Regulating Zn Deposition via Honeycomb-like Covalent Organic Frameworks for Stable Zn Metal Anodes

The irreversible chemistry of the Zn anode, attributed to parasitic reactions and the growth of zinc dendrites, is the bottleneck in the commercialization of aqueous zinc-ion batteries. Herein, an efficient strategy via constructing an organic protective layer configured with a honeycomb-like globular-covalent organic framework (G-COF) was constructed to enhance the interfacial stability of Zn anodes. Theoretical analyses disclose that the methoxy and imine groups in G-COF have more negative adsorption energy and electrostatic potential distribution, favorable Zn²⁺ adsorption, and diffusion. Experimental results demonstrate that G-COF effectively protects the Zn anode from dendrite formation and surface corrosion, leading to a stable and homogeneous Zn²⁺ deposition. Notably, the G-COF@Zn||G-COF@Zn symmetric cell obtained high stability for over 1650 h under 3 mA cm^-2 for 1 mA h cm^-2. Full cells assembled with the δ-MnO₂ cathode and G-COF@Zn anode demonstrates exceptional rate capability and consistent cycling over 1000 cycles at a current density of 1 A g^-1, achieving a specific capacity of 217 mA h g^-1. Our work provides novel insight into interfacial regulation of Zn anodes for the implementation of practical aqueous zinc-ion batteries with long-term cycling characteristics.