Electrical conductivity of Ce0.8Gd0.2−xDyxO2−δ (0≤x≤0.2) co-doped with Gd3+ and Dy3+ for intermediate-temperature solid oxide fuel cells

Ionic Conduction Behavior in SmxNd0.15−xCe0.85O2−δ

“…It can be observed that by replacing some of Sm 3+ with Nd 3+ in Sm x Nd 0.15 − x Ce 0.85 O 2 − δ will lead to enhancement in the overall conductivity. Similar σ t enhancement was reported by Park et al for the Gd x Dy 0.2 − x Ce 0.8 O 2 − δ system on slight addition of Dy 3+ [14]. In addition, it was shown that the Dy-rich composition with slight addition of Gd 3+ will also exhibit an increase in σ t value.…”

“…It was shown that the variation of co-dopant ratio (x/y) within Sm x Nd y Ce 0.90 O 2 − δ does not lead to significant change in the grain ionic conductivity value [15]. However, it is important to note that the Park et al investigation was based on total ionic conductivity, while Kasse et al reported only the grain ionic conductivity [14,15]. The present work investigates the effect of varying co-dopant ratios on the grain ionic conductivity of Sm x Nd 0.15 − x Ce 0.85 O 2 − δ .…”

“…Recently, Park et al [14] investigated the ionic conductivity trend in various compositions of Gd x Dy 0.20 − x Ce 0.80 O 2 − δ at 800°C in air. It has been shown that the high ionic conductivity is achieved for co-doped compositions having slight amount (1-3 mol%) of second dopant.…”

Densification Behavior and Space Charge Blocking Effect of Bi2O3 and Gd2O3 Co-doped CeO2 as Electrolyte for Solid Oxide Fuel Cells

“…The small values of x 2 , R wp and R p indicate the good agreement between observed and calculated data, demonstrating the good quality of the refinement. As can be seen from Table 1, the lattice parameters increase gradually with the increase of Bi doping content, which is consistent with Vegard's law [25,26], considering the larger ionic radius of Bi 3+ (1.19 Å) [27] than that of Gd 3+ (1.06 Å) [28] in cubic fluorite structure. This result confirms that Gd 3+ and Bi 3+ are successfully co-doped into CeO 2 , forming a ceria-based solid solution with a single phase.…”

Low temperature fabrication of dense gadolinia-doped ceria electrolyte with enhanced electrical conductivity

“…From Table 1, it is worth noting that the GDC20 electrolyte prepared by coprecipitation combined with supercritical ethanol drying process virtually exhibits better electrical conduct performance than most of the reported gadolinium doped ceria. Fu et al [37] prepared GDC20 electrolyte by microwave-induced combustion synthesis and the total conductivity was 1.17 S m -1 at 700 o C; Zhang et al [38] obtained high-quality GDC material with different Gd doping concentration by conventional solid state reaction and the total conductivity of GDC20 was only 3.39 S m -1 when tested at 700 o C. However, recently, Park et al [39] prepared high-quality nano-sized GDC20 powders by a solution combustion process, using aspartic acid as fuel, and the densified compacts showed a high conductivity of 7.8 S m -1 at 700 o C. Therefore, preparation process is extremely significant for electrical performance. Under the same test conditions, the GDC20 ceramics fabricated in this work have the highest total conductivity of 5.39 S m -1 , primarily originating from the impressive low-temperature densification activity of the synthesized powder.…”