Vapor-Mediated Infiltration of Nanocatalysts for Low-Temperature Solid Oxide Fuel Cells Using Electrosprayed Dendrites.

Electrode architecturing for fast electrochemical reaction is essential for achieving high-performance of low-temperature solid oxide fuel cells (LT-SOFCs). However, the conventional droplet infiltration technique still has limitations in terms of the applicability and scalability of nanocatalyst implementation. Here, we develop a novel two-step precursor infiltration process and fabricate high-performance LT-SOFCs with homogeneous and robust nanocatalysts. This novel infiltration process is designed based on the principle of a reversible sol-gel transition where the gelated precursor dendrites are uniformly deposited onto the electrode via controlled nanoscale electrospraying process then resolubilized and infiltrated into the porous electrode structure through subsequent humidity control. Our infiltration technique reduces the cathodic polarization resistance by 18% compared to conventional processes, thereby achieving an enhanced peak power density of 0.976 W cm at 650 °C. These results, which provide various degrees of freedom for forming nanocatalysts, exhibit an advancement in LT-SOFC technology.