Anodic polarization creates an electrocatalytically active Ni anode/electrolyte interface and mitigates the coarsening of Ni phase in SOFC

Abstract

An intimate Ni anode/electrolyte interface is vital for the performance and operating stability of solid oxide fuel cells, while the interface is greatly influenced under anodic polarization conditions. Here for the first time Ni anodes are directly assembled on 8 mol% Y2O3-stabilized ZrO2 (YSZ) electrolyte without high temperature sintering process, and the interface formation between Ni anode and YSZ electrolyte is studied at varied anodic polarization currents at 800 °C. The results show that an intimate anode/electrolyte interface can be created by applying anodic polarization current, leading to remarkably enhanced electrocatalytic activity and operating stability. The major reason of enhanced stability is ascribed to the mitigated microstructure coarsening of Ni anodes due to the strong interfacial bonding induced by the anodic polarization. The present findings shed lights on rational design of Ni based anode/electrolyte interface by tuning the anodic polarization.