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The reaction kinetics of the formation of LiCoO 2 during solid-state reaction was investigated using a non-isothermal approach at constant heating rates. The conversion ratios of the starting material of LiCoO 2 were calculated from thermogravimetric measurements. Analysis based on the differential method revealed that two diffusion-controlled models described the probable reaction mechanisms. The utilized integral method corroborated the fact that the reaction kinetics of the formation of LiCoO 2 was governed by Ginstling's diffusion-controlled reaction model. The activation energy of the formation of LiCoO 2 was calculated to be 163.6 kJ/mol. A combination of the differential and integral methods was demonstrated to effectively elucidate the reaction kinetics of ceramics and accurately determine the associated kinetic parameters.

Lithium cobalt oxide (LiCoO 2 ) powders, utilized as cathode materials in lithium–ion secondary batteries, have been synthesized through the emulsion process. When the emulsion-derived precursors are calcined at elevated temperatures, the amounts of residual Co 3 O 4 and organic species decrease and the crystallinity of LiCoO 2 gradually improves with a rise in the calcination temperature. After calcination at 800 °C for 1 h, monophasic LiCoO 2 powders with a R 3 m structure are successfully obtained. Compared to the traditional solid-state reaction, the emulsion process not only significantly curtails the reaction time to prepare LiCoO 2 , but also reduces the particle size. In the electrochemical test, both the specific discharge/charge capacity and the coulomb efficiency of LiCoO 2 increase with a rise in the calcination temperature. Increasing the calcination temperature results in the formation of pure LiCoO 2 without residual reactants, and also enhances the crystallinity of LiCoO 2 as well as the ordering arrangement of lithium and cobalt cations in the layered structure, thereby facilitating the intercalation and deintercalation of lithium ions. As a result, the combination of the emulsion method with proper calcination processes is highly successful in producing LiCoO 2 powders having large specific capacity and good cyclic stability along with high coulomb efficiency.

The surfactant effects on the microstructure and electrochemical properties of lithium cobalt oxide (LiCoO2) powders prepared from emulsion-derived precursors have been investigated in this study. The single-phase LiCoO2 powders with R 3 m structure are successfully prepared. The crystallinity and particle size of the obtained powders are varied with the amount of the surfactant used for preparing the emulsion solution. Reducing the amount of the surfactant results in improving the crystallinity and slightly decreasing the particle size of LiCoO2 powders. The LiCoO2 powders prepared from the emulsion with a small amount of the surfactant added exhibit high discharge capacity and high coulomb efficiency, as well as good cyclability. The crystallinity of LiCoO2 powders is considered to play an important role in determining the electrochemical properties.