A-site deficient La 0.4 Sr 0.4 TiO 3 -Ce 0.9 Gd 0.1 O 1.95 composites as efficient and redox stable anodes for solid oxide fuel cells

Abstract

La-doped strontium titanates have attracted much interest as promising reliable ceramic anodes for solid oxide fuel cells (SOFCs) owing to their superior redox-stability. Moreover, recent studies demonstrated that A-site deficiency of the La-doped SrTiO 3 perovskite could effectively promote conductivity and catalytic activity, simultaneously. In this study, we developed the LST44-Ce 0.9 Gd 0.1 O 1.95 (GDC) composite anodes, and investigated their electrochemical performance and redox stability on La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3−δ (LSGM) electrolyte-based SOFCs. During galvanostatic long-term stability tests combined with in situ redox cycles, power out-put performance of the LST44-GDC employed SOFC was initially increased by ∼53% to 0.26 W cm −2 and maintained the high performance over 350 h at 800 °C. Analysis of the accumulated electrochemical impedance spectra during the long-term stability test showed that the electrochemical activity of the LST44-GDC anode was promoted at the initial redox cycling. Consequently, this study demonstrates that A-site deficient LST44-GDC is a promising material as an efficient and redox stable SOFC anode. © 2019 Elsevier B.V.