Promotion of SOFC Cathode Performance and Durability by the Addition of Mixed Conducting Praseodymium Oxides

Abstract

Solid oxide fuel cells (SOFCs) convert the chemical energy from a fuel into electricity at elevated temperatures with a high efficiency and in an environment-friendly manner. The high polarization resistance of the oxygen electrode, corresponding to a low electrode activity and a low cell performance, can be reduced by introducing various catalysts to the electrode. In this work, praseodymium oxides are introduced into the LSCF cathode by infiltration. In addition, the barrier layer, Gd0.2Ce0.8O1.9, was replaced with Pr0.1Gd0.1Ce0.8O1.9. The increase of power density at 0.8 V is approximately 0.2 W/cm2 by applying a PGCO buffer, 0.13 W/cm2 by infiltration, and 0.34 W/cm2 through implementation of both. Current-voltage plots and electrochemical impedance spectroscopy were used to examine the electrochemical performance of SOFCs. The distribution of relaxation time was used to analyze the mechanism for which the polarization resistance was decreased and was attributed to the mixed conduction nature in PrOx.