Molecular engineering regulation redox-dual-active-center covalent organic frameworks-based anode for high-performance Li storage

Abstract

Covalent organic frameworks (COFs) show considerable attention and potential value in energy storage and conversion. However, design and preparation novel dual-active-center modified COFs for high-performance Li storage and accelerating Li diffusion are still challengeable. In this work, we synthesize dual-active-group of C N and C O decorated COF (denoted as Tp-Ta-COF) as the anode material for lithium-ion batteries (LIBs). Benefiting from the dual-active-site, the Li+ diffusion kinetics on the Tp-Ta-COF are improved and Tp-Ta-COF electrode delivers high reversible capacity of 413 mAh g−1 under current density with 200 mA g−1. Moreover, 18 Li+ can be embed in Tp-Ta-COF with C N and C O containers. The mechanism between Li+ and active-site is deeply deduced and studied by multiple in situ techniques and density functional theory (DFT) theoretical calculation, suggesting interactions of Li+ and active-group are highly reversible procedures. Consequently, we expect this work could create a universal strategy for construction high-performance Li storage COF-based materials. (Figure presented.).