Combustion synthesis of nanocrystalline LiNiYCo1−2YMn1+YO4 spinels for 5 V cathode materials: Characterization and electrochemical properties

Nanosized double substituted LiNiYCo1−2YMn1+YO4 (Y = 0.05, 0.1, 0.25 and 0.45) spinels have been synthesized by a single-step combustion-aided procedure, which use sucrose as fuel. The as prepared samples contained some amorphous organic impurities that were removed after a short heating at 400 °C. The samples have been characterized by X-ray diffraction, thermal analysis and transmission electron microscopy. Lattice parameter of the spinels increased with nickel content, and decreased from 400 to 600 °C, at which temperature stoichiometric spinels with particle size of ≈20 nm were obtained. The electrochemical properties of the 600 °C-treated samples in the 5 V region have been studied. The sample with composition LiNi0.45Co0.1Mn1.45O4 has shown the best electrochemical performance, with redox potential of 4.6 V, capacity of 129.6 mAh g−1, cyclability of 99.6% per cycle, and retained the capacity up to 1C rate.