COMPARATIVE COMPUTATIONAL STUDIES OF LI, NA, AND MG INSERTION IN ELEMENTAL GROUP IV MATERIALS AND OXIDES: MATERIAL CHOICES FOR POST-LITHIUM BATTERIES

Abstract

In search for effective anode materials for sodium- and magnesium-ion batteries, we use density functional theory calculations to rationalize the storage properties of key anode material candidates. Specifically, we provide a consistent study of sodium and magnesium versus lithium for their insertion and diffusion in elemental group IV materials as well as in titanium dioxides. For the different systems the storage properties are computed, especially the intercalation energies and migration barriers. We also investigate how different factors can affect those storage properties. We estimate in particular the effect of phonons, generally neglected, and we consider the effect of p-doping. We also study the change in storage properties with the use of different phases of the same element or compound: more than one crystalline phase are considered for tin and titanium dioxide and the use of amorphous structures is investigated for silicon, carbon and titanium dioxide.