摘要: Nanofibers hold great promise as oxygen electrode materials in solid oxide cells (SOCs). However, conventional fabrication methods—such as slurry processing and high-temperature sintering—inevitably disrupt their delicate nano-architectures. Here, we propose an innovative self-assembly strategy mediated by current polarization to construct La0.6Sr0.4Co0.2Fe0.8O3-δ-Gd0.1Ce0.9O2-δ (LSCF-GDC) nanofiber composite film electrodes. This approach largely preserves the fibrous morphology while promoting coherent heterointerfaces, abundant active sites, and efficient electron/ion pathways. Benefiting from this tailored architecture, the electrode achieves a low polarization resistance of 0.117 Ω cm2 and a peak power density of 1.482 W cm-2 at 800 °C. Moreover, in CO2 electrolysis mode, it delivers an impressive current density of 2.30 A cm-2 at 1.8 V. These results establish nanofiber heterostructure films, enabled by current polarization assembly, as a powerful strategy to simultaneously enhance activity, durability, and mass transport, offering new opportunities for high-performance intermediate-temperature SOCs.