Regulating interfacial behavior of zinc metal anode via metal-organic framework functionalized separator

Aqueous zinc ion batteries (AZIBs) are one of the promising energy storage devices. However, uncontrolled dendrite and side reactions have seriously hindered its further application. In this study, the metal-organic framework (MOF) functionalized glass fiber separator (GF-PFC-31) was used to regulate interfacial behavior of zinc metal anode, enabling the development of high-performance AZIBs. In PFC-31, there are π-π interactions between two adjacent benzene rings with a spacing of 3.199 Å. This spacing can block the passage of [Zn(H2O)6]2+ (8.6 Å in diameter) through the GF-PFC-31 separator to a certain extent, which promotes the deposition process of Zn ions. In addition, the sulfonic acid group (–SO3H) contained in GF-PFC-31 can form a hydrogen bonding network with H2O, which can provide a desolvation effect and reduce the side reaction. Consequently, GF-PFC-31 separator achieves uniform deposition of Zn ions. The Zn||GF-PFC-31||Zn symmetric cell exhibits stable cycle life (3000 h at 1.2 mA cm−2, 2000 h at 0.3 mA cm−2, and 2000 h at 5.0 mA cm−2), and Zn||GF-PFC-31||MnO2 full cell with GF-PFC-31 separator can cycle for 1000 cycles at 1.2 A g−1 with capacity retention rate of 82.5%. This work provides a promising method to achieve high-performance AZIBs.