Modeling of Ionic Conductivity in Inorganic Compounds with Multivalent Cations

Abstract

This work is dedicated to search for promising ion-conducting crystals by using of high-throughput computer screening of the ICSD database of inorganic structures and quantum-mechanical modeling of ion transport. As a result, 246 magnesium-, calcium-, or strontium–oxygen-containing compounds are selected with 1D, 2D, 3D-migration maps of divalent ions that have not yet been studied as to the presence of ion conductivity. For ten structures with the simplest migration channel systems, including such well-known cation conductors, as Mg_0.5Ti₂(PO₄)₃, CaAl₂O₄, Sr_0.5Al₁₁O₁₇, quantum-chemical DFT calculations are carried out and cation migration energies are obtained. Among the studied compounds, the structures of Mg₃Nb₆O₁₁ and Mg₃V₂(SiO₄)₃ are characterized by the lowest migration energies of magnesium ions and small band gaps and can be considered as promising cation conductors for application in magnesium batteries.