Modification of sinterability and electrical property by Bi2O3 addition to La9.333Si6O26 for co-sintering with Gd0.1Ce0.9O1.95

Abstract Lanthanum silicate (LS) with 1–5 wt% Bi2O3 addition (LSB) was investigated for bi-layer solid oxide fuel cell (SOFC) electrolyte with gadolinia-doped ceria (GDC). Thermal shrinkage analyses suggested that adding more than 3 wt% Bi2O3 to LS approached to sintering behavior of GDC and Ni-GDC. Impedance measurement of GDC/LSB composites indicated that an additional resistive phase was formed in the grain boundary between GDC and LSB. Grain boundary resistance increased significantly with 5 wt% Bi2O3. This increase was inhibited in 1–3 wt% Bi2O3. Adding 3 wt% Bi2O3 to GDC/LSB is expected to densify electrolytes by co-sintering and limit the increase in resistance.