Low-temperature preparation of ultrafine LiCoO2 powders by the sol-gel method

Abstract

Ultrafine LiCoO2 powders were prepared at lower temperatures by the sol-gel method using maleic acid as a chelating agent. The conditions of the sol formation from an aqueous solution of metal nitrates containing maleic acid, and the crystallization behaviour during the thermal decomposition of the gel precursors, were examined. The effect of the molar ratio of maleic acid to total metal ions, as well as the calcination temperature, on the physicochemical properties of the LiCoO2 powders was also investigated. It was found that polycrystalline low- and high-temperature (LT- and HT-) LiCoO2 powders could be obtained at calcination temperatures of 500 and 600 degrees C, respectively, with the calcination time of 1 h. They were found to be composed of very uniformly sized ultrafine particulates with an average particle size and a specific surface area of 30 nm and 12.4 m(2) g(-1) for LT-LiCoO2 and 60 nm and 8.8 m(2) g(-1) for HT-LiCoO2, respectively.