Disrupting the Spatiotemporal Coupling of Side Reactions via Zn-Centered Covalent Organic Polymer Enables Highly...

Aqueous zinc-based batteries (AZBs) hold significant potential for large-scale energy-storage systems due to ultrahigh anode volumetric capacity and safe aqueous electrolyte environment. However, the positive feedback enhancement of multiple side reactions on the Zn anode interface accelerates the performance degradation of AZBs. Here, a Zn-centered covalent organic polymer (COP-Zn), serving as a solid-electrolyte interphase (SEI), effectively disrupts the coupling between temporal continuity and spatial overlapping of side reactions to enable dendrite-free Zn²⁺ deposition. Identified by in situ Raman spectroscopy, the N-N-H bonds create a water-deficient Zn²⁺ channel, inhibiting the hydrogen evolution reaction (HER). The N-Zn sites adjacent to the N-N-H bonds further capture the OH^- generated during the deposition process, thereby preventing hydroxide passivation around the nucleation sites. The spatiotemporal decouple process disrupts the continuous positive feedback loop near the deposition space of side reactions. Ultimately, the COP-Zn-coated electrode demonstrated stable cycling for over 9600 cycles at a current density of 20 mA cm^-2 in a symmetric cell, achieving about 19-fold improvement compared to the uncoated anode. The COP-Zn@Zn||Cu asymmetric cell showcases a Zn²⁺ stripping/plating process over 4700 cycles with an impressive average Coulombic efficiency of 99.61% at 5 mA cm^-2.