Enhancing activity and stability of Ba0.5Sr0.5Co0.8Fe0.2O3-δ cathode by surface engineering with SrCoO3-δ nanoparticles in protonic ceramic fuel cells

Surface engineering has been considered as a promising technology to enhance the cathode's oxygen reduction reaction kinetics (ORR) for protonic ceramic fuel cells (PCFCs). In this work, the infiltrated SrCoO 3-δ (SCO) nanoparticles are incorporated onto the Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ (BSCF) cathode via the surface engineering. The effect of infiltration volume on the distribution density of nanoparticles for electrochemical performance is investigated. The polarization resistance (R p ) of 2 μL SCO-BSCF symmetrical cell shows a value of 0.108 Ω cm 2 at 700 °C in dry air, and exhibit higher stability than the bare BSCF cathode in wet atmospheres. Density functional theory (DFT) calculations show that SCO-BSCF facilitates the oxygen hydrogenation process. Molecular dynamics (MD) also indicate that the SCO nanoparticles are beneficial to the oxygen adsorption. Furthermore, the PCFC with 2 μL SCO-BSCF cathode achieves the maximum power density of 938.55 mW cm −2 at 700 °C. These findings suggest that the 2 μL SCO-BSCF could potentially be utilized as a cathode material for PCFCs.