Synthesis and characterization of SrFeNiMoNbO ( x = 0, 0.05, 0.1, and 0.15) cathodes for solid oxide fuel cells.

Nb modified SrFeNiMoNbO (SFNiMNb, x = 0, 0.05, 0.1, and 0.15) materials are synthesized by the one-step combustion method, and their characteristics are investigated. According to the X-ray diffraction (XRD), all samples present single perovskite structures and scanning electron microscope (SEM) results indicate that all samples possess uniform porous structures. Additionally, the electrode conductivity is improved by doping Nb on the B′ site of SFNiM. From the X-ray photoelectron spectroscopy (XPS) results, the ratios of Fe/Fe and Mo/Mo vary with the Nb content, which leads to the conductivity change of SFNiMNb materials. For all the samples, SFNiMNb exhibits the best electrochemical performance with the lowest polarization resistance of 0.11 Ω cm and the highest power density of 1260 mW cm 800 °C in humidified H. The results indicate that SFNiMNb is a promising type of candidate cathode for solid oxide fuel cells. [ABSTRACT FROM AUTHOR]