Electrical and microstructural characterization of Gd-doped Ceria/Y-doped Zirconia bi-layer electrolyte prepared by tape casting

GDC-YSZ bi-layer SOFC electrolytes are an interesting manner to protect GDC electrolytes of the low oxygenpartial pressure present at anode-electrolyte interface. This oxygen partial pressure condition and hightemperatures during the operation of SOFC permit GDC electrolyte reduction injuring the performance ofSOFC. In this work, GDC-YSZ bi-layer electrolytes were prepared using double tape casting technique. Singlelayers of YSZ and GDC electrolytes were also prepared by the same technique for comparison. All sampleswere sintered at 1600 °C/2 h in air and analyzed by SEM and impedance spectroscopy technique. Agood adhesion was established between the layer GDC and YSZ and no cracks were detected despite the differentialfiring shrinkage. The electrical conductivity of GDC-YSZ bi-layer sample at 350 °C was 7.98x10-5S.cm-1 and for GDC and YSZ single layer samples electrical conductivities were 1.89x10-4 S.cm-1 and4.71x10-5 S.cm-1, respectively. These results show that GDC-YSZ bi-layer electrolyte is superior to YSZ singlelayer electrolyte