Effect of rare earth elements doping on structure and electrochemical properties of LiNi1/3Co1/3Mn1/3O2 for lithium-ion battery

A series of cathode materials for lithium-ion batteries with the formula Li[Ni1/3Co1/3Mn1/3](1-x)RexO2(Re=La, Ce, Pr) have been synthesized using a sol-gel method with citric acid as chelating agent. The effect of rare earth elements doping on the structure and electrochemical properties of LiNi1/3Co1/3Mn1/3O2 were investigated by XRD, charge-discharge experiments and EIS. The results show that the discharge capacity and cycling performance of LiNi1/3Co1/3Mn1/3O2 have been greatly improved with rare earth elements doping. Characterization of EIS reveals that the increase of charge-transfer resistance during cycling has been suppressed successfully by rare earth elements doping. (C) 2007 Elsevier B.V. All rights reserved.