Synthesis, Characterization, and Electrochemical Performance of Ce-Doped Ordered Macroporous Li3V2(PO4)3/C Cathode Materials for Lithium Ion Batteries

A series of Ce3+-doped ordered macroporous Li3V2-xCex(PO4)(3)/C (x = 0, 0.01, 0.03, 0.05) samples have been fabricated via a colloidal crystal template method. The X-ray powder diffraction and scanning electron microscopy analysis demonstrate that the Ce element doping does not affect the original monoclinic structure and macroporous morphology of the pristine Li3V2(PO4)(3)/C sample. Electrochemical measurement results prove that the Li3V(1.97)Ce(0.03)(PO4)(3)/C sample presents the best electrochemical performance as the cathode material for lithium ion batteries among the as-prepared samples in the potential ranges of both 3-4.3 V and 3-4.8 V. The substitution of V3+ with an appropriate amount of Ce3+ increases the Li+ diffusion coefficient based on the electrochemical impedance spectroscopy results, which is mainly responsible for the excellent electrochemical performance.