Development and characterization of a novel air-breathing micro direct methanol fuel cell stack for portable applications

An air-breathing 10-cell micro direct methanol fuel cell (μDMFC) stack with four anode feeding patterns is designed, fabricated and tested. For a better understanding of the operational characteristics of both the single cell and the stack, a two-dimensional numerical model is established and calculated. Employing micro-stamping technology, the current collectors of each single cell are microfabricated on the stainless steel plate with a thickness of 300 μm. The single μDMFC is first tested under various operating parameters. On the basis of the simulation and experimental observation of the single cell performance, the μDMFC stack performance is thoroughly analyzed with different anode feeding patterns. The results indicate that the μDMFC stack with pattern B can ensure the uniform performance of each single cell and generate the highest power output. With pattern B, further experiments are carried out to investigate the influence of the anode flow rate on the stack performance. As a result, the μDMFC stack achieves the best performance with the maximum power density of about 24.75 mW cm^-2 at 5.0 ml min ^-1. Finally, the stack is successfully applied to two electronic devices of different rated power.