Higher ionic conductive ceria-based electrolytes for solid oxide fuel cells

摘要

Codoping is used to enhance the ionic conductivity of ceria-based electrolytes. Sm~(3+) and Nd~(3+) were selected as codopants to promote low migration energy paths for oxygen vacancy diffusion, thereby increasing the ionic conductivity. Moreover, the use of codopants also increases the pre-exponential factor in the Arrhenius relationship, thus further improving the ionic conductivity. The ionic conductivity of Sm_xNd_xCe_(1－2x)O_(2－δ) solid solutions is measured using electrochemical impedance spectroscopy. It was observed that for Sm_(0.075)Nd_(0.075)Ce_(0.85)O_(2-δ), the grain ionic conductivity was 14.0 × 10~(-3) S cm~(-1) at 550 ℃, which makes it one of the most promising ceria-based electrolytes for intermediate temperature solid oxide fuel cells.