Chemo-Mechanical Challenges in Solid-State Batteries

Solid-state batteries (SSBs) could exhibit improved safety and energy density compared with traditional lithium-ion systems, but fundamental challenges exist in integrating solid-state electrolytes with electrode materials. In particular, the (electro)chemical evolution of electrode materials and interfaces can often be linked to mechanical degradation due to the all-solid nature of these systems. This review presents recent progress in understanding the coupling between chemistry and mechanics in solid-state batteries, with a focus on three important phenomena: (i) lithium filament growth through solid-state electrolytes, (ii) structural and mechanical evolution at chemically unstable interfaces, and (iii) chemo-mechanical effects within solid-state composite electrodes. Building on recent progress, overcoming chemo-mechanical challenges in solid-state batteries will require new in situ characterization methods and efforts to control evolution of interfaces.