Influence of Aliovalent Cation Substitution and Mechanical Compression on Li-Ion Conductivity and Diffusivity in Argyrodite Solid Electrolytes

All-solid-state batteries employing sulfide superionic conductors demand new electrolyte materials with excellent Li-ion transport properties. We report on dual-modified superionic conductors in the Li-argyrodite family. In these materials prepared by a rapid synthesis method, aliovalent doping of the Li+ site with Ca2+ or Al3+ generates vacancies which improve Li+ diffusion and conductivity. This is confirmed by pulsed-field gradient (PFG)-NMR …