(Keynote) Thermo-Electrochemical Interactions in Solid-State Batteries

Abstract

Solid-state batteries (SSBs) with a lithium metal anode hold tremendous promise to enable long-range electric vehicles and electric aviation. However, the successful realization of practical SSBs necessitates gaining a fundamental understanding of the complex nature of solid-solid interface evolution including the origin of various failure/degradation mechanisms such as lithium filament penetration, void growth and interphase formation. While the influence of chemo-mechanics at such interfaces has received significant research attention, the underpinnings of thermo-electrochemical coupling and the thermal stability of solid-solid interfaces still require critical investigation. In this presentation, we mechanistically delineate the spatio-temporal attributes and implications of thermal interactions in SSBs, including their critical role on interface stability of the anode, electrochemical-transport response in the cathode and crosstalk between the cathode/solid-electrolyte/anode interfaces. The effect of architectural asymmetry in a solid-state cell, consisting of a heat-generating cathode and a lithium-metal anode, on the occurrence of an intrinsic thermal gradient and associated degradation modes have been highlighted. A comprehensive description of mechanisms underlying the thermo-electrochemical stability of solid-solid interfaces in SSBs is presented.