Measurement of thermodynamic activity of zirconia in yttria-stabilized zirconia electrolyte for solid oxide fuel cell application

摘要

The Knudsen effusion mass spectrometry technique was applied to determine the activity of ZrO2 in 8 mol% yttria-stabilized zirconia (8YSZ) in the temperature range from 2200 K to 2500 K. The minor ZrO2+ ion current was used in calculations instead of the prevailing ZrO+ signal. The phase stability of the samples and their negligible interaction with the cell material was proved by XRD-analysis. The activity of ZrO2 was obtained to be 0.84 +/- 0.04 independent of temperature. This fact allows estimating the same value of activity in the operating temperature range of solid oxide fuel cells (SOFCs).