Effect of carbonates addition on Ce0.80Gd0.20O1.90 (GDC) nanorods prepared by wet chemical route for LT-SOFCs

Abstract

Ce0.80Gd0.20O1.90 (GDC) nanorods have been prepared using a wet chemical precipitation synthesis route. Binary mixture of Li2CO3 and Na2CO3 has been introduced in the GDC nanorods (GDC nanocomposites) to stabilize them at a higher temperature (650 °C) for application in low temperature solid oxide fuel cells (LT-SOFCs). Different weight ratios of carbonate have been added to see the effect on phase formation, morphology and the electrical conductivity. Single phase formation has been confirmed by X-ray diffraction. Carbonates act as a grain growth inhibitor and increase the stability of nanorods due to low sintering temperature 650 °C. Morphology reveals that the GDC nanorods in the matrix are present with a high aspect ratio. Conductivity anomalous has been observed in all the compositions at a particular temperature. This is due to a superionic transition at the interfaces formed between the ceria and the carbonate phase. Composition with 30 wt% of carbonate shows the highest conductivity, 2.7 × 10−1 at 500 °C with an activation energy 0.21 eV. © 2016 Hydrogen Energy Publications LLC