Stack Performance Optimization and 3.5 kW System Demonstration of Thin Metal‐Supported SOFCs Fabricated by Atmospheric Plasma Spraying

ABSTRACT This study extends our previous work on thin metal‐supported solid oxide fuel cells (MS‐SOFCs) fabricated via atmospheric plasma spraying (APS), focusing on enhancing stack performance through an innovative interconnect (IC) design. The newly developed IC configuration—featuring discrete cylindrical ribs and a hybrid flow field—significantly improved fuel and air utilization, reduced contact and polarization resistances, and enhanced thermal‐mechanical stability. Compared to conventional straight‐channel ICs, the new design increased single‐cell fuel utilization from 38% to 53% and improved five‐cell stack power output from 158 to 205 W at 0.8 V. Furthermore, four 36‐cell kilowatt‐class stacks exhibited excellent reproducibility, delivering power outputs above 1.2 kW at 750°C. Integration into a 3.5 kW SOFC system using methane steam reformate yielded stable operation with > 36% electrical efficiency. These results demonstrate that the proposed IC design not only boosts electrochemical performance but also facilitates scalable system‐level implementation of thin MS‐SOFCs.