Development and fabrication of passive DMFCs

The present work developed direct methanol fuel cells (DMFC) which have passive methanol feeding designs integrated. The design eliminated any mechanical parts in the DMFC and both methanol feeding and carbon dioxide exclusion on the anode side are accomplished through the special designs of the fluidic channels on current collecting plate on anode side. The anode of this DMFC is not submerged into liquid methanol. Therefore, the crossover of methanol and water from anode side to cathode side is significantly reduced, which relieves cathode water flooding dramatically. The cathode is designed to have air-breathing function that draws air by natural convection mass transfer method. A stable and lasting power output of 1.5 (mW/cm²) at 0.35 (V) was obtained for a single cell which operates at room temperature and completely eliminated with parasitic parts. It is expected that the methanol delivery and control in a passive mode through the presently developed special design of flow channels will greatly promote the development of cost-effective DMFCs with easy maintenance and high reliability.