LaNi 0.6Fe 0.4O 3–Ce 0.8Sm 0.2O 1.9–Ag composite cathode for intermediate temperature solid oxide fuel cells

Abstract

LaNi 0.6Fe 0.4O 3 (LNF), LNF–Sm 0.2Ce 0.8O 1.9 (SDC), and LNF–SDC–Ag cathodes on SDC electrolytes were investigated at intermediate temperatures using AC impedance spectroscopy. Results show that adding 50 wt.% SDC into LNF yields a significant low area specific resistance (ASR) which was found to be 0.92 Ω cm 2 at 700 °C. Infiltrating 0.3 mg/cm 2 Ag into LNF-50 wt.% SDC can improve the electronic conductivity and oxygen exchange reaction activity, and thereby remarkably decrease the ASRs. The ASR value of the LNF–SDC–Ag cathode is as low as 0.18 Ω cm 2 at 700 °C, and 0.46 Ω cm 2 at 650 °C. The long-term test shows that the LNF–SDC–Ag cathode may be a promising candidate for solid oxide fuel cells operating at temperatures lower than 650 °C.