高効率ジルコニア固体酸化物型燃料電池の開発(II) : 低温焼結スカンジア安定化ジルコニア固体電解質

Abstract

The effect of the addition of Bi_2O_3 on sintering, microstructure, crystal phase transformation, electrical conductivity, mechanical strength, and performance as electrolyte of Sc_2O_3-stabilized zirconia that was prepared using hydrolysis and homogeneous precipitation technique was investigated. By the addition of 1 mol% Bi_2O_3, sintering temperature of 10 mol% Sc_2O_3-doped zirconia (lOScSZ) was lowered over 300℃, growth of zirconia grains was accelerated, and dense sintered bodies with cubic phase were fabricated at 11)00 to 1100℃. Sufficient conductivity of 0.33 S/cm at 1000℃ and 0.12 S/cm at 800℃ for an electrolyte of solid oxide fuel cells (SOFC) was attained for 1 mol% Bi_2O_3-10 mol% Sc_20_3-codoped cubic zirconia (IBilOScSZ) sintered at 1200℃. A maximum power density of 1.61 W/cm^2 was obtained at 1000℃ using IBilOScSZ as the electrolyte in SOFC.