Effect of Ca2+ or Mg2+ additions on the electrical properties of yttria doped ceria electrolyte system

Electrical properties of ceria/carbonate nanocomposites

“…[12]. A new Ce 0.8 Sm 0.2−x Ca x O 2−ı /Na 2 CO 3 composite system which exhibits high co-ionic (H + /O 2− ) conductivity at 550 • C with a low activation energy of 0.238 eV [13] has been obtained by combining the two approaches: co-doping and composite effect.…”

Synthesis and Characterization Studies of Ca2+ and Y3+ Co-Doped Ceria-Na2CO3 Nanocomposite Electrolytes for Low Temperature SOFCs

“…Similar to single phase yttria doped ceria electrolyte, the impedance spectra show two partial semicircles at low temperatures and the arcs become smaller with the increase in operating temperatures. Usually the impedance plot shows three partial semicircles, high and medium frequency semicircles representing the bulk and grain boundary contributions and low frequency semicircle corresponds to electrode contribution [2]. The size of the impedance arc of the yttria doped ceria-carbonate composite is much smaller compared to single phase yttria doped ceria sample, which is reported earlier [5].…”

“…SOFC offers different benefits compared to other type of fuel cells as they require less expensive catalyst, fuel flexibility without the need of external reforming, more efficient etc. However, the current SOFC system with yttria stabilized zirconia (YSZ) electrolyte require high operating temperature (800-1000 °C) to obtain adequate conductivity [2]. This leads to several problems like interface reaction between the components, use of costly materials which can withstand the high operating temperature for long time operation.…”

“…One approach to reduce this problem and to increase the ionic conductivity is through co-doping. The co-doped samples have shown higher ionic conductivity than singly doped ceria [2]. Another approach to reduce the reduction of ceria is to make composites of ceria with various salts (sulfates, carbonates, halides etc.)…”

The Electrical Properties of Zr Doped Ce0.6Y0.4O2- δ Solid Electrolytes for Solid Oxide Fuel Cell Applications

“…In this temperature range, the conductivity value estimated from the low frequency plateau did not agree with that of the grain conductivity but agreed with the grain-boundary conductivity estimated from the impedance spectra. Therefore, we can assume that the plateau in the low frequency range is due to the polarization of the space charge at the grain boundary [13][14]. But at high frequencies, the charge can follow no longer with the frequency and the high frequency plateau corresponds to the grain conductivity.…”