Imide-based covalent organic framework with excellent cyclability as an anode material for lithium-ion battery

Covalent organic frameworks (COFs) exhibiting reversible redox behaviors have been identified as promising candidates for constructing electrode materials in lithium-ion batteries (LIBs). However, their extensive application has been limited due to finite redox sites and poor structural stability. In this study, we design and synthesize a novel polyimide covalent organic framework (PI-COF) using the traditional solvothermal method and successfully apply it as an anode material for LIBs. The large conjugated structure of PI-COF accelerates charge transfer, while its large surface area provides more active sites, making PI-COF an attractive anode material for LIBs. Furthermore, the PI-COF anode material demonstrates high reversible specific capacity and excellent long-term cycling stability due to its COF characteristics. Specifically, the PI-COF electrodes deliver a specific capacity of 800 mAh/g at a current density of 200 mA/g after 200 cycles, while a specific capacity of 450 mAh/g at a current density of 1000 mA/g is sustained after 800 cycles. The outstanding lithium storage capacity, particularly the satisfactory long-term cycling stability, establishes PI-COF as a promising material for LIBs.