Impact of Cathode Fabrication on Fuel Cell Performance

Abstract

Hydrophobicity is generally believed to be key to water management in polymer electrolyte fuel cells (PEFCs). However, we reported that the membrane electrode assembly (MEA) using a hydrophilic micro porous layer (MPL) showed much better performance in a wide range of pressure and humidity conditions than that using a hydrophobic MPL. When operating an MEA, it usually needs to be humidified in order to maintain conductivity of the membrane. Operation without humidification is critical to the commercialization of PEFCs for backup power and automotive applications. We, therefore, evaluated MEAs at 60°C, at the H2/air stoichiometric ratio of 1.4/5.0, without humidification, in addition to the normal conditions of 80°C, 100 & 30%RH. We found that the MEA employing a gas diffusion electrode (GDE) method on the hydrophilic MPL showed the best performance under a very dry condition, suggesting that the firm interface between the catalyst layer and the MPL plays a crucial role in determining MEA performance, particularly under dry conditions