Towards the Microstructural Optimisation of Solid Oxide Fuel Cell Electrodes
One-dimensional numerical simulation and microstructural analysis of solid oxide fuel cell (SOFC) electrodes are carried out to investigate the effect of the characteristic length scale of the porous electrodes on the performance. The sensitivity of the current density is analysed over a wide range of triple-phase boundary (TPB) density and mean-pore size, which affect the electrochemical reaction and transport. Comparison between conventional electrodes and nano-particle infiltrated electrodes reveals that reducing characteristic length scale in the conventional electrodes helps improve the electrode performance by reducing the reaction resistance; however, introducing nano particles into the electrodes is expected to be more effective as it has a potential to increase the TPB density whilst keeping better gaseous transport through the electrodes. The three-dimensional microstructures of both types of electrodes are obtained with focused ion beam scanning electron microscopy and provide useful microstructural information that supports the numerical analysis.