Preparation and Performance of Anode-supported LaGaO₃-based Electrolyte Solid Oxide Fuel Cells with Sm-doped CeO₂ Buffer Layers

Anode-supported solid oxide fuel cells (SOFCs) composed of NiO-SDC (Sm0.2Ce0.8O1.9) composite anode, thin tri-layer electrolyte, and La0.6Sr0.4Co0.8Fe0.2O3 (LSCF)-La0.9Sr0.1Ga0.8Mg0.2O3-δ (LSGM) composite cathode were fabricated. The thin 11 μm SDC/15 μm LSGM/13 μm SDC tri-layer electrolyte was prepared by centrifugal casting and co-firing technique. Cell tests in air as oxidant and humidified hydrogen as fuel show a maximum power density of 0.92 W /cm at 800°C. However, the open-circuit voltage (OCV) of these cells is 0.89 V which is lower than the Nernst potential. The above result is due to electronic conductivity in the LSGM layer, resulting from Ni impurities that entered during co-firing with the NiO-SDC anode. While the SDC buffer layers are introduced as buffer layers, impedance measurements indicate that both the ohmic resistance and the polarization resistance dominate the cell performance.