Fabrication of Highly Conducting Sc and Y Co-Doped ZrO₂ Solid Electrolyte Thin Film on a Porous Electrode Substrate via Facile Method for SOEC Applications

Scandium (Sc) and yttrium (Y) co-doped ZrO₂ (4Sc4YSZ) thin films were fabricated on a porous electrode substrate of NiO-YSZ using a facile drop-coating method. The 4Sc4YSZ powder was synthesized using sol-gel all alkoxide method while the 1:1 wt% composition of NiO and 8YSZ (NiO-YSZ) electrode substrate was synthesized via glycine-nitrate combustion method. The electrode substrate and solid electrolyte powders were characterized first before the half-cell fabrication. For the 4Sc4YSZ sol-gel derived powder, TG/DTA revealed that the powder stabilized at about 1000 degC which is complemented by FTIR results. From the FTIR spectra, the organic functional groups were completely removed after calcination at 1000 degC. The half-cell was then prepared via drop-coating of 4Sc4YSZ on a NiO/YSZ substrate and then characterized for its morphology and conductivity at intermediate temperatures. SEM-EDS revealed a well-distributed and homogeneous elemental composition of the 4Sc4YSZ solid electrolyte thin film on a porous Ni-YSZ electrode substrate. From the conductivity measurements done using electrochemical impedance spectroscopy (EIS), 4Sc4YSZ thin film can be a promising solid electrolyte material due to high total conductivity of about 1.2x10^-1 S/cmat 700 ^oC with 0.73 eV activation energy