Ln1−Sr CoO3(Ln = Sm, Dy) for the electrode of solid oxide fuel cells (original) (raw)

The perovskite-type oxides were synthcsilcd in the series of Ln, _,SrVCoO, (Ln = Sm, Dy). The formation of solid solutions in Dy , SrXCoO, was limited, compared with that in Stn,_,SrXCoO,. The electrical conductivities of the sintcrcd samples were tneasurcd as a function of x in the temperature range 30 to IOOO"C. The highest conductivity of around 500 S/cm at 1000°C was found in Sm,, ,Sr(, ,CoO,. The reactivity of all the samples with YSZ was exatnined at 800-1000°C for 96 h. The Sr-doped pcrovskite oxides were more rcactivc with YSZ and produced SrZrO, at YOO"C after 96 h. However, no reaction product between SmCoO, and YSZ was observed at 100°C for 96 h. The cathodic polarization of the oxide electrodes, sputtered on yttria stabilized Lirconia (YSZ), was studied at 800 IO(X)"C in air. SmCoO, shows no degradation of the electrode performance at higher temperatures. The thermal expansion tncasurcments on the sintcrcd samples were carried out from room temperature to 1000°C. Large thertnal expansion coefticients were found in these samples.