The potentiostatic intermittent titration technique and in situ X-ray diffraction were used to measure the dependence of the diffusion coefficient Do of lithium ions in graphite on the intercalation level X. Thin graphite electrodes provide an excellent opportunity to obtain highly-resolved data (with respect to X). A non-monotonic peak-shape dependence of log D0 versus X was observed, which correlated well with the corresponding dependence of the X-ray diffraction peak intensity and the cyclic voltammetric peaks. The results thus obtained were explained tentatively within a framework similar to the Daumas and Herold cluster model for the staged phase transition. Problems connected with the determination of the true values of D0 for porous electrodes were also discussed.

The Mechanism of Lithium Intercalation in Graphite Film Electrodes in Aprotic Media. Part 2. Potentiostatic Intermittent Titration and in situ XRD Studies of the Solid-State Ionic Diffusion. Levi, M.D., Levi, E.A., Aurbach, D.: Journal of Electroanalytical Chemistry, 1997, 421[1-2], 89-97