An oxygen reduction reaction active and durable SOFC cathode/electrolyte interface achieved via a cost-effective spray-coating

Abstract One of the critical obstacles for commercialization of solid oxide fuel cells (SOFCs) technology is to develop efficient interfaces between cathode and electrolyte that enable high activity toward oxygen reduction reaction (ORR) while maintain long-term durability. Here, we report a cost-effective spray-coating process that applied in the building of an ORR active and durable cathode/electrolyte interface. When tested at 750 °C, such spray-coated cathodes show a typical interfacial polarization resistance of ~0.059 Ωcm2, much lower than that of ~0.10 Ωcm2 for screen-printed cathodes. Detailed distribution of relaxation time analyses of the impedance spectra over time indicates that the capability of mass transfer and surface exchange process in the spray-coated cathode/electrolyte interface has been enhanced and maintained in the testing periods of ~100 h. As a result, a Ni-based anode supported cell with thin electrolyte and spray-coated cathodes shows an excellent peak power density of 1.012 Wcm−2, much higher than that of 0.712 Wcm−2 for cells with screen-printed cathodes, when tested at 750 °C using wet H2 as fuel and ambient air as oxidant. It is demonstrated that ORR activity and durability of the SOFC cathodes can be dramatically enhanced via a cost-effective spray-coating process.