Low temperature sintering of 8YSZ electrolyte film for intermediate temperature solid oxide fuel cells

At 200 °C, 8 mol% yttria doped zirconia (8YSZ) nanocrystals were synthesized through a hydrothermal process for 24 h. Characterizations revealed that the as-synthesized 8YSZ powder was weakly agglomerated and had a surface area of 121 m2/g and an average grain size of ∼9 nm. Sintering behaviors of the 8YSZ powder were studied via isothermal and non-isothermal experiments. It demonstrated that the powder has high sintering activity, where 8YSZ green films prepared via dip coating using the slurry directly formed by the hydrothermal process can be fully densified at 1000 °C. The thickness of the sintered film can be controlled through adjusting the 8YSZ concentration in the slurry and repeating the dipping-coating-sintering cycle. The superior sinterability achieved in the present study was mainly attributed to the high green density and homogeneity of the green bodies with narrow-distributed interparticle pore structure. The low sintering temperature is of great practical importance for improving film quality and facilitating co-sintering of 8YSZ films together with other SOFC components.