A Coupled Physics and Electrochemical Reaction Model for Porous Microstructural Electrodes of Solid Oxide Electrolysis Cell

摘要

A coupled physics and electrochemical reaction model was developed to evaluate the performance of solid oxide electrolysis cell (SOEC) porous electrode microstructures. The influence of geometric and transport properties on the performance of porous SOEC electrode microstructures is investigated. The detailed micro-scale model was developed in OpenFOAM (Open Field Operation and Manipulation), which is a free open-source computational fluid dynamic (CFD) software package. The sample electrode microstructures investigated in this work were obtained from both experimental reconstruction and synthetic numerical manufacturing methods. The experimental electrode sample was reconstructed using a focused ion beam-scanning electron microscopy (FIB-SEM) technique. An in-house computational technique, written in C++ language, was used to synthetically manufacture the electrode microstructures and was based on the drop-and-roll method of particle placement. The geometric and physical input parameters (e.g. particle-size distribution, particle-to-particle overlap, and porosity) for the numerical model were approximated from the FIB-SEM based experimental reconstruction model. The resulting simulated samples from both methods were then converted into numerical meshes for detailed micro-scale model analysis. Inference on the design and optimization process of SOEC electrodes is given from evaluating the relationship between the electrode voltage and current density for various compositions of initial manufacturing parameters.