Optimization of Ionomer for High-Performance Self-Humidifying Air-Breathing Proton-Exchange Membrane Fuel Cells in Portable Device Power Systems

This study investigates the impact of ionomer types and content in the catalyst layer on the performance of proton exchange membrane fuel cells (PEMFCs) under room temperature and atmospheric pressure. Four commercially available ionomers with varying equivalent weights (EWs) and side-chain lengths are evaluated as catalyst layer binders in membrane-electrode assemblies (MEAs). The assessments are conducted at room temperature and ambient pressure without additional humidification, focusing on understanding the distinctive characteristics of each ionomer. In addition, this study investigates the prospective application of an air-breathing passive-type cell, dependent exclusively on natural convection for air supply. The notable performance of the passive-type cell shown in this study indicates its suitability as a compact mobile power source, especially for drone applications. Furthermore, the stability of various ionomer binders is also compared to establish a correlation between EW and side-chain length of ionomer binder stability. Overall, the findings will serve as a valuable reference for optimizing ionomer selection and composition in specialized applications for powering portable devices.