Liquid-phase sintering of scsz electrolytes for solid oxide fuel cells

Reducing the manufacturing cost is urgently desired to lower the overall cost of solid oxide fuel cells (SOFCs). High energy expense in the sintering of the fuel cell components, especially the stabilized zirconia electrolyte, is one of the major sources for the cost. Reduction of the sintering temperature will save the energy for sintering. In this paper, liquid-phase sintering of scandia-stabilized zirconia (ScSZ) was achieved at lower temperatures by addition of bismuth oxide will be presented. Different fractions bismuth oxide powders ranging from 0 to 8 wt% were added into ScSZ powders. The powder was compacted into thin pellets using a uniaxial press at a pressure of 200 MPa. The pellets were sintered at different temperatures from 950 degrees C to 1450 degrees C which were varied according to the level of bismuth oxide addition. The microstructure of the sintered specimens was examined with SEM, TEM and XRD.