2D Covalent Organic Frameworks: Organic Electrode Materials for Aqueous Batteries

Abstract

Two-dimensional covalent organic frameworks (2D COFs) have swiftly gained prominence as versatile organic electrode materials for aqueous batteries, driven by their insoluble skeletons, one-dimensional (1D) porous structures, and exceptional structural tunability. This review consolidates recent progress in the development of 2D COFs as cathode materials, addressing design principles, synthetic strategies, and electrochemical performance. It further underscores the wide-ranging applicability of 2D COFs across diverse aqueous battery, including proton, zinc-ion, calcium-ion, magnesium-ion, ammonium-ion, and hybrid acid–alkali systems. Finally, this review delineates critical challenges—such as conductivity enhancement, scalable synthesis, and interfacial stability—and proposes future research directions aimed at expediting the translation of 2D COF-based aqueous batteries from laboratory-scale prototypes to viable energy storage solutions, thereby catalysing innovation in sustainable battery technologies.