Triple-component composite cathode for performance optimization of protonic ceramic fuel cells

The cathode of a protonic ceramic fuel cell must be able to facilitate ion and electron transfer, while simultaneously possessing a high catalytic activity for steam generation and the dissociation of gas-phase molecules. In this study, the performance of a cathode for protonic ceramic fuel cells is optimized by employing a triple-component composite cathode design, which integrates proton conductors, mixed electroniceionic conductors, and a catalytic layer. Additionally, two other composite cathodes are fabricated for comparison. Owing to its higher electrical conductivity but lower catalytic activity, the composite cathode with protonic ceramic and (Ba0.95La0.05) (Fe0.8Zn0.2)O3-delta (BLFZ) exhibits lower ohmic resistance but poor catalytic activity compared to the composite cathode with protonic ceramic and Ba(Co0.4Fe0.4Zr0.1Y0.1)O3-delta (BCFZY). The triple-component cathode is fabricated by infiltrating BCFZY into a composite cathode composed of BLFZ and protonic ceramic, and both the ohmic and non-ohmic resistances of the cathode are optimized in CH4 and H-2 fuels. In particular, the performance of CH4 fuel is significantly improved by adopting a triple-component cathode. These results suggest a possible contribution of the oxygen reduction reaction at the cathode to the reformation of CH4 at the anode. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.