Structure—Properties—Performance: Modelling a Solid Oxide Fuel Cell with Infiltrated Electrodes

The microstructure of a solid oxide fuel cell (SOFC) electrode has a direct impact on its transport and kinetic properties, which in turn control electrode and cell performance. This study presents models and simulations for SOFC performance that use previously published models to describe the connection between electrode microstructure and key properties such as effective conductivity, three phase boundary density, effective diffusivity, and permeability. These effective properties are then used in a multiphysics model that solves the coupled set of differential equations that describe the working of a SOFC for a given set of operating conditions and model parameters. The results presented strongly suggest that using infiltrated electrodes for both the air and fuel electrodes, instead of conventional composite sintered-powder based electrodes, leads to substantially higher performance as measured by high current density at high cell potentials and high fuel utilization. The cell performance curves are supplemented with sensitivity and parametric analyses to examine the impact of varying experimentally controllable electrode microstructural parameters on cell performance.