This study investigates the functionality of bi-layered electrolytes in intermediate temperature solid oxide fuel cells. A thin yttria-stabilized zirconia (YSZ) layer is expected to protect the underlying gadolinia doped ceria (GDC) electrolyte from being chemically reduced and significantly improve cell stability and durability. Although a thinner YSZ layer is preferable to minimize ohmic loss, there are limitations as to how thin the YSZ film can be and still serves as a valid protection layer. The limitation is partially attributed to the inter-diffusion and significant morphological changes during the high temperature sintering processes. In this study, a stable operation was demonstrated for extended duration (>80 h) with only a 28 nm YSZ layer (corresponding to a YSZ/GDC thickness ratio of 6.5 x 10(-5)) when limitations in both fabrication (

Keywords:solid oxide fuel cell;Atomic layer deposition;YSZ/GDC bi-layer;Sintering temperature;Ceria reduction