Characterization of Ba1.0Sr1.0FeO4+δ cathode on La0.9Sr0.1Ga0.8Mg0.2O3-δ electrolyte for intermediate temperature solid oxide fuel cells

Ba1.0Sr1.0FeO4+delta (BSFO) with A(2)BO(4) structure as a cathode material for intermediate temperature solid oxide fuel cells (IT-SOFCs) is synthesized through an ethylene diamine tetraacetic acid (EDTA)-citrate process, and characterized by X-ray diffraction. Field emission scanning electron microscopy shows that BSFO cathode is well attached to the La0.9Sr0.1Ga0.8Mg0.2O3-delta (LSGM) electrolyte. The electrical conductivity measured by DC four-probe method increases as the temperature increases. A linear relationship between In(sigma T) and 1000/T indicates that the conducting behavior obeys the small polaron conductivity mechanism. Electrochemical performance of BSFO cathode on LSGM electrolyte is investigated in the temperature range from 500 degrees C to 800 degrees C. The results indicate that oxygen adsorption/dissociation process dominates cathodic reaction. Furthermore, the polarization resistance of BSFO cathode decreases with increasing temperature, and declines to 1.42 Omega cm(2) at 800 degrees C. These results show that BSFO can be a promising cathode material used on LSGM electrolyte for IT-SOFCs. (C) 2011 Elsevier B.V. All rights reserved.