Solution-processed nitrogen-rich graphene-like holey conjugated polymer for efficient lithium ion storage

Preparing well-defined single-layer two-dimensional (2D) holey conjugated polymers (HCP) is very challenging. Here, we report a bottom-up method to produce free-standing single-layer nitrogen-rich graphene-like holey conjugated polymers (NG-HCP) nanosheets through solution-process. The as-prepared 2D NG-HCP sheet possesses a thickness of 1.0 ± 0.2 nm and consists of graphene-like subunits as well as homogeneous hexagonal micropores (ca. 11.65 Å). The synergistic effect of high porosity, heteroatomic doping and good dispersity of NG-HCP nanosheets make them suitable as excellent anode materials for Li-ion batteries (LIBs), leading to an extremely high reversible capacity of 1320 mAh g−1 (at 20 mA g−1), a good rate performance, and an excellent cycle life with an approximate 100% Coulombic efficiency for more than 600 cycles. Our findings would open new opportunities to develop state-of-the-art free-standing 2D-HCP materials for low-cost and high performance energy storage as well as optoelectronic devices.