Effect of thermal annealing on the structure of LiCoO2 powders prepared by co-precipitation method

Highlights: • Structure of LiCoO2 powder was studied by Synchrotron XRD and XAS techniques. • Formation of HT-LiCoO2 phase was observed at annealing temperature of 300 °C. • Washing process affects surface chemical composition of LiCoO2 powder. Lithium cobalt oxide (LiCoO₂) powder was prepared by co-precipitation method and annealed at different temperatures of between 300 and 700 °C. The effect of annealing temperature and effect washing process with deionized water on the crystal structures of the prepared LiCoO₂ powders were thoroughly studied by Synchrotron powder X-Ray Diffraction (Syn-XRD), X-ray Absorption Spectroscopy (XAS), Dispersive Raman Microscopy (Raman) techniques. The change in chemical composition as a function of annealing temperature was also investigated by X-ray Photoelectron Spectroscopy (XPS) technique. The crystal structural results identified the phase evolution of the prepared LiCoO₂ powders upon heat treatment. The formation of HT-LiCoO₂ phase was observed at annealing temperature as low as 300 °C.