Preparation method of manganese iron phosphate and product

Abstract

The invention discloses a preparation method of manganese iron phosphate and a product. The method comprises the following steps: selecting a manganese source and an iron source to be dissolved in a proper amount of water respectively, respectively adding a proper amount of a phosphorus source, then transferring two mixed solutions into a reaction kettle, and adjusting the pH of the solution to be smaller than 2 at that time; adding an oxidant and a dispersant, raising the temperature to be 50-150 DEG C, and reacting for 2-24 h; washing, filtering and drying a manganese iron phosphate slurry to obtain a final product MnXFe1-XPO4.yH2O, wherein y is 0 or another numerical value. The manganese iron phosphate finished product MnXFe1-XPO4.yH2O (with or without crystal water) obtained by the preparation method is high in purity, the valence states of manganese and iron are positively trivalent, the contents of Mn and Fe are greater than 31%, the content of P is 18-19%, the content of S is smaller than 0.4%, the particle size distribution is uniform, the average particle size is 2.50 microns, the product is monoclinic, and primary particles are in the forms of sheets.

Description

technical field [0001] The invention belongs to the technical field of preparation of positive electrode materials for lithium ion batteries, and in particular relates to a method and a product for preparing manganese phosphate by an oxidation-precipitation process in a liquid phase system. Background technique [0002] The lithium iron manganese phosphate battery material has been widely concerned and researched at present. It has the same specific capacity (170mAh / g) as lithium iron phosphate, but has a higher discharge voltage (3.9-4.0V, vs. Li), and the energy density is in Lithium iron phosphate has increased by 20%, so lithium iron manganese phosphate replaces lithium iron phosphate and becomes the preferred positive electrode material for new power and energy storage lithium batteries. Ferromanganese phosphate is used as the raw material for the production of cathode materials for lithium iron manganese phosphate batteries, and its quality is crucial. [0003] Chines...

AI Technical Summary

Problems solved by technology

The problem is that the reaction height of this method is high, and the requirements for equipment are also high, which is not conducive to the large-scale production of the factory; and the finished product of iron manganese phosphate prepared by this method has low purity and wide particle size distribution, which cannot meet the use requirements of lithium batteries.

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