Synthesis and Characterization of Co-doped CeO2 Ceramic Electrolyte for IT-SOFC

Solid oxide fuel cells are electrochemical systems. One of the most important compounds in their structure is the ceramic electrolyte. The ceramic electrolyte property of the CeO2 compound is currently being investigated in many studies. In this study, we tried to synthesize different CeO2 compounds. Ce0.85-x-yLaxGdyO2 nanocrystalline powders were prepared via the hydrothermal method. Phases identification was completed through X-ray diffraction, SEM-EDS, thermal and impedance analysis. XRD data showed that all the obtained powders had a cubic fluorite structure. After examining the surface images, it was seen that the particle sizes were on the micron scale. Impedance measurements of the pelletized sample were also made. The Ce0.85-x-yLaxGdyO2 powder was sintered at 1250 °C. Increased conductivity value was calculated with increasing temperature. The best conductivity was observed at 750 oC and the conductivity value was 0.0022 S.cm-1. The results indicated that the degree of electrical conductivity was found to be low regarding the applications in intermediate temperature solid oxide fuel cells.