Model-guided design of a high performance and durability Ni nanofiber/ceria matrix solid oxide fuel cell electrode
An electrochemical model is developed to predict the performance of ceria-based SOFC anode from its microstructure. A fiber–matrix structure is then synthesized accordingly that shows exception performance and stability. [Display omitted] Mixed ionic electronic conductors (MIECs) have attracted incr...
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Published in: | Journal of energy chemistry 2021-05, Vol.56, p.98-112 |
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Main Authors: | , , , , , , , , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | An electrochemical model is developed to predict the performance of ceria-based
SOFC anode from its microstructure. A fiber–matrix structure is then synthesized accordingly that shows exception performance and stability.
[Display omitted]
Mixed ionic electronic conductors (MIECs) have attracted increasing attention as anode materials for solid oxide fuel cells (SOFCs) and they hold great promise for lowering the operation temperature of SOFCs. However, there has been a lack of understanding of the performance-limiting factors and guidelines for rational design of composite metal-MIEC electrodes. Using a newly-developed approach based on 3D-tomography and electrochemical impedance spectroscopy, here for the first time we quantify the contribution of the dual-phase boundary (DPB) relative to the three-phase boundary (TPB) reaction pathway on real MIEC electrodes. A new design strategy is developed for Ni/gadolinium doped ceria (CGO) electrodes (a typical MIEC electrode) based on the quantitative analyses and a novel Ni/CGO fiber–matrix structure is proposed and fabricated by combining electrospinning and tape-casting methods using commercial powders. With only 11.5 vol% nickel, the designer Ni/CGO fiber–matrix electrode shows 32% and 67% lower polarization resistance than a nano-Ni impregnated CGO scaffold electrode and conventional cermet electrode respectively. The results in this paper demonstrate quantitatively using real electrode structures that enhancing DPB and hydrogen kinetics are more efficient strategies to enhance electrode performance than simply increasing TPB. |
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ISSN: | 2095-4956 |
DOI: | 10.1016/j.jechem.2020.07.026 |