PEM Fuel Cell Investigationat Chiang Mai University, Thailand

Abstract

A Proton Exchange Membrane (PEM) fuel cell has been undergoing development in Thailandfor five years. A fuel cell testing station has been set up to measure and control the mass flow rate ofhydrogen (H2 ) and oxygen (O2 ), cell temperature, backing pressure and gas humidity. An interfacialunit and software have also been developed to provide significant data instantly. Membrane ElectrodeAssembly (MEA) was fabricated using solid electrolyte membrane, Nafion? 115, and platinum catalyst20 wt% on carbon particle. The study is devoted to test PEM fuel cell performance, by analyzing thecurrent density and voltage characteristics (I-V curve) and the current density and power density(I-P) curve, at various soaking conditions. It is found that the operating conditions which yield thebest cell performance are the following: relative humidity of hydrogen at 80% to 90%, and relativehumidity of oxygen at 50% to 60%; mass flow rate of hydrogen at 100 standard cubic centimeters perminute (sccm/min) and mass flow rate of oxygen at 140 sccm/min. These operating conditions yieldedthe maximum power density at about 150 milliwatts per square centimeters (mW/cm2) in reactionarea of 25 cm2. The performance of aluminum alloy (94% Al and 6% Si) as the gas flow field in placeof graphite was also investigated. It is found that the gas flow field made of aluminum alloy yieldedlower performance than that of graphite because of the oxide film at the surface of the aluminum alloy.