N-sulfopropyl chitosan-based hybrid membranes enhanced with ionic liquid and covalent organic framework for...

This study presents a novel approach to developing high-performance acid-functionalized chitosan (CS) membranes for intermediate-temperature proton exchange membrane fuel cells (IT-PEMFC). We synthesized hybrid membranes by incorporating polyionic liquids (IL) and covalent organic frameworks (COF) into N-sulfopropyl CS (NCS). The addition of these components enhanced the membranes mechanical and thermal stability through strong hydrogen bonding and acid-base interactions. The optimized membrane, featuring a combination of glycerol (GY), IL, and COF, exhibited exceptional proton conductivity (1.53 × 10^-2 S cm^-1), power and current density (160 mW cm^-2) and 700 mA cm^-2 at 120 °C. The results demonstrate that the bio-hybrid membranes hold great promise for fuel cell applications, offering improved efficiency and performance. This work highlights the potential of CS-based membranes for energy conversion and storage devices, paving the way for further research and development in this field. The findings suggest that these membranes could be a viable option for intermediate-temperature fuel cells.