Enhanced performance of LSCF cathode through surface modification

Mixed ionic-electronic conductors in the family of La _xSr _1-xCo _yFe _1-yO _3-δ (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 La _0.4875Ca _0.0125Ce _0.5O _2-δ (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 μL 0.25 mol L ^-1 LCC solution infiltrated into LSCF cathode, the cathodic polarization resistance was reduced by ∼60% (to ∼0.076 Ω cm ²) at 750°C, leading to a peak power density of ∼1.25 W/cm ², which is ∼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°C under a constant voltage of 0.7 V.