Designing highly active core/shell cathode materials for low-temperature PCFCs

Designing a cathode with exceptional oxygen reduction reaction (ORR) activity and durability at inter-mediate-to-low temperatures is vital to increase the improvement of solid oxide fuel cells (SOFCs), a captivating energy conversion technology with reduced environmental impact and high performance. Cathodes made of perovskite oxides have been developed extensively. Doping is a crucial method for modifying perovskites' lattice diffusion and surface exchange properties to achieve desired catalytic per-formances in a wide range of redox reactions, including oxygen reduction reactions (ORRs) for ceramic fuel cells (CFCs). The reported BaCo0.4Fe0.4Zr0.1Y0.1O3-& delta; (BCFZY) is a potential cathode in CFCs. Here, we sys-tematically explore the partial doping of B-sites with Al of varied content (from 5% to 30%) to further enhance the performance of BCFZY at lower temperatures. The polarization impedance of proton ion conducting fuel cells is lowest in Ba(Co0.4Fe0.4Zr0.1Y0.1)0.90Al0.1O3-& delta; (BCFZYA). The oxygen mobility, surface exchange kinetics, and bulk oxygen ion conductivity are all enhanced by 10%Al doping, as determined by EIS and performance tests.Moreover, Al doping led to the formation of the core-shell structure during the rearrangement of atoms. This results in an oxygen reduction reaction (ORR) of up to 0.157 cm2 at 520 oC on proton ion conducting electrolytes. As a result, BCFZYA appears to be a strong candidate for use in the cathode of advanced PCFCs (proton ceramic fuel cells).& COPY; 2023 Elsevier B.V. All rights reserved.