AC conductivity study of mechanochemically synthesized solid electrolytes of LiMPSCl (M = Ca, Mg, Ba, Zn, Al, Y).

Argyrodite-type solid electrolytes of LiPSCl doped with multivalent cations (Mg, Ba, Zn, Al, Y) were prepared a mechanochemical synthesis method. The lattice constant (), interplanar spacing (, , ), and micro-strain () showed that the doping elements were incorporated into the crystal structure of LiPSCl. The lattice constant and interplanar spacing of the doped samples were smaller than those of LiPSCl. The prepared samples exhibited a positive lattice strain, and the substituted samples exhibited higher strains than LiPSCl. The doped samples exhibited higher ionic conductivity than LiPSCl at 25 °C. LiAlPSCl exhibited the highest of approximately 2.36 × 10 S cm at 25 °C. The charge carrier movement at the grain boundary changing from long-range diffusion in LiPSCl to short-range diffusion in LiAlPSCl enhanced the conductivity.