Enhanced Ionic Conduction Behaviors through the Synergistic Integration of MOF FJU-66 and PDDA for the Improving Performance in F-ZAB and AEMWE Applications

With the growing global emphasis on green economy goals, the development of flexible and sustainable energy storage devices has gained marked momentum. Among these, durable and high-performance anion exchange membranes (AEMs) used in flexible zinc–air batteries (F-ZABs) represent a critical area of ongoing research. This study presents an innovative bacterial cellulose (BC)-based alkaline exchange membrane, fabricated through a multi-step process involving the in situ growth of metal–organic frameworks (MOFs) FJU-66, in situ polymerization of poly(diallyldimethylammonium chloride) (PDDA), and subsequent chemical crosslinking to enhance membrane performance. The incorporation of FJU-66 markedly promotes the polymerization of PDDA, resulting in the formation of longer and more regular linear molecular chains. This structural refinement facilitates the construction of a long-range, ordered OH – transport channel within the membrane. The resulting BC@FJU-66/PDDA-B 10 membrane exhibits outstanding properties, including a high ionic conductivity of 162.2 mS/cm at 80 °C and excellent mechanical strength, with a tensile strength of 66.4 MPa. When integrated into an F-ZAB, the membrane delivers a remarkable peak power density of 282.4 mW/cm 2 . Additionally, in the context of alkaline water electrolysis (AEMWE) using a 30 wt % KOH electrolyte, the membrane achieves an impressive current density of 4.0 A/cm 2 at an applied voltage of 2.42 V. This fabrication approach offers promising insights into the design of high-performance AEMs, contributing to advancements in green energy technologies and environmental sustainability.