Solid-oxide fuel cells (SOFCs) are an energy conversion technology with unique potential to have the highest energy conversion efficiency with the least environmental impact, as well as broad fuel flexibility from renewable to conventional fuels. Lowering the SOFC operating temperature will further lower system and operational costs, increase long-term durability, and allow more rapid start-up, providing feasibility for load following and transportation applications. Unfortunately, at reduced temperatures, the thermally activated nature of ionic conduction and electrochemical reactions increase polarization resistances, thus decreasing cell and system performance. However, lower operating temperatures also create the opportunity to employ nanostructured materials with higher surface area-to-volume ratios and greater interphase and interfacial regions, which can greatly enhance electrochemical performance. Here, we review recent progress in the development of various nanostructured electrodes and electrolytes and discuss their effects on the enhancement of the electrocatalytic activity of oxygen reduction and fuel oxidation, as well as oxygen-ion conduction, in order to achieve high-performance low-temperature SOFCs.

Crucial features of materials evolution due to ion beam irradiation are often revealed only through studies of process dynamics. We review some significant examples of such experiments performed over the last 25 years with the Orsay in situ facility: a transmission electron microscope setup (with temperature stages operating between 4 and 1000 K) on a medium energy (3–570 keV) ion beam line. New results on nanocavity evolution and metal silicide nanoprecipitates in Si are presented briefly.We show that CoSi2 nanoprecipitate growth is mainly due to the constant Co atom contribution from the ion beam, and CoSi2 platelet growth is the result of a three-dimensional to two-dimensional growth mode transition.