Effect of turbostratic disorder in graphitic carbon hosts on the intercalation of lithium.

Abstract

The amount of lithium, ${\mathit{x}}_{\mathrm{max}}$, which can be intercalated in a graphitic carbon host is affected by the amount of turbostratic disorder in the host. Using electrochemical methods, we show that ${\mathit{x}}_{\mathrm{max}}$ in ${\mathrm{Li}}_{\mathit{x}\mathrm{max}}$${\mathrm{C}}_{6}$ is given by ${\mathit{x}}_{\mathrm{max}}$=1-P, where P is the probability of finding a random rotation or translation (turbostratic disorder) between adjacent graphite layers, implying that the interlayer spaces or galleries between randomly stacked layers do not host lithium ions. These ``blocked '' galleries influence the staged phases and the compositions of stage-1 (${\mathit{x}}_{\mathrm{max}}$) and stage-2 (${\mathit{x}}_{2\mathrm{m}\mathrm{a}\mathrm{x}}$) materials. A simple model is proposed to explain the variation of the composition of the stage-2 phase, ${\mathit{x}}_{2\mathrm{m}\mathrm{a}\mathrm{x}}$, with P.