Preparation and conductivity measurement of 7-8 mol % YSZ and 12 mol % CSZ for electrolyte SOFC

Abstract

The study of 7YSZ (93% ZrO2-7%Y2O3), 8YSZ (92% ZrO2-8%Y2O3), and CSZ (88% ZrO2-12% CaO) as SOFC electrolytes have been carried out successfully. 7YSZ and 8YSZ powders were prepared by solid state reaction method of mixed Y2O3 and ZrO2 followed by calcination at 1350 °C for 1 hour, while CSZ was commercial products. Pellets of 7YSZ, 8YSZ, and CSZ were prepared by 1.2 gr, pressed at 40 MPa and sintered at 1550 °C for 4 hours. Rietveld refinement revealed that 7YSZ comprised 47.27% monoclinic, 52.65% cubic, and 0.008% Y2O3 cubic, while 8YSZ comprised 48.45% monoclinic, 49.32% cubic, 2.23% Y2O3 cubic and CSZ has 88% ZrO2 and 12% CaO. Ionic conductivity and activation energy were obtained from Cole- Cole Plot of impedance, the activation energy of 7YSZ=1.03eV, 8YSZ=0.96eV and CSZ=0.78eV.