| Abstract Scope |
Grain boundaries in ceramics govern ion transport, mechanical response, and failure in energy materials, yet their coupled mechanisms remain poorly understood. In this talk, I present recent work on two model systems: CeO2 and Li7La3Zr2O12 (LLZO). Using electron holography combined with atom probe tomography, I directly correlate local electric fields with three-dimensional chemical distributions at CeO2 grain boundaries, revealing the chemical origins of resistive transport and opportunities for chemical control. I then examine dynamic Li penetration in LLZO, a failure mode driven by coupled electrochemical and mechanical processes. Through operando electron microscopy, nanomechanical measurements, and heterogeneous doping, I identify the mechanisms governing Li penetration and the critical role of grain boundaries in solid electrolyte failure. |