Enhanced Stability of Ag-Based Cathodes via Integration with La _0.6 Sr _0.4 Co _0.2 Fe _0.8 O _3-δ Nanofibers for High-Performance Protonic Ceramic Fuel Cells

High Resolution Image Download MS PowerPoint Slide Protonic solid oxide fuel cells (P-SOFCs) are promising for efficient power generation at intermediate temperatures, yet the thermal instability of high-activity cathode materials remains a critical hurdle. Ag nanoparticles are ideal candidates due to their superior oxygen reduction reaction activity and electronic conductivity; however, their tendency to agglomerate at operating temperatures leads to a severe loss of active surface area. In this study, we developed a high-performance composite cathode via direct mixing of Ag nanoparticle slurry with one-dimensional La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3–δ (LSCF) nanofibers. Unlike traditional Ag-modified LSCF electrodes, this approach leverages the unique morphology of LSCF nanofibers to create a spatially restrictive environment that physically hinders the migration and coalescence of Ag nanoparticles. The 50:50 wt % Ag/LSCF nanofiber cathode achieved a peak power density of 614 mW/cm 2 at 800 °C, with a remarkably low polarization resistance of 0.07 Ω·cm 2 . Furthermore, the inclusion of LSCF nanofibers ensures superior morphological integrity of the Ag phase, leading to enhanced long-term operational stability relative to cells using pure Ag cathodes. This simple yet effective mixing strategy provides a scalable route for fabricating stable, high-power-density cathodes for P-SOFC applications.