Mechanistic Interrogation of Thermal Stability in Solid-State Batteries

Solid-state batteries (SSBs), consisting of an inorganic solid electrolyte and a lithium metal anode are promising next-generation energy storage devices that can deliver high energy and power densities. However, the development of practical SSBs still requires overcoming fundamental challenges related to morphological evolution, transport-kinetics interaction, and electro-chemo-mechanical failure. While a wide range of candidate mechanisms leading to interface instability and failure onset have been studied, their mechanistic implication on the thermal stability at solid-solid interfaces is not understood yet. Due to various factors including the high reactivity of lithium metal, potential for oxygen liberation in the cathode, spatio-temporal evolution of thermal hotspots (e.g., during fast charging) and the propensity for internal short-circuit, the safety of SSBs needs to be critically evaluated. In this presentation, we assess the mechanistic role of thermo-electrochemical interactions, interface stability and interphase growth characteristics that can affect the thermal stability in SSBs.