Effect of cathode gas flow patterns on performance of micro direct methanol fuel cell

In this paper, an active oxygen-supplying micro direct methanol fuel cell (μDMFC) and an air-breathing μDMFC were designed, fabricated and tested. Stainless steel plates with the thickness of 200μm were chosen to fabricate the current collectors by the micro stamping. The 5-layered membrane electrode assembly (MEA) was fabricated by the catalyst coated membrane (CCM) method. The polymethyl methacrylate (PMMA) plates were manufactured into fixer plates with the heat-resistant treatment. Silicon rubber gaskets were employed to keep the cells from liquid leakage, which relieves the fixing pressure during clamping and prevents short circuit. The effects of different methanol concentrations and supply velocities on the performance of both μDMFCs were studied. The active oxygen-supplying μDMFC exhibited a maximum output power density of 65.66mW/cm² at 40°C, while the air-breathing μDMFC provided a maximum output power density of 27.11mW/cm² at 20°C. And experiments were carried out to compare the effects of the two cathode gas flow patterns on cell performance. The results revealed that the active oxygen-supplying μDMFC exhibits higher performance than the air-breathing μDMFC at the cost of more complex system structure and parasitic power consumption.