Development of intertwined nanostructured multi-phase air electrodes for efficient and durable reversible solid oxide cells

The development of nanostructured electrodes of solid oxide cells is largely hindered by the high temperature sintering process and limited in the loading and choices of catalytic phases. Here, a nanostructured multi-phase air electrode is fabricated via facile combination of Gd0.2Ce0.8O1.9 (GDC) decorated PrBa0.8Ca0.2Co2O5+δ (PBCC) and direct assembly approach. The highly flexible decoration process and the in situ formation of multi-phases lead to the formation of intertwined core-shell type nanostructures with intimate electrode/electrolyte interface. A cell with a 40 wt% GDC decorated PBCC electrode achieves a peak power density of 1.74 W cm−2 at 750 °C and an electrolysis current density of 1.77 A cm−2 at 1.3 V with excellent durability for 200 h. The combined decoration and direct assembly approach provides a unique and general pathway to develop a new class of nanostructured air electrodes for efficient and durable solid oxide cells.