The performance of membraneless microfluidic fuel cells can be predominated by the air‐breathing cathode, making it essential to understand the effect of nano‐ and micro‐structures on the oxygen transport and reaction. For the first time, pore‐scale Lattice Boltzmann Method (LBM) models have been developed to simulate the oxygen transport in air-breathing cathode based on reconstructed structures. The underneath electrolyte microchannel is also considered. A modified LBM model is used to handle the numerical instability caused by large diffusivity ratio (104) between the gaseous and dissolved oxygen. The oxygen is found to penetrate into the microchannel. The distribution of oxygen and reaction rate suggest the nano‐ and micro‐structures can affect the oxygen transport and electrochemical reaction.
Keywords Microfluidic fuel cell, Air‐breathing cathode, Pore‐scale modeling, Lattice Boltzmann method, Mass transport