Performance Analysis on Planar Micro PDMS Proton Exchange Membrane Fuel Cell Stack

Abstract

The objective of this study is to develop a micro proton exchange membrane fuel cell (PEMFC) stack, in which a flow field plate in each cell is made of polydimethyl-siloxane (PDMS) and manufactured by micro-molding technology. A four-cell micro PEMFC stack in series with a volume of 12 cm x 4.5 cm x 1.2 cm is constructed and tested. The active area of a membrane electrode assembly (MEA) is 2 cm x 2 cm in each individual PEMFC, and the platinum loadings at anode and cathode are 0.3 and 0.5 mg/cm(2), respectively. A series of performance experiments were carried out. Experimental parameters included clamping force and fuel supply condition. Durability tests were carried out as well. Experimental results showed that an appropriate clamping torque range should be considered carefully to enhance performance without narrowing down fuel flow channels. Under a torque of 2.0 kgf . cm, peak power density for this stack is 122.5 mW/cm(2) at 2.0 V. Increase in fuel flow rate is not the best way to improve concentration polarization in this air-breathing stack experiment because of limited air supply, and each cell in the same stack has a different performance under the present arrangement. At present, such stack can maintain a stable power output for a long time (up to 14 hours).