Electrochemical properties of nanosized Li₂MnO₃-Li(Ni_1/3Co_{1/3M n1/3})O₂ composite cathode powders prepared by spray pyrolysis

Nanosized 0.6Li₂MnO₃-0.4Li(Ni_1/3Mn_1/3C o_1/3)O₂ composite powders are prepared by spray pyrolysis at high post-treatment temperatures. The optimum concentrations of citric acid and ethylene glycol, selected as the appropriate organic additives to obtain the composite nanopowders, are 0.2 M each. The spherical precursor powders of large size, with hollow and porous structures, are converted into composite nanopowders. Transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and the cycling properties of the powders indicate that the optimum post-treatment temperature for obtaining composite cathode nanopowders is 900 °C. The mean size of the composite powders post-treated at 900 °C is 136 nm. The composite cathode powders post-treated at 900 °C have high initial charge/discharge capacities of 350 and 291 mAh g^-1. The discharge capacity of the composite cathode powder post-treated at 900 °C decreases from 291 to 269 mAh g_-1 by the 30th cycle, in which the capacity retention is 92.4%.