Ni-GDC and Ni-YSZ electrodes operated in solid oxide electrolysis and fuel cell modes

In the present study, solid oxide cells (SOCs) were operated in the electricity generation (solid oxide fuel cell, SOFC) mode and the hydrogen production (solid oxide electrolysis cell, SOEC) mode. The fuel electrodes fabricated with nickel-gadolinia doped ceria (Ni-GDC) and nickel-yttria stabilized zirconia (Ni-YSZ) composites were investigated. The correlations between changes in the microstructure and degradation of electrochemical performance are discussed. The degradation mechanisms correlated with Ni phase were found to be similar for Ni-GDC and Ni-YSZ electrodes. On the other hand, the stability of the ceramic phase differs significantly between the two electrode materials.