Chemo-Mechanical Degradation of Solid Electrolytes: Unveiling Fracture Mechanisms Through Experimental and Computational Synergy

Solid-state lithium batteries employing metallic lithium anodes and inorganic solid electrolytes are under active investigation as the next generation of energy storage devices. These batteries can improve safety relative to conventional liquid-electrolyte lithium-ion batteries while also enabling higher energy density. Their practical deployment, however, remains limited by lithium penetration through the solid electrolyte, a failure mode that couples electrochemical instability with fracture. The detailed mechanisms responsible for lithium-penetration-induced fracture remain largely unclear, despite their immense scientific and technological importance. This award will advance fundamental understanding of the fracture mechanics of inorganic solid electrolyte materials and ultimately facilitate the development and design of safer and more durable next-generation batteries. The project will also train the next generation workforce in science, technology, engineering, and mathematics equipped with interdisciplinary skills to tackle key energy challenges facing society. The multidisciplinary and collaborative work will expose graduate and undergraduate students, as well as local high school teachers and students, to the complementary roles of experimentation and modeling. The objective of this research is to establish a rigorous electrochemical fracture mechanics framework for solid electrolytes through tightly integrated experimental and computational approaches. The project will develop an operando experimental platform implementing phase-augmented digital image correlation for near-crack-tip deformation analysis. This measurement capability will provide high-precision, full-field deformation data during lithium-driven crack growth in inorganic solid electrolytes, including oxides, sulfides, and halides. Concurrently, an electro-chemo-mechanical phase-field model will be developed by coupling electrochemical reactions with rate-dependent mechanical deformation and damage in solid electrolyte materials. Integrated with experimental measurements and nonlinear field projection, the model will unravel the dynamic interaction between dendrite growth and crack propagation in both brittle and ductile solid electrolytes. Together, these tightly integrated experimental and computational efforts will provide a quantitative framework for understanding how lithium plating and crack growth interact in solid electrolytes and for predicting fracture response across electrolyte material systems. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.