Novel SrCe1 − xYbxO3 − α-(Na/K)Cl composite electrolytes for intermediate temperature solid oxide fuel cells

Abstract

In this study, novel SrCe1−xYbxO3−α (x=0, 0.05, 0.10, 0.15)-(Na/K)Cl composite electrolytes were synthesized at low temperature (750°C). The structural and microstructural properties of the composite electrolytes are observed by X–ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that the upper doping limit of Yb3+ in SrCeO3 is 15mol%. The XRD results shown that no chemical reactions take place between SrCe1−xYbxO3−α (x=0, 0.05, 0.10, 0.15) and NaCl/KCl. The SEM images revealed that NaCl/KCl is coated on the surface of SrCe1−xYbxO3−α (x=0, 0.05, 0.10, 0.15) act as a binder. The electrical conductivity is determined by impedance spectroscopy. The log σ~log (pO2) plots results indicate that the composites are almost pure ionic conductors. Finally, the excellent performance of SCYb15-NK is obtained with a maximum power density of 615mW·cm−2 at 700°C.