Preparation method of ferric phosphate with high iron/ phosphorus ratio

Abstract

The invention discloses a preparation method of ferric phosphate with a high iron / phosphorus ratio. The preparation method comprises following steps: step one, preparing a ferrous salt solution, adding a phosphoric acid solution and PEG into the ferrous salt solution to obtain a reaction base solution, filling the reaction base solution into a reactor, and stirring the reaction base solution; step two, preparing a phosphate-hydrogen peroxide mixed solution, adding the phosphate-hydrogen peroxide mixed solution into the reactor with the reaction base solution, after ferrous ions are completelyconverted into ferric ions, raising the temperature until the temperature reaches 88 to 92 DEG C, maintaining the temperature until all reaction materials turn white, starting timing, and keeping onreactions at a constant temperature; and step three, after reactions, washing the slurry until the conductivity of the slurry is lower than 150 [mu]S / cm, and burning the slurry in a furnace to obtainthe ferric phosphate with a high iron / phosphorus ratio. Compared with the prior art, the iron / phosphorus ratio of prepared ferric phosphate can reach 0.98-1.00; and moreover, the content of impurities such as sulfur, manganese, and the like, is low.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to a method for preparing iron phosphate with a high iron-to-phosphorus ratio. Background technique [0002] With the depletion of petrochemical energy and the increasing greenhouse effect, people are constantly looking for environmentally friendly new energy sources that can avoid environmental pollution. Lithium-ion batteries, as the power source of electric vehicles, have attracted extensive attention from researchers. At present, all countries have placed the battery industry in an important position in the national development strategy. Lithium iron phosphate has been widely used in energy storage equipment, electric tools, electric buses, electric automotive and other fields. [0003] With the country's popularization and application of new energy vehicles and the development of energy storage batteries, the demand for lithium iron phosphate will also increase sharp...

AI Technical Summary

Problems solved by technology

The iron-to-phosphorus ratio of iron phosphate prepared in the prior art is usually 0.96-0.97, and some methods can reach about 0.98, but the operation steps are extremely complicated, resulting in high production costs, which is not conducive to industrial production

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