Solid oxide fuel cell anode surface modification by magnetron sputtering of NiO/YSZ thin film

NiO/ZrO₂-Y₂O₃ (NiO/YSZ) anode functional layers (AFL) with 16-60 vol.% of NiO were deposited onto NiO/YSZ anode substrates by magnetron sputtering, followed by annealing in air at 1200 °C. The optimal deposition conditions for NiO/YSZ were determined. NiO content in the films was varied by changing the oxygen flow rate during the sputtering process. The microstructure and phase composition of NiO/YSZ anode functional layer were studied by SEM and XRD methods. Anode functional layers were fully crystallized and comprised of grains up to 500 nm in diameter after reduction in hydrogen. Anode-supported solid oxide fuel cells (SOFC) with the diameter of 20 mm including the magnetron sputtered AFL, 4-microns thick YSZ electrolyte and La_0.6Sr_0.4Co_0.2Fe_0.8O₃/Ce_0.9Gd_0.1O₂ (LSCF/CGO) cathode were fabricated and tested. Electrochemical properties of the single fuel cells were investigated as a function of NiO volume content in AFL and AFL thickness.