| Abstract Scope |
(Ce,Pr)O2-ä (PCO) is a mixed ionic/electronic conductor of interest for high-temperature electrodes. For efficient performance, electrode materials are often nanostructured, but the relationship between nanostructuring and electro-chemo-mechanical coupling has not been widely studied. In this talk I will describe investigations into redox chemical expansivity, transport behavior, and catalyst ex-solution on PCO nanoparticles, nanocrystalline ceramics, and nanostructured thin films. TGA, simultaneous dilatometry with EIS, atomistic simulations, and STEM-EELS reveal how modified interface defect chemistry gives rise to lower chemical strains, more ionic behavior, and non-linear strain-stoichiometry relationships at the nanoscale. Nanostructured Ni-PCO films enable a combined elastic and electrochemical driving force for facile catalyst ex-solution under mild conditions, observed with synchrotron NAP-XPS, AFM, and EIS. Ex-solution of Ni lowers polarization resistance and increases conductivity under fuel electrode conditions, attributed to the higher oxygen vacancy and electron concentrations. Implications for electrode design will be addressed. Funding: DOE grant DE-SC0023438 (MUSIC EFRC) |