Heterogeneous Composite Fibrous Cathode Undergoing Emphasized Active Oxygen Dissociation for La(Sr)Ga(Mg)O₃‐Based High‐Performed Solid Oxide Fuel Cells

Solid oxide fuel cells (SOFCs) are of great importance in terms of reducing operational costs and benefiting from system durability. However, SOFCs exhibit sluggish oxygen reduction reactions (ORRs) at cathodes. To overcome this, extensive research is focused on the development of cathodes with superior ORR properties for SOFCs. In this study, a fibrous composite cathode composed of strontium‐doped samarium cobaltate (SSC) and samarium‐doped ceria (SDC) is fabricated via electrospinning. Composite fiber cathodes prepared at specific ratios exhibit ORR properties and oxygen‐ion conductivity, which are attributed to the growth of small SSC particles in the fibrous electrode and nanolattice strain of SSC at the SSC and SDC interface. As such, the enhanced cathode performance contributes to an improvement in the power‐generation characteristics of SOFCs (1.33 W cm −2 at 1073 K using 300 μm thick La(Sr)Ga(Mg)O 3 electrolyte). This structural engineering of dual‐phase fiber is a promising design that promotes cathodic ORR performance.