Analysis of the structure and degree of crystallisation of 70Li2S–30P2S5 glass ceramic

Abstract

Heat treatment of Li₂S–P₂S₅ glasses to transform the glass to a glass ceramic enhances the ionic conductivity by precipitating a Li₇P₃S₁₁ metastable crystalline phase with high ionic conductivity. Although the precipitated phase is identical, the conductivity achieved varies depending on the heat treatment conditions. Solid-state ³¹P MAS NMR spectroscopy to investigate the structure of the glass ceramic in this study revealed a strong correlation between the ionic conductivity and the degree of crystallisation, in which the conductivity of the glass ceramic increased with increasing proportion of metastable Li₇P₃S₁₁ phase.