Effect of Carbon Coating and Magnesium Doping on Electrochemical Properties of LiFePO4 for Lithium Ion Batteries

Abstract

Li1-2xMgxFePO4 (x = 0, 0.03) composites were synthesized by a mechanical activation process. The effect of ball milling time, magnesium doping, and carbon coating on their properties was investigated. Carbon coating on the surface of the particles reduces the difference in the surface area between the undoped and the doped LiFePO4. Magnesium doping invigorates the electronic properties of the carbon coated LiFePO4 as reduced interfacial resistance and higher capacity were obtained after the magnesium doping. The composite with Mg doping and 5 wt.% carbon coating showed a high discharge capacity of 163.1 mAh/g with high cycle stability at 1 C-rate.