Influence of synthesis parameters on the properties of FePO4·2H2O used for the precursor of LiFePO4 cathode material

A series of FePO4·2H2O particles were prepared via rapid precipitation method for process parameters optimizing. The influences of surfactant type, its amount, aging time, and ultrasound time were systematically investigated. The obtained FePO4·2H2O particles were characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetric-differential scanning calorimetry (TG-DSC), Fourier transform infrared spectroscopy (FTIR), and iron–phosphorus ratio (n(Fe):n(P)). Results show that surfactant, aging time, and ultrasound time have significant effects on the agglomeration and morphology of FePO4·2H2O particles. The best conditions for preparing FePO4·2H2O particles with good dispersity are surfactant CTAB with adding 1.5% of the iron powder mass, 4 h aging, and 60 min of ultrasonic treatment, respectively. This work suggests that the optimized rapid precipitation method is a promising method to synthesize FePO4·2H2O used in industrialization.