13 results about "Iron oxalate" patented technology

The invention discloses a manganese iron oxalate precursor, a lithium manganese iron phosphate material and a preparation method and application of the manganese iron oxalate precursor and the lithium manganese iron phosphate material, and belongs to the technical field of battery materials. The lithium manganese iron phosphate material core layer is prepared by taking the oxalate manganese iron precursor with a specific particle size range, particle size distribution uniformity and a specific structure as a raw material, and meanwhile, the shell layer comprising the ionic conductive agent and carbon is introduced outside the core layer, so that the comprehensive performance of the lithium manganese iron phosphate material can be effectively improved; and thus, the capacity, the cycle performance and the first charge-discharge efficiency of the prepared corresponding secondary battery are improved.

The utility model particularly relates to three-axis linkage synthesis mixing equipment, a mixing reaction method and a method for preparing ferric oxalate. The three-axis linkage synthesis mixing equipment comprises a motor and a gear box, a volute is arranged at the top of the outer barrel, and an air outlet is formed in one side of the volute and used for exhausting air; the three rotating shafts are arranged in the outer cylinder body, each rotating shaft is provided with an inner cylinder body, a plurality of vertically arranged gas-liquid separation plates are uniformly arranged on the upper part of each inner cylinder body along the peripheral side, and a plurality of layers of blades which are parallel to one another and are obliquely arranged are arranged on the lower part of each inner cylinder body along the peripheral side; the bottom of the volute is provided with an opening matched with the inner cylinder with the gas-liquid separation plate in size; the inner cylinders on the three rotating shafts are mutually enclosed to form an inner duct, and the rotating shafts are synchronously driven by a motor to rotate through a gearbox; a plurality of annular separation discs are arranged on the inner wall of the outer cylinder body; and an air inlet is further formed in the peripheral side of the outer cylinder body. The utility model has the advantages that the contact area and the contact time of the solvent and the air are fully increased and prolonged in a weightless state.

To provide a method for preparing an in situ metal doped manganese iron oxalate precursor.SOLUTION: Iron source, manganese source, doped metal elements (Mg, Zn, etc.) are weighed according to a stoichiometric ratio, and deionized water is added to the weighed metal to ultrasonically dissolve the weighed metal to obtain a mixed metal solution. The mixed metal solution is added to a prepared oxalic acid solution and subsequently a certain concentration of complexing agent is added to the solution to perform co-precipitation reaction under the protection of inert gas. A resultant suspension of metal doped manganese iron oxalate is recovered and then filtered, washed and dried to obtain a powder of manganese iron oxalate precursor.EFFECT: By using the manganese iron oxalate precursor as the iron and manganese sources, this can effectively avoid the problem of uneven mixing due to the iron and manganese sources. Moreover, lithium manganese iron phosphate synthesized from the manganese iron oxalate precursor after metal doping can significantly improve the electronic conductivity, thereby enhancing the electrochemical properties of lithium manganese iron phosphate.SELECTED DRAWING: Figure 1

Provided are a composite carbon source-coated lithium manganese iron phosphate cathode material and a preparation method and use thereof.SOLUTION: (1) subjecting a two metal mixed solution containing a manganese source and an iron source to a co-precipitation reaction with an oxalic acid solution, followed by filtration, washing and drying to obtain a manganese iron oxalate precursor, and (2) mixing the manganese iron oxalate precursor with a lithium source and a carbon source, followed by sand grinding, spray drying, sintering and grinding to obtain the lithium manganese iron phosphate cathode material. The method has the advantages of simple preparation process, easy industrial mass production, good economic benefit and low preparation cost, and can effectively improve the charge and discharge specific capacity of the lithium manganese iron phosphate cathode material, and the composite carbon source-coated lithium manganese iron phosphate cathode material solves the problems of poor electron conductivity, low lithium ion diffusion rate and the like.SELECTED DRAWING: Figure 3

The invention discloses a thin-layer iron monatomic catalyst for efficiently degrading intracellular resistance genes and application, and relates to the technical field of material engineering and environmental engineering. The preparation method comprises the following steps: firstly, carrying out graded assembly on ferric oxalate, cyanuric acid and melamine according to a hydrogen bond acting force sequence to construct a supramolecular solid; by utilizing the low-boiling-point characteristic of a small-molecular alcohol compound, interlayer intercalation and stripping are realized by adopting a condensation reflux device, and a supramolecular precursor is obtained; and then pyrolyzing in argon to prepare the iron monatomic catalyst with controllable layer number. The iron monatomic catalyst with high loading capacity and a thin-layer structure is constructed through a strategy of oxalic acid bridging coordination and intercalation stripping, the exposure rate of active sites and the accessibility of a reaction substrate are essentially improved through the design, and a new material and a new technical scheme are provided for efficient and stable removal of intracellular resistance genes.

The application provides a manganese iron oxalate precursor material and a preparation method thereof, a manganese iron lithium phosphate positive electrode material, a positive electrode sheet and a secondary battery, and relates to the technical field of secondary batteries. x Fe (1‑x) C2O4,0

The invention relates to a porous ferroferric oxide / nitrogen-doped carbon composite material as well as a preparation method and application of the porous ferroferric oxide / nitrogen-doped carbon composite material, and belongs to the technical field of secondary battery materials. On one hand, nitrogen-doped carbon formed by pyrolysis of polyacrylonitrile can effectively improve the conductivity of the material and provide multiple active sites, and on the other hand, the synergistic effect of the two materials can effectively improve the electrochemical performance of the material as a lithium ion battery negative electrode material; in addition, the porous structure can provide a convenient lithium ion transmission channel and buffer volume expansion; the method is simple in preparation process, mild and controllable in reaction condition, high in product yield, low in cost and convenient to popularize and apply; the prepared porous ferroferric oxide / nitrogen-doped carbon composite material (Fe3O4 / NC) is excellent in electrochemical performance and has a wide application prospect.

