium carbonate.

The invention relates to a water system high-voltage mixed ion secondary battery. A positive pole material of the battery is a high-voltage battery positive pole material, namely zinc-lithium ferric manganese phosphate (LiFe1-xMnxPO4), the element zinc serves as the majority of a negative pole material, and electrolyte is a liquid-state or gel-state material which is formed by lithium bis(trifluoromethane sulfonimide) (LiTFSI) and soluble zinc salt as solute and water as solvent and has ionic conductivity. The battery is based on the energy storage mechanisms of a dissolution-out/deposition reaction of zinc ions (Zn2+) on a negative pole and a reversible embedding/ejection reaction of the zinc ions (Zn2+) on a positive pole, meanwhile, through the water-in-salt electrolyte formed by high-concentration LiTFSI, the electrochemical water decomposition process is inhibited, a potential window of the water system electrolyte is remarkably broadened, the zinc-lithium mixed ion secondary battery has the advantages of being high in capacity, long in cycling life, safe, environmentally friendly, low in cost and the like, and the battery can be applied to the fields such as consumer electronic equipment, electromobiles and large-scale energy storage.

The invention discloses a method for preparing wafer-like ferric phosphate, which comprises the following steps of: adding deionized water of which the pH value is pre-adjusted to 1 by nitric acid into a reactor with stirring, then adding an iron source into the reactor, completely dissolving the iron source with the stirring, then adding a certain amount of phosphoric acid or phosphate, urea and surfactant into the reactor respectively, adjusting the pH value of reaction solution by using the nitric acid or sodium hydroxide, heating the solution in the reactor to be between 80 and 100 DEG C, performing reaction for 1.5 to 3 hours within the temperature range to obtain a white suspension, cooling and filtering the suspension, washing a filter cake by using the deionized water, and drying the filter cake for 3 to 6 hours in a baking oven at the temperature of between 102 and 120 DEG C to obtain ferric phosphate powder. The product has good whiteness, is of wafer shapes and has more uniform particle sizes; the average particle size is between 0.3 and 0.5 microns; and the tap density is more than or equal to 0.95g/cm3. The discharge capacity of lithium ferric phosphate, which is further synthesized by using the ferric phosphate prepared by the method as a raw material and is taken as an anode material of a lithium ion battery, can reach more than 140mAh/g under the condition of 0.5C. The method has the advantages of short reaction time, simple process, high product purity, and more regular morphology, and is easy to realize industrialization.

The invention belongs to the technical field of efficient development of ultralow-grade ore resources and comprehensive utilization of associated minerals, and in particular relates to a combined beneficiation method and a combined beneficiation system for comprehensive recovery of associated iron-phosphate minerals. The combined beneficiation method for the comprehensive recovery of the associated iron-phosphate minerals comprises the following steps: sequentially performing three-section and two-closed-loop crushing and screening flow on raw ores, and performing dry separation to obtain fine ores; performing two-section closed-loop ore-grinding flow on the fine ores, performing fine magnetic separation for three times, and concentrating by using a wash mill to separate iron ore concentrate and discharge tailings; performing one-time roughing, one-time scavenging and three-time concentrating on the tailings at the temperature of 10-15 DEG C to obtain phosphate ore concentrate by floatation. Compared with the prior art, the invention provides a comprehensive recovery scheme for magnetic iron ore resources and phosphate ore resources in ultralow-grade associated iron-phosphate minerals. According to the scheme, the separation cost is low, the efficiency is high, energy is saved, the space occupation is low, and the comprehensive recovery of the magnetic iron ores and the phosphate ores can be realized.

The invention discloses a method for preparing a porous spherical Li(1-x)MxFe(1-y)Ny(PO4)([3+(alpha-1)x+(beta-2) y]/3)/C material, comprising the specific steps of: dissolving a lithium-containing compound, an iron-containing compound, a phosphor-containing compound and a element-doped compound additive in a dispersing agent to form a sizing agent; dispersing a mixture of a pore-forming agent, a cladding agent and a stabilizer in a dispersing agent through ultrasound, then adding into the sizing agent and mixing to form a new sizing agent; carrying out a physical method or a chemical method on the new sizing agent to obtain a sizing agent with the primary particles in nano grade; carrying out spraying drying and granulating on the obtained sizing agent with the primary particles in nano scale to obtain a dry mixed material with secondary particles with spherical appearances; then carrying out a sintering process on the dry mixed material to obtain the product of the invention. The method has the advantages that besides that the primary particles reach the nano scale, the particle diameters are more uniform in distribution and more regular in appearance, an iron phosphate product synthesized from the material has the particle diameters with uniform distribution, and the material has favorable processability, good electric conductivity, excellent power multiplication performance and higher actual capacity.

