Influence of the nature of plasticizers in NiO-3YSZ tape-casting formulation on drying and mechanical behaviors of green tapes for fuel cell applications

Abstract

Tape casting is a process widely used on an industrial scale for manufacturing ceramic sheets with controlled thickness ranging from a few microns to millimeters. However, most of the slurry formulations rely on the use of toxic solvents and phthalate-based plasticizers. This study investigates the influence of alternative plasticizers on the drying kinetics, the stress development, and the mechanical behavior of green ceramic tapes formulated in a MEK/ethanol solvent system. The sintered microstructure is also addressed. Four plasticizers with distinct molecular structures were studied in fixed slurry formulations suitable for the production of solid oxide cell (SOC) anode supports based on NiO-3YSZ composites.

An original in-situ measurement by a cantilever deflection setup was employed to simultaneously monitor solvent evaporation, shrinkage, and in-plane stress evolution during drying. The results show that plasticizer chemistry plays a decisive role in the stress profiles observed during drying, with a distinct mechanism. The study distinguishes two dominant plasticizer roles—plastic and lubricant behaviors—linked to its chemical function and chain structure. Therefore, this work constitutes a practical guideline for selecting plasticizers to tailor stress development, packing density, and mechanical performance of ceramic tapes for SOC applications.