Microstructural Modeling and Effective Properties of Infiltrated SOFC Electrodes

A modeling framework for the microstructural modeling of infiltrated SOFC electrodes is presented. The model numerically reconstructs infiltrated electrodes through a sedimentation algorithm for the backbone generation and a novel Monte Carlo packing algorithm for the random infiltration. Effective properties are evaluated by means of Monte Carlo geometric analysis and finite volume method as a function of the loading and of the particle size of infiltrated particles. Infiltration into ion-conducting and composite backbones is analyzed in this study. Simulations show that the infiltration can lead to an increase in TPB density of about two orders of magnitude if compared with conventional composite electrodes. In addition, infiltration into monocomponent backbones can lead to a TPB density about twice the TPB achievable when infiltrating composite backbones. On the other hand, a critical loading of nanoparticles must be reached in monocomponent backbones while in a composite backbone the infiltration is always beneficial.