Dendrite-free and highly stable Zn metal anode enabled by fluorinated covalent triazine framework coating

Abstract

The inherent defects of zinc metal anodes, including unmanageable dendrite growth and intricate side reactions, pose significant obstacles to the progress of aqueous zinc-ion batteries. Here, a fluorinated covalent triazine framework (FCTF) is proposed as a protective layer for zinc anodes. The FCTFs with different specific surface areas are prepared by adjusting the amount of catalyst. The FCTF-5 layer, which has the highest specific surface area (903 m2 g−1), can expose more zincophilic sites (N atoms) reducing the nucleation overpotential and inducing uniform deposition of zinc. Moreover, the presence of F-containing nanochannels enhances ion transport while safeguarding against aqueous electrolyte penetration, thereby enhancing corrosion resistance. Therefore, the Zn@FCTF-5//Zn@FCTF-5 symmetric cell can cycle stably for more than 8000 h at 0.5 mA cm−2. Meanwhile, the Zn@FCTF-5//CVO full battery demonstrates a high initial discharge capacity of 311.1 mAh g−1. This work presents a promising approach for tackling the challenges associated with anodes in zinc-ion batteries.