Lithium intercalation inLixMo6Se8: A model mean-field lattice gas

Abstract

We show that lithium intercalation in ${\mathrm{Li}}_x{\mathrm{Mo}}_6{\mathrm{Se}}_8$ is described accurately by mean-field solutions to a single-parameter lattice-gas model. We present mean-field fits to the inverse derivative $\frac{\mathrm{dx}}{\mathrm{dV}}$ of the voltage $V$ of $\frac{\mathrm{Li}}{{\mathrm{Li}}_x{\mathrm{Mo}}_6{\mathrm{Se}}_8}$ cells at several temperatures. This is apparently the first fully quantitative description of $\frac{\mathrm{dx}}{\mathrm{dV}}$ for an intercalation system and the first realization of a three-dimensional mean-field lattice gas.