Synthesis, Electrical and Electrochemical Properties of Sr_(0.6)Ba_(0.4)Co_(0.3)Mn_(0.7)O_(3-δ) Cathode for Low-Temperature Solid Oxide Fuel Cells

摘要

A new pervoskite structure cathode material with composition of Sr_(0.6)Ba_(0.4)Co_(0.3)Mn_(0.7)O_(3-δ) SDC has been successfully synthesized by wet chemical method followed by sintering at 700o C for 4 hours and characterized by XRD and SEM. The particle size was determined between 20-30nm with the Scherer's formula and compared with SEM. Thermal properties were also investigated by TGA/DSC. Electrical conductivity measurement was carried out by the 4-probe DC method and was found 6 S/cm at air atmosphere. Electrochemical Impedance Spectroscopy (EIS) was also carried out at various temperatures using SDC ceria doped electrolyte to investigate the oxygen reduction mechanism. The activation energy was calculated 0.032eV via an Arrhenius plot. I-V and I-P curves were acquired in the temperature range of 400-550o C. The maximum power density reaches to 726mW/cm~2 at temperature 550o C.