Synthesis and characterization of Zn-doped LiCo0.3Ni0.4(xMn0.3ZnxO2 cathode materials for lithium-ion batteries

Zn-doped LiCo0.3Ni0.4-xMn0.3ZnxO2 cathode materials were synthesized via co-precipitation method. The structure, electrochemical performance and thermal stability were characterized by X-ray diffraction (XRD), charge/discharge cycling, cyclic voltammograms (CV), electrochemical impedance spectroscopies (EIS) and differential scanning calorimetry (DSC). LiCo0.3Ni0.4-xMn0.3ZnxO2 had stable layered structure with a-NaFeO2 type with x up to 0.05. The compounds of x = 0.02 showed the best discharge capacity and cycle performance which was related to the most stable structure and Zn-doping prevented structural transformations during the topotactic reactions. Meanwhile, Zn-doping improved the high rate discharge capability and thermal stability. (C) 2008 Elsevier B.V. All rights reserved.