Nanofiber membranes for enhanced performance and optimization of proton exchange membrane fuel cells.

Abstract

Proton exchange membranes (PEMs) are critical to fuel cell performance, where ion transport, catalyst activity, and mass transfer determine efficiency and durability. However, conventional membranes in PEM fuel cells often suffer from hydrogen crossover, limited conductivity, and poor interfacial stability. To address these challenges, this study develops a nanofiber membrane system with synergistic structural and interfacial enhancement. Through nanofiber architecture and surface engineering, the membrane balances proton conductivity, mechanical strength and electrochemical performance. The sandwich-structure nanofiber membrane (SSNFM) achieves a peak power density of 942 mW cm^-2 after 100-hour accelerated stress testing, substantially outperforming conventional commercial membranes (520 mW cm^-2). Electrochemical characterization confirms enhanced proton conductivity for SSNFM (40.4 mS cm^-1) compared to commercial membranes (17.5 mS cm^-1). Multiscale analyses, including x-ray computed tomography and multiphase simulations, reveal improved membrane properties, catalyst layer stability, and triple-phase boundary formation, facilitating efficient charge and mass transport. This work presents a membrane design strategy to enhance fuel cell performance in sustainable energy applications.