Effects of Copper Oxide Addition on the Electrochemical Properties of Samarium Doped Ceria Electrolyte for Intermediate Temperature Solid Oxide Fuel Cells

Low temperature sintering of samarium doped ceria (Sm_0.2Ce_0.8O_1.9, SDC) can be required for metal-supported solid oxide fuel cells. Sintering aids (mostly transition metal oxides) can be used to substantially reduce the sintering temperature which also has an effect on the overall electrochemical process. 0-10 mol% of copper oxide and lithium oxide are added to the ceria solid solution through glycine nitrate combustion process and sintered at different temperatures ranging between 1000 and 1450°C. Hebb-Wagner polarization method and Electrochemical Impedance Spectroscopy (EIS) are used to separately characterize ionic conductivity, electronic conductivity and transference numbers. The results show that the 5% CuO/SDC sintered at 1100°C leads to similar total conductivity as pure SDC sintered at 1450°C, but the electronic conductivity decreases, which is expected to contribute to reducing the mixed ionic/electronic nature of the electrolyte.