Characterizations of Synthetic 8mol% YSZ with Comparison to 3mol %YSZ for HT-SOFC

Abstract

In this work, Yttria (Y2O3) was successfully doped into tetragonal 3mol%yttria stabilized Zirconia (3YSZ) by high energy-mechanical milling tosynthesize 8mol% yttria stabilized Zirconia (8YSZ) used as an electrolytefor high temperature solid oxide fuel cells (HT-SOFC). This work aims toevaluate the densification and ionic conductivity of the sinteredelectrolytes at 1650°C. The bulk density was measured according to ASTMC373-17. The powder morphology and the microstructure of the sinteredelectrolytes were analyzed via Field Emission Scanning ElectronMicroscopy (FESEM). The chemical analysis was obtained with Energydispersive X-ray spectroscopy (EDS). Also, X-ray diffraction (XRD) wasused to obtain structural information of the starting materials and thesintered electrolytes. The ionic conductivity was obtained throughelectrochemical impedance spectroscopy (EIS) in the air as a function oftemperatures at a frequency range of 100(mHz)-100(kHz). It is found thatthe 3YSZ has a higher density than the 8YSZ. The impedance analysisshowed that the ionic conductivity of the prepared 8YSZ at 800°C is0.906(S.cm) and it was 0.214(S.cm) of the 3YSZ. Besides, 8YSZ has a loweractivation energy 0.774(eV) than that of the 3YSZ 0.901(eV). Thus, theprepared 8YSZ can be nominated as an electrolyte for the HT-SOFC.