Oxide-ion conducting ceramics for solid oxide fuel cells

Realization of a solid oxide fuel cell (SOFC) operating at 700°C on a hydrocarbon fuel or gaseous H₂ is an outstanding technical target. For the past 25 years, efforts to achieve this goal have been based on yttria-stabilized zirconia as the electrolyte, a NiO + electrolyte composite as the anode, a porous La_0.85Sr_0.15MnO₃ (LSM) metallic perovskite as the cathode, and a La_1–xSr_xCrO₃ ceramic as the interconnect material. This paper reviews progress in our laboratory on an alternate approach that would use a Sr- and Mg- doped LaGaO₃ perovskite as the electrolyte, a Sm-doped ceria (SDC) as the anode or as a buffer layer with a NiO + SDC composite as the anode, a mixed oxide-ion/electronic conductor (MIEC) as the cathode, and a stainless steel as the metallic interconnect.