Synthesis and characterization of Li1.05Co1/3Ni1/3Mn1/3O1.95X0.05 (X = Cl, Br) cathode materials for lithium-ion battery

In order to improve the thermal stability and dynamic performance of LiCo1/3Ni1/3Mn1/3O2 materials, Cl-doped and Br-doped materials were synthesized via the co-precipitation method. The morphology, structure, electrochemical performance and thermal stability were characterized by environment scanning electron microscopy (ESEM), X-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS), charge discharge cycling and differential scanning calorimetry (DSC). Results show that all materials had a stable layered structure with alpha-NaFeO2 and that Cl-doping slightly increased the size of grains. Both Cl-doping and Br-doping improved the high rate of discharge capacity, cycle-life performance and thermal stability, but Cl-doping was better than Br-doping in improving the material structure stability, dynamic performance and thermal stability. (C) 2013 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.