Exploring Covalent Organic Frameworks as High-Capacity and Long-Cycling Anode Materials for Lithium-Ion Batteries

Abstract

It is important to develop lithium-ion batteries (LIBs) with high specific capacity and long cycle life. Covalent organic frameworks (COFs) are the "superstars" to realize this goal because of their long-range ordered porous structure and easy modification. In this work, we designed and synthesized two kinds of β-ketoenamine-linked COFs with multiple redox sites: TP-3J-COF and TP-3Q-COF, and applied them to the anode of LIBs, successfully preparing batteries with both high specific capacity as well as long cycle life. Next, two composites were prepared by growing COFs on carbon nanotubes (CNTs) in situ. Thanks to the synergistic effect of COFs and CNTs, TP-3J-COF@CNT and TP-3Q-COF@CNT exhibit maximum specific capacities of 1020 mAh·g-1 and 731 mAh·g-1, and cycle lives of over 1400 and 3000 cycles, respectively. This work indicates that the strategy of constructing COFs with multiple redox-active units and composite with CNTs is a powerful way to develop high-performance LIBs.

Keywords: Covalent organic framework, COF@CNT, lithium-ion battery, Anode, high-performance