PrBa0.5Sr0.5Co1.5Fe0.5O5+δ as air electrode for proton-conducting solid oxide cells

Proton-conducting solid oxide cell (H–SOC) is suitable for operation at lower temperatures. However, its commercialization still faces the problem of insufficient catalytic activity of air electrode. Here a triple ionic-electronic conductor PrBa0.5Sr0.5Co1.5Fe0.5O5+δ (PBSCF) is synthesized by glycine-nitrate method, and the PBSCF slurry was screen printed onto the surface of half-cell which is fabricated by aqueous co-tape casting to obtain the single cell with the structure of PBSCF ǀ BaZr0.1Ce0.7Y0.1Yb0.1O3-δ (BZCYYb) ǀ NiO-BZCYYb (active layer) ǀ NiO-BZCYYb (support layer). The peak power density of the single cell with dry air as oxidant and hydrogen as fuel at 750, 700, and 650 °C are 958.75, 872.78, and 709.22 mW cm−2, respectively. When the atmosphere is 20%H2O+80%air at air electrode side and hydrogen at fuel electrode side, the single cell operating as a proton-conducting solid oxide electrolysis cell shows high electrolysis current densities of 4299.4, 2744.6, 1711.8, and 974.6 mA cm−2 under 1.3 V at 750, 700, 650, and 600 °C respectively. Additionally, during the constant voltage electrolysis, the cell shows a good stability in 78 h at 650 °C. The results show that PBSCF is potential as air electrode of H–SOCs, especially in solid oxide electrolysis cell mode.