Role of mixed conducting Pr0.1Gd0.1Ce0.8O1.9-δ barrier layer on the promotion of SOFC performance

Abstract

The cathode activity in a solid oxide fuel cell can be promoted by introducing various catalysts to reduce its polarization resistance towards oxygen reduction, and thus improve cell performance. In this work, the La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) cathode surface is modified by the infiltration of Pr6O11 and the power density at 0.8 V and 750 °C is improved by 21%. Moreover, by replacing the traditional barrier layer Gd0.2Ce0.8O1.9 with mixed conducting Pr0.1Gd0.1Ce0.8O1.9 (PGCO), the power density increases by 38%. The ohmic resistance is dramatically reduced by applying the PGCO interlayer. The distribution of relaxation time was used to analyze the mechanism for which the polarization resistance was decreased, attributing to the mixed conduction nature in PrOx. An increase of power density, ∼0.358 W/cm2 (71%) at 0.8 V, is achieved with the implementation of both surface modification and buffer layer engineering.