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The electronic conductivity of Ce 0.8 Pr x Tb 0.2−x O 2−δ (x = 0, 0.05, 0.10, 0.15, 0.20) was determined in the oxygen activity range a O2 ≈ 10 3 -10 −17 at 700-900 • C by Hebb-Wagner polarization. The electronic conductivity of all the Ce 0.8 Pr x Tb 0.2−x O 2−δ compositions was significantly enhanced as compared to that of Ce 0.9 Gd 0.1 O 1.95−δ , and was found to increase with increasing Pr/Tb ratio. The oxide ion mobility in Ce 0.8 Pr x Tb 0.2−x O 2−δ is similar to that in Ce 1−2δ Gd 2δ O 2−δ at the same oxygen vacancy concentration. Based on the measured ionic and electronic conductivities, fluxes through thin film Ce 0.8 Pr x Tb 0.2−x O 2−δ membranes were calculated. Calculated fluxes exceed 10 Nml min −1 cm −2 under oxyfuel relevant conditions (T = 800 • C, a O2,permeate side = 10 −3 ). Hence, in terms of transport properties, these materials are promising for this application. Interference between the ionic and electronic flows has a significant positive effect on the deliverable oxygen flux, as evaluated for Ce 0.8 Pr 0.2 O 2−δ . 1

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“…13 as a function of the oxygen activity of the permeate gas. A polarization resistance of 3.66 mOhm cm 2 at 900…”

Section: Resultsmentioning

confidence: 99%

Electronic and Ionic Transport in Ce_0.8Pr_xTb_0.2−xO_2−δand Evaluation of Performance as Oxygen Permeation Membranes

Chatzichristodoulou

Hendriksen

2012

J. Electrochem. Soc.

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“…In order to increase the ionic conductivity, the activation energy should be minimum for oxygen diffusion, which can be achieved with the selection of proper dopants. Among rare earth elements gadolinium and samarium doped ceria have been generally used due to these lattice parameters almost equal to undoped ceria which have high solubility in ceria [2]. Their substitution creates very small strain in the lattice which reduces the activation energy for diffusion of oxide ions [3,4].…”

Section: Introductionmentioning

confidence: 99%

Electrical Properties of Sr2+ and Gd3+ Codoped Ceria Electrolyte System for LT-SOFC

Koteswararao¹,

Suresh²,

Varalaxmi³

et al. 2018

Asian J. Chem.

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This paper reports the effect of Sr 2+ addition on electrical properties of Ce0.8Gd0.2O2-δ (GDC) electrolyte for low temperature solid oxide fuel cell application. The Sr 2+ (0, 0.5, 1 and 2 mol %) doped GDC solid electrolytes have been prepared by solid state method. The sintered densities of the samples are around 95 %. Among all the compositions, the highest ionic conductivity is observed in the GDC sample with 0.5 mol % Sr addition. Nyquist plots resulted in multiple redoxation process such as grain and grain boundary conductions to the final conductivity. Estimated blocking factor is lower for the GDC electrolyte with 0.5 mol % Sr 2+ , indicating that Sr 2+ addition promoted grain boundary conduction. Activation energies were calculated from Arrhenius plot and are found in the range of 0.80 to 1.25 eV, indicating oxygen ion conduction in the doped GDC electrolyte system of samples.

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“…8,9 Furthermore, the thermal expansion coefficients of Ln 2 NiO 4 -based materials are comparable to those of doped ceria and lanthanum gallate, which are well-known solid electrolytes. 6,[10][11][12][13] The cathode of SOFCs should have high oxygen reduction kinetics, which, in turn, should depend on the oxide ionic diffusion and oxygen surface exchange rate. 14 Although the oxygen self-diffusion coefficient of Ln 2 NiO 4+¤ has been reported by various researchers, there are discrepancies in the reported values.…”

Section: Introductionmentioning

confidence: 99%

Relationship between Local Structure and Oxide Ionic Diffusion of Nd2NiO4+^|^delta; with K2NiF4 Structure

et al. 2014

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The relationship between the local structure and oxide ionic conduction of Nd 2 NiO 4+δ possessing the K 2 NiF 4 structure was investigated. Various oxygen nonstoichiometry samples of Nd 2 NiO 4+δ prepared with different annealing oxygen partial pressures were examined. The local structure related to oxide ionic conduction was determined by the Nd K-edge extended X-ray absorption fine structure. The oxide ionic conductivity and surface exchange coefficient were estimated using electronic conductivity relaxation methods. The activation energy for the oxide ionic conductivity was found to have a direct correlation to the surface exchange coefficient. The bottleneck size for oxide ion conduction was strongly correlated to the oxide ionic conduction of interstitial oxygen and the oxygen surface exchange rate.

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Cited by 458 publications

References 35 publications

Electronic and Ionic Transport in Ce_0.8Pr_xTb_0.2−xO_2−δand Evaluation of Performance as Oxygen Permeation Membranes

Electronic and Ionic Transport in Ce_0.8Pr_xTb_0.2−xO_2−δand Evaluation of Performance as Oxygen Permeation Membranes

Electrical Properties of Sr2+ and Gd3+ Codoped Ceria Electrolyte System for LT-SOFC

Relationship between Local Structure and Oxide Ionic Diffusion of Nd2NiO4+^|^delta; with K2NiF4 Structure

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Cited by 458 publications

References 35 publications

Electronic and Ionic Transport in Ce0.8PrxTb0.2−xO2−δand Evaluation of Performance as Oxygen Permeation Membranes

Electronic and Ionic Transport in Ce0.8PrxTb0.2−xO2−δand Evaluation of Performance as Oxygen Permeation Membranes

Electrical Properties of Sr2+ and Gd3+ Codoped Ceria Electrolyte System for LT-SOFC

Relationship between Local Structure and Oxide Ionic Diffusion of Nd2NiO4+^|^delta; with K2NiF4 Structure

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Product

Resources

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Electronic and Ionic Transport in Ce_0.8Pr_xTb_0.2−xO_2−δand Evaluation of Performance as Oxygen Permeation Membranes

Electronic and Ionic Transport in Ce_0.8Pr_xTb_0.2−xO_2−δand Evaluation of Performance as Oxygen Permeation Membranes