Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1290399 | Journal of Power Sources | 2008 | 6 Pages |
Abstract
This study examines the effect of calcium oxide (CaO) addition to Ce0.9Gd0.1O1.95 (gadolinia-doped ceria, GDC) containing 500 ppm SiO2 on grain-interior and grain-boundary conduction. The GDC can be used as a solid electrolyte for intermediate and low-temperature solid oxide fuel cells. Doping with â¥2 mol% CaO results in a decrease in apparent grain-boundary resistivity at 300 °C from 746.7 kΩ cm to 2.8-3.5 kΩ cm. The total resistivity exhibits a minimum at 2 mol% CaO. Further increase in CaO concentration to 10 mol% results in an increase in grain-interior resistivity from 3.1 to 40 kΩ cm. Although most of the CaO is incorporated into the GDC lattice, a small amount of CaO scavenges the intergranular siliceous phase, which leads to a significant increase in grain-boundary conduction. The increase in grain-interior resistivity at high CaO concentration is attributed to defect association between VO and CaCeâ³.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
Pyeong-Seok Cho, Sung Bo Lee, Yoon Ho Cho, Doh-Yeon Kim, Hyun-Min Park, Jong-Heun Lee,