The invention discloses a method for recovering lithium from lithium iron phosphate. The method disclosed by the invention comprises the following steps: dissolving waste lithium iron phosphate slag with sulfuric acid and ferric sulfate, leaching iron, lithium and phosphorus, adding an oxidizing agent, reacting iron and phosphate radicals to produce an iron phosphate precipitate and a small amountof ferric hydroxide, converting lithium into a water-soluble lithium sulfate solution, filtering to obtain the lithium sulfate solution, adding sodium carbonate into the lithium sulfate solution to prepare a lithium carbonate product, and adding sodium phosphate or phosphoric acid to prepare lithium phosphate; dissolving the lithium phosphate with ferric sulfate again to obtain the lithium sulfate solution and a compound taking iron phosphate as a principle component, returning the lithium sulfate solution to the system to prepare lithium carbonate, and calcining the iron phosphate slag to remove organic matters and carbon in the slag; and slurrying to prepare cell grade iron phosphate. According to the method for recovering lithium from lithium iron phosphate disclosed by the invention,the lithium is totally converted into the product lithium carbonate in the method, the process flow is short, the cost is low, the lithium recovery rate is 97%, the metal lithium in the lithium iron phosphate can be effectively recovered, and all the slag is converted into the cell grade iron phosphate.

The invention relates to a method for preparing uniformly dispersed spherical lithium iron phosphate-an anode material for a lithium ion battery, and belongs to the field of green energy materials. The method comprises the following steps: firstly, preparing a spherical iron phosphate precursor through liquid-phase homogeneous precipitation; secondly, performing predecomposition on the spherical iron phosphate precursor at a temperature of between 350 and 450 DEG C for 2 to 8 hours under the protection of inert gas; and thirdly, performing reaction at the temperature of between 550 and 800 DEG C for 2 to 24 hours to obtain the uniformly dispersed spherical lithium iron phosphate. The particle diameter of the product is between 100 and 200 nanometers, the tap density is between 1.6 and 2.0 g/cm, and the specific capacity of initial discharge at the room temperature reaches 140 to 160 mAh/g. The method utilizes a liquid-phase spheroidization process to prepare the uniformly dispersed spherical lithium iron phosphate, has simple process, and is easy to realize industrialized production.

The present invention belongs to energy material, and in particular relates to a method of using high-activity disordered iron phosphate to prepare ferrous phosphate lithium/carbon composite material. A ferrous iron source is mixed with phosphorus source solution according to stoichiometric ratio, has hydrogen peroxide added in, has pH value controlled and is stirred so as to prepare high-activity disordered iron phosphate. iron phosphate, a lithium source and a carbon source are mixed pro rata, ball-milled uniformly, spray-dried and treated via high temperature under protective atmosphere, so as to obtain high specific capacity ferrous phosphate lithium/carbon composite material of which the average particle diameter is 200-500nm, 0.25C rate specific discharge capacity reaches 145-150mAh/g, 1C rate specific discharge capacity reaches 130-140mAh/g, and 5C rate specific discharge capacity reaches 105-110mAh/g. The method is low in cost and simple in process. Prepared material is good in electrochemical performance and especially excellent in rate performance, which is applicable to battery anode material of electric vehicles and other large-scale mobile devices.

The embodiment of the invention discloses a method for preparing hollow polyaniline microspheres, comprising the following steps: mixing aniline and an oxidant at the molar ratio of 1:(1.5-15) in a solvent for reaction, wherein the aniline can be potassium ferricyanide, sodium ferricyanide, iron phosphate or copper sulfate; and drying the products of reaction to obtain the hollow polyaniline microspheres. In the process of preparing the hollow polyaniline microspheres, spherical micelles are formed by the aniline in the solvent, and the cores of the spherical micelles are filled with aniline droplets. Because the oxidant adopted by the method has low oxidation-reduction potential, the oxidant can not generate acidic materials in the aniline polymerization process, the spherical micelle structure can be prevented from being changed to be in linear or sheet shape, and the hollow polyaniline microspheres can be finally obtained. The method does not require a dopant, is simple, ensures lower cost and can be used for preparing the hollow polyaniline microspheres.