Fast Lithium-Ion Conduction for Glass–Ceramics in the Pseudo-Ternary System Li₃PS₄–Li₄SnS₄–LiI (Supporting Information)

<p dir="ltr">Solid electrolytes are important for realizing all-solid-state lithium batteries and improving their performance. In this study, lithium-ion conducting glasses and glass-ceramics in the pseudo-ternary system Li₃PS₄–Li₄SnS₄–LiI are prepared using the mechanochemical method and subsequent heat treatment. The glass-ceramic 67(0.75Li₃PS₄·0.25Li₄SnS₄)·33LiI (mol%) electrolyte exhibits a high conductivity of 6.8 × 10⁻³ S cm⁻¹ at 25 °C because of the precipitation of a Li₁₀GeP₂S₁₂ (LGPS)-analog phase. The LGPS-analog phase is formed by adding LiI to the Li₃PS₄–Li₄SnS₄ system. An all-solid-state cell developed using a glass-ceramic electrolyte operates stably at room temperature.</p>