High Ionic Conductivity with Improved Lithium Stability of CaS- and CaI(2)-Doped Li(7)P(3)S(11) Solid Electrolytes Synthesized by Liquid-Phase Synthesis

[Image: see text] Li(7)P(3)S(11) solid electrolytes (SEs) subjected to liquid-phase synthesis with CaS or CaI(2) doping were investigated in terms of their ionic conductivity and stability toward lithium anodes. No peak shifts were observed in the XRD patterns of CaS- or CaI(2)-doped Li(7)P(3)S(11), indicating that the doping element remained at the grain boundary. CaS- or CaI(2)-doped Li(7)P(3)S(11) showed no internal short circuit, and the cycling continued, indicating that not only CaI(2) including I(–) but also CaS could help increase the lithium stability. These results provide insights for the development of sulfide SEs for use in all-solid-state batteries in terms of their ionic conductivity and stability toward lithium anodes.