Electrode/Electrolyte Interphase Studies of Ceria Based Electrolytes for IT-SOFCs

Abstract

Solid oxide fuel cells (SOFCs) require high operation temperatures (up to 800°C) in order to allow oxygen ion conduction through the ceramic electrolyte. Lowering SOFC operation temperature implies enhancing the transport and electrochemical properties of both electrolyte and cathode. In this work, the electrochemical performance of nanostructured La0.4Sr0.6Co0.8Fe0.2O3-d (LSCFO)/Ce0.8Gd0.2O2-d(CGO)/LSCFO and LSCFO/Ce0.8Nd0.2O2-d (CNO)/LSCFO symmetrical cells was investigated. The bulk conductivity is similar for both electrolytes, while the grain boundary and total conductivities is higher for the CGO electrolyte. Nevertheless, CGO electrolyte exhibits large pores that compromise its mechanical properties. In addition, cathode performance degrades in LSCFO/CGO/LSCFO cells.