A Bifunctional Separator with Gradient Distribution of MCM‐41 Zeolite for High‐Performance Aqueous Zinc‐ion Batteries

Abstract Aqueous zinc‐ion batteries (AZIBs) are promising candidates for large‐scale energy storage systems. However, the dissolution of cathode materials, the corrosion and dendrites growth of Zn anode seriously impede their further development. Herein, a bifunctional separator with gradient distribution of MCM‐41 zeolite is designed to stabilize both the cathode and Zn anode simultaneously. Specifically, one side with heavy zeolite distribution can decrease the de‐solvation energy barrier and regulate the zinc‐ion flux, thus inhibiting the hydrogen evolution reaction (HER) and related side reactions, also promoting uniform zinc deposition. While the other side with light zeolite distribution and relative dense polymer can inhibit the dissolution and shuttle of VO 2 + , thus realizing stably cycling of V 2 O 5 cathode. With this bifunctional separator, cycling life of the assembled Zn//Zn symmetric battery exceeds 2400 h (1 mA cm −2 , 1 mAh cm −2 ). The full‐battery using commercial V 2 O 5 as cathode materials keeps a high capacity of 212.5 mAh g −1 even after 1000 cycles at the current density of 1 A g −1 . This work provides a promising direction for developing functional separator to stabilize both anode and cathode electrodes.