In-Operando Observations of Ni-YSZ Patterned Fuel Electrodes Under SOFC and SOEC Operations

Abstract

In-operando observations and electrochemical measurements of patterned nickel (Ni) film electrodes under both solid oxide fuel cell (SOFC) and solid oxide electrolysis cell (SOEC) operations are conducted. Confocal laser scanning microscopy (CLSM) is applied to acquire the optical and laser microscopy images of patterned Ni film electrodes under polarization to study the Ni mobility on the yttria-stabilized zirconia (YSZ) surface. The Ni film dynamically spreads and breaks up only under SOFC operation, while such a phenomenon is not observed during SOEC operation. Ni coarsening occurs regardless of the operation mode. The morphological evolution of Ni qualitatively correlates with the changes of the current density. The Ni evolution in a single YSZ open window is well correlated with the total current density variation, which means that Ni movements of most of the YSZ windows are synchronized on the whole cell.