Nanosized Ce_0.8Sm_0.2O_1.9 infiltrated GdBaCo₂O_5+δ cathodes for intermediate-temperature solid oxide fuel cells

In this paper, Ce_0.8Sm_0.2O_1.9 (SDC) nanoparticles modified GdBaCo₂O_5+δ (GBCO) cathodes were fabricated by an infiltration technique and evaluated for intermediate-temperature solid oxide fuel cells (IT-SOFCs). Good chemical compatibility between GBCO and infiltrated SDC was confirmed by X-ray diffraction (XRD) characterization. SDC nanoparticles (∼40 nm) formed continuous ionic-conducting phase on porous GBCO backbone, which contributed to significantly improved electro-catalytic property. At 600 °C, the composite cathode with 3.3 mg cm^-2 SDC loading exhibited encouragingly low R_p value of 0.1 Ω cm², which was much lower than 0.43 Ω cm² of pure-GBCO cathode. As revealed by PO₂ dependence of impedance spectra, the oxygen reduction reaction was mainly limited by charge-transfer processes. Furthermore, a stable operation of 80 h was obtained at 600 °C. Our study implies that infiltrated GBCO cathode is very attractive for application in IT-SOFC cathode.