Thorn-like COF-Derived N-Doped Carbon Fibers Embedded with Cu Nanoparticles toward Dendrite-Free Zn Anodes

Rechargeable aqueous Zn metal batteries have emerged as compelling options for grid-scale energy storage applications, benefiting from a favorable combination of economic viability, operational safety, and excellent rate performance. The lifespan and Coulombic efficiency (CE) of Zn metal anodes (ZMAs) are constrained by dendrite growth and side reactions. Herein, we report a freestanding host for ZMAs based on N-doped thorn-like carbon fibers derived from a covalent organic framework (COF) and embedded with Cu nanoparticles (COF-NCF@Cu). The 3D macroporous architecture with thorn-like COF-derived N-doped carbon nanoarrays contributes to reduced current density and effectively mitigates electrode volume variation throughout cycling. Furthermore, the zincophilic Cu nanoparticles embedded in the N-doped carbon matrix provide homogeneous nucleation sites that significantly lower the overpotential for zinc nucleation, thereby promoting subsequent uniform zinc deposition. Accordingly, the COF-NCF@Cu host delivers exceptional reversibility, affording stable Zn plating/stripping for over 2800 h at 10 mA cm–2, and the corresponding full cell with a COF-NCF@Cu-Zn anode sustains 6000 cycles with negligible capacity decay.