Design, fabrication and characterization of micro-electro mechanical system based micro direct methanol fuel cell stacks

Abstract

We propose a novel design, fabrication and testing for a micro direct methanol fuel cell (μDMFC11μDMFC, micro direct methanol fuel cell.) stack. Eight μDMFCs are fabricated on a copper metal sheet substrates via a LIGA-like microfabrication process of deep UV lithography, and integrate in series for an examination of the effect of the operating parameters of the stack temperatures (T) of 25°, 40° and 60°C, as well as the methanol feeding rates (QMeOH) of 4, 8, 16, and 32ml/min, and methanol concentration (C) of 0.5, 1, and 2M through both steady VI/PI measurements and transient (dynamic) electrochemical impedance spectroscopy examination (EIS22EIS, electrochemical impedance spectroscopy.). With 8 cells in series on the substrate, we achieve an open circuit voltage (OCV33OCV, open circuit voltage.) of 4.5V and a maximum power density of 27.5mW/cm2 (@ 2.0V) under a specific working condition (T=60°C, QMeOH=16ml/min, C=1M).