Synthesis of LiCoO2 using acrylic acid and its electrochemical properties for Li secondary batteries

LiCoO2 powders were synthesized by the sol-gel process at various temperatures using acrylic acid as a chelating agent and their structural and electrochemical properties were systematically investigated by X-ray diffraction (XRD), extended X-ray absorption fine structure (EXAFS), Electrochemical voltage spectroscopy (EVS), cyclic voltammetry (CV), and galvanostatic charge/discharge experiments. In this study, the gel-derived LiCoO2 samples calcined at 600 degrees C or above were found to be a well-developed layered high temperature-LiCoO2 (HT-LiCoO2). In the EVS of all the gel-derived HT-LiCoO2 samples, the peak potential separation of 10 mV was observed regardless of the calcination temperature, indicating that these samples have basically the same thermodynamic reversibility for intercalation/deintercalation of Li ions. The change of the main peak potentials and currents in cyclic voltammograms with increasing calcination temperature could be explained by the effect of particle size. (C) 1999 Elsevier Science S.A. All rights reserved.