–– compounds as solid-state electrolytes for sodium-ion batteries: A combined DFT and MLIP investigation

Solid-state electrolytes represent a promising alternative to conventional liquid organic electrolytes in Na-ion batteries, due to their intrinsic thermal and chemical stability, as well as enhanced safety characteristics. Nevertheless, their practical application is hindered by inherently lower ionic conductivity compared to liquid counterparts. In the present work, Density Functional Theory in combination with Machine-Learned Interatomic Potentials was employed to evaluate the potential of compounds as solid-state electrolytes for Na-ion batteries. Among the investigated compounds, , , , and exhibit promising characteristics as solid-state electrolytes owing to their structural stability and favorable ionic transport properties. The calculated Na-ion conductivities at room temperature were 0.024, 0.142, 1.985, and 3.207 mS cm -1 , respectively. Furthermore, their electrochemical stability windows were evaluated and determined to be approximately 2.29 eV, underscoring their potential applicability as solid-state electrolyte in sodium-ion battery systems.