Electrochemical properties of nanometer-sized 0.6Li ₂MnO ₃·0.4LiNi _0.5Mn _0.5O ₂ composite powders prepared by flame spray pyrolysis

Nanometer-sized 0.6Li ₂MnO ₃·0.4LiNi _0.5Mn _0.5O ₂ composite cathode powders are prepared directly by high-temperature flame spray pyrolysis. The precursor powders and the powders post-treated at 800 °C exhibit mixed-layered crystal structures comprising layered Li ₂MnO ₃ and layered LiNi _0.5Mn _0.5O ₂ phases. The discharge capacity of the precursor powders decreased from 193 mAh g ^-1 to 96 mAh g ^-1 by the 9th cycle, corresponding to a capacity retention of 49.7%. Post-treatment at 800 °C increases the capacity retention of the post-treated composite powders to 94.6% after 50 cycles, corresponding to a decrease in the discharge capacity from 225 to 213 mAh g ^-1. The post-treated composite powders that contain a high amount of the Li ₂MnO ₃ phase have a high initial discharge capacity and good cyclability.