Quantitative Evaluation of Transport Properties of SOFC Porous Anode by Random Walk Process

Abstract

Microstructural properties of an SOFC anode, such as tortuosity, surface-to-volume ratio and permeability, are quantitatively evaluated using three-dimensional data obtained by a system consisting of a focused ion beam and scanning electron microscope, FIB-SEM. A method employed to evaluate these properties is based on a random walk process in which the diffusion of imaginary particles is considered. In addition, the connectivities of three phases, i.e., the Ni, YSZ and pore phases are also analyzed. The relationships among these properties and their effects on transport phenomena in a porous anode are discussed. It is revealed that the low connectivity and complex microstructural configuration of the porous anode result in large tortuosities in the Ni and YSZ phases, respectively.