Stabilizing High-Temperature α-Li 3 PS 4 by Rapidly Heating the Glass.

High-temperature metastable phases exhibit superior characteristics compared to those of thermodynamically stable phases at room temperature. Although optimization of the compositions and crystallizations from glasses contribute to the stabilization of metastable phases at room temperature, the stabilization of the high-temperature α-LiPS phase is not yet reported. α-LiPS was successfully stabilized at room temperature, instead of the middle-temperature β-LiPS phase, rapid heating to crystallize the LiPS glass. The obtained electrolyte exhibited a high ionic conductivity of >10 S cm at room temperature. The crystallization of the glass rapid heating overcame the thermodynamic limitations in the preparation of the metastable crystals. Further development of materials nonequilibrium states should contribute to the design of high-performance materials.