La0.5Sr0.2TiO3-δ Perovskite as Anode Material for Solid Oxide Fuel Cells

Abstract

Thermal, electrical, and electrocatalytical properties of the oxygen deficient La0.5Sr0.2TiO2.95 perovskite are studied in relation to their possible use as solid oxide fuel cell (SOFC) anode material. La0.5Sr0.2TiO2.95 is chemically stable under air and reduced atmosphere. Its thermal expansion coefficient is close to that of yttrium-stabilized zirconia (YSZ) under air and Ar/H2 (5%). No significant chemical expansion or contraction of La0.5Sr0.2TiO2.95 are observed between air and reduced atmosphere. La0.5Sr0.2TiO2.95 material has an electrical conductivity at 800 °C of 1 S cm−1 under moist hydrogen (H2/H2O (3%)), reaching 10 S cm−1 when LSTO is prereduced under Ar/H2(5%). The polarization resistance of La0.5Sr0.2TiO2.95 at 800 °C under moist hydrogen is about 1.5 Ω cm2, a value which has been obtained when including a thin CGO buffer layer between the dense YSZ electrolyte and the porous electrode.