Structural and electrolyte properties of Li4P2S6

Abstract

Experiment and simulations are used to investigate the structural and electrolyte properties of Li4P2S6. Compared with other thiophosphate materials, Li4P2S6 is quite stable, maintaining its crystal structure up to temperatures as high as 950 °C in vacuum and up to 280 °C in air. While its ionic conductivity is small, 2.38 × 10− 7 S/cm at 25 °C and 2.33 × 10− 6 S/cm at 100 °C, its Arrhenius activation energy of 0.29 eV is similar to technologically viable electrolytes. Computer simulations provide insight into the causes and effects of disorder in this material and also indicate that the mechanism of the ion conduction is dominated by interstitial sites.