Donor- and transition metal-substituted SrTiO3: relevant issues in the development of ceramic components for SOFC anodes

Abstract

Due to phase stability requirements, the choice of alternative perovskite-type materials for ceramic SOFC anodes is essentially limited to chromite-, molybdate-, vanadate- or titanate-based systems. Donor-doped SrTiO3 combines remarkable stability in both oxidizing and reducing conditions, substantial electronic conductivity, and good prospects for inhibition of carbon deposition and sulfur-tolerance. The present lecture gives a brief overview and a comparative assessment of a variety of strontium titanate-based solid solutions as fuel electrode materials with emphasis on the defect chemistry, reducibility and corresponding effects on the electrical properties, thermomechanical compatibility with solid electrolytes, and electrochemical activity. The exemplified oxide systems are (Sr,Ln)TiO3 (Ln = La-Yb), (Sr,Pr)TiO3, Sr(Ti,Ta)O3 and Sr(Ti,V)O3 series including nomically cation-stoichiometric and A-site deficient formulations [1-4].