Anion-exchange membrane fuel cells (AEMFCs) are of significant interest due to their potential for employing platinum group metal (PGM)-free catalysts and less-expensive cell components. Despite substantial progress in power output and durability, effective water management within AEMFCs remains one of the critical challenges, hindering further durability improvements. Operating at higher temperatures offers a practical way to simplify water management, however, high-temperature AEMFCs (HT-AEMFCs) operated at 100 °C and above are yet to be developed.
Recently, collaborative research groups led by Prof. Michael D. Guiver and Prof. Yan Yin from the State Key Laboratory of Engines of Tianjin University and Prof. Dario R. Dekel from Technion—Israel Institute of Technology, reported on HT-AEMFCs operating at 100 °C, with balanced water management (greatly alleviated mass transport issues in polarization testing and no obvious voltage oscillations in durability testing), high power output (~2 W cm−2 peak power density) and remarkable stability (195-h operation with 140 mV h−1 (~4%) voltage decay rate). The realization of high-performing HT-AEMFCs results from both simplified water management enabled by increased temperature, and lightly branched poly(arylene piperidinium) AEM design for better membrane water management, and other sufficiently good all-round properties. The mechanism of lightly branched polymer structure design to regulate membrane properties, particularly membrane water management, is verified through simultaneous effects of chain entanglement and free volume. This relatively simple molecular branching strategy is promising in other AEM systems, such as poly(arylene alkylene) membranes.
Furthermore, the viability of lightly branched AEMs in HT-AEMFCs represents significant progress in the development of this research field, holding great potential for addressing water management issues and enhancing AEMFC durability.
The research result was published in the journal Joule, and the link is as follows: https://doi.org/10.1016/j.joule.2024.02.011
Editor: Eva Yin
