Nitrogen-doped carbon dots@COFBTH-TT composite for high-performance lithium ions battery anode

Herein, a novel hollow rod-like composite was obtained by doping nitrogen-doped carbon quantum dots (NCDs) into covalent organic frameworks (COFs) (NCDs@COFBTH-TT) by a one-pot hydrothermal method. Such a hollow structure not only facilitates the transport of Li+ but also exposes a large number of active sites. The doped NCDs improve the electrical conductivity of NCDs@COFBTH-TT. When NCDs@COFBTH-TT was applied as the anode materials of lithium-ion batteries (LIBs), it showed excellent Li-storage performance. At a current density of 0.2 A g−1, the NCDs@COFBTH-TT exhibited an initial capacity of 336.8 mAh g−1 and then stabilized at 210.7 mAh g−1 after 226 charge/discharge cycles. This work combines zero-dimensional NCDs with two-dimensional COFs to improve the electrical conductivity and π-π stacking interaction of COFs, which is of great significance for the construction of COF-based LIBs with high storage capacity and ultra-long cycle life.