Theory of anomalous voltage-discharge behavior for topotactic intercalation

Anomalous voltage-discharge behavior observed in topotactic intercalation m aterials is explained in terms of a lattice-gas model for interstitial site s with short-range nearest-neighbor repulsive interactions. For sufficientl y strong interactions a second order phase transition results in the format ion of fine structure of intercalated ions at certain critical concentratio ns. As a result a voltage-discharge curve shows a step-like behavior with n onanalytic features at the critical concentrations. (C) 2000 Elsevier Scien ce B.V. All rights reserved.