Nano-fabrication of a high-performance LaNiO3 cathode for solid oxide fuel cells using an electrochemical route

Abstract

The cost-effective fabrication of nanostructured cathodes for solid oxide fuel cells (SOFCs) that catalyze the oxygen reduction reaction effectively is a milestone to be achieved. Infiltration being the conventional method for the fabrication of nanostructured SOFC cathodes requires many infiltration and calcination cycles due to the low catalyst loading per infiltration cycle. Chemically assisted electrodeposition (CAED), a new means of fabricating nanostructured SOFC cathodes in a single loading step, provides the advantage of the simultaneous deposition of multiple cations while using dilute aqueous solutions of readily available salts. In this study, CAED is demonstrated by fabricating a cobalt-free LaNiO3/GDC composite cathode. The LaNiO3/GDC composite cathode prepared by CAED exhibits superior electrochemical properties compared to LaNiO3/GDC composite cathodes fabricated by sintering or self-assembly (a recently introduced low-temperature SOFC cathode fabrication method) approaches. An anode-supported SOFC with a LaNiO3/GDC composite cathode fabricated by CAED shows a high power density of 974 mW cm−2 at an intermediate operating temperature of 750 °C. Low-temperature nano-fabrication by CAED, producing a cathode with a high surface area while avoiding the formation of insulating phases, is believed to play an important role in achieving better SOFC performance.