2, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States
The realization of a low-cost, safe, reversible, high-areal capacity lithium metal electrode for solid-state batteries has remained elusive despite ongoing advances in anode protection using ion-conducting ceramics and glasses as well as organic and inorganic passivating layers. Here, I will outline a framework to understand the successes and failures of these differentiated materials platforms on the basis of their mechanical properties, transport properties, and partial molar volume considerations for solid-ion conductors relative to the lithium anode. Within this framework, I will also highlight an unexpected opportunity for suppressing lithium metal dendrites using soft solid-ion conductors. I will then detail the extent to which these predictions deliver on their promise, from early-stage discovery science and in-depth synchrotron hard x-ray techniques to platform maturation from coin cells to pouch cells.