(Digital Presentation) Facile Fabrication of Nickel and Sc-Doped Zirconia Cermet Electrode Thin Film on YSZ Substrate Via Screen-Printing for Solid Oxide Electrochemical Cells

Abstract

Solid oxide electrochemical cells (SOCs) operating as either solid oxide fuel cells (SOFCs) or solid oxide electrolysis cells (SOECs) are widely known as promising advancements in green energy technologies for storage and high-efficiency energy generation. This study used a single screen-printing deposition method to fabricate a porous Nickel – scandia-stabilized zirconia (Ni-ScSZ) cermet electrode on a dense YSZ solid electrolyte substrate. The precursor powders were prepared via the glycine-nitrate combustion process. To investigate the effect of ink slurry solvent on the quality, structure, and morphology of the deposited films, ethanol, and alpha-terpineol were used. The screen-printed films were sintered at 1300°C for 6h and reduced under an Ar/5% H2 gas environment at 700°C for 2h to form porous electrodes. X-ray diffraction (XRD) analysis showed that all sintered NiO-ScSZ films exhibited cubic peak structures of both NiO and ScSZ. Scanning electron microscopy (SEM) micrographs and elemental mapping revealed finer morphology with good dispersion of NiO and ScSZ phases for sintered NiO-ScSZ films with alpha-terpineol as solvent. After exposure to Ar/5% H2 gas environment, a complete reduction of NiO to Ni was revealed by XRD for all Ni-ScSZ electrodes. Moreover, SEM micrographs of as-reduced samples showed an increase in porosity as oxygen was removed from NiO. Electrochemical impedance spectroscopy was used to determine the conductivity of the reduced Ni-ScSZ electrode films under Ar/5% H2 gas environment. The obtained total conductivity values upon reduction are 9.54x10-5 S/cm and 4.75x10-5 S/cm for ethanol and alpha-terpineol as solvents, respectively.