Evaluation of the Influence of Gadolinium Doped Ceria Particle Size on the Electrochemical Performance and Microstructure of Nickel-Gadolinium Doped Ceria Anodes

摘要

Composite anodes consisting of nickel-gadolinium doped ceria (Ni-GDC) cermet increasingly gain a lot of attention as they have potential to be a beneficial solution for the intermediate temperature solid oxide fuel cells. In this paper, the influence of the initial microstructure of Ni-GDC anode on the electrochemical performance and its deterioration in 100-h operation are investigated. The initial microstructure of investigated anodes is determined by the different aspect ratios and sizes of GDC powder used in the fabrication, but all anodes had the same initial chemical compositions of NiO:GDC=60:40 vol%. The microstructure of the fabricated anodes has been investigated by focused ion beam - scanning electron microscopy tomography (FIB-SEM) and quantitatively evaluated to deliver the factors expressing the microstructural characteristics, especially important ones for the electrochemical performance: Triple-Phase-Boundary (TPB) density, Double-Phase-Boundary (DPB) density and tortuosity factor. From the experimentation, contribution of the Ni-GDC microstructure to the anode electrochemical performance is discussed.