Investigation of cobalt-free perovskite Ba_0.95La _0.05FeO_3-δ as a cathode for proton-conducting solid oxide fuel cells

Cobalt-free perovskite Ba_0.95La_0.05FeO _3-δ (BLF) was synthesized. The conductivity of BLF was measured with a DC four-point technique. The thermal expansion coefficient of the BLF was measured using a dilatometer. The BaZr_0.1Ce_0.7Y _0.2O_3-δ (BZCY7) electrolyte based proton conducting solid oxide fuel cells (SOFCs) were fabricated. A composite cathode with BLF + BZCY7 was used to mitigate the thermal expansion mismatch with the BZCY7 electrolyte. The polarization processes of the button cell NiO-BZCY7/BZCY7/BLF + BZCY7 were characterized using the complicated electrochemical impedance spectroscopy technique. The open circuit voltage of 0.982 V, 1.004 V, and 1.027 V was obtained at 700 °C, 650 °C, and 600 °C, respectively, while the peak power density of 325 mW cm^-2, 240 mW cm^-2, and 152 mW cm^-2, was achieved accordingly.