A Dynamic Multi-Scale Model for Solid Oxide Cells Validated on Local Current Measurements: Impact of Global Cell Operation on the Electrodes Reaction Mechanisms

International audienceA dynamic physically based model has been developed to unravel the relationships between the overall Solid Oxide Cells response and the reaction mechanisms taking place in the electrodes. This tool combines modules at three different length-scales: electrode microstructures, active functional layers, and single repeat unit. It allows computing the cell polarization together with the distribution of the local current densities, overpotentials, and gas composition. It has been shown that the synthetic electrode model reproduces accurately the real microstructure, which has been checked by comparison with 3D reconstructions. The microscale electrode models have been validated using polarization curves and impedance spectra measured in symmetrical cells. Finally, tests were conducted at different temperatures and inlet flow rates to validate the integrated multiscale approach. For this purpose, a special setup was developed to measure the local current densities in standard cells. A good agreement was found between the experimental and simulated data