Direct methanol fuel cells (DMFCs) exhibit some advantages such as easy storage and transportation of fuel, and high specific energy density, compared to lithium batteries. However, there are still many problems in the widespread use of passive DMFC as lithium batteries.
One of the problems is the rapid removal of carbon dioxide at the anode to enhance the performance of passive DMFC. Carbon dioxide removal depends on the structure of the anode flow field (AFF), MEA and even operating conditions. Most of the efforts to effectively remove carbon dioxide have focused on reducing the bubble resistance of CO2 by improving the structure and shape of AFF.
However, efforts to reduce the negative impact of CO2 gas in MEA have not reached complete separation of two-phase flow in the anode gas diffusion layer (AGDL).
Jon Song Hyok, a researcher at the Faculty of Chemical Engineering, has proposed a new anode gas diffusion layer (AGDL) structure that can overcome the effects of two-phase flow in the MEA, the core of passive DMFC.
Using the anode carbon paper hydrophobically treated with 50wt.% PTFE loading, carbon dioxide is released to the lateral venting channels and methanol is allowed to be fed through a hole in the middle of the carbon paper.
Compared to the conventional DMFC, this improved AGDL provided a stable operating environment by separating the two-phase flow inside the cell and showed good performance with the maximum power density 17.3mW/cm2 at 12.0M methanol concentration.
If more information is needed, please refer to his paper “Efficient CO2 Removal by Improving Diffusion Layer Structure in Methanol Fuel Cells” in “Proceedings of KUTIC-2025”.