An Electro-osmotic Fuel Pump for Direct Methanol Fuel Cells

This work reports on the design and performance evaluation of a miniature direct methanol fuel cell (DMFC) integrated with an electro-osmotic (EO) pump for methanol delivery. Electro-osmotic pumps require minimal parasitic power while boasting no moving parts and simple fuel cell integration. Here, an electro-osmotic pump is realized from a commercially available porous glass frit. We characterize a custom-fabricated DMFC with a free convection cathode and coupled to an external electro-osmotic pump operated at applied potentials of 4.0, 7.0, and 10 V . Maximum gross power density of our free convection DMFC (operated at 50 ° C ) is 55 mW ∕ cm 2 using 4.0 mol ∕ L concentration methanol solution supplied by the EO pump. Experimental results show that electro-osmotic pumps can deliver 2.0, 4.0, and 8.0 mol ∕ L methanol/water mixtures to DMFCs while utilizing ∼ 5.0 % of the fuel cell power. Furthermore, we discuss pertinent design considerations when using electro-osmotic pumps with DMFCs and areas of future study.