Microwave sintering of ceria-doped scandia stabilized zirconia as electrolyte for solid oxide fuel cell

摘要

In this work, the effect of microwave sintering on the properties of 1 mol% ceria-doped scandia stabilized zirconia (10Sc1CeSZ) was investigated. The sintering was carried out at temperatures 1300 degrees C and 1350 degrees C for 15 min using a 2.45 GHz microwave furnace. The sintering behavior of the microwave sintered ceramics was compared with that obtained via the conventional sintering at temperatures ranging from 1300 degrees C to 1550 degrees C with 2 h holding time. It was found that both sintering processes yielded highly dense samples with minimum density of 98% theoretical value. Phase analysis by X-ray diffraction revealed the presences of only cubic phase in all sintered samples. All sintered pellets possessed high Vickers hardness (13-14.6 GPa) and fracture toughness (similar to 3 MPa m(1/2)). Microstructural examination by using the scanning electron microscope showed that the grain size varied from 2.9 to 9.8 gm for the conventional sintered samples whereas the grain size of the microwave sintered ceramics was below 2 mu m. Electrochemical Impedance Spectroscopy study recorded the maximum ionic conductivity of 0.280 S/cm at 800 degrees C for the conventional-sintered sample at 1550 degrees C whereas a high value of 0.314 S/cm was measured for the microwave-sintered sample at 1350 degrees C. (C) 2016 Hydrogen Energy Publications LLC. Published.by Elsevier Ltd. All rights reserved.