BaCo0.7Fe0.2Nb0.1O3-δ as cathode material for intermediate temperature solid oxide fuel cells

BaCo0.7Fe0.2Nb0.1O3-delta (BCFN) has been synthesized and characterized as cathode material for intermediate temperature solid oxide fuel cells (IT-SOFCs) using La0.8Sr0.2Ga0.83Mg0.17O3-delta (LSGM) electrolyte. X-ray diffraction results show that pure cubic BCFN perovskite phase can be obtained at 950 degrees C through solid state reactions of BaCO3,Co3O4. Fe2O3 and Nb2O5. The electrical conductivity of BCFN increases with the increase in oxygen partial pressure, indicating that BCFN is a p-type semiconductor. The polarization resistance of the BCFN cathode with LSGM electrolyte is only 0.06 Omega cm(2) at 750 degrees C in air under open-circuit conditions. The overpotential at a current density of 1 A cm(-2) in oxygen was only about 0.04 V at 750 degrees C. Peak power densities of 550, 770 and 980 mW cm(-2) have been achieved on LSGM-electrolyte supported single cells with the configuration of Ni-Gd0.1Ce0.9O1.95 vertical bar La0.4Ce0.6O2 vertical bar LSGM vertical bar BCFN at 700,750 and 800 degrees C, respectively. These results indicate that BCFN is a very promising cathode candidate for IT-SOFCs with LSGM electrolyte. (C) 2011 Elsevier B.V. All rights reserved.