Underscoring Covalent-Organic Frameworks As Nanoengines for Zinc Anode Protection Coating

ConspectusRechargeable aqueous zinc-ion batteries (AZIBs) have emerged as promising energy storage systems owing to their high energy density, environmental benignity, and low cost. Nevertheless, the rough surface of the Zn metal anode can easily induce uncontrolled dendrite growth and parasitic reactions, which will limit the large-scale commercial applications of AZIBs. Owing to the diverse active sites and porous channels of covalent-organic frameworks (COFs), the exploration of COFs in this field affords a novel perspective in tackling the bottlenecks encountered through the anode of AZIBs. Based on reported works, this review summarizes the functions of COFs as nanoengines to manipulate the Zn²⁺ flux, hydrogen evolution, dendrite growth, and the electric field at electrode/electrolyte interface when applied as functional coatings. It also concludes the construction strategies of functional COFs coating and delves into strategies for protecting the Zn anode, with an emphasis on modulating Zn deposition dynamics and minimizing side reactions at the electrode/electrolyte interface. It further provides an evaluation of the current challenges and future expectations of AZIB, aiming to enhance their viability for grid-scale energy storage solutions.