A Comparative Study on the Densification Behavior of Yttria-Stabilized Zirconia Electrolyte Powders

Abstract

We compared the densification behavior of three different types of 8 mol% yttria-stabilized zirconia (YSZ) powders used as the electrolyte for solid oxide fuel cells (SOFCs): (i) TZ-8Y from Tosoh (Japan), (ii) MELox 8Y from MEL Chemicals (UK), and (iii) YSZ-HT from Huatsing Power (China). The YSZ powders were pressed to form disc-shaped pellets that were sintered at different temperatures ranging 1200–1400 °C. Among the three YSZ powders, MELox 8Y showed the best densification behavior at lower sintering temperatures with 93 and 96% of the theoretical density at 1250 and 1300 °C, respectively. Although YSZ-HT showed higher sintering rate than TZ-8Y, a sintering temperature of 1350 °C was required for both the powders to reach a theoretical density ≥95%. Our results indicate that different factors besides the particle size play a significant role in determining the sintering rate and densification behavior of the YSZ electrolyte.