Facile Synthesis and Electrochemical Performance of LiFePO4/C Composites Using Fe–P Waste Slag

A facile synthesis route has been developed to prepare LiFePO4/C composites by using Fe–P waste slag from the industrial production of yellow phosphorus. The processes included reclaiming Fe and P in the form of a ferroalloy, preheating the Fe–P with lithium salts, and complementary phosphorus source in air to produce a precursor, and calcining the precursor with glucose in Ar to obtain the products. The reaction process and electrochemical performance were investigated with various techniques. LiFePO4/C with 5.9 wt % carbon exhibits enhanced power capability, low polarization, high reaction activity and reversibility. The discharge capacities are 150, 147, 131, 124, 112, and 93 mAh/g at different current rates of 0.1, 0.2, 0.5, 1, 2, and 5 C, respectively. The recovery rate at 0.1 C is 98.9% after 130 cycles at the given rates. The results are comparable to that of the LiFePO4/C prepared using FePO4 or other Fe salts, which indicates the applicability of the novel simple way put forward in this work to convert industrial waste into energy materials for scaling up based on low cost.