Wafer-like ferric phosphate, preparation method and application thereof

Abstract

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.

Description

Technical field: [0001] The invention relates to an inorganic salt and a preparation method thereof, in particular to a preparation method of disc-shaped iron phosphate powder, which can be used to prepare lithium iron phosphate, a cathode material of a lithium ion battery. Background technique: [0002] Ferric phosphate is a widely used chemical raw material. It can be used as a food thickener and iron supplement, and can also be used in pigments, catalysts for organic synthesis, and glazes for ceramic and metal glazes. In recent years, iron phosphate has been used as a high-quality raw material for the production of lithium iron phosphate, a cathode material for lithium-ion batteries, and has important application value. In Chinese patent (publication number CN1255888, a preparation method of lithium iron phosphate, a positive electrode material for lithium ion batteries), Chinese patent (publication number CN100389062, a method of preparing carbon-coated lithium iron phos...

AI Technical Summary

Problems solved by technology

The proportion of iron phosphate produced by these traditional methods is difficult to control, the impurities are high, the particle shape is irregular, and the size is not uniform

Lithium iron phosphate synthesized from iron phosphate prepared by these traditional methods has two disadvantages. One is low electrical conductivity, resulting in poor high-rate charge and discharge performance; the other is low tap density, resulting in low volume specific capacity.

Images