Improved ionic conductivity of calcium doped ceria-salt chloride composites: The eutectic effect

摘要

Solid oxide fuel cells (SOFC) are considered as one of the most promising power generation technologies. The current high operating temperature (700-1000 °C) of SOFCs hinders their commercialization. Recently ceria -based composite materials are widely used because it is found to have a high conductivity below 600 °C. This paper analyzes the conductivity of the doped ceria based chloride composite systems, by varying the chloride combination as KCl and eutectic LiCl-KCl. The calcium doped ceria (CDC) has been prepared by the mechanochemical milling. The thermal decomposition process and structure of the samples were characterized by TGA and XRD respectively. The ionic conductivity of CDC/Salt composites was determined by electrochemical impedance spectroscopy (EIS). The CDC/ LiCl-KCl samples show significantly enhanced conductivity when compared to that of the CDC/KCl samples. This shows that the use of the eutectic salt in the composite electrolyte can effectively lower the operation temperature of SOFC due to improved ionic conductivity.