Synthesis of a pyridine-based covalent organic framework as an anode material for lithium-ion batteries

Abstract

Covalent organic framework (COF) materials with redox activity have emerged as promising electrode materials for lithium-ion batteries. Among them, two-dimensional COF (2D-COF) materials have attracted great attention due to their high surface area, layered structure, size-adjustable pores, and abundant redox sites. In this work, a novel 2D-COF containing pyridine units (denoted as TpBpy) has been successfully synthesized, and its application as an anode material for lithium-ion batteries has been investigated. TpBpy exhibits excellent performance as an anode material in lithium-ion batteries; an activation effect can be observed and a high specific capacity value (365 mA h g⁻¹) is recorded at a current density of 1 A g⁻¹. The materials have been characterized by XRD, SEM/TEM, XPS, etc. In addition, to gain further insight into the mechanism of the materials, a calculation/simulation has been conducted, and the computational results show that the oxygen and nitrogen atoms in the TpBpy framework provide abundant sites for lithium adsorption. At the same time, the interlayer structure of TpBpy also provides space for the intercalation of lithium ions. Each unit cell of TpBpy can hold 20 lithium atoms. The good performance of the TpBpy electrode in battery and the interpretation of its lithium storage mechanism may provide a valuable reference for the development of COF electrode materials in the future.