Solid state synthesis of ultrafine-LiCoO2 by enhanced thermal decomposition of carbonate precursors followed by double-calcining

Abstract Ultrafine LiCoO 2 powders with the layered rock-salt structure are successfully synthesized by enhanced thermal decomposition of carbonate precursors followed by double calcining. The mean size of the primary nanoparticles is about 500 nm with a narrow size distribution and is close to roundness with smooth surface. The LiCoO 2 powders are also characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). The lattice parameters of the synthesized LiCoO 2 powders are the same as those of the corresponding powders formed by conventional high temperature solid-state synthesis processing. The double-calcining heating method can improve the crystalline perfection and produce the high temperature phase. The mechanism of solid-state reaction is also discussed. The electrochemical properties of as-formed ultrafine-sized LiCoO 2 is examined and the maximum discharge capacities are 166.7 mAh/g, 160 mAh/g and 140 mAh/g at 0.2C, 0.5C and 1C, respectively. After 50 cycle performance, it is with a capacity retention of 88.84%, 88.10% and 72.90%, respectively.