Simultaneous and Direct Fabrication of Lithium Cobalt Oxide Film and Powder Using Soft Solution Processing at 100°C

Lithium cobalt oxide film and powder as cathodes for lithium rechargeable batteries were simultaneously prepared in a single synthetic step using soft solution processing in 3 M LiOH solution at 100°C without any postsynthesis annealing. Their structure, chemical composition, and electrochemical activity were checked by X-ray diffraction pattern analysis, Raman spectroscopy, X-ray photoelectron spectroscopy, Co K-edge X-ray absorption near edge structure spectroscopy, and cyclic voltammetry. While layered LiCoO₂ in bulk form was prepared as a precipitate upon the hydrothermal treatment of Co metal substrates, mixed layered and spinel lithium cobalt oxide film was obtained on the surface of the Co metal substrate.