Computational evaluation of new lithium-3 garnets for lithium-ion battery applications as anodes, cathodes, and solid-state electrolytes

In this work, we explore a set of new garnet oxide structures that can be used as an anode, cathode or solid-electrolyte in lithium-ion batteries (LIBs) using high-throughput density functional theory. We tested around 180 combinations of elemental substitutions for the dodecahedral X sites and octahedral Y sites in the Li3X3Y2O12 type garnet structure and identified 19 stable (i.e., on the convex hull) and 11 nearly stable (i.e., within 50 meV/atom of the convex hull) Li3 garnets with respect to decomposition to other stable phases in the Open Quantum Materials Database in the respective four-dimensional Li-X-Y-O chemical spaces. Our high-throughput screening strategy allows us to elucidate rules for garnet stability in terms of the ionic radii of the constituent elements. We evaluated the electrochemical window of these new, stable/nearly stable Li3-garnet compounds and classify each for potential applications as an anode, cathode, or solid-state electrolyte to be used in LIBs. Finally, Li+ ion diffusivity is calculated for the representative Li3Nd3W2O12 model system. The results we present here are expected to serve as a guideline for designing new garnet oxides for Li-ion battery applications.