2009 年 77 巻 2 号 p. 184-189
The compatibility of bismuth compounds as a sintering aid for (ZrO2)0.89(ScO1.5)0.1(CeO2)0.01 (ScSZ) electrolyte in intermediate-temperature solid oxide fuel cells (IT-SOFCs) has been discussed. Addition of 3 mol% BiO1.5 considerably decreased the sintering temperature of ScSZ of approximately 200°C and achieved the densification with a relative density above 95% at 1200°C. The solid solubility limit of BiO1.5 in ScSZ was less than 2 mol%. Dispersion of Bi2O3 at the grain boundaries correspondingly accelerated the growth of ScSZ grains and increased the grain boundary resistance at temperatures below 450°C. At elevated temperatures of 450–750°C, the electrical conductivity of the ScSZ after doping remained almost unchangeable in air and under reducing atmospheres. The results suggested that bismuth addition is promising to be applicable to a low-temperature co-firing fabrication of ScSZ based components for IT-SOFCs.
