Temperature-dependent interfacial reactions between a sulfide argyrodite solid electrolyte and a lithium metal anode

Abstract

Conventional lithium-ion batteries face increasing demand for higher energy density and improved safety. Lithium (Li) metal all-solid-state batteries are considered a promising solution to meet these challenges, owing to the high energy density of Li metal anodes and the exceptional stability of solid electrolytes. However, challenges such as side reactions, dendrite formation, and the interfacial instability of Li metal anodes with solid electrolytes remain unresolved. These issues are further exacerbated by the limited understanding of their temperature-dependent behavior, which is critical for elucidating the kinetics and thermodynamic stability of these systems. In this study, we elucidate how temperature-dependent interfacial interactions between the Li metal anode and a sulfide-based argyrodite solid electrolyte influence battery reactions. We find that elevated temperatures enhance ion migration kinetics and mitigate side reactions, but also induce concentration polarization of charge carriers. This trade-off relationship leads to stable interfacial Li cycling at intermediate temperature ranges (ca. 80 °C), but results in a significant resistance increase at higher temperatures (ca. 120 °C) during cycling. These findings offer valuable insights for developing reliable Li metal electrode all-solid-state batteries.