Thermal Conditioning: An Effective and Inexpensive Strategy for Enhancing Ion Transport in Glass-Ceramics

Slow cooling and heating cycles at relatively low temperatures (25 to 100 °C) are demonstrated to be an effective and practical strategy for improving ionic conductivity in oxyhalide, halide, and thiophosphate glass-ceramic electrolytes. In this study, Li3PO4–LiI, Li3YBr6, and Li3PS4 were chosen as the representative systems. Thermal conditioning improves Li+-ion conduction by over 40%. Advanced characterizations using high-resolution NMR and XRD reveal four underlying mechanisms responsible for the increase in ionic conductivity, including the removal of low-conductivity impurities, the formation of high-conductivity phases, modification of the anion network, active cation redistribution, and enhanced ion mobility.