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

Abstract

Codoping is used to enhance the ionic conductivity of ceria-based electrolytes. Sm3+ and Nd3+ 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 SmxNdxCe1−2xO2−δ solid solutions is measured using electrochemical impedance spectroscopy. It was observed that for Sm0.075Nd0.075Ce0.85O2−δ, the grain ionic conductivity was 14.0×10−3Scm−1 at 550°C, which makes it one of the most promising ceria-based electrolytes for intermediate temperature solid oxide fuel cells.