Lithium Diffusion in Li[sub x]CoO[sub 2] (0.45 < x < 0.7) Intercalation Cathodes

Abstract

Mass transport and thermodynamic properties of were studied by the potentiostatic intermittent titration technique (PITT). We determined the chemical diffusion coefficient and the thermodynamic factor (Θ) of Li in the region where exists as a single phase having either a rhombohedral or a monoclinic structure. Solid-state thin-film batteries were used in order to ensure a well-defined diffusion geometry. Both and Θ have minima at the phase boundaries of the Li vacancy ordered phase The self-diffusion coefficient of has a minimum at associated with the Li vacancy ordering. As the degree of ordering increases, nonmonotonic variations of Θ, and become more pronounced when approaching in © 2001 The Electrochemical Society. All rights reserved.