Operational and structural aspects of a vapor-feed semi-passive direct methanol fuel cell supplied with concentrated methanol

Direct methanol fuel cell (DMFC) has great potential to replace the traditional battery in the field of portable power sources. This study investigates the operational and structural aspects of a vapor-feed semi-passive DMFC supplied with concentrated methanol. The effectiveness of using vaporous methanol to improve the cell performance is experimentally validated. Results indicate that there exits an optimal value of methanol concentration that favors both methanol supply and control of methanol crossover (MCO). With the increase in vaporization temperature, the cell performance can be enhanced. Based on the traditional structural design, a sintered porous metal plate is further used to depress the impact of MCO so that the cell performance can be significantly improved at a relatively higher methanol concentration. This is of great importance to enhance the energy density and operating duration for portable applications. The mechanisms related to the performance behaviors are discussed in detail.