High-throughput search for new solid-state sodium-conducting materials among polyanionic oxides.

The development of new crystal materials for sodium-ion batteries is considered one of the most exciting fields in solid-state electrochemistry. To search for new sodium-ion conductors, we selected more than 200 structures from the Inorganic Crystal Structure Database (version 2023/1), consisting of four, five, and six elements with several oxygen-anionic groups. After the selection of 45 unique structures through geometrical analysis with the periodic 1D, 2D, and 3D migration maps, we calculated diffusion barriers and the crystal chemical stability index for each within the bond valence site energy method. Thus, we selected 21 different compounds to determine the room-temperature ionic conductivity and obtained 7 substances that have conductivity greater than 10−5 S cm−1. Among these prospective conductors, we identified a new class of Na2Ln(MO4)(PO4) (Ln = Er, Y, Tb, Ho; M = Mo, W) compounds with the layered sodium diffusion, which were not previously considered as possible conductors. [ABSTRACT FROM AUTHOR]