Atomic layer deposition of yttria-stabilized zirconia thin films for enhanced reactivity and stability of solid oxide fuel cells

We report the advantages of atomic layer deposition (ALD) for the fabrication of yttria-stabilized zirconia (YSZ) electrolyte. The reactivity and stability of anodic aluminum oxide (AAO)-based thin-film solid oxide fuel cells (SOFCs) are improved by applying ALD YSZ electrolyte. The fuel cell fabricated by ALD shows a peak power density of 154.6 mW cm−2 at 450 °C, whereas the fuel cell fabricated by sputtering demonstrates a peak power density of 66.2 mW cm−2. The amorphous and nanogranular microstructure of the ALD YSZ film is ascribed for a significant improvement in the cathodic reactivity of the AAO-based thin-film fuel cells. Moreover, the smooth and uniform surface of the ALD YSZ electrolytes mitigates the agglomeration of the Pt cathode layer, and thus the thermal stability of the thin-film fuel cell is remarkably improved at 450 °C.