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−xTiO3−δ materials were synthesized by conventional solid-state reaction. The A-site deficiency limit in (La0.3Sr0.7)1−xTiO3−δ was below 10 mol% in 5%H2/Ar at 1500 °C. A-site deficiency level promoted the sintering process of (La0.3Sr0.7)1−xTiO3−δ. The ionic conductivity increased but the electronic conductivity decreased with increasing A-site deficiency level. The ionic conductivity of (La0.3Sr0.7)0.93TiO3−δ sample was as high as 0.2–1.6 × 10−2 S/cm in 500–950 °C and 1.0 × 10−2 S/cm at 800 °C, over twice of La0.3Sr0.7TiO3−δ. Its electrical conductivity was in the range of 83–299 S/cm in 50–950 °C and 145 S/cm at 800 °C. A-site deficiency improved the thermal stability of (La0.3Sr0.7)1−xTiO3−δ and ensured the material with a stable electrical performance in different atmospheres.