Influence of CO2 on the Cathode Performance and Stability of La1-XSrxCo0.2Fe0.8O3-δ in Solid Oxide Fuel Cells

Thursday, 28 May 2015: 14:40
Continental Room A (Hilton Chicago)
D. Cetin, Y. Yu, H. Luo, X. Lin, U. B. Pal, S. N. Basu, and S. Gopalan (Boston University)
La1-xSrxCo0.2Fe0.8O3-δ is a high performance cathode material due to its mixed ionic and electronic conducting behavior that has widely been in used in solid oxide fuel cells (SOFCs). It has been shown that Sr segregates out of the lattice to the surface of the material and creates new phases in forms of SrO and SrCO3. Even though these surface phases are known to be insulators, their effects on oxygen surface exchange, oxygen transport, and on the overall cell performance remain as open questions.

In order to address the above issues, electrochemical impedance spectroscopy (EIS) was used to study cathode performance on cells of the configuration La1-xSrxCo0.2Fe0.8O3-δ (LSCF)/ gadolinium-doped ceria (GDC) barrier electrolyte layer/ yttria-stabilized zirconia (YSZ) electrolyte/porous (La0.8Sr0.2)0.95MnO3-YSZ counter electrode. LSCF performance was investigated in a dual atmosphere set up in CO2–free air and in the presence of CO2 at the intermediate operational temperature range of 600-800°C as a function of time.