Understanding the Relationship between Ink Rheology and Film Properties for Screen-Printed Nickel/Scandia-Stabilized-Zirconia Anodes

Optimization of SOFC electrode or electrolyte screen-printing ink processing conditions is critical to the reliable manufacture of high quality films with optimum properties. Hence, in this study, the relationship between the ink rheology and the screen-printed film properties were investigated using nickel/scandia-stabilized-zirconia (NiO/ScSZ) anode inks having various binder (0-5 wt%) and solid contents (20-35 vol%). Ink rheological tests showed increased particle network strength in the inks with increasing binder and solids content. The electronic conductivity and electrochemical performance of anode films also increased as a function of binder and solids content. These can be related to increased particle network strength within the inks, as confirmed from the rheological studies. In conclusion, from the perspective of ink rheology, screen-printability and performance, inks having 26 vol% solid with 3 wt% binder or 28-30 vol% solid with 2 wt% binder were determined as the most suitable for the manufacturing of high quality SOFC anode films with a thickness of around 10 μm.