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

We propose a novel design, fabrication and testing for a micro direct methanol fuel cell (μDMFC1) 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 32 ml/min, and methanol concentration (C) of 0.5, 1, and 2 M through both steady VI/PI measurements and transient (dynamic) electrochemical impedance spectroscopy examination (EIS2). With 8 cells in series on the substrate, we achieve an open circuit voltage (OCV3) of 4.5 V and a maximum power density of 27.5 mW/cm2 (@ 2.0 V) under a specific working condition (T = 60 °C, QMeOH = 16 ml/min, C = 1 M).

► A planar DMFC stack test was conducted and results were analyzed and discussed. ► A novel DMFC stack was made which is much easier to remove CO2 and H2O in channel. ► Eight μDMFCs were fabricated via a LIGA-like microfabrication process. ► Performance tests with VI/PI measurements and EIS examination were performed.