Understanding transport phenomena in electrochemical energy devices via X-ray nano CT

X-Ray Microscopy Conference 2016

Tjaden, B.^1 ; Lane, J.^2 ; Brett, D.J.L.^1 ; Shearing, P.R.^1

Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, WC1E 7JE, United Kingdom^1

Praxair Inc., 175 E. Park Dr., Tonawanda

NY

14150, United States^2

关键词: Calculation algorithms;    Complex microstructures;    Diffusive mass transport;    Electrochemical devices;    Electrochemical energy;    Micro-structural characteristics;    Oxygen transport membranes;    Transport phenomena;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/849/1/012018/pdf
DOI  :  10.1088/1742-6596/849/1/012018

来源: IOP

【 摘 要 】

Porous support layers in electrochemical devices ensure mechanical stability of membrane assemblies such as solid oxide fuel cells and oxygen transport membranes (OTMs). At the same time, porous layers affect diffusive mass transport of gaseous reactants and contribute to performance losses at high fuel utilisation and conversion ratios. Microstructural characteristics are vital to calculate mass transport phenomena, where tortuosity remains notoriously difficult to determine. Here, the tortuosity of tubular porous support layers of OTMs is evaluated via high resolution X-ray nano computed tomography. The high resolution reveals the complex microstructure of the samples to then execute a selection of image-based tortuosity calculation algorithms. Visible differences between geometric and flux-based algorithms are observed and have thus to be applied with caution.