Probing local electrochemical activity within yttria-stabilized-zirconia via in situ high-temperature atomic force microscopy

Considerable interest in understanding interfacial phenomena occurring across nanostructured solid oxide fuel cell (SOFC) membrane electrode assemblies has increased demand for in situ characterization techniques with higher resolution. We briefly outline recent advancements in atomic force microscopy (AFM) instrumentation and subsystems in realizing real time imaging at high temperatures and ambient pressures, and the use of these in situ, multi-stimuli probes in collecting local information related to physical and fundamental processes. Here we demonstrate direct probing of local surface potential gradients related to the ionic conductivity of yttria-stabilized zirconia (YSZ) within symmetric SOFCs under intermediate operating temperatures (500–600 °C) via variable temperature scanning surface potential microscopy (VT-SSPM). The conductivity values obtained at different temperatures are then used to estimate the activation energy. These locally collected conductivity and activation energy values are subsequently compared to macroscopic electrochemical impedance results and bulk literature values, thus supporting the validity of the approach.