The Reactions of Li[sub 0.5]CoO[sub 2] with Nonaqueous Solvents at Elevated Temperatures

Abstract

Differential scanning calorimetry (DSC), accelerating rate calorimetry (ARC), and X-ray diffraction experiments on the reaction of Formula in various solvents have been performed. In the presence of sufficient solvent the reaction proceeds in a clear stepwise manner through solid phases as a function of temperature as Formula Accompanying these changes are solvent combustion reactions due to the evolved oxygen that realease large amounts of heat. If there is only a small amount of solvent present relative to the amount of Formula the last step of the reaction does not occur, at least at temperatures below 450°C. A kinetic description for the stepwise reaction of Formula in ethylene carbonate (EC)/propylene carbonate (PC) was developed using successive Avrami-Erofeev reaction models. The kinetic triplets obtained from DSC experiments were then used to accurately predict a number of ARC experiments of Formula in EC/PC, giving confidence in the determined kinetic triplet.