Sm0.5Sr0.5CoO3 cathode material from glycine-nitrate process:: Formation, characterization, and application in LaGaO3-based solid oxide fuel cells

Cathode material Sm0.5Sr0.5CoO3 (SSC) with perovskite structure for intermediate temperature solid oxide fuel cell was synthesized using glycine-nitrate process (GNP). The phase evolution and the properties of Sm0.5Sr0.5CoO3 were investigated. The single cell performance was also tested using La0.9Sr0.1Ga0.8Mg0.2O3-delta (LSGM) as electrolyte and SSC as cathode. The results show that the formation of perovskite phase from synthesized precursor obtained by GNP begins at a calcining temperature of 600 degrees C. The single perovskite phase is formed completely after sintering at a temperature of 1000 degrees C. The phase formation temperature for SSC with complete single perovskite phase is from 1000 to 1100 degrees C. The SrSM2O4 phase appeared in the sample sintered at 1200 degrees C. It is also found that the sample sintered at 1200 degrees C has a higher conductivity. The electrical conductivity of sample is higher than 1000 S/cm at all temperature examined from 250 to 850 degrees C, and the highest conductivity reaches 2514S/cm at 250 degrees C. The thermal expansion coefficient of sample SSC is 22.8 x 10(-6) K-1 from 30 to 1000 degrees C in air. The maximum output power density of LSGM electrolyte single cell attains 222 and 293 mW/cm(2) at 800 and 850 degrees C, respectively. (C) 2006 Elsevier B.V. All rights reserved.