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CN-118458722-B - Preparation method of doped ferromanganese phosphate precursor

CN118458722BCN 118458722 BCN118458722 BCN 118458722BCN-118458722-B

Abstract

The invention provides a preparation method of a doped ferromanganese phosphate precursor, and belongs to the field of preparation of positive electrode material precursors. The method comprises the steps of (1) mixing and grinding raw materials, namely mixing and wet-grinding a manganese source, an iron source, a doping agent, a phosphorus source and a dispersing agent, and (2) high-temperature aging and crystallizing the mixed slurry, namely obtaining a manganese iron phosphate suspension after high-temperature aging and crystallizing the ground slurry, and obtaining a manganese iron phosphate precursor after solid-liquid separation, washing and drying of the suspension. The preparation technical scheme of the doped ferromanganese phosphate precursor provided by the invention has the characteristics of simplicity, high efficiency, simple process control, easiness in industrialization and the like.

Inventors

  • WANG DONG
  • WANG JIE
  • ZHENG LEI
  • SUN NIAN
  • ZHAO WENHUI
  • WANG XIAOGANG
  • Jian Lishan
  • LIU AIPING

Assignees

  • 湖北兴发化工集团股份有限公司

Dates

Publication Date
20260508
Application Date
20240423

Claims (8)

  1. 1. The preparation method of the doped ferromanganese phosphate precursor is characterized by comprising the following steps of; (1) Mixing and wet grinding a manganese source, an iron source, a doping agent, a phosphorus source and a dispersing agent, wherein the dispersing agent is diisopropyl di (triethanolamine) titanate; (2) And (3) aging and crystallizing the ground slurry at high temperature to obtain a ferromanganese phosphate suspension, and performing solid-liquid separation, washing and drying on the suspension to obtain a ferromanganese phosphate precursor.
  2. 2. The method for preparing the ferric manganese phosphate precursor according to claim 1, wherein the manganese source is one or more of manganese metal, manganese monoxide, manganese dioxide, manganese sesquioxide, manganese tetraoxide, manganese carbonate, manganese oxalate and manganese dihydrogen phosphate, the iron source is one or more of iron powder, ferric oxide, ferric phosphate dihydrate and ferric phosphate, and the phosphorus source is one or more of phosphoric acid, ammonium dihydrogen phosphate and ammonium dihydrogen phosphate.
  3. 3. The method for preparing a manganese iron phosphate precursor according to claim 1, wherein when the raw materials contain a positive divalent manganese source and an iron source, an oxidant is added in the high-temperature aging crystallization step, and the oxidant is one or more selected from ammonium persulfate, hydrogen peroxide, nitric acid, sodium hypochlorite, oxygen, ozone and ammonium nitrate.
  4. 4. The method for preparing a precursor of ferromanganese phosphate according to claim 1, wherein the dopant is one or more of soluble titanium salt, soluble vanadium salt and soluble magnesium salt.
  5. 5. The method of preparing a manganese iron phosphate precursor according to claim 1, wherein the slurry has a solids content of 30-50%.
  6. 6. The method for preparing a manganese iron phosphate precursor according to claim 1, wherein the grinding method is one or both of ball milling and sand milling, and the particle size of the mixture after grinding is controlled to be 50 nm-800 nm with D 50 .
  7. 7. The method for preparing a precursor of ferromanganese phosphate according to claim 1, wherein the high temperature aging method is one or more selected from water bath heating, oil bath heating, electric heating, coil heating.
  8. 8. The method for preparing a manganese iron phosphate precursor according to claim 1, wherein the solid-liquid separation and washing method is one or more of suction filtration, centrifugation and pressure filtration, and the conductivity sigma of the filtrate after washing is controlled to be less than or equal to 500 mu s/cm.

Description

Preparation method of doped ferromanganese phosphate precursor Technical Field The invention belongs to the field of electrochemical energy storage of lithium ion battery anode materials, and particularly relates to a preparation method of a doped ferromanganese phosphate precursor material. Background The lithium iron manganese phosphate is hopeful to replace lithium iron phosphate due to the characteristics of good safety performance, high voltage platform, low cost (basically same as the lithium iron phosphate) and the like, becomes an ideal choice of a next-generation low-cost high-voltage novel anode material, and has huge practical application potential in long term when being applied to portable mobile energy storage, two-wheel electric vehicles and partial power vehicle types in a small area. The existing solid-phase method process has the characteristics of simple operation flow, large process window, easy industrialization and the like, but the existing solid-phase method process has the defects of uneven mixing, incapability of realizing atomic level fusion of ferromanganese, uneven carbon coating and the like due to various raw material types, and the prepared ferromanganese phosphate product often has the defects of large specific surface area, low compaction, poor processing performance and the like. On the other hand, the liquid phase method mainly comprises a sol-gel method, a hydrothermal-solvothermal method, coprecipitation and the like, wherein the sol-gel method and the hydrothermal-solvothermal method are generally used for laboratory-level preparation due to the defects of high raw material cost, high energy consumption, poor stability and the like, and the industrialization difficulty is high. The practical application of the coprecipitation method is commonly seen in preparing a lithium iron manganese phosphate precursor by coprecipitating divalent ferromanganese ions by using a solution of soluble carbonate (such as Chinese patent invention CNCN 104752719A) or oxalate (such as Chinese patent invention CN104752715A, CN 103887491A), and the method also has the technical difficulties of complicated process flow, harsh reaction conditions, more reaction technical condition limitations and the like. In summary, although the existing preparation technical routes of the lithium iron manganese phosphate are more, most of the existing preparation technical routes are still not mature enough, and the prepared lithium iron manganese phosphate positive electrode material also faces some problems to be solved urgently in practical application, such as problems of low conductivity and ion diffusion coefficient, low capacity, low compaction density, large specific surface area, high voltage platform attenuation caused by manganese dissolution and the like. Referring to the development history of the lithium iron phosphate industry, the lithium iron phosphate prepared by adding lithium carbonate into iron phosphate has the advantages of simple preparation process flow and obvious advantages in the aspects of cost, performance and production consistency. Therefore, the development of the precursor of the manganese iron phosphate for preparing the lithium manganese iron phosphate has the advantages of simpler process flow, uniform element mixing, high product capacity, good processability and the like. Therefore, developing a high-efficiency and simple preparation process flow of the ferric manganese phosphate precursor has very important significance for the preparation and development of the lithium manganese phosphate. Disclosure of Invention The invention aims to provide a simple and efficient preparation technology of a manganese iron phosphate precursor, and aims to simplify the production and preparation flow of manganese iron phosphate and improve the defects of poor dynamic behavior, low compaction, large specific surface area and the like of manganese iron lithium phosphate by the precursor technology. The preparation of the lithium iron manganese phosphate precursor is realized by the following technical scheme: A preparation method of a manganese iron phosphate precursor comprises the following steps of; (1) Mixing and wet grinding a manganese source, an iron source, a doping agent, a phosphorus source and a dispersing agent; (2) And (3) aging and crystallizing the ground slurry at high temperature to obtain a ferromanganese phosphate suspension, and performing solid-liquid separation, washing and drying on the suspension to obtain a ferromanganese phosphate precursor. The manganese source is one or more of metal manganese, manganese monoxide, manganese dioxide, manganese sesquioxide, manganous oxide, manganese carbonate, manganese oxalate and manganese dihydrogen phosphate, the iron source is one or more of iron powder, ferric oxide, ferric phosphate dihydrate and ferric phosphate, and the phosphorus source is one or more of phosphoric acid, ammonium dihydrogen phosphate and diammonium h