Fluorine-rich zincophilic covalent organic frameworks enabling anti-corrosion and uniform zinc deposition for aqueous zinc metal battery anodes

Abstract

Aqueous zinc metal batteries (AZMBs) are a promising alternative for next-generation secondary batteries owing to their high safety, low cost, and high electrical capacity. However, issues such as corrosion and dendrite growth on zinc anodes hinder the practical application of AZMBs. In this study, we developed two two-dimensional fluorine-rich covalent organic frameworks (COFs), TpFPa and TpFBD, as protective layers for the AZMB anode. The fluorine-rich hybrid interface composed of COFs@Zn and ZnF₂, produced during Zn electroplating, promoted Zn²⁺ dissolution and homogenized the Zn²⁺ flux. These effects effectively inhibited side reactions and Zn dendrite growth. In addition, the uniform and dense COFs prevented direct contact between Zn and the electrolyte, which improved the corrosion resistance of the zinc anode. Thus, the symmetric cells assembled using COFs@Zn demonstrated a stable cycle performance of over 1680 h at 1 mA cm⁻²@1 mAh cm⁻², which significantly surpassed the performance of bare zinc symmetric batteries. In addition, full cells protected by COFs maintained an ultra-long cycle stability of over 3500 cycles at 2 A g⁻¹. This strategy of developing a fluorinated artificial interface layer represents a promising approach for designing high-performance AZMBs.