Characterization of Scandia Stabilized Zirconia Doped With Various Bi2O3 Additions as an Intermediate Temperature Solid Oxide Fuel Cell Electrolyte

Abstract

Bi2O3 doped scandia stabilized zirconia systems have shown promise for use as electrolytes in intermediate temperature solid oxide fuel cells (IT-SOFC's). Sintering properties, crystal phase transformation, and electrical conductivity of the Bi2O3 doped Sc2O3–ZrO2 systems were investigated. The effect of Bi2O3 doping from 0 mol % to 2.0 mol % and different sintering temperatures on the properties and performance of the electrolyte were examined. The presence of Bi2O3 aided the sintering process and better sintering for the doped system was achieved at lower temperatures. The cubic phase was successfully stabilized at room temperature with concentrations of 1 mol % and 2 mol %Bi2O3 sintered at 1100–1400°C. The achievement of a cubic structure depends on both the Bi2O3 concentration and the sintering temperature. Higher electrical conductivity was achieved with Bi2O3 doped Sc2O3–ZrO2 systems than 10ScSZ below 600°C. A maximum conductivity of 1.68×10−2 S/cm at 700°C was obtained for 2 mol %Bi2O3 doped sample sintered at 1100°C.