Cobalt oxide preparation from waste LiCoO2 by electrochemical-hydrothermal method

Cobalt ions, extracted from waste LiCoO2 by using a nitric acid leaching solution, are potentiostatically transformed into cobalt hydroxide on a titanium electrode and cobalt oxide is then obtained via a dehydration procedure. In linear sweep voltammetry, distinct cathodic current peak is observed and indicates that hydroxide ions are formed near the electrode via the electroreduction of dissolved oxygen and nitrate ions give rise to an increase in the local surface pH of the titanium. Under appropriate pH conditions, island-shaped cobalt hydroxide is precipitated on the titanium substrate and heat treatment of the cobalt hydroxide results in the formation of cobalt oxide. (C) 2002 Elsevier Science B.V. All rights reserved.