High rate performance of LiFePO₄ cathode materials co-doped with C and Ti⁴⁺ by microwave synthesis

Abstract

Nanostructured LiFePO₄ powder with a narrow particle size (ca. 100 nm) for high rate lithium-ion battery cathode application was obtained by microwave heating and using citric acid as carbon source. The microstructures and morphologies of the synthesized materials were investigated by X-ray diffraction and scanning electron microscope while the electrochemical performances were evaluated by galvanostatic charge-discharge. The carbon coating and Ti⁴⁺ could improve the conductivity both between the LiFePO₄ particles and the intrinsic electronic conductivity. The LiFePO₄ doped with 5% C and 1% Ti⁴⁺ resulted in a specific capacity of 114·95 mAh·g⁻¹ and 102·4 mAh·g⁻¹ at discharge rates of 0·3C and 1C, respectively, and the cycle performance is very good.