Synthesis and Characterization of Porous NiO/YSZ Electrode Materials Using Different Pore Formers

Solid oxide electrolysis cell (SOEC) cathodes require a good porosity and a fine microstructure in order to maximize the triple phase boundary (TPB) between electronic conductor, ionic conductor and the gas phase involved in the reaction. Nickel oxide and yttria stabilized zirconia (NiO/YSZ) composite, one of the most desired candidates for SOEC cathode material, is synthesized via the glycine-nitrate combustion process and mixed with corn starch and carbon black pore formers in order to observe how they modify its microstructure and porosity. XRD spectra indicate a distinct cubic phases of both NiO and YSZ. SEM micrographs were able to confirm that the addition of selected pore formers lead to an increase in porosities. Apparent and relative density measurements show that corn starch pore former produces the lowest density among the sintered pellets. EIS measurements revealed that samples with lower density also showed lower total conductivity.