Comparison on the impact of membrane thickness on the performance of proton exchange membrane-based electrochemical devices

Abstract

This study investigates the impact of membrane thickness on the performance of proton exchange membrane fuel cells (PEMFCs) and proton exchange membrane water electrolyzers (PEMWEs). Four different Nafion™ membranes with varying thicknesses (25, 50, 127, and 183 μm) were used to obtain polarization curves for both devices, and electrochemical impedance spectroscopy (EIS) was employed to analyze their electrochemical characteristics. The results demonstrate that membrane thickness significantly influences the performance of both systems, with PEMWEs showing greater sensitivity to thickness variations compared to PEMFCs. This heightened sensitivity in PEMWEs can be attributed to the distinct operational environments and performance demands of each system. While thinner membranes improve performance in both devices by reducing resistance and enhancing conductivity, the degree of this impact varies due to differences in current density, water management, and gas crossover risks. In addition, the greater sensitivity of PEMWEs may also be driven by their harsher operating conditions, including higher current densities and complex water transport phenomena. These factors are more pronounced in PEMWEs, making them more sensitive to membrane thickness than PEMFCs. Thus, we conclude that optimizing membrane thickness is essential for achieving a balance between efficiency, durability, and operational stability in both PEMFCs and PEMWEs, with PEMWEs requiring more careful consideration due to their increased sensitivity to these factors.

Acknowledgements This work was supported by the Korea Research Institute of Chemical Technology Core Research Program funded by the Korea Research Council for Industrial Science and Technology (grant number KS2422- 20). Additional support was provided by a grant from the Endowment project of “Development of Basic Technologies in Eco-friendly Ship Fuel Reliability and Safety Evaluation” funded by Korea Research Institute of Ships and Ocean Engineering (2520000279(PES5100)). This research was also supported by the National Research Foundation (NRF) funded by the Korean government (MSIT) (No. RS-2024-00351855).