Facile Approach for Improving the Interfacial Adhesion of Nanofiber Air Electrodes of Reversible Solid Oxide Cells

Nanofibers have great promise as a highly active air electrode for reversible solid oxide cells (ReSOCs); however, one thorny issue is how to adhesively stick nanofibers to electrolyte with no damage to the original morphology. Herein, PrBa_0.8Ca_0.2Co₂O_5+δ (PBCC) nanofibers are applied as an air electrode by a facile direct assembly approach that leads to the retention of most of the unique microstructure of nanofibers, and firm adhesion of the nanofiber electrode onto the electrolyte is achieved by applying electrochemical polarization. A single cell with the PBCC nanofiber air electrode exhibits excellent maximum power density (1.97 W cm^-2), electrolysis performance (1.3 A cm^-2 at 1.3 V), and operating stability at 750 °C for 200 h. These findings provide a facile means for the utilization of nanofiber electrodes for high-performance and durable ReSOCs.