Enhanced performance of flexible polymer electrolyte membrane fuel cells with functional interlayer of heat- and acid-treated carbon nanotube sheets

In recent years, the development of flexible power sources has become a crucial research area due to the rapid advancement of flexible electronic devices. Among these, the flexible polymer electrolyte membrane fuel cells (PEMFCs) have attracted considerable attention. However, flexible PEMFCs still exhibit low power density. Here, the study aims to enhance the performance of flexible PEMFCs using carbon nanotube (CNT) sheets. In this study, we inserted raw and purified CNT sheets into flexible PEMFCs and compared their performance. The results showed that the flexible PEMFC with purified CNT sheets performed well at all curvatures, especially at kappa = 0 m-1, where it outperformed other flexible PEMFCs by 78%, and at kappa = 15.6 m-1, the peak power density reached 103.2 mW cm-2 . This improvement was attributed to the improved contact resistance due to the modified surface of the purified CNT sheets. This research demonstrates the potential to enhance the performance of flexible PEMFCs through a simple method, contributing significantly to the commercialization and industrial application of flexible power source technology.