Foaming of filled polyurethanes for fabrication of porous anode supports for intermediate temperature-solid oxide fuel cells

The development of a tailored microstructure is considered essential for the development of anode-supported intermediate temperature-solid oxide fuel cells (IT-SOFCs) as it is expected to enhance kinetics at the triple phase boundary. In this study, the application of an in situ foaming technique for the preparation of Ni-yttria-stabilized zirconia (YSZ) cellular solids as an anode support for IT-SOFCs is presented. The cermet microstructure is dependent on the preparative route followed. The presence of contaminants in the commercial template precursor was found to be detrimental for electrical properties. A high-purity polyurethane was then formulated, and tailored Ni-YSZ foams were obtained with 87% porosity. The foam microstructure is characterized by a hierarchical architecture, with interconnected networks of Ni and YSZ particles, large pores related to the open cell structure, and a submicron porosity of the structural trabecular network, with a conductivity value of 80 S/cm at 700 degrees C.