Effects of A-site deficiency on the electrical conductivity and stability of (La, Co) co-doped SrTiO3 anode materials for intermediate temperature solid oxide fuel cells

•(La, Co) co-doped SrTiO3 was synthesized via solid state reaction.•Certain degree of A-site nonstoichiometry is introduced into La0.3Sr0.7Co0.07Ti0.93O3−δ.•A-site deficiency improves the thermal stability of (La, Co) co-doped SrTiO3.•A-site deficient (La, Co) co-doped SrTiO3 material is a potential anode material.

Improved anode materials are required for intermediate temperature operation of solid oxide fuel cells (SOFCs). (La, Co) co-doped SrTiO3 was synthesized via solid state reaction in this study. The results have demonstrated remarkable improvement of the ionic electrical conductivity and the thermal stability of (La, Co) co-doped SrTiO3 anode materials with A-site deficiency. The ionic conductivity of (La0.3Sr0.7)0.95Co0.07Ti0.93O3−δ sample is 0.7–1.9 × 10−2 S cm−1 from 500 °C to 900 °C and 1.4 × 10−2 S cm−1 at 700 °C in 5%H2/Ar. These values are nearly ten times higher than that of La0.3Sr0.7TiO3−δ at 700 °C. A-site deficiency improves the thermal stability of (La, Co) co-doped SrTiO3 and ensures stable electrical performance in different atmospheres. The possible charge compensation mechanism of (La0.3Sr0.7)0.95Co0.07Ti0.93O3−δ multicomponent system was also discussed.

Graphical abstractTemperature and atmosphere dependences of the electrical conductivity of (a) La0.3Sr0.7Co0.07Ti0.93O3−δ and (b) (La0.3Sr0.7)0.95Co0.07Ti0.93O3−δ.Figure optionsDownload full-size imageDownload as PowerPoint slide