Enhancing the Performance of Metal-Supported Solid Oxide Fuel Cells via Infiltration with an Aqueous Solution of Metal Nitrate Salts

The infiltration technique is a cost-effective method to develop nanostructured electrodes that can accelerate sluggish oxygen reduction reaction (ORR) and enhance the electrochemical performance of solid oxide fuel cells (SOFCs) at intermediate temperatures (600-800 °C). For metal-supported SOFCs, identifying a highly efficient ORR catalyst is an ongoing challenge due to lower temperature operation. In this work, nanostructured praseodymium oxide (PrO_<i>x</i>) and multiphase heterostructures containing perovskites with the nominal composition of Nd_0.6Sr_0.4CoO_3-δ (NSC), SrCO_3, and CoO have been developed via infiltration into the symmetric metal-supported backbone as binary layer composite, and their electrochemical performance has been investigated. The composite demonstrates enhanced electrochemical performance at various temperatures achieving the lowest polarization resistance (<i>R</i>_p) of 0.05 Ω cm² at 700 °C compared to multiphase NSC alone (0.1 Ω cm²) under similar conditions. A distribution function of relaxation time (DFRT) analysis using impedance spectroscopy genetic program (ISGP) was carried out to study different electrochemical processes. PrO_<i>x</i> significantly improves the processes involved in the ORR. The full cell performance of the composite electrode achieves a peak power density (PPD) of 329 mW·cm^-2 at 700 °C in 3%H₂O/H₂ as fuel.