Electrical Properties of Co-Doped Ceria Electrolyte Ce_0.8-xGd_0.2Sr_xO_2-δ(0.0 ≤ x ≤ 0.1)

Abstract

Effects of strontium doping on electrical properties of gadolinium-doped ceria were investigated. The Ce 0.8-x Gd 0.2 Sr x O 2- (0.0 x 0.1) compositions were prepared by sol-gel method and sintered at 1300 C for 8 h, the bulk densities were over 93% of theoretical density. These results were consistent with scanning electron microscope. The crystallite size of these materials was determined using the X-ray powder diffractometer and the sizes range from 19.4 nm to 24.4 nm. From the experimental results, it was observed that the composition Ce 0.8-x Gd 0.2 Sr x O 2- (x = 0.02) exhibits higher conductivity (23.6 10 -3 S cm -1 ) and minimum activation energy (0.83 eV) at 700 C. This composition is thus a potential candidate for use as electrolyte applications in intermediate temperature solid oxide fuel cells.