Ultralight Fluorine-Rich Covalent Organic Framework Composite Aerogel for Fast and Durable Zinc-Ion Storage.

Abstract

Organic electrode materials represent promising candidates for aqueous zinc-ion batteries (AZIBs) due to their structural tunability, sustainability, and cost-effectiveness. However, their practical application is impeded by sluggish ion transport, dissolution, and limited reversible capacity. Herein, an ultralight aerogel (F-COF@rGO) was constructed through the self-assembly of fluorine-rich covalent organic framework nanospheres and reduced graphene oxide into a three-dimensional hierarchical porous network. The incorporation of highly electronegative fluorine atoms enhances Zn²⁺ affinity, promotes electron delocalization, and improves conductivity, collectively facilitating Zn²⁺/H⁺ cointercalation and stabilizing reversible redox transitions. As a result, F-COF@rGO delivers a high reversible capacity, excellent rate capability, and outstanding long-term durability. In situ/ex situ characterizations and density functional theory calculations reveal that Zn²⁺/H⁺ costorage can be attributed to the synergistic porous architecture and fluorine-ligand-induced selective ion migration. This work establishes a molecularly engineered composite strategy for a fluorinated COF-based aerogel, advancing sustainable, high-performance organic electrodes for next-generation aqueous energy storage.