Journal Article

A functionalized separator enables dendrite‐free Zn anode via metal‐polydopamine coordination chemistry

Lu, Bingan, Zhou, Jiang, Liang, Shuquan, Xie, Xuesong, Liu, Yanfen, Li, Zhicheng, Liu, Shude, Wang, Pinji, Tang, Yan

2023

Overview

Designing a multifunctional separator with abundant ion migration paths is crucial for tuning the ion transport in rocking‐chair‐type batteries. Herein, a polydopamine‐functionalized PVDF (PVDF@PDA) nanofibrous membrane is designed to serve as a separator for aqueous zinc‐ion batteries (AZIBs). The functional groups (OH and NH) in PDA facilitate the formation of ZnO and ZnN coordination bonds with Zn ions, homogenizing the Zn‐ion flux and thus enabling dendrite‐free Zn deposition. Moreover, the PVDF@PDA separator effectively inhibits the shuttling of V‐species through the formation of VO coordination bonds. As a result, the Zn/NH4V4O10 battery with the PVDF@PDA separator exhibits enhanced cycling stability (92.3% after 1000 cycles at 5 A g−1) and rate capability compared to that using a glass fiber separator. This work provides a new avenue to design functionalized separators for high‐performance AZIBs. A polydopamine‐functionalized PVDF (PVDF@PDA) nanofibrous membrane is designed as a separator for aqueous zinc‐ion batteries. The PVDF@PDA separator homogenizes the Zn‐ion flux distribution to achieve the dendrite‐free Zn deposition via the metal‐PDA coordination chemistry. Moreover, the PVDF@PDA separator inhibits the shuttle of V‐species. Benefiting from the separator, the Zn/NH4V4O10 full cell retains 92.3% capacity after 1000 cycles at 5 A g−1.

• Publisher: John Wiley & Sons, Inc,Wiley
• Subject: aqueous zinc‐ion batteries / Cellulose / Contact angle / Coordination / coordination bonds / dendrite‐free Zn deposition / Dopamine / Electrolytes / Functional groups / Glass fibers / Ion flux / Ion migration / Ion transport / Mechanical properties / Membranes / Rechargeable batteries / Scanning electron microscopy / Separators / Vibration / Zinc