Fabrication of Y2O3-Doped Zirconia/Gadolinia-Doped Ceria Bilayer Electrolyte Thin Film SOFC Cells of SOFCs by Single-Pulsed Laser Deposition Processing

An 8 -mol. % Y₂O₃-doped zirconia/10-mol. % GdO₂-doped ceria (YSZ/GDC) bilayer electrolyte and a Gd_0.5Sr_0.5CoO₃ (GSCO) cathode were deposited by a single-processing, pulsed laser deposition (PLD) method to fabricate anode support cells. No additional heat treatment was needed. Laser frequencies of 10, 20, and 100 Hz were used to deposit bilayer electrolytes between the NiO–YSZ (NiO:YSZ = 60:40 wt. %) anode substrate and the GSCO cathode thin film. The GDC thin film produced at 10 Hz was smooth, well-crystallized, and highly dense. The crystallinity of the GSCO cathode on the GDC was also improved. We concluded the GDC crystallinity affected the crystallinity of the cathode thin film. The resistivity of the YSZ single layer (5.7 μm thickness) was 1.4 times higher than that of the YSZ/GDC bilayer (YSZ 3.0 μm thickness, GDC 2.7 μm thickness) at 600 °C and that of the YSZ-GDC interface became low. The optimum YSZ thickness was found to be approximately 3.0 μm, at which thickness there was effective blocking of the passage of hydrogen molecules and electrons. A cell with a YSZ (3.0 μm thickness, fabricated at 20 Hz)/GDC (5.0 μm thickness, fabricated at 10 Hz) bilayer and GSCO cathode thin film exhibited a maximum power density of 400 mW·cm^–2 at a comparatively low temperature of 600 °C.