Effect of Ru/CGO versus Ni/CGO Co‐Infiltration on the Performance and Stability of STN‐Based SOFCs

Electrolyte supported cells (ESC), with Sc₂O₃‐stabilized ZrO₂ (ScSZ) electrolytes, Gd‐doped ceria (CGO) or M/CGO (M = Ni, Ru) infiltrated Sr_0.94Ti_0.9Nb_0.1O₃ (STN94) anodes and LSM/YSZ cathodes, were evaluated for their initial performance and long‐term stability. Power density for the Ru/CGO infiltrated cell reached ∼0.7 W cm^–2 at 850 °C, 4% H₂O/H₂, whereas the Ni/CGO infiltrated cell reached ∼0.3 W cm^–2, with the current morphologies and loadings. Operation at 0.125 A cm^–2, 850 °C, feeding 50% H₂O/H₂ to the anode and air to the cathode, for a period >300 h, showed superior stability for the Ru/CGO infiltrated cell, with ∼0.04 mV h^–1 degradation rate, when compared to the Ni/CGO infiltrated cell (∼0.5 mV h^–1). For the Ni/CGO case, the observed degradation has been tentatively linked to initial changes in the electrochemical active area and long‐term detrimental interactions between components.