Thin and Robust Template‐Reinforced Anion Exchange Membranes for Fuel Cells, Oil‐Water Separation, and Humidity‐Responsive Applications

ABSTRACT Developing high‐performance thin and robust anion exchange membranes (AEMs) is crucial not only for enhancing the efficiency of alkaline anion exchange membrane fuel cells by reducing ohmic resistance and alleviating water imbalance but also for expanding their applications into areas such as oil‐water separation and humidity‐responsive technologies. Herein, thin and robust template‐reinforced AEMs were fabricated by incorporating a cross‐linked polyelectrolyte into a microporous polyethylene base membrane using a pore‐filling method, with dimethyl diallyl ammonium chloride as the monomer and triallyl amine as the cross‐linking agent. The resulting composite AEMs exhibit remarkable properties, including high ionic conductivity (173.16 mS cm −1 at 80°C), excellent mechanical strength (tensile strength > 150 MPa), and high dimensional stability. In an H 2 /O 2 fuel cell system at 60°C, a single cell utilizing the optimized AEM achieved a maximum power density of 159 mW cm − 2 , indicating its potential for fuel cell applications. Moreover, the AEM, with strong hydrophilicity and rapid response characteristics, shows promise in moisture‐responsive applications, oil‐water separation, and health monitoring. Its ability to recognize spoken words and respond to varying water vapor temperatures, combined with superior flexibility and mechanical strength, makes it highly suitable for medical and non‐contact human‐machine interaction applications.