An Improved Method to Prepare FePO4 by Introduction of Na3PO4 and Its Usage for Fabricating LiFePO4

Abstract

A LiFePO4/C composite was synthesized by a simple solid-state reaction method using glucose as reductive agent and carbon source and FePO4 as precursor, which was prepared by introduction of Na3PO4 as phosphorus source and pH regulator in order to pursue lower cost and environmental protection. The structure and morphology of FePO4 and LiFePO4/C were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Furthermore, electrochemical performance of LiFePO4/C was investigated by galvanostatic charge–discharge tests and cyclicvoltammogram (CV). The results indicate that FePO4 obtained has a small particle size and uniform particle distribution, which is demonstrated to be applicable as the iron source to synthesize LiFePO4/C. Prepared LiFePO4/C shows an excellent rate capability and cycle performance. At rates of 0.1 C, 0.2 C, 1 C and 2 C, the initial discharge capacities of 161, 158, 145 and 120 mAh/g were achieved, respectively and the discharge capacity is 154, 153, 140 and 116 mAh/g after 400 cycles. The employed method of preparing FePO4 by introduction of Na3PO4 has advantages such as low cost, safe raw material, environmental benign and recyclable products, which is suitable for industrial production.