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

摘要

One of the critical obstacles for commercialization of solid oxide fuel cells (SOFCs) tech-nology 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 degrees C, such spray-coated cathodes show a typical interfacial polarization resistance of similar to 0.059 Omega cm(2), much lower than that of similar to 0.10 Omega cm(2) 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 degrees C using wet H-2 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.

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