Abstract Scope |
Solid-oxide fuel/electrolyzer cells have stringent materials requirements related to defects – from electrolyte materials with low ohmic losses for oxygen vacancy migration to electrode materials with high oxygen-exchange rates. There is incomplete understanding, however, of the structure-property relationships that would enable the rational design of better materials. Here, using epitaxial thin-film growth, synchrotron radiation, impedance spectroscopy, and density-functional theory, the impact of manipulating the structure of model electrolyte (e.g., La<sub>0.9</sub>Sr<sub>0.1</sub>Ga<sub>0.95</sub>Mg<sub>0.05</sub>O<sub>3–δ</sub>) and electrode (e.g., La<sub>1-x</sub>Sr<sub>x</sub>Co<sub>1-y</sub>Fe<sub>y</sub>O<sub>3</sub>) materials on the evolution of defect-mediate ionic conductivity and surface oxygen-exchange reactions are studied. We will leverage thin-film strain and orientation to show how unit-cell volume and octahedral rotations can be tuned independently to produce high ionic conductivity and how in half-cell systems different orientations of electrodes [e.g., (100), (110), and (111)] provide completely different potentials for catalytic response, thus answering existing questions in the field. |