Appraisal of Ce1-y GdyO2-y/2 electrolytes for IT-SOFC operation at 500☌. 2010 22(3):660-674., and gadolinium-doped ceria (GDC) has shown to be amongst the most promising electrolytes 4 4 Steele BCH. International Journal of Energy Research. Solid oxide fuel cell (SOFC) technical challenges and solutions from nano-aspects. Efforts to find new electrolyte materials with high electrical conductivity at lower SOFC operation temperatures have identified ceria based electrolytes as a substitute for YSZ 2 2 Zhu B. Such high temperatures limit the viability of fuel cells due to long-term stability and require expensive materials for sealing, insulation, and interconnects. Classical designs employ yttria-stabilized zirconia (YSZ) as electrolyte, but it exhibits adequate ionic conductivity only at high temperatures (900-1000 ☌).
Solid oxide fuel cell (SOFC) has attracted considerable interest in the last few decades as a promising clean and efficient energy conversion device 1 1 Ormerod RM. Gadolinium-doped ceria cobalt addition zinc addition XPS SOFC
The total conductivity at 800 ☌ of pressed Zn-doped samples (6.7x10 -2 S/cm) and Co-doped samples (7.5x10 -2 S/cm) is similar for undoped samples (7.2x10 -2 S/cm) showing that Zn and Co has a positive effect on densification without compromising the electrical conductivity. Cobalt or zinc additions are effective as sintering aid, allowing peak sintering temperatures around 1000☌ to reach densifications above of 93% of theoretical density, showing no evidence for the presence of secondary phases. The powder samples were pressed and afterwards sintered by a two-step procedure, before characterization by X-Ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Impedance Spectroscopy (IS) in air. In this work, cobalt and zinc-doped Ce 0.8Gd 0.2O 1.9 samples were prepared starting from a commercial nanopowder and compared to the undoped material.