Synthesis and electrochemical properties of lithium cobalt oxides prepared by molten-salt synthesis using the eutectic mixture of LiCl-Li2CO3

Lithium cobalt oxide powders have been successfully prepared by a molten-salt synthesis (MSS) method using a eutectic mixture of LiCl and Li2CO3 salts. The physico-chemical properties of the Lithium cobalt oxide powders are investigated by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), particle-size analysis and charge-discharge cycling. A lower temperature and a shorter time (similar to 700 degreesC and 1 h) in the Li:Co=7 system are sufficient to prepare single-phase HT-LiCoO2 powders by the MSS method, compared with the solid-state reaction method. Charge-discharge tests show that the lithium cobalt oxide prepared at 800 degreesC has an initial discharge capacity as high as 140 mA h g(-1), and 100 mA h g(-1) after 40 cycles. The dependence of the synthetic conditions of HT-LiCoO2 on the reaction temperature, time and amount of flux with respect to starting oxides is extensively investigated. (C) 2001 Elsevier Science B.V. All rights reserved.