Synthesis and characterization of solid electrolytes doped Bi2O3 and cathode materials for solid oxide fuel cells

In this study; production and characterization of Bi2O3 based solid electrolytes and perovskite cathode electrodes used in medium-temperature solid oxide fuel cells (IT-SOFC) were performed. Solid electrolyte samples were obtained using compounds Eu2O3, Dy2O3 and Bi2O3. Stable phase and medium-temperature solid oxide fuel cells, which can create the highest power density δ-Bi2O3 (cubic-fcc) phase was tried to be reached. Phase change time of the new samples, phase change temperature, effects of additive quantities, effects of additive type were determined. X-ray diffractometry (XRD) and differential thermal analysis and thermal gravimetry (TG/DTA) with binary (Eu2O3-Bi2O3) and triple (Eu2O3-Bi2O3-Dy2O3) doped powder materials were analyzed for crystal structure identification. Four point d.c. measurement technique. Eu2O3(x) Dy2O3(y) Bi2O3(1-x-y) (E5DyB; x: %5; y: %25-30-35 mol) were found to be close to solid electrolyte for medium temperature solid oxide fuel cell. It was observed that the electrical conductivity increased with the increase in the amount of two kinds of additive material Ln2O3. In addition, crystalline and electrical conductivity properties of the cathode electrode formed as Sr2FeBa(1-x) Eux (x: 25-40 mol %, SFBEux) were investigated. In the generated cathode samples, only BaCO3 and Eu2O3 additives were changed. The experimental results of the cathode electrodes were not fully stable. It was determined that homogeneous phases other than heterogeneous phases of solid electrolyte samples were used in industrial applications.