Effect of Mg and Co co-doping on electrochemical properties of LiFePO4

LiFePO4 co-doped with Mg2+ and Co4+ ions was synthesized by a solid state reaction method. The structure and electrochemical properties of the prepared LiFe0.99Mg0.005Co0.005PO4 were investigated by X-ray diffraction (XRD), galvanostatic charge-discharge experiment and cyclic voltammograms (CV). Specific discharge capacity of LiFePO4 co-doped with Mg and Co ions reach 147.2 mA.h/g at 0.1C and 133.3 mA.h/g at 1C. The results of CV show that the reversibility of lithium extraction/insertion in LiFePO4 can be promoted by (Mg2+, Co4+) multiple-ion doping.