Fabrication and characterization of Ni-SSZ gradient anodes/SSZ electrolyte for anode-supported SOFCs by tape casting and co-sintering technique

In this work, anode-supported solid oxide fuel cells (SOFCs) has been successfully prepared by tape casting and co-sintering technique. The structure contains the thin and dense 10% Sc₂O₃-stabilized-ZrO₂ (SSZ) electrolyte layer and the anode layers with continuous porosity gradient. The decomposition of organic additives and the shrinkage of green tape were analyzed by thermo-gravimetric and differential thermal analyses (TG-DSC) and thermal dilatometry. The microstructure morphologies and the porosity of anodes were examined by SEM and Archimedes method. The obtained anodes with continuous porosity gradient facilitate diffusion of the fuel gas and enlarge electrochemical active three phase boundaries. The open circuit voltage (OCV) was close to 1.1 V. The maximum power densities of single cell with graded Ni-SSZ anode were higher than non-gradient Ni-SSZ anode at 600, 650, 700, 750 and 800 °C and were 0.15, 0.30, 0.51, 0.70 and 1.00 W cm^-2, respectively. R_p of cell with graded Ni-SSZ anode was lower than that of non-gradient Ni-SSZ anode.