A first-principles investigation was made of Li diffusion within the layered form of this material. Kinetic Monte Carlo simulations predicted that Li diffusion in LixCoO2 was mediated by a divacancy mechanism, when x was between 0 and 1; with isolated vacancies at infinite vacancy dilution. The activation barrier for divacancy migration depended strongly upon the Li concentration, and this resulted in a diffusion coefficient that varied over several orders of magnitude. It was concluded that the thermodynamic factor, in the expression for the chemical diffusion coefficient, played an important role at high Li concentrations.

Lithium Diffusion in Layered LiCoO2. A.Van der Ven, G.Ceder: Electrochemical and Solid-State Letters, 2000, 3[7], 301-4