Boosting and Robust Multifunction Cathode Layer for Solid Oxide Fuel Cells

Designing an efficient cathode and an accelerating sluggish oxygen reduction reaction (ORR) process are crucial to enhancing electrochemical outputs for solid oxide fuel cells (SOFCs). A novel multifunction layer (MFL) cathode that combines the Gd0.2Ce0.8O2−δ (GDC) interlayer with a La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) cathode functional layer is reported. After precisely controlling the concentration of an infiltration precursor solution, discrete and filmy LSCF on the GDC scaffold (MFL-D and MFL-F) can be prepared. Compared with the discrete-coating of LSCF (MFL-D), the film-like coating of LSCF (MFL-F) exhibits a lower initial polarization impedance of 0.093 Ω cm2 at 750 °C. The as-obtained SOFCs produce an enhanced peak power density of 0.93 W cm–2 and have successfully been operated at 0.5 A cm–2 for 400 h with a voltage degradation of only 16 mV. Oxygen ion transport model of the MFL-F is constructed and discussed. This work provides an important insight into designing efficient cathode for SOFCs.