A tetrathiafulvalene-containing covalent organic nanobelt: preparation, crystal structure and application for sodium-ion batteries

Abstract

Developing single crystals of covalent organic polymers (COPs) is highly attractive as they can afford precise structural information for studying internal interactions. Employing dative boron–nitrogen (B–N) bonds to construct single-crystalline COPs is feasible since the dynamic linkages can self-correct errors, thus improving crystallization. In this project, we develop a single-crystal COP with a nanobelt structure, namely CityU-26, via B–N-driven-assembly between 4,4′,5,5′-tetrakis(4-(pyridin-4-yl)phenyl)-2,2′-bi(1,3-dithiolylidene) and 1,4-bis(benzodioxaborole) benzene. The B–N coordination between these units gives rise to one-dimensional (1D) nanobelts, and hydrogen bonding interactions between the nanobelts lead to the formation of a three-dimensional (3D) supramolecular structure. CityU-26 demonstrates an impressive sodium storage capability of 365 mA h g⁻¹ with a current density of 150 mA g⁻¹, and the capability could reach 315 mA h g⁻¹ at 750 mA g⁻¹. The outstanding sodium storage behaviors of CityU-26 underscore the functionalization of B–N polymers, providing a promising platform for the development of efficient energy materials.