A novel membrane electrode assembly design for proton exchange membrane fuel cells: Characterization and performance evaluation

Abstract

Conventional membrane-electrode assembly (MEA), a key component in proton exchange membrane fuel cells, only operates reasonably within a narrow range of operating conditions. In this study, a scaled-up MEA that can perform adequately under a wide range of humidification and flow conditions is developed. It consists of a microporous layer (MPL) composed of graphene for the cathode electrode, catalyst layers (CLs) prepared with a short-side-chain (SSC) ionomer, and a SSC electrolyte membrane. The results show that the graphene-based MPL employed on the cathode provides an excellent platform for the CL (hence promotes catalyst activity and catalyst utilization) and improves water retention, due to its unique microstructure and morphology. The proposed MEA provides stable and highly promising performance independent of flow conditions under the relative humidities (RHs) of 70% and 100%. Interestingly, the MEA also demonstrates relatively better cell performance under low-humidity conditions (40% RH), such that it performs noticeably better, as the reactants are supplied to the cell under low-flow condition, rather than moderate- and high-flow conditions.