Advanced electrode/electrolyte materials for low and intermediate temperature solid oxide fuel cells

In this thesis study, various advanced materials were synthesized and investigated as electrode and electrolyte for low and intermediate temperature solid oxide fuel cells (SOFCs). Molybdenum vanadium oxide (V0.13Mo0.87O2.935) powder was obtained by a new method of reducing acidified vanadate and molybdate solution at 60 °C by passing hydrogen sulfide gas through the solution. The obtained mixed oxide was characterized by Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Thermogravimetry (TG) and Differantial Thermal Analysis (DTA) and used as anode in a fuel cell for the first time in literature. Its electrochemical behaviour and performance in the solid oxide fuel cell were carried out using Electrochemical Impedance Spectroscopy (EIS) and Fuel Cell Test Station.Three types of solid acids, rubidium phosphate tellurate, rubidium selenate with a secondary phase of rubidium hydroxide and cesium dihydrogen phosphate tellurite, were prepared and characterized by SEM, XRD, High Temperature X-ray Diffraction (HT-XRD), TG, DTA, Differential Scanning Calorimetry (DSC) and Energy Dispersive X-ray Spectroscopy (EDS) techniques. All solid acids were tested as electrolyte under various temperatures and atmospheres. Conductivity measurements were performed by EIS.The results from the study showed that molybdenum vanadium oxide is a good candidate to be used as a mixed ionic and electronic conducting anode in intermediate temperature SOFCs. In addition, it is revealed that advanced solid acid materials have a potential to be used as electrolytes for low and intermediate temperature SOFCs.