Combustion synthesis and electrochemical performance of Li [Li0.2Mn0.54Ni0.13Co0.13]O2 with improved rate capability

Li-rich layered oxide Li[Li0.2Mn0.54Ni0.13Co0.13]O-2 is synthesized by combustion reaction using alcohol as both solvent and fuel. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that the oxide synthesized at 800 degrees C exhibits perfect crystallinity and lattice ordering, and has particle sizes of 50-150 nm. The layered oxide delivers an initial discharge capacity of 290.1 mAh g(-1) at a current density of 20 mA g(-1) after activation, and exhibits improved rate capability with high discharge capacities of 238.6 and 165.0 mAh g(-1) at current densities of 200 and 2000 mA g(-1) in the voltage range of 2.0-4.8 V, respectively. Low Li-ion diffusion coefficient of 1.07 x 10(-14)-1.01 x 10(-16) cm(2) s(-1) is calculated by galvanostatic intermittent titration technique (GITT) during the initial discharge process, indicating that the improved rate capability is mainly attributed to the small particle sizes of the Li-rich oxide. (C) 2012 Elsevier B.V. All rights reserved.