Enhanced performance of LSCF cathode through surface modification

Abstract

Mixed ionic-electronic conductors in the family of LaxSr1-xCoyFe1-yO3-delta (LSCF) have been widely studied as cathode materials for solid oxide fuel cells (SOFCs). However, the long-term stability and the limited surface catalytic activity are still a concern. Here we report a new catalyst La0.4875Ca0.0125Ce0.5O2-delta (LCC), which can significantly enhance the performance and stability of LSCF cathodes when applied as a thin-film coating on LSCF surface. For example, with 5 mu L 0.25 mol L-1 LCC solution infiltrated into LSCF cathode, the cathodic polarization resistance was reduced by similar to 60% (to similar to 0.076 Omega cm(2)) at 750 degrees C, leading to a peak power density of similar to 1.25 W/cm(2), which is similar to 18% higher than that for the unmodified LSCF cathode in an anode-supported cell. In addition, stable power output was observed for over 500 h operation at 750 degrees C under a constant voltage of 0.7 V.