Validation of a physically-based solid oxide fuel cell anode model combining 3D tomography and impedance spectroscopy. (21st December 2016)

• Record Type: Journal Article
• Authors: Bertei, A.; Ruiz-Trejo, E.; Tariq, F.; Yufit, V.; Atkinson, A.; Brandon, N.P.
• Is Part Of: International journal of hydrogen energy. Volume 41:Number 47(2016)
• Page Start: 22381
• Page End: 22393
• Publication Date: 2016-12-21
• Subjects: Physically-based modelling -- Validation -- Electrochemical impedance spectroscopy -- Scandia-stabilized zirconia -- Charge-transfer -- Anode; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2016.09.100
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: This study presents a physically-based model for the simulation of impedance spectra in solid oxide fuel cell (SOFC) composite anodes. The model takes into account the charge transport and the charge-transfer reaction at the three-phase boundary distributed along the anode thickness, as well as the phenomena at the electrode/electrolyte interface and the multicomponent gas diffusion in the test rig. The model is calibrated with experimental impedance spectra of cermet anodes made of nickel and scandia-stabilized zirconia and satisfactorily validated in electrodes with different microstructural properties, quantified through focused ion beam SEM tomography. Besides providing the material-specific kinetic parameters of the electrochemical hydrogen oxidation, this study shows that the correlation between electrode microstructure and electrochemical performance can be successfully addressed by combining physically-based modelling, impedance spectroscopy and 3D tomography. This approach overcomes the limits of phenomenological equivalent circuits and is suitable for the interpretation of experimental data and for the optimisation of the electrode microstructure. Graphical abstract: Highlights: A physically-based model is developed to simulate impedance of SOFC anodes. Microstructural parameters are obtained with FIB-SEM in different anodes. Fitted kinetic properties, validated in different microstructures and literature. The contribution of anode microstructure to performance is successfully quantified. Models must be validated with impedance data in samples with different microstructure.