Tetrahedral Tilting and Lithium-Ion Transport in Halide Argyrodites Prepared by Rapid, Microwave-Assisted Synthesis: Article No. 2500237

This study demonstrates a rapid, dry, microwave-assisted (MW) synthesis method that enables preparation of halide argyrodites Li6PS5X (X = Cl-, Br-, I-) in less than 20 min. The structures and ion transport properties of the resulting materials are compared with those synthesized by conventional solid-state synthesis methods. The microwave-assisted method leads to increased 4a/4d site disorder and elevated Arrhenius prefactors (..sigma..0), which lead to an order of magnitude improvement in the 30 degrees C ionic conductivity of MW-Li6PS5I. X-ray pair distribution function analysis (XPDF) reveals significant rotational disorder of the PS43- units, which is impacted by the synthesis method, choice of halide, and presence of S2-/ X- site disorder. These rotational displacements are strongly correlated with ion transport, specifically ..sigma..0 and entropy of migration (..delta..Sm). Overall, this study demonstrates a rapid synthesis route for preparing high-quality halide argyrodite solid-state electrolytes in less than 20 min, and further unravels atomistic insights into the interplay of structural disorder, rotational dynamics, and ion transport mechanisms.