Zn-Doped Perovskite as a High-Performance Bifunctional Cathode for Solid Oxide Cells

Solid oxide fuel cells (SOFCs) have garnered significant attention due to their high efficiency and pollution-free characteristics. The performance of SOFCs is critically dependent on the development of highly active and stable cathode materials. This study reports Zn-doped Pr0.5Ba0.5Fe0.9Zn0.1O3−δ (PBFZ) as a novel high-performance perovskite cathode material. Experimental results demonstrate that introducing a minor quantity of Zn into the B-site of the Pr0.5Ba0.5FeO3−δ (PBF) significantly increases the oxygen vacancy concentration, accelerates cathodic oxygen reduction (ORR) kinetics, and enhances tolerance to CO2, thereby leading to superior electrochemical performance. Tests revealed that a full cell employing PBFZ as the cathode achieved exhibiting a peak power density (PPD) of 762.9 mW cm–2 at 800 °C under fuel cell operation, representing an approximately 40% improvement compared to the PBF material. Furthermore, under CO2 electrolysis mode (800 °C, 1.5 V), a current density of 1.33 A cm–2 is achieved by the cell. These results highlight the potential of PBFZ as a viable cathode material applicable to both SOFCs and SOECs.