Enhanced sinterability and conductivity insights of Nb2O5-Doped 8 mol% yttria-stabilized zirconia: Implications for low-temperature ceramic electrolytes

The study explored the effect of incorporating niobia (Nb2O5) at 1, 3, and 5 wt percent into 8 mol% yttriastabilized zirconia (8YSZ), made through a mechanochemical process. Niobia-doped 8YSZ samples were synthesized by a mechanochemical process and analyzed with methods including XRD, XPS, UV-Visible spectroscopy, particle size analysis, BET surface area analysis, FESEM-EDX, and EIS. Sintering was achieved at a reduced temperature of 1373 K, and all niobia-doped samples predominantly exhibited a tetragonal phase. Electrochemical impedance spectroscopy indicated that niobia doping inversely affected oxide ion conductivity-higher dopant concentrations resulted in lower conductivity. Nb-doped 8YSZ also displayed lower activation energy for conductivity compared to high-temperature (1473 K) sintered undoped 8YSZ, demonstrating equivalent performance. The combined benefits of lower sintering temperatures and enhanced ionic conductivities highlight crucial progress in developing cost-effective and energy-efficient electrolytes for clean energy applications.