A Simple and Low-cost Synthesis Strategy of LiFePO4 Nanoparticles as Cathode Materials for Lithium Ion Batteries

Abstract

In this work, pure LiFePO4 nanoparticles have been synthesized by a one-step facile hydrothermal stripping method. This particular method is environmentally friendly and cost-effective, allowing the recycling of solvents. The preparation procedure involves an aqueous solution and an organic phase. The organic phase is naphthenic acid loaded with ferrous ion. Since the extraction process can purify ferrous ions, inexpensive industrial-grade FeSO4·7H2O can be used as a raw material. The aqueous solution contains H3PO4 and LiOH. Pure LiFePO4 nanoparticles were synthesized by stripping ferrous ion from the organic phase and reacting precipitation in aqueous phase. The effect of various parameters, involving PH value, reactant concentration, amount of reducing agent, temperature and time on the properties of LiFePO4 was examined. By comparing the electrochemical properties of samples with different morphologies and particle sizes as cathode materials for lithium-ion batteries, the optimum LiFePO4 nanoparticles exhibited a high specific discharge capacity of 156.1 mAh g-1 at 0.1 C after 40 cycles, revealing their adequate cycling performance