Enhancing DMFC Performance: Addressing CO₂ Bubble Formation and Methanol Delivery Issues

Direct Methanol Fuel Cells (DMFCs) offer substantial promise for portable power applications due to their high energy density and operational simplicity. Despite their potential, optimizing DMFC performance remains a significant challenge, particularly concerning mass transport at the anode. CO₂ bubble formation at the anode poses a major impediment to efficient mass transport and overall cell performance. Bubbles can block active catalytic sites, hinder methanol access, and increase the ohmic resistance of the cell. State-of-the-art computational and experimental techniques have been developed to study CO₂ bubble dynamics. Advanced imaging techniques, such as high-resolution microscopy and synchrotron X-ray tomography, have provided detailed visualizations of bubble behavior within the anode structure. Meanwhile, mechanistic modelling and multi-scale simulations have offered deeper insights into the interactions between bubble dynamics and mass transport processes. This paper also highlights innovative strategies to mitigate the adverse effects of CO₂ bubbles, including the optimization of flow field designs, development of novel catalyst supports, and the use of surface treatments to enhance bubble detachment and transport. Looking towards the future, we propose the development of a mist feed anode system as a promising direction to further improve methanol delivery and reduce CO₂ bubble formation. The mist feed system aims to create a more uniform distribution of methanol at the anode, enhancing its availability while minimizing local oversaturation and subsequent bubble formation.