A MEMS-based reformed methanol fuel cell for portable power

A reformed methanol fuel cell system is described. The use of a microfluidic fuel processor enables component scaling and integration sufficient to achieve power sources in the 2-10 W regime that are competitive in size and energy density in comparison to alternative power sources. While carbon monoxide tolerance of proton conducting membranes has typically limited the performance of reformed methanol fuel cells, phosphoric-acid-doped polybenzimidazole (PBI) membranes have been tested that exhibit no degradation for carbon monoxide > 2% mole fraction. Further benefits of the PBI membrane include operating temperature of 150-200 degrees C, and no need for water to assist protonic conduction. As a result, a chemically and thermally robust fuel cell power source is realized. Results of methanol steam reforming and catalytic combustor heating elements formed in a silicon MEMS platform, and PBI membrane performance with reformate fuel feed will be discussed.