Reconstituting the microstructural properties and ionic conductivity of copper - doped yttria-stabilized zirconia via mechanochemical synthesis for intermediate-temperature solid oxide fuel cell applications.

The development of highly conductive and thermally stable solid electrolytes is crucial for the next generation of intermediate temperature solid oxide fuel cells (IT-SOFCs). This study investigates the influence of copper (Cu) doping on the microstructure and ionic conductivity of 8 mol. % yttria-stabilized zirconia (8YSZ) when sintered at lower temperatures. The mechanochemical synthesized 1, 3, and 5 wt. % Cu-doped 8YSZ compacts were extensively characterized their properties through a suite of analytical techniques like X-ray diffraction, Raman, X-ray photoelectron, UV–Vis diffused reflectance, particle size analyzer, BET surface area, Emission Scanning Electron Microscopy-Energy Dispersive X-Ray, and AC impedance. The results revealed enhanced ionic conductivity and sinterability, at reduced temperature of 1373 K, with the 5 wt. % Cu-doped 8YSZ demonstrating the highest ionic conductivity of 4.18 × 10−3 S cm−1 at 1023 K, alongside reduced activation energy of 1.14 eV. The lower sintering temperatures and consequential benefits in performance metrics suggest Cu-doping as an effective strategy for optimizing 8YSZ-based electrolytes lowering SOFC manufacturing costs without compromising performance for IT-SOFCs. [Display omitted] • 1. Copper -doped 8YSZ synthesized via mechanochemical process results in varied cubic, tetragonal, and monoclinic crystal phases. 2. Copper doping improves 8YSZ's ionic conductivity and sinterability for intermediate -temperature solid oxide fuel cells. 3. 5 wt. % Cu -doped 8YSZ achieves the highest conductivity (4.18 × 10−3 S cm−1 at 1023 K) and lowest activation energy (1.11 eV). 4. Copper doping is suggested to make 8YSZ-based solid oxide fuel cell electrolytes more cost-effective. [ABSTRACT FROM AUTHOR]