Er and Gd Co-Doped Ceria-Based Electrolyte Materials for IT-SOFCs Prepared by the Cellulose-Templating Method

Abstract

Ce0.9-x Gd0.1Er (x) O1.9-x/2 (0 a parts per thousand currency sign x a parts per thousand currency sign 0.1) (EGDC) powders were successfully synthesized with a fast and facile cellulose-templating method for the first time and characterized by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The samples were calcined at a relatively low calcination temperature of 773 K (500 A degrees C). The sintering behavior of the calcined EGDC powders was also investigated at 1673 K (1400 A degrees C) for 6 hours. Calcined Ce0.9-x Gd0.1Er (x) O1.9-x/2 (0 a parts per thousand currency sign x a parts per thousand currency sign 0.1) powders and sintered Ce0.9-x Gd0.1Er (x) O1.9-x/2 (0 a parts per thousand currency sign x a parts per thousand currency sign 0.1) pellets crystallized in the cubic fluorite structure. It was found that the relative densities of the sintered EGDC pellets were over 95 pct for all the Er contents studied. Moreover, the effect of Er content on the ionic conductivity of the gadolinium-doped ceria (GDC, Ce0.9Gd0.1O1.90) was investigated. The highest ionic conductivity value was found to be 3.57 x 10(-2) S cm(-1) at 1073 K (800 A degrees C) for the sintered Ce0.82Gd0.1Er0.08O1.91 at 1673 K (1400 A degrees C) for 6 hours.