Cobalt-Free BaFe0.6Zr0.1Y0.3O3−δ Oxygen Electrode for Reversible Protonic Ceramic Electrochemical Cells

Reversible protonic ceramic electrochemical cells (R-PCECs) are ideal, high-efficiency devices that are environmentally friendly and have a modular design. This paper studies BaFe 0.6 Zr 0.1 Y 0.3 O 3− δ (BFZY3) as a cobalt-free perovskite oxygen electrode for high-performance R-PCECs where Y ions doping can increase the concentration of oxygen vacancies with a remarkable increase in catalytic performance. The cell with configuration of Ni-BZCYYb/BZCYYb/BFZY3 demonstrated promising performance in dual modes of fuel cells (FCs) and electrolysis cells (ECs) at 650 °C with low polarization resistance of 0.13 Ω cm 2 , peak power density of 546.59 mW/cm 2 in FC mode, and current density of − 1.03 A/cm 2 at 1.3 V in EC mode. The alternative operation between FC and EC modes for up to eight cycles with a total of 80 h suggests that the cell with BFZY3 is exceptionally stable and reversible over the long term. The results indicated that BFZY3 has considerable potential as an air electrode material for R-PCECs, permitting efficient oxygen reduction and water splitting.