| Abstract Scope |
Electroceramics with superior ionic conductivity, fast interfacial kinetics, and high mechanical strength are promising for advanced energy systems. However, fundamental mechanisms of charge transport at interfaces and the related electro-chemo-mechanics are not well understood. In this talk, I will highlight my work on two electroceramic systems: an oxygen-ion conductor CeO2, and a Li-ion conductor Li7La3Zr2O12. First, I will present a unique approach to study charge transport at grain boundaries in polycrystalline CeO2: a combination of electron holography and atom probe tomography. The atomic visualization of electric fields and chemical species reveals the chemical origins of resistive grain boundaries. These insights suggest chemical tunability of grain boundary transport properties. Second, I will discuss dynamic Li penetration in Li7La3Zr2O12, a failure mechanism involving both electrochemistry and mechanics. Using operando scanning electron microscopy, nanomechanics, and heterogeneous doping, I will discuss the origins of Li penetration and a surface toughening strategy for brittle electroceramics. |