Electrical conductivity and structural stability of La-doped SrTiO3 with A-site deficiency as anode materials for solid oxide fuel cells

A-site-deficient (La0.3Sr0.7)(1-x)TiO3-delta materials were synthesized by conventional solid-state reaction. The A-site deficiency limit in (La0.3Sr0.7)(1-x)TiO3-delta was below 10 mol% in 5%H-2/Ar at 1500 degrees C. A-site deficiency level promoted the sintering process of (La0.3Sr0.7)(1-x)TiO3-delta. The ionic conductivity increased but the electronic conductivity decreased with increasing A-site deficiency level. The ionic conductivity of (La0.3Sr0.7)(0.93)TiO3-delta sample was as high as 0.2-1.6 x 10(-2) S/cm in 500-950 degrees C and 1.0 x 10(-2) S/cm at 800 degrees C, over twice of La0.3Sr0.2TiO3-delta. Its electrical conductivity was in the range of 83-299 S/cm in 50-950 degrees C and 145 S/cm at 800 degrees C. A-site deficiency improved the thermal stability of (La0.3Sr0.7)(1-x)TiO3-delta and ensured the material with a stable electrical performance in different atmospheres. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.