Unique porous thick Sm0.5Sr0.5CoO3 solid oxide fuel cell cathode films prepared by spray pyrolysis

Ultrasonic spray pyrolysis assisted by an electrostatic field was used to deposit thick Sm0.5Sr0.5CoO3 (SSC) films (>40 μm) as solid oxide fuel cell (SOFC) cathodes with a unique porous columnar structure. The high porosity and great thickness provided many active sites for reduction reaction. The space between columns, as well as the large pores (∼100 nm) inside the columns allowed gas molecules to diffuse quickly to the reaction sites; thus, very low interfacial resistance values (0.20 and 0.035 Ω cm2 at 600 and 700 °C, respectively) were obtained. Moreover, the high deposition rate, ease of operation in open air and low cost make the ultrasonic spray pyrolysis assisted by an electrostatic field a particularly useful method for preparation of films ideal for SOFC operation.