Robust Zinc Anode Enabled by Sulfonate‐Rich MOF‐Modified Separator
Ruwei Chen, Gengyuan Zhang, Hujing Zhou, Jian‐Rong Li, Jiangtao Li, Lai‐Hon Chung, Xuanhe Hu, Jun He
Abstract
Abstract Aqueous zinc ion batteries (ZIBs) hold great promise for large‐scale energy storage; however, severe zinc dendritic growth and side reactions on the anode dramatically impede their commercial application. Herein, a Zr‐based MOF (UiO‐66) functionalized with a high density of sulfonic acid (─SO 3 H) groups is used to modify the glass fiber (GF) separator of ZIBs, providing a unique solution for stabilizing Zn anode. Benefiting from the strong interaction between zincophilic −SO 3 H and Zn 2+ , this sulfonate‐rich UiO‐66 modified GF (GF@UiO‐S2) separator not only guarantees the homogeneous distribution of ion flux, but also accelerates the ion migration kinetics. Hence, the GF@UiO‐S2 separator promotes uniform Zn plating/stripping on the Zn anode and facilitates the desolvation of hydrated Zn 2+ ions at the interface, which helps guide dendrite‐free Zn deposition and inhibit undesired side reactions. Accordingly, the Zn||Zn symmetric cell with this separator achieves excellent cycling stability with a long cycle life exceeding 3450 h at 3 mA cm −2 . Besides, the Zn||MnO 2 full cell paired with this separator delivers remarkable cyclability with 90% capacity retention after 1200 cycles. This design of metal–organic frameworks functionalized separators provides a new insight for constructing highly robust ZIBs.