A Novel Strategy to Functionalize Covalent Organic Frameworks for High-Energy Rechargeable Lithium Organic Batteries via Graft Polymerization in Nano-Channels

By introducing catalyst- and solvent-free graft polymerization of low cost and environmentally benign sulfur to the nano-channels of an imine-linked covalent organic framework (COF), we demonstrated our strategy for functionalization of a conventional COF to yield a redox-active covalent organic framework-graft-polysulfide (COF-graft-PS), which can be utilized as a cathode active material in rechargeable lithium organic batteries. The COF-graft-PS-based batteries showed high capacity (425 mA h g−1 at a rate of 250 mA g−1), excellent rate capability, and good cycling performance over 500 cycles. The design characteristics and synthetic strategy open new possibilities for the preparation of alternative, sustainable, high-performance rechargeable lithium batteries by using abundant and cost-effective materials.