Key points are not available for this paper at this time.
ABSTRACT Potassium‐conducting chalcogenides are attracting increasing attention as solid‐state conducting materials for potassium‐ion batteries. In this study, Inorganic Crystal Structure Database screening was performed for the first time to select new promising potassium‐ion conductors among ternary and quaternary sulfides and selenides. From over 853 compounds studied, using a geometrical‐topological analysis of free crystal space, we harvested 541 structures previously unreported as conductive materials in which periodic 1D, 2D, or 3D potassium migration maps were realized. Subsequently, the migration energy of the working cations was calculated for these structures using the bond valence site energy method, which allowed the selection of 37 structures with migration barriers below 1 eV, enabling 2D or 3D migration, and characterized by high crystal chemical stability. Kinetic Monte Carlo modeling then discovered nine structures with ionic conductivity exceeding 10 −6 S⋅cm −1 under standard conditions. For three ordered structures, K 6 CdSe 4 , K 3 GeS 3 , and K 4 SnSe 4 with the highest ionic conductivities, DFT nudged elastic band simulations revealed 3D conductivity maps with migration barriers below 0.35 eV. According to ab initio molecular dynamics simulations, all three compounds exhibited ionic conductivity exceeding 10 −5 S⋅cm −1 at 300 K. Dependencies between migration barriers and parameters of conduction channels were also revealed in the series of isostructural compounds.
Li et al. (Thu,) studied this question.