Resistor networks for the simulation of voxelized MIEC electrodes: Coupling transport and electrocatalytic processes

Abstract

This study presents a generalized resistor-network framework for simulating voxelized mixed ionic–electronic conductor (MIEC) electrodes, incorporating an explicit gas-phase diffusion network. This work presents a microstructure-resolved formulation that maps electronic, ionic, and gas-phase transport processes onto voxel-level resistor networks, enabling consistent coupling of the relevant physical mechanisms.The methodology employs synthetically generated voxelized geometries to solve three interconnected resistor networks governed by Ohm’s law (for electronic and ionic transport) and Fick’s law (for gaseous diffusion), linked through resistors representing the electrocatalytic interface. Validation studies demonstrate the model’s capability to capture microstructure-dependent transport and rate-limiting behavior at the active sites, yielding consistent concentration profiles, potential distributions, and derived quantities such as effective tortuosity. Good agreement with experimental data supports the reliability of the framework.This voxel-based approach provides a conceptually transparent and easily applicable tool for realistic modeling of porous MIEC electrodes, directly compatible with 3D tomographic datasets, and offers new opportunities for structure–performance analysis and optimization of solid oxide fuel cell (SOFC) electrodes.