Effective transport properties of 3D multi-component microstructures with interface resistance

Abstract

A three-dimensional image analysis tool has been developed to compute the effective conductivity of a particulate composite made of pores (material 0) and two materials (1) and (2). Three types of resistances are considered: the two resistances between materials (1)–(1) and (2)–(2) and the charge transfer resistance at the interface between materials (1) and (2). The numerical tool uses voxelised 3D numerical microstructures generated by discrete element simulations to mimic the particulate nature of the tested material. The method is validated by comparing its results to a resistance network model that incorporates interface resistance. The validation is conducted for both homogeneous and composite materials. Our tool has the advantage, compared with a resistance-network model, of allowing 3D tomography images to be treated. The method is applied to a microstructure typical of a composite Solid Oxide Fuel Cell cathode, however it is general enough to be a versatile tool for computing effective transport properties of any composite material where interface properties must be taken into account.