A novel environment-friendly synthesis of high purity micron iron phosphate and its application as a precursor of lithium iron phosphate

Abstract

This essay studies a novel environment-friendly synthesis method for the high purity micron iron phosphate. Compared with traditional synthesis method, this new method can greatly reduce the amount of industrial sewage, hence it is an environment-friendly production technology which can effectively improve the products’ purity, structure stability and morphological consistency. This new method includes two-step reactions: first, phosphoric acid, iron powder and hydrogen peroxide are used as raw materials to obtain iron phosphate dihydrate intermediate, which is then calcined at high temperature to obtain anhydrous iron phosphate. The results show that the iron phosphate prepared for this new method is a hexagonal system-structured iron orthophosphate with high purity and without any impurities, exhibiting a regular and primary spherical particle morphology, at the average size of 3.096μm in particle and the specific surface area reaching 39.1765 m2 g−1. With these excellent characteristics, it has better application potentials in the field of electrode material preparation. The electrochemical performance of lithium iron phosphate anode materials synthesized with it as the precursor is superior to those synthesized with the iron phosphate prepared by the traditional method as precursor. The first specific capacity of discharge at 0.5C and 10C can be as high as 154.3989 or 102.9326 mAh g−1, increasing by 2.74% and 8.03%, respectively.