A Micro Direct Methanol Fuel Cell Using Platinum and Platinum-Ruthenium Electroplated Microchannel Electrodes

Abstract

This work studied the design, fabrication, and performance evaluation of a novel micro direct methanol fuel cell (µ-DMFC). A µ-DMFC of 0.018 cm² active area was prepared using a series of fabrication steps from micromachined silicon wafer including photolithography, deep reactive ion etching, and electron beam deposition. The novelty of this structure is that we have integrated the anodic and cathodic micro-channels arranged in plane onto a single silicon substrate. This architecture eliminates the need for the membrane electrode assembly (MEA) used in traditional polymer electrolyte-based fuel cells. Another original aspect is the successful electroplating of Pt and Pt-Ru catalysts in the microchannels. In addition, quasi-reference electrodes could be built in the prototype cell. The experimental trials were to verify the feasibility of this novel structure on basis of MEMS technology. The fuel and oxidant were supplied to the unit cell at a rate of 10 µL/min. Preliminary test results were able to confirm that this new concept of µ-DMFC generates electricity. At ambient temperature under atmospheric pressure, the maximum power density was 0.44 mW/cm² at 3 mA/cm² with Pt anode catalyst, while the maximum power density reached 0.78 mW/cm² at 3.6 mA/cm² for cell with Pt-Ru anode catalyst.