Optimization of ScSZ/GDC bilayer thin film electrolyte for anodic aluminum oxide supported low temperature solid oxide fuel cells

Due to the poor chemical stability of CeO₂-based materials, doped CeO₂ electrolytes are generally used as a stabilized ZrO₂ protection layer/doped CeO₂ electrolyte bilayer structure. Since the ionic conductivity of stabilized ZrO₂ materials is lower than that of doped CeO₂ materials, the thickness of the ZrO₂ protective layer needs to be optimized. Thus, in this study, nano-porous anodic aluminum oxide template based scandia stabilized zirconia (ScSZ)/gadolinia doped ceria (GDC) bilayer electrolyte low temperature solid oxide fuel cells (LT-SOFCs) are successfully fabricated and investigated. The optimized thickness of the ScSZ protection layer is revealed by physical and electrochemical characterizations to maximize the performance of LT-SOFCs. The 160 nm ScSZ/400 nm GDC bilayer electrolyte LT-SOFC achieves a maximum power density of 252 mW · cm⁻² and an open circuit voltage of 1.02 V OCV at 450 °C. (paper)