Cathode Materials for Reduced-Temperature SOFCs

Abstract
The progress toward a commercial solid oxide fuel cell (SOFC) continues to be a slow struggle due to materials, stacking, and system challenges. One long-term challenge has been the search for suitable cathode materials for use on intermediate (650-800°C) yttria-stabilized zirconia (YSZ) electrolytes and low-temperature (500-650°C) gadolinia-doped ceria (CGO) electrolytes. The present study has identified La(Sr)FeO3La(Sr)FeO3 and possibly Pr(Sr)FeO3Pr(Sr)FeO3 as potential cathode materials for YSZ. A La-deficient La(Sr)FeO3La(Sr)FeO3 cathode has achieved an area-specific resistance of 0.1 Ω cm2 at 800°C, with stable long-term performance. On CGO, Pr(Sr)CoO3,Pr(Sr)CoO3, Gd(Sr)CoO3,Gd(Sr)CoO3, and Sr(Co/Fe)1.5O3.25Sr(Co/Fe)1.5O3.25 have all achieved an area-specific resistance close to 0.1 Ω cm2 at 650°C, with relatively stable long-term performance, but further reduction in temperature to 600°C is necessary for efficient CGO operation. © 2003 The Electrochemical Society. All rights reserved.