This application provides a continuous reaction system, a manganese iron oxalate precursor, lithium manganese iron phosphate, a preparation method, and a secondary battery. The preparation method of the manganese iron oxalate precursor provided in this application is a continuous preparation method, which can improve production efficiency, simplify the production process, and obtain a manganese iron oxalate precursor with small particle size, narrow particle size distribution, uniform elemental distribution, high crystallinity, regular morphology, and high batch stability and consistency.

The invention provides an oxalate ferromanganese precursor material and a preparation method thereof, a lithium iron manganese phosphate positive electrode material, a positive electrode plate and a secondary battery, and relates to the technical field of secondary batteries. The chemical formula of the oxalate ferromanganese precursor material is MnxFe (1-x) C2O4, 0lt; xlt; 1; primary particles of the oxalate ferromanganese precursor material are of a sheet structure, the length of the primary particles ranges from 1000 nm to 1500 nm, the width of the primary particles ranges from 400 nm to 870 nm, and the thickness of the primary particles ranges from 300 nm to 500 nm. By controlling the composition of the manganese iron oxalate precursor material and the morphology and size of primary particles, the electrochemical performance of the lithium manganese iron phosphate positive electrode material prepared from the manganese iron oxalate precursor material in the aspects of charge-discharge specific capacity and first coulombic efficiency can be improved.

The application relates to the technical field of battery material preparation, in particular to a method for preparing iron phosphate, iron phosphate and application. The method comprises the steps of adding a crystal form inhibitor into a crude iron phosphate product, aging, and calcining; the crystal form inhibitor comprises a phosphoric acid type crystal form inhibitor and an iron type crystal form inhibitor; the phosphoric acid type crystal form inhibitor comprises at least one of monoammonium phosphate, diammonium phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate and phosphoric acid; and the iron type crystal form inhibitor comprises at least one of iron hydroxide, iron hydroxyphosphate, iron sulfate and iron oxalate. The prepared iron phosphate has few by-products in the aging stage, high iron-phosphorus ratio, good capacity and rate performance, and long cycle life.

The application provides a preparation method of carbon composite divalent silicon material, comprising the following steps: grinding silicon-containing biomass into solid powder, mixing the solid powder with a metal oxalate mixture, calcining under an inert atmosphere, performing a carbothermic reduction reaction, and removing impurities to obtain the carbon composite divalent silicon material; the metal oxalate mixture is composed of two metal oxalates, namely a first metal oxalate and a second metal oxalate; the first metal oxalate is selected from one of tin oxalate or manganese oxalate; the second metal oxalate is selected from one of manganese oxalate, iron oxalate or zinc oxalate; the first metal oxalate is different from the second metal oxalate; and the molar ratio of the first metal oxalate to the second metal oxalate is 10:1-3. The molten metal ball formed by the metal oxalate mixture during high-temperature calcination catalyzes the reduction of tetravalent silicon in the silicon-containing biomass into divalent silicon, the catalytic efficiency is high, and the energy consumption and production cost of the reaction are reduced.

This invention provides a method for preparing lithium manganese iron phosphate cathode material with a gradient core-shell structure. Magnesium-doped manganese iron oxalate is synthesized via liquid-phase co-precipitation. Subsequently, the manganese iron oxalate is ball-milled and mixed uniformly with lithium dihydrogen phosphate and a carbon source, followed by drying and sintering to obtain lithium manganese iron phosphate. The lithium manganese iron phosphate is then ultrasonically dispersed in a prepared precursor solution and transferred to a reaction vessel for reaction. Finally, it is ground, dried, and calcined at high temperature with a sucrose solution to obtain lithium manganese iron phosphate with a core-shell structure. This method effectively solves the problems of poor conductivity, Jahn-Teller distortion caused by Mn³⁺, lattice stress accumulation, and manganese dissolution in existing lithium manganese iron phosphate materials, which lead to a decrease in cycle life and rate performance.

The invention provides a method for recycling waste lithium manganese iron phosphate, which comprises the following steps of: performing solid-liquid separation on a leaching agent and waste lithium manganese iron phosphate to obtain a lithium phosphorus resource and a manganese iron resource, performing copper removal, acid dissolution carbon removal and distillation aluminum removal on the manganese iron resource to obtain a high-purity manganese iron oxalate crystal, performing copper removal and aluminum removal on the lithium phosphorus resource, and concentrating and crystallizing to obtain the waste lithium manganese iron phosphate. The high-purity lithium dihydrogen phosphate is obtained. The product prepared by the method is high in purity and good in crystallinity, can provide a high-quality raw material for regenerating the lithium manganese iron phosphate, and solves the industrial problem that aluminum impurities in the regenerated product exceed the standard due to phosphorus, iron and aluminum eutectic when the waste lithium manganese iron phosphate is regenerated at present; and the whole process flow has the advantages of low recovery cost, high resource utilization rate, simplicity in operation, greenness, environmental protection and the like, and has a good industrial application prospect.