Pure cobalt compound such as cobalt oxalate has been recycled from industrial wastes. In addition, the recycled cobalt compound has been used as a reactant to prepare lithium cobalt oxide for cathode material. During the recycling procedure, the ultrasonic has been applied to control the particle shape and size of both the recycled cobalt compound and the prepared lithium cobalt oxide. The structural and compositional purity of the prepared materials has been confirmed by the analyses of chemical element, X-ray diffraction (XRD) pattern, Xray photoelectron spectroscopy (XPS) and Raman spectroscopy. The highest discharge capacity of lithium cobalt oxide prepared in various synthetic conditions is 133.4 mA h/g (3.0-4.3 V). (C) 2004 Elsevier B.V. All rights reserved.