Design and fabrication of a silicon-based direct methanol fuel cell with a new cathode spoke structure

In this paper, a self-breathing micro direct methanol fuel cell (μDMFC) featuring a new cathode current collector with a spoke configuration is presented to improve cell performance. Simulation results show that the new spoke structure can effectively increase the efficiency of oxygen mass transport and exhibit higher pressure than the conventional perforated structure. The water transfer to the proton exchange membrane (PEM) is promoted to reduce the PEM resistance with the increase in the membrane water content. Additionally, the effects of the spoke blades on performance were evaluated to determine the optimal cathode structure. The self-breathing μDMFCs with conventional and new cathode structures were fabricated using silicon-based micro-electromechanical system (MEMS) technologies and tested at room temperature with 1 M methanol solution. The experimental results revealed that the spoke cathode structure exhibits significantly higher performance than the conventional structure, showing a substantial 30% increase in peak power density.